JP3508522B2 - Robot control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot controller for releasing a brake of a robot arm while a servo control system is in a non-operation state. 2. Description of the Related Art A conventional apparatus of this type is disclosed in
Japanese Unexamined Patent Application Publication No. 92288 discloses a configuration as follows. When the servo control system is operating, the robot arm control axis is within the range of the control software by the motor which is the drive device, its drive amplifier, the rotation axis of the motor or each axis position detector provided on the robot arm. The position is controlled. In addition, a brake is usually provided on the rotation axis of the motor, and the brake is released when the servo control system is operating, and each axis of the robot is stopped by the brake when the servo control system is not operating It is configured to In general, brakes are configured to mechanically lock each axis in the absence of a brake drive signal in order to prevent the robot arm from falling under its own weight due to a power failure such as a power failure. In order to prevent the load from being applied, a brake release driving force is generated using electromagnetic force, air pressure, or the like to release the brake. When performing an operation of aligning the mechanical origin of the control axis of the robot arm with the control origin, or moving the robot arm to a posture for transportation, it is necessary to move the robot from within the range of the control software to outside the range. Also,
When the robot arm moves out of the range of the control software due to a sudden power failure or the like as disclosed in JP-A-3-92288, the servo control system is deactivated and the brake is released to manually control the robot arm. Needs to be moved within the range. The operation in the former case is performed in the following procedure. First, the robot is moved to the position closest to the mechanical origin or the posture during transportation while the servo control system is operated. Next, the servo control system of the robot is deactivated, and the worker who moves the robot arm enters the movable range of the robot and confirms that the robot arm is ready to support the robot arm. Releases the brake of the robot through the operation unit of the control device. Then, the worker supporting the robot arm moves the robot arm to the mechanical origin or the posture during transportation by hand, and the worker of the operation unit locks the brake through the operation unit of the control device. [0004] In the work of these procedures, before the worker supporting the robot supports the robot, the operator of the operation unit releases the brake or moves the robot arm of a different control axis. When the operator releases the brake when the operator is supporting the robot arm, the robot arm falls at once by gravity. For example, if there is an axis that moves in the vertical direction, ignoring mechanical friction and air resistance, the robot will fall 1 m from the stop state in about 0.45 seconds, causing the robot arm to damage peripheral devices. And may harm workers who support the robot arm. Therefore, as shown in FIG. 4, the release / lock operation of the brake is performed by turning on the release operation switch of the operator.
・ It is performed by the OFF switching operation. However, it is difficult to keep the time interval between release and lock constant by manual operation, causing excessive movement of the robot arm or making fine adjustments and smooth movement for moving the robot arm to the machine origin. There was a problem. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and suppresses excessive movement of a robot arm when a servo control system is not operated, and performs fine adjustment and smooth movement of the robot arm. A possible robot control device is obtained. A robot control apparatus according to the present invention includes a brake control unit provided with a release time setting unit and a lock time setting unit, and a brake release time setting unit and a brake lock time setting unit. The brake release and lock are alternately controlled based on the set time. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment FIG. 1 is a block diagram of a control device for a robot according to Embodiment 1 of the present invention. In the figure, reference numeral 1 denotes an operation unit, which is a part where an operator gives a command necessary for robot control. Reference numeral 2 denotes a central processing unit that generates position control and various functions of the robot based on a control program. Reference numeral 3 denotes a servo control unit, 4 denotes a servo amplifier unit, and 5 denotes a motor, which constitutes a servo control system. At the time of operation of the servo control system, a command relating to movement or stop is given to the servo control unit 3, the command is passed to the servo amplifier unit 4, and finally, the motor 5 is rotated to drive a robot arm (not shown). When a force is generated and there is no movement command, the robot arm balances with its own weight and stops. Also, if there is a movement command,
The robot arm is configured to move by generating a rotational force that offsets the weight of the robot arm. Further, six position detectors are attached to the motor 5. The position detector 6 recognizes the servo control position of the robot arm, and actually detects the rotation angle of the motor 5 and feeds back its output signal to the servo control unit 3 and the servo amplifier unit 4. The robot arm is configured to always maintain the position command value from the operation unit 1. Reference numeral 7 denotes a brake which is mounted between the shaft of the motor 5 and the robot arm. 8 is a brake control unit.
9 is a brake release time setting unit, and 10 is a brake lock time setting unit. The brake release time setting unit 9 and the brake lock time setting unit 10 are assigned to the memory of the central processing unit 2 as parameters of the robot control device,
It is configured such that a change can be made from the operation unit 1 by an operator. Reference numeral 11 denotes a brake driving unit that drives the brake 7 to be actually released or locked by an output signal from the brake control unit 8. The release command of the brake 7 is configured to be generated by pressing a release operation switch (not shown) on the operation unit 1. FIG. 2 is a flowchart for controlling the brake 7 of the robot controller according to the first embodiment. FIG. 3 is a control state diagram showing control of the brake according to the first embodiment. Hereinafter, the figures will be described.
First, in S1, the central processing unit 2 determines the operation state of the release operation switch of the operation unit 1. When the release operation switch of the brake release command is pressed (ON), the process proceeds to S2, and the central processing unit 2 performs a non-operation process of the servo control system. That is, the locking operation of the brake 7 is performed, the signal output to the servo control unit 3, the servo amplifier 4, and the motor 5 is stopped, and the robot arm is stopped by the brake 7.
Next, in S3, the brake control unit 8 reads the release time data from the brake release time setting unit 9 and
Is output to the brake drive unit 11 so as to release only the time corresponding to the release time data. Next, in S4, the brake control unit 8 reads the lock time data from the brake lock time setting unit 9, and locks the brake 7 only for a time corresponding to the lock time data.
A signal is output to 1 and the process returns to S1 for determining the operating state of the release operation switch. Then, as shown in FIG. 3, while the operator keeps pressing the brake release switch of the operation unit 1, the release and the lock operation of the brake 7 are performed based on the respective time data. If the release operation switch is not pressed (OFF), the process proceeds to step S5 to determine whether the servo control is being performed, and if the servo control is being performed, the process of releasing the brake 7 in step S6 is performed. Return to S1. As a result, the brake 7 is kept released during the servo control. If the state is other than the servo control in S5, S5
The process of locking the brake 7 is performed, and the process returns to S1 to determine the operating state of the release operation switch later. In the above description, the brake release time setting section 9 and the brake lock time setting section 10 are configured to be assigned to the memory of the central processing unit 2 as parameters of the robot control device. The setting of the release / lock time of the brake 7 may be changed by a volume or the like. In the above description, the brake release switch is arranged on the operation unit 1. However, the brake release switch may be provided on the periphery of the robot arm, on the robot body, or on the operation box at hand. [0013] [Effect of the Invention] The present invention, which is configured as described above, the brake cancel directive is generated from the operation unit
During this time, the brake release and lock operations can be performed intermittently according to the setting values of the brake release time setting section and lock time setting section. This has the effect of allowing fine adjustment and smooth movement.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a robot control device according to a first embodiment of the present invention. FIG. 2 is a flowchart of a brake control according to the first embodiment of the present invention. FIG. 3 is a state diagram showing a brake operation according to the first embodiment of the present invention. FIG. 4 is a state diagram showing a conventional braking operation. [Description of Signs] 1 Operation unit 2 Central processing unit 3 Servo control unit 4 Servo amplifier unit 5 Motor 6 Position detector 7 Brake 8 Brake control unit 9 Release time setting unit 10 Lock time setting unit 11 Brake driving unit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-92288 (JP, A) JP-A-62-164112 (JP, A) JP-A-59-64281 (JP, A) (58) Investigation Field (Int.Cl. ⁷ , DB name) B25J 19/00 B25J 13/00 G05B 19/18

Claims (1)

(57) Claims 1. A robot equipped with a brake device for controlling the position of a robot arm by operation of a servo control system and braking the robot arm when the servo control system is not operating. The control device includes a lock time setting unit that locks the brake device for a predetermined time, and a release time setting unit that releases the brake device for a predetermined time, wherein the lock is performed while a brake release command is issued from the operation unit. A control device for a robot, comprising: a brake control unit that alternately locks and releases the brake device according to a time set by a time setting unit and the release time setting unit.