Abstract:A new algorithm for vehicle longitudinal velocity using the nonlinear adaptive estimation method was proposed based on distributed drive electric vehicle. According to the information of longitudinal acceleration sensor and the feedback value of each wheel slip ratio, the vehicle longitudinal velocity was estimated and algorithm proved the longitudinal velocity estimation error convergence. Depending on each wheel slip ratio, the feedback correction proportion for estimation algorithm of each wheel speed estimation error was determined. The road slope was estimated online using recursive least square with forgetting factor in rampway. In addition, the longitudinal acceleration sensor information was calibrated by the slope estimation value for slope adaptive longitudinal velocity estimation. The amount of computations for this method was small but with high estimation precision. Furthermore, the effectiveness of the algorithm was validated through experiments under multiple working conditions.