Research On Gait Planningand Control Strategy For Biomimetic Hexapod Robot

With the rapid development of science and technology, there is an urgentdemand for a kind of robot that can work in special environment. Compared to thewheeled and tracked robots, multi-legged robot especially hexapod robot shows astronger ability to adapt to the environment, which at the same time is lessdamageable to the environment and more flexible, the redundant structure alsoguarantee a stable walk with leg amputations. However its unique structure makesthe motion planning and control more complex, which become the key to thedevelopment of hexapod robot.The purpose of this topic is design gait planning methods for the hexapod robotHITCR-II, on that basis propose a control strategy to achieve stable walking incomplex and unknown environment.First of all, the kinematic is analysed on the basis of the hexapod robotHITCR-II’s mechanical structure utilizing the D-H method, its forward and inversekinematics eaustions are derived on the basis of the series-parallel structure, theworkspace of the hexapod robot’s foot is analysed, the kinematic equations areverified by simulation.Secondly, gait of the hexapod robot is planned, strategies of tripod gait’sstart-stop and cycle and quadripod also five-feet gait’s start-stop in stance phase areproposed, which guarantee a stable and continuous walking, combine with methodof planning foot trajectory and kinematic equations, several typical gaits aresimulated in Adams and the gait planning method is verified. A strategy of walkingon complex terrains is proposed utilizing several gaits’ combination, which is alsoverified in Adams.A kind of control strategy is presented for the robot HITCR-II, the controlsystem is divided into several submodules according to different functions. Free gaiton plane is achieved based on local principles and foot trajectory method plannedfor it. A control method of stance legs’ joints is proposed based on feedback of thebody position, a planning method of swing legs’ feet trajectory is designed utilizingthe BP network, combine with the switch submodule that embed local principles thehexapod robot can walk in complex and unknown terrains. The two kinds ofdistributed network control methods are verified in Matlab.Finally, the experiments of typical gaits and free gait on plant are done on thebuilt experimental platform to verify the gait planning and control strategy futher.