Types of descriptions technical systems.

As stated above, in order to obtain the most complete description of a complex technical system, it must be produced from different positions. Of the many aspects of descriptions, it is advisable to highlight five main and most consumed ones, namely:

1) structural, 2) functional, 3) cybernetic, 4) temporary and

5) technological.

Other aspects, such as economic, aesthetic, ergonomic and others, can be used to create descriptions that have a special purpose.

In accordance with the above-mentioned aspects, we will highlight five main types of descriptions (Fig. 1.4) and consider their features.

Construction description should give an idea of the structure (structure) of the system, its shape (configuration), materials from which parts of the system are made, substances used as working fluids (Fig. 1.5).

The structure of a complex system, which is considered in the structural description, is, as a rule, hierarchical in composition; in this case, the connections used to describe the structure characterize the relative position of the subsystems, as well as their belonging to one or another level of the hierarchy. The breakdown of the system at the level can be done based on constructive or technological considerations. For example, all engine units may belong to one level, assembly units to another, and parts to a third.

The main traditional way of describing the form (configuration) of technical systems is the use of sketches, drawings, and verbal descriptions. The creation of automated design systems required the development of special languages and methods for digitally describing the shapes of various geometric surfaces, the relative positions of structural elements, etc., suitable for entering information into a computer.

Methods for structural description of systems are usually standardized in one form or another. Standardization is carried out within the framework of the Unified System design documentation(ESKD.)

The structural description does not give an idea of the properties of the system during the work for which it should be used . For these purposes it is necessaryfunctional description , which consists of descriptions of the sequence of system states under the influence of supersystems (or the external environment) and descriptions of the processes that determine these states .

The main way to describe the processes that take place in a system is their decomposition into elementary ones, for example, the processes of mass and heat transfer, energy conversion in accordance with physical laws. This internal method functional description. An external method is to represent processes either in the form of a family of functioning characteristics, or in the form of a set of numerical values of system parameters corresponding to one of its states. Functional characteristics are called the dependences of the numerical values of the system parameters on the indicators that determine its state during operation . Speed characteristics of engine loads - typical example characteristics of its functioning.

IN general case state of the system at a given point in time t is determined by the parameters that characterize its external connections, the initial state at t= t0, as well as time interval D t= t – t0.

The state of the engine during its operation is usually called the operating mode. Engines can operate in different modes:

stationary (permanent),

unsteady (transient), forced rotation, etc.

For stationary operating modes, the state of the engine is determined by parameters that characterize the state of the working fluids: air, fuel, oil and water (with water cooling) - at the inlet and the external environment - at the outlet of the engine, as well as parameters that determine the state of the energy consumer (usually This is the power and rotational speed of the crankshaft). For non-stationary modes, the state of the engine is additionally determined by parameters that characterize the beginning and time of the transient process.

Knowledge of operating characteristics is necessary for studying systems, for predicting their behavior in different situations, as well as for comparing systems with each other. . In particular, comparison with a system taken as a standard is often used to determine the degree of conditioning of the system under study.

To carry out a functional description of a subsystem, it is necessary to isolate it from the system, defining external connections, and determine its state. The structure of its functional description as an information system is usually hierarchical. Possible presence of all three types of hierarchies:

on management, I will compile a detailed description.

The number of hierarchy levels depends on the purposes for which the description is being compiled and the amount of our knowledge about the system.

In Fig. 1.6 presents a fragment of the structure of the functional description of the system.

Due to the fact that the peculiarities of the functioning of technical systems are largely determined by the laws and means of controlling them, it is advisable to highlight a separate aspect of the description - cybernetic , purpose which is to identify the management structure, as well as the characteristics of the functioning of the system in the management process.

System control can be external - from the supersystem, internal - due to one of the subsystems that carries the function

control, or combined - from the supersystems using the control subsystem. Systems , which have internal management, are called automatic.

In general, four level management hierarchies can be distinguished (Fig. 1.8). At the lowest level of the hierarchy there is the so-called direct control, carried out to maintain a given system operating mode in a stabilized state. A control system corresponding to the next level of the hierarchy allows one to analyze the state of the controlled system when actions on it change, for example, from the external environment, find optimal control in accordance with a given control algorithm and implement it using appropriate regulators and actuators. This is an optimal control system. At the highest level is the adaptive control system, which allows you to automatically make adjustments to the optimal control algorithm during the control process.

And finally, if it is necessary to control several systems, it is possible to use integrated control, a feature of which is the presence of additional functions for mutual coordination of the operation of managed systems.

It is obvious that a technical system, in the structure of the control system of which there are levels of optimal adaptive and sometimes complex control, can be considered cybernetic.

The methods for constructing the characteristics of the functioning of objects in the management process have much in common with the methods for constructing the characteristics of functioning in the functional description of systems, so we will not dwell on this separately.

We can assume that any technical system, in accordance with the sign of variability, is prone to the laws of development determined by the general laws of technical progress. “The development of systems, accompanied by changes in their properties, structure, scope, etc., must be reflected in time by their description. Using a time description, one can trace all stages of development, for example, diesel engines from the first, built by G. Diesel, to modern ones. The need for a temporary descriptions becomes especially acute in prognostic studies.

A temporary description of the system can also be linked to all stages of its creation (Fig. 1.9). In this case, it can be used for planning purposes, determining the timing of systems modernization, changing basic models etc.

In order to manufacture a system, it is necessary not only structural, but also technological description . Strictly speaking, a technological description is a description of only a given technical system; it is, first of all, a description of the results of operation production system, within which this system is manufactured. But if we consider that in most cases the design of a technical system and the features of its functioning are determined by production technology, the need to include a technological description in the range of aspects of describing systems becomes obvious.

Technological description must include a description technological operations processing of materials from which the system is made, testing technologies for subsystems and the entire system, etc. The technological description must be carried out in accordance with the Unified System of Technological Documentation (ESTD).

Lecture 3. System quality indicators.

The full use of structural, functional, cybernetic and other types of descriptions is, as a rule, inconvenient for the purposes of monitoring and managing systems, as well as for comparing the latter with each other. In this regard, the need arose to use a more compact form of description of systems in the form of a set of numerical values of parameters defined for any one (for example, nominal) or several states of the system.

The number of parameters of a complex system, characterizing its properties, can be quite large, in principle infinite. At the same time, it is possible to identify a significantly smaller group of the most important of them, characterizing with sufficient completeness the ability of the system to provide the properties of the supersystems of which it is a part. Representatives of this group of parameters are called quality indicators.

The whole set of quality indicators can be divided into:

1) indicators that directly characterize the properties of the system,

2) indicators that characterize the properties of other systems transferred to this system.

The first group of indicators can, in turn, be divided into the following subgroups:

1) indicators that determine the main technical properties systems, such as power, throttle response, reliability, engine weight;

2) ergonomic indicators, for example, characterizing vibration, noise, smoke of engine exhaust;

3) operational and economic indicators, which are, for example, an assessment of the costs of fuel, oil, engine maintenance during its operation;

4) aesthetic indicators, for example, characterizing the proportionality of shapes, harmony and integrity of the engine design.

Among the indicators that characterize the properties of other systems, separate subgroups can also be distinguished:

1) production and technological indicators, characterizing the labor intensity of manufacturing the system, the degree of use of materials;

2) production and economic indicators, for example, such as the cost and price of the engine; indicators of standardization and some indicators of unification, characterizing the number of elements common to other systems.

To ensure the necessary completeness, reliability and convenience of describing systems, it is desirable that the parameters used in the form of quality indicators are quite simple to define, give a clear and adequate idea of the properties for which they are intended to evaluate, have good sensitivity to changes in these properties and are stable to random obstacles in the process of identifying them (measurement) . In this regard, identifying the nomenclature of quality indicators is not an entirely simple task. Often, to select the minimum number of quality indicators, they use special methods, for example, the method of expert assessments.

For using quality indicators instead full description the system has to pay with an error determined by the incompleteness of information, which lies in each indicator. Obviously, the smaller the number of quality indicators, the higher the error.

Quality indicators can characterize one or more properties of the system. In the first case, they are called single quality indicators, in the second - complex ones. If the properties of the system as a whole are assessed by one indicator, then this indicator is called the defining quality indicator (GOST 1547-79). Sometimes in the literature the defining indicator of the quality of a system is called an indicator of its effectiveness.

Quite often, relative indicators are used, which are the ratio of the quality indicators of a given system and the system taken as the standard. The set of relative quality indicators characterizes the quality level (technical level) of the system.

Entire systems.

Any description of a technical system can be considered incomplete if we do not consider the degree to which its properties satisfy the needs of the systems. higher order and, ultimately, society. Providing for the total needs of society can be considered the main ultimate goal of creating a system or, more simply put, the main goal of the system .

The needs of society, formed at the level of technical systems of a certain type, must be satisfied in three closely related categories:

1) quality,

2) quantities,

3) the nomenclature of these systems.

In particular, society's need for internal combustion engines must be satisfied by the quality of each engine, the range of engines and the number of engines of each type.

If we do not know to what extent this need is being satisfied, then all the aspects of the description discussed above will not be of significant importance, since we will not be able to say the most important thing about the system: whether it is good or bad, whether its use is appropriate or not.

Society's need for technical systems is divided into the needs of domestic and foreign markets, the need of the domestic market into the needs of industries national economy, the needs of each industry - the needs of individual consumers, etc. In this regard, the main (ultimate) goal of the system can be divided into components, so-called subgoals, and those into even smaller subgoals, etc. The result is a hierarchical structure of goals, which is sometimes called a goal tree (Fig. 1.10).

The goal of the system is broken down into subgoals in order to logically link this goal with the means of achieving it through its components. The tree of goals, as a rule, is built from top to bottom - from the main goal to subgoals, and the provision of goals, obviously, should be carried out from top to bottom. First, the goals of the lowest level are achieved, then with their help (they are, as it were, means of achieving) the goals of the nearest upper level, etc., until the main goal is achieved.

Due to the fact that the quality of a system is the totality of its properties that determine the satisfaction of the goals of its creation or application, quality indicators carry two functions:

firstly, they make it possible to describe entire systems,

secondly, using numerical expressions to assess the degree of satisfaction of these goals.

Entire system creations can be formulated in different ways:

1) acquire the best (optimal) properties (quality);

2) purchase best properties when there are restrictions, for example on human, material, financial resources and time;

3) acquire the specified properties.

Let the main goal when designing a system be to obtain the property f , measured using the quality indicator F . Then, in order to obtain the best quality, it is necessary to create such a design of the system or provide such conditions for its operation under which the indicator F will take the optimal value.

Considering that optimization of systems is a very important and serious problem, it is advisable to dwell on some optimization concepts that will be useful to us in the subsequent presentation.

Basic concepts of optimization.

The word “criterion” is of Greek origin and can be translated as “measure of evaluation.” If an optimization problem is resolved using any criterion, then we are dealing with an optimum (optimization) criterion. The criterion discussed above F is the optimum criterion.

When solving some optimization problems using mathematical models, it is not always possible to compare options according to the selected optimum criterion. Sometimes it cannot be identified explicitly and it is necessary to find other parameters that indirectly characterize the changes; sometimes the assessment is carried out according to the function that includes this criterion.

In the theory of operations research, the function by which the degree of optimality of a solution on a mathematical model is assessed is called the criterion, or target, function. The objective function does not coincide with the optimum criterion when using penalty function methods, when solving multicriteria problems, etc.

There is one more difference between the optimum criterion and the objective function. The optimum criterion may not have a mathematical formulation, but consist of concepts presented at a verbal, content level. The objective function always has a mathematical formulation.

May exist different cases optimal solutions.

1. The objective function may have one or more extrema. The largest (smallest) of the extrema is called the global extremum maximum (minimum). Depending on the number of extrema, the objective functions are called single- or multi-extremal (sometimes uni- or polynomials).

2. The optimal value of the objective function is achieved inside or on the boundaries of the feasible region. A local extremum that lies on the edge of the permissible region is called a conditional maximum or minimum (Fig. 1.13).

The selection of optimal criteria and the formation of areas of feasible solutions is carried out on the basis of an analysis of the goals of the system. Let's give an example. Let it be necessary to create an engine for a generator drive (1st goal), providing maximum power (2nd goal) with given maximum dimensions (3rd goal). Then the optimum criterion can be taken as the value of effective power at the nominal mode (at engine speed, even generator rotor speed), and the range of permissible solutions will be determined by restrictions on the speed and design dimensions of the engine.

Due to the existence of many goals when optimizing a system, many criteria can be used to evaluate the optimum. Representatives of this set are called private, or local, criteria.

If the optimization of a system is carried out according to a single criterion, which characterizes its main (from the point of view of the supersystem) properties, then such a criterion is calledglobal .

If the optimization process of a technical system involves criteria that evaluate the properties of subsystems that belong to different levels hierarchy, then it is advisable to call these criterialocal , or private criteria of the total hierarchy level.

Optimal system.

In order to identify the best system from the available set of systems, it is necessary to assign an optimum criterion and compare its values obtained for each of the systems in the set . All other things being equal, the optimal system will be the one in which the value of the criterion will have an extreme value . Will such a system be the best in all aspects? No, because one criterion cannot completely describe the system. In order to optimize a system according to properties not covered by the selected criterion, it is necessary to introduce other optimum criteria, that is, move on to a multi-criteria optimization problem, and solving the latter objectively and unambiguously is, as a rule, impossible.

When there are several optimum criteria, it is usually impossible to find a solution that delivers an extremum to all of them at the same time. Let us explain this using the following simplified example of engine optimization according to

two optimum criteria.

Let the first criterion be the effective engine power at rated mode Ne, second - engine time between failures T. We will consider engine options that differ only in the crankshaft rotation speed at nominal mode. Let the nature of changes in these criteria be the same as in Fig. 1.14, where extreme points are indicated by asterisks. From the figure it can be seen that the maximum time between failures T* achieved at crankshaft speed p1, A maximum power Ne- at p2. The best option for a system (i.e. engine) in which simultaneous T= T* And Ne = N*e, in our problem, obviously, it cannot be.

From the above example it turns out that any decision by choice the best option when the number of optimal criteria is more than one, as a rule, it will be a compromise. What is hidden in the above definition of the optimum behind the expression “many possible systems”.

If, when searching for an optimal solution in a single-criteria problem, the variable parameter changes in the range A £ x £ b, then you can sort through all its values in one way or another and thereby find the extremum of the optimum criterion. When we consider options for constructive ideas and want to design a technical system that is optimal according to the constructive idea that underlies it, then we even theoretically do not have the opportunity to go through all the solutions, because the number of indicators that characterize the constructive idea is uncertain, and it may be endless. From this it is clear that in a strict sense it is impossible to create an optimal system, and therefore an optimal internal combustion engine system.

At the same time, to distinguish engines and their systems from others created by traditional methods, We will call an optimal engine (system) one over which the optimization procedure was carried out using one or several criteria that are included in the number of quality indicators.

Relativity of the optimum.

In connection with the above, the concept of an optimal solution is not an absolute category; it is valid only under the conditions determined when setting the optimization problem. First of all, choice optimal option depends significantly on what is accepted as the optimum criterion and restrictions.

It should be obvious that if, when optimizing an engine with a given system of restrictions, the optimum criterion is taken as effective power, then we will get one set of optimal design parameters, if the engine is optimized by specific fuel consumption, another, and, finally, if the engine is optimized by traction properties , - third.

Let's give an example. Let’s say that when setting up the problem of optimizing a diesel engine of a given power, the assigned limit value of the resource to major renovation R= 5000 h. It is likely that as a result of the engine optimization operation we will have a high-speed engine design. If, other things being equal, we set the value of the limiting resource R= 100,000 h, then we will obtain an optimal low-speed engine or we will find that the problem posed has no solution (if there is a limitation on the dimensions and weight of the engine).

In multicriteria problems, the results of choosing an optimal solution depend even more on the formulation of the problem, since it is necessary to additionally specify a rule for choosing optimal solutions - the principle of optimum.

From the above it follows that any optimization is relative, and, using the term “ optimal system", it is necessary to determine under what conditions the optimum is ensured.

Model classification.

Modelingis a powerful means of scientific and technical knowledge, during which it is not the object itself that is studied, but some intermediate system (natural or artificial) capable of providing information about the cognizable object in the aspect necessary for the researcher based on the tasks that face him .

Modeling has become so deeply embedded in technology that we often do not notice that we are dealing with models. Currently, any technical object, before it is embodied in metal, goes through stages, so to speak, of model existence in the form of:

drawings, calculations, mock-ups, pilot installations, etc.

And in fact, it is not the object itself that is designed, but its models, which are then, after appropriate transformations, implemented in the form of an object.

We will understand by the model of a technical system A its description, compiled in any language, or other technical system IN, capable of replacing the system A in one aspect or another during its design, research or management.

Any system can be modeled in an infinite number of ways. This set is defined and limited

firstly, the goals of the system,

secondly, the purposes of modeling,

thirdly, technical means for constructing models, and, finally, creative abilities their creators who are located.

Using models is convenient for many reasons:

1) the model is easier to handle;

2) most often we can know more about the model than about the original;

3) the model allows you to get an idea of the extreme situations in which the system may find itself, without danger to equipment or human life;

4) the model is usually much cheaper than the original, and its use saves time.

Today we can definitely say that systematic approach impossible without the widespread use of modeling. Models are mainly necessary to perform such work as studying the laws of functioning of systems, taking into account their relationships with the external environment;

predicting the behavior of systems or their properties in given situations and predicting situations of interest;

selection and optimization of parameters and characteristics of systems operation;

management of design, production and operation of systems.

Research problems that can be solved using modeling can be divided into four groups:

direct problems of analysis, in which the reaction of a system with a given structure and properties to an action on it is determined;

inverse problems of analysis, in which, based on a known reaction of a system with a known structure and properties, the disturbances that caused this reaction are determined;

synthesis problems, requiring finding the structure of the system and its parameters that provide the specified properties;

inductive problems, the solutions of which are necessary to test hypotheses, clarify descriptions of the system, and identify certain properties of the system.

All models can be divided into abstract and material. Abstract we will call models that are descriptions, and models implemented in the form of technical, cybernetic or combined systems,- material .

Abstract models are information systems; they cannot exist without material storage media. Among the abstract models we can distinguish: verbal models (for example, descriptions of engine design, operating instructions), graphical models (drawing) and, finally, mathematical models that primarily use languages of mathematical symbols for description purposes.

On the other hand, there are abstract models of systems and abstract models of operations on systems. We will call the latter operating models, they serve to perform various operations performed on both abstract and material models.

An operation on a model can be considered the model itself, if the operating model is presented as a model of the functioning of a complex supersystem, which includes the system on which the operation is performed and the system that performs the operation, - a person, a computer or a human-machine system.

Material models are divided into physical and analog.

Physical modelshave the same physical nature of processes as the system being modeled . IN analog models real processes that take place in the simulated system are replaced by processes of a different physical nature, which have common patterns with real processes .

The concept of technical systems, the laws of structure and development of technical systems

As noted in paragraph 1.2, the concepts of “technology” and “technique” are not identical: technology is only one of the means of implementing technology. Following the same logic, it is necessary to distinguish between technological and technical systems, and, therefore, to know the differences in the patterns of their formation and development.

Technical system includes a spatial collection of interconnected elements that form something whole, intended to perform one or more

functions necessary either directly for humans or other technical devices.

It is obvious that the technical system is a material system. It can be studied and improved by purposefully modifying its constituent elements. The most important constituent elements of any technical system are: a working element (actuator), an energy source (drive), a transmission (transmission mechanism) and a control element.

It is also obvious that technical systems performing the same function may, nevertheless, differ from each other in the principle of their operation, and, therefore, in their constituent elements.

The idea of the need for a technical system is realized through the principle of operation, which ensures the possibility of its functioning with the help of the corresponding working body - the primary element of any system, under which all other elements are selected. In turn, a suitable operating principle is selected from the known laws of nature.

Thus, the purposeful creation of a new technical system goes through the following stages: human (society) need - the emergence of an idea - the search for relevant knowledge - the determination of the operating principle of the system - the choice of a working body - the selection of other elements of the system.

The system will be operational if all four organs are minimally efficient. Increasing the performance (functionality) of the system occurs through the improvement of all its organs. This improvement occurs unevenly - first one, then another element in its development breaks forward and forces the rest to improve. But a period comes when everything possible has been squeezed out of the reserves of all elements and there is nothing and nowhere to improve further - the system has exhausted its capabilities. It either dies (for example, a quill pen as a writing medium, a torch), or stops in its development (pencil, incandescent lamp), or its working organ enters new system(the lead of a regular pencil - into a collet pencil).

Thus, the history of the development of a technical system can be represented in the form of a diagram consisting of a long chain of successive systems with different operating principles, subsystems, supersystems, and connections between them. This scheme is called a “system operator”, since it allows one to navigate the entire genetics of the system, or a “multi-screen thinking scheme”.

The more "screens" the human mind can see than more connections establish and take into account, the easier it is to accept the objectivity of the laws of development of technical systems.

Currently, the following laws of the structure and development of technology have been formulated:

Laws of structure:

1. The law of correspondence between function and structure.

The essence of this law is that in a properly designed technical system, each element - from complex units to simple parts - has a very specific function (purpose) to ensure the operation of this system. Thus, properly designed technical systems have no unnecessary parts.

The use of the law is most effective when searching for more rational and effective design and technological solutions for new technical systems.

2. Law of correlation of parameters of a homogeneous series of equipment
ical systems.

The homogeneous series includes those technical systems that have the same function, structure, operating conditions (in the sense of interaction with objects of labor and the environment) and differ only in the values of the main parameter (for example, size).

3. Law of symmetry of technical systems.
A technical system exposed to environmental influences

in the form of flows of matter, energy or information, must have a certain type of symmetry.

4. Law of homological series.

The law of homological series (from gr. homologos- corresponding, similar) in hereditary variability was formulated by N.I. Vavilov, who established parallelism in the variability of related groups of plants. Later it was discovered that the basis of this phenomenon is the homology of genes (their identical molecular structure and similarity in the order of arrangement in chromosomes) in related species.

When genetically analyzing artificial objects, they can be compared with objects of living nature, each of which has also reached a very high level of development and is perfect in its own way. The fundamental difference between them is that the evolution of living things - from the simplest amoeba to the most complex protein organisms - occurred under natural conditions of their interaction with the external environment as a struggle for survival. And each stage of this improvement is also a resolution of a contradiction, but one that arose, for example, in connection with

Zi with a sharp change in temperature or the disappearance of a species that served as the traditional food of another, etc.

Thus, the law of homological series makes it possible to quite accurately predict the emergence of new technical solutions.

Laws of development:

1. The law of progressive evolution of technology.

The action of the law of progressive evolution in the world of technology is similar to the action of Darwin's law of natural selection in living nature. Its essence is that in a technical object with the same function, each transition from generation to generation is caused by the elimination of the main defect(s) that have arisen, associated with the improvement of any criterion (indicator) of development in the presence of certain technical and economic conditions. If we consider all transitions from generation to generation, i.e. the entire history of the constructive evolution of a certain class of technology, then one can observe patterns of exhaustion of the possibilities of design and technological solutions at three levels.

At the first level, individual parameters of the technical solution used are improved. When changing the parameters no longer gives a significant effect, changes are made at the second level - by moving to a more effective technical solution, but without changing the physical principle of operation. Cycles at the first and second levels are completed until, within the framework of the operating principle used, possible new technical solutions that provide improvement in the indicators of interest are exhausted. After this, a revolutionary change occurs at the third level - a transition to a new, more progressive principle of operation, etc.

In the law of progressive evolution, the exhaustion of the functionality and efficiency of a design is not just a formality: until optimal parameters are achieved, a transition to a new technical solution or to a new operating principle cannot occur.

The pattern of exhaustion operates only under certain conditions: if, in the presence of the necessary scientific and technical potential, the transition to a new technical solution or physical operating principle provides additional efficiency that exceeds the costs, then a leap to a new technical solution or physical operating principle can occur without exhausting the capabilities of the previous ones.

2. The law of staged development of technical systems. Any technical system in its development goes through four main stages:

1) the technical system implements only the function of processing the object of labor (technological function);

2) along with the technological system, the technical system implements the function of providing the process with energy (energy function);

3) the technical system, in addition to the technological and energy ones, implements the function of process control;

4) the technical system, in addition to all previous functions, also implements the planning function, excluding humans from the technological process.

The transition to the next stage occurs when a person’s natural capabilities in improving the performance of a fundamental function - meeting the needs of society - have been exhausted. An example of the staged development of technical systems is given in Table. 5.1.

Table 5.1

Staged development of technical systems

Main function of the technical system	Technological function (TF)	TF + energy function (EF)	TF + EF + + control function (FU)	TF + EF + + FU + planning function
Grinding grain	Manual stone millstones	Stone millstones driven by a water wheel or steam engine	Mill with system automatic control(self-propelled guns)	A mill with self-propelled guns receiving a task from automated system work planning
Movement on the water surface	Ship with oars (muscle drive)	Ship with a sail (movement by wind power)	Steamboat (movement by steam energy with the ability to control)	Modern ship with computerized navigation system

3. The law of expansion of the set of needs-functions. If there is the necessary potential and socio-economic feasibility, the new need that has arisen is satisfied with the help of technical systems created for the first time; in this case, a new function arises, which exists as long as its implementation ensures an improvement in the life of everyone.

4. The law of increasing diversity of technical systems.

The variety of technical systems in the world, country or industry, as well as a separate class of technical systems that have the same function, due to the need to most fully satisfy human needs, ensure high rates of labor productivity and improve other criteria for the progressive development of technology, monotonically and rapidly increases over time. Number of new technical systems over a period of time t(N(t)) increases exponentially

5. Law of increasing complexity technical objects.

The complexity of technical objects with the same function, due to the influence of factors of the staged development of technology and the progressive constructive evolution of technical systems, increases monotonically and rapidly from generation to generation.

To summarize the above, let us formulate postulate theories for solving inventive problems: technical systems develop according to objectively existing laws: these laws are knowable, they can be identified and used for the conscious development of technical systems, which occurs in a direction common to all systems: increasing the level of their ideality.

A methodology for modeling object models of complex technical systems has been developed. The methodology is based on the classification of technical systems. The existing classification systems by type and composition of technical systems are considered. It is concluded that existing classification systems are not enough to build a methodology for modeling complex technical systems. A classification of technical systems according to the structure of its elements is proposed, including three types of structures: park, network and linear. The methodology for constructing an object model of technical systems that have network and linear structure. The methodology for constructing object models makes it possible to take into account the features of the operating infrastructure of a technical system, the interconnection of complexes of technical systems, as well as the structure of the equipment that is used in complexes of technical systems.

technical system

classification of technical systems

technical system structure

1. GOST 27.001-95 System of standards “Reliability in technology”.

2. Kirillov N.P. Class characteristics and definition of the concept of “technical systems” // Aerospace instrumentation. – 2009. – No. 8.

3. OK 005-93 All-Russian product classifier.

4. PR 50.1.019-2000 Basic provisions of a unified system of classification and coding of technical, economic and social information and unified documentation systems in the Russian Federation.

5. Khubka V. Theory of technical systems. – M.: Mir, 1987. – 202 p.

In the tasks of designing automation systems for managing organizational and technical systems (OTS), an important place is occupied by the task of modeling the technical part of such systems. The variety of types of technical components of the GTS and the complexity of its structure require the development of general approaches to modeling technical systems.

The formulation of the term technical system (TS) depends on the task at hand. The basic element of OTS control automation systems is the information environment, which contains information about the structure of the technical system. Therefore, when modeling technical systems to solve OTS automation problems, we can limit ourselves to by the following definition: “A technical system is an interconnected set of technical objects designed to perform certain functions.” Here, a technical object is any product (element, device, subsystem, functional unit or system) that can be considered separately.

Classification of technical systems

It is advisable to subordinate the development of models of technical systems to a set of rules, which will streamline the process of creating a model and improve the quality of modeling. The most important of these rules is the use of classification of technical systems as the basis for constructing a model of a technical system. The presence of a classification of technical systems makes it possible to identify the type of structure of a complex technical system, which makes it possible to decompose the system in accordance with the standard structure.

Classification in terms of the composition of technical systems

Let us consider the existing classification systems for technical systems. All technical objects that are produced at enterprises have classification characteristics in accordance with the Unified System of Classification and Coding of Technical, Economic and Social Information (ESKK). The main purpose of classification in the ESKK system is to organize information about objects, which ensures the sharing of this information by various subjects. From the classifiers presented in the ESKK for the task of modeling technical systems highest value has an all-Russian product classifier (OKP), which contains a list of codes and names of hierarchically classified groups of product types.

For the task of modeling the structure of a technical system, the greatest interest is the classification according to the level of complexity of the technical system. The following difficulty levels are distinguished:

I. Structural element, machine part.

II. Knot, mechanism.

III. Machine, device, apparatus.

IV. Installation, enterprise, industrial complex.

When developing a classification of technical systems, it is necessary to take into account the principles of dividing products into parts, which are adopted in the Unified System of Design Documentation. GOST 2.101-68 “Types of Products” defines a product as an item or set of items manufactured at an enterprise, and divides products into the following types:

Parts are products that do not have component parts.
Assembly units are products consisting of several parts.
Complexes are two or more products designed to perform interrelated operational functions.

Comparing classifications by level of complexity and by type of product, the following conclusions can be drawn:

Both classifications single out a part as the simplest object.
Concept assembly unit corresponds to both the concept of a node and the concept of a machine (device, apparatus).
The concepts of an industrial complex (installation) and a complex as a type of product reflect the same property - the combination of parts into a single whole.

Combining the classification by level of complexity, types of products and types of products, we introduce the following elements of classification according to the composition of the technical system:

A technical system is a set of technical objects that perform a specific function corresponding to the purpose of its creation.
Equipment is a product that represents a product.
A unit is a part of a product assembled according to an assembly drawing.
Part - a piece of equipment or assembly, made of a homogeneous material, manufactured according to a detailed drawing.
Equipment complex - two or more equipment designed to perform common functions.

A unit and a part are elements of equipment, and a complex is a combination of equipment. The combination of equipment into complexes can be divided into combination levels - a complex of the upper, middle and lower levels.

Rice. 1. Hierarchical structure of the technical system

Classification from the point of view of the structure of the technical system

Technical system as component organizational and technical system can be attributed to one of the following structural concepts:

List (park) structure of homogeneous objects, between which there is no interaction. Each object performs its own function.
The network structure of a technical system is a set of technical objects between which there is interaction. For this type of structure, it is necessary to describe not only the technical objects themselves, but also a description of the elements utility network, through which technical objects interact;
Structure of a linear technical system.

Examples of a park structure are a vehicle fleet or an enterprise equipment park. An example of a network structure is a city heat supply system, including a central thermal station(DH), a set of thermal points (TP) and heating networks for transferring coolant from the central heating system to the transformer substations and from them to residential buildings.

An example of the structure of a linear technical system is railway track, which is formed by a number of local and linear engineering structures - the upper structure of the track, consisting of rails, sleepers, fastenings and ballast, and artificial structures.

The network structure of a technical system differs from a park structure in the presence of a network component that ensures the interconnection of elements. This allows us to consider the park structure as a special case of a network structure.

Modeling the structure of technical systems

The task of modeling the structure of a technical system is to display the structural properties of a technical system and describe its individual subsystems and elements. Depending on the goals of the automation project, the same technical system will be presented different models. The difference between models of a technical system will be in the completeness and detail of the description of the structural properties of the technical system. The completeness of the vehicle description is determined by that part of the complex of technical objects that will be taken into account in the vehicle model. The detail of the vehicle description is determined by the level of hierarchy up to which the elements of the vehicle will be taken into account.

Object model of a technical system

The basic model of a technical system is its object model. The object model of the technical system reflects its structure and must answer the question: “What parts does each element of the technical system consist of?” The use of the principle of dividing the whole into parts determines the hierarchical nature of the object model of a technical system.

Let's consider the problems of constructing an object model for a network and linear technical system.

Object model of a network technical system

The construction of the object model is based on the analysis of the following technical documentation:

Layout of technical system complexes and explanations for it.
Operational documentation for each type of equipment used in the technical system.
Technical documentation to the network complex.

The layout diagram allows you to determine the position of the elements of the technical system in relation to the elements of the infrastructure for the functioning of the technical system. For a technical system located within the city, the position of objects is indicated in relation to streets and houses. For a technical system located on industrial enterprise, the position of objects is indicated in relation to the workshop number and the cell number in this workshop, which are formed by supporting columns. Other methods can be used to indicate the position of objects in relation to the elements of the vehicle operating infrastructure. The layout diagram indicates the complexes of the technical system, network elements that ensure the interaction of the complexes and elements of the infrastructure for the functioning of the technical system. An example of the layout is given in Fig. 2. The diagram shows a technical system consisting of 4 sets of technical means (CTS 1, 2, 3, 4), and a physical network that unites the CTS into a single system. The grid (A, B, C, D; 1, 2, 3, 4) serves to position the elements of the technical system in the system of functioning of the technical system.

Based on the analysis of the technical system level model, it is necessary to highlight:

Types of technical system complexes.
Types of engineering network elements.

The types of complexes of technical systems are determined by the criterion of the same internal structure. For each type of technical system complex, it is necessary to build its own model, which displays the lower-level technical system complexes and the types of equipment that are used in this complex.

Rice. 2. Layout of technical system complexes

Rice. 3. Object model of the technical system complex

Since each type of equipment has its own internal structure, for each type of equipment it is necessary to build its own model, in which this equipment is divided into components and parts.

The final stage of developing a model of a network technical system is the development of a model of utility networks. At the stage of analyzing the layout of the technical system and its explanation, it is necessary to identify the types of technical objects that are used to build the engineering network of the vehicle. Let's consider a utility network model using the example of a pipeline network, the main elements of which are presented in the diagram.

A distinctive feature of the pipeline network is that some of its elements (pipes, connecting elements) are manufactured according to wiring diagram, and the part (fittings) is a certain type of equipment. However, in most cases, it is not necessary to develop a model of the internal structure of the reinforcement.

Rice. 4. Equipment object model

Rice. 5. Object model of the network structure of a technical system

Object model of a linear technical system

A feature of a linear technical system is the use of technical objects to form infrastructure. Let's consider the problems of creating an object model of a distributed technical system using the example of a railway track.

A railway track is a complex complex of linear and concentrated engineering structures and facilities located in the right-of-way. The main element of the railway track is the rail track, which is formed from rails, sleepers, fastenings and other elements that together make up the upper structure of the track. The superstructure of the track is laid on the roadbed. At the intersection of the railway track with rivers, ravines and other obstacles, the upper structure of the track is laid on artificial structures. TO important devices railway tracks include turnouts, since the entire complex structure of railway tracks is based on their separation (connection), which occurs in a turnout.

A technical system is a set of railway tracks that represent a single whole - the infrastructure part railway as an integral part of the organizational and technical system. In fact, in addition to the railway track, the infrastructure part of the railway also includes power generation, signaling and communication devices. However, the structure-forming element of the railway infrastructure is the railway track.

From a geometric point of view, a railway track is a network consisting of nodes and arcs. Arcs are sections of the railway track between two nodes. Nodes are objects connecting several sections of a railway track.

A railway track layout is a collection of nodes and arcs, each of which has a unique name.

Rice. 6. Layout of linear technical system objects

To represent the elements of a linear technical system, it is necessary to present the hierarchical structure of objects that together form this system. If we limit ourselves only to the main elements, then the model of the infrastructure part of the railway can be presented in the following diagram (Fig. 7).

Rice. 7. Model of railway objects

Rails, sleepers, fastenings are products (parts) that are assembled at specialized enterprises into technological complexes, which are then laid into the railway track. Such complexes can be: a rail and sleeper grid, in which two rails and the required number of sleepers are connected using fastenings; rail string - several rails welded together. Elements of turnouts are also manufactured at enterprises as parts and assembled into a single technical object at the installation site. Artificial structures are complex engineering structures, which are built according to special projects. A model of an artificial structure is developed according to the same rules as a model of equipment.

Conclusion

Technical systems often have complex structure, which requires a structural approach to their modeling. Modeling of technical systems should be based on the typification of technical systems and on the analysis of the structural properties of both the technical system as a whole and its individual elements. The central element of the technical system model is equipment as a product that is produced at the enterprise.

Reviewers:

Panov A.Yu., Doctor of Technical Sciences, Head of the Department of Theoretical and Applied Mechanics, Federal State Budgetary Educational Institution of Higher Professional Education "Nizhny Novgorod State technical university them. R.E. Alekseeva", Nizhny Novgorod;

Fedosenko Yu.S., Doctor of Technical Sciences, Professor, Head of the Department of Computer Science, Control Systems and Telecommunications, Volzhskaya state academy water transport", Nizhny Novgorod.

The work was received by the editor on July 28, 2014.

Bibliographic link

Zaporozhtsev A.V. MODELING OF TECHNICAL SYSTEMS // Basic Research. – 2014. – No. 8-6. – pp. 1288-1294;
URL: http://fundamental-research.ru/ru/article/view?id=34755 (access date: 03/04/2019). We bring to your attention magazines published by the publishing house "Academy of Natural Sciences"

A technical object is a truly existing device, method, or material created by man and designed to satisfy certain needs.

All technical objects consist of elements that are indivisible parts of the whole. If the functioning of one element of a technical object affects the functioning of another element, then such technical objects (as opposed to units) are usually called technical systems (TS).

A technical system is a set of interconnected elements of a technical object, combined to perform a specific function, while possessing properties that cannot be reduced to the sum of the properties of individual elements.

Types of technical systems.

The elements that form a technical system are only relatively indivisible parts of the whole. For example, a woodworking machine includes many complex parts: a frame, main movement, feeding, basing, adjustment, adjustment, control and drive mechanisms. At the same time, in a “woodworking shop” system with a large number of different machines, a separate machine can be considered an element, that is, an indivisible whole. In this regard, in relation to the “machine” system, the “woodworking shop” is called supersystem, and the above listed parts of the machine are subsystems. For any system, a subsystem and a supersystem can be distinguished. For the system “mechanism of the main movement of the machine,” parts of the bearing housing, shaft, and cutting tool will be subsystems, and the machine will be a supersystem. Some systems perform opposite functions in relation to a given system. They are called antisystems. For example, a surface ship and a submarine, an engine and a brake, are objects that function in reverse.

The ideal of technical systems.

Technical systems develop according to the law of progressive evolution. This means that in the system of each generation, development criteria are improved until they approach the global extremum. Each technical system strives for its ideal when its parameters of weight, volume, area, etc. are approaching extremes. An ideal technical system is one that does not seem to exist, and its functions are performed in full on their own. The ideality law is valuable because it suggests in which direction an effective technical system should develop. It is generally accepted that a system is ideal if it has one or more of following properties:

1. The dimensions of the system approach or coincide with the dimensions of the object being processed or transported, and the mass of the system is much less than the mass of the object. For example, in ancient times bulk materials were stored and transported in clay vessels, now in bags.

2. The mass and dimensions of a technical system or its main functional elements must approach zero, and in the extreme case they are equal to zero when there is no device, but the required function is performed. For example, dividing wood into parts is done with a saw. But now laser systems have appeared for these purposes. Cutting tool as if not, but its functions are performed.

3. The processing time of an object tends to or equals zero (the result is obtained immediately or instantly). The main way to realize this property is to intensify processes, reduce the number of operations, and combine them in space and time.

4. The efficiency of an ideal system tends to unity, and energy consumption tends to zero.

5. All parts of an ideal system perform without downtime useful work to the full extent of its calculation capabilities.

6. The system operates indefinitely without downtime or repairs.

7. The system operates without human intervention.

8. An ideal system does not provide harmful influence on people and the environment

The scope of technical systems is very wide and includes all sectors of the economy. In table 3.1 provides examples of technical systems used in the most important industries economy.

Classification of technical systems according to various defining characteristics brings a fairly harmonious order to their vast variety and allows for better orientation. As a consequence of this, it becomes possible to study best practices, which sometimes makes it possible to discover interesting, hitherto hidden relationships between rather distant technical systems.

Technical systems can be classified according to the following signs:

by function (working action) eg technical systems for fixing, shaping, rotating, lifting;

Table 3.1

Examples of technical systems in various industries economy

Branch of the economy	Technical system
appointment	car
Mining	Mining Transportation Enrichment	Shearer Conveyor Sorting machine
Energy	Steam generation Electricity generation	Steam boiler, drum Steam turbine, hydraulic turbine, generator
Metallurgy	Iron production Steel production Rolled steel production	Blast furnace Open hearth furnace Rolling mill
Chemical industry	Petroleum refining and refining Dyes production Plastics production	Reservoir Reactor Column
Pharmaceutical industry	Medicine production	Press, calender
Metalworking industry	Pressure processing Cutting Heat treatment Casting Assembly	Press, hammer Machine Oven Forming machine Conveyor
Construction industry	Construction of bases and foundations Construction of above-ground structures Earthworks Hydraulic construction Production of building materials	Excavator Crane Scraper Concrete Mixer Molding Press
Transport	Rail transport Shipping Air transport	Locomotive, carriage Steamboat Airplane
Textile industry	Textile production Ready-made dress production	Spinning machine, loom Sewing machine
Food industry	Flour production Edible fat production Milk processing	Flour Mill Press Centrifuge
Medicine	Diagnostics Therapy	X-ray machine Prosthesis
Printing and office work	Printing Office needs	Printing machine Typewriter, calculating machine
Rural and forestry	Land cultivation Harvesting Timber harvesting	Tractor with plow Combine harvester Electric saw
Distribution, trade	Self-service Packaging	Inspection machine Packaging machine

by transformation type, for example, technical systems for converting matter, energy, information, biological objects;

according to the principle of working action, for example, technical systems based on mechanical, hydraulic, pneumatic, electronic, chemical, optical, acoustic principles;

by nature of functioning, for example, power, speed, pulse technical systems, systems for various conditions environment(for example, for tropical climates), etc.;

by difficulty level, for example, structural elements, components, machines, enterprises as a whole;

by manufacturing method, for example, technical systems made by casting, forging, stamping, turning;

according to the degree of design complexity;

according to form, for example, technical systems (structural elements) in the form of a body of rotation, flat, complex shape;

according to material, for example, technical systems made of steel, copper, plastic;

according to the degree of originality of the design, for example, borrowed, modified, modified, original technical systems;

by type of production, for example, technical systems manufactured under single, serial or mass production conditions;

by manufacturer's name, for example, technical systems "Siemens", "Fiat", "VAZ", "BOSCH";

according to place in the technical process, By operational properties, appearance, technical and economic characteristics, etc.

It is clear that the same technical system can simultaneously belong to several classes. Below we will consider in more detail those principles of classification of technical systems that, from the point of view of the designer and constructor, are especially important.

Classification of technical systems by function. The names of technical systems are often chosen according to their function. The compilation of product ranges in relation to the requirements of sales, planning, control, comparative assessment, etc. is also carried out, as a rule, in accordance with the function of technical systems. Products are also designated by function in cases where it is necessary to help a potential consumer find this or that technical means to perform a specific function: trade and industrial catalogs, overview tables, etc. serve this purpose.

Any enterprise uses many elements and assemblies that perform one specific function in various branches of technology, such as fasteners, gearboxes, couplings, measuring, regulating and signaling devices, hydraulic and pneumatic devices and their parts, specialized electrical devices, etc. p. Machine units and parts can also be considered as technical systems, so it is advisable to classify them also by function, since the designer, manufacturer and operator use various parts according to their functional suitability. This classification is called constructive and functional , along with classification by manufacturing method, it is the main one when borrowing existing technical systems, unification, typification and standardization of elements and groups. Classification according to these principles allows you to save working hours designer.

Classification of technical systems according to their operating principle. It is important for the designer that technical systems that perform the same functions are further grouped according to some other important characteristic. This sign can be considered operating principle of the technical system. So, for example, technical systems “engines” can be divided according to the principle of operation: electric, internal combustion, external combustion engines. Internal combustion engines, in turn, can be divided according to the physical principle of mixture formation used into carburetor and diesel engines. These kinds of features of technical systems belong primarily to the group of functionally determined properties that are very characteristic of technical systems and are of great importance for the methodological work of the designer.

Classification of technical systems by level of complexity. Dividing technical systems into classes according to their structure is a common occurrence in the work of a designer. The main feature by which classes are formed should be the function of the system. However, given the needs of production, for example, for installation reasons, sometimes it becomes necessary to carry out a different classification. Table 3.2 gives a general idea of the classification of technical systems by level of complexity.

Table 3.2

Classification of technical systems by level of complexity

Difficulty level	Technical system	Characteristic	Examples
I	Structural element Machine part	Elementary system manufactured without installation operations	Bolt, bearing bushing, spring, washer
II	Subgroup Group Node Mechanism	Simple system, performing a simple function	Gearbox, hydraulic drive, spindle head of lathe
III	Machine Device Apparatus	A system consisting of groups and elements and performing a specific function	Lathe, car, electric motor
IV	Installation Enterprise Industrial complex	A complex system consisting of machines, groups and elements, performing a number of functions and characterizing ordered collections of functions and places	Technological line, workshop heat treatment, petrochemical complex

At higher difficulty levels, intermediate levels can also be distinguished. However, it should be remembered that we are talking about a relative hierarchy. The same lower-level system, such as an electric motor or gearbox, is considered as a subgroup in one system, and as a group or machine (subsystem) in another system.

In practice, it is generally accepted that the lower levels of technical systems find more universal application, for example, elements such as “screw”, “bolt”, “nut” are used everywhere in mechanical engineering, “electric motor” quite often, and “ technological line" is used only in certain, special processes.

Classification of technical systems by level of complexity is of no small importance for the designer, since the level of complexity of the technical system

a) is in a certain relationship with the degree of complexity of solving the problem assigned to the designer;

b) involves the establishment of known boundaries for the specialization of the designer (for example, a design engineer deals with an enterprise, a design engineer deals with a machine, a parts designer deals with machine elements);

c) helps the designer navigate the work process, because if he solves a problem at a certain level of complexity, it is important for him to know only how his task is coordinated with a higher level (in relation to a lower level, the designer most often makes only fundamental decisions ).

Based on the assembly drawing, individual levels of complexity can be considered in the same way as collections of manufacturing and installation processes. The formation of appropriate aggregates, primarily from parts, subgroups and groups, is a necessary condition creation of modular structures, as well as expedient organization production process.

Classification of technical systems by manufacturing method. For the manufacture of certain groups of technical systems, the same type is required technological equipment. For example, steam boilers and chemical tanks can be manufactured on the same equipment, while lathes, milling, drilling and other machines can be manufactured on another. Machine parts can also be grouped into technological groups based on the similarity of technological manufacturing operations, where the main distinguishing feature will be the shape. This classification makes it possible to rationally carry out technological preparation of production and increase the efficiency of the production process, since it makes it possible to combine jobs for the production of parts with the same manufacturing method. This, in turn, facilitates the implementation of a variety of rationalization measures, for example, the specialization of workshops and enterprises. The importance of such a classification is especially great when developing and implementing production preparation plans, management and planning methods. It is an integral part of the so-called group processing technology.

Classification of technical systems according to the degree of design complexity. Technical systems can also be classified in terms of design complexity. As an example in table. 3.3 technical systems of the third level of complexity (see Table 3.2) are divided into 6 categories according to the degree of their design complexity. Depending on the level of complexity of the technical system under consideration, an appropriate specialist or group of specialists is selected to solve the problems associated with it. When planning design work, the degree of structural complexity of the technical system being developed serves as a criterion for setting a certain time frame for engineering work.

Table 3.3

Examples of classification of technical systems of the III level of complexity according to

degree of design complexity

Machine parts can also be classified according to the degree of complexity of their design. A corresponding example of classification according to a different principle is given in Table. 3.4. The criteria for assessing the degree of structural complexity are:

a) the degree of originality of the design;

b) the complexity of the functions performed, forms, structure as a whole;

c) complexity of calculations;

d) dimensions, required accuracy of their execution and quality of processing;

d) special requirements requirements for such characteristics as weight, manufacturability of design, costs, appearance requirements, etc.

Table 3.4

Examples of classification of machine parts according to the degree of design complexity

Degree of design complexity	Characteristic	Examples
	Very simple parts with a small number of control dimensions of low accuracy	Support washer, simple lever, small shaft, bolt, mounting bracket
	Simple parts with lots of reference dimensions	Lever, pulley, simple stamping
	More complex parts	Gear, spline shaft
	More complex parts with more reference dimensions	Quite complex castings, small forgings
	Very complex parts	Complex castings of casings and medium-sized forgings
	Very complex and large parts	Frames, machine covers, welded or cast frames
	Particularly complex parts large sizes and unusual shapes with precise adherence to a large number of control dimensions	Turbine blades, large forgings, precision castings with complex shapes

Classification of elements of technical systems according to the degree of standardization and origin. This classification is very important for assessing the cost-effectiveness of the design. By the degree of standardization of a technical system, one can judge the feasibility and possible scale of its production within a given enterprise. From an economic point of view, the number of original structural elements in the technical system should be as small as possible, since they characterize the requirements for design and technological preparation of production. There is a rule that says that the less the number of original structural elements in the created system, the higher the likelihood of organizing its serial or even mass production. Often, however, due to some other reasons, these considerations are not decisive.

Classification of technical systems according to the degree of originality of the design. When developing a new machine, the designer always tries to use components and parts that have proven themselves in practice. According to the degree of originality of the design, technical systems can be divided into the following categories.

Borrowed technical systems. To perform the required function, some technical system or even several systems already exist, from which the most suitable ones can be selected. These primarily include standardized elements and groups (bolts, wedges, valves, springs), as well as non-standardized elements and groups that can be borrowed from other structures.

Improved technical systems. There is a technical system that performs the necessary function, but does not meet certain requirements. There is a need, for example, to change dimensions, power, speed, speed, installation dimensions, material or technology. The structures of the system and the most important properties of the elements in this case remain unchanged. Thus, modification of the technical system is carried out solely for the purpose of adapting it to special conditions and requirements new task, and new materials are used only to improve quality, reduce cost or modernize.

Modified technical systems. Existing systems do not meet the requirements for some properties of groups and structural elements. In a modified design, usually only the function, some parameters and, if possible, the principle of operation do not change. Elements can be changed in shape, size, material or technology; in complex technical systems, the organ structure and structural design change, i.e. some elements and groups, their connection and placement in space. Usually modification is carried out by redesigning the structure.

New technical systems. There is no technical system to perform the desired function, or the existing one has fundamental deficiencies. A system with a new operating principle and other technical properties is needed.

Classification of technical systems by type of production. The type of production, which is determined by the number of units produced, gives each product a number of characteristic technical and economic properties.

Single production technical systems. In this case, design and preparatory work it is necessary to adapt to the needs of piece production, in which the cost of each manufactured technical system increases. It is possible that in the conditions of a single production the required function of a technical system will not be achieved at all, since in the manufacture of large technical systems one has to work without a prototype. That is why this category of systems presents high demands to the designer.

Technical systems for serial or mass production. These systems are generally better designed from a production standpoint. Due to the large volume of product batches, the share of design costs in relation to total costs is small. However, since, as a rule, only a small part of the products is subject to control, various errors and defects cannot be excluded. Only through continuous monitoring of all operations or manufactured parts and products as a whole can stable quality be achieved in serial and mass production. The above-mentioned categories of systems are also interesting to a specialist in the sense that they form the basis for determining the possible quality of products. There is a clear trend towards an increasing use of unified, mass-produced technical systems, especially for performing various low-level functions, for example elements of connection, measurement, control, drive, distribution. On the other hand, the number of special-purpose technical systems is increasing. Modern production cannot do without a number of auxiliary means, specialized machines, automatic machines and production lines, special equipment, i.e., without everything that ensures the production of cheap standardized products in mass quantities. Both product categories place high demands on the scope and quality of design work.

The classification of technical systems can be carried out from various points of view; at the same time, from the entire set of technical systems, subsets are formed, connected by common distinctive features. The resulting categories can serve various purposes, such as systematization, visibility, evaluation, analysis, etc.