Pneumatic vehicle stabilization system

• US 20070158920A1
• Filed: 01/11/2006
• Published: 07/12/2007
• Est. Priority Date: 01/11/2006
• Status: Active Grant

• Current Assignee: International Truck Intellectual Property Co. LLC (Volkswagen AG)
• Original Assignee: International Truck Intellectual Property Co. LLC (Volkswagen AG)
• Inventors: Delaney, Patrick
• Granted Patent: US 7,611,154 B2
• Time in Patent Office: Days
• US Class Current: 280/5.514
• CPC Class Codes: B60G 17/0195 characterised by the regulation being combined with other vehicle control systems conjoint control of vehicle sub-units including control of suspension systems B60W10/22
• CPC Class Codes: B60G 2800/20 Stationary vehicle
• CPC Class Codes: B60G 2800/85 System Prioritisation

Abstract

An electronic height control system for a vehicle chassis air suspension is modified to provide bimodal operation. In the second mode of operation the chassis air suspension system is maintain a stationary in a stable, level position to serve as a base for a mobile aerial lift unit installed on the vehicle. Operation of the suspension system in its stabilization and leveling mode is triggered by activation of a vehicle power take-off unit (“PTO”) used to position the aerial lift unit.

Claims

1. A suspension system for a vehicle providing multiple points of support for a sprung section of the vehicle, the suspension system comprising:

a plurality of independent, fluidically charged support members with at least a first member being located under the sprung section at each point of support;

fluid pressure control for each fluidicly charged support member;

a biaxial horizontal level sensor installed on the sprung section; and

a chassis level controller responsive to the biaxial horizontal level sensor for directing the fluid pressure control to adjust the pressure in at least a first of the plurality of independent, fluidicly charged support members to level the sprung section.

2. A suspension system in accord with claim 1, the suspension system further comprising:

a plurality of suspension extension sensors with one suspension extension sensor being located at each point of support for generating indication of extension or compression of the independent, fluidicly charged support members relative to a norm; and

the chassis level controller being connected to receive the generated indication, the chassis level controller being adapted for bimodal operation including one mode in which the chassis level controller is responsive to the plurality of suspension extension sensors for directing the fluid pressure control to adjust the pressure in the plurality of independent, fluidicly charged members to obtain equal extension of the independent, fluidicly charged support members and a second mode in which the pressure in the independent, fluidicly charged support members is adjusted to obtain sprung section leveling.

3. A suspension system in accord with claim 2, the suspension system further comprising:

a power take-off controller installed on the vehicle;

a communications channel connected between the level controller and the power take-off controller; and

the level controller being responsive to engagement of the power take-off controller for operating in its second mode for leveling the sprung section of the vehicle and responsive to disengagement of the power take-off controller for operating in its first mode for providing equalizing of extension of the independent, fluidicly charged support members.

4. A suspension system in accord with claim 3, the suspension system further comprising:

a plurality of actuators under the control of the power take-off controller;

the power take-off controller being adapted to report operation of the actuators over the communications channel; and

the level controller being further responsive to receipt of report of operations of the actuators for releveling the sprung section.

5. A suspension system in accord with claim 4, the suspension system further comprising:

the level controller being responsive in its first mode of operation to the suspension extension sensors to extension or compression of the suspension at any support point to a local limit for limiting operation of the power take-off controller relative to the actuators.

6. A suspension system in accord with claim 5, the suspension system further comprising:

the level controller being responsive to an attempt to place the power take-off controller into engagement for determining, ab initio, if the sprung section can be leveled in accord with its first mode of operation and if not, for preventing operation of the power take-off controller.

7. A suspension system in accord with claim 6, the suspension system further comprising:

the actuators being hydraulic actuators; and

a mobile lift unit installed on the sprung section for positioning by the hydraulic actuators.

8. A vehicle chassis comprising:

a plurality of air bags disposed to support the chassis from vehicle wheels;

a height controller having first and second modes of operation for independently controlling the air pressure in each of the air bags;

a level sensor installed on the vehicle chassis;

a plurality of suspension extension sensors installed between the vehicle wheels and the vehicle chassis; and

the height controller being coupled to the level sensor and to the suspension extension sensors to receive readings therefrom, the height controller being responsive in the first mode of operation to the level sensor and to the extension sensors for leveling the chassis by varying the pressure in selected ones of the plurality of air bags up to the limits of extension or compression of the plurality of air bags and being further responsive in a second mode of operation to the extension sensors for varying the pressure in selected ones of the plurality of air bags for maintaining the vehicle chassis at an even height relative to the vehicle wheels.

9. A vehicle chassis in accord with claim 8, further comprising:

a mobile aerial lift unit installed on the chassis;

a power take-off unit for positioning the mobile aerial lift unit;

a power take-off controller for operating the power take-off unit in communication with the level controller;

manual means for engaging and operating the power take-off controller; and

the level controller being responsive to engagement of the power take-off controller for operating in its first mode and to disengagement of the power take-off controller for operating in its second mode.

10. A vehicle chassis in accord with claim 9, further comprising:

the level controller being operable in its first mode for limiting operation of the power take-off controller in response to suspension extension sensors indicating maximum allowed compression or extension of any air bag.

11. A vehicle chassis in accord with claim 10, further comprising:

the level controller being operable for preventing operation of the power take-off controller in response to initial engagement thereof if the vehicle chassis cannot be leveled with the mobile aerial lift unit is in a stowed condition.