MECHANICAL ARM POSITIONING METHOD AND SYSTEM ADOPTING THE SAME

• US 20180111271A1
• Filed: 07/10/2017
• Published: 04/26/2018
• Est. Priority Date: 10/21/2016
• Status: Abandoned Application

• Current Assignee: Pegatron Corporation
• Original Assignee: Pegatron Corporation
• Inventors: HWANG, Hsiang-Tin, WANG, Jen-Hui, WANG, Chiung-Hung, CHENG, Jen-Wei
• Application Number:
  US15/644,834
• Publication Number:
  US 20180111271A1
• Time in Patent Office: Days
• CPC Class Codes: B25J 9/1692 Calibration of manipulator
• CPC Class Codes: B25J 9/1697 Vision controlled systems
• CPC Class Codes: G05B 2219/39045 Camera on end effector detects reference pattern
• CPC Class Codes: G05B 2219/39046 Compare image of plate on robot with reference, move till coincidence, camera
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/1417 2D bar codes
• CPC Class Codes: G06T 2207/30204 Marker
• CPC Class Codes: G06T 7/60 Analysis of geometric attributes
• CPC Class Codes: G06T 7/66 of image moments or centre of gravity
• CPC Class Codes: G06T 7/74 involving reference images or patches
• CPC Class Codes: G06V 10/245 by locating a pattern; Special marks for positioning
• CPC Class Codes: H04N 23/57 Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices

Abstract

A mechanical arm positioning method configured to position a mechanical arm at a fixed point. The method includes capturing a positioning pattern through an image-capturing module disposed on mechanical arm to generate an image with a positioning image, the positioning image corresponding to positioning pattern. Subsequently, whether a center of positioning image is located at a center of the image is determined. If not, a position of mechanical arm is adjusted in parallel with a plane where the positioning pattern is located until the center of positioning image is located at the center of the image. Subsequently, whether an area of positioning image is substantially equal to a predetermined area is determined. If not, a distance between mechanical arm and positioning pattern is adjusted perpendicular to plane where the positioning pattern is located until the area of positioning image is substantially equal to predetermined area.

Claims

1. A mechanical arm positioning method configured to position a mechanical arm at a fixed point, the mechanical arm positioning method comprising:

capturing a positioning pattern through utilizing an image-capturing module disposed at the mechanical arm to obtain a comparison image with a positioning image, wherein the positioning image corresponds to the positioning pattern;

determining whether a center of the positioning image is located at a center of the comparison image;

adjusting a position of the mechanical arm in parallel with a plane where the positioning pattern is located such that the center of the positioning image to be located at the center of the comparison image if the center of the positioning image is not located at the center of the comparison image;

determining whether an area of the positioning image is substantially equal to a predetermined area; and

adjusting a position of the mechanical arm perpendicular to the plane where the positioning pattern is located to change a distance between the image-capturing module and the positioning pattern if the area of the positioning image is not equal to the predetermined area such that the area of the positioning image to be substantially equal to the predetermined area.

2. The mechanical arm positioning method of claim 1, further comprising:

determining whether an acute angle between an edge of the positioning image and an edge of the comparison image is substantially equal to a predetermined angle; and

rotating the mechanical arm in parallel with the plane where the positioning pattern is located if the acute angle is not equal to the predetermined angle such that the acute angle to be substantially equal to the predetermined angle, wherein the predetermined angle is generated by using the image-capturing module to capture the positioning pattern when the mechanical arm is located at the fixed point.

3. The mechanical arm positioning method of claim 1, wherein the determining whether the area of the positioning image is substantially equal to the predetermined area comprises:

determining a magnitude relationship between the area of the positioning image and the predetermined area;

adjusting the mechanical arm to move away from the positioning pattern along a direction perpendicular to the plane where the positioning pattern is located if the area of the positioning image is larger than the predetermined area; and

adjusting the mechanical arm to move closer to the positioning pattern along the direction perpendicular to the plane where the positioning pattern is located if the area of the positioning image is smaller than the predetermined area.

4. The mechanical arm positioning method of claim 1, further comprising:

utilizing the image-capturing module to capture the positioning pattern so as to generate a standard image with a standard positioning image when the mechanical arm is located at the fixed point; and

generating the predetermined area based on an area of the standard positioning image.

5. The mechanical arm positioning method of claim 1, wherein the mechanical arm further comprises a three-axis gravitational acceleration measurement module having a three-axis gravitational acceleration value, wherein the three-axis gravitational acceleration value corresponds to degrees of rotation of the mechanical arm, the mechanical arm positioning method further comprises:

determining whether the three-axis gravitational acceleration value is substantially equal to a predetermined three-axis gravitational acceleration value; and

rotating the mechanical arm such that the three-axis gravitational acceleration value of the three-axis gravitational acceleration measurement module to be substantially equal to the predetermined three-axis gravitational acceleration value if the three-axis gravitational acceleration value is not equal to the predetermined three-axis gravitational acceleration value.

6. The mechanical arm positioning method of claim 5, further comprising:

capturing the three-axis gravitational acceleration value of the three-axis gravitational acceleration measurement module to generate a standard gravity sensing data when the mechanical arm is located at the fixed point; and

generating the predetermined three-axis gravitational acceleration value based on values of the standard gravity sensing data.

7. A mechanical arm system comprising:

a mechanical arm comprising a movable end and at least one driving member, and the at least one driving member being configured to move the movable end to a fixed point;

an image-capturing module fixed to the movable end, the image-capturing module configured to capture a positioning pattern at a moving point so as to generate a comparison image with a positioning image, wherein the positioning image corresponds to the positioning pattern; and

a computing device configured to determine whether a center of the positioning image is located at a center of the comparison image, if not, the driving member being driven to adjust a position of the movable end in parallel with a plane where the positioning pattern is located such that the center of the positioning image to be located at the center of the comparison image, and determine whether an area of the positioning image is substantially equal to a predetermined area, if not, the driving member being driven to adjust a position of the movable end along a direction perpendicular to the plane where the positioning pattern is located to change a distance between the image-capturing module and the positioning pattern so as to allow the area of the positioning image to be substantially equal to the predetermined area.

8. The mechanical arm system of claim 7, wherein the computing device is further configured to determine a magnitude relationship between the area of the positioning image and the predetermined area, the driving member is driven such that the movable end to move away from the positioning pattern along the direction perpendicular to the plane where the positioning pattern is located if the area of the positioning image is larger than the predetermined area, the driving member is driven such that the movable end to move closer to the positioning pattern along the direction perpendicular to the plane where the positioning pattern is located if the area of the positioning image is smaller than the predetermined area.

9. The mechanical arm system of claim 7, wherein the image-capturing module is further configured to utilize the image-capturing module to capture the positioning pattern so as to generate a standard image with a standard positioning image when the movable end of the mechanical arm is located at the fixed point, and generate the predetermined area based on the standard positioning image.

10. The mechanical arm system of claim 7, wherein the driving member is further configured to rotate the movable end, wherein the computing device further determines whether an acute angle between an edge of the positioning image and an edge of the comparison image is substantially equal to a predetermined angle, if not, the driving member is driven to rotate the movable end in parallel with the plane where the positioning pattern is located such that the acute angle between the edge of positioning image and the edge of the comparison image to be substantially equal to the predetermined angle.

11. The mechanical arm system of claim 7, wherein the driving member is further configured to rotate the movable end, wherein the mechanical arm system further comprises a three-axis gravitational acceleration measurement module disposed on the mechanical arm, the three-axis gravitational acceleration measurement module is configured to measure a three-axis gravitational acceleration value corresponding to degrees of rotation of the movable end of the mechanical arm, the computing device is further configured to determine whether the three-axis gravitational acceleration value is substantially equal to a predetermined three-axis gravitational acceleration value, if not, the driving member is driven to rotate the movable end so as to allow the three-axis gravitational acceleration value of the three-axis gravitational acceleration measurement module to be substantially equal to the predetermined three-axis gravitational acceleration value.

12. The mechanical arm system of claim 11, wherein the three-axis gravitational acceleration measurement module is further configured to capture the three-axis gravitational acceleration value of the three-axis gravitational acceleration measurement module to generate a standard gravity sensing data when the movable end of the mechanical arm is located at the fixed point, and generate the predetermined three-axis gravitational acceleration value based on the standard gravity sensing data.