Two-wheelers Of The Stability Analysis And Control Study

This dissertation mainly studies the stability, kinematics and its sliding mode control design for the robotic bike. Normal bicycle and high speed bicycle are modeled. The study initially resolves problems of controller design due to greatly varying parameters and disturbances for Two-wheel system. The design of the controller and study of control law that eliminating chattering and reaching phase of the variable structure sliding mode control is achieved and is applied to the design of the bicycle system successfully. The main contributions of this dissertation are summarized as follows:(1) Modeling the improving motion equations of nominal bicycle and high speed bicycle with special structure based on kinematics analysis of the bicycle' s motion. The solution for taking the tradeoff between the system simplification and realizable is discussed. This equations obtained is simple and clear in the physics concept. It is base for future study.(2) The results of stability analysis is proposed for a class of high speed, low height and aerodynamically faired single-track vehicles in crosswinds and disturbing. A solution of static problem and dynamics is presented. This research is an exploratory work.(3) A design method of variable structure controller with disturbance observer for class two-wheels with a special structure form is proposed. An alternative trade-off between the reduction of the disturbance and reduction of the influence of the sensor noise or the parameter fluctuation is discussed. The achievement, existence and stability condition of sliding mode control in robotic bicycle are investigated via Lyapunov stability theory. The resulting controller exhibits calculation and realization simply, and strong robustness properties.(4) Chattering free sliding modes in robotic bicycle control without decreasing the performance is presented. A main drawback of variable structure control is so-called chattering phenomenon. This research using function of inverse tangent shows that chattering effect can be smoothened and deleted by replacing the sign function by tangent inverse function . An algorithm which posses all good properties of sliding mode systems while avoiding unnecessarydiscontinuity of the control and the explicit calculation of the equivalent control. This control method is then applied to develop a control strategy for robotic bicycle. Good performances are obtained.(5) A method to eliminate the reaching phase from variable structure control for robotic bicycle is presented, and introduced an optimization procedure to insure optimal convergence parameters. The approach is based on modifying the sliding domain equations through the use of exponential functions. Such that the initial state of the system resided on a modified sliding surface. This modified surface exponentially converges to the original one. Once the system state reaches sliding surface it never leaves it. This feature may be used to accurately predict the system response without solving the differential equations, and to check whether the control remains within acceptable limits, in addition, the method insures optimal convergence parameters with respect to the tracking errors and control effort.Utilizing the theory studied above, the dissertation investigates the robotic bicycle design problem. Based on the analysis of bicycle dynamics, the eliminating reaching phase and reducing chatter siiding-mode control law with disturbance observer for robotic bicycle is determined. Digital simulation results shows that the suggested control scheme can overcome the influences on robotic bicycle in crosswinds and rough road effect and other no ideal factors, can obtains good transient performance and static tacking precision. The example also proves trueness and realizable of above theory research, and shows that robotic bicycle have good prospects on engineering applications.