STRUCTURAL SYNTHESIS OF SERIAL SPHERICAL MANIPULATORS

Abstract

Serial manipulators are a serial of links connected by joints. The manipulator is called serial, because the drives of this manipulator are arranged in series, one after the other. Most often, the drives of the sequential manipulator are located on jointes or are coordinated with the joint. All links, the base, as well as the executive link, make up the kinematic chain of the manipulator. Serial manipulators have a large working area, it is much larger than the working area of parallel manipulators, which allows them to work with large parts, which undoubtedly increases the area in which the manipulator is capable of working. Mass-produced robots typically have six joints because at least six degrees of freedom are required to place a controlled object in an arbitrary position and orientation in the robot's workspace. The inverse kinematics of sequential manipulators with six rotary joints and with three consecutive intersecting joints can be solved in closed form, i.e. analytically This result had a huge impact on the design of industrial robots. This section provides a unified work for the calculation of the mobility and constraints in a general over constraint spherical manipulators based on spherical serial manipulator plus the different spherical structural groups with two, three and four classes. The results of the section can be considered by knowledges of structural groups with general constraint three constructed to the serial spherical manipulator with 3DoF. The 3DoF serial spherical manipulators represent as a series of 1DoF revolute joints with the axises intersecting in the center of sphere. Three illustrative examples showcasing the method are presented.