Vertical Jumping of a Spherical Tensegrity Robot Using Reduced Active Tendons

Abstract

This letter presents the details of designing a spherical tensegrity robot with reduced active tendons to perform decoupled center of mass movement and vertical jumping. The constrained multibody dynamics of the robot interacting with environments is expressed as a set of differential-algebraic equations. Coordinate partitioning and coordinate mapping techniques are employed to express the dynamics of robot center of mass as a set of ordinary differential equations. The configuration of active and passive tendons is designed based on the tendon control effectiveness with respect to the dynamics of robot center of mass. An energy-based vertical jumping strategy is developed to store strain energy in passive tendons and to release the energy by actuating active tendons to accelerate the robot vertically. Experiments and numerical simulations are conducted to examine the feasibility of performing decoupled center of mass movement via robot morphing, robot vertical jumping, and robot vertical jumping with payloads.