JPS6057407A - Robot controller - Google Patents

Abstract

PURPOSE:To increase the working speed of a robot by driving an arm in accordance with an acceleration/deceleration curve obtained by selecting plural acceleration/deceleration curves on the basis of the results of detection on the arm posture before drive and the arm expected posture after drive respectively. CONSTITUTION:When a drive command 9 is given, a present arm posture detecting means 10 detects the present position of the 2nd arm among areas 6-8. Then acceleration curves 14-16 are selected respectively. The position of the 2nd arm after drive is expected by an arm posture detecting means 11 after drive among those areas 6-8. Then deceleration curves 17-19 are selected respectively. These acceleration and deceleration curves are selected from memories 12 and 13 and added together to produce an acceleration/deceleration curve 21. A controller delivers a drive pulse in response to the curve 21 to drive the robot arm.

Description

[Detailed description of the invention] The present invention relates to a robot controller for assembling beans.

SUMMARY OF THE INVENTION An object of the present invention is to shorten the acceleration/deceleration time and speed up the robot without adversely affecting the life of the robot.

In order to speed up a robot, it is common practice to make the arm lighter, make the bearing structure more robust, or modify the acceleration/deceleration curve, but conventional robot controllers simply Since it only had one acceleration/deceleration curve, once the travel distance was determined, regardless of the arm's posture, the travel time was also determined. In other words, when the arm is fully extended, the impact on the robot increases, which has a negative impact on its lifespan, while when the arm is retracted, the robot's inertia decreases, reducing its speed even though there is plenty of room for load. It had the disadvantage of being exposed.

The present invention eliminates such drawbacks and will be explained below based on examples.

1 in Fig. 1 is a so-called horizontal multi-joint type robot. When the motor 2 rotates, the first arm 3 swings around the motor 2. When the motor 4 rotates, the first arm 3 swings around the motor 4. 2 Arno 5": 4 moves.

The first arm 3 and the second arm 5 are simultaneously controlled 2IlII so that they start moving at the same time and end their movement at the same time even if the driving amounts are different due to DDA calculation or the like.

FIG. 2 is a view of the robot viewed from directly above, showing the operating range of the second arm 5. This operating range is divided into three areas of 6°7.8.

On the other hand, the controller has acceleration curves 14, 15°16 and deceleration curves 17@18.1 with different accelerations, as shown in Figure 6.
9 are stored in the memories 12 and 15, respectively.

When the drive command 9 is generated when driving the arm, the current arm detection means 10 detects that the second arm is currently in the position 6,
7. Detect which area of B is in 7 and select acceleration curves 14, 15, and 16, respectively. Further, the arm posture detection means 11 after driving predicts in which area of 6.7.8 the position of the second arm after driving will be, and selects deceleration curves 17, 18, and 19, respectively, and generates acceleration/deceleration curves. The means 20 generates an acceleration/deceleration curve 21 in combination with the previously selected IJOI speed curve.

The controller can output drive pulses according to the 7JI+deceleration curve 21.

This will be explained using a more specific example.

Assuming that the robot arm is driven from P1 to P2-\ in Figure 4, when the tip of the arm touches Pl, the second arm is in area 7, and the moment of inertia is medium, so the acceleration curve also shows an acceleration. Select 15 which is in the middle, and when the arm tip goes to P2 after driving, the position of the second arm is in area 8 and the moment of inertia is expected to be large, so select 19 with small acceleration for the deceleration curve. do.

As is clear from the above explanation, in the present invention, when the moment of inertia is small, acceleration/deceleration with a large acceleration is performed, and when the moment of inertia is large, acceleration/deceleration with a small acceleration is performed, so that the robot arm can be accelerated/decelerated without giving unnecessary shock to the robot arm. It can save time.

At the same time, in a robot that drives two axes, the drive pulse frequency of each axis differs depending on the ratio of the drive IJJb1t of the first arm and the second arm, as shown in FIG. Here, a is the number of drive pulses for the first arm, and b! "It is divided by the number of driving pulses of the second arm.

In the example of FIG. 5, the impact force applied to the second arm is almost the same in cases (]) and (2), but the impact force applied to the first arm is overwhelmingly smaller in case (2). Therefore, if there is enough margin in the drive of the second arm, the locking in (2) can be achieved even if the total acceleration is increased.

In consideration of the above, FIG. 6 is a further improvement of FIG. 5, in which when an arm drive command 22 is generated, the arm posture detecting means 23 before driving. One of the acceleration curves 25, 26, 27 and deceleration curves 28, 29.50 is selected by the arm posture detection means 24 after driving.
It is similar to FIG. 6, but at the same time, the first arm is driven by the drive comparison means 31. The ratio (a/l) between IdIma and the drive amount of the second arm is calculated, and the size judgment 32 judges the thickness of the result, and if it is less than a certain value, it is further added to the previously selected acceleration curve or deceleration curve. The curve is changed to a curve with a large acceleration of 1st or 2nd ranks to generate an adjustment song @33.

This will be explained based on a specific example.

Figure 7 shows the robot arm being driven from P3 to P4, but since the position of the second arm before and after driving is the same as in Figure 4) 9II, the acceleration curve 26 and the deceleration curve 30 is selected once.

At the same time, set a/b to 91, and if the result is 1/2 or less, change the acceleration/deceleration curve to one with one rank higher acceleration.
If it is 1/4 or less, change 2 ranks. This “convex gold” is 1/
4 (a/b (1/2), so the acceleration curve for one rank up is 25 and the deceleration curve is 29.

The reference values 1/2 and 1/4 used for the comparison of the a/b values are set to optimal values depending on the shape of the acceleration and deceleration curves and the difference in acceleration in each rank.

In Figure 7, the simultaneous control axes were two axes, the first arm and the second arm, but the upper T-axis of the arm and the wrist horizontal rotation axis were added, making it possible to drive three or four axes simultaneously. If
Let a be the number of drive pulses for the first arm, which is most affected by load fluctuations due to changes in arm posture, and for the second arm and the vertical axis.

The calculation may be performed by setting b to the pulse number of the axis with the largest number of drive pulses at that time among the wrist horizontal rotation axes.

Although the horizontal articulated robot has been described above for IZQ, the present invention can also be applied to vertical articulated robots and cylindrical coordinate robots.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a horizontal articulated robot. Fig. 2 is a view of the horizontal multi-branch robot viewed from directly above (ya) showing the operating range of the second arm. Fig. 6 is a view showing an embodiment of the present invention, and Fig. 4 is FIG. 5 is a diagram showing an example of the operation of a robot arm. FIG. 5 is a diagram showing pulse trains distributed in each axis of the first and second arms, and FIG. 6 is a diagram showing an embodiment of the present invention. Fig. 7 is a diagram showing one of the robot arm movements. 1...Horizontal articulated robot 2...First arm swing motor 5...First arm 4...Second arm swing motor 5...Second arm/1,7.8...Second arm area?922
・・・・・・L'I Otsuki command 10.23 ・・・・Current arm posture detection means 11
．． 24...Arm attitude detection means after driving 12.
13... Memory 14.15, 16, 25, 26.27... Acceleration curve 17.18.19.28, 29.30 ・=-・Deceleration curve 20... - Acceleration/deceleration curve generation means 21.23...Acceleration/deceleration curve 61...A/B calculation means 52...A/D size determination means and above Applicant: Suwa Co., Ltd. Seikosha Agent Patent Attorney Mogami Mu Seito Zuyo 1 Ryo-Muyo 2'F-, IA c%) <b Drawing procedure amendment (voluntary) w4., 5)) ,, io Self 2゜1, Indication of the case 1982 Patent Application No. 165576 2 Name of the invention Robot controller 3, Person making the amendment Case Relationship with Applicant Higashijito W [Shuku-ku Nishi 1/R Shuku 2-4-1 (236) Suwa Seikosha Co., Ltd. Representative Director Hisashi Nakamura
No. 4 Agent No. 146-21 Zebashi 2-J' Chuo-ku, Tokyo 104, Hanbe Seiko Co., Ltd. Mogami Patent Office 6, Specification Subject to Amendment Procedure it' Positive τ11 (1st Lab,) 1 , chant#'l
Range of request, complete appendix U] (Amend. 2, Clear clause 1) Page 6, line 3, ``Addition and subtraction 1111.11!53, l and A2)
41闗41111糾53''. s, on 4u+ v4811S line "21.23" is corrected to "21,33J. Range of ship -t 'l"F irFit^ +11 acceleration! 1, 1's acceleration curve m and deceleration curve are memorized, the control device is fixed, and the posture before deworming 11 is determined! lηφ Me 1 Select one of each of the pre-arm postures to be detected and generate an acceleration/deceleration tune #11. c) A robot controller characterized in that: (21.11.￥F, 4 QI]!!! Among the several drive! IIl axes, the influence of the vI load fluctuation due to the change in the arm's appearance is the greatest, and the drive pulse of the crab/kerusuke We have a means to calculate the ratio between the number and the drive force of the other axes7, and the result of this calculation is one step higher, and the lower fit is completed - acceleration that is completely selected by the five postures. A robot controller that selects and faces a speed curve with a larger acceleration voltage as 4-sr+X.

Claims (2)

[Claims] (1) A storage device for storing a plurality of acceleration curves and deceleration curves having different accelerations, a means for detecting an arm posture before driving and a predicted arm posture after driving, and a means for storing a plurality of acceleration curves and deceleration curves having different accelerations, and means for generating an acceleration/deceleration curve by selecting one of a plurality of acceleration and deceleration curves, and driving the arm according to the generated acceleration/deceleration curve. robot controller. (2) A means for calculating the ratio of the number of drive pulses for the axis that is most affected by load fluctuations due to changes in arm posture among multiple drive axes driven simultaneously to the number of drive pulses for the other axes. This i! If the i calculation result is less than a certain value, the robot controller reselects the acceleration and deceleration curves selected according to the arm posture.