To provide zero moment point control using RHC(receding horizon control) capable of real-time optimizing calculation for a leg type robot, and control the robot through combined use of trajectory and non-linear controls using a zero moment point automatically generated in real time.

In the real-time optimal control method for the leg type robot, an optimal target ZMP(zero moment point) trajectory is obtained in real time when the zero moment point of the leg type robot satisfies an equality constraint of an expression: xzmp(uz-g)=x(uz-g)-zux, and when an optimal solution is obtained by use of an expression: uzmp(uz-g)=x(uz-g)-zux with xzmp used as new input uzmp.