Tire grip level estimation apparatus and method, and running condition control method

摘要

A SAT estimator 16 estimates the SAT generated between the road surface and the tire. A lateral force detector 180 computes the lateral force generated in the wheels. A front-rear direction quantity-of-state arithmetic unit 240 computes the front-rear direction quantity of state generated in the wheels. A SAT model value arithmetic unit 22 computes the SAT model value from the lateral force value, the front-rear direction quantity of state, and tire parameter. Ratio computation means 28 computes a self-aligning ratio on the basis of the self-aligning torque estimated by the SAT estimator 16 and the SAT model value computed by said SAT model value arithmetic unit 22. A grip level estimator 26 estimates the grip level from the SAT model value computed by the SAT model value arithmetic unit 22.