Research Of Hexapod Bionic Robot On Vision And Gait Stability

Multi-legged walking robots mainly imitate multi-legged creatures such as spiders and ants,and have been widely used in many fields due to their strong terrain adaptability,good mobility,large carrying capacity and strong flexibility.Aiming at the current research of the hexapod bionic robots such as slow motion,difficulty in maintaining the balance of the fuselage,low work efficiency,and poor flexibility.In order to improve the adaptability of the hexapod bionic robot to rugged terrain,a hexapod bionic robot based on Raspberry Pi visual navigation is developed in this thesis.The specific research contents and results are as follows:(1)Based on the analysis of the ant's body structure,a hexapod bionic robot frame model including mechanical legs,mechanical arms,and vision system is designed.Based on actual demand analysis,robot camera,photoelectric sensor,motor and other hardware are equipped.The programming and transplantation of the robot control program is realized,and the overall construction of the hexapod bionic robot is completed.(2)Construct a target video capture and collection mechanism based on Linux system,and achieve target video image acquisition through Video4Linux2 technology.The three-dimensional block matching denoising algorithm is improved,which reduces the amount of calculation by about one-fifth compared with the original denoising algorithm.Perform morphological preprocessing such as grayscale,histogram equalization,improve three-dimensional block matching denoising,binarization,edge detection,and corrosion expansion on the collected images to achieve the separation of the target foreground and background,and obtain obvious edge information.The recognition and positioning image of the hexapod effectively improves the real-time and accuracy of target recognition and positioning of the hexapod bionic robot.(3)The forward-inverse kinematics equations of the robot are derived,and the kinematics model of the hexapod bionic robot is constructed by establishing the Denavit-Hartenberg coordinate system and gait model.The method of polynomial difference fitting is used to plan the gait of the robot's swing phase and support phase.The gait methods of different number of swings and supports are studied to researchtheir effects on the walking speed and gait stability of the robot.Simultaneously,the foot-end trajectory and gait pose of robots with different structure sizes are simulated and analyzed.It is found that the smaller the calf length,the smaller the turning radius,the more stable the robot,but the lower the turning efficiency.(4)Based on the stability analysis of hexapod bionic robots,it is found that linear gait leg length and step length have an opposite relationship to stability.Apply the trajectory function of the support phase and the swing phase to analyze the angle changes between the three joints of the support phase and the swing phase.The reliability of the balance control of the hexapod bionic robot is verified by simulation and physical objects.The results show that the walking gait design method based on the Denavit-Hartenberg coordinate system,the coordinated control strategy of mechanical leg support and swing,and optimized target recognition denoising algorithm can enable the hexapod bionic robot to walk stably and effectively while accurately identifying,positioning and approaching aims.