End effector bump detector

Abstract

A system and method is described for detecting abnormal contacts and misalignment of end effector of a robot arm during robotic arm operation. A contact shock transients sensing unit detects signals on the robot arm and generates alarms, identifies the location of the contact shock transients in the robot arm operation, and controls robot arm operation to prevent further damage to the robot arm and articles handled by the robot arm.

What is claimed is: 
     
         1 . An apparatus comprising:
 a contact shock transients sensing unit coupled to a robot arm and configured to:
 detect contact shock transients on the robot arm, and 
 generate a signal corresponding to contact shock transients; and 
   a control unit coupled to the contact shock transients sensing unit, the control unit is configured to:
 measure an amount of the signal generated, 
 determine whether the amount of the signal exceeds one or more predetermined thresholds, and 
 execute one or more predetermined operations based on the determination. 
   
     
     
         2 . The apparatus of  claim 1 , wherein the contact shock transients sensing unit is coupled to the control unit via one or more of:
 a wireless communication, and   a wireline communication.   
     
     
         3 . The apparatus of  claim 1 , wherein the contact shock transients sensing unit is further configured to detect contact shock transients generated by one or more of:
 a contact force,   a pressure,   an acceleration of the robot arm, and   a strain.   
     
     
         4 . The apparatus of  claim 1 , wherein the contact shock transients sensing unit comprises a piezo electric sensor. 
     
     
         5 . The apparatus of  claim 4 , wherein
 the piezo electric sensor generates electrical signals corresponding to contact shock transients,   the piezo electric sensor is mounted on a diaphragm, and   the diaphragm is coupled to the robot arm.   
     
     
         6 . The apparatus of  claim 1 , wherein
 the contact shock transients sensing unit is coupled to an end effector of the robot arm, and   the end effector of the robot arm is configured to carry a semiconductor wafer.   
     
     
         7 . The apparatus of  claim 6 , wherein the predetermined operation include one or more of:
 identify a location of the robot arm in a manufacturing process where the amount of the signal exceeds the one or more predetermined thresholds;   generate an alarm if the amount of signal exceeds a first predetermined threshold; and   terminate operation of the robot arm in the manufacturing process if the amount of signal exceeds a second predetermined threshold.   
     
     
         8 . A method comprising:
 detecting contact shock transients generated by a robot arm;   generating a signal corresponding to contact shock transients;   measuring an amount of the signal;   determining whether the amount of the signal exceeds one or more predetermined thresholds; and   executing one or more predetermined operations based on the determination.   
     
     
         9 . The method of  claim 8 , wherein the predetermined operation include one or more of:
 identifying a location of the robot arm in a manufacturing process where the amount of signal exceeds one or more predetermined thresholds,   generating an alarm if the amount of signal exceeds a first predetermined threshold, and   terminating operation of the robot arm if the amount of signal exceeds a second predetermined threshold.   
     
     
         10 . The method of  claim 8 , wherein
 the contact shock transients are detected by a contact shock transients sensing unit coupled to the robot arm at an end effector of the robot arm, and   the end effector is configured to carry a semiconductor wafer.   
     
     
         11 . The method of  claim 10 , wherein the contact shock transients sensing unit comprises a piezo electric sensor. 
     
     
         12 . The method of  claim 11 , wherein
 the piezo electric sensor generates electrical signals corresponding to contact shock transients,   the piezo electric sensor is mounted on a diaphragm, and   the diaphragm is coupled to the robot arm.   
     
     
         13 . The method of  claim 11 , wherein the contact shock transients of the robot arm are generated by one or more of:
 a contact force,   a pressure,   an acceleration of the robot arm, and   a strain.   
     
     
         14 . A system comprising:
 a robot control unit, configured to control movement of a robot arm;   a contact shock transients sensing unit coupled to the robot arm and configured to:
 detect contact shock transients generated on the robot arm, and 
 generate a signal corresponding to the contact shock transients; and 
   a processing unit coupled to the contact shock transients sensing unit, the processing unit is configured to:
 measure an amount of the signal generated, 
 determine whether the amount of the signal exceeds one or more predetermined thresholds, and 
 execute one or more predetermined operations based on the determination. 
   
     
     
         15 . The system of  claim 14 , wherein
 the processing unit is coupled to contact shock transients sensing unit via one or more of:
 a wireless communication, and 
 a wireline communication. 
   
     
     
         16 . The system of  claim 14 , wherein the contact shock transients sensing unit is further configured to detect contact shock transients by sensing one or more of:
 a contact force,   a pressure,   an acceleration of the robot arm, and   a strain.   
     
     
         17 . The system of  claim 14 , wherein
 the contact shock transients sensing unit comprises a piezo electric sensor,   the piezo electric sensor generates electrical signals corresponding to contact shock transients,   the piezo electric sensor is mounted on a diaphragm, and   the diaphragm is coupled to the robot arm.   
     
     
         18 . The system of  claim 14 , wherein
 the contact shock transients sensing unit is coupled to the robot arm at an end effector of the robot arm, and   the robot arm is configured to carry a semiconductor wafer at the end effector of the robot arm.   
     
     
         19 . The system of  claim 14 , wherein the predetermined operation include one or more of:
 identify a location of the robot arm in the manufacturing process where the amount of the signal exceeds one or more predetermined thresholds;   generate an alarm if the amount of the signal exceeds a first predetermined threshold; and   terminate operation of the robot arm if the amount of the signal exceeds a second predetermined threshold.