On the synchronization of a pair of independent windshield wipers

This brief deals with the synchronization of a pair of windshield wipers in opposition, each one driven by its own independent motor. Here, the traditional rigid mechanical coupling driven by a single almost constant speed motor has been removed for the sake of weight and space. Therefore, collision avoidance and reference trajectory tracking must be guaranteed by feedback and synchronization. Collision free reference trajectories and a PID output feedback are designed using flatness and pole placement. Synchronization is obtained by clock control, i.e., delaying the reference trajectory of the following wiper when the leader is behind its reference trajectory.