Robot end-effector terminal control frame (TCF) calibration method and device

A method for calibrating a tool control frame (TCF) of a robot with respect to a known calibration reference frame (CRF), which CRF moves with and is associated with a robot link in rigid body relationship, said method comprising the steps of:

• a) attaching a sensory tooling assembly to a link of the robot in rigid body relationship, which link has a known positional and orientational relationship with respect to the CRF and which allows for feedback of positional and/or orientational information with respect to a sensory reference frame associated with the sensory tooling assembly;
• b) calibrating the sensory tooling assembly and any data output systems associated with the tooling assembly to enable sensor output in units capable of defining physical dimensions;
• c) identifying a calibration feature separate from the robot which is capable of being mapped by the sensory tooling assembly;
• d) causing relative movement of the calibration feature and sensory tooling assembly to bring the calibration feature within sensing range without need of manually jogging the sensory tooling assembly to a specific alignment position with respect to the calibration feature;
• e) recording robot configuration and new relative position and orientation (pose) of the calibration feature with respect to the sensory reference frame as an initial configuration data record;
• f) causing relative movement of the calibration feature and sensory tooling assembly along a known direction such that the calibration feature and sensory tooling assembly are still within sensing range;
• g) recording robot configuration and new relative location and orientation of the calibration feature with respect to the sensory reference frame as a secondary configuration data record;
• h) determining if the orientation of the secondary configuration is the same as the orientation of the initial configuration data record;
• i) if the orientation of the initial and secondary configurations are the same, an additional orientational change is required and is accomplished and recorded by causing relative movement of the calibration feature and the sensory tooling assembly such that the calibration feature has a different orientation from the orientation as determined in the initial and secondary data records, and recording robot configuration and new relative location and orientation of the calibration feature with respect to the sensory reference frame as a third configuration data record;
• j) applying coordinate transformations to the initial and secondary configuration data records, and to the third configuration data record if required, to generate a correct tool control frame (TCF) pose with respect to the CRF.