Symmetric kinematic formulation and non-master/slave coordinated control of two-arm robots

This paper deals with the design of the foot trajectory for a quadruped walking machine. Such walking machines should be capable of both uneven terrain walking and high-speed flat surface walking. The static walking method was used for uneven terrain walking and the dynamic walking method was used for plane walking. In the case of dynamic walking, the relative speed between the foot and the ground causes instability in the balance of the body. A foot trajectory is designed based on two points: the kinematics of foot motion and the relationship between joint motion and joint driving torque. A method for reducing the impact force upon initial contact with a floor by designing a periodic foot trajectory based on the wave motion of a cam is discussed. In this method, vertical and horizontal motions of the foot trajectory were generated independently using cycloidic motion. We named this trajectory the composite cycloid foot trajectory. We further developed a modified cycloidic foot trajectory by smoothing the joint angular acceleration. robots are studied from the standpoints of statics and kinematics; coordinates to describe these tasks are derived theoretically, on which forces, velocities, and positions are defined consistently. Based on those results, a hybrid position/force control scheme which distinguishes neither a master robot nor a slave robot is presented for the coordination of the two robots. In the static and kinematic analyses, the concept of a 'virtual stick' is introduced, which is used to make the motions of the two robots be considered at the centre of the object. Thus, use of the matrix pseudo-inverse technique decouples the motions into absolute and relative motions. Generalized forces, velocities, and positions are derived theoretically in those decoupled subspaces. These forces, velocities, and positions are symmetric functions of the jointspace forces, velocities, and positions.