Study On Control System Design And Stability Of Humanoid Robot

Humanoid robot, which contains mechanical technology, electronic technology, communications, computer technology and so on, is the most representative intelligent robot type, and the research in this field has become the hotspot of robotics technology. Stable and fast walk are the main signs different the humanoid robot from other robots, and it is also the basis for robots to realize its essential manipulation. This paper mainly focuses on the research on controlling of humanoid robot and the stability of walking.At first, the humanoid robot's body structure is introduced, and the distribution of freedom and the mechanical structure parameters are discussed; Then we analyze the demand of the control system with the consideration of the real-time, stability, expansibility and so on, and put forward the distributed control system architecture suitable for humanoid robot. The whole system is divided into three sections: main control layer, communication layer and execution layer. We chiefly analyze the requirements and the function of the underlying motion controller, and the design method based on DSP chip TMS320F2812 and the CPLD module is proposed, and the circuit design of the smallest system based on DSP is finished. These above provide the basis for increasing various functional modules.Secondly, we use the ZMP (zero-moment point) as a criterion about posture stability with the consideration of the factors on the stability of robot dynamic walking, and then we discuss the conditions of walking stability, and formularize the calculation expression of ZMP in space coordinates. Subsequent work is measuring force and torque information between the feet of humanoid robot and ground with the six-dimension force/torque sensors, and formularizing the calculation expression of real ZMP in space coordinates, which is used as criteria of stability through the actual motion of humanoid robot and provide a basis for gait adjustments online.Finally, according to the analysis on the robot walking stability we know that ZMP is closer to the center of support domain, the better performance of the robot's dynamic stability is, and while ZMP coincides with the center of support domain, the stability margin of robot's dynamic walking reaches the maximum. Therefore, as for the ankle, which is the greatest factor affecting on ZMP, two-dimensional fuzzy controller is put forward combining the theory of fuzzy control, and a simulation is made in MATLAB with fuzzy inference system, and the effectiveness of the fuzzy control system are verified by the simulation result.