Height determination for two independently suspended wheels using a height sensor for only one wheel

• US 9,452,657 B1
• Filed: 12/22/2015
• Issued: 09/27/2016
• Est. Priority Date: 12/22/2015
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Giaier, Kevin S., Anderson, Edmund S.
• Primary Examiner(s): Freedman, Laura
• Application Number:
  US14/978,098
• Time in Patent Office: 280 Days
• US Class Current: 1/1
• CPC Class Codes: B60G 17/01908 Acceleration or inclination sensors characterised by the use of gyroscopes B60G21/08
• CPC Class Codes: B60G 17/01941 characterised by the use of piezoelectric elements, e.g. sensors or actuators
• CPC Class Codes: B60G 21/055 Stabiliser bars
• CPC Class Codes: B60G 2400/252 vertical
• CPC Class Codes: B60G 2400/842 Temperature
• CPC Class Codes: B60G 2401/12 Strain gauge
• CPC Class Codes: B60G 2500/30 Height or ground clearance
• CPC Class Codes: B60Q 1/08 automatically
• CPC Class Codes: B60Q 1/10 due to vehicle inclination, e.g. due to load distribution
• CPC Class Codes: B60Q 2300/136 Roll

Abstract

Ride height for use in an adaptive suspension damping system, tiltable headlamp systems, or other systems is determined for first and second wheels which are mounted to first and second suspensions having first and second control arms coupled between the respective wheels and a frame of the vehicle. An anti-roll system is coupled between the control arms. A mechanical height sensor is coupled to the first wheel to directly sense a first height associated with the first wheel. A strain sensor is coupled to the anti-roll system to generate a strain signal in response to a strain in the anti-roll system. A controller converts the strain signal to a second height associated with the second wheel. Thus, ride heights for both wheels on opposite sides of the vehicle are obtained using only one direct height measurement.

Claims

1. A vehicle comprising:

first and second wheels;

first and second suspensions including first and second control arms coupled between the respective wheels and a frame of the vehicle;

an anti-roll system coupled between the control arms;

a height sensor coupled to the first wheel sensing a first height associated with the first wheel;

a strain sensor coupled to the anti-roll system generating a strain signal in response to a strain in the anti-roll system; and

a controller converting the strain signal to a second height associated with the second wheel.

2. The vehicle of claim 1 wherein the controller determines a height difference from the strain signal, and determines the second height by summing the first height and the height difference.

3. The vehicle of claim 2 wherein the controller uses a lookup table relating the strain signal to the height difference.

4. The vehicle of claim 2 wherein the controller uses a lookup table relating the strain signal to a force acting on the anti-roll system, and wherein the controller determines the height difference in response to the force.

5. The vehicle of claim 1 wherein the anti-roll system is comprised of an anti-roll bar, and wherein the strain sensor is mounted to the anti-roll bar to respond to torsion.

6. The vehicle of claim 1 wherein the anti-roll system is comprised of an anti-roll bar having an end link connected to a control arm, and wherein the strain sensor is mounted to the end link to respond to compression and tension.

7. The vehicle of claim 1 wherein the strain sensor is mounted to the anti-roll system by an adhesive, and wherein the strain sensor further comprises a protective coating.

8. The vehicle of claim 1 further comprising:

a continuously controlled damping system coupled to the wheels, wherein the damping system actively varies a damping characteristic in response to the first and second heights.

9. The vehicle of claim 1 further comprising:

an adaptive headlamp system including tiltable headlamps, wherein the headlamps are aimed in response to the first and second heights.

10. A vehicle comprising:

two wheels;

independent suspensions for the wheels including respective control arms;

a stabilizer system coupled between the control arms;

a height sensor coupled to one wheel sensing an associated first height;

a strain sensor coupled to the stabilizer system generating a strain signal in response to a strain in the stabilizer system; and

a controller converting the strain signal to a second height associated with the other wheel.

11. A method comprising:

directly measuring a first displacement in a suspension for a first wheel on a vehicle;

measuring a strain occurring in an anti-roll system coupled between the first wheel and a second wheel;

converting the strain to a height difference between the first wheel and the second wheel; and

summing the height difference and the first displacement to determine a second displacement for the second wheel.

12. The method of claim 11 further comprising:

adaptively controlling an active damping system coupled to the wheels in response to the first and second displacements.

13. The method of claim 11 further comprising:

adaptively controlling an active headlamp system for aiming at least one headlamp in response to the first and second displacements.

14. The method of claim 11 wherein the step of converting the strain to a height difference is comprised of:

using a strain voltage from a strain detector as an index into a lookup table relating the strain voltage to the height difference.

15. The method of claim 11 wherein the step of converting the strain to a height difference is comprised of:

using a strain voltage from a strain detector as an index into a lookup table relating the strain voltage to a force acting on the anti-roll system; and

determining the height difference in response to the force and a model correlating the force to corresponding height differences.

16. The method of claim 11 wherein the step of measuring a strain occurring in the anti-roll system is comprised of sensing a compression and a tension occurring in a link connecting an anti-roll bar of the anti-roll system to a control arm of the suspension.

17. The method of claim 11 wherein the step of measuring a strain occurring in the anti-roll system is comprised of sensing a torsion occurring in an anti-roll bar of the anti-roll system.