Trajectory Planning And Control Of Bionic Amphibious Robot

With the gradual acceleration of human exploration of the world,highly mobile exploration robots are increasingly needed from all walks of life.In the field of robot,amphibious robot plays a broad application prospect and important scientific research value in many fields,which makes many scholars study it,while the research and control algorithm design of mobile robot in the complex environment and underwater narrow space also bring great challenges to researchers.Combining amphibious movement with ground crawling,and exploring in narrow spaces,amphibious movement with limb structure is the greatest highlight of amphibians,beavers.At present,there are very few researches on the application of robots based on the motivation of beaver swimming,and based on the superiority of beaver motion mechanism,this paper focuses on the trajectory planning and control of beaver-like robots,and lays a foundation for the development of subsequent moth amphibious robots.In this paper,the physiological structure of biological beavers is analyzed,and a prototype of the hind limbs of the imitation beaver with open feet is developed.The wire rope driven by a single rudder achieves a foot-opening,which can be fully opened during the acceleration phase and fully contracted during the deceleration phase.And modeled on the overall size of the biological beaver set up a robot machine system,including the foot-opening module,the hind limb module,the forelimb module,flexible tail,control hardware module and so on.The kinematic parameters of the hind limbs of the imitation beaver robot are obtained,and the positive/reverse kinematic model of the hind limbs of the imitation beaver robot is established,which provides a theoretical basis for the subsequent ankle trajectory planning of the robot.The force of the feet is calculated by integral method,and the dynamic equation of the robot system is established by the Newton-Euler method,which provides the basis for the subsequent trajectory optimization.The leg trajectory of the underwater movement of the biological beaver and two typical swimming patterns are analyzed.In order to give full play to the characteristics of high efficiency and high speed of beaver swimming,a bio beaver swimming trajectory sampling platform was established,the movement trajectory of the biological beaver ankle and the angle of ankle rotation were analyzed by software,the sampling point of the ankle was interpolated by three B-splines,and a third-order Fourier control system was established,and the prototype of the imitation beaver's hind limbs was controlled by a parameter matrix of 4×5.According to the control of the robot machine,a multi-modal CPG network is built based on Hopp oscillator,and a variety of CPG sub-networks are realized by changing the activation state of the oscillator,thus generating a variety of gait,and reducing the control parameters and control complexity.Based on the mapping relationship between asymmetric sine function and virtual leg function and CPG parameters,the CPG parameters of the swimming gait and walking gait can be adjusted,the influence of CPG parameter changes on the robot can be seen intuitively,the parameters of different gaits are configured,and the problem of the current CPG control parameters is solved.A variety of gait of the robot is realized.Build a robotic underwater experiment platform to conduct a prototype test of a bionic beaver's hind limbs.Through the experiment in an asynchronous state,the efficiency of the bionic gait is verified.At the same time,the Froude efficiency is used to verify the efficiency of the bionic trajectory planning,and Through the multi-modal CPG control algorithm of the bionic beaver robot,a variety of gaits are generated.Through experimental observation and experimental measurement,the feasibility of the previous control algorithm and the correctness of related theories are verified.