Research On Gait Planning Of Humanoid Robot Based On Virtual Prototype

Robotics technology has become one of the frontier research field in moderntime, and humanoid robot is the most representative intelligent robot in all kinds ofrobot. Because humanoid robot has the similar appearance with the human beings,has the pattern of bipedal walking, and has more adaption to the environmentcomparing to the other forms of robot. Since humanoid robot can replace humanbeings to do the dangerous work, it will have significant prospect in the area ofaviation and military and so on. In humanoid robot research area, planning the gaitof the robot to achieve the stability of robot’s walking in the target circumstance isthe core problem. The paper mainly discuss the method of gait planning and balanceof the walking with the actual robot in our lab as the background and the virtualprototype of the humanoid robot as the research platform, the main work is asfollows:1.Using D-H rules established the robot’s model with the actual robot as thetype. Then the robot is simplified to the seven-connecting-rod model, and thegeneralized coordinate system is established for the whole robot, several localcoordinate systems are established for every connecting rod with their centroids asthe origin. Using D-H matrix rules established the forward and inverse kinematicsmodel. Then the relation between the posture of the robot and the main joint anglecan be obtained. According to the inverse calculation of the posture matrix, jointangle can be deduced, which is the basis of the gait planning. In the end, dynamicmodel are established by the dynamic equations for the one-foot and two-feet standstage.After analyzing the stability condition of the walking, the formula of thecenter of the gravity in slow speed and ZMP in the fast speed is deduced.2.With the ZMP as the standard, gait planning will be designed. Firstly motiontrajectory is calculated with the cubic spline interpolation method, according to therestrain condition. Secondly the actual ZMP trajectory is calculated according to theinverse kinematics equation. At last the goal of stable walking is achieved throughadjusting the parameter of the robot walking after comparing the ideal and actualZMP trajectory.3.Platform of the virtual prototype is established.3D robot model is established through the mechanics3D modeling software based on actual robot. Then the robotmodel is led to the ADAMS-dynamic analysis software, inputting the designed themotion trajectory and simulating the robot’s walking. After simulation, ADAMSwill output the video of the robot’s walking and the information such as jointmotion trajectory, angle, force, moment of force and so on to verify the feasibilityof gait planning.4.The planning joint information are input to the low computer program tofurther verify the feasibility of the gait planning. After verifying the simulation andthe actual robot’s walking experiment, the method of the gait planning is availableto make sure that robot can walk stably.