阅读说明：本技术 校正函数生成装置、机器人控制系统及机器人系统 (Correction function generation device, robot control system, and robot system ) 是由 儿岛谅 于 2018-02-26 设计创作，主要内容包括：本发明不增加成为位置测量的对象的点,就能够高精度地控制机器人臂的指尖的位置。一种校正函数生成装置(100a),其生成为了对具有关节的机器人臂的指尖的位置进行控制所使用的校正函数,该校正函数生成装置(100a)具有：信息取得部(110a),其取得在机器人臂的规定位置处测量出的温度信息、测量出温度信息的时刻的关节的角度、及对测量出温度信息的时刻的指尖的位置进行测量而得到的测量位置；指尖位置推定部(120a),其基于取得的关节的角度,对取得了温度信息的时刻的指尖的位置进行推定而求出推定位置；以及校正函数决定部(130a),其基于对测量位置和推定位置进行比较的结果,决定将温度信息设为变量的函数即所述校正函数。(The invention can control the position of the fingertip of a robot arm with high precision without increasing the point of the position measurement object. A correction function generation device (100a) that generates a correction function used for controlling a position of a fingertip of a robot arm having a joint, the correction function generation device (100a) having: an information acquisition unit (110a) that acquires temperature information measured at a predetermined position of the robot arm, an angle of a joint at the time when the temperature information was measured, and a measurement position at which the position of a fingertip at the time when the temperature information was measured; a fingertip position estimation unit (120a) that estimates the position of the fingertip at the time when the temperature information is acquired, based on the acquired joint angle, and that obtains an estimated position; and a correction function determination unit (130a) that determines the correction function, which is a function having temperature information as a variable, based on the result of comparing the measured position and the estimated position.)

1. A correction function generation device that generates a correction function used for controlling a position of a fingertip of a robot arm having a joint,

the correction function generation device includes:

an information acquisition unit that acquires temperature information measured at a predetermined position of the robot arm, an angle of the joint at a time when the temperature information is measured, and a measurement position at which a position of the fingertip at the time when the temperature information is measured;

a fingertip position estimating unit that estimates a position of the fingertip at a time when the temperature information is acquired, based on an angle of the joint, to obtain an estimated position; and

and a correction function determination unit that determines the correction function, which is a function having the temperature information as a variable, based on a result of comparing the measured position and the estimated position.

2. The correction function generation apparatus according to claim 1,

the temperature information, the angle of the joint, and the measurement position are acquired at a plurality of times,

the fingertip position estimating unit obtains the estimated positions at the plurality of times,

the correction function determination unit determines the correction function based on a result of comparing the measured position and the estimated position at each of the plurality of times.

3. The correction function generation apparatus according to claim 1 or 2,

the measurement position is acquired as a displacement from a predetermined reference position.

4. The correction function generation apparatus according to any one of claims 1 to 3,

the correction function determining section determines, based on the correction function,

outputting the correction function corresponding to the estimated position when a result of comparing the measured position and the estimated position satisfies a predetermined condition,

when the result of comparing the measured position and the estimated position does not satisfy the predetermined condition, a request is made to the fingertip position estimating unit so that the position of the fingertip is estimated again.

5. The correction function generation apparatus according to claim 4,

the fingertip position estimating unit includes:

a candidate function generating unit that generates a candidate function that is a function having the temperature information as a variable as a candidate of the correction function; and

and a fingertip position calculation unit that obtains the estimated position based on the temperature information, the angle of the joint, and the candidate function.

6. The correction function generation apparatus according to claim 5,

the correction function determination unit outputs the candidate function used for obtaining the estimated position as the correction function when the result of comparing the measured position and the estimated position satisfies the predetermined condition.

7. The correction function generation apparatus according to claim 5 or 6,

the candidate function is a function that sets the temperature of the surroundings of the robot arm as a variable.

8. The correction function generation apparatus according to any one of claims 5 to 7,

the candidate function is a function for correcting the length of each of a plurality of portions obtained by dividing the robot arm using the temperature information as a variable,

the fingertip position calculation unit corrects the lengths of the plurality of portions based on the temperature information and the candidate function, and obtains the estimated position based on the corrected lengths of the plurality of portions and the angle of the joint.

9. The correction function generation apparatus according to claim 8,

the plurality of sites each exist in a range that does not span the joint.

10. The correction function generation apparatus according to claim 4,

the fingertip position estimating unit includes:

a length estimation unit configured to estimate a length of each of a plurality of portions obtained by dividing the robot arm; and

and a fingertip position calculation unit that obtains the estimated position based on the angle of the joint and the estimated length of each of the plurality of portions.

11. The correction function generation apparatus according to claim 10,

the correction function determination unit generates the correction function based on the respective lengths of the plurality of portions used to obtain the estimated position and the temperature information when the result of comparing the measured position and the estimated position satisfies the predetermined condition.

12. A robot control system having the correction function generation apparatus according to any one of claims 8 to 11 and a robot control apparatus,

in the robot control system according to the present invention,

the robot control device includes:

a correction function acquisition unit that acquires the correction function from the correction function generation device;

a link length correction unit that corrects the lengths of the plurality of portions using the correction function and the temperature information; and

and a command value generation unit that generates an operation command value for controlling the robot arm so that the fingertip reaches a target position, based on the corrected lengths of the plurality of portions.

13. The robot control system of claim 12, wherein,

the robot control device includes:

a correction function storage unit that stores a plurality of correction functions generated by the correction function generation device under different operating conditions of the robot arm; and

a correction function selection unit that selects 1 of the plurality of correction functions stored by the correction function storage unit based on the operating condition of the robot arm,

the link length correction unit corrects the lengths of the plurality of portions using the correction function selected by the correction function selection unit and the temperature information.

14. The robot control system according to claim 12 or 13, wherein,

the instruction value generation unit includes:

a1 st angle calculation unit that calculates, as a1 st target angle, an angle of the joint for allowing the fingertip to reach the target position, based on the length of each of the reference portions;

a2 nd angle calculation unit that calculates, as a2 nd target angle, an angle of the joint for causing the fingertip to reach the target position, based on the corrected lengths of the respective portions;

a joint angle evaluation unit that compares the 2 nd target angle with a preset limit condition to generate a correction coefficient; and

a3 rd angle calculation unit that calculates a3 rd target angle based on the 1 st target angle, the 2 nd target angle, and the correction coefficient,

generating the motion command value based on the 3 rd target angle.

15. A robotic system having the robotic control system of any one of claims 12-14, and the robotic arm controlled by the robotic control system.

Technical Field

The present invention relates to a correction function generation device that generates a correction function used for controlling a position of a fingertip of a robot arm having a joint, and a robot control system and a robot system having the correction function generation device.

Background

In factories and the like, robot arms are used for the purpose of performing repetitive work with high accuracy. However, the temperature of the robot arm may change due to heat generation of a motor for driving the robot arm and an influence of a change in ambient temperature. The positions of the fingertips of the robot arm change due to the temperature change of the robot arm, whereby the robot arm thermally expands or contracts. As a result, the robot control system cannot control the position of the fingertip of the robot arm with high accuracy. That is, the accuracy of positioning the fingertip is degraded. For example, in a repeated work for approaching a predetermined position, the robot arm gradually extends as the temperature of the robot arm rises. As a result, the position of the fingertip gradually changes, and the work accuracy is significantly impaired. In order to solve this problem, for example, patent document 1 proposes a method of measuring the length between desired control points, and obtaining a change in the length from a reference temperature, thereby obtaining a correction coefficient for correcting the length between the desired control points.

Patent document 1: japanese laid-open patent publication (JP 2015-141583)

Disclosure of Invention

In the method proposed in patent document 1, it is necessary to measure a change in length between control points of the robot arm corresponding to a temperature change with high accuracy. The length between the control points can be determined by measuring the position of each control point. However, if the number of control points increases, the number of points to be measured also increases. As a result, the measurement time increases, and the measuring machine becomes complicated.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a correction function generation device capable of generating a correction function for accurately estimating the position of a fingertip of a robot arm without increasing the number of points to be subjected to position measurement. Another object is to provide a robot control system and a robot system having the correction function generation device.

A correction function generation device according to the present invention generates a correction function used for controlling a position of a fingertip of a robot arm having a joint, the correction function generation device including: an information acquisition unit that acquires temperature information measured at a predetermined position of the robot arm, an angle of a joint at a time when the temperature information is measured, and a measurement position at which a position of a fingertip at the time when the temperature information is measured; a fingertip position estimating unit that estimates a position of a fingertip at a time when the temperature information is acquired, based on an angle of the joint, and obtains an estimated position; and a correction function determination unit that determines a correction function that is a function having temperature information as a variable, based on a result of comparing the measured position and the estimated position.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the correction function generation device of the present invention, it is possible to generate a correction function for controlling the position of the fingertip of the robot arm with high accuracy without increasing the number of points to be subjected to position measurement. Further, according to the robot control system and the robot system of the present invention, the position of the fingertip of the robot arm can be controlled with high accuracy without increasing the number of points to be subjected to position measurement.

Drawings

Fig. 1 is a diagram showing an example of the configuration of a robot system and a robot control system including a correction function generation device according to embodiment 1 of the present invention.

Fig. 2 is a diagram showing an example of the configuration of a robot arm according to embodiment 1 of the present invention.

Fig. 3 is a diagram showing an example of a hardware configuration for realizing a robot control system including the correction function generation device according to embodiment 1 of the present invention.

Fig. 4 is a diagram showing an example of an operation flow of a robot control system including the correction function generation device according to embodiment 1 of the present invention.

Fig. 5 is a diagram showing an example of the configuration of the correction function generation device according to embodiment 1 of the present invention.

Fig. 6 is a diagram showing an example of the operation flow of the correction function generation device according to embodiment 1 of the present invention.

Fig. 7 is a diagram showing an example of the operation flow of the fingertip position estimating unit and the correction function determining unit in the correction function generating device according to embodiment 1 of the present invention.

Fig. 8 is a diagram showing an example of the configuration of a robot controller according to embodiment 1 of the present invention.

Fig. 9 is a diagram showing an example of an operation flow of the robot controller according to embodiment 1 of the present invention.

Fig. 10 is a diagram showing another example of the operation flow of the robot control system including the correction function generation device according to embodiment 1 of the present invention.

Fig. 11 is a diagram showing an example of the configuration of a robot system and a robot control system including the correction function generation device according to embodiment 2 of the present invention.

Fig. 12 is a diagram showing an example of an operation flow of a robot control system including the correction function generation device according to embodiment 2 of the present invention.

Fig. 13 is a diagram showing an example of the configuration of the correction function generation device according to embodiment 2 of the present invention.

Fig. 14 is a diagram showing an example of the operation flow of the correction function generation device according to embodiment 2 of the present invention.

Fig. 15 is a diagram showing an example of the operation flow of the fingertip position estimating unit and the correction function determining unit in the correction function generating device according to embodiment 2 of the present invention.

Fig. 16 is a diagram showing an example of the configuration of a robot system and a robot control system including the correction function generation device according to embodiment 3 of the present invention.

Fig. 17 is a diagram showing an example of the configuration of the correction function generation device according to embodiment 3 of the present invention.

Fig. 18 is a diagram showing an example of the configuration of a robot controller according to embodiment 3 of the present invention.

Fig. 19 is a diagram showing an example of the configuration of a robot system according to embodiment 4 of the present invention.

Fig. 20 is a diagram showing an example of the configuration of a robot arm in the robot system according to embodiment 4 of the present invention.

Fig. 21 is a diagram showing an example of the configuration of a robot system according to embodiment 5 of the present invention.

Fig. 22 is a diagram showing an example of the configuration of the correction function generation device according to embodiment 5 of the present invention.

Fig. 23 is a diagram showing an example of the operation flow of the correction function generation device according to embodiment 5 of the present invention.

Fig. 24 is a diagram showing an example of the configuration of a correction function generation unit in the correction function generation device according to embodiment 5 of the present invention.

Fig. 25 is a diagram showing an example of the operation flow of the correction function generation unit in the correction function generation device according to embodiment 5 of the present invention.

Fig. 26 is a diagram showing an example of the configuration of a robot system according to embodiment 6 of the present invention.

Fig. 27 is a diagram showing an example of the configuration of a robot controller according to embodiment 6 of the present invention.

Fig. 28 is a diagram showing an example of an operation flow of the robot control system according to embodiment 6 of the present invention.

Fig. 29 is a diagram showing an example of the configuration of a robot system according to embodiment 7 of the present invention.

Fig. 30 is a diagram showing an example of the configuration of a robot controller according to embodiment 7 of the present invention.

Fig. 31 is a diagram showing an example of the configuration of a command value generation unit in the robot control device according to embodiment 7 of the present invention.

Detailed Description