2019/09/27 by Eric Ambrose, Aaron D. Ames, Ambrose, Eric +1
Engineering · Physics and Astronomy · #Robotic Locomotion and Control #Micro and Nano Robotics #Control and Dynamics of Mobile Robots
paper · pdf · doi:10.48550/arxiv.1909.12930
Robotic Hopping is challenging from the perspective of both modeling the\ndynamics as well as the mechanical design due to the short period of ground\ncontact in which to actuate on the world. Previous work has demonstrated stable\nhopping on a moving-mass robot, wherein a single spring was utilized below the\nbody of the robot. This paper finds that the addition of a spring in parallel\nto the actuator greatly improves the performance of moving mass hopping robots.\nThis is demonstrated through the design of a novel one-dimensional hopping\nrobot. For this robot, a rigorous trajectory optimization method is developed\nusing hybrid systems models with experimentally tuned parameters. Simulation\nresults are used to study the effects of a parallel spring on energetic\nefficiency, stability and hopping effort. We find that the double-spring model\nhad 2.5x better energy efficiency than the single-spring model, and was able to\nhop using 40% less peak force from the actuator. Furthermore, the double-spring\nmodel produces stable hopping without the need for stabilizing controllers.\nThese concepts are demonstrated experimentally on a novel hopping robot,\nwherein hop heights up to 40cm were achieved.\n