Zero-moment point based balance control of leg-wheel hybrid structures with inequality constraints of kinodynamic behavior

Abstract

This paper discusses a balance control method with kinodynamic constraints for leg-wheel hybrid structures in an effort to improve the mobility of locomotion over hard, flat surfaces. Preliminarily, we defined a prioritized Jacobian and a prioritized inverse of Jacobian to formulate the dynamically decoupled model in the task space for the constrained multicontact multi-rigid-body system with a floating base. Our strategy has two tracks to accommodate the uncertainty and the complexity of the system dynamics. 1) The time-delay estimation and control are combined with the nonlinear programming. 2) Whole kinodynamic constraints are derived as functions of the control input. The proposed balance control algorithm allows the system to traverse desired trajectories satisfying the kinodynamic constraints and improves the mobility of locomotion. The effectiveness of the algorithm is tested with the dynamic simulations.

Rolling based locomotion on rough terrain for a wheeled quadruped using centroidal dynamics

“…However, in above works [7,8,9,10], the systems show only static maneuvers, and the simplified dynamics model or the kinematics-based controller limits the diversity of dynamic behaviors. Authors in [11] [12] used the ZMP index to generate the robot centroidal translational motion pattern to follow the ZMP reference in 2D and 3D space respectively. [13] extended the work in [12] and achieve the contact kinematics in the acceleration level.…”

Real-Time Motion Generation and Control Systems for High Wheel-Legged Robot Mobility

“…In particular, security, rescue, and life assist robots have attracted considerable attention. To meet those expectations, wheel-legged mobile robots (WLMRs) that have both leg and wheel structures have been developed [1]- [13]. There are many types of WLMR mechanisms, and almost all of them have the following favorable features: (a) stair locomotion and obstacle avoidance via a multi-degree-of-freedom leg mechanism and (b) a high energy efficiency wheel mechanism.…”

“…There have been several studies that focused on increasing the speed, stability of robots such as rovers [21] and mobile manipulators [22], [23]. In addition, An et al investigated ways of increasing the speed of WLMRs on the basis the ZMP [13]. They realized the ZMP control of a WLMR by feedforward and feedback compensation using a precise dynamical model.…”