摘要 |
A method is provided capable of improving the accuracy of estimations of quantities that represent the state of a vehicle, such as vehicle speed, wheel slip ratio, wheel speed along the ground, longitudinal wheel force and the vehicle body sideslip angle, or values related to the quantities that represent the vehicle state, using a simple and inexpensive method. A tire longitudinal force computing unit <bold>81 </highlight>calculates longitudinal forces F<subscript>1 </highlight>to F<subscript>4 </highlight>of each of the wheels by substituting a coefficient of friction mu, which is adjusted such that a deviation between a detected value of a longitudinal acceleration G<subscript>x </highlight>and an estimated longitudinal acceleration G<subscript>xe </highlight>is zero, an estimated vehicle speed V<subscript>e</highlight>, slip ratios S<subscript>1 </highlight>to S<subscript>4 </highlight>of each of the wheels calculated based on detected values of sensors <bold>11 </highlight>and <bold>31</highlight>, loads W<subscript>1 </highlight>to W<subscript>4 </highlight>of each of the wheels, calculated based on detected values of sensors <bold>12 </highlight>and <bold>61</highlight>, and lateral forces Y<subscript>1 </highlight>to Y<subscript>4</highlight>, into an equation related to a predetermined tire dynamics model. A longitudinal acceleration estimating unit <bold>82 </highlight>calculates an estimated longitudinal acceleration G<subscript>xe </highlight>based on the longitudinal forces F<subscript>1 </highlight>to F<subscript>4 </highlight>and a predetermined movement equation. An integrator <bold>43 </highlight>integrates with respect to time the estimated longitudinal acceleration G<subscript>xe</highlight>, and calculates an estimated vehicle speed V<subscript>e</highlight>.
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