SU1406565A1 - Servo electric drive with variable inertia moment - Google Patents

Abstract

Inventive ie refers to electrical engineering, in particular to automated electric drives, and can be used in drives of mechanisms with varying reduced moment of inertia, for example, industrial robots. The aim of the invention is to improve the accuracy of the follow-up electric drive when the load torque changes. The following electric drive contains regulator 1, regulator 2 speeds, blocks 3, 16 multiplications, regulator 4 currents, controlled converter 5, motor 6 with a sensor 7 currents and 8 speeds, actuator 9 with a sensor 10, block 11 static moment determination, adder 12, dividing unit 13, integrator 14, determining unit 15, dividing the derivative. Tracking accuracy is improved due to sensation in the speed control loop due to changes in the reduced moment of inertia. 1 il. S

Description

The invention relates to electrical engineering, in particular, to an automatic BaHHOhfy electric drive, and can be used in drives of mechanisms with varying reduced moment of inertia, for example, in industrial robots.

 The aim of the invention is to improve the accuracy of the follow-up drive when the load torque changes.

The drawing shows a block diagram of a servo drive with a variable moment of inertia.

The following electric drive contains 1 position controller, 2 speed controller, first multiply unit 3, 4-current controller, control converter 5, motor 6 with current sensors 7 and 8 speed, actuator 9 with position sensor 10, block 11 static moment determination, adder 12, dividing unit 13, integrator 14, derivative determining unit 15, second multiplying unit 16.

The drive works as follows.

From the output of position controller 1, the speed reference signal is fed to the input of speed controller 2, which, together with multiplication unit 3, forms a self-adjusting speed controller, and the speed controller realizes the transfer function determined from the condition of singleness of the moment of inertia. The speed feedback signal from the output of the speed sensor 8 is fed to the feedback input of the speed controller 2, the output of which is fed to the input of the first multiplication unit 3. The other input of the first multiplication unit 3 from the output of the integrator 14 receives a signal proportional to the non-total reduced moment of inertia 1. As the drive inertia changes, the signal proportional changes, resulting in a change in the signal at the multiplication unit 3, which is equivalent to parameters of self-adjusting speed controller.

The determination of value 1 is as follows.

The equation of motion of an electric drive with a variable moment of inertia is as follows:

dco

T (.,). -liiii i.

wi Л1гМ

dt

dif

Multiplying and dividing the second term in the right side of the equation of motion by dt and taking into account that dtf / dt w, we obtain the equation of motion in the following form:

du)

M-Mjt) 1 () dlgCcf) 2 dt

From this equation it follows that

dl (v) 2 with x. , du, ---- - --- (M-Mc (4) -I (4) -: ir-J.

dt

dt

The last equation describes the signal that is fed to the input of the integrator 14 to obtain the value of the moment of inertia 1. This signal is generated as follows.

From the output of the current sensor 7 to the first | Input of the adder 12 receives a signal

proportional to the electromagnetic moment of the motor M. The second input of the adder 12 from the output of block 11 receives a signal proportional to the static moment Mc (h) "

When the manipulator of an industrial robot moves in space, the orientation of the link of the manipulator changes, as a result of which the static moment of the electric drive changes in accordance with

M

 t icosif

where ha

. g

- mass of a link;

distance from the axis of rotation to the center of mass;

g - free fall acceleration -,

1, i - efficiency and transmission ratio,

1 -: angle of rotation of the link - signal of position sensor 10. The third input of the adder 12 receives a signal from the output of the second multiplication unit 16, the inputs of which are fed from the output of the integrator 14, and from the output of the derivative determination unit 15, the input signal of which is proportional to the motor speed

W.

in block 13 dividing the division of the signal from the output of the adder

12 to a signal proportional to the speed a, and a signal proportional to dl (4) / dt .. From the output of dividing unit 13, is fed to the input of the integrator from the output of which the evaluation signal I. (t |) is fed to multiplication unit 3.

Thus, an improvement in the quality of speed control and an increase in tracking accuracy in an electric drive with a variable moment of inertia is achieved by increasing the accuracy of determining the total reduced moment of inertia.

Claims (1)

Invention Formula A traction electric drive with a variable moment of inertia, containing a position controller, connected by a job input to the position reference input of a follower drive with a variable inertia, and an output to the task input of the speed regulator connected by the output to the first input of the first multiplication unit, the output of which is connected with the input of the current regulator, connected via the control converter to the input of the motor, equipped with a current sensor and a speed sensor and under five 0 five 0 The output is connected to the actuator input moment of the mechanism, equipped with a position sensor, connected by an output to the feedback input of the position regulator, the output of the speed sensor is connected to the feedback input of the speed regulator, the output of the current sensor is connected to the feedback input of the current regulator and the first input of the adder, as well as containing the second multiplication unit and the integrator characterized in that, in order to increase the accuracy of the following electric drive with a variable moment of inertia as the load moment changes, The unit for determining the derivative, the dividing unit and the static moment determining unit, whose input is connected to the output of the position sensor, and the output to the second input of the adder, whose output is connected to the input of the divisible division unit, connected to the output of the speed sensor, and through the derivative determining unit to the first input of the second multiplication unit connected by the output to the third input of the adder, the output of the division unit is connected via an integrator to the second inputs of the first and second multiplication units.