Robot programming method and apparatus with both vision and force

• US 20080027580A1
• Filed: 07/28/2006
• Published: 01/31/2008
• Est. Priority Date: 07/28/2006
• Status: Abandoned Application

• Current Assignee: Heping Chen, Hui Zhang, Jianjun Wang
• Original Assignee: Heping Chen, Hui Zhang, Jianjun Wang
• Inventors: Chen, Heping, Zhang, Hui, Wang, Jianjun
• Application Number:
  US11/495,016
• Publication Number:
  US 20080027580A1
• Time in Patent Office: Days
• US Class Current: 700/245
• CPC Class Codes: B25J 9/1633 compliant, force, torque control, e.g. combined with position control
• CPC Class Codes: B25J 9/1664 characterised by motion, path, trajectory planning
• CPC Class Codes: B25J 9/1694 characterised by use of sensors other than normal servo-feedback from position, speed or acceleration sensors, perception control, multi-sensor controlled systems, sensor fusion
• CPC Class Codes: G05B 2219/39391 Visual servoing, track end effector with camera image feedback
• CPC Class Codes: G05B 2219/40571 Camera, vision combined with force sensor

Abstract

Both vision and force control are used to program a robot so that a tool having a tip can follow a desired path visibly marked on a workpiece when the tool is to perform work on the workpiece. There is a force sensor, a camera positioned to view the visibly marked path and a computing device. When the tool tip is in controlled contact with an area of the workpiece that includes the desired path, the camera and the force sensor each provide information to the computing device. The information is used to develop a program to move the robot to cause the tool tip to follow the desired path when the tool is to perform work on the workpiece. The tool can move in relation to the workpiece and the camera is mounted on the robot or the workpiece moves in relation to the stationary camera and tool.

Claims

1. A system for programming a robot so that a tool having a tip can follow a desired path visibly marked on a workpiece when said tool is to perform work on said workpiece comprising:

a force sensor;

a camera oriented to view said visibly marked desired path; and

a computing device associated with said robot;

said force sensor and said camera each providing information to said computing device when said tool tip is in controlled contact with an area of said workpiece that includes said desired path, said computing device using said information to develop a program for motion of said robot that causes said tool tip to follow said desired path when said tool is to perform work on said workpiece.

2. The system of claim 1 wherein said robot holds said tool in a manner such that said tool is caused to move in relation to said workpiece when said tool is to perform work on said workpiece and said camera is mounted on said robot in a manner to move with said tool.

3. The system of claim 1 wherein said tool and said camera are stationary and said robot holds said workpiece in a manner such that said workpiece is caused to move in relation to said tool when said tool is to perform work on said workpiece.

4. The system of claim 1 wherein said force sensor is mounted on said robot.

5. A method for programming a robot so that a tool having a tip can follow a desired path visibly marked on a workpiece when said tool is to perform work on said workpiece comprising:

using an image of a point on said desired path when said tool tip is on said desired path and one or more other points related to said point on said desired path when said tool tip is in controlled contact with an area on said workpiece that includes said desired path to determine a predetermined number of degrees of freedom information for said point on said desired path;

repeating said step above to determine said predetermined number of degrees of freedom information for one or more other points on said desired path; and

developing from said determined predetermined number of degrees of freedom information for said point on said desired path and each of said one or more other points on said desired path a program for motion of said robot that allows said tool tip to follow said desired path when said tool is to perform work on said workpiece.

6. The method of claim 5 wherein said one or more other points related to said point on said desired path are obtained by causing said tool tip to follow a first path which is an offset of said desired path on one side of said desired path and a second path which is an offset of said desired path on another side of said desired path.

7. The method of claim 6 wherein said offset of each of said first and second paths is identical.

8. The method of claim 5 wherein said one or more other points related to said point on said desired path are obtained by causing said tool tip to follow a predetermined pattern that crosses said desired path from one side to another side of said desired path.

9. The method of claim 5 further comprising bringing said tool tip in said controlled contact with said workpiece.

10. A method for programming a robot so that a tool having a tip can follow a desired path visibly marked on a workpiece when said tool is to perform work on said workpiece comprising:

determining from an image of each of a plurality of points on said desired path when said tool tip is on said desired path and is in controlled contact with said workpiece the X, Y and Z locations of each of said plurality of points on said desired path and the roll angle of said tool with said desired path at each of said plurality of points;

using each of said plurality of points on said desired path and one or more other points related to each of said plurality of points on said desired path when said tool tip is in controlled contact with an area on said workpiece related to said desired path to determine the pitch and yaw angles of said tool with said desired path for each of said plurality of points on said desired path; and

developing from said X, Y and Z locations and said roll, pitch and yaw angles for each of plurality of points on said desired path a program for motion of said robot that allows said tool tip to follow said desired path when said tool is to perform work on said workpiece.

11. The method of claim 10 wherein said one or more other points related to said each of said plurality of points on said desired path are obtained by causing said tool tip to follow a first path which is an offset of said desired path on one side of said desired path and a second path which is an offset of said desired path on another side of said desired path.

12. The method of claim 11 wherein said offset of each of said first and second paths is identical.

13. The method of claim 10 wherein said one or more other points related to each of said one or more other points on said desired path are obtained by causing said tool tip to follow a predetermined pattern that cyclically crosses said desired path from one side to another side of said desired path.

14. A computer program product for programming a robot so that a tool having a tip can follow a desired path visibly marked on a workpiece when said tool is to perform work on said workpiece, comprising:

a computer-readable medium having instructions for causing a computer to execute a method comprising;

using an image of a point on said desired path when said tool tip is on said desired path and one or more other points related to said point on said desired path when said tool tip is in controlled contact with an area on said workpiece that includes said desired path to determine a predetermined number of degrees of freedom information for said point on said desired path;

repeating said step above to determine said predetermined number of degrees of freedom information for one or more other points on said desired path; and

developing from said determined predetermined number of degrees of freedom information for said point on said desired path and each of said one or more other points on said desired path a program for motion of said robot that allows said tool tip to follow said desired path when said tool is to perform work on said workpiece.

15. A computer program product for programming a robot so that a tool having a tip can follow a desired path visibly marked on a workpiece when said tool is to perform work on said workpiece, comprising:

a computer-readable medium having instructions for causing a computer to execute a method comprising;

determining from an image of each of a plurality of points on said desired path when said tool tip is on said desired path and is in controlled contact with said workpiece the X, Y and Z locations of each of said plurality of points on said desired path and the roll angle of said tool with said desired path at each of said plurality of points;

using each of said plurality of points on said desired path and one or more other points related to each of said plurality of points on said desired path when said tool tip is in controlled contact with an area on said workpiece related to said desired path to determine the pitch and yaw angles of said tool with said desired path for each of said plurality of points on said desired path; and

developing from said X, Y and Z locations and said roll, pitch and yaw angles for each of plurality of points on said desired path a program for motion of said robot that allows said tool tip to follow said desired path when said tool is to perform work on said workpiece.

16. A system for programming a robot so that a tool having a tip can follow a desired path visibly marked on a workpiece when said tool is to perform work on said workpiece, said system comprising:

a computing device having therein program code usable by said computing device, said program code comprising;

code configured to use an image of a point on said desired path when said tool tip is on said desired path and one or more other points related to said point on said desired path when said tool tip is in controlled contact with an area on said workpiece that includes said desired path to determine a predetermined number of degrees of freedom information for said point on said desired path;

code configured to repeat said step above to determine said predetermined number of degrees of freedom information for one or more other points on said desired path; and

code configured to develop from said determined predetermined number of degrees of freedom information for said point on said desired path and each of said one or more other points on said desired path a program for motion of said robot that allows said tool tip to follow said desired path when said tool is to perform work on said workpiece.

17. A system for programming a robot so that a tool having a tip can follow a desired path visibly marked on a workpiece when said tool is to perform work on said workpiece, said system comprising:

a computing device having therein program code usable by said computing device, said program code comprising;

code configured to determine from an image of each of a plurality of points on said desired path when said tool tip is on said desired path and is in controlled contact with said workpiece the X, Y and Z locations of each of said plurality of points on said desired path and the roll angle of said tool with said desired path at each of said plurality of points;

code configured to use each of said plurality of points on said desired path and one or more other points related to each of said plurality of points on said desired path when said tool tip is in controlled contact with an area on said workpiece related to said desired path to determine the pitch and yaw angles of said tool with said desired path for each of said plurality of points on said desired path; and

code configured to develop from said X, Y and Z locations and said roll, pitch and yaw angles for each of plurality of points on said desired path a program for motion of said robot that allows said tool tip to follow said desired path when said tool is to perform work on said workpiece.