Multi-limbed robot in multi-point contact

This paper discusses the statics and kinematics of a multi-limbed robot in contact with the ground at multiple points. Contact at multiple points causes the indeterminacy of the contact force. The motion of the robot is constrained to maintain contact. We show that the robot has singular postures at which it has an additional degree of freedom and that the singularity also causes the indeterminacy of the contact force. The sliding motion of the robot is also constrained when the contact force is indeterminate. The relationship between the sliding constraint and the singularity is presented. We developed a quadruped robot which can take on various postures, e.g. lying on the ground and standing on the knees. The motion of the quadruped robot is analyzed as an example of a multi-limbed robot