| The omni-directional mobile robot having three degrees of freedom on the motion planehas got extensive focus and researches. It is able to run on the planar surface freely withoutchanging its posture, which is the advantages of omni-directional mobile robot toconventional robot. Therefore, the omni-directional robot can be widely used in anycongested environment and can move efficiently in all kinds of narrow and smallenvironments.In this paper, many related work about omni-directional mobile robots have beenextensively studied. In order to enhance the strength and stability of the wheels efficiently, themechanism is improved on the basis of the former research accomplishments about the wheelstructures and the first generation omni-directional wheel—MY(Mutual YoYo) by applyingdifferential principle on the design of the novel mechanism. According to the structure of thesecond generation of MY wheel, a robot kinematics model is built to analyze its performanceon vibration and control. By using Lagrange theorem, dynamic equation of theomni-directional mobile robot and kinematic characteristics of the robot are established,which provide theoretical basis of feasibility for the entire control system design and practicalapplication.According to requirements of the whole system stability and real-time response,double-layer structure control system is designed, which consists of a motherboard and acontrol–drive board. The motherboard mainly provides the system platform and thehuman-computer interface. And it also has to deal with the various kinds of user-tasks togenerate the motion instructions of robot and then transfer them to the control–drive board.When the control–drive board receives the movement instructions from the motherboard, itconverts the them into the target angle of each motor, and then control each motorsynchronously to finish the movement task of the whole body. In addition, some robotintelligent control algorithms, which do not need to interact with the users, are also installed on the control–drive board such as automatic obstacle-avoidance algorithm, indoor automaticpositioning algorithm and so on. On one hand, the intelligent control algorithms ensure thecontrol real-timely. on the other hand, they make the best of the processing ability of the chipson the control–drive board to reduce the burden of the motherboard. The control-drive boardis also responsible for the information acquisition of some sensors, and it will deliver theinformation to the motherboard whose IO exports are occupied through the serial bus. Finally,some tests are conducted to conform feasibility and validity of the whole control system. |
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