Vehicle stability system: using active tilting mechanism as a counter measure to natural tilt

• US 20060076741A1
• Filed: 11/28/2005
• Published: 04/13/2006
• Est. Priority Date: 11/22/2000
• Status: Abandoned Application

• Current Assignee: Howard Tak Su Lim
• Original Assignee: Howard Tak Su Lim
• Inventors: Lim, Howard Tak Su
• Application Number:
  US11/287,694
• Publication Number:
  US 20060076741A1
• Time in Patent Office: Days
• US Class Current: 280/5.508
• CPC Class Codes: B60G 15/067 characterised by the mounting on the vehicle body or chassis of the spring and damper unit
• CPC Class Codes: B60G 17/015 the regulating means comprising electric or electronic elements B60G17/002, B60G17/005 take precedence
• CPC Class Codes: B60G 17/0162 mainly during a motion involving steering operation, e.g. cornering, overtaking B60G17/0164 takes precedence
• CPC Class Codes: B60G 17/021 the mechanical spring being a coil spring B60G17/0272 takes precedence
• CPC Class Codes: B60G 2400/0511 Roll angle
• CPC Class Codes: B60G 2400/0523 Yaw rate
• CPC Class Codes: B60G 2400/106 longitudinal with regard to vehicle, e.g. braking
• CPC Class Codes: B60G 2400/20 Speed
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/252 vertical
• CPC Class Codes: B60G 2400/41 Steering angle
• CPC Class Codes: B60G 2400/61 Load distribution
• CPC Class Codes: B60G 2400/63 Location of the center of gravity
• CPC Class Codes: B60G 2500/326 only left or right side
• CPC Class Codes: B60G 2800/012 Rolling condition
• CPC Class Codes: B60G 2800/0124 Roll-over conditions
• CPC Class Codes: B60G 2800/019 Inclination due to load distribution or road gradient
• CPC Class Codes: B60G 2800/0194 transversal with regard to vehicle
• CPC Class Codes: B60G 2800/224 automatically, based on dangerous living style
• CPC Class Codes: B60G 2800/91 Suspension Control
• CPC Class Codes: B60T 2230/03 : Overturn, rollover
• CPC Class Codes: B60T 2260/06 : Active Suspension System
• CPC Class Codes: B60T 8/17554 : specially adapted for enhancing stability around the vehicles longitudinal axle, i.e. roll-over prevention road vehicle drive control systems for roll-over prevention otherwise than by controlling a particular sub-unit B60W30/04

Abstract

The present invention is a vehicle stability system that affords safe turn with higher speed as well as maximum brake performance and resists rollover by using one or more electrical and mechanical modes to shift the center of gravity of the vehicle into a more stable position in the event of a turn condition. A preferred embodiment of the present invention utilizes an active tilt control to tilt the vehicle in the opposite direction to the vehicle'"'"'s natural inclination to tilt. A second preferred embodiment utilizes a shifting weight, that is a ballast or any heavy part of the vehicle to move the center of gravity toward to side of the vehicle tending to lift up during a tilt condition. The first and second preferred embodiments can be used alone or in a combination to create a more dynamic stable condition for the vehicle in turn mode.

Claims

1. A vehicle control system comprising:

a tilt control processing unit;

a plurality of sensors for determining and communicating vehicle conditions to the tilt control processing unit;

a lifting mechanism for lifting a designated side of the vehicle in response to a judging by the tilt control processing unit that an active tilt condition is necessary wherein the lifting mechanism compensates for a natural tilt of the vehicle by lifting the designated side of the vehicle so that a natural tilt force vector is approximately at a right angle with a horizontal line of the vehicle.

2. The vehicle control system of claim 1 wherein at least one sensor measures the velocity of the vehicle.

3. The vehicle control system of claim 2 wherein at least one sensor measures the instantaneous turning radius of the vehicle during a turning maneuver.

4. The vehicle control system of claim 3 wherein the tilt control processing unit also factors into the judging, the location of the center of gravity of the vehicle.

5. The vehicle control system of claim 3 wherein at least one sensor measures the force generated by a crosswind on the vehicle.

6. The vehicle control system of claim 3 wherein at least one sensor measures current vehicle tilt status.

7. The vehicle control system of claim 1 wherein the lifting mechanism comprises a vehicle suspension system and controller, and a secondary suspension support unit and controller.

8. A vehicle stability system comprising:

a plurality of sensors for determining and communicating vehicle conditions; and

a processing unit communicatively coupled to the plurality of sensors, the processing unit configured to;

determine when a vehicle is turning,

determine a natural tilt force of the vehicle as it is turning, and

generate an output signal that causes a designated side of the vehicle to either lift or lower so that the natural tilt force is approximately at a right angle with a horizontal line of the vehicle.

9. The vehicle stability system of claim 8 further comprising:

a lifting mechanism for lifting the designated side of the vehicle in response to the output signal from the processing unit.

10. The vehicle stability system of claim 8 wherein the natural tilt force vector of the vehicle is determined from a centrifugal force for the vehicle and weight gravity force for the vehicle.

11. The vehicle stability system of claim 8 wherein the processing unit is configured to:

determine a turning direction of the vehicle;

determine an absolute natural tilt angle formed between the natural tilt force and a weight gravity force for the vehicle; and

determine an ideal tilting angle so that, when the vehicle is at a dynamic stable state, the natural tilt force is at approximately ninety degrees with the horizontal line of the vehicle, wherein when the vehicle is placed at the ideal tilting angle less lateral force is perceived within the vehicle.

12. A vehicle comprising:

a steering wheel to permit the vehicle to turn in a particular turn direction D;

a height adjustment mechanism for lowering and lifting a designated side of the vehicle in response to movement of the steering wheel;

a mechanical connection between the steering wheel and the height adjustment mechanism, wherein turning of the steering wheel causes the height adjustment mechanism to either raise or lower a designated side of the vehicle; and

a dynamic stability control system communicatively coupled to the height adjustment mechanism, the vehicle stability system configured to adjust the height adjustment mechanism to compensate for a natural tilt of the vehicle during a turning maneuver so that a natural tilt force of the vehicle is approximately at a right angle with a horizontal plane of the vehicle.

13. The vehicle of claim 12 further comprising:

a plurality of sensors coupled to the vehicle stability system, the plurality of sensors measuring the turn direction D, a circular radius R of the vehicle'"'"'s turn, a vehicle velocity V, a vehicle weight gravity force W, a road tilt angle U, a center of gravity height H, a pushing factor P, and a vehicle tilting angle Q, and

the vehicle stability system is being configured to;

determine a centrifugal force F exerted on the vehicle from the velocity V and circular radius R, the centrifugal force F being perpendicular to the velocity V in the direction away from the center of the circular radius R, where F≈

M*V²/R,

determine the natural tilt force T from the centrifugal force F and the vehicle weight gravity force W, where T≈

(F²+W²)^1/2,

determine an absolute natural tilt angle A that is formed between the natural tilt force T and the weight force W, where A≈

COSINE<sup>−

1</sup> (W/T),

determine an ideal tilting angle A′

between the horizontal line of the vehicle and line of the earth'"'"'s flat surface, a vertex of the ideal tilting angle A′

located at the same side as the turn direction D and where A′

>

0;

determine a deviation angle a from other factors affecting said absolute natural tilting angle A including a road tilt angle U, pushing factors P against the vehicle, and center of gravity height H of the vehicle, where a≈

U+κ

PH and where κ

is constant;

determine a relative natural tilt angle B adjusted from the absolute natural tilt angle A, formulating B≅

A±

α

, and

generate the output which causes the vehicle'"'"'s ideal tilting angle A′

to be substantially same as or close to the relative natural tilt angle B to achieve a dynamic stable state having none or minimum lateral force.

14. A vehicle control system that actively tilts a vehicle chassis in response to a natural tilt force, comprising:

a plurality of sensors;

a tilt control processing unit that processes information from the plurality of sensors, calculates the natural tilt force, and issues commands based on the calculation; and

a lifting mechanism that responds to the commands by the tilt control processing unit by asymmetrically lifting or lowering the vehicle chassis until the vehicle is perpendicular to the natural tilt force.

15. The vehicle control system of claim 14 wherein the tilt control processing unit uses center of gravity in its calculations.

16. The vehicle control system of claim 14 wherein the lifting mechanism includes:

a vehicle suspension system, and

a controller that controls the vehicle suspension system.

17. The vehicle control system of claim 14 wherein one of the plurality of sensors measures tilt of the vehicle chassis.

18. The vehicle control system of claim 14 wherein the tilt control processing unit uses the vehicle center of gravity in its calculations.

19. A smart vehicle system that reduces lateral forces in a vehicle chassis, comprising:

a plurality of sensors that gather information about vehicle speed and turning radius for processing;

a tilt control processing unit that processes the information from the plurality of sensors, calculates an active tilt angle and issues commands based on the active tilt angle;

a lifting mechanism that responds to the commands of the tilt control processing unit by lifting or lowering a first side or a second side of the vehicle chassis.

20. The smart vehicle system of claim 19 wherein the lifting mechanism lifts the first side or the second side of the vehicle when the active tilt angle indicates an active tilt condition.

21. The smart vehicle system of claim 19 wherein the lifting mechanism lifts the first or second side of the vehicle until the vehicle chassis is at the active tilt angle.