SU714355A1 - Controllable drive - Google Patents

Description

The invention relates to automatic control systems and can be used to create systems with vibration linearization.

A controlled drive with vibration linearization is known, comprising a series-connected oscillator, an amplifier and a motor.

The disadvantages of this drive are low accuracy and low efficiency, since in many cases the parameters of the systems vary within fairly wide limits, for example, during the run-in, depending on the load, on environmental conditions (temperature, pressure and etc.). In this case, both the characteristics of the nonlinear part of the system and the linear part can vary. If the frequency and amplitude of the linearized oscillations are fixed, then either due to a decrease in the transmission coefficient of the system at this frequency or an increase in the deadband, the amplitude of the linearizing K (.1lbpium will be insufficient

for linearization and, either due to an increase in the transmission coefficient at this frequency or reduction of the deadband, the amplitude of the linearizing oscillations of the scientific research institute will not be large, which leads to an unproductive expenditure of energy to, with a limited linear range of the amplifier, to reduce the linear control region

control signal. An example of such si-. The operating systems are manipulative devices, which in their own way are designed to work in extreme conditions and in which during operation they are essentially

Menypotts both static and inertial load. Moreover, when using a hydraulic actuator, the amplitude required for linearization of the nonlinearity of the dead zone type is a fairly large amount that can reach up to 30% of the linear zone.

The closest in technical essence to the proposed invention is a controlled drive comprising serially connected amplitude control unit, oscillator, amplifier, motor, vibrometer, filter (module extraction unit and adder, to the corresponding input of which the bias source 23 is connected.

It provides for maintaining a constant value of the amplitude-frequency characteristic of the system by changing the gain of the controller with the help of a self-tuning contour when changing the parameters of an object in a given area. At the same time, the frequency of linearizing oscillations is fixed.

However, with significant nonstationarity of the system parameters. Inevitably, non-linearity of the constraint type always occurs in real systems, which leads to a decrease in the linearity range with respect to the control signal and to a decrease in accuracy. In this case, it is impossible to use the resonant properties of the drive, which could increase the coefficient of the system’s other actions.

The purpose of the invention is to increase the efficiency and accuracy of a controlled drive.

The goal is achieved by the fact that the controlled drive contains a three-position threshold element and a frequency control unit, the output of which is connected to the corresponding input of the oscillator, and the input is connected to the input of the control unit with the amplitude and output of the three-position threshold input, which is connected to the output the adder, and, in addition, the output of the oscillation generator is connected to the control input of the filter.

The controlled drive device is illustrated in FIG. 1 presents a functional controlled drive circuit; in fig. 2. depicts the static characteristic of a three-position threshold element. in fig. 3 shows the equivalent static characteristic of a three-position threshold element, obtained with consideration of the adder and source of displacement; in fig. Figure 4 shows a typical amplitude-response drive characteristic, containing a peak amplitude A at a frequency. .

The device contains an oscillation generator 1, an amplifier 2j engine 3, a vibrometer 4 ,. the filter 5, the allocation unit of module 6, the adder 7, the source of the sweep 8e, the three-position threshold element 9, the amplitude control unit 10 and the frequency control unit 11.

The controlled drive operates as follows. The control signal Ua is fed to one of the inputs of the amplifier 2 and is processed by the motor 3 in accordance with the drive law of a closed or open type. The vibration linearization signal from oscillation generator 1 is fed to another input of amplifier 2 and is added to the control signal Ua ,. and causes

5 superimposed oscillations at the output of the engine 3, linearizing the drive. These vibrations are measured by the vibrometer 4 and on the output of the filter 5, whose passband is tuned to the oscillator 1 frequency range, the signal at the linearization frequency is compressed, the amplitude of which is proportional to the vibration of the output shaft of the drive. At the output of the block of the module 5 module (in the particular case of a rectifier), a constant signal is obtained, the level of which is also proportional to the amplitude of oscillations of the output shaft. This signal is transformed in accordance with the equivalent characteristic of the three-position threshold element S, obtained with regard to the adder 7 and the source of the bias 8 (Fig. 3).

Claims (2)

Suppose that for some reason the amplitude of the swing shaft of the output shaft has decreased (has fallen), so that the input signature of the three-postern element of threshold element 9 has become less than the level signal -1 (+1) and its output signal, gene control-. oscillator 1, Produces an increase (decrease) in the amplitude of linearized oscillations until the output signal of the allocation unit of module 6 enters the equivalent Cd zone, characteristics, and O output of the three-position threshold element 9 logical O. The amplitude change stops and frequency control unit 11 goes into frequency change mode. This is done because, in terms of the achievement of a given amplitude, it does not guarantee that the optimum frequency is achieved in terms of the task set. Suppose further that the system has a linearization frequency U.i. 57 (Fig. 4) s or tOg, for one reason or another, shifted relative to the frequency W, at which the drive currently has a peak of the amplitude-frequency characteristic (AFC). When the logical zero at the input of the frequency control unit 11 by its output signal increases, .Ilnvi decreases the frequency of the output oscillator 1} and the output signal of the control unit that 11 is stored in it. The amplitude of the linearizing oscillations at the outlet when the water varies in accordance with its frequency response. At the output of the three-position threshold element 9, a logical signal 1 or +1 appears, which is also stored in the frequency control unit ii. In accordance with the incoming signaling unit, the amplitude control unit 10 switches the oscillation mode to increase mode. or amplitude reduction. As soon as a logical O is detected at the gate of the three-position threshold element 9, the frequency control unit 11 will be controlled by the oscillator 1 control signal in accordance with the memorized values of the control signal at the output of the frequency control unit 11 and the signal from the three-way threshold element In the preceding cycle, the signals stored in the frequency control unit 11, belonging to the previous cycle, are erased by preparing to memorize the signals of the next cycle. If, in the previous cycle, an increase in the frequency of the signal resulted in the output of a fl at the output of the three-position threshold element, then the oscillator switches to the same frequency increase mode. If an increase in frequency resulted in the occurrence of -1, then the oscillator 1 switches to a mode of decreasing frequency. If, in the previous cycle, a decrease in frequency has led to the appearance of -1 at the output of the three-position threshold element 9, then the oscillator. 1 switches to the frequency up mode. If the decrease in frequency leads to the direction of +1, then the oscillation generator 1 switches to the same frequency reduction mode. Thus, a constant frequency search is performed in order to trace the frequency response peak and at the same time 5, 6 live for the minimum allowable amplitude, which is necessary and sufficient for linearizing the drive. The choice of the magnitude of the bias from the bias source 8, the width of the deadband and the hysteresis of the three-position threshold element 9 determines the noise immunity of the drive and the frequency of the search movements of the system. If the frequency of the working and linearizing effects overlap with each other, then to increase the noise immunity of the drive, the filter 5 can be controlled by the oscillator 1 so that its operating frequency is always tuned to the frequency of the linearizing oscillations. In the described controlled drive, it became possible to use the frequency corresponding to the frequency response peak of the frequency response as the linearizing frequency. the amplitude of the signal at the drive output is monitored and maintained at the minimum level. This improves the accuracy of the drive by reducing the deadband and increasing the linear range by a value of the order of 4O-5O% and increases the efficiency by setting a mode in which the optimum drive parameters are used, by 10-15%. Drive, containing a series-connected amplitude control unit, an oscillator, an amplifier, a motor, a vibrometer, a filter, a module allocation unit, and an adder, to the corresponding input of which an offset source, different It is noted that, in order to increase efficiency and accuracy, it contains the ax-position threshold element and the frequency control unit, the output of which is connected to the corresponding input of the oscillator, and the input is connected to the input of the amplitude control unit and the output of the three-position threshold element whose input is connected to the output of the adder. 2. The controlled drive according to claim 1, wherein the output of the oscillator is connected to the control output of the filter.