MMS: A modular robotic system and model based control architecture

The Modular Manipulator System CMMS) is a general purpose user configurable modular robotic system that provides rapid and inexpensive implementation of standard or customized manipulator geometries of arbitrary complexity, tailored to the needs of individual. researchers or application engineers. Structures are configured from self contained 1-DOF rotary or linear JOINT modules, which include an on-board control processor, power amplifier, DC servomotor, high precision position sensor and a fast, rigid connect/disconnect latch. The joints are connected together by passive rigid LINK tubes (straight or 90 degree elbow), that define the manipulator geometry. These components are all offered in 5, 7, 10, 14 and 20 cm diameters, with power density and positional accuracy competitive with other commercial manipulators. A Fuzzy Associative Memory (FAM) system is used to capture the arm solution equations for the user defined arm geometry with minimal user input. Task motion commands define trajectories for the end effector in 6-D cartesian workspace coordinates, broadcast to all joints concurrently. The control processor in each joint solves for its component of the movement (a distributed real-time arm equation solution), which is input to a PID control loop that drives the joint servomotor. Central to the system is the Model Manager control program a model based data-now architecture, which integrates a dynamic workspace model off-line application program development real-time task execution or simulation. The program supports easy teaching of workspace locations, hierarchical programming of complex tasks, sophisticated tool trajectory control integrated workspace I/O, manual manipulator operation and an int(1)uitive user control interface. Additional components under development support automated planning for subtasks, line-model based vision capability to guide workspace interaction and cooperative operation of multiple arms. Various technical and economic advantages of the modular approach are presented and a video of module assembly and arm operation is to be shown.