The Design And Obstacleavoidance Simulation Of Anovel7-Dofhybrid Homanoid Mechanicalarm

Humanoid arm is a hot spot of the robot research field. As a redundant robot, the7-DOF humanoid arm has many advantages like obstacle avoidance, singular pointavoidance and joint angle optimization. It’s very flexable and of high practical value.Almost all the humanoid arms are of serial structure till now, and a novel arm ofserial-parallel hybrid structure is promoted in this paper. The arm is made up by theshoulder, elbow and wrist joints, which have all used the parallel sphere5-R mechanism.So it’s a kind of hybrid mechanical arm that has the advantages of serial structure likelarge work space and the advantages of parallel structure like complex composition andlarge bearing capacity. It is flexible like a human arm, and the moving scopes are almostthe same as the human arm joints.The kinematic analysis of the joints and the hole arm was conducted, and theJacobian matrix was obtained. The obstacle avoidance algorithm by using gradientprojection method was given. A proper value of the factor k is needed during the obstacleavoidance algorithm, which can guarantee the obstacle avoidance performance withoutvibration. This paper gave a method of getting the proper value when the arm moved atthe constant speed, and the obstacle avoidance movement simulation was conducted. Wechose the type of the servo motors by load estimation, and checked their drive torques.Structural design of some parts was given, and the workspace of the joints were got.