Design And Analysis Of A Quadruped Walking Robot With Parallel Leg Mechanisms For The Elderly And The Disabled

Using the parallel mechanism as leg mechanism, combined the advantage of the modular robot and reconfigurable robot, a novel reconfigurable quadruped /bipedal walking robot with parallel mechanism for the elderly and the disabled is proposed in this paper. It is intended to provide a more convenient walking robot for the elderly and the disabled. The research results not only have high academic value that will develop a new application field of parallel mechanism, but also have important social significance that will improve the quality of life of the elderly and the disabled.Firstly, the concrete application condition of manned robot is analyzed. The mechanical design of quadruped /bipedal reconfigurable walking robot, parallel leg mechanisms, and reconfigurable device is accomplished.Secondly, taking the quadruped parallel walking robot as the object of study, the movement characters of robot are analyzed. The kinematics problem of the robot can be transformed into the kinematics problem of one parallel leg mechanism. The position analysis of the quadruped parallel walking robot is accomplished. From the mechanisms point of view, the robot is equivalent to the parallel mechanism with different branch number. Using the parallel mechanism theory and influence coefficients theory, the velocity and acceleration of robot is analyzed. Using MATLAB program, kinematics numerical example is analyzed.Thirdly, the dynamics modeling of the single swing leg is analyzed. Using MATLAB program, numerical examples of the kinematics and dynamics are analyzed. The compatibility equation of the quadruped parallel walking robot is established under the actuation redundancy. Using the weighted least square method, the optimal coordination distribution of the dynamic loading is achieved. Fourthly, an effective foot trajectory of the single leg mechanism is planned by the method of composite cycloid trajectory planning. Under different motion mode (such as: dynamic walking, static walking, four feet standing), multiple combinations of the redundant inputs and their superiority-inferiority are analyzed.Lastly, both the single swinging leg and the quadruped walking robot with parallel mechanism were simulated by ADAMS. On the one hand, the simulation results proved the accuracy and validity of the kinematics and dynamics model. On the other hand, according to planned foot trajectory, we can gain the curves of the actuator displacement, velocity, acceleration and driving force. It lays a foundation for the drive motor selection and robot control.