1. A motion-control system for moving a mass according to different tasks, comprising: at least one controllable actuator for performing the different tasks; an input module for receiving a specific task to perform; a controller for controlling a performance of the specific task by the controllable actuator according to a specific control law; a tunable actuator having a tunable parameter of mechanical response, wherein the tunable actuator is mechanically arranged in the system, such that different values of the tunable parameter change dynamics of the system; and an optimization module for jointly selecting a value of the tunable parameter and the specific control law based on the specific task.