CN108582071B - A method of industrial robot programming trajectory diagnosis and speed optimization - Google Patents

Abstract

The invention belongs to the field of industrial robots, and discloses a method for programming trajectory diagnosis and speed optimization of an industrial robot, comprising the following steps: (1) obtaining the original programming code of the motion trajectory of the industrial robot, establishing an industrial robot model, Attribute parameters; (2) Discrete the motion trajectory to form a line segment of equal arc length and obtain a series of discrete points; (3) Invert to obtain the joint coordinates of each discrete point; (4) Calculate the joint velocity at the discrete point , acceleration and torque; (5) Diagnose the area that cannot reach the programmed speed and optimize the speed; (6) Output the programming code after the speed optimization, the programming code is compared with the original programming code, the programming points are added, and the programming is optimized. speed. The invention can realize the speed optimization of the programming trajectory, and obtain the programming code satisfying the robot dynamics. When the actual machine is running, the running time of the robot is shortened and the operation is more stable.

Description

A method of industrial robot programming trajectory diagnosis and speed optimization

technical field

The invention belongs to the field of industrial robots, and more particularly, relates to a method for programming trajectory diagnosis and speed optimization of an industrial robot.

Background technique

There are two ways to program industrial robots: teaching programming and offline programming. Teaching programming is that the operator holds the teaching pendant, manually controls the end of the robot to reach the specified posture and position, records the robot posture data and writes the robot programming instructions. Offline programming is to build a virtual 3D working scene on CAD\CAM software, and then the software can automatically generate the programming code of the robot according to the size, shape and material of the part to be processed, and at the same time cooperate with some operations of the software operator.

No matter which programming method is used, when programming, only the joint limit of the industrial robot is considered in many cases, and whether the programmed trajectory can be run or not is not considered for other limitations (speed, acceleration and torque) of the industrial robot joint. The robot is a complex, highly coupled nonlinear mechanism, and its joint velocities and terminal velocities only have an instantaneous relationship. In actual operation, the robot sometimes does not reach the programmed speed due to one or more joints reaching their property limits.

SUMMARY OF THE INVENTION

Aiming at the above defects or improvement requirements of the prior art, the present invention provides a method for diagnosing and optimizing the speed of industrial robot programming trajectory. Through discrete programming points of equal arc length, the joint speed, acceleration and torque at each point are calculated, Compare with actual joint limits; speed optimization by increasing programming points and changing programming speed to generate programming code that satisfies robot kinematics.

In order to achieve the above object, according to the present invention, a method for diagnosing the programming trajectory and speed optimization of an industrial robot is provided, which is characterized by comprising the following steps:

(1) Obtain the original programming code of the motion trajectory of the industrial robot, establish an industrial robot model, and obtain the attribute parameters of the industrial robot;

(2) Discrete the motion trajectory generated by the original programming code, form line segments of equal arc length and obtain a series of discrete points, set the discrete arc length as an integer multiple of the length of an interpolation cycle, and save the flute of the discrete points. Karl coordinate P(x, y, z, A, B, C), where x, y, z are the coordinates of the origin of the tool coordinate system relative to the workpiece coordinate system, A, B, C are the coordinates of the tool coordinate system relative to the workpiece The pose of the coordinate system;

(3) According to the Cartesian coordinates P(x,y,z,A,B,C) of the discrete points, inversely obtain the joint coordinates J(θ ₁ ,θ ₂ ,θ ₃ ,θ ₄ ,θ ₅ of each discrete point , θ ₆ ), θ ₁ , θ ₂ , θ ₃ , θ ₄ , θ ₅ , θ ₆ are the angles of the industrial robot joint i, i=1, 2…6;

(4) According to the joint coordinates and programming speed at each discrete point, calculate the joint speed, acceleration and torque at each discrete point respectively;

(5) According to the joint speed, acceleration and torque at each discrete point, compare and diagnose with the speed limit, acceleration limit and torque limit of each joint of the industrial robot, and optimize the programming speed for the area that cannot reach the programming speed;

(6) Output speed-optimized programming code. Compared with the original programming code, the programming code increases programming points and optimizes the programming speed.

Preferably, the concrete process of comparing and diagnosing in step (5) is as follows:

Taking every two programming points of the motion trajectory generated by the original programming code as the benchmark, if all discrete points between these two programming points do not exceed the speed limit, acceleration limit and torque limit of each joint, the programming code will remain unchanged;

If there are discrete points between these two programming points that exceed the speed limit, acceleration limit, and torque limit of each joint, the programming speed optimization is performed as follows: Insert a new programming point between the two programming points, program the two The motion trajectory between the points is segmented, and the new programmed points coincide with discrete points that just exceed the speed limit, acceleration limit, and torque limit of each joint, and the minimum value of the maximum linear speed allowed for each segment is set as this segment. programming speed.

Preferably, the programming speed is increased to a suitable value for programming points that do not exceed practical limits and allow increased speed.

Preferably, the attribute parameters include DH parameters, workpiece coordinate system, tool coordinate system, speed limit, acceleration limit and torque limit of each joint of the industrial robot.

In general, compared with the prior art, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

This method obtains the joint speed, acceleration and torque information at the point from the perspective of the programming trajectory and the discrete programming trajectory of equal arc length. Compared with the actual limit of the joint, the programming trajectory is increased by adding programming points and changing the programming speed. Speed optimization to get programming code that satisfies robot dynamics. When the actual machine is running, the running time of the robot is shortened and the operation is more stable.

Description of drawings

Fig. 1 is the flow chart of the invention;

Fig. 2 is the trajectory diagram of joint 1;

Fig. 3 is the velocity diagram of joint 1;

Figure 4 is the acceleration diagram of joint 1;

Fig. 5 is the moment diagram of joint 1;

Figure 6 is an example diagram of insert programming points.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

1 to 6, a method for programming trajectory diagnosis and speed optimization of an industrial robot includes the following steps:

(1) Obtain the original programming code of the motion trajectory of the industrial robot, establish an industrial robot model, and obtain the attribute parameters of the industrial robot;

(2) Discrete the motion trajectory generated by the original programming code, form line segments of equal arc length and obtain a series of discrete points, set the discrete arc length as an integer multiple of the length of an interpolation cycle, and save the flute of the discrete points. Karl coordinate P(x,y,z,A,B,C);

(3) According to the Cartesian coordinates P(x,y,z,A,B,C) of the discrete points, inversely obtain the joint coordinates J(θ ₁ ,θ ₂ ,θ ₃ ,θ ₄ ,θ ₅ of each discrete point ,θ ₆ ), where x, y, z are the coordinates of the origin of the tool coordinate system relative to the workpiece coordinate system, A, B, C are the poses of the tool coordinate system relative to the workpiece coordinate system, θ ₁ , θ ₂ , θ ₃ , θ ₄ , θ ₅ , θ ₆ are the angles of each joint of the industrial robot;

(4) according to the joint coordinates at the discrete point and the programming speed, calculate the joint speed, acceleration and torque at the discrete point respectively; wherein, the programming speed is the linear speed under the Cartesian space;

(5) According to the joint speed, acceleration and torque at discrete points, compare with the speed limit, acceleration limit and torque limit of each joint of the industrial robot, diagnose the area that cannot reach the programmed speed and perform speed optimization;

(6) Output speed-optimized programming code. Compared with the original programming code, the programming code increases programming points and optimizes the programming speed.

Further, the speed optimization process in step (5) is as follows:

Always take every two programming points of the motion trajectory generated by the original programming code as the benchmark. If all the discrete points between the original two programming points do not exceed the limit, the programming code will not be changed. If there are discrete points between the original two programmed points that exceed the speed limit, acceleration limit and torque limit of each joint, insert a new programmed point between the two programmed points, and compare the motion trajectory between the two programmed points. Segmentation is performed, the new programmed point coincides with the discrete points just exceeding the speed limit, acceleration limit and torque limit of each joint, and the minimum value of the maximum linear speed allowed for each segment is set as the programmed speed of this segment. Referring to FIG. ₆ , the original programming points are P1 and _P2 , and the original programming speed is set as v. Since there are points that exceed the limit for discrete points, calculate the maximum allowable linear velocity. When speed optimization is performed, the trajectory is segmented, and new programmed points _P3 , P4, and _P5 are inserted _{. The} positions of _P3 , P4, and _P5 are discrete from the speed limit, acceleration limit, and torque limit of each joint that just exceeds the limit. _The point positions coincide, _P3 , P4 and _P5 divide the _P1P2 track into _four segments, and set the programming speed _of each segment to the minimum value of the maximum linear speed allowed in this segment, that is, the programming speed of the _P1P3 segment is v , the programming speed of _P3P4 segment is v1, the programming speed _{of P4P5 segment} is _v , and the programming speed of _{P5P2 segment} is _v2 .

Further, increase the programming speed to an appropriate value for programming points that do not exceed practical limits and allow increased speed.

Further, the attribute parameters include DH parameters, workpiece coordinate system, tool coordinate system, speed limit, acceleration limit and torque limit of each joint of the industrial robot.

Combining with the specific Wasu HSR-JR605 industrial robot, the methods of programming trajectory diagnosis and speed optimization are as follows:

(1) Obtain the code of offline programming and the attribute parameters of the Huashu HSR-JR605 industrial robot, and use the offline programming software to make the HSR-JR605 robot generate a sinusoidal trajectory on a slope, and the trajectory is reachable by simulation, and the offline programming code is generated. When programming, a constant Cartesian velocity of 100mm/s is given. Get the attribute parameters of the robot, and the actual limits of its joints are shown in the following table.

Table 1 Joint restrictions of HSR-JR605 robot

part of programming code

................................

MOVES ROBOT P18{205.1112,-263.9156,320.8333,-90.0000,30.0000,140.6536}Vtran=100

MOVES ROBOT P19{202.8824,-262.1114,321.8750,-90.0000,30.0000,132.5908}

MOVES ROBOT P20{200.3213,-258.5029,323.9583,-90.0000,30.0000,107.1232}

MOVES ROBOT P21{200.0001,-256.6987,325.0000,-90.0000,30.0000,90.0053}

MOVES ROBOT P22{200.3212,-254.8945,326.0417,-90.0000,30.0000,72.8654}

MOVES ROBOT P23{201.2835,-253.0903,327.0833,-90.0000,30.0000,58.4061}

MOVES ROBOT P24{202.8822,-251.2861,328.1250,-90.0000,30.0000,47.4065}

MOVES ROBOT P25{205.1113,-249.4819,329.1667,-90.0000,30.0000,39.3476}

MOVES ROBOT P26{207.9605,-247.6776,330.2083,-90.0000,30.0000,33.4335}

MOVES ROBOT P27{211.4182,-245.8734,331.2500,-90.0000,30.0000,29.0082}

MOVES ROBOT P28{220.0963,-242.2650,333.3333,-90.0000,30.0000,22.9961}

………………

(2) Discrete programming points with equal arc length, and obtain the coordinates of the discrete points. At this time, the arc length is set as 10 interpolation cycles of 1 mm.

Note: Since the industrial robot has 6 joints, which is a large number, only the results of joint 1 are given here, and other joints are not listed.

(3) Using the Cartesian coordinates and pose information of the point, the joint coordinates of the point are obtained, and the curve in the arc length domain is obtained.

(4) Using the joint coordinates calculated in the previous step and the speed at the programming point, calculate the joint speed, acceleration and torque respectively, and obtain the corresponding curve.

(5) Based on every two programming points, compare the calculated value with the actual attribute limit of the joint, diagnose whether there is an out-of-limit point, and deal with different situations differently. With the speed, acceleration and torque images of joint 1 above, we can quickly locate the point that exceeds the limit.

(6) After completing the previous processing, output the programming code optimized for the speed.

Part of the programming code after speed optimization is

................................

MOVES ROBOT P18{205.1112,-263.9156,320.8333,-90.0000,30.0000,140.6536}Vtran=160

MOVES ROBOT P19{202.8824,-262.1114,321.8750,-90.0000,30.0000,132.5908}

MOVES ROBOT P157{201.2834,-260.3072,322.9167,-90.0000,30.0000,121.6003}Vtran=95.0

MOVES ROBOT P20{200.3213,-258.5029,323.9583,-90.0000,30.0000,107.1232}Vtran=32.60

MOVES ROBOT P21{200.0001,-256.6987,325.0000,-90.0000,30.0000,90.0053}

MOVES ROBOT P22{200.3212,-254.8945,326.0417,-90.0000,30.0000,72.8654}

MOVES ROBOT P23{201.2835,-253.0903,327.0833,-90.0000,30.0000,58.4061}

MOVES ROBOT P24{202.8822,-251.2861,328.1250,-90.0000,30.0000,47.4065}

MOVES ROBOT P25{205.1113,-249.4819,329.1667,-90.0000,30.0000,39.3476}

MOVES ROBOT P26{207.9605,-247.6776,330.2083,-90.0000,30.0000,33.4335}

MOVES ROBOT P27{211.4182,-245.8734,331.2500,-90.0000,30.0000,29.0082}Vtran=32.60

MOVES ROBOT P158{215.4692,-244.0692,332.2917,-90.0000,30.0000,25.6325}Vtran=96.5

MOVES ROBOT P28{220.0963,-242.2650,333.3333,-90.0000,30.0000,22.9961}Vtran=160

………………

Comparing the two codes, it can be found from the codes of P157 and P158 that the number of programming points after optimization has increased, and the programming speed has also changed. The output programming code is optimized for speed and satisfying the kinematics of the robot.

Those skilled in the art can easily understand that the above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, etc., All should be included within the protection scope of the present invention.

Claims (3)

1. A method for diagnosing and optimizing the programming track of an industrial robot is characterized by comprising the following steps:

(1) acquiring an original programming code of a motion track of the industrial robot, establishing an industrial robot model, and acquiring attribute parameters of the industrial robot;

(2) dispersing a motion track generated by an original programming code to form a line segment with equal arc length and obtain a series of discrete points, setting the discrete arc length as an integral multiple of an interpolation period length, and storing Cartesian coordinates P (x, y, z, A, B and C) of the discrete points, wherein x, y and z are coordinates of an origin of a tool coordinate system relative to a workpiece coordinate system, and A, B and C are postures of the tool coordinate system relative to the workpiece coordinate system;

(3) according to the Cartesian coordinates P (x, y, z, A, B and C) of the discrete points, the joint coordinates J (theta) of each discrete point are obtained by inversion₁,θ₂,θ₃,θ₄,θ₅,θ₆)，θ₁,θ₂,θ₃,θ₄,θ₅,θ₆The angles of the joints i of the industrial robot are 1,2 … 6;

(4) respectively calculating the joint speed, the acceleration and the moment at each discrete point according to the joint coordinates and the programming speed at each discrete point;

(5) according to the joint speed, the acceleration and the moment at each discrete point, comparing the speed limit, the acceleration limit and the moment limit of each joint of the industrial robot respectively, diagnosing, and optimizing the programming speed of the region which cannot reach the programming speed;

(6) outputting the programming code with optimized speed, wherein the programming code increases programming points and optimizes the programming speed compared with the original programming code;

wherein, the specific process of comparison and diagnosis in the step (5) is as follows:

taking every two programming points of a motion track generated by original programming codes as a reference, and if all discrete points between the two programming points do not exceed the speed limit, the acceleration limit and the moment limit of each joint, the programming codes are unchanged;

if there are points between these two programmed points that exceed the velocity limit, acceleration limit, and moment limit of each joint, then the following programmed velocity optimization is performed: inserting a new programming point between the two programming points, segmenting the motion track between the two programming points, the new programming point coinciding with a discrete point just beyond the speed limit, acceleration limit and moment limit of each joint, and setting the minimum value of the maximum linear velocity allowed for each segment as the programming speed of the segment.

2. A method for programmed trajectory diagnosis and speed optimization for an industrial robot according to claim 1, characterized in that the programming speed is increased to a suitable value for programming points where no practical limit is exceeded and where an increase in speed is allowed.

3. The method of claim 1, wherein the property parameters include DH parameters, workpiece coordinate system, tool coordinate system, velocity limits, acceleration limits, and moment limits of each joint of the industrial robot.

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