JPS61281311A - Command value generating circuit - Google Patents

Abstract

PURPOSE:To improve the positioning speed of a robot hand, etc. by increasing a command value at a high acceleration or speed, and to bring it close to a target value in a short time. CONSTITUTION:A command value generating circuit is constituted of the first and the second setting parts 1, 2, comparators 3, 6, a selecting circuit 4, an arithmetic circuit 5, a function generator 7, and a change-over switch 8. In this state, zero and also two kinds of large and small accelerations (a) and speeds (v) of positive are set in advance to the first and the second setting parts 1, 2, and first of all, a command value is increased by a large acceleration a2, and while a control deviation (e) exceeds a reference value (d), the command value is increased by switching said acceleration to a small acceleration a1. When this speed reaches to a large speed v2, the value is varied at a constant speed v2 by setting the acceleration to zero. Also, if the control deviation (e) exceeds the reference value (d), when the command value is being increased at the constant speed v2, the command value is increased by switching the speed to a small speed v1.

Description

[Detailed Description of the Invention] [Summary] A command value generation circuit provided in a servo control device used for positioning a robot hand, etc., which changes a command value change curve according to the difference between the command value and a controlled amount. The control speed has been improved.

[Industrial application field]

The present invention relates to a servo control device for positioning control, and more specifically, to a servo control device that provides a command value while smoothly changing it from zero to a target value.

FIG. 4 is a basic block diagram of a servo control system including a command value generation circuit, and 11 is a command value generation circuit.

12 is a servo mechanism, 12a is a control unit, 13 is a controlled object, r is a command value, e is a control deviation, U is an operation amount,
y indicates the control amount.

In this configuration, when the target value of the control amount y to be given to the controlled object 13 is R, as illustrated in FIG. r (t) is generated in the command value generation circuit 11,
This is given to the servo mechanism 12 as a command value, and the controlled object 1
By controlling the control amount y to follow the noise, abnormalities such as overshoot or oscillation are prevented from occurring in each part of the servo system, especially in the controlled object 13.

At this time, it is desirable that the configuration of the command value generation circuit 11 takes into account not only the stabilization of the control system but also the improvement of the control speed.

fd l/rIJ111 1' is register 1a for setting zero and acceleration a for positive value
A setting section consisting of a register 1b for setting 1.

2' is a register for setting a positive value speed vl.

5' is the first part of the command value 1 (t ) is an arithmetic circuit that generates

6 is the first part of the command value generated by the arithmetic circuit 5'
1 (t) with a target value R, and generates a control signal S2 when the difference reaches a predetermined value.

7, as shown by the dotted lines in Fig. 5 fa) and (b).

The second part of the command value 2 (
t).

8 is the arithmetic circuit 5 while the control signal s2 is not applied.
' is generated by a switch that selects the first part 1 (tl) of the command value generated and switches to the second part 2 (t) of the command value generated by the function generator 7 when the control signal s2 is given. be.

Note that the arithmetic circuit 5' selects the acceleration al to be stored in the register 1b while the control signal s3 is not applied, and selects the acceleration al to be stored in the register 1a when the control signal s3 is applied, using a switch 58' and a switch 5a. A buffer 5b temporarily stores the acceleration setting value selected by ', and a buffer 5b at the time point (
By adding the memory contents of the buffer 5b to the velocity value v(k) at time point (k+1), the velocity value v(k) at time point (k+1) is obtained.
+1), a first adder 5c that outputs
A buffer 5d temporarily stores the output of the buffer 5b, a multiplier 5e multiplies the stored contents of the buffer 5b by 2, + the command value r at time (k) and the speed value V(
a second adder 5 that adds the output of the multiplier 5e and the output of the multiplier 5e and outputs the command value r (k+1) at time (k+1).
f.

Pants 15g temporarily stores the output of the second adder 5f.

Also, the speed value v1 stored in the register 2' is compared with the output of the first adder 5C, and the output of the adder 5C is determined to be v.
1, and a comparator 5h that generates a control signal S3 when the signal S3 is reached.

That is, the command value generation circuit with the above configuration is shown in FIG. 5('b).
As shown in the following, the command value r (tl is accelerated at the acceleration a1 until the speed reaches vl, and when the speed reaches vl, the acceleration is set to zero and the speed is changed at a constant speed v1, and then it is decelerated. , is configured to generate a command value r (t) that continuously and gradually changes up to the target value R, as shown in FIG.

[Problem that the invention seeks to solve]

In the command value generation circuit having the above configuration, the command value r (t
) is the change curve between the acceleration setting value a1 and the speed setting value v.
1 is determined as one type by 1 and 2, and is a type of failure such as overshoot or oscillation due to overflow or saturation that occurs in various parts of the control system due to an excessive increase in the difference between the command value r and the controlled variable y, that is, the control deviation e. occurs.

Therefore, in order to avoid an excessive increase in the control deviation e.

Both the acceleration setting value a1 and the speed setting value v1 are set to small values.

Therefore, there is a problem that it takes a long time for the command value to reach the target value. Therefore, an object of the present invention is to bring the command value close to the target value in a short time while avoiding an excessive increase in the control deviation e.

[Means for solving problems]

FIG. 1 is a block diagram of the principle of the present invention.

1 is a first setting section for setting a plurality of positive acceleration values a1 and 82 in addition to zero.

2 is a second setting section for setting a plurality of positive velocity values ν1 and v2 excluding zero.

A comparator 3 compares the control deviation e with a preset reference value d and generates a control signal s1 when the control deviation e exceeds the reference deviation d.

4 is either the acceleration value a1 or a2 set in the first setting section 1 and the speed value V set in the second setting section 2, depending on the compression result in the comparator 3. v2 and outputs the selected acceleration value ac, its sign-inverted value -ac, and the selected velocity value vc.

5 in accordance with the output of the 1 selection circuit 4 as shown in FIG. 2(a).
As shown by the solid line in (b), the first part of the command value 1 ( an arithmetic circuit that generates t).

6 is the first part 1 (of the command value generated by the arithmetic circuit 5).
t) with a target value R and generates a control signal S2 when the difference reaches a predetermined value.

7 is shown by the dotted line in Figure 2 (Al/Mon).

The second part of the command value 2 (1
).

8 is the arithmetic circuit 5 while the control signal s2 is not applied.
is a switch that selects the first part molecule 1 (t) of the command value that is generated and switches it to the second part molecule 2 (t) of the command value that is generated by the function generator 7 when the control signal s2 is given. be.

[Effect]

That is, in the first setting section 1, in addition to zero, there are 2 large and small values.
Set the positive acceleration values a1 and 82 of the type.

The second setting section contains two types of positive velocity values, large and small, v1 and ν2.
As shown in Fig. 2, the command value r(t) is initially increased with the larger acceleration a2, and while the control deviation e exceeds the reference value d, it is switched to the smaller acceleration a1. Increase the command value r (t).

In this way, the command value r (when the speed of tl reaches the larger speed v2, the acceleration is set to zero and the constant speed v2
Change it with.

In addition, if the control deviation e exceeds the reference value d while increasing the command value r (t) at a constant speed v2, the smaller speed vi
, and increase the command value r (t).

After this, when the difference between the command value r (tl and the target value R reaches a predetermined value, the change rate of the command value r ([) is decreased according to the change curve generated by the function generator 7 until the target value R is reached. change.

In this way, the command value r (tl
can be brought close to the target value R in a short time.

〔Example〕

FIG. 3 is a block diagram of an embodiment of the present invention.

The first setting section 1 is composed of three registers 1a, 1b, and an IC, each of which has a value of zero, a first acceleration value a1, and an IC.
Set the second acceleration value a2 (al < a2).

The second setting section 2 is composed of two registers 2a and 2b, in which a first speed value v1 and a second speed value v2 (where vl < v2) are set respectively.゛The selection circuit 4 includes a switch 4a that selects the register 1c while the control signal s1 is not input, and selects the register 1b while the control signal S1 is input, and a control signal s1.
The switch 4b, which selects the register 2b while the control signal s1 is not input, and selects the register 2a while the control signal s1 is input, the sign inverting circuit 4c+, and the control signal s1 generated by the comparator 3, It is comprised of a switch 4d that is switched to switch 4a or 4b depending on whether the value r(1) is during acceleration or constant speed.

The arithmetic circuit 5 outputs the setting value of the register 1a, the output of the sign inverting circuit 4c, -ac, and the switch 4a according to the control signal s3.
A switch 5a+ that selects one of the acceleration setting values ac selected by the switch 5a+ A buffer 5b that temporarily stores the acceleration setting value selected by the switch 5a, and a buffer 5b that stores the velocity value v(k) at the time point (g)). A first adder 5c that adds the contents and outputs the velocity value v (k+1) at time (k+1), a buffer 5d that temporarily stores the output of the first adder 5c, and a buffer 5b whose stored contents are set to 2. The multiplier 5e adds the command value r(k) at time (k), the speed value v(kl) at time (k), and the output of the multiplier 5e to obtain the command value r(k+1) at time (k+1).
1), a buffer 5g that temporarily stores the output of the second adder 5f, and a speed setting value vc selected by the switch 4b and the first adder 5c.
The output of the adder 5c is compared with the output of the switch 4b.
to the switch 5a, depending on whether it is equal to, greater than, or smaller than 1 to the selected speed setting value vc.

It is composed of a comparator 5h that generates any one of three types of control signals s3a-53b-53c.

That is, the command value generation circuit according to the above embodiment is as follows.

As shown in Figure 2, until the speed of the command value r (t) reaches v2, it accelerates at a large acceleration a2 as long as the control deviation e does not exceed the reference value d, and the control deviation e exceeds the reference value d. In this case, the control signal s1 is applied to the switch 4a, and the acceleration is reduced to al. When the speed reaches v2 in this manner, the control signal s3a is applied from the comparator 5h to the switch 5a, and the acceleration becomes zero.

During constant speed, the speed changes at a large speed v2 as long as the control deviation e does not exceed the reference value d, but when the control deviation e exceeds the reference value d, the control signal s1 is applied to the switch 4b and the speed is reduced to vl.

Due to the decrease in speed, a control signal s3b is applied from the comparator 5h to the switch 5a, and the acceleration becomes -ac and the speed becomes v.
When decreasing from 2 to vl, the acceleration becomes zero again.

After this, when the difference from the target value reaches a predetermined value.

The command value r (
t) is changed to the target value R while decreasing the rate of change.

In this way, by increasing the command value r(t) with as large an acceleration or velocity as possible.

The command value r (t) can be brought close to the target value R in a short time.

In this embodiment, there is one type of reference value d to be compared with the control deviation e, and the acceleration is set to al and a 2 + the speed is set to 2 of vl and v2.
Although the reference value is switched to two or more types, it is also possible to switch the acceleration and speed to three or more types.

〔Effect of the invention〕

As explained above, according to the present invention, the command value can be increased to the target value in a short time.

For example, the positioning speed of a robot hand or the like can be improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the principle of the present invention. FIG. 2 is a detailed explanatory diagram of the present invention. FIG. 3 is a configuration diagram of the embodiment. Figure 4 is a basic block diagram of the servo control system. FIG. 5 is an explanatory diagram of the command value generation circuit. FIG. 6 is a configuration diagram of a conventional example. In the figure. 1 is the first setting section, 2 is the second setting section. 3 and 6 are comparators, and 4 is a selection circuit. 5 is an arithmetic circuit, and 7 is a function generator. 8 is a switch, and 11 is a command value generation circuit. 12 is a servo mechanism, and 13 is a controlled object. r is the command value, e is the control deviation. v-7F Dake'1 Misakijo's standard plan 2 diagram Tea 4 Heat Akira + # Tato student troubled eyebrows (January drawing) Rod 5 diagram

Claims (1)

[Scope of Claim] A command value generation circuit provided in a servo control device that controls a control amount so as to follow a command value that changes according to given acceleration and velocity, A first setting section (1) that sets the value of , and a second setting section (2) that sets multiple speed values except zero.
), a comparator (3) for comparing the control deviation (e) with a preset reference value (d), and selection of one of the plurality of types of acceleration set above according to the comparison result in the comparator (3). and a selection circuit (4) for selecting at least one of the plurality of speeds set.