The Modeling And Research Of The Humanoid Waist Mechanism

Waist mechanism plays a very important part in the whole robot system, deciding the flexibility and stable of the robot motion. The research is based on the robot project coming from National "863" program. Through waist mechanism modeling and the motion control research, the paper has designed and manufactured a humanoid waist mechanism realizing three DOF motions, supporting the future research, like motion trajectory and balance control between the waist and robot arm.After analyzing and the motion of the human waist, the motion method of the human waist has been decided. Generally, human waist is able to revolve round the basic axis to realize three DOF motions, which are pitch motion, yaw motion and roll motion. By comparing the available designing thoughts, the "differential mechanism+single motion" has been adapted. The paper has built the model of the waist mechanism in CAD and simulated its motion. With the motion and mechanical analyze, more information can be required to improve the function of the waist mechanism.Waist’s control system has adapted an up-system and low-system structure. With PC’s powerful logical and calculation abilities, the HMI analyzes the instruction input by the user and transmit the essential parameters to low-system to control the motion of the waist mechanism. As the waist mechanism is a multi-DOF and multi-motor system, the low-system has applied CANopen protocol to control the motor. Meanwhile, with the servo PID algorithm, the accuracy of the waist motion has been improved.The paper has researched the robot Inverse kinematics based on the geometry method to acquire the basic theory for further research. Beginning with construction of the axis system, the paper has figured out the motion relation between the waist mechanism and the robot arm, while simulating the motion track of the waist mechanism and the robot arm in Matlab. The working space of the robot arm has been indicated by the geometrical figure, which is helpful to get the size of the enlarged part caused by the waist motion.The experiment system of the waist mechanism has been set up to realize the couple motion of the waist part and robot arm. The waist mechanism has been successful manufactured, which fully meet the design requirements of the mechanical system and control system. The experiments of the couple motion has been realized and he result has been collected to prove the efficiency of the waist mechanism...