Method and apparatus for monitoring the operation of a wafer handling robot

• US 20040073336A1
• Filed: 10/11/2002
• Published: 04/15/2004
• Est. Priority Date: 10/11/2002
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Huang, Kuo-Liang, Kuo, Enzo, Lin, Yuan-Chich, Chen, Patrick, Liu, Chun-Hung, Lai, Chih-Yi
• Granted Patent: US 6,871,115 B2
• Time in Patent Office: Days
• US Class Current: 700/245
• CPC Class Codes: B25J 9/1674 characterised by safety, monitoring, diagnostic
• CPC Class Codes: G05B 2219/34454 Check functioning controller, cpu or program
• CPC Class Codes: G05B 2219/42332 Detect failure of servo controller

Abstract

The integrity of control signals used to control a wafer handling robot is monitored by a monitor connected to various points of the robotic control system. The monitor includes a memory for storing data sets representing correct, reference characteristics of the control signals. The monitor samples control signals at various points in the control system and compares these sampled signals with the stored reference characteristics in order to determine whether a signal disparity exists. If a disparity exists, the monitor generates an error.

Claims

1. A method of monitoring the operation of a robot used to transport wafers in a semiconductor manufacturing operation, comprising the steps of:

(A) sensing control signals sent to said robot by a controller;

(B) comparing characteristics of the control signals sensed in step (A) with a set of reference characteristics representing correct commands to said robot; and

,

(C) issuing an error signal based on the comparison performed in step (B).

2. The method of claim 1, wherein step (A) includes detecting said signals during transmission thereof from a motor controller to a motor drive used to drive said robot.

3. The method of claim 2, wherein step (A) includes detecting said signals during transmission thereof from said motor driver to a motor used to drive said robot.

4. The method of claim 3, including the steps of:

(D) sensing a feedback position signals during transmission thereof from said robot to said controller,

(E) comparing characteristics of the feedback signals sensed in step (D) with a set of reference characteristics, and

(F) issuing an error signal if the comparison performed in step (E) indicates that the characteristics of the signals sensed in step (D) do not properly match said reference characteristics.

5. The method of claim 4, wherein step (D) is performed by sensing said feedback signals both before said signal passes through an electrical connector connecting said controller with said robot, and after said feedback signals passes through said connector.

6. The method of claim 1, wherein steps (A) through (C) are performed for each of three motor drives respectively controlling the movement of said robot about three axes.

7. The method of claim 1, wherein step (A) includes collecting first and second samples of said control signals by intercepting said control signals respectively before and after said controls signals pass through an electrical connector connecting said controller with said robot.

8. A method of monitoring the operation of a robot used to transport wafers in a semiconductor manufacturing operation, wherein said robot is of the type including a robot mechanism and a controller connected to the robot mechanism by an electrical connector, comprising the steps of:

(A) sampling control signals transmitted from said controller to said robot mechanism by intercepting said control signals during the transmission thereof,

(B) comparing the control signals sampled in step (A) with a first set of reference data related to correct commands to said robot;

(C) sampling feedback position signals transmitted from said robot mechanism to said controller by intercepting said feedback signals during transmission thereof,

(D) comparing the feedback signals sampled in step (C) with a second set of data related to correct feedback signals; and

(E) issuing an error signal if either the comparison performed in step (B) indicates that the signals sensed in step (A) do not properly match said first set of data, or the signals sampled in step (C) do not properly match said second set of data.

9. The method of claim 8, wherein step (A) is performed by:

sampling said control signals both before and after said control signals pass through said electrical connector, and

sampling said feedback signals both before and after said feedback signals pass through said electrical connector.

10. The method of claim 8, wherein steps (A) through (D) are performed for each of three motor drives respectively controlling the motion of said robot mechanism about three axes.

11. Apparatus for monitoring the operation of a robot used to transport wafers in a semiconductor manufacturing operation, wherein said robot includes a robotic mechanism driven by a motor and having an encoder for producing a feedback position signals, a controller including a motor controller and a motor drive for controlling the operation of said mechanism, and a set of electrical connections coupling said controller with said mechanism, comprising:

a monitor for sampling command signals issued by said controller and feedback signals generated by said encoder, for comparing said sampled signals with a set of reference data, and for issuing a error signal based on the signal comparison; and

,

a set of electrical connections between said monitor and said controller and said mechanism, said connections intercepting said command signals and said feedback signals and delivering said command signals and said feedback signals to said monitor.

12. The apparatus of claim 11, wherein said monitor includes a processor for comparing said sampled signals with said reference data, and including a memory for storing said reference data,.

13. The apparatus of claim 12, wherein said monitor includes a data acquisition circuit for acquiring and collecting the sampled signals.

14. The apparatus of claim 13, including an annunciator for annunciating said error signal.

15. The apparatus of claim 11, wherein said electrical connections include a first connection for intercepting command signals transmitted from said motor controller to said motor drive.

16. The apparatus of claim 15, wherein said electrical connections include a second connection for intercepting signals transmitted from said motor drive to said motor.

17. The apparatus of claim 16, wherein said electrical connections include a third connection for intercepting feedback signals transmitted from said encoder to controller.

18. The apparatus of claim 17, wherein said robot further includes a connector coupling said robotic mechanism with said controller, said third connection includes a first portion for intercepting signals passing from said encoder to said to said connector, and a second portion for intercepting signals passing from said connector to said controller.

19. The apparatus of claim 11, wherein said electrical connections include a connection for intercepting signals transmitted from said motor drive to said motor.

20. The apparatus of claim 11, wherein said electrical connections include a connection for intercepting feedback signals transmitted from said encoder to controller.