Use of the cog representation to control a robot with acceleration feedback

A controller using acceleration feedback has been applied to a flexible robot for which the position and velocity of the load are not measured. It is shown by using the Causal Ordering Graph (COG), that the motor can be controlled by using acceleration feedback and that it allows an exact tracking of the motor position, irrespective of the non-linear flexibilities of the axis and of the measurement disturbances. This easy-to-tune algorithm, in which main control parameters are the modal masses of the motor and load part and only consists of a positive acceleration feedback plus a PD controller, has been validated on an industrial 3-axis robot.