Design And Performance Analysis Of Hexapod Mobile Robot Based On Trunk Mechanism

Compared with the wheeled or tracked robot,hexapod mobile robot is able to adjust its leg mechanism,and change the landing points into discrete points,which is more suitable for unstructured environments.Hence,hexapod mobile robot has been widely concerned and researched.However,at the moment,most of them are merely equipped with basic,low-dexterity motion capabilities but lacking of structure innovations of redundancy to coordinate with leg mechanisms thus to meet multi-mode,high-dexterity motion capabilities.In view of this problem,a hexapod mobile robot based on the trunk mechanism is designed in this paper,and related motion performance research is carried out.With the working performance requirement of robot in complex environments,firstly,a hexapod mobile robot structure based on the trunk mechanism is designed in this paper.Secondly,the inverse position and posture equation is derived through constructing vector closure method,and a mathematical model of mechanism speed and acceleration is constructed by using the time derivative method of the inverse solution equation.Thirdly,the virtual work principle and Jacobian matrix are adopted to derive the kinematic performance equation of the constraint static,stiffness,dexterity and workspace between each stage of the moving platform and the active lever.In addition,the D-H representation is used to establish its mathematical model between length of driving branch chains,corners of leg joints and spatial position of feet.And then,the tripod gait is adopted in the hexapod mobile robot's gait planning as well as step size calculation of straight walking,turning corner,obstacle avoidance movements and rolling.The combination of the results and its simulated analysis on virtual prototype verifies the correctness of theoretical model of gait planning.What's more,the static stability criterion based on the minimum distance between the projection point of CG and that of each supporting foot derives the stability margin equation,which further guarantees the stability of the robotFinally,the STM32 chips are chosen as the control mainboard of the hexapod mobile robot in the paper and further to establish the hardware and the software control systems in each functional module.The communication between the upper computer and the lower computer,and research on model machine's trunk mechanism,leg space,corner turning,obstacle avoidance and climbing are achieved by the robot motion control program written by Keil Uvision 5.It turns out that hexapod mobile robot based on the trunk mechanism owns feasibility and sound motion capabilities.