Beschreibung
Ultrasonic piezomotors have been applied as a drive concept in miniaturized robot systems for many years. They have various beneficial characteristics, such as low costs, high accuracy and velocity. This has been demonstrated, with instance, with APIS, a miniaturized robot developed at the Technische Universität Braunschweig. With the example of APIS, this contribution discusses the challenge of signal processing techniques in order to combine different excitation methods for the piezomotors used in this robot. Since each excitation method influences the motor characteristic in a variety of ways, this research is motivated by desire for an optimal adaptation of certain features to a given trajectory, such as velocity, acceleration, moving direction or step resolution. Thus, our approach is to develop different ways to split a given trajectory into segments with regard to the requirements of the motor. So these segments can be linked to an excitation method which brings about the desired features. To this end, model trajectories are first generated and reasonable excitation methods for the piezomotor are identified and characterized. Key features are velocity, acceleration, moving direction and step resolution. Apart from defining key features, an assessment algorithm has been developed along with suitable weighting criteria. Finally the results, that is, each model signal together with the associated excitation method, are shown and validated. To achieve better results, possibilities for future developments are identified.
