A parameter setting method to find the required state estimation accuracy for a motion control method in merging scenario

Abstract

In this study, we propose a procedure for parameters setting of the motion control method to find the required state estimation accuracy. A lot of motion control methods have been proposed for automatic driving vehicles in recent years to reduce fuel consumption and drivers' mental load. Mode predictive control (MPC) method is one of the often‐used control methods in motion control of automobiles. The technique to find the required state estimation accuracy is necessary to implement a motion control method. However, to the best of the authors' knowledge, such a technique has not been presented in any literature before. Therefore, we proposed a parameter setting method to find the required state estimation accuracy, assuming a model‐predictive‐type motion control method designed based on an optimal control problem. The contributions of this work are as follows: (1) A specific procedure to set the control parameters is proposed. (2) To overcome the difficulty of the parameter setting problem, we divide the control parameters into two sets. The first set of parameters are unrelated to the robustness against state estimation errors, while the others are related. (3) The parameters in the first set are designed independently of the others, so that parameter setting can be easily accomplished. The parameters in the first set are designed to obtain desirable motion of the ego vehicles ignoring the errors. The other parameters are set to find the required state estimation accuracy. (4) The parameter tuning problem and the specification of the state estimation accuracy is considered together. As a result, once the control parameters are determined, the required state estimation accuracy is specified. As an example, a robust motion control method based on MPC for merging scenario was considered. Calculations for some cases were conducted to show the effectiveness of the proposed procedure. The results showed that, if the estimation errors in the displacements of the vehicles are bounded in [− 1, 1][m]and that in the velocities are bounded in [− 1/30, 1/30][m/s], desirable motion control is possible for all the tested initial conditions.