Design And Gait Planning Of 3-5R Parallel Leg Mechanism For Quadruped Walking Robot

Compared with wheeled robots and crawler robots,walking robots have strong adaptability to various road conditions.The main point is that the walking points of the walking robot are discrete and the contact points are small.Moreover,the walking robot can adapt to road conditions such as potholes and gravel.In addition,the four-legged walking robot can achieve the stability performance requirements of the mounted platform through its own attitude adjustment.Compared with the series mechanism,the parallel mechanism is used as the walking robot leg mechanism,which can meet the requirements of smooth obstacle crossing and arbitrary angle switching when carrying the detecting device.It can increase the carrying capacity of the robot and cooperate with the control system to achieve higher precision control.In this thesis,a 3-5R parallel mechanism with three translational degrees of freedom is designed.The parallel mechanism is drnven centrally at the upper end of the leg.It is driven by a rotary motor and has high control reliability.A new type of the quadruped robot walking robot was designed with this parallel mechanism as the leg mechanism.The main research contents are as follows:The quadruped robot single-leg parallel leg mechanism is the research object.Start with the spiral relationship of constraints and degrees of freedom.The degree of freedom calculation is performed on the 3₅R parallel mechanism.Numerical calculations are performed on the forward and reverse solutions,end velocity and acceleration of a single foot.Verification mechanism corrects the correctness of theoretical values.Solve the Jacobian matrix.Analyze the influence of the input on the speed and acceleration of the moving platform of the mechanism and do the theoretical numerical calculation.The theoretical analysis results are verified by simulation of the three-dimensional model.The quadruped robot single-leg parallel leg mechanism is the research object.The kinematics analysis results were used to further analyze the dynamics of the mechanism.The Lagrange equation is used to derive the dynamics model of the mechanism.Combined with ADAMS software simulation,the curve of three driving torques when the stepping action is completed is obtained.Verify the correctness of the institutional dynamics analysis.The quadruped walking robot is the research object.Gait planning and stability analysis of walking and turning of a quadruped robot.The triangular gait of the quadruped walking robot is planned based on the principle of static stability.The stability of the quadruped walking robot under the gait is analyzed by the stability margin method.The diagonal gait of the quadruped walking robot is planned based on the principle of dynamic stability.The stability of the diagonal gait is analyzed using the Euler's formula.On this basis,the trajectory of the walking robot is obtained by simulating the gait of different initial poses.Determine the best initial pose.The turning gait of the walking robot is planned on the basis of the diagonal gait.The simulation verifies that the robot can reach the stability requirement under the turning gait.Co-simulation based on ADAMS and MATLAB/Simulink.The flip angle and pitch angle curves of the walking robot are obtained.The above conclusions verify the correctness and feasibility of the theory.The prototype of the quadruped walking robot is used as the experimental basis.Use the Arduino software platform programming software to write programs.The balance adjustment system and obstacle avoidance system of the quadruped walking robot are designed.The attitude sensor is used to test the stability of the parallel leg mechanism and the fuselage.A curve of pitch angle and flip angle is obtained.The feasibility of the parallel mechanism and the quadruped robot was verified.Straight motion test,turn motion test and obstacle avoidance test for the robot.