JP4544248B2 - Robot control device - Google Patents

Description

【Technical field】
[0001]
A conventional robot controller will be described in Japanese Patent Application Laid-Open No. 11-179691. According to such a gazette, a lock that controls the position of the arm of the robot by the operation of the servo control unit and locks the brake for a predetermined time in the robot control device provided with a brake that brakes the arm when the servo control unit is not operating. It has a time setting unit and a release time setting unit that releases the brake for a predetermined time, and when there is a brake release command from the operation unit, the brake is locked and locked according to the set time of the lock time setting unit and the release time setting unit. The thing provided with the brake control part which performs cancellation | release alternately is described.
[0002]
According to such a robot control device, when the operator gives a command to release the brake, the brake release and the lock operation can be intermittently performed by the set values of the brake release time setting unit and the lock time setting unit. Therefore, it is possible to suppress an excessive movement due to the weight of the robot arm and to finely adjust the arm and smoothly move the arm.
[0003]
However, the conventional robot control device has a plurality of motors, and does not assume tandem control in which one movable part is operated by the motors. For this reason, even when the on / off timing of the brake signal is the same, the amount of movement of the motor varies depending on the variation in the torque generated, the on time, and the off time of each brake. As a result, there is a problem in that the amount by which the movable part is moved is different.
DISCLOSURE OF THE INVENTION
[0004]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a robot control apparatus that can control the brake so that the movement amounts of the respective motors are equal.
[0005]
The robot control device according to the present invention includes a movable unit that moves in the Z-axis direction, and first and second driving units that respectively drive one end and the other end of the movable unit via first and second moving mechanisms. Two motors, first and second position detection means for detecting the rotational positions of the first and second motors and generating first and second position detection signals, respectively, and the first and second The first and second brakes for restraining and releasing the rotation of the two motors, the first and second control units for driving the first and second motors, respectively, and a predetermined cycle based on an input signal. The first and second brake control means for repeatedly releasing and restraining the first and second brakes a plurality of times and the brake release command are received, and the first and second control units are disabled during the brake release duration. both If you, the first, on the basis of the second position detection signal, the first, the second The first such置検out signals match, the second brake, an adjustment signal for changing the Deyutei is the ratio of the duty time and the opening time in the same period, the first, second brake control means And a central processing unit for outputting .
[0006]
According to the present invention, the central processing unit receives the brake release command, invalidates the first and second control units within the duration of the brake release, and based on the first and second position detection signals. , first as the first, the second position detection signal coincides, the second brake, an adjustment signal for changing the Deyutei is the ratio of the duty time and the opening time in the same period, the first, second Output to the brake control means. Thereby, the rotation position of the 1st and 2nd motor which drives the one end part and other end part of a movable part becomes equal. Therefore, the positions of the Z-axis direction components at the one end and the other end of the movable portion are equal. Therefore, the movable part can move smoothly during maintenance.
[0007]
Further, the central processing unit obtains a difference between the first position detection signal and the second position detection signal, and determines that the difference is greater than a predetermined threshold , the adjustment signal is output from the first and second position detection signals . also be output from the brake control means is preferred.
[0008]
According to the present invention, the central processing unit outputs the adjustment signal to the first and second brake control means only when the difference between the first position detection signal and the second position detection signal is larger than the threshold value. For this reason, the brake control is simplified.
[0009]
Further, the central processing unit compares the first position detection signal and the second position detection signal, and drives the end located above in the Z-axis direction among the one end and the other end based on the comparison. the first adjustment signal the first or second brake corresponding to the first or second motor, also be output from the second brake control means is preferred.
[0010]
According to the present invention, the central processing unit is configured to compare the first or second motor corresponding to the first or second motor that drives one of the one end and the other end positioned in the upper direction in the Z-axis direction . Change the brake adjustment signal . That is, the brake restraint time corresponding to the motor positioned above is changed. Thereby, it can prevent that the position of a movable part falls rapidly. For this reason, safety is further ensured.
[0011]
Furthermore, the central processing unit obtains the first movement amount of the one end portion and the second movement amount of the other end portion of the movable portion from the first and second position detection signals, and the first movement amount and the second movement amount. comparing the first or the first adjustment signal of the second brake corresponding to the first or second motor for driving the low end of the moving amount of the one end and the other end on the basis of the comparison, the It is preferable to output to 2 brake control means .
[0012]
According to the present invention, the central processing unit adjusts the first or second brake adjustment signal corresponding to the first or second motor that drives the smaller one of the one end and the other end by the comparison. To change. That is, the brake restraint time corresponding to the motor positioned above is changed. Thereby, it can prevent that the position of a movable part falls rapidly. For this reason, safety is further ensured.
[Brief description of the drawings]
[0013]
FIG. 1 is a perspective view of a liquid crystal transfer robot showing an embodiment of the present invention.
FIG. 2 is an overall block diagram of a liquid crystal transfer robot showing an embodiment of the present invention.
FIG. 3 is a block diagram of the robot control apparatus shown in FIG.
FIG. 4 is a flowchart showing the operation of the robot control apparatus shown in FIG.
FIG. 5 is a time chart showing the operation of the robot control apparatus shown in FIG.
FIG. 6 is a time chart showing the operation of the robot control apparatus shown in FIG.
BEST MODE FOR CARRYING OUT THE INVENTION
[0014]
[Example 1]
An embodiment of a robot control apparatus embodying the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of a liquid crystal glass substrate transfer robot (hereinafter referred to as “liquid crystal transfer robot”) showing an embodiment of the present invention, FIG. 2 is an overall configuration diagram of the liquid crystal transfer robot showing an example, and FIG. It is a block diagram which shows the electric system of the liquid-crystal conveyance robot shown in FIG.
[0015]
1 to 3, the liquid crystal transfer robot 1 includes a first side surface portion 2, a second side surface portion 4, and a top plate 9 fixed to the upper ends of the first side surface portion 2 and the second side surface portion 4. The first side surface portion 2 is directly connected to the first motor 11 and has a first shaft 3 as a standing ball screw. The second side surface portion 4 has a second motor 111 inside. And has a second shaft 5 as an upright ball screw, one end 7a is screwed to the first shaft 3 (first moving mechanism), and the other end 7c is second. It is made of a flat plate material that is screwed into the shaft 5 (second moving mechanism) and moves in the Z-axis direction, that is, the vertical direction shown in FIG. 1 by the rotation of the first shaft 3 and the second shaft 5. A movable portion 7 on which a glass substrate is placed is provided, and the movable portion 7 is configured to be capable of rotating in the direction of arrow A shown in FIG.
[0016]
A first brake 13 and a second brake 113 are coupled to the first motor 11 and the second motor 111, respectively. A first position detector 12 and a second position are coupled to the first brake 13 and the second brake 113, respectively. A detector 112 is coupled, and the first brake 13 and the second brake 113 restrain and release the rotation of the first motor 11 and the second motor 111, respectively, and a first position detector as a first position detecting means. 12. The second position detector 112 as the second position detecting means detects the rotational positions of the first motor 11 and the second motor 111, respectively, and generates the first and second position detection signals P1, P2. Is formed.
[0017]
The liquid crystal transfer robot 1 takes in the first and second position detection signals P1 and P2 and controls the first and second motors 11 and 111 and the first and second brakes 13 and 113, and The first servo control unit 33 and the second servo control unit 133 are turned on / off, and the release operation switch 42 is turned on to turn off the first and second servo control units 33 and 133 to thereby turn the first and second brakes. And a manual operation device 40 for turning on and off 13 and 113.
[0018]
The control device 30 analyzes and processes an operation program for operating the movable unit 7, and also executes a central processing unit 31 that performs on (release) and off (restraint) control of the brakes 13 and 113, and the operation program. The common part which has the memory | storage part 32 which memorize | stores etc., the 1st control part which controls the 1st motor 11, and the 2nd control part which controls the 2nd motor 111 are provided.
[0019]
The first control unit includes a servo control unit 33 as a control unit that controls the first motor 11 and the first brake 13, a servo amplifier unit 35 that drives the first motor 11 according to a drive command from the servo control unit 33, and a first control unit. A first brake control unit 37 serving as a first brake control means for generating a first brake signal that is turned on / off to control on / off of the one brake 13, and the first brake 13 is driven by the first brake signal And a brake drive unit 39.
[0020]
The second control unit includes a servo control unit 133 that controls the second motor 111 and the second brake 113, a servo amplifier unit 135 that drives the second motor 111 according to a drive command from the servo control unit 133, and a second brake 113. A brake control unit 137 as a second brake control unit that generates a second brake signal for on / off control for on / off control, and a brake drive unit 139 for driving the second brake 111 by the second brake signal, It has. Here, the brakes 13 and 113 are turned on (released) when the brake signals are turned on, and the brakes 13 and 113 are turned off (restrained) when the brake signals are turned off.
[0021]
The operation of the robot control apparatus configured as described above will be described with reference to FIGS. FIG. 4 is a flowchart showing the operation of the robot controller, and FIGS. 5 and 6 are time charts showing the brake-related operations.
[0022]
First, the central processing unit 31 determines that the operator manually turns on the release operation switch 42 of the manual operation device 40 during maintenance or the like (step S101). Here, when the release operation switch 42 is turned on at time ts, the central processing unit 31 sends signals from the first servo control unit 33 and the second servo control unit 133 to the first and second servo amplifiers 35 and 135. Is turned off, the first motor 11 and the second motor 111 are de-energized (step S103), and the first brake control unit 37 detects the first position from the first position detector 12 via the first servo control unit 33. The second brake control unit 137 takes in the second position detection signal P2 from the second position detector 112 via the second servo control unit 133 (step S105), and takes the first and second brake control units. 37 and 137 give the first and second brake signals to the brakes 13 and 113, respectively, to control the brakes 13 and 113 on and off. Thereby, the movable part 7 gradually moves downward in the Z-axis direction (step S107). That is, the period of the first and second brake signals is T, and the ON time ta and the OFF time tb are the same. Here, even if the first brake signal and the second brake signal are the same, the brake torque generated by each brake 13, 113, the release time from when the brake signal is turned on until each brake 13, 113 is released, the brake signal 13 , 113 is turned off after being turned off, and the restraint time varies depending on the brakes 13, 113. Therefore, the brakes 13 and 113 have different release times and restraint times, and the movement amounts of the motors 11 and 111 are different. Thereby, the position of the one end part 7a and the other end part 7c of the movable part 7 descend | falling to a Z-axis direction will shift | deviate.
[0023]
The central processing unit 31 obtains the difference between the first position detection signal P1 and the second position detection signal P2 as an absolute value Pe, and compares | Pe |> Pr with a predetermined position deviation Pr. (Step S109). If the central processing unit 31 is P1> P2, an adjustment signal is input to the first and second brake control units 37 and 137 at time t0 , and the second brake control unit 137 turns on / off the second brake signal (time The duty of ta = time tb) is maintained constant, and the first brake control unit 37 increases the ON / OFF duty of the first brake signal (step S113). That is, the on-time tc is lengthened while the period T of the first brake signal is kept constant. This shortens the off time td. Here, the position detection signal values P1 and P2 are set so that the movable portion 7 is positioned at a high position when the magnitude is large. As a result, the speed of the first motor 11 controlled by the first brake 13 is controlled to be slightly higher than the speed of the second motor 111 so that the rotational positions of the motors 11 and 111 coincide. That is, the positions of the one end portion 7a and the other end portion 7c of the movable portion 7 coincide with each other and become horizontal.
[0024]
On the other hand, if P2> P1, the central processing unit 31 inputs an adjustment signal to the first and second brake control units 37 and 137 at time t0 , and the first brake control unit 37 turns on / off the first brake signal. The duty of (time ta = time tb) is kept constant, and the second brake control unit 137 increases the ON / OFF duty of the second brake signal (step S115).
[0025]
That is, the on-time tc is made longer than the on-time ta before the time t0 while keeping the period T of the second brake signal constant. As a result, the off time td becomes shorter than the on time tb before the time t0 . As a result, the speed of the second motor 111 controlled by the second brake 113 is slightly increased from the speed of the first motor 13, and the rotational positions of the motors 11 and 113 are controlled to coincide with each other. . For this reason, the one end part 7a and the other end part 7c of the movable part 7 descend | fall in a Z-axis direction in a parallel state, without inclining.
[0026]
In this way, steps S103 to S115 are executed until the release operation switch 42 of the manual operation device 40 is turned off. Eventually, when the release operation switch 42 of the manual operation device 40 is turned off, the on / off control of the brakes 13 and 113 is finished.
[0027]
In step S109 of the above embodiment, the positions of the one end portion 7a and the other end portion 7c of the movable portion 7 are determined using the position detection signals P1 and P2. A first movement amount P1L based on the position detection signal P1 and a second movement amount P2L obtained by integrating the second position detection signal P2 are obtained, and the absolute value PeL of the difference between the first movement amount P1L and the second movement amount P2L is set to be below. It may be obtained as described above and compared with PrL determined in advance.
[0028]
| P1L-P2L | = PeL> PrL
[0029]
In step S111, P1L> P2L is compared. If “Y”, step S113 may be executed, and if “N”, step S115 may be executed.
[0030]
[Industrial applicability]
As described above, the robot control apparatus according to the present invention is applied to robot control.

Claims (4)

A movable part that moves in the Z-axis direction;
A first motor and a second motor for driving one end and the other end of the movable part via first and second moving mechanisms, respectively;
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 rotation of the first and second motors, respectively, and first and second control units for driving the first and second motors, respectively.
First and second brake control means for repeatedly releasing and restraining the first and second brakes at a predetermined cycle based on an input signal a plurality of times;
In response to the brake release command, within the duration of brake release the first, both Disabling second control unit, the first, on the basis of the second position detection signal, the first, the second the first such position detection signal coincides, the second brake, an adjustment signal for changing the Deyutei is the ratio of the duty time and the opening time in the same period, the first, second brake control means A central processing unit to output ,
A robot control device comprising: The central processing unit obtains a difference between the first position detection signal and the second position detection signal, and determines that the difference is larger than a predetermined threshold , the adjustment signal is the first, control apparatus for a robot according to claim 1, characterized in that the output to the second brake control means. The central processing unit compares the first position detection signal and the second position detection signal, and based on the comparison, an end located above the one end and the other end in the Z-axis direction. wherein said adjustment signal the first of said first or second brake corresponding to the first or second motor for driving the parts, to claim 1, characterized in that the output to the second brake control means The robot control device described. The central processing unit obtains the first movement amount of the one end portion and the second movement amount of the other end portion of the movable portion from the first and second position detection signals, and the first movement amount and the second movement amount. comparing the amount, said first and second brake corresponding to the first or second motor to drive the small end of the movement amount of the second end portion and the end portion on the basis of the comparison said adjustment signal the first control apparatus for a robot according to claim 1, characterized in that the output to the second brake control means.

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