JPH0464898A - Servo controller - Google Patents

Abstract

PURPOSE:To improve follow-up performance and suppress disturbance quickly by a method wherein a feedforward control unit, outputting a speed command and a torque command obtained from a position commanding signal into a control system, is added to add the disturbance estimating value of torque, based on the output signal of the feedforward control unit and the speed detecting signal of a machine to be controlled, to the control system. CONSTITUTION:A position commanding value thetar is inputted into a subtractor 11 and a feedforward control unit 12. A first operating unit 12a in the control unit 12 obtains a speed control amount from the position command thetar while the second operating unit 12b of the control unit 12 obtains an inertia force control amount. This output signal is added by an adder 19 to obtain a feedforward amount T and is inputted into an adder 18 while the torque command T is inputted into a machine 21 to be controlled and a disturbance observer 22. In this case, the position and the moving speed of a moving body in the machine 21 to be controlled are detected and the detected speed and position are inputted into the subtractor 11, the disturbance observer 22 and the subtractor 14 respectively. The disturbance estimating value (d) is added to a torque commanding value by the adder 18 to remove the affection of the disturbance of torque.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to, for example, turning in a gun, turret, etc. of a special vehicle;
The present invention relates to a servo control device that controls heave motion.

[Prior Art] Conventionally, in guns, turrets, etc. of special vehicles, positioning control associated with turning and heave movements has been performed by a servo control device. In this case, the target value is given a position command (or velocity integral), and a feedback loop compensates for disturbances, and integral control compensates for minute offset deviations with respect to the target value.

[Problems to be Solved by the Invention] As mentioned above, conventional servo control devices for special vehicles, etc. perform control using a feedback loop, so there is a problem that the phase delay is large due to the influence of integral control and tracking performance is poor. was there. In addition, when removing the effects of torque disturbance, we follow up with a feedback loop related to position and speed, so it takes time to suppress it.
There is a problem in that the compensation operation becomes slow in response to torque disturbances such as friction and vehicle body motion disturbances.

The present invention has been made in view of the above points, and an object of the present invention is to provide a servo control device that can improve tracking performance for a target value and can quickly suppress friction and vehicle body disturbance.

[Means and effects for solving the problem] The present invention provides a servo control device for driving and controlling a machine having turning and heave motion functions. In addition to adding a feedforward control unit that performs feedforward control by outputting speed commands and torque commands based on the A disturbance observer is added that adds estimated values to the control system to eliminate torque disturbances.

In the above configuration, when a position command signal is input, the feedforward control section differentiates the position command signal to obtain velocity and acceleration, and then multiplies these velocity and acceleration by velocity resistance and inertia, respectively. and added to the control system as speed commands and torque commands. As a result, the tracking performance of the controlled machine can be improved. Further, the output signal of the control system and the speed detection signal of the controlled machine are input to the disturbance observer, and the torque disturbance is estimated in real time. The estimated disturbance value output from the disturbance observer is added to the control system to suppress torque disturbance.

Further, the present invention provides a servo control device for driving and controlling a machine having turning and heave motion functions, and is provided with a switching means for switching and inputting a position command signal or a speed disturbance signal obtained by a sensor. The resulting signal is differentiated to determine speed and acceleration, and a speed command and torque command based on this speed and acceleration are output to the control system for feedforward control.

In the above configuration, when a position command signal is selected by the switching means, this position command signal is differentiated and a speed command/torque command based on speed/acceleration is output to the control system to perform feedforward control. When speed/torque commands based on position command signals are determined and added to the control system in this manner, the followability of the controlled machine can be improved.

Further, when the speed disturbance signal is selected by the switching means, a speed command and a torque command are output to the control system based on the speed disturbance signal, and feedforward control is performed. In this way, when speed/torque commands based on speed disturbances are obtained and added to the control system, stability of the controlled machine against speed disturbances can be improved.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

(First Embodiment) FIG. 1 is a block diagram showing the configuration of a servo control device according to a first embodiment of the present invention. A position command value θr given in response to a steering wheel operation or the like is input to the + side terminal of the subtractor 11 and is also input to the feedforward control unit 12 . The output signal of the subtracter 11 is amplified by the amplifier 13 and then input to the integrator 15 via the + side terminal of the subtracter 14. The output signal of this integrator 15 is passed through a phase compensator 16 and a notch filter 7 to an adder 18.
is input.

On the other hand, the feedforward control unit 12 includes a first calculation unit 12a, a second calculation unit], and 2b.

The first calculation unit 1.2a calculates the speed by differentiating the position command value Or, and further multiplies it by the speed resistance K to obtain the speed control amount. The second calculation unit 12b calculates the acceleration by differentiating the command value θr twice, and further multiplies it by the inertia J to obtain the inertial force control amount. The calculation results of the calculation units 12a and 12b, that is, the output signal of the feedforward control unit 12, are added by an adder 19 to become the feedforward amount T,
It is input to the adder 18.

The torque command T output from the adder 18 is input to the controlled machine 21 and also to the disturbance observer 22 . The drive device of the controlled machine 21 is controlled by the torque command T from the adder 18. At this time, the position and moving speed of the moving body in the controlled machine 21 are detected, the position detection signal θ is input to one terminal of the subtractor 11, and the speed detection signal θ' is input to the one terminal of the disturbance observer 22 and the subtractor 14. input to the side terminal. In this case, the position detection signal θ and speed detection signal θ' are switched depending on the power mode and stability mode.

The disturbance observer 22 includes a low-pass filter 22a,
It consists of an arithmetic unit 22b and a subtracter 22c, and the torque command T from the adder 18 is input to a low-pass filter 22a.
The speed detection signal θ′ from the controlled machine 21 is sent to the calculation unit 22b.
is input. The output signal of the low-pass filter 22a is input to the + side terminal of the subtracter 22c, and the output signal of the arithmetic unit 22b is input to the one side terminal of the subtracter 22c.

The output signal of this subtracter 22c is then input to the adder 18. The disturbance observer 22 estimates torque disturbances such as friction and vehicle motion disturbances in real time, and adds the estimated disturbance value d to the torque command value using an adder 18 to remove the influence of the torque disturbance.

Next, the operation of the above embodiment will be explained.

First, the operation of the feedforward control section 12 will be explained. The equation of motion is: Jθ' - Td - θ' (1) where J is inertia, T is torque (input side), d is disturbance torque, and K is speed resistance.

is given by Since the disturbance d is canceled by the disturbance observer 22, if it is ignored here, the above equation (1) becomes Jθ' −T− θ′ (2). When the command value indicating the target position is θr, the feedforward control amount T is calculated as θ′ r + Jθ from equation (2).
'r...(3) is obtained.

In the feedforward control section 12, the first calculation section 12a
The command value θ' is differentiated to find the speed θ', and this is multiplied by the speed resistance K to find the speed control amount θ'r.At the same time, the second calculation section 12b differentiates the command value θr twice. Determine the acceleration θ' and multiply it by the inertia J to determine the inertial force control amount Jθ'.
a.

The adder 19 adds θ′ r and the inertia force control amount Jθ′r to the speed control amount output from 12 b to obtain the feedforward control amount T, and this control amount T is added to the adder 18
input to the control system via. This makes it possible to control the following motion of the controlled machine up to the acceleration.

On the other hand, the disturbance observer 22 performs the following operations. From the above equation (1), the disturbance d is d-T-Jθ'-
θ' can be determined by (4). In this equation (4), the acceleration θ' is obtained by approximately differentiating the speed detection signal θ' fed back from the controlled machine 21. Laplace transform is shown as follows: where S is the Laplace operator and ToB is the filter time constant.

becomes. Therefore, the estimated disturbance value d is It can be found by

That is, the disturbance observer 22 approximately differentiates the speed detection signal θ' from the controlled machine 21 in the calculation unit 22b to obtain the acceleration θ', and multiplies this by the inertia J to obtain the inertial force Jθ' (approximate value). Calculate. In addition, the calculation section 22b
is obtained by multiplying the speed detection signal θ′ by the speed resistance K.
get. Then, the disturbance observer 22 calculates the inertial force Jθ' from the torque T obtained through the low-pass filter 22a.
By subtracting θ′ from and with the subtractor 23, (6)
The equation is executed and the estimated disturbance value d is determined. This estimated disturbance value d is input to the adder 18 and added to the torque command. This performs disturbance cancellation.

Note that the set inertia J in the feedforward control section 12 and the disturbance observer 22 is set in the power mode,
Set to different values depending on stability mode.

(Second example) Next, a second embodiment of the present invention will be described.

The servo control device shown in the second embodiment is obtained by omitting the disturbance observer 22 from the circuit shown in FIG. Components that are the same as those in the embodiment shown in FIG.

The feedforward control section 30 includes a first calculation section 31
, a second calculation section 32, and a mode changeover switch 33. The first calculation unit 31 differentiates the position command value or to obtain the speed, and transmits the speed signal to the mode changeover switch 3.
input to the first fixed contact a of No. 3. Further, a speed disturbance signal θd' obtained from a sensor (not shown) is input to the second fixed contact of the mode changeover switch 33.

One of the command value θr and the speed disturbance signal θd' is selected by the mode changeover switch 33, and is input to the second arithmetic unit 32 as well as to the child terminal of the subtracter 14. The second calculation unit 32 calculates acceleration by differentiating the signal selected by the mode changeover switch 33, and further multiplies the signal by inertia J to obtain an inertial force control amount. This second calculation unit 32
The calculation result is taken out from the feedforward control section 30 as the feedforward amount T, and inputted to the adder 18. This adder 18 adds the feedforward amount T and the output signal of the notch filter 17, and outputs the result to the controlled machine 21 as a torque command.

In the above configuration, the mode changeover switch 33 switches between a power mode in which the command value θ' is input and a stable mode in which the speed disturbance signal θd' obtained by the sensor is input. teeth,
It is done according to the purpose of use.

When the mode selector switch 33 is switched to the fixed contact a side to specify the power mode, when the command value θr is given, the command value θr is differentiated by the first calculation unit 31 of the feedforward control unit 30, and the speed signal is Desired. This speed signal is selected by the mode changeover switch 33 and input to the second calculation section 32. The second calculation unit 32 differentiates the speed signal to obtain an acceleration signal, and further multiplies this acceleration signal by inertia J to obtain a speed/torque command, which is added to the control system to compensate for phase delay.

When the feedforward control unit 30 obtains a speed/torque command based on the command value θr and adds it to the control system as described above, the followability of the controlled machine 21 can be improved.

In addition, when the mode changeover switch 33 is switched to the fixed contact 5 side to specify the stable mode, when the speed disturbance signal θd' obtained by the sensor is input, this speed disturbance signal θd' is 33 and sent to the second calculation section 32. This second calculation unit 32 differentiates the speed disturbance signal θd' to obtain an acceleration signal, and further multiplies this acceleration signal by inertia J to calculate the speed/disturbance signal θd'.
Find the torque command and add it to the control system.

When the feedforward control unit 30 obtains the speed/torque command based on the speed disturbance signal θd' and adds it to the control system as described above, the stability of the controlled machine 21 against speed disturbances can be improved. . Therefore, depending on the purpose of use, the position command value θ can be set by the mode changeover switch 33.
By selecting r or speed disturbance signal θd',
Optimal control can be performed according to conditions.

[Effects of the Invention] As detailed above, according to the present invention, by adding a feedforward control section that differentiates a position command signal, calculates speed and acceleration, and outputs a speed and torque command,
Even the acceleration can be adjusted, improving tracking performance. Furthermore, torque disturbance can be suppressed by providing a disturbance observer, estimating torque disturbance in real time, and adding this estimated value to the torque command value to cancel the influence.

The present invention also provides a power mode in which a position command signal is differentiated, speed and acceleration are calculated, and a speed and torque command is output.
By adding a feedforward control unit that can arbitrarily select between a stable mode that outputs speed and torque commands based on the speed disturbance signal obtained by the sensor, tracking performance in power mode is improved, and stability mode is improved. Improved stability can be achieved with one feedforward system.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a circuit configuration of a servo control device according to a first embodiment of the invention, and FIG. 2 is a block diagram showing a circuit configuration of a servo control device according to a second embodiment of the invention. 1.1. ], 4... O reducer, 12... Feedforward control unit, 13... Amplifier, ]5... Integrator, 16... Phase compensator, 17... Notch filter,
18.19... Adder, 21... Controlled machine, 22
... Disturbance observer, 30... Feedforward control section, 31... First calculation section, 32... Second calculation section, 33... Mode changeover switch. Applicant's agent Patent attorney Takehiko Suzue

Claims (2)

[Claims] (1) In a servo control device that drives and controls a machine that has turning and heave motion functions, a control system that integrates a position command signal with respect to a movement target position to drive and control the controlled machine to the target position, and a control system that controls the drive of the controlled machine to the target position, and the position command signal and a feedforward control section that performs feedforward control by differentiating the speed and acceleration, and outputs speed commands and torque commands based on the speed and acceleration to the control system, and output signals of the control system and the output signal of the controlled machine. A servo control device comprising: a disturbance observer that estimates torque disturbance based on a speed detection signal and adds this estimated value to the control system to eliminate the torque disturbance. (2) In a servo control device that drives and controls a machine that has turning and heave motion functions, a control system that integrates a position command signal with respect to a movement target position to drive and control the controlled machine to the target position, and a control system that controls the drive of the controlled machine to the target position, and the position command signal Alternatively, there is a switching means for switching and inputting the speed disturbance signal obtained by the sensor, and the signal selected by this means is differentiated to obtain speed/acceleration, and the speed command/torque command based on this speed/acceleration is transmitted to the control system. 1. A servo control device comprising: a feedforward control section that performs feedforward control by outputting an output to a servo controller.