An over-constrained few-joint five-freedom-degree parallel serial
robot mainly comprises a fixed platform, erect type vertical frames, a single-rotation-pair rotation frame, a double-rotation-pair rotation frame, a movable platform, a work platform, three
branch chains the same in structure and a two-freedom-degree posture adjusting head. The work platform is arranged in front of the fixed platform, and the erect type vertical frames which are symmetrically arranged are arranged on the two sides of the fixed platform correspondingly. The three
branch chains are arranged between the two erect type vertical frames and the movable platform, and the two-freedom-degree posture adjusting head is arranged at the lower end of the movable platform. A two-rotation and one-motion three-freedom-degreeparallel mechanism is formed by the erect type vertical frames, the movable platform and the three
branch chains. The over-constrained few-joint five-freedom-degree parallel serial
robot is simple instructure, the integral rigidity of the structure is improved, the control difficulty is lowered, the
kinematics analysis is simple, and the dynamic response is good. Through combination of a two-freedom-degree swinging head and the movable platform, the
work space of a
machine tool is enlarged, the sensitivity of the
machine tool is improved, and error accumulation caused by the component
machining error and the assembling error is effectively avoided.