Analysis And Design Of Three Motors Drive4-Dofhybrid Mechanicalarm

A new hybrid mechanical4-DOF arm diven by3motors is promoted. The forwardand inverse position solution, kinematics and workspace are analysed, and prototype isdeveloped.The shoulder joint consists of a spherical2-DOF orthogonal parallel mechanism,and it’s driven by a motor through the clutch brake. The shoulder joint can realize2-DOFrotational movement. Waist joint and elbow joint each has a rotational movement.thethree joints are put together in serial structure, and in this way the4-DOF movement isrealized by the three motors.The forward and inverse position solution of the orthogonal spherical2-DOFparallel mechanism is deduced, and we got the forward position equation and Jacobinmatrix of the mechanical arm. The work space contour map is drawn on the basis of themechanical arm structure constraint condition.We got the trajectory planning of robot grabbing, simulated the grabbing by usingthe simulation software, then got the mechanical arm speed and stress changes situationin the process of movement, and it can provide data for the mechanical arm structure.According to the proportion of the human body, we designed the mechanical armparameters while taking its manufacture and assembly technology into consideration.then developed the mechanical arm prototype.The mechanical arm has a lot of advantages like compact structure, light weight,smaller transmission error and larger work space. In addition its control system is simple,and it has good fabrication procedure. The arm can be widely used in modern industry,aerospace and other fields.