Nonlinear Adaptive Observer And Its Simulation In Vehicle State Estimation

Now more and more automobile vehicle active safety control system was installed on the center of mass of side-slip Angle is important in active safety control system control variable because of the high cost of directly measuring,the state observer is currently one of the main technologies of vehicle side-slip Angle estimation of the early research mainly using linear observer to estimate,such as Kalman filter and Luenberger observer in the linear region of the tire,the estimate result more accurate,but estimates in the area of the nonlinear error will be big,therefore,nonlinear observer to estimate method of side-slip Angle caused wide attention.However,due to the complexity of the road conditions of the vehicle,the parameters in the system need to be considered.Therefore,this paper designs an adaptive state observer for a class of nonlinear systems to study vehicle state estimation.In the process of the design of the observer to introduce a new nonlinear constraints: incremental quadratic constraints,and it contains a lot of common nonlinear conditions based on incremental quadratic nonlinear constraints,study of nonlinear system output nonlinear adaptive observer and adaptive observer design,for the vehicle state estimation observer is designed to provide premise conditions required for the main research contents and innovative points can be summarized as follows:1.Incremental quadratic constraint nonlinear system is studied in the adaptive observer design method,compared with common satisfy Lipschitz conditions of nonlinear system,this article introduced the increment quadratic constraints make the design of adaptive observer has generality for contains unknown parameters of the nonlinear system established adaptive full-order observer,and guarantee the status value of nonlinear system is given and the condition of the observer system estimates the error between the sufficient conditions for the asymptotically to zero.2.For adaptive full-order and reduced-order state observer design problem is proposed in this paper a kind of circle-criterion observer design method of nonlinear system: on the basis of the classical Luenberger observer design will be mapped to the output error in the system of nonlinear term,increase the observer design degrees of freedom,improve observer robustness in terms of application,using the classic Lorenz chaos system as well as the buick Rossler chaotic system model to demonstrate the effectiveness of the adaptive state observer design.3.Based on state space model of the vehicle,thinking of the nonlinear function to meet increasing output two constraints of the nonlinear system,nonlinear observer design for a class of output and on this basis,the output of nonlinear observer combined with adaptive observer,nonlinear adaptive observer design for a class of output in the end,the experimental data for the XC90 Volvo test car,front side-slip angle and the rear side-slip angle as the state variables,using MATLAB simulation software to verify the design output of the nonlinear observer effect in the vehicle state estimation.