Sensor-based design of a Delta parallel robot

This paper proposes a sensor-based design methodology in order to design a Delta robot with guaranteed accuracy performance for a dedicated sensor-based controller. This sensor-based design methodology takes into account the accuracy performance of the controller in the design process in order to find optimal geometric parameters of the robot. Three types of controllers are envisaged to be applied to the Delta robot, leading to three different optimal designs: leg-direction-based visual servoing, line-based visual servoing and image moment visual servoing. Based on these three controllers, positioning error models taking into account the error of observation coming from the camera are developed, and the controller singularities are analyzed. Then, design optimization problems are formulated in order to find the optimal geometric parameters and relevant parameters of the camera for the Delta robot for each type of controller. Prototypes of Delta robots have been manufactured based on the obtained optimum design parameters in order to test the performance of the pair {robot-controller}.