JP2799952B2 - Manipulator safe operation system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial robot, and more particularly, to an industrial robot when an operator accidentally enters an operation area of the industrial robot during operation of the industrial robot. The present invention relates to a safe operation system of a manipulator that does not cause danger even if actuated.

[0002]

2. Description of the Related Art Generally, an industrial robot has a function of performing various operations in a three-dimensional space, and mainly controls an arbitrary movement of an object in a production activity.
At present, it has a movement function with a high degree of freedom similar to the movement function of a human upper limb (arm or hand), or can act autonomously by a sensory function and a recognition function. This industrial robot has a work area that is a work space that can perform work normally without any obstacles in moving the arm, but unlike general machines, the range of action of the arm is wide, and Although high speed, motion paths, and accuracy of the stop position are required, the entire system including the arms of the industrial robot has high rigidity, so that safety measures against the movement of the robot are required.

[0003] When an industrial robot is installed and used, when a worker enters the operation area of the industrial robot to perform work, danger due to unexpected operation of the robot and danger due to malfunction of an operator are pointed out. ing.
For this reason, in general, when an industrial robot is operating, it is strictly restricted by occupational safety and health regulations that workers enter the operating area of the industrial robot. In addition, it is mandatory for a person who grounds and uses an industrial robot to take many safety measures so as not to cause harm to an operator even if an unexpected operation of the robot or a malfunction of an operator occurs. Therefore, it is unlikely in Japan that working in the operation area of an industrial robot while the industrial robot is in operation without taking safety measures. However, in the outer space, for example, an astronaut performs an artificial satellite recovery operation in cooperation with the manipulator in the operation area of the manipulator of the NASA space shuttle in the United States.

As described above, in cosmic space, even when an astronaut works in the operation area of the manipulator, even when moving a luggage weighing more than 10 tons because the space is zero gravity, each joint of the manipulator can be moved. The prime mover is 6
An output of 0 W or less is sufficient. As described above, in the outer space, since the operation motor used to move the luggage is small, even if the manipulator operates unexpectedly, the acceleration is small, and there is no danger due to the unexpected operation. Japanese Patent Publication No. Sho 59-351 discloses a conventional industrial robot for maintaining a zero gravity state. In this mechanism, a servo actuator for driving a vertical movement mechanism for maintaining a zero gravity state is driven by pneumatic pressure, and a piston of the servo actuator is controlled by another drive motor in order to enhance positioning accuracy.

[0005]

On the other hand, on the ground, unlike the universe, the gravity of the industrial robot and its transferred object is not in a zero-gravity state. A prime mover with a large output is needed just to maintain the power. For this reason, when the industrial robot operates without the transferred object or when the weight of the industrial robot moves in a direction that assists the operation, the prime mover may exert a large force due to malfunction, and There is a problem that a worker who enters the operation area of the robot and works may pose a danger. Further, in the case of the above-mentioned conventional industrial robot (Japanese Patent Publication No. 59-351), the output is almost the same as that of a normal industrial robot, and it cannot be a safe robot. have. Further, in the conventional industrial robot, the longitudinal movement mechanism is
It has the same structure as the vertical movement mechanism, but its drive servo actuator does not have the function of maintaining the front and rear balance, it is performed by another vertical balance mechanism, and the front and rear balance is incomplete with this method There is a problem that.

SUMMARY OF THE INVENTION It is an object of the present invention to maintain the weight of an industrial robot or the weight of a transferred object by another means, instead of using the power for operating the industrial robot. The weight of the industrial robot itself and the weight of the transferred object is reduced to zero gravity by a balance device that minimizes the output of the prime mover that obtains the power to perform the operation, and the operator enters the operating area of the industrial robot during the operation of the industrial robot. Even if a worker enters and works, even if there is a sudden operation of the robot or a malfunction of the operator, it is intended to avoid danger to the operator.

[0007]

In order to achieve the above object, in a manipulator safe operation system according to the present invention, a first arm for suspending a load at a tip thereof, and one end thereof being turned at a distal end of the first arm. A second arm movably supported on the first arm, a first parallel link having one end rotatably supported on the first arm and arranged parallel to the second arm, and a first parallel link; A second end is rotatably supported at the end of the link and the other end is rotatably supported at an appropriate position of the second arm and is disposed so as to be parallel to the first arm.
A parallel link, a front-rear cylinder suspended between the first parallel link and the second parallel link for controlling the balance in the front-rear direction of the load, and mounted on a distal end of the second arm to vertically move the distal end of the second arm Up and down cylinders
A first electric servomotor for tilting the second arm back and forth; a second electric servomotor for moving the load up and down with respect to the second arm; and a drive mechanism for turning the first arm. , The weight of the arm and the weight of the load, the tip a of the first arm, the first arm and the second
A pivot fulcrum c with the arm and a movement fulcrum B at the end of the second arm
△ acB, a moving shaft fulcrum A where the end of the first parallel link and one end of the second parallel link are connected and supported, a shaft fulcrum b between the second parallel link and the second arm, ΔA formed by the moving fulcrum B at the end of the two arms
bB is always balanced by the front and rear cylinders and the vertical cylinder so as to form a similar triangle so that the load stays at an arbitrary position, and the vertical and vertical rotation of the load is controlled by the first electric motor. A servo motor,
This is performed by the second electric servomotor and the drive mechanism.

[0008]

In a manipulator that moves in a three-dimensional space by gripping a load, the holding device is independent of the holding device by a position control device that is independent of a holding device of two or more axes that detects the load and the gravity of the manipulator and controls the force. Control of the two or more driving devices described above, the weight of the industrial robot's own weight and the weight of the transferred object are not held by power to operate but are held by another means, and the prime mover is used for operation. To the minimum output, and even if an operator enters the operating area of the industrial robot during the operation of the industrial robot, the weight of the industrial robot itself and the weight of the moving object are balanced to make it zero-gravity. Work around.

[0009]

Embodiments of the present invention will be described below. FIG. 1 shows an embodiment of a safe operation system for a manipulator according to the present invention.

In FIG. 1, reference numeral 1 denotes an arm mechanism which stops and holds a load 3 at an arbitrary position and can freely move to an arbitrary position. Reference numeral 2 denotes an arm supporting portion that rotatably supports the arm mechanism 1 around a pivot shaft. 3 is load, 4
Is a vertical cylinder for moving the arm mechanism 1 up and down. 5 is a first arm and 6 is a second arm. The first arm 5 has a load 3 suspended from the distal end, and the distal end is pivotally supported at one end of the second arm 6, and forms a part of the arm mechanism 1. The end of the second arm 6 is rotatably supported by the cylinder rod of the vertical cylinder 4 so that the second arm 6 slides vertically in the slit formed in the arm support 2 by the vertical cylinder 4. It has become. Reference numeral 7 denotes a first parallel link. One end of the first parallel link 7 is rotatably supported at an appropriate position of the second arm 6, and the end of the first parallel link 7 is rotated by one end of a second parallel link 13. It is freely supported. The first parallel link 7 is disposed so as to be always kept parallel to the second arm 6. Reference numeral 8 denotes a front-rear cylinder suspended between the first parallel link 7 and the second parallel link 13 to balance the arm mechanism 1 in the front-rear direction. Reference numeral 9 denotes a pilot pressure reducing valve that controls the pressure of the vertical cylinder 4, and reference numeral 10 denotes a pilot pressure reducing valve that controls the pressure of the front and rear cylinders 8.

The vertical cylinder 4 supports the weight of the load 3 (1/3 of the load 3) in proportion to the ratio of the line segment aB (for example, 3) to the line segment AB (for example, 1). Has the function of balancing the load 3 so that the load 3 is held at an arbitrary position. Pilot type pressure reducing valve 9
Detects the output of the vertical cylinder 4 required to hold the load 3 suspended at the tip of the first arm 5 at an arbitrary position, by converting the output into the pressure in the vertical cylinder 4 and detecting the output. The pressure in the cylinder 4 is controlled.

The front and rear cylinders 8 are attached to the second parallel link 13, and the cylinder rod of the front and rear cylinders 8 is attached to the first parallel link 7. The front and rear cylinders 8 are balanced so that the arm mechanism 1 outputs a force repelling the force of the arm mechanism 1 to move in the front and rear direction so that the arm mechanism 1 is held at an arbitrary position. The valve 10 uses the pressure in the cylinders of the front and rear cylinders 8 as a pilot pressure as the arm mechanism 1.
Is controlled to prevent the air from flowing in the front-rear direction.

Reference numeral 11 denotes a first electric servo motor for tilting the second arm 6 back and forth. Reference numeral 12 denotes a second electric servomotor for moving the load 3 up and down with respect to the second arm 6. Reference numeral 13 denotes a second parallel link that constitutes the arm mechanism 1, and one end of the second parallel link is the first parallel link.
The end of the parallel link 7 is rotatably supported by a shaft. The terminal of the second parallel link 13 is rotatably supported at an appropriate position on the second arm 6.
Is rotatably supported at an appropriate position on the second arm 6 where the second parallel link 13 is parallel to the first arm 5. The length of the second parallel link 13 is such that the first parallel link 7 is parallel to the second arm 6.

In the arm mechanism 1, the first arm 5, the second arm 6, the first parallel link 7, and the second parallel link 13 form a parallelogram link. A is a moving shaft fulcrum that supports the arm mechanism 1 and moves back and forth. B is a fulcrum at the tip of the second arm 6, which supports the load 3 and slides up and down. Further, b is a pivot point at which the second parallel link 13 is rotatably supported by the second arm 6, and is provided at a position where the second parallel link 13 extends parallel to the first arm 5. Then, the distal end a of the first arm 5, the distal end of the first parallel link 7, and the second
Moving shaft fulcrum A at which one end of the parallel link 13 is connected and supported.
And the moving fulcrum B at the end of the second arm 6 is configured to always be on a straight line regardless of the position of the load 3. Further, the tip a of the first arm 5, the pivot fulcrum c between the first arm 5 and the second arm 6, and the movement fulcrum B at the end of the second arm 6
△ acB, a moving shaft fulcrum A where the end of the first parallel link 7 and one end of the second parallel link 13 are connected and supported, and a shaft fulcrum between the second parallel link 13 and the second arm 6. b and ΔAbB formed by the moving fulcrum B at the end of the second arm 6 always form a similar triangle.

Reference numeral 14 denotes a pneumatic pressure source, which is a pilot pressure reducing valve 9,
Supply 10 its power. Reference numeral 15 denotes a control device.
The second electric servomotors 11 and 12 are controlled. Reference numeral 16 denotes a control circuit of the control device 15, to which a computer 17, a teaching device 18, and a power supply 19 are connected. Reference numerals 20, 21, and 22 denote servo amplifiers, respectively. The servo amplifier 20 includes the first electric servomotor 11, the servo amplifier 21 includes the second electric servomotor 12, and the servo amplifier 22 includes a swing incorporated in the arm support 2. For driving the respective driving mechanisms. 23, 24,
25 is a feedback circuit. One end of the feedback circuit 23 is connected to the first electric servomotor 11 and the other end is connected to the position detector.
Has one end connected to the second electric servomotor 12 and the other end connected to the position detector, the feedback circuit 25 has one end connected to the arm support 2 and the other end connected to the position detector,
Each of the positions is detected.

Next, the operation of this embodiment will be described.

First, when the pneumatic pressure source 14 is turned on, the vertical cylinder 4 generates a force proportional to the load 3 and balances at that position. Subsequently, the front and rear cylinders 8 balance at a given position. If the operator moves the tip with the arm mechanism 1, it can be moved without feeling the weight of the load 3. Next, when the power supply 19 of the control device 15 is turned on and operation commands are given to the first and second electric servomotors 11 and 12 by the teaching device 18, the arm mechanism 1 moves up and down, back and forth, Perform the turning operation.

When a teaching command is given at the position moved based on the above command, the position is input to the control circuit 16 via feedback circuits 23, 24 and 25 connected to the position detector and stored in the storage device of the computer 17. Is done. The operation procedure and the position of the arm mechanism 1 stored in this manner constitute a series of programs. By playing back such a program, the arm mechanism 1 is automatically operated. Therefore, according to the present embodiment, the arm mechanism 1 is completely balanced by the vertical cylinders 4 and the front and rear cylinders 8 and then is different from the three driving devices (the first electric servomotor). 11, the second electric servomotor 12, and the drive mechanism built into the arm support section 2) can move the tip of the arm mechanism 1 to the three-dimensional space.

Further, since the driving device shown in FIG. 1 is configured to drive the arm mechanism 1 after it is completely balanced, it is not necessary to hold the weight of the load 3 or the weight of the arm mechanism 1, and It can be moved with small power like a space shuttle manipulator in space. Furthermore, if all three driving devices are about 60W like the manipulator of the Space Shuttle, there is no danger even if they come into contact with humans, and because of the small power, sudden changes that humans can not predict. Nor.

Further, the vertical cylinders 4 and 3
Since the force control and the position control of each of the three drive units are independent control devices, unless at least two of the three independent control devices malfunction at the same time,
It does not perform complicated movements that can be expected by humans, and does not suddenly. As described above, according to the present invention, safety can be ensured even when a person enters the operation area of the arm mechanism 1. Further, by ensuring such safety, the worker can work in cooperation with the arm mechanism 1, and the effect can be improved as a team having both the flexible work of the worker and the ability of the arm mechanism 1 as a strong man. it can.

Further, in order to temporarily recover the function of the physical disability, the gait training is performed by having the arm mechanism 1 hold 90% to 30% of the weight of the patient and moving the patient according to the program. Can also. In addition,
It can be effective as various robots that coexist with humans, such as rescue activities in disaster areas, contact with humans for security, and service businesses.

[0022]

According to the present invention, in a manipulator that moves in a three-dimensional space while gripping a load, a position independent of a holding device having two or more axes that controls the force by detecting the load and the gravity of the manipulator. Since the control device controls two or more driving devices independent of the holding device, the self-weight of the industrial robot and the weight of the transferred object are controlled by power (front and rear cylinders and vertical cylinders) to operate. Without the holding, it is held by another means (the first electric servomotor, the second electric servomotor, and the driving mechanism), and the prime mover is set to the minimum output for the operation. When the worker enters the operation area, the weight of the industrial robot itself and the weight of the moving object are balanced to reduce the weight of the robot, thereby avoiding the danger to the worker.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing an embodiment of a manipulator safe operation system according to the present invention.

[Explanation of symbols]

1 ………………………………………………………………………………………………………………………………………………………. ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………………… Second arm 7… ………………………… First parallel link 8 ………………………………………………………………………………………………… 9 ………………………… Pilot pressure reducing valve 11 ……………………………………………………………………………………………………………………………………………………………………………………………………………… ··························································································································· | ………………………………………………………………………………………………………………………………………………… 13 ……………………………………………………………………………………………………………………………… pneumatic source 15 ………………………………… ………………………………………………………………………………………………………………………………………………………… Control circuit 17 ………………………………………… ...... Calculator 18 .................. Teaching device 19 ...... Power supply 20, Power supply 20, 21, 22 …………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………… A …………………………………………………………………………………………………………………………… Movement points c …………………… ……………………… Axial fulcrum

Claims (1)

(57) [Claims] 1. A first arm for suspending a load at a tip, a second arm having one end rotatably supported at a distal end of the first arm, and one end rotatably supported by the first arm. A first parallel link that is pivotally supported on the second arm and that is rotatably supported at an end of the first parallel link and that has the other end pivoted at an appropriate position on the second arm; A second parallel link movably supported to be parallel to the first arm, before and after the first parallel link and the second parallel link are suspended from the first and second parallel links to control the balance of the load in the front and rear direction; A cylinder, a vertical cylinder attached to a distal end of the second arm for vertically moving the distal end of the second arm, a first electric servomotor for tilting the second arm back and forth, Moving the load up and down And a drive mechanism for rotating the first arm, the weight of the arm mechanism's own weight and the load being measured by the tip a of the first arm and the fulcrum of the first arm and the second arm. c
△ acB formed by a moving fulcrum B at the end of the second arm, a moving shaft fulcrum A where the end of the first parallel link and one end of the second parallel link are connected and supported, and a second parallel link. The front and rear cylinders and the vertical cylinder are balanced so that the △ AbB formed by the pivot fulcrum b with the second arm and the movement fulcrum B at the end of the second arm always forms a similar triangle. The first and second electric servomotors, the second electric servomotor, and the drive mechanism are configured to stop at an arbitrary position and to perform up / down, forward / backward, and turning of the load by the driving mechanism. Manipulator safe operation system.