Energy-Efficient Trajectory Planning using Inequality State Constraint for Biped Walking Robot with Upper Body Mass

For the researches of biped walking robot, energy-efficiency is an important issue. We have proposed an optimal trajectory planning method based on a function approximation method, and applied it for 2D biped walking model. With the method, we obtained the solution of minimal square integration value of the input torque. Before that, this method only includes equality state constraint, but in this paper, also includes inequality state constraint to restrict the range of joint angle. In addition, we performed the walking experiment to verify the effectiveness of this method. We realized the stable walking of 0.6 s period and 0.3 m/s. Finally, we evaluated the energy-efficiency by specific cost