Vehicle stability control system

• US 20060052908A1
• Filed: 08/30/2005
• Published: 03/09/2006
• Est. Priority Date: 09/06/2004
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Sawada, Mamoru, Matsumoto, Toshiki
• Granted Patent: US 7,599,763 B2
• Time in Patent Office: Days
• US Class Current: 701/1
• CPC Class Codes: B60G 2800/014 Pitch; Nose dive
• CPC Class Codes: B60G 2800/213 by applying forward/backward torque on each wheel individually
• CPC Class Codes: B60G 2800/952 Electronic driving torque distribution
• CPC Class Codes: B60W 2050/0017 Modal analysis, e.g. for determining system stability
• CPC Class Codes: B60W 2050/0028 Mathematical models, e.g. for simulation
• CPC Class Codes: B60W 2050/0031 Mathematical model of the vehicle
• CPC Class Codes: B60W 2520/16 Pitch
• CPC Class Codes: B60W 2520/28 Wheel speed
• CPC Class Codes: B60W 2530/16 Driving resistance
• CPC Class Codes: B60W 2530/20 Tyre data
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2710/0666 Engine torque
• CPC Class Codes: B60W 2710/105 Output torque
• CPC Class Codes: B60W 2720/16 Pitch
• CPC Class Codes: B60W 2720/30 Wheel torque
• CPC Class Codes: B60W 30/045 Improving turning performance
• CPC Class Codes: B60W 30/18009 related to particular drive situations
• CPC Class Codes: B60W 30/18145 Cornering

Abstract

A vehicle stability control system includes a base required driving force calculation unit, an estimated driving force estimation unit, and a required driving force correction unit. The base required driving force calculation unit calculates a physical quantity to generate the base required driving force at a driving wheel. The estimated driving force estimation unit estimates a driving force as being generated in the vehicle. The required driving force correction unit obtains a correction to suppress a potential pitching vibration in the vehicle. The physical quantity calculated by the base required driving force calculation unit is corrected on the basis of the correction. The corrected required driving force obtained by the required driving force correction unit is generated at the driving wheel.

Claims

1. A vehicle stability control system comprising:

a base required driving force calculation unit that calculates a physical quantity corresponding to a base required driving force desired by a driver to generate the base required driving force at a driving wheel of a vehicle;

an estimated driving force estimation unit that obtains a physical quantity corresponding to an estimated driving force that is estimated as being generated in the vehicle; and

a required driving force correction unit that obtains a corrected required driving force in such a way that a pitching vibration possibly occurring in the vehicle when the estimated driving force is generated is obtained on the basis of the physical quantity corresponding to the estimated driving force, a correction to suppress the pitching vibration is obtained, and the physical quantity corresponding to the base required driving force calculated by the base required driving force calculation unit is corrected on the basis of the correction,

wherein the corrected required driving force obtained by the required driving force correction unit is generated at the driving wheel.

2. The vehicle stability control system according to claim 1, wherein the required driving force correction unit has an equation of state describing state quantities of the vehicle on the basis of an on-spring body model of the vehicle and also an output equation describing the pitching vibration with respect to the state quantities on the basis of the equation of state, and the physical quantity corresponding to the base required driving force is corrected so as to suppress the fluctuation of the pitching vibration obtained from the output equation and the state quantities.

7. The vehicle stability control system according to claim 1, wherein the base required driving force calculation unit obtains a base required engine torque or a base required output axle torque as a physical quantity corresponding to the base required driving force.

8. The vehicle stability control system according to claim 1, further comprising a running resistance disturbance estimation unit that estimates a running resistance disturbance applied to a wheel of the vehicle,

wherein the required driving force correction unit estimates that a value obtained by adding a running resistance disturbance estimated by the running resistance disturbance estimation unit to a physical quantity corresponding to the estimated driving force obtained by the estimated driving force calculation unit is a currently generated driving force, and a correction is obtained as the one used when a driving force, in which this running resistance disturbance is taken into consideration, is generated.

3. A vehicle stability control system comprising:

a base required driving force calculation unit that calculates a physical quantity corresponding to a base required driving force desired by a driver to generate the base required driving force at a driving wheel of a vehicle;

an estimated driving force estimation unit that obtains a physical quantity corresponding to an estimated driving force that is estimated as being generated in the vehicle; and

a required driving force correction unit that obtains a corrected required driving force in such a way that a fluctuation of a front or rear wheel contact load possibly occurring in the vehicle when the estimated driving force is generated is obtained on the basis of the physical quantity corresponding to the estimated driving force, a correction to reduce a derivative term of the fluctuation of the front or rear wheel contact load is obtained, and the physical quantity corresponding to the base required driving force calculated by the base required driving force calculation unit is corrected on the basis of the correction,

wherein the corrected required driving force obtained by the required driving force correction unit is generated at the driving wheel.

4. The vehicle stability control system according to claim 3, wherein the required driving force correction unit has an equation of state describing state quantities of the vehicle on the basis of an on-spring body model of the vehicle and an output equation describing the derivative term of the fluctuation of the front or rear wheel contact load with the state quantities on the basis of the equation of state, and the physical quantity corresponding to the base required driving force is corrected so as to reduce the derivative term of the fluctuation of the front or rear wheel contact load obtained from the output equation and the state quantities.

5. A vehicle stability control system comprising:

a base required driving force calculation unit that calculates a physical quantity corresponding to a base required driving force desired by a driver to generate the base required driving force at a driving wheel of a vehicle;

an estimated driving force estimation unit that obtains a physical quantity corresponding to an estimated driving force that is estimated to be being generated in the vehicle; and

a required driving force correction unit that obtains a corrected required driving force in such a way that a vertical motion of the vehicle body possibly occurring in the vehicle when the estimated driving force is generated is obtained on the basis of the physical quantity corresponding to the estimated driving force, a correction to suppress the fluctuation of the vertical motion of the vehicle body is obtained, and the physical quantity corresponding to the base required driving force calculated by the base required driving force calculation unit is corrected on the basis of the correction;

wherein the corrected required driving force obtained by the required driving force correction unit is generated at the driving wheel.

6. The vehicle stability control system according to claim 5, wherein the required driving force correction unit has an equation of state describing state quantities of the vehicle on the basis of an on-spring body model of the vehicle and an output equation describing the vertical motion of the vehicle body with the state quantities on the basis of the equation of state, and the physical quantity corresponding to the base required driving force is corrected so as to suppress the vertical motion of the vehicle body obtained from the output equation and the state quantities.