Position dependent linearized elastic models of parallel robot systems with embedded smart devices for vibration suppression control algorithms

The achievable accelerations of serial robot systems are limited by the weight of the axis drives, which are moved while traversing the given trajectory of the manipulator. By switching to parallel robot systems, it is possible to mount all drives on the rigid base platform. This reduction in weight of the movable linkage increases the possible accelerations, while retaining suitable position accuracy. Much weight can be reduced further on by using composite fibre materials for cranks and rods of each parallel linkage. Such systems are light and stiff and enable low cycle times, but unfortunately they are usually poorly damped as elastic structures and therefore tend to perform unwanted elastic vibrations during motion. In this paper, position dependent models are investigated, which are suitable to generate linearized elastic system models at arbitrary positions in the work space of the robot structure. These models are further modified to include active piezo electric patch devices as actuators and sensors, which can be used to control and observe the elastic structural deformations. The final electro-mechanical coupled system model can be used to develop and simulate state space vibration control algorithms.