加速度センサを用いたタイヤと路面間の最大すべり摩擦係数のリアルタイム推定

抄録

Antilock braking system (ABS) is used to control the damping force of a brake to prevent from locking. ABS based on a digital PID control law is most popular. However, the effectiveness of ABS is strongly dependent on the friction characteristic between a tire and a road surface. This characteristic changes every moment, while a vehicle moves. Therefore, the practical applicability of the conventional ABS is low. In this paper, a new ABS based on an accelerometer is proposed. First, both vehicle and wheel velocity are acquired in real time and a slip ratio is continuously calculated from these data. Second, the maximum value of accelerometer within a definite period of time is calculated, this slip ratio obtained at this moment is defined as a reference value of a slip ratio. Finally, a vehicle is controlled by the conventional PID control so that this reference value of a slip ratio is kept. The reference value changes with time. Simulation results show that the effectiveness of the proposed ABS with PID control is verified; since the stopping distance becomes shorter than the case of a conventional ABS. Therefore, the proposed method is easily implemented due to simple architecture and low cost.