Identification of the geometrical relationships of sensor, tool and actuator flange via defined machine movements for fully automated bracket installation

Sensor guided actuators have an increasing number of applications, largely due to the further development of automation systems with the aim to arrive at intelligent, adaptable, self-acting machines. This in turn brings new challenges. For instance, the pose of external positioning sensors mounted on the actuator's end effectors is generally not known with the required accuracy for most assembly operations. The procedures established in the industry for the identification of the sensor pose mostly do not consider all the degrees of freedom, and are, therefore, less precise. For this reason, costly constructions become a necessity if the low accuracies cannot be accepted. This paper proposes a modular approach that uses a numerical identification algorithm to determine the extrinsic transformation parameters of external positioning sensors and thereby define their geometrical relationship to the tool and actuator flange frame of the same end-effector. Furthermore, this article discusses the advantages of the calculation method used and gives an introduction into a future application in the aircraft manufacturing industry: fully automated bracket installation.