Model Analysis And SMC Strategy Research Of Two-wheeled Mobile Car

Two-wheeled mobile car, viewed as a typical nonlinear system, is used in avariety of complex environment and could complete many tasks, such as its ownbalance, autonomous navigation, path planning and so on. As its instabilitydynamic characteristic and nonlinear characteristic, two-wheeled mobile car couldbe viewed as an ideal platform for the research of nonlinear theory and validationof complex control algorithms.The core movement balance control strategy of two-wheeled mobile car isinvestigated. In order to improve the system’s robustness, a sliding mode controlleris designed, with a view to reduce chattering, two solutions are designed based onthe boundary layer and higher-order sliding mode. To improve the efficiency ofbattery energy, energy optimization strategy based on PSO algorithm is proposed inthe process of path planning.The main research contents and contributions are listed as follows:(1) Although SMC method has a strong anti-jamming capability, the chatteringcould influence system’s performance. There are two essentially ways to counterthe chatter phenomenon, the most common way is the boundary layer and the otheris to use higher order sliding mode. Usually the boundary layer method will reducethe sliding mode control’s anti-jamming capability, therefore a global improveintegral Fuzzy-SMC method is designed by introducing an adjust factor whichtuned by real time fuzzy inference according to the system’s current states, whichleads the control input softened and reduce the chattering, at the same time, thisway could make the system’s robustness and good transient characteristics.(2) A second-order adaptive super-twisting SMC method is designed from theway of higher-order sliding mode. The design idea of second order mode is to makethe continuous action act on the second-order differential of sliding mode variables,which could effectively reduce the chattering phenomenon. Base on thesecond-order super-twisting algorithm control, an adaptive law is designed to adjustthe parameters, which not only reduces the complexity of parameters selected bytested, but eliminates the limitation of knowing the first derivative of interferenceboundary.(3) The energy consumption of battery is vital to the two-wheeled mobile car in the self-balance process. The square of the control inputs is used in the generalenergy control method as a consumption evaluation formula, in which the system’sstates are not considered. Based on the dynamics equations, the kinematic model oftwo-wheeled mobile car and motor model, the completely energy consumptionmodel is built. As the energy equations and constraints are complicated, it isdifficult to obtain the optimal solution. PSO algorithm is used to optimize theenergy function to get optimal speed interval range, which achieves system’senergy optimal control.