Method and apparatus for controlling ride height of a wheeled vehicle

• US 6,293,562 B1
• Filed: 11/18/1999
• Issued: 09/25/2001
• Est. Priority Date: 11/18/1998
• Status: Expired due to Fees

• Current Assignee: Daimler Chrysler Company LLC (Stellantis NV)
• Original Assignee: Daimler Chrysler Company LLC (Stellantis NV)
• Inventors: Kutscher, Eberhard
• Primary Examiner(s): Dickson, Paul N.
• Assistant Examiner(s): Draper, Deanne
• Application Number:
  US09/442,743
• Time in Patent Office: 677 Days
• Field of Search: 280/6.159, 280/5.5, 280/5.514, 280/6.157, 280/6.15, 340/442, 340/443
• US Class Current: 280/6.159
• 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 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/252 vertical
• CPC Class Codes: B60G 2400/52 in tyre
• CPC Class Codes: B60G 2500/2012 Open systems
• CPC Class Codes: B60G 2500/30 Height or ground clearance
• CPC Class Codes: B60G 2800/164 Heaving; Squatting

Abstract

In a method for controlling the ride height of a wheeled vehicle, the distance between a vehicle body and a wheel suspension unit for at least one wheel provided with a gas-filled tire is adjusted to a distance setpoint value which can be predefined in a variable fashion at least as a function of the vehicle payload. The tire pressure is sensed and the distance setpoint value is additionally predefined in a variable fashion as a function of the sensed tire pressure. For this purpose, in the wheeled vehicle, the tire is assigned a tire-pressure sensor, and the distance setpoint value can additionally be predefined in a variable fashion as a function of the sensed tire pressure.

Claims

1. A method for controlling ride height in a wheeled vehicle, in which a distance between a vehicle body and a wheel suspension unit for at least one wheel having a gas-filled tire is adjusted to a distance setpoint value which is variable at least as a function of the vehicle payload, said method comprising:

sensing tire pressure of the at least one wheel; and

adjusting the distance setpoint value as a function of the sensed tire pressure.

2. The method according to claim 1, wherein the distance setpoint value is determined as a difference between a predetermined constant distance between the vehicle body and an underlying vehicle supporting surface, and an axle height correction value determined as a function of vehicle payload and tire pressure, using a predefined characteristic curve.

3. The method according to claim 2, wherein the axle height correction value is determined as a sum of at least one tire-pressure-specific correction component and a payload-specific correction component, said payload-specific correction component being determined from the measured load of a spring element which supports the vehicle body against a wheel suspension unit.

4. The method according to claim 1, wherein the distance setpoint value varies also as a function of a sensed travel velocity or wheel rotational speed.

5. A wheeled vehicle having a vehicle body supported by a spring element on a wheel suspension unit on which a wheel with a gas-filled tire is mounted, and a ride-height control system, which adjusts a distance between the vehicle body and the wheel suspension unit to a distance setpoint value which can be varied as a function of vehicle payload, wherein:

a tire-pressure sensor is assigned to the tire; and

the distance setpoint value can also be varied as a function of the sensed tire pressure.

6. The wheeled vehicle according to claim 5, wherein the ride-height control system determines the distance setpoint value as a difference between a predetermined constant distance, between the vehicle body and an underlying vehicle supporting surface, and an axle height correction value determined as a function of the vehicle payload and the tire pressure, using predefinable characteristic curves.

7. The wheeled vehicle according to claim 6, wherein the axle height correction value is a sum at least of a tire-pressure-specific correction component and a payload-specific correction component, the latter being derived from a load of a vehicle supporting spring element.

8. The wheeled vehicle according to claim 5, further comprising a velocity sensor assigned to the wheeled vehicle, wherein the distance setpoint value can additionally be varied as a function of sensed velocity.

9. The wheeled vehicle according to claim 5, wherein:

the vehicle body is supported, by a plurality of hydraulic or pneumatic spring elements on respective wheel suspension units, each of which has mounted thereon a wheel which is provided with a gas-filled tire;

the ride-height control system has a central, hydraulic or pneumatic pressure supply system for the spring elements with a pressure sensor a compressor unit and a valve block which can be actuated by a central regulator unit; and

the spring elements can be coupled individually to the compressor unit and the pressure sensor via the valve block.

10. A ride height control system for a vehicle having a vehicle body supported by a spring element on a wheel suspension unit with a wheel and a gas filled tire mounted thereon, said ride height control system comprising:

a pneumatically or hydraulically actuated device which adjusts a distance between the vehicle body and the wheel suspension unit to a distance setpoint value which can be varied as a function of vehicle payload; and

a tire pressure sensor assigned to the tire;

wherein the distance setpoint value also varies as a function of sensed tire pressure.