Apparatus and method for automatically leveling an object

• US 7,226,057 B2
• Filed: 05/11/2004
• Issued: 06/05/2007
• Est. Priority Date: 03/10/2000
• Status: Expired due to Term

• Current Assignee: Days Corporation
• Original Assignee: Days Corporation
• Inventors: Sproatt, James N., Eichhorn, Mark M., Rouch, James E., Poseley, Alice E.
• Primary Examiner(s): CULBRETH, ERIC D
• Application Number:
  US10/843,128
• Publication Number:
  US 20040256815A1
• Time in Patent Office: 1,120 Days
• Field of Search: 280/6.153, 280/6.154, 280/6.15, 280/5.514, 280/5.507
• US Class Current: 280/6.153
• CPC Class Codes: B60S 9/12 of telescopic type

Abstract

A method and apparatus for automatically leveling a vehicle is provided, employing air springs, a sensor and a controller. The air springs are each mounted to the vehicle, and each can be at least partially inflated to provide suspension for the vehicle. Each of the air springs can also level the vehicle when the vehicle is parked. The sensor is mounted to the vehicle to sense pitch and roll of the vehicle relative to a reference level plane. The sensor also produces an orientation signal representing the vehicle pitch and roll. In response to the signal, the controller may cause at least one of the air springs to either inflate to move the vehicle upwardly, or deflate to move the vehicle downwardly relative to a ground surface, until the orientation of the vehicle reaches the reference level plane within a tolerance.

Claims

1. An apparatus for leveling a vehicle having an air suspension system which comprises an independently adjustable right front suspension assembly, left front suspension assembly, right rear suspension assembly, and left rear suspension assembly mounted to the vehicle, the apparatus for leveling a vehicle comprising, a sensor mounted to the vehicle to sense pitch and roll of the vehicle relative to a reference level plane, the sensor producing an orientation signal representing the vehicle pitch and roll;

a controller coupled to the air suspension system and the sensor, wherein the controller, in response to an operator command, levels the vehicle relative to the reference level plane by sequentially actuating the suspension assemblies, wherein the controller interprets the orientation signal to determine an end and a side of the vehicle which are below the reference level plane, then alternating between adjusting the end and the side upwardly by sequentially supplying air to the suspension assemblies at the end and sequentially supplying air to the suspension assemblies at the side, each suspension assembly being inflated for a first predetermined period of time during each upward adjustment, and wherein the controller includes a memory for storing data corresponding to the reference level plane and is configured to write data representing an orientation signal to the memory to replace the reference level plane data with orientation signal data.

2. The apparatus of claim 1, wherein the sensor provides the orientation signal to the controller indicating a change in the vehicle orientation when the vehicle is at rest.

3. The apparatus of claim 1, wherein the controller interprets the orientation signal after each adjustment to determine whether either the end or the side has passed through the reference level plane.

4. The apparatus of claim 3, wherein upon determining that one of the ends or the side has passed through the reference level plane, the controller alternates between adjusting the one end or side downwardly by sequentially deflating the suspension assemblies at the one end or side for a second predetermined period of time which is less than the first predetermined period of time, and continuing to adjust the other end or side upwardly by sequentially inflating the suspension assemblies at the other end or side for the first predetermined period of time.

5. The apparatus of claim 4, wherein the controller changes the direction of adjustment of the end and the side each time the end and the side pass through the reference level plane as indicated by the orientation signal and reduces the period of time for inflating or deflating the suspension assemblies at the end and the side with each passing of the reference level plane.

6. The apparatus of claim 1, further comprising switches for individually actuating the suspension assemblies.

7. The apparatus of claim 1, further comprising a valve assembly that allows deflating and inflating of at least one of the suspension assemblies.

8. The apparatus of claim 7, wherein a valve assembly is provided for each suspension assembly.

9. The apparatus of claim 7, wherein air can be selectively added to or exhausted from at least one of the suspension assemblies through the valve assembly.

10. The apparatus of claim 9, wherein the controller blocks the ability of at least one of the suspension assemblies to provide suspension to the vehicle when the vehicle is at rest.

11. The apparatus of claim 10, wherein the controller initiates the leveling of the vehicle by inflating or deflating at least one of the suspension assemblies after its ability to provide suspension to the vehicle is blocked.

12. The apparatus of claim 7, wherein, during leveling of the vehicle, air can be added to or subtracted from air already present in the suspension assemblies prior to leveling the vehicle.

13. A method for automatically leveling a vehicle having four adjustable air springs mounted to a suspension system on the vehicle at each of the respective corners of the vehicle, each spring being inflatable and deflatable, a sensor mounted to the vehicle to sense the pitch and roll of the vehicle and provide an orientation signal representing the vehicle pitch and roll, and a controller coupled to the springs and the sensor for responding to the vehicle orientation signal by inflating or deflating the springs to adjust the vehicle orientation so it approaches a reference level plane stored as data within the controller, the method comprising the steps of:

blocking air suspension control to the springs;

comparing the orientation signal produced by the sensor;

determining a low end and a low side of the vehicle, relative to the reference level plane; and

alternating between sequentially inflating at least one of the springs at the low end of the vehicle for a first predetermined actuation period, and sequentially inflating at least one of the springs at the low side of the vehicle for a second predetermined actuation period which is the same as the first predetermined actuation period, determining whether the low end of the vehicle has been moved through the reference level plane after each sequential inflation of the springs at the low end of the vehicle, reversing direction of adjustment of the springs at the low end of the vehicle each time the low end of the vehicle is moved through the reference level plane, reducing the first predetermined actuation period each time the direction of adjustment of the springs at the low end of the vehicle is reversed, determining whether the low side of the vehicle has been moved through the reference level plane after each sequential inflation of the springs at the low side of the vehicle, reversing the direction of adjustment of the springs at the low side of the vehicle each time the low side of the vehicle is moved through the reference level plane, reducing the second predetermined actuation period each time the direction of adjustment of the springs at the low side of the vehicle is reversed, comparing the first and second predetermined actuation period to a preset minimum actuation period and stopping the automatic leveling process when either the first or the second predetermined actuation period is less than the preset minimum actuation period.

14. The method of claim 13, further comprising the step of further inflating each spring until it lifts its respective corner of the vehicle sufficiently that the orientation signal indicates a change in vehicle orientation.

15. The method of claim 13, further comprising the step of stopping the automatic leveling when the orientation signal represents a vehicle orientation which is within a specified tolerance of the reference level plane.

16. An apparatus for automatically leveling a vehicle having four corners, the apparatus comprising:

an adjustable air spring mounted to the vehicle adjacent the left front corner of the vehicle;

an adjustable air spring mounted to the vehicle adjacent the right front corner of the vehicle;

an adjustable air spring mounted to the vehicle adjacent the left rear corner of the vehicle;

an adjustable air spring mounted to the vehicle adjacent the right rear corner of the vehicle;

a level sensor mounted to the vehicle for sensing the pitch and roll orientation of the vehicle relative to horizontal, the level sensor outputting an orientation signal representing the pitch and roll of the vehicle;

a controller connected to the adjustable air springs and the level sensor, the controller including a memory for storing data representing a reference level plane and outputs coupled to the adjustable air springs for inflating and deflating the air springs, the controller comparing the orientation signal to the reference level plane to determine whether the front or rear of the vehicle is above the reference level plane and whether the left or right side of the vehicle is below the reference level plane, the controller being responsive to an operator input to level the vehicle by alternating between sequential adjustments of the air springs at the front or rear of the vehicle which is above the reference level plane and sequentially deflating at least one of the air springs at the left or right side of the vehicle which is above the reference level plane;

wherein the controller actuates each air spring for a first predetermined period of time during each adjustment until the orientation signal indicates that the front, rear, left side, or right side of the vehicle has passed through the reference level plane and wherein the controller inflates the air springs corresponding to the front, rear, left side, or right side of the vehicle which has passed through the reference level plane for a second predetermined period of time which is less than the first predetermined period of time.