Encoded electromagnetic based ride height sensing

• US 9,925,840 B2
• Filed: 04/04/2016
• Issued: 03/27/2018
• Est. Priority Date: 04/04/2016
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: D'Amato, Anthony Mario, Samuels, Harold Bernard, Pfeiffer, John Jeffrey
• Primary Examiner(s): Paige, Tyler D
• Application Number:
  US15/090,244
• Publication Number:
  US 20170282665A1
• Time in Patent Office: 722 Days
• Field of Search: 701 37
• CPC Class Codes: B60G 17/016 characterised by their responsiveness, when the vehicle is travelling, to specific motion, a specific condition, or driver input B60G17/017 takes precedence
• CPC Class Codes: B60G 2204/62 Adjustable continuously, e.g. during driving
• CPC Class Codes: B60G 2400/25 Stroke; Height; Displacement
• CPC Class Codes: B60G 2401/172 Hall effect
• CPC Class Codes: B60G 2500/30 Height or ground clearance
• CPC Class Codes: B60G 2600/182 Active control means
• CPC Class Codes: B60G 2600/187 Digital Controller Details and Signal Treatment
• CPC Class Codes: G01D 5/142 using Hall-effect devices measuring magnetic variables using Hall-effect or other galvanomagnetic devices G01R33/06

Abstract

Various embodiments of the present disclosure provide a ride height sensing system that includes an encoded electromagnetic source as an input unit for a Hall Effect sensors and the signal from the electromagnet is encoded to enable the rejection of ambient magnetic field. In various embodiments of the present disclosure, a band pass filter is used for signal processing of the encoded electromagnetic data. Additionally, several Hall Effect sensors may be used with a single electromagnetic source to provide multi-axis sensing and as such, provides robustness in determining ride height changes, or in the case of dependent suspensions (solid axle), a single electromagnetic source can used to determine ride height at multiple locations on the axle.

Claims

1. A vehicle having a ride height sensing system comprising:

an electromagnetic source configured to produce a magnetic field at a specified frequency;

a magnetometer configured to measure a strength of the magnetic field; and

a controller configured to filter measurements of the magnetometer at the specified frequency to extract variance in the strength of the magnetic field associated with the electromagnetic source and determine a change in ride height of a vehicle body.

2. The vehicle having the ride height sensing system of claim 1, wherein the magnetometer is a hall effect based sensor.

3. The vehicle having the ride height sensing system of claim 2, wherein the hall effect based sensor is capable of sensing a multi-axis magnetic field.

4. The vehicle having the ride height sensing system of claim 1, wherein the controller utilizes the filtered measurements to determine physical distance units for ride height measurements.

5. The vehicle having the ride height sensing system of claim 4, wherein the controller utilizes the determined physical distance units to obtain desired ride height distance measurements directly from the measurements by the magnetometer.

6. The vehicle having the ride height sensing system of claim 1, wherein the electromagnetic source is capable of high switching rates.

7. The vehicle having the ride height sensing system of claim 1, wherein the extraction of the variance in the strength of the magnetic field associated with the electromagnetic source is a real-time extraction.

8. The vehicle having the ride height sensing system of claim 1, wherein the controller utilizes the determined ride height to activate an active suspension system of the vehicle.

9. The vehicle having the ride height sensing system of claim 1, wherein the controller is configured to determine a frequency of the electromagnetic source.

10. The vehicle having the ride height sensing system of claim 1, wherein the controller is configured to decompose a multi-axes reading for magnetic field data regarding each axis.

12. The ride height sensing method for the vehicle of claim 1, wherein the magnetometer is a hall effect based sensor.

13. The ride height sensing method for the vehicle of claim 12, wherein the hall effect based sensor is capable of sensing a multi-axis magnetic field.

11. A ride height sensing method for a vehicle comprising:

configuring an electromagnetic source of the vehicle to produce a magnetic field signal at a specified frequency

receiving, from a magnetometer of the vehicle, measurements of a magnetic field;

filtering the measurements to extract variances of strength of the magnetic field associated with the specified frequency; and

determining a change in ride height of a vehicle body based on the variances of the strength of the magnetic field.

14. The ride height sensing method for the vehicle of claim 11, further comprising utilizing, by a controller, the measurements to determine physical distance units for ride height measurements.

15. The ride height sensing method for the vehicle of claim 14, further comprising utilizing, by the controller, the determined physical distance units to obtain desired ride height distance measurements directly from the variances of the strength of the magnetic field measured by the magnetometer.

16. The ride height sensing method for the vehicle of claim 11, wherein the electromagnetic source is capable of high switching rates.

17. The ride height sensing method for the vehicle of claim 11, wherein the extraction of the variances of the strength of the magnetic field associated with the specified frequency is a real-time extraction.

18. The ride height sensing method for the vehicle of claim 11, further comprising utilizing, by a controller, the determined ride height to activate an active suspension system of the vehicle.

19. The ride height sensing method for the vehicle of claim 11, further comprising configuring a controller to determine a frequency of the electromagnetic source.

20. A vehicle comprising:

a first electromagnetic source associated with a first axis of the vehicle configured to produce a first magnetic field at a first frequency;

a second electromagnetic source associated with a second axis of the vehicle configured to produce a second magnetic field at a second frequency, the second frequency different from the first frequency;

a magnetometer configured to measure a total magnetic field proximate the vehicle;

a controller configured to;

filter, at the first and second frequencies, the measurement of the total magnetic field to determine a first variance in strength of the first magnetic field and a second variance in strength of the second magnetic field; and

determine a change in ride height of a body of the vehicle based on the variances of strength of the first and second magnetic fields.