JPH0231407B2 - ICHIGIMEKIKONOSEIGYOHOSHIKI - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a positioning control device that positions a controlled object by applying an operational input to a drive device that drives the controlled object, and in particular, the present invention relates to a positioning control device that positions the controlled object by applying an operation input to a drive device that drives the controlled object, and particularly when the controlled object is a coil feeder or the like. The present invention relates to a method for configuring a position control system that requires high-speed positioning operations.

[Conventional technology]

Conventionally, as a configuration method for this type of position control system,
The following methods are known: (a) a method using only feedback control, (b) a method using only feedback control, and (c) a method of simply applying feedback control to the feedback control system.

FIG. 2 is a block diagram showing the configuration according to method (a), in which the position control device 10a gives only the speed command _{Ω r as} the operation input U a to the drive device (motor drive) 20. . Here, the drive device 20 uses a speed feedback element 21 (its gain is k _v ) to feedback the actual speed (angular velocity of the motor) Ω of the controlled object 30 and an operation input U _a (Ω _r ), which is a target value. A subtracter 22 that subtracts the output of the speed feedback element 21 and an open-loop speed control system 23 that inputs the output of the subtracter 22 and outputs a drive signal (motor current) I to the controlled object 30 (its speed control open-loop transmission relationship). is G _v (S))
including.

In addition, the controlled object 30 is a current speed conversion means 31 which inputs the drive signal I and outputs the speed Ω (its transfer function is k _t /JS, where k _t is the torque constant, J is the rotor inertia, and S is the Laplace transform. It includes an integrator 32 (its transfer function is 1/S) which inputs the velocity Ω and the velocity Ω and outputs the position (motor displacement angle) θ.

FIG. 3 is a block diagram showing a configuration according to the method (b), in which parts having the same functions as those in FIG. 2 are given the same reference numerals. The difference from FIG. 2 is that as the operation input U _b output from the position control device 10b,
The position command θ _r obtained by integrating the speed command Ω _r output from the speed pattern generator 11 by the integrator 12
and the actual position θ of the controlled object 30 is obtained by the subtractor 13, and the position deviation E _b is _calculated by the amplifier 14.
(The deviation gain is K ₁ ) is used.

FIG. 4 is a block diagram showing a configuration according to method (c), in which parts having the same functions as those in FIG. 3 are given the same reference numerals. The difference from FIG. 3 is that as the operation input U _e output from the position control device 10c,
A signal obtained by adding the position feedback signal output from the amplifier 14 and the position command _Ωr output from the speed pattern generator 11 by an adder 15 is used.

[Problem that the invention seeks to solve]

However, in method (a), the position control device 1
Even if the speed command Ω _r output from 0a as the operation input U _a is planned to displace the controlled object 30 to a predetermined position within a predetermined time, unpredictable disturbances applied to the controlled object 30 Due to these factors, there was a drawback that the positional accuracy at the time of stopping deteriorated. In addition, in the method (b), a closed loop speed control system 40 in which the rapid response of the system is included inside the system.
(In the part including the drive device 20 in the drawing and the current speed conversion means 31 of the controlled object 30, the speed control system closed loop transfer function is constrained by the response characteristic of G _p (s)), and the response of the closed loop speed control system 40 is If the speed is slow, it is difficult to construct a position control system with high-speed response. Furthermore, in method (c), if the response of the closed-loop speed control system 40 is slow, the position command θ _r and the actual position θ of the controlled object 30 will deviate greatly, and as a result, the behavior of the system will be oscillated. It had some flaws that became a focus.

[Means for solving problems]

The control method for the positioning mechanism according to the present invention uses, as operational inputs, a signal obtained by amplifying the deviation between the position command obtained through a closed-loop speed control system model and an integrator and the actual position of the controlled object, and the speed By using the signal added with the command, when configuring the position control system, it is possible to improve the responsiveness of position displacement amounts such as feed amount and rotation angle, suppress vibration, and improve stopping position accuracy. It is characterized by being able to

〔Example〕

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

FIG. 1 is a block diagram showing the configuration of an embodiment of a position control system according to the present invention. The position control device 10d according to the present invention includes a speed pattern generator 11
The speed command Ω _r output from the model 16 of the closed loop speed control system 40 (its transfer function is G _p ~(s))
is input. The output of model 16 is integrator 1
2 to obtain the position command θ _r . This position command θ _r
A subtracter 13 calculates the positional deviation θ _d between the actual position θ of the controlled object 30 and the actual position _θ of the controlled object 30 . The sum of the output of the amplifier 14 and the speed command Ω _r is obtained by an adder 15 , and the output of the adder 15 becomes the operation input U _d of the drive device 20 .

The open loop speed control system 23 of the drive unit 20 is represented by a block diagram as shown in FIG. Here, k ₁ is a speed control system integral gain, k ₂ is a speed control system proportional gain, and k ₃ is a voltage-current conversion gain. That is, the speed control open loop transfer function G _v
(s) is expressed as G _v (s)=k ₃ (k ₁ +k ₂ S)/S. Therefore, the closed loop speed control system 40
The closed- _{loop transfer} function G _p (s) is: G _p (s) = k ₂ k ₃ k _t ^S + k _{1 k 3 k t /} J
+k ₁ k ₃ k _v k _t /J). In this way, the closed-loop transfer function G _p (s) of the closed-loop speed control system 40 can be calculated. In this example, the transfer function G _p (s) of the model 16 of the closed-loop speed control system was determined using an identification method such as a frequency response method. As a result, it was found that the actual closed-loop transfer function G _p ~(s) can be approximated as G _p ~(s)≈K/S+a. Therefore, the transfer function G _p (s) of the model was set as G _p ~(s)=K/S+a. Here, K and a are constants.

Therefore, the model 16 can be constructed with an analog circuit using an operational amplifier A, resistors R ₁ and R ₂ and a capacitor C, as shown in FIG. 6, for example.

Moreover, if model 16 is realized using a sample value system, the difference equation becomes x(k+1)= ^{e -aT} Calculation can be performed sequentially for each sample value. Here, u(k) is the input signal of the model 16 at time k, and x(k) is the output signal of the model 16 at time k.

Further, the speed command Ω _r outputted from the speed pattern generator 11 is generated with a plan to cause the displacement to a predetermined position within a predetermined time. this is,
For example, simple positioning of a coil feeder can be realized by generating an acceleration/deceleration pattern as shown in FIG.

Referring again to FIG. 1, the positional deviation E _d is E _d (s) = G _p /~(s) - G _p (s))・Ω _r /S+
It is expressed as G _p (s)·K ₁ . Therefore, if the transfer function G _p ~(s) of the model 16 and the closed loop transfer function G _p ~(s) of the actual closed loop speed control system 40 can be made equal,
The positional deviation E _d can be made zero. In other words, by increasing the identification accuracy of the transfer function G _p (s) of the model 16, the deviation E _d can be reduced.

On the other hand, the position deviations E _b (s) and E _c (s) in Figs. 3 and 4 are respectively E _b (s) = Ω _r /S + G _p (s) K ₁ E _c (s) = (1−G _p (s))・Ω _r /S+G _p (s
)・K ₁ . That is, which position deviation E _b
The behavior of both (s) and E _c (s) depends on the characteristics of the closed-loop transfer function G _p (s) of the closed-loop speed control system 40, and improves the response (quick response, vibration, etc.) as a position control system. In order to achieve this, compensation for phase lead, phase delay, etc. is required.

Further, in the present invention, even if a disturbance is applied to the controlled object 30, since feedback control is performed, it is possible to accurately stop the controlled object 30 at a predetermined position.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, there is an effect that high-speed positioning can be performed with high precision.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the position control system according to the present invention, FIGS. 2 to 4 are block diagrams showing the configuration of conventional position control systems, and FIG. A block diagram showing the configuration of the closed-loop speed control system of the drive device, FIG. 6 is a circuit diagram showing an example of the model in FIG. 1 configured with an analog circuit, and FIG. FIG. 3 is a diagram showing an example of a speed pattern of a speed command. 10a, 10b, 10c, 10d...Position control device, 11...Velocity pattern generator, 12...Integrator, 13...Subtractor, 14...Amplifier, 15...
... Adder, 16 ... Model of closed loop speed control system, 20 ... Drive device, 21 ... Speed feedback element, 22 ... Subtractor, 23 ... Open loop speed control system, 30 ... Controlled object, 31 ... ... Current speed conversion means, 32 ... Integrator, 40 ... Closed loop speed control system, k _t ... Torque constant, J ... Rotor inertia, S ... Laplace transform variable, K ₁ ...
Deviation gain, k _v ... speed feedback gain,
k ₁ ... Speed control system integral gain, k ₂ ... Speed control system proportional gain, k ₃ ... Voltage-current conversion gain.

Claims (1)

[Claims] 1. In a positioning control device that positions the controlled object by applying an operational input to a drive device that drives the controlled object, a speed command designed to displace the controlled object to a predetermined position within a predetermined time. means for generating a position command by inputting the speed command into a predetermined model of a speed control system including the drive device and the controlled object; 1. A control system for a positioning mechanism, comprising means for obtaining a deviation of the positional deviation, means for amplifying the positional deviation, and means for obtaining the operation input by adding the amplified positional deviation and the speed command.