.3 Degrees Of Freedom Flexible Arm Experimental Platform

Robot technique has been widely used in many fields, and has become an important part of automatic production. Controller design and dynamic modeling of flexible manipulator are advanced topics in robot technique research area. In this paper, we design and construct one three-degree-of-freedom flexible arm experiment platform. On this experiment platform, we also do some research on dynamic modeling of flexible manipulator, and robot control system.In this paper, we first analyze the implementation scheme of this flexible arm experiment platform. We propose and design a four-bar mechanism as its mechanical structure, use fully digitalized AC servo system by harmonic retarder as its driver scheme, propose an open architecture which suits robot control, and choose "PC + DSP-based motion controller" as its control scheme. Based on these implementation schemes, we use industrial computer and PMAC (Programmable Multi-Axis Controller) to constitute the control system of the flexible arm, and implement a three-level half-closed-loop control, which uses electric current, speed as inner-loop ari location as outer-loop.Based on this experiment platform, we give flexible arm's kinematics equation under both spherical coordinate and Cartesian coordinate. We also implement two trajectory control algorithms of PTP (point to point) and CP (Continuous Path Control).Using lumped mass model, we construct dynamic equation of the flexible arm as well as its Simulink model. Using Simulink model, we analyze how Coulomb friction, motor inertia and reduction ratio of gear affect system performance.We do some research on infection of tuning PID parameter of PMAC and parameter of Notch Filter to dynamic performance of the flexible arm. Communication between computer and PMAC was done by Pcomm32 function. We use objected-oriented technology and module method to design friendly control system software.The four-bar mechanism we propose to transfer the movement from motor to end of the arm can effectively simplify dynamic model of the arm. The control system hasopen architecture, so it's easy to integrate other peripheral equipments, and can be a good experiment platform for robot control algorithms. The mechanism by which we construct dynamic equation for the flexible arm can be used to model any kind of concentrated mass flexible arms.This system presents very well the structure, working principle, and working process of robots. It can also be used for research on dynamic modeling for flexible arms as well as new control policy.