JPH02118807A - Positioning control device - Google Patents

Abstract

PURPOSE:To raise the rigidity at the time of stopping without dropping the maximum speed at the time of being an action by providing a means to switch the ratio of a speed feedback quantity by the size of the absolute value of deviation. CONSTITUTION:The present position of an actuator 1 detected by a position detecting means 2 for a target position is subtracted and the deviation of a unit time is obtained. A speed command calculating means 3 calculates a speed command in proportion to the deviation. A speed detecting means 6 detects the speed of the actuator 1 and makes it into V. At a speed feedback quantity calculating means 7, when a speed feedback quantity ratio is KV, a speed feedback quantity VF becomes VF=KVXV. For KV the value is different at the time of being an action and at the time of being a stoppage, and the KV at the time of being the stoppage, is a value larger than the time of being the action to the extent in which the actuator 1 does not oscillate. For the decision whether the time of being the action or the time of being the stoppage is obtained, a speed feedback quantity switching means 5 executes the size comparison of a switching value thetaS and a deviation theta, it can be decided that when the deviation theta is larger, the time of the action is obtained and when it is smaller, the time of being the stoppage is obtained, and without dropping the maximum speed at the time of being the action, the rigidity at the time of being the stoppage can be raised.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a positioning control device for an actuator such as a motor.

BACKGROUND OF THE INVENTION A conventional positioning control method will be described below with reference to the drawings. FIG. 3 is a block diagram of a conventional positioning control method. In FIG. 3, 1 is an actuator, 2 is a position detecting means for detecting the current position of the actuator, 3 is a speed command calculating means, 6 is a speed detecting means, 7 is a speed feedback amount calculating means, and 8 is an actuator driving means.

The target position is fixed when stopped, but during operation it is updated every unit time and changes up to the positioning point. The current position of the actuator 1 detected by the position detecting means 2 is subtracted from the target position for each unit time to obtain a deviation for each unit time. The speed command calculating means 3 calculates a speed command proportional to the deviation. When the speed command is vc, the deviation is θ, and the proportional term is KP, the speed command Vc is expressed as Vc = K p xθ · Song (1).

The speed detection means 6 detects the speed of the actuator 1,
Let V be the speed. The speed foot reduction amount calculation means 7 calculates the speed foot reduction amount, and the speed feedback amount is vF and the speed feedback amount ratio is Kv.
Then, VF is Vy = Ky X V
``...''(2) Here the ratio K
v is a fixed value, and the maximum speed of actuator 1 is vMAX
If the maximum value of the speed command VC is vCMAX, it is expressed as follows.

Then, the actuator 1 is controlled by the actuator driving means 8 so that the speed deviation, which is the difference between the speed command VC and the speed feedback amount vF, becomes zero, thereby performing positioning control.

Problems to be Solved by the Invention However, in the above configuration, the ratio of the speed feedback amount is fixed, so especially in the case of an actuator that requires large rigidity when stopped, such as a direct drive motor, it is difficult to adjust the ratio of the speed feedback amount. It was necessary to increase the size and increase the viscosity, which caused the problem that the maximum speed during operation decreased accordingly.

In view of the above problems, the present invention provides a positioning control device that can increase the rigidity of an actuator when it is stopped without reducing its maximum operating speed.

Means for Solving the Problems A first invention according to claim 1 switches the ratio of the speed feedback amount depending on the magnitude of the deviation between the target position and the current position, and when the absolute value of the deviation is less than or equal to a set switching value. In this case, the positioning control device is characterized in that the ratio is increased.

In addition to the characteristic configuration of the first invention, a second invention according to claim 2 provides a switching value I of the speed feedback amount ratio when the absolute value of the deviation increases and a switching value II when the absolute value of the deviation decreases. This is a positioning control device characterized in that hysteresis is provided in switching the ratio of the velocity feedback amount by setting the switching value I and setting the switching value I to be larger than the switching value II.

According to the first invention, the speed feedback amount ratio is automatically increased in a region where the absolute value of the deviation is small, that is, when the speed feedback amount is stopped, because the device has means for switching the ratio of the speed feedback amount depending on the magnitude of the absolute value of the deviation. This makes it possible to increase the rigidity when stopping without reducing the maximum speed during operation.

Further, according to the second invention, there is provided a means for switching the speed feedback amount ratio depending on the magnitude of the absolute value of the deviation, and a switching value I of the speed feedback amount ratio when the absolute value of the deviation increases, and a switching value I when the absolute value of the deviation increases. Since the switching value II is provided to provide hysteresis, it is possible to increase the rigidity when stopping without reducing the maximum speed during operation, and also to reduce the effects of vibration etc. on low-speed operation near the switching value. can be eliminated.

Embodiments Examples of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 is a block diagram of a positioning control device in a first embodiment of the present invention.

In FIG. 1, 1 is an actuator, 2 is a position detection means, 3 is a speed command calculation means, 4 is a speed feedback amount ratio switching value storage means, 5 is a speed feedback amount ratio switching means, 6 is a speed detection means, and 7 is a speed feedback amount ratio switching means. Speed feedback amount calculation means, 8 is actuator driving means.

As explained in the conventional example, during operation, it operates with a speed command proportional to the deviation between the target position and the current position. That is, taking advantage of the fact that the deviation increases during operation, if the deviation is larger than the set value, it is determined that the system is operating, and if it is smaller, it is determined that the system is stopped, and the speed feed bank amount ratio is switched.

The explanation will be explained below according to FIG. The deviation per unit time is determined by subtracting the current position of the actuator 1 detected by the position detecting means 2 from the target position per unit time. The speed command calculating means 3 calculates a speed command proportional to the deviation. If the speed command is vc, the deviation is θ, and the proportional term is KP, then the speed command VC is: V C = K p Xθ ・・・・・・
・(Represented by →.

The speed detection means 6 detects the speed of the actuator 1,
Let V be the speed. Speed feedback amount calculation means 7
Now, when the speed feedback amount ratio is Ky, V is expressed as vF=KvXv. Here, the ratio Kv has different values when operating and when stopped, and if the operating ratio Kv1, the stopping ratio Kv2, the maximum speed of actuator 1 is vMAX, and the maximum value of the speed command vc is vcMA, then Kvl is It is expressed as In addition, (2) is set to a value larger than Kvl to the extent that the actuator 1 does not oscillate. To determine whether to operate or stop, the speed feedback switching means 5 compares the switching value θS stored in the switching value storage means 4 with the absolute value of the deviation θ. When it is large, it is assumed that it is in operation, and ■1 is adopted as the ratio. Rewriting the relational expression of the velocity feedback amount vF again, it becomes as follows.

V F = KVl
Positioning control is performed by controlling the actuator 1 with the actuator driving means 8 so that the speed deviation, which is the difference between c and the speed feedback amount vF, becomes zero.

According to the present embodiment, the speed feedback amount switching means 5 determines whether it is in operation or at rest, and the speed feedback ratio is automatically switched, so that the rigidity at stop can be increased without reducing the maximum speed during operation. Can be done.

Embodiment 2 FIG. 2 is a block diagram of a positioning control device in a second embodiment of the present invention.

In FIG. 2, the same parts as in FIG. 1 are given the same numbers, and their explanations will be omitted. The differences in FIG. 2 from FIG. 1 are switching value i storage means 9 for speed feedback amount ratio switching, switching value storage means 1o, and deviation increase/decrease determination means 1.
This is the point where 1 was set.

Assuming that the switching values stored in the switching value I storage means 9 and the switching value storage means 1d are respectively θs1 and θs2, their relationship is expressed by the following equation.

θs1>θs2 ・・・・・・
(@The deviation increase/decrease determination means 11 compares the absolute value of the previous deviation and the absolute value of the current deviation for each unit time, and determines whether the absolute value of the deviation is increasing or decreasing. If it is determined that the speed feedback amount ratio is present, the switching value is set to θs1 and sent to the speed feedback amount ratio switching means 5, and in the opposite case, θs2 is sent.By doing so, it is possible to provide hysteresis to the switching of the speed feedback amount ratio.

Therefore, according to this embodiment, in addition to the effects obtained in the first embodiment, it is possible to eliminate the influence of vibrations and the like even in low-speed operation near the switching value.

Effects of the Invention As described above, according to the first invention, since there is a means for switching the ratio of the multi-speed feedback amount depending on the magnitude of the absolute value of the deviation, the rigidity at the time of stopping can be improved without reducing the maximum speed during operation. can be raised.

Further, according to the second invention, there is provided a means for switching the ratio of the speed feedback amount (depending on the magnitude of the absolute value of the deviation), and a switching value ■ when the absolute value of the deviation increases and a switching value II when the absolute value of the deviation decreases. is provided to provide hysteresis in switching the speed feedback amount ratio.
In addition to the effects obtained by the invention described above, it is possible to eliminate the influence of vibrations and the like even in low-speed operation near the switching value.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a positioning control device according to a first embodiment of the present invention, FIG. 2 is a block diagram of a positioning control device according to a second embodiment of the present invention, and FIG. 3 is a block diagram of a conventional positioning control device. It is a block diagram. 1...Actuator, 2...Position detection means, 3...Speed command calculation means, 4...Switching value storage means, 5...Speed feedback amount ratio Switching means, 6... Speed detection means, 7...
... Speed feedback amount calculation means, 8 ... Actuator drive means, 9 ... Switching value I storage means, 10 ... Switching value ■ storage means, 11 ...
... Deviation increase/decrease judgment means.

Claims (2)

[Claims] (1) In a control device that performs positioning by performing speed feedback to a speed command for each unit time calculated from the deviation between the current position and the target position of an actuator, the ratio of the speed feedback amount is switched depending on the magnitude of the deviation, and the A positioning control device characterized in that the ratio is increased when the absolute value of is less than or equal to a set switching value. (2) Set the switching value I when the deviation increases and the switching value II when it decreases, and set the switching value I to the switching value
2. The positioning control device according to claim 1, wherein hysteresis is provided in switching the ratio of the speed feedback amount by setting the speed feedback amount larger than II.