Conception des robots rapides à consommation énergétique drastiquement réduite

摘要

It is well-known that one of the most representative future challenges in industrial robotics, is to increase the energy efficiency of robot manipulators. In industrial applications, such as high-speed pick-and-place operations, the accuracy is typically the most important criteria to measure the robot performance. Nevertheless, the design trends to operate at high speeds are shifting to the design of robots, which are not only accurate, but also they can perform in an energy-efficient way. This thesis proposes an actuation principle for reducing the energy consumption of high-speed robots by placing variable stiffness springs (VSS) in parallel to the motors that actuate the links of a high-speed robot. The main idea is to smartly tune online the force/displacement relation of the VSS, associated to the VSS stiffness, so that the robot is put in near a resonance mode, thus considerably decreasing the energy consumption during fast pseudoperiodic pick-and-place motions. By adding a spring with controllable stiffness in parallel to the robot actuated links, two performances are achieved: i) direct power connection between the motor and the robot links, thus ensuring accuracy at high-speeds; ii) control of the stored potential energy to be released per cycle of the pick-and-place motion, thus exploiting the robot natural dynamics at highspeeds, and therefore reducing the energy consumption. The experimental results of the suggested approach on an industrial-sized prototype show the drastic reduction of energy consumption for fast quasi-periodic pick-and-place-like motions.