Design Of Control System For Microassembly Robot

Microassembly robot is the product of the robotic assembly processes and micromanipulation technologies. Despite its size is not necessarily tiny, it is able to achieve micron-level, even nanometer-level operations in a small workspace (cm-scale). Supported by National Science Foundation and China 863 Program, the dissertation builds a microassembly robot with 21 degrees of freedom and mainly discusses the design scheme of its control system to solve the problem that the traditional manual assembly of certain micro-parts sub-millimeter sizes has some disadvantages, such as low assembling accuracy, a low success rate and great worker's labor intensity.Control system is crucial to a microassembly robot in completing complicated assembling processes. The dissertation first introduces the overall design scheme of the control system and its hardware structure. Two kinds of micro-grippers and corresponding control systems, of which hardware structure and critical circuits are emphatically discussed, are developed.Control scheme of the microassembly robot is discussed. Several topics have been discussed about the positioning control scheme of micromanipulators and the operation control scheme of micro-grippers respectively, such as functionality in microassembly, control structure and physical control signals. Coordinates of the system workspace are defined.The control software is then decomposed into relevant functional modules which are grouped into two stages in controlling the whole microassembly process. Four-layer architecture design pattern, which is based on the .NET Framework, is proposed as a general solution for simplifying the writing of software modules. The characteristics of the pattern and relationship between software modules are briefly introduced. Functionalities of each layer and its implementation details are then emphatically discussed.The proposed design scheme is applied to construct an actual microassembly system with visual feedback. Communication protocol between micro-vision system and control system is presented. Debugging steps of the system and human machine interface of the software are given.