Vehicle roll sensing using load shift estimation

• US 20050049778A1
• Filed: 07/21/2004
• Published: 03/03/2005
• Est. Priority Date: 07/22/2003
• Status: Active Grant

• Current Assignee: Advics Company Limited (Aisin Corp.), Toyoda Koki Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Advics Company Limited (Aisin Corp.), Toyoda Koki Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Yasui, Yoshiyuki, Kato, Hiroaki, Ono, Eiichi, Niino, Hiroaki, Muragishi, Yuji, Momiyama, Minekazu, Aizawa, Hiroaki
• Granted Patent: US 7,164,974 B2
• Time in Patent Office: Days
• US Class Current: 701/124
• CPC Class Codes: B60R 16/0233 Vehicle tilting, overturning or roll over
• CPC Class Codes: B60T 2230/03 Overturn, rollover
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: B60W 2040/1307 Load distribution on each wheel suspension
• CPC Class Codes: B60W 2040/1315 Location of the centre of gravity
• CPC Class Codes: B60W 2520/30 Wheel torque
• CPC Class Codes: B60W 40/11 Pitch movement
• CPC Class Codes: B60W 40/112 Roll movement
• CPC Class Codes: B60W 40/114 Yaw movement
• CPC Class Codes: B60W 40/12 related to parameters of the vehicle itself , e.g. tyre models

Abstract

In vehicle roll sensing of the present invention, a self-aligning torque (SAT) estimator estimates a composite value of SATs generated on tire contact patch of right and left wheels. A slip angle computer detects a vehicle speed and a steering angle and computes a slip angle of the wheel from the measured vehicle speed and steering angle. An SAT model value computer estimates an SAT model value as a composite value of SATs of the right and left wheels when no load shifts between the right and left wheels on the basis of the slip angle. A load shift ratio estimator estimates a load shift state of the right and left wheels on the basis of the composite value of the SATs of the wheels and the SAT model value. A vehicle rollover estimator estimates a rollover of the vehicle on the basis of the estimated load-shift state.

Claims

1. An apparatus for estimating a load shift state in wheels, comprising:

a self-aligning torque composite value estimating/detecting unit which estimates or detects a composite value of self-aligning torques generated on tire contact patch of right and left wheels;

a self-aligning torque model value computing unit which computes a self-aligning torque model value as a composite value of self-aligning torques of the right and left wheels when no load shift exists between the right and left wheels; and

a load shift state estimating unit which estimates a load shift state of the right and left wheels on the basis of the composite value of the self-aligning torques estimated or detected by the self-aligning torque estimating/detecting unit and the self-aligning torque model value computed by the self-aligning torque model value computing unit.

2. The apparatus of claim 1, further comprising a slip angle estimating unit for estimating a slip angle of the wheel, wherein the self-aligning torque model value computing unit estimates the self-aligning torque model value on the basis of the slip angle estimated by the slip angle estimating unit.

3. An apparatus for estimating a roll state of a vehicle, comprising:

a self-aligning torque composite value estimating/detecting unit which estimates or detects a composite value of self-aligning torques generated on tire contact patch of right and left wheels;

a self-aligning torque model value computing unit which computes a self-aligning torque model value as a composite value of self-aligning torques of the right and left wheels when no load shift exists between the right and left wheels;

a load shift state estimating unit which estimates a load shift state of the right and left wheels on the basis of the composite value of the self-aligning torques estimated or detected by the self-aligning torque estimating/detecting unit and the self-aligning torque model value computed by the self-aligning model value computing unit; and

a roll state estimating unit which estimates a roll state of the vehicle on the basis of the load shift state estimated by the load shift state estimating unit.

4. The apparatus of claim 3, wherein the roll state estimating unit estimates a rollover of the vehicle as the roll state of the vehicle.

5. The apparatus of claim 3, wherein the roll state estimating unit estimates a roll state of the vehicle on the basis of a change state of the load shift state estimated by the load shift state estimating unit and the load shift state.

6. A method of estimating a load shift state between a set of wheels of a vehicle, comprising:

determining a composite value of self-aligning torques generated on tire contact patch of a set of wheels;

computing a self-aligning torque model value as a composite value of the self-aligning torques of the wheels when no load shifts between the wheels; and

estimating the load shift state of the wheels on the basis of the composite value of the self-aligning torques and the self aligning torque model value.

7. The method of claim 6, further comprising estimating a slip angle of the wheel, wherein computation of the self aligning torque model value is estimation of the self-aligning torque model value on the basis of the slip angle estimated.

8. The method of claim 6, further comprising estimating a roll state of the vehicle on the basis of the load shift state.

9. The method of claim 8, wherein the estimation of the roll state of the vehicle includes estimation of a rollover of the vehicle from the roll state of the vehicle.

10. The method of claim 8, wherein the estimation of the roll state includes estimation of a roll state of the vehicle on the basis of a change state of the load shift state and the load shift state.

11. The method of claim 6, wherein the determination of the self-aligning torque composite value includes estimation of the composite value.

12. The method of claim 6, wherein the determination of the self-aligning torque composite value includes detection of the composite value.

13. The method of claim 6, wherein the estimation of the load shift state of the wheels includes calculation of a load shift ratio of the wheels.

14. The method of claim 13, wherein the estimation of the load shift state of the wheels further includes calculation of a change velocity of the load shift ratio.