Marsbot: A monopod robot capable of achieving three-dimensional dynamic and stable jumping

Abstract

Continuous, stable and accurate jumping in three-dimensional (3D) environment is one of difficulties of jumping robot research. In this paper, a monopod jumping robot Marsbot whose center of mass (CoM) can accurately reach desired positions in 3D space is designed. Based on the spring loaded inverted pendulum (SLIP) dynamics model, the take-off velocity control of Marsbot was realized, which made controllable continuous jump possible. Based on the reaction wheel pendulum (RWP) dynamics model and the law of conservation of angular momentum, the real-time 3D attitude control of Marsbot with three inertial tails was realized. By integrating SLIP model, RWP model and the post-landing steering strategy proposed in this paper, a continuous jump algorithm for CoM of Marsbot to accurately reach desired 3D positions is proposed. This paper proposes the air target grasping strategy of Marsbot (the author will elaborate on this issue in another article): When the robot jumps to the desired grasping position in the air, the robotic arm can quickly and stably grasp the target object such as tree branches, so that the robot can perch or hang on the target object, and get a good view from high place. The simulation results show that Marsbot can achieve continuous, stable, accurate jumping and realize air perching/observation operations through the above schemes. The simulation results also verify feasibility of the 3D jump dynamics model and its control algorithm proposed in this paper.