An open control system architecture with an on-line velocity filter for industrial robots

As the industrial robot manipulators are widely used in various industrial fields, the limitation of traditional closed architectures for robot control systems becomes increasingly evident. It is almost impossible to modify the planning algorithms, the robot model, or the type of servo amplifier block. In this paper, an open architecture of robot control system is presented. It allows users to change the hardware architecture of the control system, e.g. change the geometric parameters of robots, the number/type of axes, and the servo amplifier block. It allows users to modify both the motion and interfacing software, e.g., modify/replace motion planning/control algorithms or change the human-machine interface to make it friendlier. In most traditional robot control systems, it is not provided to plan velocity profile on-line, which becomes essential in some applications. An on-line velocity filter with the function of look-ahead is thus proposed and implemented. It is integrated in the open-architecture robot control system, which provides users great flexibility to plan the motion on-line. Furthermore, the velocity look-ahead function guarantees the motion accuracy by imposing limits on velocity. Experiments validated the proposed velocity filter and the control system.