SU1580317A1 - Device for controlling robot drive - Google Patents

Abstract

This invention relates to automatic control and can be used to create various robotic systems. The purpose of the invention is to improve the dynamic accuracy of drive motor control. To do this, the device containing the first adder, the first multiplier, the integrator, the second adder, the power amplifier, the electric motor, the current sensor, the third adder, the first comparator, and the first corrective block, the second multiplier, the second comparator, the logic block, the second corrective block and fourth adder. Thus, an electric motor control signal is generated in the device, containing the sum of the signal proportional to the error signal, a signal that is proportional to the integral of the error signal, and the coordinate-and-feedback feedback signal. The motor control signal constructed in such a way allows to counter the changes in the motor parameters by changing the weighting factor at the integral component, as well as uncontrolled changes in the momentary disturbances and disturbances caused by the presence of the back-electromotive force of the motor. 1 hp ff, 1 ill.

Description

The invention relates to automatic control and can be used, for example, in the creation of various robotic systems.

The aim of the invention is to increase the dynamic accuracy of driving a motor with variations in motor parameters and a change in load moment on the output shaft of the motor.

The drawing shows a diagram of the device.

The device contains the first adder 1, the first block 2 multiplying, the integrator 3, the second adder 4, the amplifier 5, the amplifier 6

power, drive motor 7, current sensor 8, third adder 9, first comparator 10, first correction unit 11, second multiplication unit 12, second comparator 13, logic unit 14, key 15, second correction unit 16 and fourth adder 17.

Logic block 14 contains multipliers 18 and 19, comparator 20 and master 21.

The device works as follows.

The first input of the first adder 1 is supplied with a signal of a predetermined value of the motor current, for example, from the regulator

ate

00

about

with

Vj

speed. The signal from current sensor 8, proportional to the amount of current flowing through the electric motor's main winding, is fed to the second input of the first adder 1. The error signal between the set and actual current values determined in adder 1 is amplified in amplifier 5 and through the second adder 4 and amplifier 6, the power is supplied to the control object, the electric motor 7 (direct current), causing an increase in the current in its core winding.

The output of the third adder 9 has the form

Ug Ul + KlU4-K2U8,

where Ki, 2 is the gain of the third adder at the corresponding input, which are selected based on the parameters of the electric motor 7 and the power amplifier 6;

Ui, LM, Us, and Ug are the output voltages of 1, 4, 8, and 9, respectively.

Comparator 10 implements the Uio SignUg function, i.e.

, f +1,; Ul ° - {- 1,

A single output signal is fed to the input of the correction unit 11, which implements the transfer function of the form

Wii (p)

one

Tf + 1

Tam,

electromagnetic constant

motor time.

The signal from block 11 goes to multiplication block 12, where it is multiplied by the output signal of comparator 13 (1Зз) corresponding to the sign of the device error signal, i.e.

 Ui, i.e.

 G +1, with Ui 0,

U13 1

-1, with Ui 0

As a result, the sign of the output signal of the multiplication unit 12 provides for negative feedback in the loop of the coordinate-operator feedback.

The output of block 12 is multiplied in block 2 by multiplying by the error signal and fed to the input of integrator 3, the output of which is the integral component of the motor control signal 7. In the adder 4, the proportional and integral components of the motor control signal are summed.

The output signal of the adder 9 characterizes at each instant of time the distance to the switching line, determined by the weighting factors of the quantities supplied to the inputs of the adder 9.

In logic block 14, based on the information about the sign and distance of the imaging point to the switching line, as well as information about the sign of the error signal, an operator-coordinate feedback signal (OCOS) is generated.

Multiplying the output signal of the adder 9

on its sign (the output signal of the comparator 10 corresponds to the sign Ug), the output of multiplication unit 18 is the output signal module of the adder 9. In multiplication unit 19, this signal is multiplied by the signal corresponding to the sign of the device error signal (Uis).

As a result, at the first output of logic block 14 (output of multiplication unit 19), an OCRE signal is generated, which parries uncontrolled torque perturbations on the output shaft of the electric motor.

The shape of the OCOS signal is determined in logic block 14 by the magnitude of the signal from the output of the adder 9 (Ug).

If the module lUg | U21, where U21 is the size of the threshold signal specified by the sensor 21, the key 15 is open, and the adder 17 receives only the signal from the output of the multiplication unit 19 with the weighting factor Kv. If IUgl U21. the key 15 is closed and the inputs of the adder 17 receive signals from the output of the key 15 with a weighting factor Ks and from the output of the corrective block 16 with a weighting factor equal to 1.

Consequently, the toll signal is defined as

, K8-lU9 | signUi. lUg | U2i; UOKOC- | (K8 + K4 + Wi6 (p). I Ug I sign Ui.l Ug,

where Wie (p) --- is the transfer function of the correction block 16; m;

Tm is the mechanical time constant of the motor,

K4 and Kv are the gain factors of the adder 17 at the corresponding input, selected depending on the parameters of the electric motor 7 and the range of effective torque disturbances.

When applying to the first input of the first adder 1 a signal of the type l (t), the voltage at the output of the adder 9 is positive. The signal corresponding to the sign of this signal from the output of the comparator 10 is fed to the input of the correction unit 11, the output signal of which smoothly increases, increasing the signal to the input of the integrator 3, therefore, the value of the integral component of the control signal.

With lUgl L) 21, key 15 is open and the motor control signal is defined as

Uynp K5Ui + K7 / lUil, Undt +

+ Kv lugl slgnUi,

where K is the gain of the adder 4 at the corresponding input, selected based on the requirements for the type of transient process and the parameters of the electric motor 7.

The second term of the control signal permits one to counter the change in the parameters of the electric motor, and the third, the uncontrolled changes in the moment disturbances.

In the process of testing the current set by the device, the error signal (Ui) decreases, the output coordinate value (Us) increases, and the signal (Ug) at the output of the adder 9 changes its sign. A change in the sign of Ug leads to a change in the sign of the output voltage of the second comparator 10 and the output of the second correction unit 11 decreases smoothly, thereby reducing the integral component of the motor control signal.

With further development of a given current value, the sign of the integral component changes, which leads to a decrease in the value of the motor control signal as the output coordinate approaches the specified value.

Reducing the value of the signal Ug causes the condition I Ug I U21 to be fulfilled and the motor control signal is defined as

iupr K5Ui + K7 / Uii-Unl dt +

about

+ Ap lUglstgn Ui + KU | Ug | signUi. +

+ Wi6 lUgl signUi. The fourth term of the control signal increases the component of the control signal, which counters the changes

5 moment perturbations.

The fifth term allows to parry not only the moment perturbations, but also the perturbations caused by the presence of counter-emf in the electric motor and the error

0 determine the rate of change of the motor current, and the introduction of the first correction unit 16 makes it possible to reduce the overshoot caused by a change in moment disturbances.

5B steady state in device

establishes a constant coefficient for the integral component and a certain constant value of the EQ signal. In case of a change in resistance P,

0 caused by both the deviation of RH and the spread of the P values for multi-motor robots, for example rhombic manipulators, changes the moment of change of the sign of the Ug signal, i.e. changes the weight coefficient at the integral component of the motor control signal, thereby ensuring the invariance of the quality indicators of the transient process to a change in the resistance of the main circuit

0 electric motor

Claims (2)

1. Drive control device 5 a robot containing a first adder, a first multiplication unit connected in series, an integrator, a second adder, a power amplifier and an electric motor, a current sensor connected in series, 0 the third adder, the first comparator and the first correction block, while the output of the first adder through the amplifier is connected to the second input of the second adder, one of the inputs of the first adder is connected to 5 by the input of the device, and its other input is connected to the output of the current sensor, the input of which is appropriately connected to the electric motor; moreover, the corresponding inputs of the third adder are connected to 0 outputs of the first and second adders, characterized in that, in order to increase the dynamic accuracy, it is equipped with a second multiplication unit, a second comparator and sequentially connected logical unit, a key, a second corrective unit and a fourth adder, the output of which is connected to the third input of the second adder , with the first input of the logical block connected to the output of the third adder, the second input of the logic unit is connected to the output of the first comparator, and its third input is connected to the output of the second comparator, the input of which is connected to the output of the first adder and the first input of the first multiplication unit, the second output of the logic unit , the remaining inputs of the fourth adder are connected respectively with the first output of the logic unit and the output of the key, and the output of the second comparator is connected to the second input of the first unit by multiplying audio, and a second input The second multiplication unit is connected to the output of the first adjustment unit. 2. The device according to claim 1, characterized in that the logic unit contains serially connected master and comparator, as well as serially connected two multiplication units, the inputs of the first of which are connected to the first and second inputs of the logic unit, and the second input and output of the second - respectively, with the third input and the first output of the logic unit, the output of the first multiplication unit being connected via a comparator to the second output of the logic unit.