Patent attributes
A first robot arm places a calibration object into a load lock that separates a factory interface from a transfer chamber using a first taught position. A second robot arm retrieves the calibration object from the load lock using a second taught position. A controller determines, using a sensor, a first offset amount between a calibration object center of the calibration object and a pocket center of the second robot arm. The controller determines a characteristic error value that represents a misalignment between the first taught position of the first robot arm and the second taught position of the second robot arm based on the first offset amount. The first robot arm or the second robot arm uses the first characteristic error value to compensate for the misalignment for objects transferred between the first robot arm and the second robot arm via the load lock.