Research On Landing Point And Foot Trajectory Planning Of Hexapod Robot In Complex Terrain

Under the coordination of all joints,the legged robot can change the motion mode of each leg according to the need,and adapt to different terrain with the help of feet in contact with the ground.This advantage makes legged robots more flexible than other types of robots to adapt to various terrain while maintaining their own stability.Among these,the hexapod robot can be more easily applied in the actual environment by virtue of its more stable structure and load capacity.At present,although hexapod robots have been able to achieve stable walking on flat ground,they are still unable to make good adaptability adjustment according to the environment when facing the complex terrain environment,which will become an important obstacle for the subsequent robot research.Therefore,this topic studies the landing point and foot trajectory planning method of hexapod robot in complex terrain,and expounds four parts: movement platform of bionic hexapod robot,terrain estimation and landing point planning method,foot trajectory planning,platform construction and experimental analysis.In the first part,the mathematical model of bionic hexapod robot is established by analyzing the structure characteristics of spider.Then,the D-H model of the robot is analyzed based on the relationship between leg joints and kinematics.Finally,on the basis of D-H model,the forward and inverse kinematics and foot motion space required by foot landing point selection and foot trajectory planning are derived.The second part combines environmental modeling to design the algorithm of terrain estimation and landing point planning.The terrain estimation of the bionic hexapod robot is realized based on the elevation map model updated with the robot movement.Topographic estimation takes into account the concavity,elevation difference,distance and other factors that affect the choice of landing point.The analysis results of these factors will also be an important consideration in the subsequent comprehensive evaluation.Finally,combined with the practical application requirements of bionic hexapod robot,the framework ideas used in the application process are summarized,and the key coordinate transformation content is elaborated.In the third part,the foot trajectory planning method of bionic hexapod robot is studied.Firstly,the robot control scheme combined with perception,mapping,landing point planning and related content of CPG rhythm signal are discussed.Then according to the robot needs to flexibly adjust the trajectory in complex terrain and the characteristics of the two trajectory planning methods,the neural Bessel curve is selected as the robot foot trajectory planning scheme.Finally,two kinds of raised and sunken ground were taken as examples to illustrate the foot trajectory adjustment strategy based on collision detection and CPG rhythm signal in complex terrain.The fourth part uses the bionic hexapod robot experiment platform to conduct map modeling experiment,raised ground trajectory adjustment experiment,depressed ground trajectory adjustment experiment and landing point planning experiment.It can be concluded from the experimental results that the map modeling accuracy and terrain evaluation results can provide an effective reference for the subsequent research content.The trajectory adjustment strategy in complex terrain can help the robot adapt to the environment.Combined with the map modeling,foot landing planning and foot trajectory adjustment strategies,the foot landing planning experiment was carried out,and the perceived terrain information was used to help the robot walk stably.