| 摘要 |
A road surface friction coefficient estimating device includes a means which finds a first estimated value Mnsp_estm of an external force to be compared (S102 to S116, S118-2), a means which finds a second estimated value Mnsp_sens (S118-1), and a plurality of increasing/decreasing manipulated variable determining means 34_k, each of which determines the increasing/decreasing manipulated variable Δμ_k of the friction coefficient estimated value on the basis of the first estimated value Mnsp_estm and the second estimated value Mnsp_sens, and updates the friction coefficient estimated value according to Δμ_k. The increasing/decreasing manipulated variable determining means 34—1 and 34—2 determine Δμ—1 and Δμ—2 according to a deviation in filtering value between the first estimated value and the second estimated value, and the increasing/decreasing manipulated variable determining means 34—3 determines Δμ—1 according to the deviation between the first estimated value and the second estimated value. |
| 主权项 |
1. A road surface friction coefficient estimating device which estimates a friction coefficient of a road surface, on which a vehicle is traveling, while updating the friction coefficient, the device comprising:
a first estimating element of a to-be-compared external force which
defines, as the to-be-compared external force, a predetermined type of an external force component acting on the vehicle due to a resultant force of road surface reaction forces acting on each wheel of the vehicle from the road surface, andfinds a first estimated value of the to-be-compared external force by using a friction characteristic model representing a relationship between a slip between the wheel of the vehicle and the road surface and a road surface reaction force, an estimated value of the friction coefficient which has been already determined, and an observed value of a predetermined type of a quantity to be observed, which is related to a behavior of the vehicle; a second estimating element of the to-be-compared external force which
finds a value of an external force component balancing out an inertial force on the basis of an observed value of a motion state quantity of the vehicle that defines the inertial force, which is a part of an inertial force generated by a motion of the vehicle and corresponds to the to-be-compared external force, andobtains the found value of the external force component as a second estimated value of the to-be-compared external force; a first friction coefficient increasing/decreasing manipulated variable determining element and a second friction coefficient increasing/decreasing manipulated variable determining element, each of which determines an increasing/decreasing manipulated variable of an estimated value of the friction coefficient of the road surface on the basis of at least the first estimated value and the second estimated value; and a friction coefficient estimated value updating element which determines a new estimated value of the friction coefficient by updating the estimated value of the friction coefficient of the road surface on the basis of at least any one of the increasing/decreasing manipulated variables, which have been determined by the first friction coefficient increasing/decreasing manipulated variable determining element and the second friction coefficient increasing/decreasing manipulated variable determining element, respectively, wherein: the first friction coefficient increasing/decreasing manipulated variable determining element comprises a (1—1)th filter and the second friction coefficient increasing/decreasing manipulated variable determining element comprises a (2—1)th filter; the second friction coefficient increasing/decreasing manipulated variable determining element determines the increasing/decreasing manipulated variable on the basis of at least a deviation between the first estimated value and the second estimated value such that the deviation therebetween is converged to zero; and the first friction coefficient increasing/decreasing manipulated variable determining element determines the increasing/decreasing manipulated variable on the basis of at least a deviation between a (1—1)th estimated filtering value obtained by passing the first estimated value through the (1—1)th filter for frequency component adjustment and a (2—1)th estimated filtering value obtained by passing the second estimated value through the (2—1)th filter for frequency component adjustment having the same frequency characteristic as the (1—1)th filter, such that the deviation is converged to zero. |
