JP2014021758A - Positioning control device, driving control system, positioning control method and control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the possibility of the occurrence of overshoot.SOLUTION: When a position deviation Δx between a position command Cp and a current position Yr is smaller than a first threshold β, a positioning control device 10 sets a speed command Vc to 0, and subtracts the speed command Vc and a current speed Vr to obtain a speed deviation Δv. The positioning control device 10 integrates the speed deviation Δv by an integrator 14. Afterwards, when the position deviation Δx is smaller than a second threshold α, the positioning control device 10 keeps setting the integrated value of the integrator 14 to 0. When the position deviation Δx is smaller than the second threshold α, the speed command Vc and the integrated value of the integration means 14 are set to 0, and when the current speed Vr is set to 0, the positioning control device 10 outputs a torque command Tc indicating 0.

Description

  The present invention relates to a positioning control device, a drive control system, a positioning control method, and a control device.

  A device having a drive unit such as a rotary recording device or a machine tool has a positioning control device for positioning a control target at a target position. The head positioning control device disclosed in Patent Document 1 includes a speed control unit that moves the head by speed control, a position control unit that includes an integration operation that moves the head by position control, and when the head reaches the vicinity of the target position. After switching from speed control by the speed control unit to position control by the position control unit, and after switching from the speed control unit to the position control unit, the difference between the current position of the head and the target position becomes less than the set value. An integrator control unit that once clears the integration value in the integration operation and continues the integration operation.

JP-A-11-162130

  The head positioning control apparatus described above suppresses overshoot that occurs because the integral value is large by once clearing the integral value when it is sufficiently close to the target position. However, the head positioning control device resumes the integration after clearing the integration value. For this reason, an overshoot may be caused by the integrated value after the restart. For these reasons, there is a need for a positioning control device, a drive control system, a positioning control method, and a control device that can reduce the possibility of overshoot.

  In order to achieve the above object, a positioning control device of the present invention controls a drive device that drives a control object to position the control object at a target position. A position deviation calculating means for outputting a position deviation with respect to a current position of the object, and a speed command indicating 0 when the position deviation is smaller than a first threshold, wherein the position deviation is smaller than the first threshold. If not smaller, a speed command calculating means for outputting a speed command obtained by proportionally calculating the position deviation, a speed deviation calculating means for outputting a speed deviation between the speed command and the current speed of the controlled object, and the speed deviation Integration means for integrating the integration means, integration control means for setting the integration value of the integration means to 0 when the position deviation is smaller than a second threshold value smaller than the first threshold value, the speed deviation and the integration value A torque command based on the integral value of the stage and an outputting means for outputting to the drive unit.

  In order to achieve the above object, a drive control system of the present invention includes a drive device that drives a control object, and a drive that controls the drive device and positions the control object at a target position. In the control system, the positioning control device outputs a position deviation calculating means for outputting a position deviation between the target position and the current position of the controlled object, and 0 when the position deviation is smaller than a first threshold value. When the position deviation is not smaller than the first threshold value, a speed instruction calculating means for outputting a speed instruction obtained by proportionally calculating the position deviation, the speed instruction and the control object A speed deviation calculating means for outputting a speed deviation with respect to a current speed; an integrating means for integrating the speed deviation; and if the position deviation is smaller than a second threshold smaller than the first threshold, the product An integral control means for the integral value of means 0, and an outputting means for an integrated value and the torque command based on the speed deviation and the integrating means for outputting to the drive unit.

  A positioning control method of the present invention for achieving the above object is a positioning control method of a positioning control device for controlling a driving device that drives a controlled object to position the controlled object at a target position, A step of outputting a position deviation between the target position and the current position of the controlled object, and if the position deviation is smaller than a first threshold value, a speed command indicating 0 is output, and the position deviation is the first position deviation. If not smaller than a threshold value, a step of outputting a speed command obtained by proportionally calculating the position deviation, a step of outputting a speed deviation between the speed command and the current speed of the controlled object, and a means for integrating the speed deviation And when the positional deviation is smaller than the second threshold value smaller than the first threshold value, the step of setting the integral value of the integrating means to 0, the speed deviation and the integrated value of the integrating means, Characterized in that a torque command based and a step of outputting to the drive unit.

  In order to achieve the above object, a control device according to the present invention is a control device that controls a control object based on a first parameter and a second parameter, wherein the command value of the first parameter and the first parameter First calculation means for calculating a first deviation from a parameter feedback value, and when the first deviation is smaller than a first threshold, 0 is output as a command value for the second parameter, and the first When the deviation is not smaller than the first threshold value, as the second parameter command value, a second calculation means for outputting a value obtained by proportionally calculating the first deviation, a command value for the second parameter, A third computing means for computing a second deviation from the feedback value of the second parameter; an integrating means for computing an integral value of the second deviation; and a second that has the first deviation smaller than the first threshold value. Less than threshold In this case, an integration control unit that sets the integration value calculated by the integration unit to 0, and an output unit that outputs a command value based on the second deviation and the integration value to the control target are provided. It is characterized by.

  According to the present invention, it is possible to provide a positioning control device, a drive control system, a positioning control method, and a control device that can reduce the possibility of overshoot.

FIG. 1 is a diagram illustrating a schematic configuration of the drive control system according to the first embodiment. FIG. 2 is a diagram for explaining the dead zone. FIG. 3 is a diagram illustrating the relationship between the position deviation of the positioning control device, the torque command, and time. FIG. 4 is a diagram illustrating a schematic configuration of the drive control system according to the second embodiment. FIG. 5 is a diagram illustrating a schematic configuration of the drive control system according to the third embodiment.

  An embodiment for carrying out a positioning control device according to the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following examples. The components described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the constituent elements described below can be appropriately combined.

  FIG. 1 is a diagram illustrating a schematic configuration of the drive control system according to the first embodiment. As shown in FIG. 1, the drive control system 1 includes a drive device 2, a positioning control device 10, and a host device 30. The drive device 2 includes a drive unit 3, a grinder 4, a position detection unit 5, and a speed detection unit 6.

  The drive unit 3 drives a grinder 4 that is a control object to be positioned at the target position. The drive unit 3 includes, for example, a motor driver and a motor. The output shaft of the motor transmits the output to a moving mechanism that moves the grinder 4 in a direction in which the grinder 4 is pressed against and pulled away from the construction surface. The motor driver drives the motor based on a torque command input from the positioning control device 10. The grinder 4 is a grinding machine. The grinder 4 is used for grinding the surface of the workpiece. The position detector 5 detects the current position Yr of the grinder 4 and outputs the current position Yr to the positioning control device 10. The speed detector 6 detects the current speed Vr of the grinder 4 and outputs the current speed Vr to the positioning control device 10.

  In the present embodiment, the case where the driving device 2 includes the position detection unit 5 and the speed detection unit 6 will be described, but the present invention is not limited to this. For example, the positioning control device 10 may include a position detection unit 5 and a speed detection unit 6.

  The host device 30 includes an arrival position designation unit 31 and a trajectory generation unit 32. The arrival position designation unit 31 designates the arrival position C of the grinder 4, that is, the final target position. The arrival position specifying unit 31 outputs the arrival position C to the trajectory generation unit 32. Then, the trajectory generation unit 32 generates a trajectory that reaches from the initial position of the grinder 4 to the arrival position C. The trajectory generation unit 32 divides the trajectory under a predetermined division condition, and sequentially outputs a position command Cp indicating the target position that is the end point of the divided section to the positioning control device 10. The trajectory generator 32 finally outputs a position command Cp indicating the arrival position C to the positioning control device 10. The predetermined division condition includes, for example, time and the number of divisions.

  The positioning control device 10 receives a position command Cp from the host device 30. The positioning control device 10 controls the drive unit 3 of the drive device 2 so that the grinder 4 moves to the target position indicated by the input position command Cp. The positioning control device 10 includes a subtractor 11, a speed command unit 12, a subtractor 13, an integrator 14, a multiplier 15, an adder 16, a multiplier 17, and an integration control unit 18.

  The subtractor 11 functions as a position deviation calculation means. The subtracter 11 receives the position command Cp output from the trajectory generator 32. The subtracter 11 receives the current position Yr detected by the position detector 5 as position feedback. The subtracter 11 subtracts the current position Yr from the position command Cp and outputs the subtraction result as a position deviation Δx (= Cp−Yr).

  The speed command unit 12 functions as a speed command calculation unit. The speed command unit 12 receives the position deviation Δx output by the subtractor 11. When the absolute value of the position deviation Δx is out of the dead band range described later, the speed command unit 12 executes a proportional calculation that multiplies the position deviation Δx by a proportional gain Kp, and the execution result is obtained as a speed command Vc (= ΔxKp ). The speed command unit 12 outputs a speed command Vc indicating 0 when the absolute value of the position deviation Δx is within the dead zone.

  The dead zone in the present embodiment is a range of the position deviation Δx in which the positioning control device 10 outputs the speed command Vc as 0 forcibly. That is, the dead zone is a range in which the positioning control device 10 does not integrate the speed command Vc including the unnecessary position deviation Δx that causes overshoot. The unnecessary position deviation Δx includes, for example, a position deviation Δx that occurs according to phase delay, noise, or the like.

  The dead zone in the present embodiment will be described with reference to FIG. FIG. 2 is a diagram for explaining the dead zone. In FIG. 2, the horizontal axis represents the input (position deviation Δx) of the speed command unit 12, and the vertical axis represents the output (speed command Vc) of the speed command unit 12. In the example shown in FIG. 2, the dead zone is a range where the absolute value of the positional deviation Δx is 0 to the dead zone threshold β (| Δx | <β). The dead zone threshold β is preferably set to a value smaller than the positioning accuracy specification of the positioning control device 10. For example, when the positioning accuracy specification is 0.1 mm, the dead zone threshold value β is desirably set to a value smaller than 0.1 mm. In the example shown in FIG. 2, the speed command Vc in a range outside the dead band range is expressed by a linear expression having a proportional gain Kp.

  The subtractor 13 functions as a speed deviation calculation means. The subtracter 13 receives the speed command Vc output by the speed command unit 12. The subtracter 13 receives the current speed Vr detected by the speed detector 6 as speed feedback. The subtracter 13 subtracts the current speed Vr from the speed command Vc, and outputs the subtraction result as a speed deviation Δv (= Vc−Vr).

  The integrator 14 functions as integration means. The integrator 14 receives the speed deviation Δv output from the subtractor 13. The integrator 14 receives an integration clear command from the integration control unit 18. The integrator 14 integrates the speed deviation Δv and outputs the integrated value. The integrator 14 clears the integral value to 0 and keeps the output to 0 in response to the input of the integral clear command.

  The multiplier 15 receives the integrated value output from the integrator 14. The multiplier 15 executes a proportional operation that multiplies the integral value by the integral gain Kvi, and outputs the execution result as an integral component M.

  In the present embodiment, the case where the integrator 14 and the multiplier 15 are separately configured will be described, but the present invention is not limited to this. For example, the integrator 14 may have a configuration that executes the proportional calculation in the multiplier 15. That is, the integrator 14 and the multiplier 15 may be integrally configured.

  The adder 16 functions as output means. The adder 16 receives the speed deviation Δv output by the subtractor 13. The adder 16 receives the integral component M output from the multiplier 15. The adder 16 adds the speed deviation Δv and the integral component M, and outputs the addition result.

  The multiplier 17 receives the addition result output from the adder 16. The multiplier 17 executes a proportional calculation that multiplies the addition result by a proportional gain Kvp, and outputs the execution result to the drive unit 3 as a torque command Tc. The torque command Tc includes a control amount of the motor of the drive unit 3.

  In the present embodiment, the case where the adder 16 and the multiplier 17 are configured separately will be described, but the present invention is not limited to this. For example, the adder 16 may have a configuration that executes the proportional operation in the multiplier 17. That is, the adder 16 and the multiplier 17 may be configured integrally.

  In the present embodiment, the positioning control device 10 will be described with respect to a case where the integrator 14, the multiplier 15, the adder 16, and the multiplier 17 constitute a speed control unit S that controls the speed of the driving unit 3. It is not limited to. The speed control unit S may be configured to be realized by an analog circuit, an IC chip, or the like, for example. Or speed control part S may be constituted so that CPU, DSP, etc. may realize by running a program, for example.

  The integration control unit 18 functions as integration control means. The integration controller 18 receives the position deviation Δx output by the subtractor 11. The integral control unit 18 outputs an integral clear command indicating 1 (ON) to the integrator 14 when the absolute value of the position deviation Δx is equal to or less than a predetermined integral clear threshold value α. The integral control unit 18 outputs an integral clear command indicating 0 (OFF) when the absolute value of the position deviation Δx is greater than the integral clear threshold value α. The integral clear threshold value α is smaller than the dead zone threshold value β.

  In the present embodiment, the integration control unit 18 describes a case where the integral clear command indicating “1” is continuously output to the integrator 14 when the absolute value of the position deviation Δx is equal to or less than the integral clear threshold value α. The present invention is not limited to this as long as 14 integrals can be controlled. For example, the integration control unit 18 may be configured to clear the integration value to 0 and to output to the integrator 14 an integration clear command that commands the stop of the integration. In the present embodiment, the integration control unit 18 controls the integrator 14 based on the position deviation Δx output by the subtractor 11. Therefore, it can be incorporated into a sequence in which the integrator 14 is incorporated.

  So far, the basic configuration of the drive control system 1 according to the first embodiment has been described. The operation of the positioning control device 10 will be described below with reference to FIG. FIG. 3 is a diagram showing the relationship between the position deviation, torque command, and time of the positioning control device 10. In FIG. 3, the graph G1 shows the relationship between the position deviation Δx and time, and the graph G2 shows the relationship between the torque command Tc and time.

  In the drive control system 1, when the host device 30 calculates the target position of the grinder 4, it outputs a position command Cp indicating the target position to the positioning control device 10. When the position command Cp is input, the positioning control device 10 subtracts the current position Yr from the position command Cp to obtain a position deviation Δx. As shown in the graph G1 of FIG. 3, when the position deviation Δx is larger than the positioning accuracy specification P, the positioning control device 10 obtains a speed command Vc obtained by proportionally calculating the position deviation Δx. When the positioning control device 10 obtains the speed deviation Δv obtained by subtracting the current speed Vr from the speed command Vc, the positioning control apparatus 10 integrates the speed deviation Δv. When the positioning control device 10 obtains the torque command Tc obtained by adding the speed deviation Δv and the integral component M, the positioning control device 10 outputs the torque command Tc to the drive unit 3. Then, the drive unit 3 drives the motor based on the torque command Tc, and moves the grinder 4 toward the target position.

  When the position deviation Δx becomes smaller than the positioning accuracy specification P and the dead zone threshold β at time t1, the positioning control device 10 forcibly sets the speed command Vc to zero. At this time, the current speed Vr is not zero. Therefore, the positioning control device 10 integrates the speed deviation Δv obtained based on the speed command Vc to obtain the torque command Tc. The positioning control device 10 outputs a torque command Tc that is not 0 to the drive unit 3 as shown by a graph G2 in FIG.

  Thereafter, as time passes, as shown in FIG. 3, the value of the position deviation Δx gradually decreases, and the value of the torque command Tc also gradually decreases. Then, when the position deviation Δx becomes equal to or less than the integral clear threshold value α at time t2, the positioning control device 10 clears the integral value of the integrator 14 to zero. In this case, the speed command Vc is also 0 due to the dead zone, but the current speed Vr is not 0. Therefore, the positioning control device 10 outputs a torque command Tc based on the current speed Vr to the drive unit 3.

  Thereafter, the position deviation Δx gradually approaches 0, but is less than or equal to the integral clear threshold value α. Therefore, the positioning control device 10 continues to clear the integral value of the integrator 14 to 0, and a torque command based on the current speed Vr. Continue to output Tc to the drive unit 3. Thereafter, at time t3, the drive unit 3 positions the grinder 4 at the target position based on the torque command Tc. In this case, since the input current speed Vr becomes 0, the positioning control device 10 obtains a torque command Tc indicating 0 because the speed deviation Δv and the integral value are 0. Therefore, after the drive unit 3 positions the grinder 4 at the target position, the positioning control device 10 outputs a torque command Tc indicating 0 to the drive unit 3.

  As described above, when the position deviation Δx becomes smaller than the dead zone threshold (first threshold) β, the positioning control device 10 sets the speed command Vc to 0 and the speed deviation obtained based on the speed command Vc. Integrate Δv. Therefore, since the positioning control device 10 does not reflect the unnecessary speed command Vc that causes overshooting in the integrated value, it is possible to prevent the unnecessary speed command Vc from being included in the torque command Tc. Further, the positioning control device 10 continues to set the integral value to 0 when the position deviation Δx is smaller than the integral clear threshold (second threshold) α. Therefore, the positioning control device 10 sets the torque command Tc to 0 when the speed feedback becomes 0 because the speed command Vc and the integrated value become 0 when the position deviation Δx becomes smaller than the integral clear threshold value α. be able to. Therefore, the positioning control device 10 continues to clear the integral element of the speed control to 0, so that the torque command Tc whose phase is delayed with respect to the target position is not output, and the possibility of overshooting is reduced. it can. Furthermore, since the positioning control device 10 can reduce the possibility of overshooting, it can reduce the possibility of stick-slip that repeats stationary and overshooting in a low speed range.

  Further, as shown in FIG. 3, the positioning control device 10 may set the integral clear threshold value α and the dead zone threshold value β within the range of the positional deviation Δx indicated by the positioning accuracy specification P. Thus, each threshold value can be designed intuitively.

  Thereafter, as shown in the graph G1 of FIG. 3, when the spiked noise or the like is superimposed on the position deviation Δx at time t4 and the position deviation Δx exceeds the integral clear threshold value α and enters the dead zone, the positioning control device 10 Then, the integration of the speed deviation Δv is resumed. However, when the position deviation Δx is within the dead zone, the positioning control device 10 has the speed deviation Δv of 0 and the integrated value of the speed deviation Δv remains 0, so the torque command Tc is also 0. As a result, the positioning control device 10 outputs a torque command Tc indicating 0 to the drive unit 3 unless the position deviation Δx is equal to or greater than the dead zone threshold value β. Therefore, the positioning control device 10 can maintain the grinder 4 in a stopped state even if a positional deviation Δx that is equal to or less than the dead zone threshold value β occurs while the torque command Tc indicating 0 is being output.

  Thereafter, when a new position command Cp is input, the positioning control device 10 obtains the speed deviation Δv because the position deviation Δx becomes larger than the dead zone threshold value β and the integral clear threshold value α, and an integrator for this speed deviation Δv. The integration by 14 is resumed.

  The drive control system 1A according to the second embodiment will be described below with reference to FIG. FIG. 4 is a diagram illustrating a schematic configuration of a drive control system 1A according to the second embodiment. In order to simplify the description of the drive control system 1A, the same components as those in FIG.

  As shown in FIG. 4, the drive control system 1A includes a drive device 2, a positioning control device 10A, and a host device 30A.

  The drive device 2 includes a drive unit 3, a grinder 4, a position detection unit 5, and a speed detection unit 6.

  The higher-level device 30 </ b> A includes an arrival position designation unit 31 and a trajectory generation unit 32. The host device 30A outputs the arrival position C output by the arrival position specifying unit 31 to the positioning control device 10A. The trajectory generation unit 32 outputs the position command Cp to the positioning control device 10A.

  As shown in FIG. 4, the positioning control device 10A includes a subtractor 11, a speed command unit 12, a subtractor 13, an integrator 14, a multiplier 15, an adder 16, a multiplier 17, and an integration. A control unit 18, a subtracter 19, a detection unit 20, and an AND gate 21 are included.

  The integrator 14 receives the speed deviation Δv output from the subtractor 13. The integrator 14 receives an integration clear command from the AND gate 21. The integrator 14 integrates the speed deviation Δv and outputs the integrated value. The integrator 14 clears the integral value to 0 and keeps the output to 0 in response to the input of the integral clear command.

  The integral control unit 18 outputs an integral clear command indicating 1 (ON) to the AND gate 21 when the absolute value of the position deviation Δx is equal to or smaller than a predetermined integral clear threshold value α. When the absolute value of the position deviation Δx is larger than the integral clear threshold value α, an integral clear command indicating 0 (OFF) is output to the AND gate 21.

  The subtracter 19 receives the arrival position C designated by the arrival position designation unit 31 of the host device 30A. The subtracter 19 receives the current position Yr detected by the position detector 5 as position feedback. The subtracter 19 subtracts the current position Yr from the arrival position C, and outputs the subtraction result as a position deviation Δy (= C−Yr).

  The detection unit 20 functions as a detection unit. The detection unit 20 receives the position deviation Δy output by the subtractor 19. The detection unit 20 detects a positional deviation Δy that is equal to or smaller than the detection threshold γ. In the present embodiment, the detection threshold γ is set to detect that the current position Yr is in the vicinity of the arrival position C based on the position deviation Δy. When detecting the position deviation Δy that is equal to or smaller than the detection threshold γ, the detection unit 20 outputs an integral clear command indicating 1 (ON) to the AND gate 21 because the current position Yr is in the vicinity of the arrival position C. If the detection unit 20 detects a position deviation Δy that is greater than the detection threshold γ, the current position Yr is not in the vicinity of the arrival position C, and therefore outputs an integral clear command indicating 0 (OFF) to the AND gate 21.

  The AND gate 21 receives the integration clear command output by the integration control unit 18. The AND gate 21 receives the integral clear command output by the detection unit 20. The AND gate 21 outputs an integration clear command indicating 1 (ON) to the integrator 14 when an integration clear command indicating 1 is input from both the integration control unit 18 and the detection unit 20. The AND gate 21 is 0 (OFF) when an integral clear command indicating 1 is input only from either the integration control unit 18 or the detection unit 20 or when an integral clear command indicating 0 is input from both. Is output to the integrator 14.

  The positioning control device 10A clears the integration value of the integrator 14 to 0 when the current position of the grinder 4 is in the vicinity of the arrival position C and when the position deviation Δx is equal to or less than the integration clear threshold value α. Therefore, for example, even if the positioning controller 10A accidentally catches up with the target position during the movement of the grinder 4 and the position deviation Δx becomes 0, the integrated value of the integrator 14 is not cleared unless it is near the arrival position C. . Therefore, since the positioning control device 10A clears the integrated value in the vicinity of the arrival position C where it is desired to suppress overshoot, the grinder 4 can be prevented from temporarily stopping during movement.

  In this embodiment, the case where the integration control unit 18, the subtractor 19, the detection unit 20, and the AND gate 21 are combined to control the integration clear of the integrator 14 has been described, but the present invention is not limited to this. For example, the integration control unit 18 may have a configuration corresponding to each function of the detection unit 20 and the AND gate 21. Alternatively, the integration control unit 18 may have a configuration corresponding to the function of the AND gate 21.

  Next, the operation of the positioning control apparatus 10A according to the second embodiment will be described.

  In the drive control system 1A, when the arrival position C is specified, the host apparatus 30A outputs the arrival position C to the positioning control apparatus 10A. When the host device 30A calculates the target position of the grinder 4 based on the current position Yr and the arrival position C, the host device 30A outputs a position command Cp indicating the target position to the positioning control device 10A.

  When the arrival position C output by the host device 30A is input, the positioning control apparatus 10A subtracts the current position Yr from the arrival position C to obtain a position deviation Δy. When the position deviation Δy is larger than the detection threshold γ, the positioning control device 10A detects that the grinder 4 has not reached the vicinity of the arrival position C. Therefore, the positioning control device 10 </ b> A is in a state where the AND gate 21 prevents the integration control unit 18 from clearing the integration value of the integrator 14.

  The positioning controller 10A subtracts the current position Yr from the position command Cp to obtain a position deviation Δx. When the position deviation Δx is larger than the positioning accuracy specification P, the positioning control device 10A obtains a speed command Vc obtained by proportionally calculating the position deviation Δx. When the positioning controller 10A obtains the speed deviation Δv obtained by subtracting the current speed Vr from the speed command Vc, the positioning control apparatus 10A integrates the speed deviation Δv. When positioning controller 10A obtains torque command Tc by adding speed deviation Δv and integral component M, it outputs torque command Tc to drive unit 3. Then, the drive unit 3 drives the motor based on the torque command Tc, and moves the grinder 4 toward the target position.

  The positioning controller 10A subtracts the current position Yr from the arrival position C to obtain a position deviation Δy. When the position deviation Δy is equal to or smaller than the detection threshold γ, the positioning control device 10A detects that the grinder 4 has reached the vicinity of the arrival position C. Therefore, in the positioning control device 10A, the AND gate 21 does not prevent the integration control unit 18 from clearing the integration value of the integrator 14.

  Thereafter, when the position deviation Δx becomes smaller than the positioning accuracy specification P and the dead zone threshold β, the positioning control device 10A forcibly sets the speed command Vc to 0. At this time, the current speed Vr is not zero. Therefore, the positioning control device 10A integrates the speed deviation Δv obtained based on the speed command Vc to obtain the torque command Tc. The positioning control device 10 </ b> A outputs a torque command Tc that is not 0 to the drive unit 3.

  Thereafter, as time elapses, the value of the position deviation Δx gradually decreases, and the value of the torque command Tc also gradually decreases. At time t2, the position deviation Δx becomes equal to or less than the integral clear threshold value α, the position deviation Δy becomes equal to or less than the detection threshold value γ, and the grinder 4 has reached the vicinity of the arrival position C. Therefore, the positioning control device 10A clears the integral value of the integrator 14 to zero. In this case, the speed command Vc is also 0 due to the dead zone, but the current speed Vr is not 0. Therefore, the positioning control device 10A outputs a torque command Tc based on the current speed Vr to the drive unit 3.

  Thereafter, the position deviation Δx gradually approaches 0, but is below the integral clear threshold α, so the positioning control device 10A continues to clear the integral value of the integrator 14 to 0, and a torque command based on the current speed Vr. Continue to output Tc to the drive unit 3. Thereafter, the drive unit 3 positions the grinder 4 at the target position based on the torque command Tc. In this case, since the input current speed Vr is 0, the positioning control device 10A has a speed deviation Δv and an integral value of 0, and obtains a torque command Tc indicating 0. Therefore, after the drive unit 3 positions the grinder 4 at the target position, the positioning control device 10A outputs a torque command Tc indicating 0 to the drive unit 3.

  The drive control system 1B according to the third embodiment will be described below with reference to FIG. FIG. 5 is a diagram illustrating a schematic configuration of the drive control system 1B according to the third embodiment. In order to simplify the description of the drive control system 1B, the same components as those in FIG.

  As shown in FIG. 5, the drive control system 1B includes a drive device 2, a positioning control device 10B, and a host device 30.

  The drive device 2 includes a drive unit 3, a grinder 4, a position detection unit 5, and a speed detection unit 6. The host device 30 includes an arrival position designation unit 31 and a trajectory generation unit 32.

  As shown in FIG. 5, the positioning control device 10B includes a subtractor 11, a speed command unit 12, a subtractor 13, an integrator 14, a multiplier 15, an adder 16B, a multiplier 17, and an integration. The controller 18, the multiplier 22, and the subtracter 23 are included.

  The multiplier 22 functions as a first speed command calculation unit of the speed command calculation means. The multiplier 22 receives the position deviation Δx output from the subtractor 11. The multiplier 22 executes a proportional calculation for multiplying the positional deviation Δx by the proportional gain Kp, and outputs the execution result to the subtracter 23 as a first speed command Vc1 (= ΔxKp). The proportional gain Kp is set to the same value as the proportional gain Kp of the speed command unit 12.

  In the present embodiment, the case where the speed command unit 12 and the multiplier 22 are separated will be described, but the present invention is not limited to this. For example, the speed command unit 12 may have a configuration corresponding to the multiplier 22. In this case, when the position deviation Δx becomes larger than the dead zone threshold β, the speed command unit 12 outputs the speed command Vc indicating 0 to the subtractor 13 and outputs the first speed command Vc1 to the subtractor 23. Configured to do.

  The subtracter 23 receives the first speed command Vc1 output from the multiplier 22. The subtracter 23 receives the current speed Vr detected by the speed detector 6 as speed feedback. The subtracter 23 subtracts the current speed Vr from the first speed command Vc1, and outputs the subtraction result as a first speed deviation Δv1 (= Vc1−Vr). That is, the subtractor 23 outputs the first speed deviation Δv1 that is not affected by the dead zone to the adder 16B.

  The adder 16B receives the first speed deviation Δv1 output from the subtracter 23. The adder 16B receives the integral component M output from the multiplier 15. The adder 16B adds the first speed deviation Δv1 and the integral component M, and outputs the addition result to the multiplier 17. As described above, the adder 16B is different from the adder 16 of the first embodiment in that the integral component M is added to the first speed deviation Δv1 that is not affected by the dead zone.

  When the position deviation Δx is smaller than the integral clear threshold value α, the positioning control device 10B does not set the first speed command Vc1 to 0, but subtracts the first speed command Vc1 and the current speed Vr to obtain the first speed deviation. Δv1 is obtained. The positioning control device 10B outputs a torque command Tc obtained by adding the integral component M based on the integral value of the speed deviation Δv and the first speed deviation Δv1. Therefore, since the positioning control device 10B continues the speed control based on the proportional element even if the position deviation Δx becomes smaller than the integral clear threshold value α, the performance of the proportional control can be improved even if a dead zone is provided. For example, if the positioning accuracy specification P of the positioning control device 10B is 0.1 mm, the positioning control device 10B can exhibit its performance if the designer designs 10 times that is, that is, 0.01 mm.

  Next, the operation of the positioning control device 10B according to the third embodiment will be described.

  In the drive control system 1B, when the host device 30 calculates the target position of the grinder 4, the host device 30 outputs a position command Cp indicating the target position to the positioning control device 10B. When the position command Cp is input, the positioning control device 10B subtracts the current position Yr from the position command Cp to obtain a position deviation Δx. The positioning control device 10B proportionally calculates the position deviation Δx, and subtracts the current speed Vr from the calculation result to obtain a first speed deviation Δv1. In parallel with this, when the position deviation Δx is larger than the positioning accuracy specification P, the positioning control device 10B obtains a speed command Vc by proportionally calculating the position deviation Δx. When the positioning control device 10B obtains the speed deviation Δv obtained by subtracting the current speed Vr from the speed command Vc, the positioning control apparatus 10B integrates the speed deviation Δv. In this case, since the position deviation Δx is outside the range of the dead zone, the first speed deviation Δv1 and the speed deviation Δv have the same value. When the positioning control device 10B obtains the torque command Tc obtained by adding the first speed deviation Δv1 and the integral component M, the positioning control device 10B outputs the torque command Tc to the drive unit 3. Then, the drive unit 3 drives the motor based on the torque command Tc, and moves the grinder 4 toward the target position.

  Thereafter, when the position deviation Δx becomes smaller than the positioning accuracy specification P and the dead zone threshold β, the positioning control device 10B forcibly sets the speed command Vc to 0 and obtains the first speed command Vc1. At this time, since the current speed Vr is not 0, the positioning control device 10B obtains the first speed deviation Δv1. In this case, since the speed command Vc becomes 0 due to the dead zone, the positioning control device 10B integrates the speed deviation Δv obtained based on the current speed Vr. Then, the positioning control device 10B outputs a torque command Tc, which is not 0, obtained by adding the first speed deviation Δv1 and the integral component M to the drive unit 3.

  Thereafter, as time elapses, the value of the position deviation Δx gradually decreases, and the value of the torque command Tc also gradually decreases. When the position deviation Δx becomes equal to or less than the integral clear threshold value α, the positioning control device 10B clears the integral value of the integrator 14 to zero. In this case, since the position deviation Δx is not 0, the positioning control device 10B obtains a first speed deviation Δv1 that is not 0. The positioning control device 10B outputs a torque command Tc based on the first speed deviation Δv1 to the drive unit 3.

  Thereafter, the position deviation Δx gradually approaches 0, but is less than or equal to the integral clear threshold value α. Therefore, the positioning control device 10B continues to clear the integral value of the integrator 14 to 0, and is based on the first speed deviation Δv1. The torque command Tc is continuously output to the drive unit 3. Thereafter, the drive unit 3 positions the grinder 4 at the target position based on the torque command Tc. In this case, since the input current position Yr and current speed Vr become 0, the positioning control device 10B obtains a torque command Tc indicating 0 because the first speed deviation Δv1 becomes 0. Therefore, after the drive unit 3 positions the grinder 4 at the target position, the positioning control device 10B outputs a torque command Tc indicating 0 to the drive unit 3.

  In the above-described embodiments, the case where the PI control is used as the speed control of the positioning control devices 10, 10A, and 10B has been described. However, the present invention is not limited to this. The speed control method may be configured to include, for example, PID control, another characteristic improvement filter, and the like.

  In the above-described embodiment, the positioning control devices 10, 10A, and 10B have been described with respect to the case where the integral value of the integrator 14 is instantaneously cleared to 0 when the position deviation Δx is equal to or less than the integral clear threshold value α. It is not limited to. The positioning control devices 10, 10 </ b> A, and 10 </ b> B may be configured to gradually decrease the integrated value of the integrator 14 instead of instantaneously clearing it to zero.

  For example, the integration control unit 18 of the positioning control devices 10, 10 </ b> A, and 10 </ b> B outputs a command indicating stepwise clearing of the integration value to the integrator 14. The integrator 14 sets the integration value when a command is input or when the position deviation Δx is equal to or less than the integration clear threshold value α to 100%, and the integration value is changed from 100% to 0% at a predetermined time. Decrease in multiple steps.

  In the drive control systems 1, 1 </ b> A, and 1 </ b> B, when the drive unit 3 has a transmission structure of a speed reducer and a ball screw, those elements are microscopically bent to transmit force. In this situation, if the driving torque of the driving unit 3 is suddenly reduced to 0, the bending reaction force becomes a disturbance and acts on the motor, and the position deviation Δx may increase. In this case, the position deviation Δx that has been smaller than the dead zone threshold β becomes equal to or greater than the dead zone threshold β again, and when the positioning control devices 10, 10A, and 10B resume the integration of the speed deviation Δv, the behavior of the grinder 4 is unexpected. There is a risk of movement. In the case of such a configuration, it is possible to reduce the influence of the bending reaction force by clearing the integral value of the integrator 14 so as to gradually decrease. As a result, the behavior of the grinder 4 in the drive control systems 1, 1A, 1B can be converged stably.

  In the above-described embodiment, the integration control unit 18 clears the integration of the integrator 14 when the position deviation Δx is larger than the integration clear threshold value α in a state where the integration value of the integrator 14 is cleared to zero. Although the case of resuming has been described, the present invention is not limited to this. For example, the integration control unit 18 causes the integrator 14 to resume the integration when the position deviation Δx exceeds the integration clear threshold value α continuously for a certain time, and the position deviation Δx continues for a certain time continuously. If α is not exceeded, the integrator 14 may be configured not to resume the integration.

  In the embodiment described above, the positioning control devices 10, 10 </ b> A, and 10 </ b> B have been described as being applied to the drive control systems 1, 1 </ b> A, and 1 </ b> B that automatically control the grinder 4, but are not limited thereto. The positioning control devices 10, 10A, 10B may be applied to devices that require precise positioning by a motor or the like. Devices that require precise positioning include, for example, rotational recording devices such as hard disk devices and magnetic disk devices, and drive control devices for various machine tools.

  Embodiments 2 and 3 described above may be combined. For example, the positioning control device 10A of the drive control system 1A is configured to have a configuration of the positioning control device 10B for continuing the proportional control of the position deviation Δx when the position deviation Δx becomes smaller than the integral clear threshold value α. May be.

DESCRIPTION OF SYMBOLS 1, 1A, 1B Drive control system 2 Drive apparatus 3 Drive part 4 Grinder 5 Position detection part 6 Speed detection part 10, 10A, 10B Positioning control apparatus 11, 13, 19, 23 Subtractor 12 Speed command part 14 Integrator 15, 17, 22 Multiplier 16, 16B Adder 18 Integral control unit 20 Detection unit 21 AND gate 30, 30A, 30B Host device 31 Arrival position designation unit 32 Trajectory generation unit

Claims (8)

In a positioning control device for controlling a drive device that drives a control object to position the control object at a target position,
Position deviation calculating means for outputting a position deviation between the target position and the current position of the controlled object;
When the position deviation is smaller than the first threshold value, a speed command indicating 0 is output, and when the position deviation is not smaller than the first threshold value, a speed command that outputs a speed command obtained by proportionally calculating the position deviation is output. Command calculation means;
A speed deviation calculating means for outputting a speed deviation between the speed command and a current speed of the controlled object;
Integrating means for integrating the speed deviation;
Integration control means for setting the integration value of the integration means to 0 when the positional deviation is smaller than a second threshold value smaller than the first threshold value;
A positioning control device comprising: output means for outputting a torque command based on the speed deviation and an integral value of the integrating means to the driving device. The speed command calculation means includes a first speed command calculation unit that outputs a first speed command obtained by proportionally calculating the position deviation,
The speed deviation calculating means calculates the speed deviation between the first speed command output by the first speed command calculating unit and the current speed of the control object when the position deviation is smaller than the first threshold. The positioning control apparatus according to claim 1, wherein the positioning control apparatus outputs the output to output means. Detection means for detecting that the current position of the control object is in the vicinity of the arrival position;
When the detection means detects that the current position is in the vicinity of the arrival position, and the position deviation is smaller than the second threshold value, the integration control means calculates the integration value of the integration means. The positioning control device according to claim 1, wherein the positioning control device is set to zero.   The positioning control apparatus according to claim 1, wherein the integration control unit gradually sets the integration value to zero.   5. The positioning control device according to claim 1, wherein the first threshold value is set within a range of the position deviation indicated by a positioning accuracy specification of the positioning control device. A drive control system comprising: a drive device that drives a control object; and a positioning control device that controls the drive device to position the control object at a target position,
The positioning control device includes:
Position deviation calculating means for outputting a position deviation between the target position and the current position of the controlled object;
When the position deviation is smaller than the first threshold value, a speed command indicating 0 is output, and when the position deviation is not smaller than the first threshold value, a speed command that outputs a speed command obtained by proportionally calculating the position deviation is output. Command calculation means;
A speed deviation calculating means for outputting a speed deviation between the speed command and a current speed of the controlled object;
Integrating means for integrating the speed deviation;
Integration control means for setting the integration value of the integration means to 0 when the positional deviation is smaller than a second threshold value smaller than the first threshold value;
An output means for outputting a torque command based on the speed deviation and an integral value of the integrating means to the driving device. A positioning control method for a positioning control device for controlling a drive device that drives a control object to position the control object at a target position,
Outputting a position deviation between the target position and the current position of the controlled object;
When the position deviation is smaller than the first threshold, a speed command indicating 0 is output, and when the position deviation is not smaller than the first threshold, a speed command obtained by proportionally calculating the position deviation is output. When,
Outputting a speed deviation between the speed command and the current speed of the controlled object;
Integrating the speed deviation by an integrating means;
When the positional deviation is smaller than a second threshold value smaller than the first threshold value, the step of setting the integral value of the integrating means to 0;
And a step of outputting a torque command based on the speed deviation and an integral value of the integrating means to the driving device. In the control device that controls the control object based on the first parameter and the second parameter,
First computing means for computing a first deviation between the command value of the first parameter and the feedback value of the first parameter;
When the first deviation is smaller than the first threshold, 0 is output as the command value of the second parameter, and when the first deviation is not smaller than the first threshold, the second parameter A second calculation means for outputting a value obtained by proportionally calculating the first deviation as a command value;
Third computing means for computing a second deviation between the command value of the second parameter and the feedback value of the second parameter;
Integrating means for calculating an integral value of the second deviation;
Integration control means for setting the integration value calculated by the integration means to 0 when the first deviation is smaller than a second threshold value smaller than the first threshold value;
A control device comprising: output means for outputting a command value based on the second deviation and the integral value to the control object.

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