Research On Controlsystem Of Frog-inspired Hoppinglegpowered Bypneumatic Muscle

The research on bionic hopping robots is becoming a popular subject recentlydue to its characters of strong obstacle-overleaping ability and great field andenvironment adaptability. Analyzing the previous frog-inspired hopping robot, theoptimization and improvement programs are proposed and verification for the newrobot is made in ADAMS. The mathematical models of the pneumatic muscles werebuilt by experimental method and the position control method for pose alignment ofthe robot was designed. Besides, a control system is proposed in this dissertationand to realize different jumping modes.The ideal mathematical model of the pneumatic artificial muscle was derived.Based on the ideal model and considering the factors which affect the musclecharacteristics, a new improved mathematical model was deduced. Then theimproved model was compared with the experimental curves and idealmathematical model. Considering the demands of designing controller forpneumatic muscle, in this dissertation, a modeling method which builds simplemathematical model of pneumatic muscle was proposed, and the mathematicalmodels for the pneumatic muscles used in the robot were built with the proposedmodeling method. Furthermore the correctness of this model was verified by theexperiment.Considering the influence of the take-off angle on the jumping performanceand based on the mathematical model of the pneumatic muscle, a control strategyfor pneumatic muscle by the fuzzy control and double-layer PID control wasproposed in this dissertation to adjust the take-off angle of the robot. The systemsimulation was made in the MATLAB Simulink and the accuracy of the controlstrategy was tested in the experiment.With improving and optimizing the mechanism design deficiencies, a newrobot is designed. The force sensors and angle sensors is equipped on the new robot,thus the robot has the ability of force/angle closed-loop control and angleacquisition of joints. Besides, ADAMS simulation was performed to test thejumping ability of the new robot.Experimental platform of the bionic hopping robot control system is bulit, andthe robot pose alignment and jumping experiments are conducted based on theexperimental platform to validate the proposed muscle position control strategy andthe effectiveness of control system. In jumping experiments, the robot’s abilities tobroad-jump, high jump and climbing over obstacle were tested repeatedly to findout the factors which affect the jumping performance. This experiment laid a foundation for further optimization and improvement.