JP2011100203A - Position control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress overshoot and to reduce cycle time, in a position control device for moving and stopping a machine to be controlled at a target position. <P>SOLUTION: A feedforward control block 27a has a function of outputting a value obtained by multiplying a position command value from a position command block 21 by a feedforward gain set and output by a feedforward setting means 41, as a new correction amount. When the position control device 40 starts positioning control operation, the feedforward setting means 41 monitors the change of pulse frequency while determining a speed command operation value based on the change of pulse frequency included in a pulse train type position command value from a position command block 21, and sets a smaller feedforward gain to the feedforward control block 27a when the speed command operation value is smaller than a predetermined switching set value. Overshoot at the end of positioning is thereby suppressed, and cycle time from the start of positioning to the end can be reduced. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a position control device for moving a control target machine to a target position and stopping it, and more particularly to a position control device configured to suppress vibration of the control target machine due to inertial force at the time of stop.

  FIG. 19 is a schematic conceptual configuration diagram of this type of control target machine.

  The target machine 10 includes a heavy object 11, an arm 12, a slide moving unit 13, a slide rail unit 14, a feed screw 15, a coupling 16, a motor 17, a motor encoder 18, and a position control device. Any one of 20, 30, 40, 50, 60, 70, 80, and 90 is provided. Among these, the heavy object 11, the arm 12, the slide moving unit 13, the slide rail unit 14, the feed screw 15, and the coupling 16 are included as controlled machines.

  In FIG. 19, the slide rail portion 14 restrains the slide moving portion 13 to move only in the left and right moving directions shown in the figure. Furthermore, the contact portion between the slide rail portion 14 and the slide moving portion 13 has low friction so that the slide moving portion 13 can move smoothly on the slide rail portion 14. The output shaft of the motor 17 is connected to a feed screw 15 via a coupling 16, and the feed screw 15 is screwed into a screw portion (not shown) attached to the slide moving portion 13.

  That is, when the motor 17 rotationally drives the feed screw 15 by positioning control according to the position command value from any one of the position control devices, the slide moving unit 13 moves in the horizontal direction shown in the drawing.

  A long arm 12 is attached to the slide moving unit 13 in which such positioning control is performed, and a heavy object 11 is attached to the tip of the arm 12. Therefore, positioning of the heavy object 11 at the tip of the arm 12 is also controlled by position control of the slide moving unit 13.

  In the configuration shown in FIG. 19, even when the slide moving unit 13 stops at the target position, the heavy object 11 at the tip of the arm 12 deflects the arm 12 by its own inertial force and advances ahead of the command position. It is known that even after the slide moving unit 13 stops at the target position, it may vibrate without stopping immediately.

  FIG. 20 is a circuit configuration diagram of a conventional position control device 20 having a function of suppressing the above-described vibration phenomenon, and is a circuit configuration disclosed in Patent Document 1 below.

  The position control device 20 includes a position command block 21, a position adjuster 22, a speed adjuster 28, and a torque adjuster 29.

  In FIG. 20, a position command block 21 outputs a position command value in a pulse train format for the slide moving unit 13 to move to a target position, and the number of pulses commands the amount of movement in this pulse train format position command value. The frequency instructs the moving speed at that time (that is, the moving amount of the position per unit time becomes a command value corresponding to the speed).

  In the position adjuster 22 including the subtractor 23, integrator 24, adjuster 25, adder 26, and feedforward control block 27, a pulse train detection signal is instructed from the motor encoder 18 attached to the output shaft of the motor 17. In order to match the position command value, an adjustment operation using the subtractor 23, the integrator 24, and the adjuster 25 is performed, and the output is sent to the speed adjuster 28 via the adder 26 as a speed command value. It is done.

  At this time, the feedforward control block 27 obtains a correction amount obtained by multiplying the movement amount of the position per unit time of the position command value from the position command block 21 by a predetermined feedforward gain, and this correction amount and the controller 25. Are added by the adder 26, and the added value is sent to the speed adjuster 28 as a new speed command value.

  In the speed adjuster 28, an adjustment operation is performed so that the detected speed value of the motor 17 based on the pulse train detection signal from the motor encoder 18 matches the speed command value, and the output is used as the torque command value. Sent to.

  In the torque adjuster 29, the motor 17 is driven via a semiconductor power converter such as an inverter built in the torque adjuster 29 according to the torque command value, and the slide moving unit 13 of the target machine 10 is moved to a predetermined position. Positioning control is performed to stop the operation.

  FIG. 21 is a circuit configuration diagram of a conventional position control device different from the position control device 20 shown in FIG. 20, and components having the same functions as those shown in FIG. .

  The position control device 30 includes a position command block 31, a position adjuster 32, an integrator 38, a speed adjuster 28, and a torque adjuster 29.

  In FIG. 21, the position command block 31 outputs a position command value in a data format for the slide moving unit 13 to move to the target position. In the position command value in this data format, the data value commands the movement amount, Data changes command the moving speed at that time.

  In the position adjuster 32 including the subtractor 33, the adjuster 34, the adder 35, the differentiator 36, and the feedforward control block 37, the integration of the pulse train detection signal from the motor encoder 18 attached to the motor 17 is performed by the adder 38. In order to make the movement amount detection value, which is a value, coincide with the position command value commanded from the position command block 31, an adjustment operation using the subtractor 33 and the adjuster 34 is performed, and the output is the speed command value. It is sent to the speed adjuster 22 via the adder 35.

  At this time, the differentiator 36 and the feedforward control block 37 obtain a correction amount obtained by multiplying the differential value of the position command value from the position command block 31 by a predetermined feedforward gain. The speed command value is added by the adder 35, and this added value is sent to the speed controller 28 as a new speed command value.

JP 2003-76426 A

  In the conventional position control devices 20 and 30, if the feed forward gains in the feed forward control blocks 27 and 37 forming the position adjusters 22 and 32 are set too large, the overshoot at the end of positioning becomes large. It is known that if the feed forward gain is set too small, the required time (also referred to as cycle time) from the start to the end of positioning becomes longer.

  Especially when the arm of the machine to be controlled is long and its rigidity is low, when the proportional gain of the adjusters 25 and 34 forming the position adjusters 22 and 32 cannot be set large, the positioning performance in this state is the setting of the feed forward gain. Since it greatly depends on the value, the conventional fixed feedforward gain setting value has a problem that it is impossible to achieve both suppression of overshooting at the end of positioning and reduction of cycle time.

  An object of the present invention is to provide a position control device that solves the above problems.

  In the first aspect of the present invention, when positioning control is performed based on a position command value commanded to move the controlled machine to a target position and stop, the output value of the position adjustment calculation operation for this positioning control is performed. A correction amount obtained by multiplying the position command value by the feedforward gain is added to the position control device that drives and controls the machine to be controlled based on the added value. Feed-forward gain setting means for changing in a step function manner up to a set value is provided.

  According to a second aspect of the present invention, the position control device includes feedforward gain setting means for changing the set value of the feedforward gain to a new set value in a ramp function.

A third invention is the position control device of the first or second invention,
The feedforward gain setting means is characterized in that when the speed command calculation value based on the position command value is smaller than a predetermined switching setting value, the feedforward gain setting value is made smaller.

4th invention is the position control apparatus of the said 1st or 2nd invention,
The feedforward gain setting means is characterized in that when the speed command calculation value based on the position command value is smaller than a predetermined switching setting value in a deceleration state, the feedforward gain setting value is made smaller.

A fifth invention is the position control device of the first or second invention,
The feedforward gain setting means reduces the set value of the feedforward gain when the calculated amount of movement based on the position command value exceeds a switching set value that is smaller than the target position by a predetermined value. Features.

  According to the present invention, by changing the set value of the feedforward gain corresponding to the speed command calculation value or the movement amount calculation value based on the position command value, the overshoot can be suppressed and the cycle time at the end of positioning. It is possible to achieve both shortening.

1 is a circuit configuration diagram of a position control device showing a first embodiment of the present invention. Waveform diagram explaining the operation of FIG. Waveform diagram explaining the operation of FIG. Waveform diagram explaining the operation of FIG. Waveform diagram explaining the operation of FIG. Circuit configuration diagram of a position control apparatus showing a second embodiment of the present invention Waveform diagram for explaining the operation of FIG. Waveform diagram for explaining the operation of FIG. Waveform diagram for explaining the operation of FIG. Waveform diagram for explaining the operation of FIG. Circuit configuration diagram of a position control apparatus showing a third embodiment of the present invention. Circuit configuration diagram of a position control apparatus showing a fourth embodiment of the present invention. Waveform diagram explaining the operation of FIGS. Waveform diagram explaining the operation of FIGS. Circuit configuration diagram of a position control device showing a fifth embodiment of the present invention Circuit configuration diagram of a position control apparatus showing a sixth embodiment of the present invention. Waveform diagram explaining the operation of FIGS. Waveform diagram explaining the operation of FIGS. Schematic conceptual configuration diagram of the machine to be controlled Circuit configuration diagram of position control device showing conventional example Circuit configuration diagram of position control device showing conventional example

<Example>
FIG. 1 is a circuit diagram of a position control apparatus showing a first embodiment of the present invention. In this figure, components having the same functions as those of the conventional position control apparatus 20 shown in FIG. A description thereof will be omitted here.

  The position control device 40 includes a position adjuster 22a in which the feedforward control block 27 is changed to a feedforward control block 27a instead of the conventional position adjuster 22.

  This feedforward control block 27a is adapted to feedforward setting means 41-41 for a command value (speed command calculation value) corresponding to a speed based on the amount of movement of the position command value from the position command block 21 per unit time. A value obtained by multiplying the feed forward gain set and output at any of 44 is output as a new correction amount.

  FIG. 2 is a waveform diagram for explaining the operation when the feedforward setting means 41 is used in the position control device 40 shown in FIG.

That is, when the position control device 40 starts a positioning control operation, the feedforward setting means 41 obtains a speed command calculation value based on a change in pulse frequency included in the position command value in the pulse train format from the position command block 21. the change was monitored, as shown in FIG. 2, to set a smaller feed forward gain of the speed command calculated value to the feedforward control block 27a is a small time T ₀ previously than the predetermined switching換設value. Further, while the speed command calculated value of a predetermined switching換設value greater than the time T ₀ ~ time T ₁ is set larger feedforward gain to the feed forward control block 27a, defined further speed command calculated value in advance It was small time T ₁ after than switching換設value set smaller feedforward gain to the feed forward control block 27a. By changing the feedforward gain in accordance with the speed command calculation value as described above, the position control device 40 using the feedforward setting means 41 suppresses overshoot at the end of positioning and starts and ends the positioning. The cycle time can be shortened.

  FIG. 3 is a waveform diagram for explaining the operation when the feedforward setting means 42 is used in the position control device 40 shown in FIG.

That is, when the position control device 40 starts the positioning control operation, the feedforward setting means 42 obtains a speed command calculation value based on a change in pulse frequency included in the position command value in the pulse train format from the position command block 21. monitoring the change, as shown in FIG. 3, is set smaller feedforward gain of the speed command calculated value to the feedforward control block 27a is in the first switching換設value smaller than the time T ₁ before a predetermined, also the period from time T ₁ ~ time T _2, to the speed command calculated value reaches a second switching換設value previously determined increases the feed-forward gain of the feedforward control block 27a by ramp function like, further, the during the speed command calculated value is a time T ₂ ~ time T ₃ in the state exceeding the second switching換設value is Fidofu The feed forward gain of the word control block 27a is fixed at a value greater than, and between times T ₃ ~ time T ₄ to reach the first switching換設value of the speed command calculated value is predetermined feedforward control the feed forward gain to the block 27a is reduced by the ramp-like, also, the smaller the time T ₄ after than the first switching換設value of the speed command calculated value is predetermined smaller feedforward gain to the feed forward control block 27a By setting the position control device 40 using the feedforward setting means 42, the feedforward gain is suppressed from overshooting at the end of positioning and from the start of positioning while suppressing the occurrence of shock accompanying the change of the set value. The cycle time until the end can be shortened.

  FIG. 4 is a waveform diagram for explaining the operation when the feedforward setting means 43 is used in the position control device 40 shown in FIG.

That is, when the position control device 40 starts the positioning control operation, the feedforward setting means 43 obtains a speed command calculation value based on a change in pulse frequency included in the position command value in the pulse train format from the position command block 21. The change is monitored, and as shown in FIG. 4, the speed command calculation value increases, and then the vehicle enters a deceleration state, and after time T _{1 when} it becomes smaller than a predetermined switching set value, the feed forward control block 27 a By setting the feedforward gain smaller, the position control device 40 using the feedforward setting means 43 suppresses overshoot at the end of positioning and feedforward control when the speed command calculation value is in the acceleration state. The feed forward gain to block 27a is fixed at a larger value. By, enabling a further shortening of the cycle time from the start to the end position.

  FIG. 5 is a waveform diagram for explaining the operation when the feedforward setting means 44 is used in the position control device 40 shown in FIG.

That is, when the position control device 40 starts the positioning control operation, the feedforward setting means 44 obtains a speed command calculation value based on a change in pulse frequency included in the position command value in the pulse train format from the position command block 21. The change is monitored and, as shown in FIG. 5, the speed command calculation value increases, and then the vehicle is decelerated, and after time T _{1 when the} speed command calculation value becomes smaller than a predetermined switching set value, the feed forward control block 27a In the position control device 40 using this feedforward setting means 44, the feedforward gain is decreased by a ramp function, and finally the feedforward gain to the feedforward control block 27a is fixed to a smaller value. , The feed forward gain is changed by changing the set value. Positioning is started by suppressing overshoot at the end of positioning and fixing the feedforward gain to the feedforward control block 27a when the speed command calculation value is in an acceleration state with a larger value. This makes it possible to further shorten the cycle time from start to finish.

  In the description of the operation of the present invention based on the waveform diagrams of FIGS. 2 to 5, the feedforward gain setting value, the switching setting value, and the ramp function gradient value in each state are as follows. The value determined in advance by trial run etc. shall be used.

  FIG. 6 is a circuit configuration diagram of a position control apparatus showing a second embodiment of the present invention. In this figure, components having the same functions as those of the conventional position control apparatus 30 shown in FIG. A description thereof will be omitted here.

  In this position control device 50, instead of the conventional position adjuster 32, a differentiator 36 a and a feedforward control block 37 that are changed so that the differentiator 36 can output the output value to the outside are also provided in the feedforward control block 37 a. The position adjuster 32a changed to is provided.

  In the feedforward control block 37a, the position command value from the position command block 31 is differentiated by the differentiator 36a to extract a speed component included in the position command value, and the extracted value (speed command calculation value) is obtained. And a function of outputting a value obtained by multiplying the feedforward gain set and output by any of the feedforward setting means 51 to 54 as a new correction amount.

  FIG. 7 is a waveform diagram for explaining the operation when the feedforward setting means 51 is used in the position control device 50 shown in FIG.

That is, when the position control device 50 starts the positioning control operation, the feedforward setting means 51 includes the position command value in the data format from the position command block 31 output from the differentiator 36a forming the position adjuster 32a. monitoring the change in the speed command calculated value based on the change of the data, as shown in FIG. 7, a feed-forward of the speed command calculated value to the feedforward control block 37a is a small time T ₀ previously than the predetermined switching換設value set smaller gain, also during the speed command calculated value of a predetermined switching換設value greater than the time T ₀ ~ time T ₁ is set larger feedforward gain to the feed forward control block 37a, furthermore, feed smaller time T ₁ after switching換設value of the speed command calculated value predetermined Forwarding By setting the feedforward gain to the control block 37a smaller, the position control device 50 using the feedforward setting means 51 suppresses overshoot at the end of positioning and shortens the cycle time from the start to the end of positioning. And make it possible.

  FIG. 8 is a waveform diagram for explaining the operation when the feedforward setting means 52 is used in the position control device 50 shown in FIG.

That is, when the position control device 50 starts the positioning control operation, the feedforward setting means 52 includes the position command value in the data format from the position command block 31 output from the differentiator 36a forming the position adjuster 32a. As shown in FIG. 8, the change in the speed command calculation value based on the change in the generated data is monitored, and before the time T ₁ when this speed command calculation value is smaller than the predetermined first switching set value, set smaller feedforward gain, also, between times T ₁ ~ time T _2, to reach the second switching換設value of the speed command calculated value is determined in advance a feed-forward gain of the feedforward control block 37a Increased by ramp function, and when the speed command calculation value exceeds the second switching setting value Between time T ₂ and time T ₃ , the feed forward gain to the feed forward control block 37a is fixed at a larger value, and the time T until the speed command calculation value reaches a predetermined first switching set value. ₃ to time between T ₄ decreases the feedforward gain to the feed forward control block 37a by ramp function like, also, the smaller the time T ₄ after than the first switching換設value of the speed command calculated value predetermined feedforward By setting the feedforward gain to the control block 37a smaller, the position control device 50 using this feedforward setting means 52 performs positioning while suppressing the occurrence of shock associated with the change of the set value of the feedforward gain. Suppression of overshoot at the end and cycle from positioning start to end Which enables a reduction of the im.

  FIG. 9 is a waveform diagram for explaining the operation when the feedforward setting means 53 is used in the position control device 50 shown in FIG.

That is, when the position control device 50 starts the positioning control operation, the feedforward setting means 53 includes the position command value in the data format from the position command block 31 output from the differentiator 36a forming the position adjuster 32a. 9 is monitored, and as shown in FIG. 9, the speed command calculation value increases, and thereafter, the speed command calculation value increases, then the vehicle enters a decelerating state, and becomes a time T that is smaller than a predetermined switching set value. _{In 1 and} later, by setting the feedforward gain to the feedforward control block 37a smaller, the position control device 50 using the feedforward setting means 53 suppresses overshooting at the end of positioning and calculates the speed command. Feed value to the feed forward control block 37a when the value is in the acceleration state By fixing the word gain a larger value, thereby enabling a further shortening of the cycle time from the start to the end position.

  FIG. 10 is a waveform diagram for explaining the operation when the feedforward setting means 54 is used in the position control device 50 shown in FIG.

That is, when the position control device 50 starts the positioning control operation, the feedforward setting means 54 includes the position command value in the data format from the position command block 31 output from the differentiator 36a forming the position adjuster 32a. The change of the speed command calculation value based on the change of the data to be monitored is monitored, and as shown in FIG. 10, the speed command calculation value increases, and then the vehicle enters the deceleration state and becomes the time T when it becomes smaller than the predetermined switching setting value. _{After 1} , the feedforward gain to the feedforward control block 37a is decreased by a ramp function, and finally the feedforward gain to the feedforward control block 37a is fixed to a smaller value, thereby setting this feedforward setting. In the position control device 50 using the means 54, the feed forward While suppressing the occurrence of shock due to the change in the set value of the gain, suppressing the overshoot at the end of positioning, and increasing the feedforward gain to the feedforward control block 37a when the speed command calculation value is in the acceleration state By fixing with a value, the cycle time from the start to the end of positioning can be further shortened.

  In addition, in the description of the operation of the present invention based on the waveform diagrams of FIGS. 7 to 10, the feedforward gain setting value, the switching setting value, and the ramp function gradient value in each state are as follows. The value determined in advance by trial run etc. shall be used.

  FIG. 11 is a circuit configuration diagram of a position control apparatus showing a third embodiment of the present invention. In this figure, components having the same functions as those of the position control apparatus 40 shown in FIG. ing.

  In this position control device 60, the feedforward setting means 41 to 44 provided in the position control device 40 shown in FIG. 1 are deleted, and in addition to the function of the position command block 21 described above, the position target value is set outside. One of the position command block 21a, the integrator 61, and the feedforward setting means 62 and 63 changed so as to be output is provided.

  FIG. 12 is a circuit configuration diagram of a position control apparatus showing a fourth embodiment of the present invention. In this figure, components having the same functions as those of the position control apparatus 60 shown in FIG. ing.

  In this position control device 70, the integrator 61 and the feedforward setting means 62 and 63 provided in the position control device 60 shown in FIG. 11 are deleted, and the integrator 71 and the feedforward setting means 72 and 73 are newly added. Either one is provided.

  FIG. 13 shows the operation when the integrator 61 and the feedforward setting means 62 or the integrator 71 and the feedforward setting means 72 are used in the position control device 60 shown in FIG. 11 and the position control device 70 shown in FIG. FIG.

That is, when the position control devices 60 and 70 start the positioning control operation, the feedforward setting means 62 and 72 moves the movement amount based on the position command value in the pulse train format from the position command block 21a output from the integrators 61 and 71. The change in the calculated value is monitored, and as shown in FIG. 13, after the time T _{1 when the} calculated amount of movement increases and exceeds the switching set value set based on the position target value output by the position command block 21a. By setting the feedforward gain to the feedforward control block 27a smaller, the position control devices 60 and 70 using the feedforward setting means 62 and 72 suppress overshoot at the end of positioning and the time. larger feed-forward gain of T ₁ to a previous feedforward control block 27a By setting the length, the cycle time from the start to the end of positioning can be further shortened.

  14 shows the operation when the integrator 61 and the feedforward setting means 63 or the integrator 71 and the feedforward setting means 73 are used in the position control device 60 shown in FIG. 11 and the position control device 70 shown in FIG. FIG.

That is, when the position control devices 60 and 70 start the positioning control operation, the feedforward setting means 63 and 73 shifts based on the position command value in the pulse train format from the position command block 21a output from the integrators 61 and 71. The change of the calculated value is monitored, and as shown in FIG. 14, after the time T _{1 when the} calculated value of the movement amount increases and exceeds the switching set value set based on the position target value output by the position command block 21a. Then, the feedforward gain to the feedforward control block 27a is decreased by a ramp function, and finally, the feedforward gain to the feedforward control block 27a is fixed to a smaller value, so that this feedforward setting means 63 , 73 using position control devices 60, 70, feedforward gain Suppressing the occurrence of shock due to on to change the set value, further, the suppression of the overshoot at the positioning completion, by setting larger the feedforward gain to the time T ₁ prior feedforward control block 27a The cycle time from the start to the end of positioning can be further shortened.

  In the description of the operation of the present invention based on the waveform diagrams of FIGS. 13 and 14, the feedforward gain setting value, the switching setting value, and the ramp function gradient value in each state are as follows. The value determined in advance by trial run etc. shall be used.

  FIG. 15 is a circuit diagram of a position control apparatus showing a fifth embodiment of the present invention. In this figure, components having the same functions as those of the conventional position control apparatus 30 shown in FIG. A description thereof will be omitted here.

  In this position control device 80, in addition to the function of the position command block 31, the position command block 31a changed so that the position target value can be output to the outside, and the conventional position adjuster 32 are used in place of the feed forward. A position adjuster 32b in which the control block 37 is changed to a feedforward control block 37a is provided.

  In this configuration, the feedforward control block 37a via the differentiator 36 extracts the velocity component included in the position command value from the position command block 31, and feedforward setting means 81, 82 has a function of outputting a value obtained by multiplying the feed-forward gain set and output at any of 82 as a new correction amount.

  FIG. 16 is a circuit configuration diagram of a position control apparatus showing a sixth embodiment of the present invention. In this figure, components having the same functions as those of the position control apparatus 80 shown in FIG. ing.

  That is, the position control device 90 includes either feedforward setting means 91 or 92 instead of the feedforward setting means 81 or 82 shown in FIG.

  FIG. 17 is a waveform diagram for explaining the operation when the feedforward setting means 81 or the feedforward setting means 91 is used in the position control device 80 shown in FIG. 15 and the position control device 90 shown in FIG.

That is, when the position control devices 80 and 90 start the positioning control operation, the feedforward setting means 81 and 91 are the movement amount based on the position command value in the data format from the position command block 31a or the movement output from the integrator 38. The amount detection value is used as a movement amount calculation value, and the change is monitored. As shown in FIG. 17, the movement amount calculation value increases, and the switching setting value set based on the position target value output by the position command block 31a. After time T ₁ exceeding the time point, by setting the feed forward gain to the feed forward control block 37a to be smaller, the position control devices 80, 90 using the feed forward setting means 81, 91 can be used at the end of positioning. the suppression of overshooting, fees to the time T ₁ prior feedforward control block 27a The cycle time from the start to the end of positioning can be further shortened by setting a larger forward forward gain.

  FIG. 18 is a waveform diagram for explaining the operation when the feedforward setting means 82 or the feedforward setting means 92 is used in the position control apparatus 80 shown in FIG. 15 and the position control apparatus 90 shown in FIG.

That is, when the position control devices 80 and 90 start the positioning control operation, the feedforward setting means 82 and 92 move the movement amount based on the position command value in the data format from the position command block 31a or the output of the integrator 38. The amount detection value is used as a movement amount calculation value, and the change is monitored. As shown in FIG. 18, the movement amount calculation value increases, and the switching set value set based on the position target value output by the position command block 31a. After the time T ₁ exceeding, the feed forward gain to the feed forward control block 37a is decreased by a ramp function, and finally the feed forward gain to the feed forward control block 37a is fixed to a smaller value. Thus, the position control devices 80, 90 using the feedforward setting means 82, 92 Suppresses the generation of shock due to the change of the set value a feedforward gain, further, greater the suppression of the overshoot at the location end, the feed-forward gain to the time T ₁ prior feedforward control block 37a By setting, the cycle time from the start to the end of positioning can be further shortened.

  In the description of the operation of the present invention based on the waveform diagrams of FIGS. 17 and 18, the feedforward gain setting value, the switching setting value, and the ramp function gradient value in each state are as follows. The value determined in advance by trial run etc. shall be used.

  DESCRIPTION OF SYMBOLS 10 ... Target machine, 11 ... Heavy article, 12 ... Arm, 13 ... Slide moving part, 14 ... Slide rail part, 15 ... Feed screw, 16 ... Coupling, 17 ... Motor, 18 ... Motor encoder, 20, 30, 40 , 50, 60, 70, 80, 90 ... position control device, 21, 21a ... position command block, 22, 22a ... position adjuster, 23 ... subtractor, 24 ... accumulator 25 ... adjuster, 26 ... adder, 27, 27a ... feed-forward control block, 28 ... speed regulator, 29 ... torque regulator, 31,31a ... position command block, 32, 32a, 32b ... position regulator, 33 ... subtractor, 34 ... regulator, 35 ... adder, 36, 36a ... differentiator, 37, 37a ... feedforward control block, 38 ... accumulator, 41-44, 51-54, 62, 63, 72, 81, 82, 1,92 ... feed-forward gain setting means, 61 and 71 ... integrator.

Claims (5)

When performing positioning control based on the position command value commanded to move the controlled machine to the target position and stop it,
A position where a correction amount obtained by multiplying the position command value by a feed forward gain is added to the output value of the position adjustment calculation operation for the positioning control, and the control target machine is driven and controlled based on the added value. In the control device,
A position control apparatus comprising a feedforward gain setting means for changing the set value of the feedforward gain to a new set value in a step function form in the position control apparatus. When performing positioning control based on the position command value commanded to move the controlled machine to the target position and stop it,
A position where a correction amount obtained by multiplying the position command value by a feed forward gain is added to the output value of the position adjustment calculation operation for the positioning control, and the control target machine is driven and controlled based on the added value. In the control device,
A position control apparatus comprising a feedforward gain setting means for changing the set value of the feedforward gain to a new set value in the form of a ramp function in the position control apparatus. In the position control device according to claim 1 or 2,
The position control device according to claim 1, wherein the feedforward gain setting means makes the set value of the feedforward gain smaller when a speed command calculation value based on the position command value is smaller than a predetermined switching set value. In the position control device according to claim 1 or 2,
The feedforward gain setting means reduces the set value of the feedforward gain when a speed command calculation value based on the position command value is smaller than a predetermined switching setting value in a deceleration state. apparatus. In the position control device according to claim 1 or 2,
The feedforward gain setting means reduces the set value of the feedforward gain when the calculated amount of movement based on the position command value exceeds a switching set value that is smaller than the target position by a predetermined value. A characteristic position control device.

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