SU389604A1 - METHOD OF MANAGEMENT OF THE EXECUTIVE MOTOR OF THE FOLLOWING DRIVE WITH LUFF IN MECHANICAL - Google Patents

Description

one

The proposed method for controlling the actuating motor relates to regulating the electric motors IB in dependence on their parameters.

A known method for controlling executive motors of a follower drive with backlash in a mechanical transmission consists in supplying a drive signal to the motor control circuit and a signal to compensate for inertia.

However, the dependence of the duration of the correction signal and the time of selection of the backlash on the magnitude of the input action does not allow for an increase in the control efficiency to apply an increase in the duration of the correction signal. With small input effects, this leads to the appearance of self-oscillations and, ultimately, the instability of the entire follow-up drive.

The invention makes it possible to improve the accuracy and improve the quality of transients of a servo drive with backlash in a mechanical transmission. This is achieved by significantly reducing the dependence of the backlash selection time on the magnitude of the input action.

According to the proposed method, in order to increase the accuracy and improve the quality of the transients (the processes in the MO-transition of the motor speed through zero form two signals: one is proportional in duration to the value of the driving signal, the other to a constant duration determined by the backlash value and inertia of the engine. From of the generated signals to the motor is given the longest in duration and if it is a signal of constant duration, then immediately after it ends, a signal of reverse polarity (phase) is given, the duration which is determined by the value of the input

signal.

The proposed method is illustrated by drawings.

Hai FIG. 1 shows the diagrams of the input and output signals of the executive engine with “small amplitudes of oscillations; in fig. 2 shows diagrams of input and output signals of the executive engine at " large oscillation amplitudes.

In the drawings denoted: L / y control

uncorrected signal; p @ is the rotational speed of the engine (or the signal proportional to it); Ui - correction signal generated during the mismatch of the signs of the master and the output (speed) signals

engine; Uz is a correction signal proportional to the duration of the value of the setting signal; Us is a correction signal of constant duration; U - matching correction signal; fi is the duration of the signal Uc, tz-ti is the duration of the signal Uz, ta-ti is the duration of the signal / 7h; and-ts - signal duration 4-ti - backlash selection time. The motor control signal is supplied by a control sinusoidal signal Uy UM-Sir (j3t, where UM is the amplitude, w is the oscillation frequency. Due to the inertia of the engine, the output signal of the motor is shifted relative to the angle specifying the torque from the time T and oscillation frequency of the driving signal: L o arctg. Therefore, when changing the sign of the driving signal, the motor will still rotate for some time (4 arc tg w G, ,,) in the same "Rule." The play will start only 1 when the rotation speed of the engine control signal, its signal (sign sgn / 0). Therefore, to compensate for the effect of the backlash IB on an automatic system, it is necessary first to shorten the inequality of the input and output oscillations of the engine. To do this, for a specified period of time, the engine is supplied in accordance with the polarity of the control signal t / y the correction signal t / i of constant amplitude L / C. and - sign and y with sign Well sign p9 f / i: O with sign Uy - sign pb At this time there is a forced deceleration of the engine, resulting in the Inequality interval decreases (interval ti in FIG. 1 and 2). As soon as the signs of the output and input oscillations of the engine coincide, a control signal must be given to the control circuit, which would force the backlash selection without causing excessive overshoot in the system. This is solved as follows. The backlash 2b is considered as a jump-like effect on the system with amplitude 2b. In order to obtain a transient process that is close to IK of optimal speed, two signals of constant amplitude but of different polarity are fed to the input of the executive motor. The first signal provides engine acceleration, the second - braking. At the moment of the removal of the second correction signal, the input intermittent effect is fully fulfilled, i.e., the backlash is selected and the engine is stopped (p9 0). Taking into account that at this time, the motor is supplied with a control signal Uj, which is not equal to zero, the output signal of the motor pb should be matched with the control voltage t / y. Therefore, in the presence of a control action t / y, the correction signal must be removed at the moment when at least half of the gap has been selected and the magnitude of the motor speed corresponds to the control voltage value / 7y. The considered task in the proposed engine control method is implemented as follows. At the moment when the motor speed passes through zero (0), two correction signals IJz and (Un constant amplitude Un-Signal Hz, proportional in duration to the value of the setting signal y, are intended to match the value of the output signal pv with the value of the control signal f / y t - t, k lj -sin№t, where ki is the proportionality factor between the signal value t / y and the input interval value 4 - ti of the signal Uz: Utf sin 0) 4 Uyf - 4, Signal Us, the duration of which is ts- ti is only dependent on the engine parameters and the value of Li; fta1 in the gearbox and, therefore, it is a constant value for a particular automatic system that provides engine acceleration for the purpose of forced selection of the backlash. 1 + e where k is the gain of the executive engine. Of the generated signals, ultrasound and t / s, the engine control circuit is supplied with the greatest duration. If this is the signal Oz (interval 4-ii in Fig. 1), which is typical for setting influences with relatively small amplitudes, then the actual speed of the motor pb at the time of the removal of the signal Us will exceed the value corresponding to the value of the setting signal Uy . If no special measures are taken, this will lead to a large overshoot in the system and ultimately to system instability. Therefore, at the moment ta, the control signal is applied to the control circuit C / 4, which adjusts the velocity pb with the control action Uy (the interval in Fig. I) and, and, (- sign Uy) at (4 - Л (4 - A), 0 when (, -O (a-O) But if the signal Uz is the most durable (interval tz-ti on stage 2), which is typical for relatively large setting influences, then the matching of the output signal pb with the value control action Uy will occur only at the moment the Uz signal is removed.

eliminates the introduction of a braking matching signal.

When using the proposed control method, the dependence of the time for selecting the backlash on the magnitude of the driver effect is significantly reduced, and the time for selecting the backlash is much less than when using previously known methods. A forced selection of backlash does not lead to excessive overshoot in the onstem. In addition, there is no need to use derivatives of the error signal and the output signal. Thus, the proposed control method of the executive motor allows, despite the presence of backlash in the gearbox, to obtain an automatic system with high quality.

The proposed method of controlling the executive engine can be implemented in various ways. For example, a wide variety of ambiguity denial schemes can be used to generate the f / i signal. The C / a and f / 4 signals can be implemented, for example, using fictional

circuits, subtraction circuits nln cpa (Attentions of currents (currents), signal Us-with the help of various release schemes.

Subject invention

A method for controlling an actuator of a servo drive with backlash in a mechanical transmission, which consists in sending a master signal and a signal for combining inertia into the motor control circuit, characterized in that, in order to improve the accuracy and improve the quality of transients, form two signals

one is proportional in duration to the magnitude of the driving signal, the other is constant in duration, and from these signals the most 1PO duration is supplied to the motor control circuit, and if it is a signal of a constant duration, then immediately after the end of the signal a reverse polarity (phase) signal is given whose duration is determined by the value of the master signal.

Fig f

u p6

Fig 2