| Three DOF omni-directional motion system in plane with four mecanum wheels was especially suitable for moving in a narrow space formed by lots of fixed and migratory obstacles. But it was only applied to soccer robot vehicle and forklift truck, and it adapted just for flat surface but not for the whole building environment so far. If it was extended to adapt to the whole building environment including narrow space, uneven ground and stair, it will be a flexible, stable and reliable moving system for service robot, which will promote application of service robot in building environment.A new omni-directional motion system completely adaptive for building environment was designed based on Mecanum-wheeled system, and the related technology problem was studied too.The main contents and conclusions of the dissertation include three following sections.1. Basic application technology sdudy. The structural features and motion characteristics of omni-directional system formed by Mecanum wheels were analyzed when it moved in flat ground, which aimed to solve three following technology problems of omni-directional Mecanum-wheeled system:(1) The"knock ground"problem was analyzed and solved. Based on the configuration features and the motion characteristics of Mecanum-wheeled system analyzed and summarized, the rule of"All roller surfaces must form a cylindrical surface"was a basic characteristic of Mecanum wheel, which was a basic condition to verify the design correctness of Mecanum wheel and a theoretical basis to solve the"knock ground"problem. Then a design example to solve the problem was given too.(2) The structural optimization problem of Mecanum-wheeled motion system was analyzed and solved. The rules and conditions how to construct the omni-directional motion system with Mecanum wheels were analyzed and summarized. The optimization framework of four Mecanum wheels motion system was presented based on analyzing the structural condition of system layout, the motion performance and the dynamic performance and system layout optimization problem was solved too.(3) The motion inefficiency problem of Mecanum-wheeled system was analyzed and solved. The motion characteristics of four Mecanum-wheeled systems were studied, and the kinematics model and dynamic model was obtained. Then the method and technical measure to improve the motion efficiency of the Mecanum motion system was propoed, which adopted the hybrid walking mode to improve the motion efficiency alternately using the omni-directional motion and the ordinary wheeled motion. Meanwhile a design example to implement the hybrid walking mode was given.2. Omni-directional Mecanum wheeled system was extended to adapt to the building environment and the main research contents were as follows.(1) A new motion system adaptive for plane ground and uneven ground with four Mecanum wheels was designed, whose kinematics model and dynamics model were presented. It was proved in theory that the above-mentioned models were the general models of omni-directional Mecanum wheeled system for plane ground and uneven ground.(2) A new Mecanum-elasticity wheel based on Mecanum wheel was designed. A new motion system formed by four above-mentioned new wheels was designed, which can not only omni-directionally move in plane but also climb stairs. Then the kinetic property and the dynamic characteristics were studied, and the stability conditions and the structure conditions of the system were given when climbing stairs.3. Application design and virtual prototype test. A new omni-directional moving platform was designed for serve robot to convey guests'baggages from first floor to intention floor in a hotel, which is a typical building environment. A virtual prototype was simulated to make sure the platform suitable for building environment.
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