JP5445173B2 - Active damper control device and control method - Google Patents

Description

  The present invention relates to an active damper control device and control method.

  As is well known, an active damper is used to reduce impact and suppress vibration (vibration suppression) by dynamically controlling an actuator, such as a suspension provided in a vehicle, a die cushion device provided in a press machine, etc. It is applied to various devices. Here, the die cushion device presses the reaction force and the work piece for wrinkle pressing while reducing the impact that occurs when the slide, which is the movable part of the press machine, collides (contacts) with the die cushion pad of the die cushion device. It is a device that generates a pushing force (pressing force against a slide: cushioning force) for molding.

  FIG. 8 is a diagram showing an ideal speed change of the slide and the die cushion pad during press molding. In FIG. 8, the horizontal axis represents time, and the vertical axis represents speed (the descending direction is negative). A curve (solid line) denoted by reference numeral V101 in FIG. 8 is a curve indicating an ideal speed change of the slide, and a curve (broken line) denoted by reference numeral V102 is a curve indicating an ideal speed change of the die cushion pad. is there.

  In the example shown in FIG. 8, the slide that descends at a constant speed (−v) collides with the die cushion pad that is stationary at time t1, and the slide and die cushion pad are processed from time t1 to time t2. They are descending at the same speed with an object in between. Here, the slide speed hardly changes for a while from the time t1 when the slide collides with the die cushion pad, and then the slide and the die cushion pad gradually decelerate, and both speeds become zero at the time t2. Ideally.

  The following Patent Document 1 discloses a slide obtained by detecting the position of a slide by a position sensor in a die cushion mechanism that generates a cushioning force against the slide using a servo motor as a drive source, and second-order differentiation of the position detection value. A technique for correcting a current command value for a servo motor using acceleration is disclosed. By performing such correction, even when the acceleration / deceleration of the slide is abrupt, the cushion force on the slide can follow the command value, and when the acceleration / deceleration of the slide is gentle, vibrations and the like can be suppressed.

JP 2007-905 A

  By the way, in the die cushion device, as described above, it is ideal that the slide speed does not change when the slide collides with the die cushion pad, but actually the slide speed slightly decreases due to the influence of the collision. (Slow down). FIG. 9 is a diagram for explaining an adverse effect caused by slowdown in a conventional die cushion device. In FIG. 9A, the curve (solid line) denoted by reference numeral V201 is a curve indicating the actual speed change of the slide, and the curve denoted by reference numeral V202 (broken line) is the actual speed change of the die cushion pad. It is a curve which shows.

  As shown by a curve V201 in FIG. 9A, it can be seen that at time t1 when the slide collides with the die cushion pad, the speed of the slide is temporarily reduced, and a slowdown occurs. Here, in the die cushion device, control is performed so that the cushioning force on the slide becomes a preset target value from time t1 to time t2 when the slide collides with the die cushion pad. However, if the slide control deviation increases due to the influence of the collision, the control deviation of the die cushion device also increases.

  Then, as shown in FIG. 9B, the error of the cushioning force at time t1 when the slide collides with the die cushion pad becomes large. Further, immediately after the time t1 has elapsed, control is performed to compensate for the error in the cushioning force, so that it can be seen that an overshoot occurs in the cushioning force. When the error of the cushioning force becomes large, a force different from the planned force is applied to the workpiece, so that there is a problem that the quality of the press-molded product is deteriorated or defective.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an active damper control device and control method capable of reducing an error of a cushioning force caused by a slowdown during a collision.

In order to solve the above-described problem, the active damper control device according to the present invention includes a contact member (22) that contacts the contact object (10) and can move in a single axis in conjunction with the movement of the contact object. A control device (40) for an active damper (20) comprising an actuator (23) for driving a member, wherein the contact object is used as a speed command value for use in movement control of the contact object. A correction unit (45 to 47) that corrects a speed command value that reflects a decrease in the speed of the contact object that occurs when contacting, and a command value that drives the actuator using the speed command value corrected by the correction unit And an arithmetic unit (48, 49) for generating
Further, in the active damper control device according to the present invention, the correction unit takes a maximum value when the contact object contacts the contact member as a correction value that reflects a decrease in speed of the contact object, and thereafter A correction value calculation unit (46) for obtaining a correction value whose value decreases exponentially with the passage of time is provided, and the movement control of the contact object is performed using the correction value obtained by the correction value calculation unit. It is characterized by correcting the speed command value used.
In the active damper control device according to the present invention, the correction value calculation unit may calculate the speed of the contact object and the target cushion force of the contact member when the contact object contacts the contact member. Based on this, the maximum value of the correction value is obtained.
In the active damper control device according to the present invention, the calculation unit uses the speed command value corrected by the correction unit to generate a command value for feed-forward control of the actuator. It is characterized by having.
In addition, the active damper control method of the present invention includes a contact member (22) that contacts the contact object (10) and can move in one axis in conjunction with the movement of the contact object, and an actuator ( 23) A control method of an active damper (20) comprising: the contact object generated when the contact object comes into contact with the contact member with a speed command value used for movement control of the contact object. And a second step of generating a command value for driving the actuator using the speed command value corrected in the first step. It is said.

  According to the present invention, the speed command value used for controlling the contact object is corrected to a speed command value that reflects the speed reduction that occurs when the contact object contacts the contact member, and the corrected speed command value is Since the actuator for driving the contact member is used to control, an error in cushioning force caused by slowdown at the time of collision can be reduced.

It is a side view which shows schematic structure of a press machine provided with the die cushion apparatus as an active damper. 3 is a block diagram showing a main configuration of a control device 30 that controls the operation of the slide 10. FIG. 3 is a block diagram showing a configuration of a main part of a control device 40 that controls the operation of the die cushion device 20. FIG. It is a figure which shows the speed correction value _Vsd calculated by the correction _| amendment part calculation part 46. FIG. It is a figure which shows the example of the change of the height position of the slide and die-cushion pad at the time of press molding. It is a figure which shows the speed command value of the slide 10 calculated by the slide speed calculation part 47 of the control apparatus 40. FIG. It is a figure for demonstrating a mode that the bad influence which arises by slowdown is reduced in embodiment of this invention. It is a figure which shows the ideal speed change of the slide and die-cushion pad at the time of press molding. It is a figure for demonstrating the bad influence which arises by slowdown in the conventional die cushion apparatus.

  Hereinafter, an active damper control device and control method according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view showing a schematic configuration of a press machine including a die cushion device as an active damper. As shown in FIG. 1, the press machine 1 includes a slide 10 (contact object) and a die cushion device 20. The slide 10 collides (contacts) with the die cushion device 20 and is sandwiched between them. Panel P (workpiece) is press-molded.

  The slide 10 is configured to be capable of reciprocating in the vertical direction, and an upper mold D1 for press-molding the panel P is attached to the lower part thereof. Specifically, the slide 10 is reciprocated by a crank mechanism including a crankshaft 11 that is rotationally driven by a main motor (not shown), and a connecting rod 12 that connects an eccentric portion of the crankshaft 11 and an upper portion of the slide 10. Is possible.

  The crank mechanism is provided with a rotation angle sensor 13 for detecting the rotation angle of the crankshaft 11, and the speed of the slide 10 is obtained from the rotation angle detected by the rotation angle sensor 13. The detection result of the rotation angle sensor 13 is based on the control device 30 (see FIG. 2, details will be described later) that controls the operation of the slide 10 and the control device 40 (see FIG. 3, details will be described later) that controls the operation of the die cushion device 20. Are output respectively.

  The die cushion device 20 includes a cushion pin 21, a die cushion pad 22, a hydraulic cylinder 23 (actuator), a servo valve 24, a logic valve 25, a check valve 26, a stroke sensor 27, and pressure sensors 28a and 28b. Under the control of the device 40, a reaction force for wrinkle pressing and a cushioning force for press-molding the panel P are generated. The die cushion pad 22 is disposed below the slide 10 and supports the lower mold D <b> 2 via the cushion pin 21.

  The die cushion pad 22 is connected to the lower end of one end of the piston of the hydraulic cylinder 23 and can move vertically downward in conjunction with the movement of the slide 10 when the slide 10 collides. The hydraulic cylinder 23 includes an upper chamber 23a and a lower chamber 23b that are partitioned at the other end of the piston, and a necessary cushioning force is obtained by supplying and discharging oil to and from the upper chamber 23a and the lower chamber 23b. Occur. The servo valve 24 switches the supply destination (the upper chamber 23a or the lower chamber 23b of the hydraulic cylinder 23) and the supply amount of pressurized oil supplied from a pump (not shown) under the control of the control device 40, and The oil discharge source (the upper chamber 23a or the lower chamber 23b of the hydraulic cylinder 23) and the discharge amount are switched. The oil discharged from the hydraulic cylinder 23 is stored in a tank (not shown) that stores oil used in the hydraulic cylinder 23.

  The logic valve 25 is provided in a pipe connecting the upper chamber 23a of the hydraulic cylinder 23 and the servo valve 24, and the flow path of the pipe is turned off or opened under the control of the control device 40. The check valve 26 is provided in a pipe connecting the upper chamber 23a of the hydraulic cylinder 23 and the servo valve 24 and a tank (not shown), and the hydraulic pressure of the upper chamber 23a of the hydraulic cylinder 23 is preset. It is a valve that opens when it becomes smaller than the threshold value.

  The stroke sensor 27 is a sensor that detects the amount of movement of the die cushion pad 22 in the vertical direction. The pressure sensors 28a and 28b are sensors that detect the hydraulic pressure in the upper chamber 23a and the hydraulic pressure in the lower chamber 23b, respectively. The detection results of the stroke sensor 27 and the pressure sensors 28a and 28b are output to the control device 40.

  Next, the control devices 30 and 40 for controlling the operation of the press machine 1 will be described in order. FIG. 2 is a block diagram showing a main configuration of the control device 30 that controls the operation of the slide 10. As shown in FIG. 2, the control device 30 includes a speed target value calculation unit 31, a speed calculation unit 32, a calculation unit 33, and a PI control unit 34, and a rotation angle signal S <b> 1 indicating the detection result of the rotation angle sensor 13. Is used to output a control signal Q1 for controlling the torque of a main motor (not shown) that rotationally drives the crankshaft 11.

  The speed target value calculation unit 31 calculates a target value for the rotational speed of the crankshaft 11 based on a preset setting value. The speed calculation unit 32 calculates the actual rotation speed of the crankshaft 11 using the rotation angle signal S1 output from the rotation angle sensor 13. The calculation unit 33 obtains an error signal indicating a difference between the target value of the rotation speed of the crankshaft 11 calculated by the speed target value calculation unit 31 and the actual rotation speed of the crankshaft 11 calculated by the speed calculation unit 32. . The PI control unit 34 generates a control signal Q1 for PI (proportional integration) control of torque generated by a main motor (not shown) so that the error signal obtained by the calculation unit 33 is zero. As described above, the control device 30 feeds back the rotation angle signal S1 indicating the detection result of the rotation angle sensor 13 and controls the torque of the main motor (not shown).

  FIG. 3 is a block diagram showing a main configuration of the control device 40 that controls the operation of the die cushion device 20. As shown in FIG. 3, the control device 40 includes a cushion force target value calculation unit 41, a cushion force calculation unit 42, a calculation unit 43, a PI control unit 44, a speed calculation unit 45, a correction value calculation unit 46, and a slide speed calculation unit 47. , An F / F control unit 48 (feed forward control unit), and an addition unit 49, and a rotation angle signal S1 indicating the detection result of the rotation angle sensor 13 and a pressure signal S11 indicating the detection result of the pressure sensors 28a and 28b. , S12, a control signal Q2 for controlling the opening degree of the servo valve 24 is output.

  The cushion force target value calculation unit 41 calculates a target value of the cushion force that should be generated by the die cushion device 20 based on a preset setting value. The cushion force calculation unit 42 calculates the actual cushion force generated in the hydraulic cylinder 23 using the pressure signals S11 and S12 output from the pressure sensors 28a and 28b. The calculation unit 43 obtains an error signal indicating a difference between the cushion force target value calculated by the cushion force target value calculation unit 41 and the actual cushion force of the hydraulic cylinder 23 calculated by the cushion force calculation unit 42. The PI control unit 44 generates a control signal for PI control of the opening degree of the servo valve 24 so that the error signal obtained by the calculation unit 43 is zero.

The speed calculation unit 45 calculates the actual rotation speed of the crankshaft 11 using the rotation angle signal S1 output from the rotation angle sensor 13. The correction value calculation unit 46 includes the rotation angle signal S1 from the rotation angle sensor 13, the cushion force target value calculated by the cushion force target value calculation unit 41, and the actual crankshaft 11 calculated by the speed calculation unit 45. Using the rotational speed, a speed correction value that simulates a slowdown when the slide 10 collides with the die cushion pad 22 is calculated. Specifically, the correction value calculation unit 46 obtains the speed correction value V _sd using the following equation (1).

  However, in the above equation (1), the time when the slide 10 collides with the die cushion pad 22 is t1. Here, since the rotation angle of the crankshaft 11 and the height position of the slide 10 correspond to each other, the timing at which the slide 10 collides with the die cushion pad 22 (time t1) is output from the rotation angle sensor 13. Calculated by the rotation angle indicated by the rotation angle signal S1.

Also, P ₁ in the formula (1) is a function for obtaining the speed reduction amount of the slide 10 by slowdown, P ₂ is a parameter indicating the recovery characteristics of the speed that is reduced by slowing down. Here, the function P ₁ depends on the speed v _slide of the slide 10 at the time of the collision and the target value F _{c of the} cushion force, and the parameter P ₂ controls the control system of the slide 10 including the control device 30. Depends on responsiveness. The speed v _{slide of the} slide 10 is obtained by the correction value calculation unit 46 using the rotation angle signal S1 from the rotation angle sensor 13 and the calculation result of the speed calculation unit 45. Further, the cushion force target value F _c is calculated by the cushion force target value calculation unit 41.

FIG. 4 is a diagram illustrating the speed correction value V _sd calculated by the correction unit calculation unit 46. As shown in FIG. 4, the speed correction value V _sd is the value in before the time t1 when the slide 10 collides against the die cushion pad 22 is zero, a maximum value P ₁ at time t1, the elapsed subsequent time As the value decreases exponentially. Incidentally, a time period required until as shown in FIG. 4, the value of the speed correction value V _sd at time t1 becomes the maximum value P _{1 (1} / e) is indicated by the parameter P _2.

  The slide speed calculation unit 47 calculates a speed command value for the slide 10 using the rotation angle signal S1 from the rotation angle sensor 13 and the actual rotation speed of the crankshaft 11 calculated by the speed calculation unit 45 and calculates the speed command value. The speed command value is corrected to a speed command value that reflects the speed reduction due to slowdown. The F / F control unit 48 uses the speed command value calculated by the slide speed calculation unit 47 to generate a control signal for feeding forward the servo valve 24. The adding unit 49 generates a control signal Q2 obtained by adding the control signal generated by the PI control unit 44 and the control signal generated by the F / F control unit 48.

  Thus, the control device 40 controls the opening degree of the servo valve 24 by feeding back the pressure signals S11 and S12 indicating the detection results of the hydraulic pressure in the upper chamber 23a and the lower chamber 23b of the hydraulic cylinder 23. In addition, the control device 40 obtains a speed command value that reflects the decrease in the speed of the slide 10 due to slowdown, and feeds forward a control signal corresponding to the speed command value to control the opening degree of the servo valve 24.

  Next, operation | movement of the press machine in the said structure is demonstrated. FIG. 5 is a diagram illustrating an example of changes in the height positions of the slide and the die cushion pad during press molding. The slide 10 and the die cushion pad 22 are respectively arranged at height positions H1 and H2 that are determined in advance by the control of the control devices 30 and 40 before the molding of the panel P is started. And the panel P is arrange | positioned on the lower metal mold | die D2 supported on the die cushion pad 20 via the cushion pin 21. FIG.

  When the press molding of the panel P is started, calculation of the target value of the rotational speed of the crankshaft 11 is started in the speed target value calculation unit 31 of the control device 30 shown in FIG. Then, the calculation unit 33 obtains an error signal indicating a difference between the target value calculated by the speed target value calculation unit 31 and the actual rotational speed of the crankshaft 11 calculated by the speed calculation unit 32. A control signal Q1 corresponding to the signal is output from the PI control unit 34. The torque of the main motor is controlled by the control signal Q1, and the rotation of the crankshaft 11 is started, whereby the slide 10 disposed at the height position H1 starts to descend.

  In parallel with the above-described operation, the cushion force target value calculation unit 41 of the control device 40 shown in FIG. Then, an error signal indicating a difference between the target value calculated by the cushion force target value calculation unit 41 and the actual cushion force generated in the hydraulic cylinder 23 calculated by the cushion force calculation unit 42 is generated in the calculation unit 43. The PI control unit 44 outputs a control signal corresponding to this error signal.

  When the rotation of the crankshaft 11 is started and the slide 10 starts to descend, the speed calculation unit 45 of the control device 40 calculates the actual rotation speed of the crankshaft 11 and the correction value calculation unit 46 calculates the speed. A correction value is calculated. Then, the slide speed calculator 47 calculates the speed command value of the slide 10. Here, as described with reference to equation (1) and FIG. 4, the speed correction value calculated by the correction value calculation unit 46 is zero before time t1 when the slide 10 collides with the die cushion pad 22. For this reason, the speed command value calculated by the slide speed calculation unit 47 is not corrected. When the speed command value of the slide 10 is calculated, a control signal corresponding to the speed command value is output from the F / F control unit 48.

  The control signal output from the PI control unit 44 and the control signal output from the F / F control unit 48 are added by an adding unit 49 to generate a control signal Q2. The opening degree of the servo valve 24 is controlled by the control signal Q2, and the cushion force of the hydraulic cylinder 23 is controlled to become the cushion force indicated by the target value calculated by the cushion force target value calculation unit 41.

  By repeating the above control, the slide 10 continues to descend. When the slide 10 descends to the height position H2 in FIG. 5, the slide 10 collides with the die cushion pad 22 (time t1). Then, a speed correction value that simulates a slowdown when the slide 10 collides with the die cushion pad 22 is calculated by the correction value calculation unit 46 of the control device 40, and the speed reduction due to the slowdown is reflected in the slide speed calculation unit 47. A speed command value of the slide 10 is calculated (first step).

  FIG. 6 is a diagram illustrating the speed command value of the slide 10 calculated by the slide speed calculation unit 47 of the control device 40. As shown in FIG. 6, the speed of the slide 10 commanded by the speed command value calculated by the slide speed calculator 47 rapidly decreases at time t <b> 1 when it collides with the die cushion pad 22, and then the decreased speed gradually increases. This is a recovery and reflects the decrease in the speed of the slide 10 due to the slowdown shown in FIG.

  After time t1 when the slide 10 collides with the die cushion pad 22, a control signal corresponding to the speed command value of the slide 10 calculated using the speed correction value (see FIG. 6) of the correction value calculation unit 46 is F / F. It is generated by the control unit 48 (second step), and this control signal is fed forward to control the opening degree of the servo valve 24. FIG. 7 is a diagram for explaining how adverse effects caused by slowdown are reduced in the present embodiment. In FIG. 7A, a curve (solid line) denoted by reference numeral V11 is a curve indicating an actual speed change of the slide 10, and a curve denoted by reference numeral V12 (broken line) is an actual curve of the die cushion pad 22. It is a curve which shows a speed change.

  When FIG. 7A is compared with FIG. 9A, there is no significant difference in the speed change of the slide 10 and the speed change of the die cushion pad 22, and the slide 10 collides with the die cushion pad 22 also in this embodiment. It can be seen that there is a decrease in speed. On the other hand, comparing FIG. 7B and FIG. 9B, in this embodiment, as shown in FIG. 7B, the error of the cushioning force immediately after the time t1 has elapsed is small, and FIG. It can be seen that the overshoot is smaller than 9 (b).

  As described above, in the present embodiment, the speed command value used for the control of the slide 10 is corrected to the speed command value that reflects the speed decrease that occurs when the slide 10 collides with the die cushion pad 22. Since the servo valve 24 is feedforward controlled using the speed command value, an error in the cushioning force caused by the slowdown at the time of collision can be reduced. As a result, since it is possible to suppress a force different from the planned force from acting on the panel P, it is possible to prevent the quality deterioration of the press-molded product and the occurrence of defects.

  As mentioned above, although the control apparatus and control method of the die-cushion apparatus by one Embodiment of this invention were demonstrated, this invention is not restrict | limited to the said embodiment, It can change freely within the scope of the present invention. For example, in the above embodiment, the example in which the speed command value of the slide 10 is obtained by the control device 40 and the speed command value is corrected by the control device 40 has been described. However, the speed command value of the slide 10 may be obtained by the control device 10 and the speed command value may be corrected by the control device 40.

  Moreover, although the said embodiment demonstrated the example which uses the hydraulic cylinder in which oil is supplied from the outside as an actuator, this invention is applicable also to the die cushion apparatus provided with hydraulic cylinders other than this hydraulic cylinder. In the above-described embodiment, the die cushion device has been described as an example of the active damper. However, the present invention can be applied to control of an active damper other than the die cushion device.

DESCRIPTION OF SYMBOLS 10 Slide 20 Die cushion apparatus 22 Die cushion pad 23 Hydraulic cylinder 40 Control apparatus 45 Speed calculation part 46 Correction value calculation part 47 Slide speed calculation part 48 F / F control part 49 Adder part

Claims (5)

A control device for an active damper, comprising: a contact member that contacts a contact object and is movable in one axis in conjunction with the movement of the contact object; and an actuator that drives the contact member,
A correction unit that corrects a speed command value used for movement control of the contact object to a speed command value that reflects a decrease in speed of the contact object that occurs when the contact object contacts the contact member;
An active damper control device comprising: a calculation unit that generates a command value for driving the actuator using the speed command value corrected by the correction unit.   The correction unit takes a maximum value when the contact object contacts the contact member as a correction value that reflects a decrease in speed of the contact object, and thereafter the value decreases exponentially with the passage of time. A correction value calculation unit for obtaining a correction value is provided, and a speed command value used for movement control of the contact object is corrected using the correction value obtained by the correction value calculation unit. The control apparatus of the active damper of 1.   The correction value calculation unit obtains a maximum value of the correction value based on a speed of the contact object at a time when the contact object contacts the contact member and a target cushion force of the contact member. The control apparatus for an active damper according to claim 2.   The said calculating part is provided with the feedforward control part which produces | generates the command value which performs feedforward control of the said actuator using the speed command value correct | amended by the said correction | amendment part. The active damper control device according to any one of the preceding claims. A control method for an active damper, comprising: a contact member that contacts a contact object and is movable in one axis in conjunction with the movement of the contact object; and an actuator that drives the contact member,
A first step of correcting a speed command value used for movement control of the contact object to a speed command value reflecting a decrease in speed of the contact object that occurs when the contact object contacts the contact member;
And a second step of generating a command value for driving the actuator using the speed command value corrected in the first step.

Images