Estimation device, vehicle, and estimation method

A vehicle including an estimation device that estimates a stroke quantity indicating a displacement in an up-and-down direction of the vehicle, in a multistage elastic member in which a plurality of members, each having a different load displacement characteristic indicating a relationship between a load and the displacement, are disposed, the estimation device comprising:

• a load calculation unit configured to calculate a variable ground contact load received by a wheel of the vehicle from a ground contact surface, based on a detection signal of a wheel speed sensor for detecting a wheel speed of the vehicle;
• a state quantity estimation unit configured to estimate the stroke quantity generated in the multistage elastic member, based on the multistage elastic member and the variable ground contact load, the multistage elastic member having a load displacement characteristic of any one of the plurality of members set as an initial value;
• and
• a characteristic change unit configured to change a setting of the initial value to an estimated load displacement characteristic, in a case where the estimated load displacement characteristic corresponding to the stroke quantity that is estimated by the state quantity estimation unit and the load displacement characteristic that is set as the initial value are different from each other,
• wherein the state quantity estimation unit corrects the stroke quantity, based on a result of an estimation operation in which the estimated load displacement characteristic that is changed by the characteristic change unit is set as a changed initial value.

An estimation method of an estimation device that estimates a stroke quantity indicating a displacement in an up-and-down direction of a vehicle, in a multistage elastic member in which a plurality of members, each having a different load displacement characteristic indicating a relationship between a load and the displacement, are disposed, the estimation method comprising:

• calculating, by a load calculation unit, a variable ground contact load received by a wheel of the vehicle from a ground contact surface, based on a detection signal of a wheel speed sensor for detecting a wheel speed of the vehicle;
• estimating, by a state quantity estimation unit, the stroke quantity generated in the multistage elastic member, based on the multistage elastic member and the variable ground contact load, the multistage elastic member having a load displacement characteristic of any one of the plurality of members set as an initial value;
• changing, by a characteristic change unit, a setting of the initial value to an estimated load displacement characteristic, in a case where the estimated load displacement characteristic corresponding to the stroke quantity that is estimated by the estimating and the load displacement characteristic that is set as the initial value are different from each other;
• and
• correcting, by the state quantity estimation unit, the stroke quantity, based on a result of an estimation operation in which the estimated load displacement characteristic that is changed by the changing is set as a changed initial value.