Design of bionic goat quadruped robot mechanism and walking gait planning

Abstract

In order to improve the walking stability and obstacle jumping ability of the robot on the slope, the goat was taken as the bionic prototype, a kind of bionic goat quadruped robot has been designed. By the bionic principle, the mechanical structure of the quadruped robot was designed, and the Denavit-Hartenberg (D-H) method was used to build the kinematic model, through which the forward and inverse kinematics of the robot was calculated, thus the equations of velocity and acceleration of the joint angle change were obtained during the quadruped robot motion, providing control theory foundation for robots. During walk gait planning, a low contact compact foot trajectory planning method using a high order polynomial curve was used to carry out the foot trajectory planning of the robot for the swing phase and stance phase. Through MATLAB software simulation, the simulation results of MATLAB software showed that the trajectory of the foot of the quadruped robot was semi-elliptic in a gait cycle, which were basically consistent with the foot trajectory obtained from the previous goat slope walking test. Therefore, the simulation results by MATLAB software showed that the foot trajectory was reasonable. Based on this, a gait plan was carried out, and the sequence of the lift leg steps of the robot was obtained. The test platform for the whole machine was built. The results showed that the height of the leg of the quadruped robot was 7.37 cm, and the length of the gait was 28.40 cm. Compared with the planned average gait length S=30 cm and average step height H=7 cm, the error of the leg height and the gait length was 5.28% and 5.33%, respectively. The designed gait planning achieved the expected results. The knee joint angle varied from 126.3° to 156.1°, and the hip joint angle varied from 103.9° to 138.4°. The changes in the joint angle of the quadruped robot could prove the correctness of the foot motion trajectory planning, which will provide a theoretical basis for the structural design and gait planning of the quadruped robot.

Design and analysis of an adjustable Stephenson-III closed-chain leg mechanism and its application in multi-legged robot

“…For example, the duty cycle of a bipedal robot must be greater than or equal to 0 . 5 during stable walking. A quadrupedal robot has a duty cycle of 0 . 75 in triangular gait 20 and 0 . 5 in diagonal gait. 21 For the support phase of the improved Stephenson-III leg mechanism, the crank angle is defined to be starting from 325° and terminating to 35°.…”

Parameter Calibration on Replacement Manipulator for UHV Valve-Side Bushing Based on Spinor Theory

“…At present, D-H parameter method is commonly used in manipulator calibration to establish kinematics model because its method is simple and easy to use. e D-H parameter method is used to establish the kinematic model in reference [27][28][29][30], but the D-H parameter method has a defect that cannot be ignored, that is, its motion can only revolve around the x-axis and z-axis, but cannot express the motion about the y-axis [26], which makes the singularity problem when the two continuous joints are parallel or nearly parallel, and the calculation process of the kinematic model of the manipulator with multidegree of freedom is complex and inefficient. In view of the shortcomings of the D-H parameter method, the MDH method has good kinematic characteristics and can find the forward and inverse solutions of the kinematic model [13,[31][32][33], but the singularity problem is still a great challenge.…”

Design and Test of Tread-Pattern Structure of Biomimetic Goat-Sole Tires

“…The team’s previous research found that the irregular shape of the goat’s foot surface could adapt to different ground and had a strong adhesion ability [ 25 , 26 , 27 , 28 , 29 ]. Therefore, in this study, the goat-sole were used as the bionic prototype, and the foot features were extracted, based on the bionic engineering principle, to carry out the study on the adhesion performance of tire tread-pattern structure of biomimetic goat-sole, which can effectively solve the problem of easy slippage during the walking process and provide an important reference for improving the passing performance of wheeled vehicles.…”