Patent ID: 8744686

Claim:
A turning characteristic estimation method for a vehicle, comprising: obtaining an actual yaw rate of the vehicle; obtaining a vehicle speed of the vehicle; obtaining a steered angle of front wheels of the vehicle; obtaining a lateral acceleration of the vehicle; calculating a steady-state basic yaw rate based on the obtained vehicle speed, the obtained steered angle and the obtained lateral acceleration; calculating a plurality of transient yaw rates based on the calculated basic yaw rate using a steering response equation in which the transient yaw rate is expressed as having a first order delay relative to the basic yaw rate, wherein the steering response equation comprises a time constant of the first order delay, and wherein each of the plurality of transient yaw rates is calculated based on a corresponding different reference value of a time constant coefficient which is a coefficient multiplied to the vehicle speed in the time constant of the first order delay; calculating respective differences between each of the plurality of transient yaw rates and the obtained actual yaw rate; selecting a reference value among the plurality of reference values corresponding to the transient yaw rate having a minimum difference to the actual yaw rate as an estimated time constant coefficient of the steering response, which represents the turning characteristic of the vehicle; and updating each reference value based on the estimated time constant coefficient; wherein the turning characteristic estimation of the vehicle is performed by an electronic control unit.