Abstract: SCARA robot is especially suitable for assembly work because of its high speed, high precision and mechanism characteristics, so it is widely used in 3C, food and drug, automobile industry and other production processes, such as assembling circuit boards and components. First, the trajectory planning, including basic trajectory planning, optimal trajectory planning and artificial intelligence trajectory planning was explained and classified , the advantages and disadvantages of various methods were summarized. The basic trajectory planning is polynomial and spline interpolation in joint space, velocity planning, linear and arc interpolation in Cartesian space; optimal planning includes time optimization, energy optimization and impact optimization; artificial intelligence is based on genetic algorithm and machine learning to plan trajectory. The realization of trajectory planning requires hardware foundation such as controller driver and control strategy guarantee. So the existing control system architecture and control methods were introduced. At present, the mainstream control systems include motion control card and industrial bus, and the use of industrial Ethernet can realize the networking of automation systems. At the same time, in order to facilitate readers to choose the appropriate SCARA robot, the domestic market situation was introduced, and the performance,advantages and disadvantages of some products were compared. At last, the future development was prospected,including drive-control integrated control system, modularization of robots ,and human-machine cooperation.

       Key words: selective compliance assembly robot arm(SCARA) robot; trajectory planning; structure of the control

system; product's comparison; integration of drive and control