Final-state control of a two-link cat robot by feedforward torque inputs

This paper deals with twisting motion of a falling cat robot by two torque inputs around her waist. The cat robot consists of two rigid columns and has internally two actuators at the joint to generate torque inputs around the normal coordinates. This system is a nonholonomic system whose angular momentum is conserved. We obtain the Lagrange's equation of motion with nonholonomic constraint and formulate the linear parameter varying system. Then, in order to get the twisting motion we apply the error learning method of final-state control with amplitude constraint of inputs. In simulation we show that the two-link cat robot can pose so that she lands on her feet, by using of the obtained feedforward torque inputs by the final-state control.