JPH0570161B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a robot with a control system that moves from point to point, and which enables easy and high-speed pick-and-place work without complicated arithmetic control. The present invention relates to a robot control device that is capable of controlling a robot.

[Background of the invention]

In conventional point movement control type robots, closed loop control is used between the control system and the drive system for each joint angle of the robot, and the next predicted angle is calculated at each sampling time. According to this method, it is necessary to calculate a large number of predicted angles according to a preset acceleration/deceleration curve in accordance with a very short sampling time, and a high-speed, high-performance microprocessor is required as a control device. The drawbacks were that the control software was complex and large in scale. Also,
A servo motor is used as the arm drive actuator, and to increase positioning accuracy, it is necessary to use a high-resolution pulse generator or a reducer with a large reduction ratio to allow the motor to rotate at high speed. First, the control device becomes complicated, and it is difficult to independently control the vertical direction even in pick-and-place operations.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned drawbacks, and is intended to enable a point-moving robot to perform pick-and-place work easily and quickly without performing complex arithmetic control. .

[Summary of the invention]

In order to achieve the above purpose, a vertical drive shaft that operates in the vertical direction and a horizontal drive shaft that operates in the horizontal direction are provided, and when moving from the current point to the next target point,
The vertical drive shaft is operated prior to the operation of the horizontal drive shaft, and the horizontal drive shaft is operated in parallel with the remaining shift amount from the middle of the vertical drive shaft's operation for the set shift amount. This system is used as an operation control device for robots that are operated as follows.

[Embodiments of the invention]

The present invention will be explained below with reference to an embodiment shown in FIGS. 1 to 4. First, a control unit cabinet 2 made of metal is placed on a control unit base 1 made of a steel plate, the mechanism of which will be explained with reference to FIGS. The cabinet 2 has a metal partition plate 5 that divides the internal space into a control room 3 and a power supply room 4. The control room 3 is sealed by a base 1, a cabinet 2, and a partition plate 5. A board 8 having a microcomputer 6 is arranged within the control room 3 . The heat radiation chamber 4 of the cabinet 2 has a ventilation opening 2a, and the power supply chamber 4 has a power supply chamber 10 such as a transformer and a fan 11. The fan 11 is for forcibly cooling the power supply unit 10, but it also cools the metal partition plate 5 at the same time, so even if the control room 3 is sealed, the interior of the room can be sufficiently cooled. . Therefore, the inside of the control room 3 can be sealed to prevent dust from entering, and the reliability of the microcomputer 6 inside the control room 3 can be improved.

A first drive chamber cabinet 12 made of iron plate is fixedly attached to the control unit cabinet 2,
A first drive chamber 13 is configured. This cabinet 1
2, a first arm 14 is placed horizontally and rotatably. A first drive device 15 for driving the first arm 14 is provided within the first drive chamber 13 . It consists of a first drive motor 16, a first lower belt 17, a first transmission device 18, and a first upper belt 19. The first drive motor 16 is a stepping motor, and is fixed to the cabinet 12 via a support plate 20 so that a rotating shaft 16a projects upward. The first transmission device 18 has a central rotating shaft 18a rotatably supported by upper and lower bearing portions 21a and 21b of a U-shaped support plate 21, and a large first lower disk 18b fixed to the lower portion. A small first upper disc 18c is fixed to the upper part. The first lower belt 17 is the first drive motor rotating shaft 16a.
and the first lower disc 18b. The first upper belt 9 is provided astride the first upper disk 18c and the first arm rotation shaft disk 22a. The first arm 14 is the first lower arm 1
4a and the first upper arm 14b are fixed with screws 14c. This first lower arm 1
4a and the first upper arm 14b are made lightweight by plastic injection molding, which greatly helps to reduce the capacity of the first drive motor 16. In addition, since the first lower arm 14a and the first upper arm 14b are manufactured to have a substantially U-shaped cross section, they are strong in strength, and the first upper arm 14b
By removing it, the internal equipment can be easily repaired. A rotating shaft 22 is fixed to the lower surface of one end of the first arm 14 . This rotating shaft 22 protrudes into the cabinet 12, and
It is rotatably supported by an upper bearing 23 on the upper surface of the cabinet 12 and a lower bearing 24 inside the cabinet 12. The lower bearing 24 is fixed to the cabinet 12 via a support plate 25. 1st
A large disk 22a is located at the center of the arm rotation shaft 22.
is fixed. Therefore, the first drive motor 16
When the rotation shaft 16a is driven, the rotation of the rotation shaft 16a is transmitted to the transmission device 18 via the first lower belt 17,
It is further transmitted to the rotating shaft 22 via the first upper belt 19, whereby the first arm 14 rotates at a slower speed than the rotation of the first drive motor 16. Furthermore, the first
The drive motor 16 is disposed directly below the first arm rotation shaft 22, and the first transmission device 15 is disposed side by side with the drive motor 16, and is housed in the cabinet 12 in a compact manner. A second drive device 27 for driving the second arm 26 is provided within the first arm 14 . The second arm 26 is connected to the first arm 26.
Together with the arm 14, it constitutes a horizontal drive shaft that operates in the horizontal direction. The second drive device 27 includes a second drive motor 28, a second lower belt 29, a second transmission device 30, and a second upper belt 31. Second
The drive motor 28 uses a stepping motor,
It is placed on the first lower arm 14a via the support plate 32. Rotating shaft 28 of second drive motor 28
a protrudes downward. The second transmission device 30 includes a shaft 30a fixed to the first lower arm 14a, and a first lower disc 30b and a second upper disc 30c rotatably supported by the shaft 30a. The second lower disc 30b has a large diameter, and the second upper disc 30c has a small diameter. The second lower belt 29 is provided astride the second drive motor rotating shaft 28a and the second lower disc 30b. The second upper belt 31 includes a second upper disc 30c and a second arm rotation shaft disc 33a.
It is set up astride. Second arm 26
are the second lower arm 26a and the second upper arm 26b.
It is composed of. This second lower arm 26
A and the second upper arm 26b are made lightweight by plastic injection molding, which greatly contributes to reducing the capacity of the second drive motor 28. Further, since the second lower arm 26a and the second upper arm 26b are manufactured to have a substantially U-shaped cross section, they are strong in strength, and the second upper arm 26b
By removing it, the internal equipment can be easily repaired. One end of the second arm 26 is inserted into the other end opening 14d of the first arm 14. A rotating shaft 33 is attached to one end of the second arm 26 and extends vertically through the shaft.
This rotating shaft 33 is connected to the upper and lower bearing portion 14 of the first arm.
e, 14f, and has a large-diameter disk 33a at its center. When the second drive motor 28 is driven, the rotation of the rotation shaft 28a is transmitted to the second transmission device 30 via the second lower belt 29.
is further transmitted to the rotating shaft 33 via the second upper belt 31, and thereby the second arm 2
6 rotates at a slower speed than the rotation of the second drive motor 28. Since the rotation of the second drive motor 28 is transmitted to the second arm via the second transmission device 30, the size of the disk 33a of the second arm rotation shaft 33 can be reduced, and the first arm 14 Also, the outer diameter of the second arm 26 can be reduced.

A third drive device 35 is provided within the second arm 26 for driving a vertical motion shaft 34 that is a vertical drive shaft that operates in the vertical direction. The third drive device 35 consists of a third drive motor 36 and a third gear 37. The third drive motor 36 uses a stepping motor and is fixed to the rib 26c of the second lower arm 26a. A rotating shaft 36a of the third drive motor 36 projects laterally. The third gear 37 is rotatably supported at both ends by one end 26d of the second lower arm 26a and the rib 26e, and is adapted to mesh with the unevenness of the vertical movement shaft 34. Third
Gear 37 is connected to third drive motor 36.

The vertically moving shaft 34 passes through the second arm 26 and is supported via support devices 39 and 40 so as to be vertically movable. This vertical movement shaft 34 is covered with a bellows member 43. The fourth drive motor 41 is connected to the vertical movement shaft 34
is fixed to the lower end of the rotary shaft 41a, and its rotating shaft 41a protrudes downward. A gripper 42 is attached to this rotating shaft 41a.
Attach work tools such as the following to move parts, etc.

Next, the control portion will be explained with reference to FIG. The order control unit 51 instructs the next target point according to the taught order. The motion control unit 52 adjusts the rotation angle of each axis of one to three axes (corresponding to the first to third drive motors 16, 28, and 36 in FIG. 2) necessary to move to the taught target point. Store the corresponding absolute pulse number. In addition, when moving the arm to a target point instructed by the sequence control unit 51, the difference in the absolute number of pulses between the target point and the current point is calculated and output. Thereafter, the target point pulse number is set as the current point pulse number. A drive control section 53, provided independently for each axis, outputs the number of pulses sent from the operation control section 52 in phase so as to rotate while performing acceleration/deceleration control. The excitation driver 54 converts the phase output from the drive control section 53 into electric power sufficient to rotate the motor. 55 is an actuator such as a stepping motor, which rotates each axis by a specified angle. That is, when the robot's hand moves from point 61 to point 62 in FIG. 4, the order control section 51 sends a signal indicating the target point 62 to the motion control section 52 from the memory of the order. The motion control unit 52 extracts the absolute number of pulses for each axis at point 61, which is the current point, and point 62, which is the target point, from memory, and calculates, by subtraction, how many pulses and in which direction to rotate for each axis. The results are output to the drive control section 53 for each axis.

Furthermore, in this operation control device, in a pick-and-place operation such as inserting a workpiece through points 61 and 62 into 63 using a gripper as shown in FIG. 4, the upper position 61 of the workpiece 60 position (point 1) Point U1 and the upper position 62 of the insertion position 63 (point 2) can be specified as point U2, so when teaching the position, it is enough to teach points 60 and 63 as points 1 and 2, and it is also possible to Operation control unit 5 in the figure
The vertical movement axis 34 is connected to the drive control unit 53 for 2 to 3 axes.
This can be achieved by simply outputting the number of pulses modified by the number of pulses corresponding to the amount of upward shift (see FIG. 2). Furthermore, by being able to change the number of pulses to be shifted, it is possible to widely cope with insertion of long workpieces, upward detours of obstacles, etc. However, if the upper limit is exceeded when shifted, this is detected during subtraction and the number of pulses is corrected. In addition, a timer corresponding to the amount of shift is provided, and after outputting the number of pulses to the drive control unit 53 of the three axes, the output of the number of pulses to the 1st, 2nd, and 4th axes is delayed until the timer counts up. advance operation is possible. That is, in assembly work or pick-and-place work, the workpiece 60 is held at the workpiece 60 position shown in FIG. Move to point 62, then point 6 below
The basic operation is to move to 3 and release the workpiece.
Then, when moving from the workpiece 60 position to point 61 → point 62, the vertical movement axis 3 moves upward by the amount set in the shift amount without teaching point 61.
Since the other axes are operated after the movement of point 4, there is no need to teach point 61, and since the object passes near point 61 without stopping, the travel time can also be shortened. The reason why the vertical movement shaft 34 moves upward toward the point 61 is to bypass obstacles, so it is sufficient to pass near the point 61, and there is no need for complicated control. Easy assembly work or pick-and-place work can be realized.

〔Effect of the invention〕

According to the present invention, the control device that controls the operation of the horizontal drive shaft and the vertical drive shaft by controlling the motor has a timer that sets a time corresponding to the amount of upward shift of the vertical drive shaft, When moving the work tool from the current point to the target point, the operation of the horizontal drive axis is delayed and the vertical drive axis is operated in advance within the time set by the timer, and after the time set by the timer elapses, the above operation is performed. Since the horizontal drive axis is operated in the middle of the vertical drive axis' operation for the set shift amount and in parallel with the operation for the remaining shift amount, it is possible to speed up the work without using complicated arithmetic control. In addition, it was possible to shift the vertical drive shaft upward, which is necessary for pick-and-place work, without using complicated calculation control. In addition, even if the length of the workpiece or the height of an obstacle changes, this can be handled simply by changing the timer setting.

[Brief explanation of the drawing]

Fig. 1 is an external view of a scalar type robot using this control device, Fig. 2 is a vertical sectional view of the same robot, Fig. 3 is a schematic configuration diagram of this operation control device, and Fig. 4 is a diagram of a scalar type robot using this control device. FIG. 3 is an explanatory diagram of a control method. 51...Sequence control section in this control device, 52...Operation control section, 53...Drive control section, 54...Driver, 5
5... Actuator, 60... Work or its position in the work example, 61... Position for lifting the work, 62... Position above the insertion position before inserting the work, 63... Target insertion point of the work.

Claims (1)

[Claims] 1. A vertical drive shaft that operates in the vertical direction, a working tool attached to the tip of the vertical drive shaft, a horizontal drive shaft that operates in the horizontal direction, and a plurality of drive shafts that drive both of the drive shafts. a motor, and a control device that controls the motor to control the operation of both of the drive shafts, and the control device has a timer that sets a time corresponding to the amount of upward movement of the vertical drive shaft. do,
When moving the work tool from the current point to the target point, the operation of the horizontal drive axis is delayed and the vertical drive axis is operated in advance within the time set by the timer, and after the time set by the timer has elapsed, A robot characterized in that the horizontal drive shaft is operated from the middle of the operation of the vertical drive shaft for a set shift amount in parallel with the operation for the remaining shift amount.