VEHICLE BODY ATTITUDE CONTROL APPARATUS

• US 20120029770A1
• Filed: 07/26/2011
• Published: 02/02/2012
• Est. Priority Date: 07/29/2010
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Inventors: HIRAO, Ryusuke, Yamakado, Makoto, Ichimaru, Nobuyuki
• Granted Patent: US 8,838,336 B2
• Time in Patent Office: Days
• US Class Current: 701/38
• CPC Class Codes: B60G 17/08 Characteristics of fluid dampers adjusting fluid dampers in general F16F9/44 - F16F9/53
• CPC Class Codes: B60G 2400/0511 Roll angle
• CPC Class Codes: B60G 2400/0521 Roll rate
• CPC Class Codes: B60G 2400/0522 Pitch rate
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/41 Steering angle
• CPC Class Codes: B60G 2500/10 Damping action or damper

Abstract

The present invention provides a vehicle body attitude control apparatus capable of improvement of cornering operability, steering stability, and a ride comfort while a vehicle is running. A controller includes a gain, a determination unit, a multiplication unit, an FF control unit, a difference calculation unit, an FB control unit, an average value calculation unit, a target damping force calculation unit, and a damper instruction value calculation unit so as to enable such control that a pitch rate and a roll rate are set into a proportional relationship while the vehicle is cornering. The controller calculates a target pitch rate proportional to the roll rate, variably controls a damping force characteristic of a damping force variable damper disposed at each of front left, front right, rear left, and rear right wheels so as to achieve the target pitch rate, and generates a pitch moment to be applied to the vehicle body accordingly.

Claims

1. A vehicle body attitude control apparatus for controlling an attitude of a vehicle body of a vehicle, the apparatus comprising:

a target pitch state calculation unit configured to calculate a target pitch state as a target value of a pitch state of the vehicle body according to a roll state of the vehicle body; and

a pitch moment generation unit configured to generate a pith moment to be applied to the vehicle body so that the pitch state of the vehicle body approaches the target pitch state.

2. The vehicle body attitude control apparatus according to claim 1, wherein

the pitch state is a pitch rate and the roll state is roll rate, and

the target pitch state calculation unit calculates the target pitch rate so that a nosedive inclination of the vehicle body is increased according to the degree of the roll rate of the vehicle body.

3. The vehicle body attitude control apparatus according to claim 1, wherein the pitch moment generation unit includes a target pitch moment calculation unit configured to calculate a target pitch moment from the target pitch state with use of a vehicle model, and a pitch moment generation mechanism configured to generate a pitch moment so that the pitch moment of the vehicle body approaches the target pitch moment.

4. The vehicle body attitude control apparatus according to claim 2, wherein the pitch moment generation unit includes a target pitch moment calculation unit configured to calculate a target pitch moment from the target pitch state with use of a vehicle model, and a pitch moment generation mechanism configured to generate a pitch moment so that the pitch moment of the vehicle body approaches the target pitch moment.

5. The vehicle body attitude control apparatus according to claim 1, further comprising a pitch state detection unit configured to detect the pitch state of the vehicle body,

wherein the pitch moment generation unit generates a pitch moment to be applied to the vehicle body so as to reduce a difference between the detected pitch state and the target pitch state.

6. The vehicle body attitude control apparatus according to claim 2, further comprising a pitch state detection unit configured to detect the pitch state of the vehicle body,

wherein the pitch moment generation unit generates a pitch moment to be applied to the vehicle body so as to reduce a difference between the detected pitch state and the target pitch state.

7. The vehicle body attitude control apparatus according to claim 1, wherein the vehicle includes at least four wheels,

wherein the pitch moment generation unit includes a damping force adjustable shock absorber capable of adjusting a damping characteristic thereof, the shock absorber being disposed at each of the wheels, and

wherein the pitch moment generation units adjust the pitch moment to be applied to the vehicle body by adjusting the damping force characteristic.

8. The vehicle body attitude control apparatus according to claim 2, wherein the vehicle includes at least four wheels,

wherein the pitch moment generation unit includes a damping force adjustable shock absorber capable of adjusting a damping characteristic thereof, the shock absorber being disposed at each of the wheels, and

wherein the pitch moment generation units adjust the pitch moment to be applied to the vehicle body by adjusting the damping force characteristic.

9. The vehicle body attitude control apparatus according to claim 3, wherein the vehicle includes at least four wheels,

wherein the pitch moment generation unit includes a damping force adjustable shock absorber capable of adjusting a damping characteristic thereof, the shock absorber being disposed at each of the wheels, and

wherein the pitch moment generation units adjust the pitch moment to be applied to the vehicle body by adjusting the damping force characteristic.

10. The vehicle body attitude control apparatus according to claim 4, wherein the vehicle includes at least four wheels,

wherein the pitch moment generation unit includes a damping force adjustable shock absorber capable of adjusting a damping characteristic thereof, the shock absorber being disposed at each of the wheels, and

wherein the pitch moment generation units adjust the pitch moment to be applied to the vehicle body by adjusting the damping force characteristic.

11. The vehicle body attitude control apparatus according to claim 1, wherein the vehicle includes at least four wheels,

wherein the pitch moment generation unit includes an active suspension configured to apply a vertical force to the vehicle body and the wheel, the active suspension being disposed at each of the wheels, and

wherein the pitch moment generation unit applies the pitch moment to the vehicle body by adjusting the vertical force.

12. The vehicle body attitude control apparatus according to claim 2, wherein the vehicle includes at least four wheels,

wherein the pitch moment generation unit includes an active suspension configured to apply a vertical force to the vehicle body and the wheel, the active suspension being disposed at each of the wheels, and

wherein the pitch moment generation unit applies the pitch moment to the vehicle body by adjusting the vertical force.

13. The vehicle body attitude control apparatus according to claim 3, wherein the vehicle includes at least four wheels,

wherein the pitch moment generation unit includes an active suspension configured to apply a vertical force to the vehicle body and the wheel, the active suspension being disposed at each of the wheels, and

wherein the pitch moment generation unit applies the pitch moment to the vehicle body by adjusting the vertical force.

14. The vehicle body attitude control apparatus according to claim 4, wherein the vehicle includes at least four wheels,

wherein the pitch moment generation unit includes an active suspension configured to apply a vertical force to the vehicle body and the wheel, the active suspension being disposed at each of the wheels, and

wherein the pitch moment generation unit applies the pitch moment to the vehicle body by adjusting the vertical force.

15. The vehicle body attitude control apparatus according to claim 1, wherein the roll state of the vehicle body and the pitch state of the vehicle body are obtained from a steering angle and a vehicle speed.

16. The vehicle body attitude control apparatus according to claim 1, wherein the pitch state is a pitch rate.

17. The vehicle body attitude control apparatus according to claim 1, wherein the pitch state is a pitch angle.