WO2005035205A1

WO2005035205A1 - Robot controlling device

Info

Publication number: WO2005035205A1
Application number: PCT/JP2003/013006
Authority: WO
Inventors: Hiroki Takahashi; Atsushi Kitamura; Tomoharu Mizutani
Original assignee: Mitsubishi Denki Kabushiki Kaisha
Priority date: 2003-10-10
Filing date: 2003-10-10
Publication date: 2005-04-21
Also published as: CN1839019A; TW200513361A; TWI277496B; JPWO2005035205A1; CN100488734C; DE10394302T5

Abstract

It comprises a rotatable arm (15), a motor (11) for driving the arm (15), a position detector (12) for detecting the angular position of the motor (11) to generate a position detection signal, a stop (23) for controlling the rotation of the arm (15), a brake (13) for restraining and releasing the rotation of the motor (11), a servo control section (33) for driving the motor (11), and a cancellation operating switch (42) for disabling the servo control section (33) and releasing the brake (13), and a brake control section (37) for changing the time for restraining or releasing the brake (13) according to the angle between the stop (23) and the arm (15) by the actuation of the cancellation operating switch (42).

Description

Specification

Lopot control device

The present invention relates to an improvement of a technique for preventing an arm of a mouth pot from contacting a stopper or the like during maintenance or the like.

Background art

A conventional robot control device will be described with reference to Japanese Patent Application Laid-Open No. H11-179691. According to this publication, in a robot control device provided with a brake that brakes an arm when the servo control unit is not operating, while controlling the position of the arm of the mouth pot by the operation of the servo control unit, A lock time setting section for locking and a release time setting section for releasing the brake for a predetermined time are provided, and when a brake release command is issued from the operation section, according to the set times of the lock time setting section and the release time setting section. It describes a brake control unit that alternately locks and releases the brake.

According to the control device of the lopot, when the operator commands the release of the brake, the release and the lock operation of the brake are intermittently performed by the set values of the brake release time setting section and the lock time setting section. As a result, excessive movement of the mouth pot arm due to its own weight can be suppressed, and fine adjustment and smooth movement of the arm can be performed.

However, with the mouth pot control device configured as described above, the moving speed when the brake is released changes rapidly due to the weight, posture, and load conditions of the arm. There was a problem that the operator had to adjust the time setting while monitoring the movement of the arm. In addition, there was a problem that the service control unit was stopped, and the working points of the arms and the like could come into contact with the stopper, the robot body, peripheral devices, and the like.

Disclosure of the invention

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a control device for a mouth port, which makes it difficult for a work point such as an arm to contact a stopper or a main body during maintenance. It is the purpose.

A mouth pot control device according to a first aspect of the present invention includes: a movable moving member; a motor for driving the moving member; a position detecting means for detecting a position of the motor to generate a position detection signal; A stopper member for restricting the movement of the member, a brake for restraining and releasing the rotation of the motor, a control unit for driving the motor, and a command unit for disabling the control unit and releasing the brake And first brake control means for changing the time of restraining or releasing the brake according to the distance between the stopper member and the moving member by the operation of the command means. It is. A mouth pot control device according to a second aspect of the present invention includes: a rotatable arm; a motor that drives the arm; a position detection unit that detects a rotational position of the motor to generate a position detection signal; A stopper member for regulating the rotation of the arm, a brake for restraining and releasing the rotation of the motor, a control unit for driving the motor, and a command unit for disabling the control unit and releasing the brake And first brake control means for changing the time for restraining or releasing the brake in accordance with the angle between the stopper member and the arm by the operation of the command means. It is.

A mouth pot control device according to a third aspect of the present invention is connected to a working point, and provided with a first rotatable arm provided at a first joint, and a first arm via a second joint. A second arm connected and fixed to the arm, the first and second arms; A first and a second module for driving the arm, a main body connected to the first and the second arm and contacting the working point; First and second position detecting means for detecting the rotational position of the second motor and generating first and second position detection signals, respectively, and detecting the rotation of the first and second motors, respectively. First and second brakes for restraining and releasing, a control unit for driving the first and _second motors, position recognition means for teaching and recognizing a main body position of the main body unit, and the control unit Command means for releasing the first and second brakes together with disabling; and disabling the control unit by the operation of the command means, and performing the work based on the first and second position detection signals. The distance between a point and the position of the main body is obtained, and the first and second brakes are restrained or released according to the distance. A second brake control means for changing between, is characterized in that example Bei a.

The control device for a robot according to a fourth invention is a control device for a three-dimensional space using X, Υ, and Z values within a movable range of the second arm, instead of the position recognition means of the third invention. In place of the setting means for setting and the second brake control means in the third invention, the control section is invalidated by the operation of the command means, and the work is performed based on the first and second position detection signals. Third brake control means for determining a distance between a point and the ≡-dimensional space, and changing the time of restraining or releasing the first and second brakes according to the distance. It is a thing.

A control device for a robot according to a fifth aspect of the present invention comprises: an operating speed calculating means for detecting an operating speed of an arm based on a rotational speed of a motor based on a position detection signal; And a restraining means for restraining the brake when the operating speed exceeds the maximum operating speed.

The control device for a robot according to the sixth aspect of the present invention, A release means for releasing the brake soon after is provided.

According to the first invention, the worker operates the command means, for example, at the time of maintenance, thereby changing the engagement or release time of the brake according to the distance between the working point and one of the stoppers. There is an effect that the point can be prevented from colliding with the stopper member.

According to the second aspect of the present invention, the operator operates the command means during, for example, maintenance, thereby changing the engagement or release time of the brake according to the angle between the arm and the stopper member. There is an effect that collision with members can be prevented beforehand. .

According to the third aspect of the present invention, the operator operates the command means during maintenance, for example, to change the brake restraining or releasing time according to the distance between the working point and the main body. This has the effect that it is possible to prevent beforehand from colliding with the main body.

According to the fourth invention, the operator operates the command means, for example, at the time of maintenance, so that the brake is applied in accordance with the distance between the work point and, for example, the set three-dimensional space set near the peripheral device. Since the restraining or releasing time of the working point is changed, there is an effect that the working point can be prevented from entering the three-dimensional space.

According to the fifth aspect of the present invention, the brake is restrained by the restraining means by comparing the predetermined maximum operating speed with the predetermined operating speed, so that it becomes more difficult for the arm to contact the main body and the like. effective.

According to the sixth invention, there is an effect that the arm can be moved according to the situation after the arm is stopped.

Brief Description of Drawings

FIG. 1 is an overall configuration diagram of a robot system showing one embodiment. FIG. 2 is a block diagram of an electric system of the robot system shown in FIG. FIG. 3 is a model diagram of the robot joint shown in FIG.

FIG. 4 is a table showing the relationship between the angle difference between the arm of the robot and the stopper of FIG. 1 and the pulling torque of the arm.

FIG. 5 is a flowchart showing the operation of the robot shown in FIG.

FIG. 6 is a time chart showing the operation of the brake of FIG.

FIG. 7 is a flowchart showing the operation of the robot according to another embodiment. FIG. 8 is a time chart showing the operation of the brake according to another embodiment. FIG. 9 is a block diagram of an electric system of a robot according to another embodiment. FIG. 10 is an X, Y curve diagram showing a tip position of a second arm of a robot according to another embodiment.

FIG. 11 is a flowchart showing the operation of a robot according to another embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

Example 1

One embodiment of the present invention will be described with reference to FIGS. Fig. 1 is an overall configuration diagram of a robot system showing an example, Fig. 2 is a block diagram showing the electrical system of the robot system shown in Fig. 1, Fig. 3 is a model diagram of a joint consisting of an arm and a motor, and Fig. 4 is a diagram of the arm. FIG. 6 is a correspondence diagram between a load torque and an angle. In FIG. 1, the mouth pot system 1 includes a servo control unit 33 for controlling the mouth pot 3 and a control device 30 having a teaching function as position recognition means for teaching the tip T s (work point) of the mouth pot 3. And a manual operation device 40 having a release operation switch 43 as a command means for executing the operation of the robot 3 and for turning the support control unit 33 on and off.

The mouth pot 3 includes an erect main body 5, a first arm 15 and a second articulation section 20 via a first joint section 10, when connected to the main body 5. Via The second arm 17 to which the tool 19 having the tip Ts is connected and fixed, and the rotational movement of the first arm 15 are restricted, and a stopper as a stopper member provided on the joint 10 is provided. 2 and 3 are provided. The arms 15 and 17 form moving members, and the arm 17 has a tip As.

In FIG. 2, a first motor 11 that drives an arm 15 and a first motor 11 that detects a rotational position of the motor 11 and generates a first position detection signal 0 sl are provided in the joint 10. A position detector 12 is provided as position detection means, and a first brake 13 is provided on the shaft of the motor 11 to prevent movement of the arm 15 when power is cut off. The controller 30 includes a central processing unit 3 1 that analyzes and processes an operation program for operating the mouth pot 3 and executes attitude control of the first arm 15 and the like, on / off control of the brake 13, and the like. , A storage unit 32 for storing an angle difference between the arm 15 and the stopper 23, a servo control unit 33 as a control unit for controlling the motor 11, and a servo control unit 3 3 for the motor 11 A servo amplifier section 35 driven by a drive command from the motor, a brake control section 37 as first brake control means for controlling the motor 11, and a brake drive section 39 for driving the brake 13 are provided. I have.

FIG. 2 does not show the electrical diagram of the second joint. Assuming that the joint 10 is a model shown in Fig. 3 in which the shaft of the motor 11 drives the arm 15 via gears, the brake torque Tb generated by the brake 13 and the motor 11 When the angular velocity is ω, the following equation of motion is established.

TL-Τ b = (J m + J a / n ² ) (d ω / dt) · · · · · (1) where, J m is the moment of inertia of the motor

J a: Arm moment of inertia, n: Reduction ratio, TL: Load torque In the above equation (1), the brake torque T b is zero, that is, the brake 13 is released. During the operation, the arm 15 is rotated by being pulled by the load torque TL of the arm 15. Rearranging the above equation (1) gives the following equation.

J 0 d ω = (Τ L- T b) d t

here, 】. : J m + J a / n ²

o = {(TL—T b) J. } t + A · · · · (3) Since ω = 0 at t = 0, the integration constant Α = 0.

Here, the on / off control of the brake 13 means that the average of the brake torque Tb changes as in the following equation.

T e- T bTonZ (ton + toff)}

Here, t on: brake on time, t off: brake off time On the other hand, assuming that the angle between the arm 15 and the stopper 23 is 0, the distance between the rotation angle center and the stopper 23 is rs, in the circumferential direction. If the moving distance L s of

Θ = L sr s

From the above equation (4), in order to restrain the motor 11 by the brake 13 and stop the arm 15, a brake torque Tb larger than the load torque TL must be generated.

Moreover, if the stop time of the arm 15 by the brake 13 is fixed, the brake torque Tb may be generated in proportion to the angle difference between the arm 15 and the stopper 23. That is, the duty of turning on / off the brake 13 may be proportional to the angle difference between the arm 15 and the stopper 23.

As described above, in order to restrain the motor 11 by the brake 13, a torque Tb larger than the load torque TL must be generated, so the load torque for each angle difference between the arm 15 and the stopper 23 must be measured in advance. Measure TL Then, the table shown in FIG. 4 is stored in the storage unit 32 according to the angle difference. The operation of the robot control device configured as described above will be described with reference to FIGS. FIG. 5 is a flowchart showing the operation of the robot controller, and FIG. 6 is a time chart showing the brake-related operation.

In advance, the worker measures the load torque TL for each angle difference and stores the table shown in FIG. 4 in the storage unit 32 according to the angle difference. Further, the worker contacts the arm 15 as a working point with the stopper 23 and stores the reference position 0r in the storage unit 32.

The central processing unit 31 determines whether or not the off command of the servo control unit 33 has been issued (step s 10 Do). The off command is released by the operator from the manual operation device 40 during maintenance or the like. The central processing unit 31 determines whether or not the switch 42 has been turned on. When the off command is generated, the central processing unit 31 turns off the servo control unit 33 (step S103), and the brake control unit 37 determines whether or not the The position detection signal 0 sl is fetched from the position detector 12 via the control unit 33 (step S 105), and the angle difference 0 e between the arm 15 and the stopper 23 is calculated (step S 1). 0 7), the ON / OFF time of the brake 13 is determined according to the angle difference 0 e as the distance, and the brake signal is input to the brake drive unit 39. The brake drive unit 39 has the time! To release (release) brake 13 for a predetermined time, lock (restrain) for a predetermined time, and move arm 15 Controlling the degree (Sutetsu flop S 1 0 9).

The central processing unit 31 determines whether or not the angle difference has reached a predetermined value, and if not, executes the above steps S105, S107, S109 to execute the angle When the difference reaches a predetermined value (step S122), the brake 13 is restrained and the process ends.

As described above, during manual operation, the on / off control time of the brake 13 was changed according to the angle difference between the arm 15 and the stopper 23. The arm 15 can be prevented from colliding with the stopper 23 beforehand.

In the above-described embodiment, an example in which the motor 11 is of a rotary type has been described, but a linear motor may be used. In the case of a linear motor, the position detector 12 detects the linear position of the linear motor mover, the central processing unit 31 calculates the distance between the linear position and the stopper 23, and according to the calculated distance. The brake 13 may be driven by a brake signal from the brake controller 37. Example 2.

In the above embodiment, the ON / OFF duty of the brake 13 is changed based on the angle difference between the arm 15 and the stopper 17, but the speed of the arm 15 is also taken into consideration. An example in which the on / off duty of the brake 13 is changed will be described below.

When the above equation (3) is reprinted, it becomes as follows.

ω = ά θ / ά t = [(T L — T b) ZJ. ] t

The following equation is obtained by integrating both sides of this equation.

Θ = (TL-Tb) t ² / (2 J o) + B · · · · (7) Since t = 0 and 0 = 0, the integration constant B = = 0.

Θ-(TL-Tb) t ² (2 J.) · · · · (8) In the above equation (8), assuming that the load torque TL is constant irrespective of the angle difference, the arm 15 rotates at the maximum speed. When the speed exceeds the comax, the deceleration of the arm 15 becomes constant by restraining the brake 13. Since the deceleration is constant, the deceleration time is proportional to the angle difference. It is preferable to set the maximum rotation speed c max of the arm 15 in proportion to the angle difference.

The operation of the control device for a port configured as described above will be described with reference to FIGS. FIG. 7 is a flowchart showing the operation of the mouth pot control device, and FIG. 8 is a time chart showing the brake-related operation. In Figure 7, The same reference numerals as those in FIG. 5 indicate the same or corresponding parts, and the description will be omitted.

Steps S101 to S109 are executed as in the first embodiment, and the central processing unit 31 functions as an operation speed calculating means, and obtains the angular speed os of the arm 15 from the position detection signal Θsi, and Comparing with the set angular velocity o max (Step SI 11), if the angular velocity ω s is larger than the maximum angular velocity co max, the servo control unit 33 as the restraint means outputs the brake signal at time tc at time tc. Turn off (hook) to turn off the brake 13, restrain the motor 11, and stop the arm 15 (step S 113).

On the other hand, if the angular velocity ωs is smaller than the angular velocity comax in step S111, step S121 is executed as shown in the first embodiment.

Further, in step S113, the servo control unit 33 as an opening means restrains the motor 11 to stop the arm 15, and then releases the brake 13 so that the arm 15 can operate freely. May be.

As described above, at the time of manual operation, the ON / OFF control time of the brake 13 is changed according to the angle difference between the arm 15 and the stopper 17 and the moving speed of the arm 15 is changed according to the angle difference. Because of the restriction, the arm 15 can be prevented from colliding with the stopper 17 even more. Example 3.

In the first embodiment, the stopper 23 for regulating the rotation of the arm 15 is provided. In the present embodiment, however, the rod 3 that the tip As of the main body 5 and the second arm 17 as the working point can contact is provided. The control of the brake 13 for avoiding the contact between the tip As of the arm 17 and the main body 5 will be described.

The mouth pot system of the present embodiment is the same as that shown in FIG. 1, and includes the electric system shown in FIG. 9 including the second joint portion 20. 9, the same reference numerals as those in FIG. 2 denote the same parts, and a description thereof will be omitted. In FIGS. 1 and 9, the mouth pot 3 has two joints 10 and 20, and the first joint 10 is connected to the first mode. The second joint 20 is driven by the motor 11, the second motor 11 1 that drives the arm 17, and the rotational position of the motor 11 1 is detected to generate a position detection signal 0 s 2 A second position detector 112 serving as a second position detecting means, and a second brake provided on a shaft of the motor 111 and for preventing movement of the arm 17 when power is cut off. 1 1 and 3 are provided.

Controls the motor control section 1 3 3 that controls the motor 1 1 1 1 and the motor amplifier 1 2 4 that drives the motor 1 1 1 by the drive command from the support control section 1 3 3 and the motor 1 1 1 And a brake drive unit 135 for driving the brake 111. The second and third brake control means are constituted by the brake control sections 37 and 1337.

Here, as shown in FIG. 6, assuming that the position of the tip T s of the tool 19 and the tip A s of the arm 17 are equal, the position P (x, y) of the tip A s is defined as the first and second arms 1 If the length of the first arm 15 and the X-axis is 01, and the angle of the second arm 17 and the first arm 15 is Θ2, —The tips P x, P y, and P z of the unit 17 are as follows.

P x = L1cos ^ 1 + L2cos (01 + θ2) ... (9)

P y = L 1 sin ^ 1+ L 2 sin (91+ Θ 2)

P z = (P x 2+ _py 2) i / 2.... (N)

Therefore, the positions P X, P y, and P z of the tip of the arm 17 can be obtained by detecting the position detection signals 0 si and 0 s 2 of the position detectors 12 and 112 from the above formula.

The operation of the robot control device configured as described above will be described with reference to FIGS. 1, 4, 9, and 11. FIG. FIG. 11 is a flowchart showing the operation of the mouth pot control device.

In advance, the worker measures the load torque TL for each angle difference and calculates The table shown in FIG. 4 is stored in the storage unit 32 accordingly. Further, the operator contacts the tip As of the arm 17 with the main body 5 by the control device 30 to teach the main body 5, sets the teaching position, and stores the teaching position in the storage unit 32.

The central processing unit 31 determines whether or not the manual control device 40 issues an off command for the support control units 23, 13 3 as in step S101 of the first embodiment (step S101). S201). When an off command is issued, the central processing unit 31 turns off the support control unit 23, 13 (step S203), and outputs the position detection signal 6 from the position detector 12, 11, 12. > sl, 0s2 (Step S205), obtain the tip positions Px, Py, Pz of the arm 17 and calculate the distance Le between the tip of the arm 17 and the body 5 ( In step S207), the on / off times of the brakes 13 and 113 are determined according to the distance Le to control the brakes 13 and 113 (step S209).

The central processing unit 31 determines whether or not the distance Le reaches a predetermined value (step S211). If not, steps S205, S207, S When 209 is executed and the angle difference 0L reaches a predetermined value, the brakes 13 and 11 are restrained and the process ends.

As described above, at the time of manual operation, the on / off control time of the brakes 13 and 13 was changed according to the distance between the arm 17 and the main body 5, so that the arm 17 collided with the main body 5. Can be prevented beforehand. In the above embodiment, the tip As of the arm 17 was brought into contact with the main body 5 by the controller 30. However, a three-dimensional space was set by the X, Υ, and Z values within the range in which the arm 17 could move. Setting means for determining the distance between the arm 17 and the virtual plane based on the position detection signals Θ si, Θ s2 instead of the step S 107 (second distance calculating means) Alternatively, the brakes 13, 11 may be controlled by determining the on / off time of the brakes 13, 11, 13 according to the distance Le. Further, in the above embodiment, the working point is the tip of the arm 17, but may be an appropriate position of the arm 17. In addition, the working point is connected to the second arm 17 and the tip of the third arm having the third joint may be used.

As described above, the mouth pot control device according to the present invention is suitable for use in manually moving the robot arm.

Claims

1. A movable moving member;

A motor driving the moving member;

Position detecting means for detecting a position of the motor to generate a position detection signal, a stopper member for regulating movement of the moving member,

A brake for restraining and releasing the rotation of the motor;

A control unit for driving the motor;

Commanding means for disabling the control unit and releasing the brake; and changing the time for restraining or releasing the brake according to the distance between the stopper member and the moving member by the operation of the commanding means. A first brake control means;

A control device for a robot, comprising:

2. A rotatable arm,

A motor for driving the arm;

Position detecting means for detecting a rotational position of the motor and generating a position detection signal;

A stopper member for restricting rotation of the arm,

A brake for restraining and releasing the rotation of the motor,

A control unit for driving the motor,

Command means for disabling the control unit, releasing the brake, and changing the time for restraining or releasing the brake in accordance with the angle between the stopper member and the arm by the operation of the command means. Brake control means,

A control device for a robot, comprising:

3. Connectable to the working point and rotatable on the first joint First arm and

A second arm connected and fixed to the first arm via a second joint, first and second motors respectively driving the first and second arms, the first and second motors; A main body that is connected to the arm of

First and second position detecting means for detecting the rotational positions of the first and second motors and generating first and second position detection signals, respectively;

First and second brakes for restraining and releasing the rotation of the first and second motors, respectively;

A control unit that drives the first and second motors;

Position recognition means for teaching and recognizing the main body position of the main body,

Command means for disabling the control unit and releasing the first and second brakes;

The control unit is disabled by the operation of the command means, and a distance between the working point and the main body position is obtained based on the first and second position detection signals. Second brake control means for changing the time of restraining or releasing the second brake;

A control device for a mouth pot, comprising:

4. Instead of the location recognition means in claim 3,

Setting means for setting a three-dimensional space by X, Υ, and Z values within a range in which the second arm can move;

In place of the second brake control means in claim 3, the control section is invalidated by the operation of the command means, and the working point and the three-dimensional position are determined based on the first and second position detection signals. Third brake control means for determining a distance to a space and changing the time of restraining or releasing the first and second brakes according to the distance; 4. The control device for a robot according to claim 3, comprising:

5. Operating speed calculating means for detecting the operating speed of the arm based on the rotational speed of the motor based on the position detection signal;

And a restraining means for restraining the brake when the operating speed exceeds the maximum operating speed by comparing a predetermined maximum operating speed with the operating speed. Or the control device for a robot according to 3.

6. Release means for releasing the brake after a predetermined time after the execution of the restraint means,

7. The mouth pot control device according to claim 5, wherein the mouth pot control device is provided.