A quadruped robot which can take various postures

We developed a quadruped robot which can take various postures, e.g. lying on the floor and kneeling. When the limbs are free from supporting the body of the robot, they can serve as arms. Up to two limbs can be freed from supporting the body when the robot kneels. The motion of the robot is constrained if it maintains current contact with the floor. The paper analyzes possible motions of the robot to maintain current contact. We show that even if the same parts of the robot are in contact with the floor, there exist singular postures at which the body of the robot has an additional degree of freedom