Process and device for chassis control

• US 5,383,123 A
• Filed: 10/27/1992
• Issued: 01/17/1995
• Est. Priority Date: 12/06/1991
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Kunz, Dieter
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): NGUYEN, TAN QUANG
• Application Number:
  US07/967,199
• Time in Patent Office: 812 Days
• Field of Search: 364/424.05, 364/424.01, 364/426.01, 364/426.02, 280/707, 180/41
• US Class Current: 701/37
• CPC Class Codes: B60G 17/0164 mainly during accelerating or braking
• CPC Class Codes: B60G 2400/102 vertical
• 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 2400/60 Load
• CPC Class Codes: B60G 2400/91 Frequency
• CPC Class Codes: B60G 2600/14 Differentiating means, i.e. differential control
• CPC Class Codes: B60G 2600/604 low pass
• CPC Class Codes: B60G 2800/18 Starting, accelerating
• CPC Class Codes: B60G 2800/22 Braking, stopping

Abstract

Suspension systems are actuated during braking and/or acceleration maneuvers whereby each wheel unit has a momentary normal force between the tire and road surface, i.e., the wheel load which is influenced in the direction of its greatest possible value. For that purpose, the progression of the wheel load, specifically the dynamic share, is determined from the sensed movements between the wheel units and the vehicle body and/or from the sensed movements of the wheel units. Results of a frequency analysis of the wheel loads and the time progression, specifically the time derivation of the wheel load, are utilized for adjustment of the suspension systems in the sense described above. The suspension systems between the vehicle body and wheels are during braking and/or acceleration maneuvers actuated whereby the mean spacing between the vehicle body and the wheels units is time-progressively reduced during the braking and/or acceleration maneuvers.

Claims

1. A process for chassis control of a vehicle, the vehicle including a body, a plurality of wheel units and at least one suspension system disposed between the body and a respective one of the wheel units, each said suspension system influencing relative movements between the body and the respective wheel unit, said process comprising the steps of:

sensing at least one of a relative movement between the body and the respective wheel unit, and an absolute movement of the wheel unit, said sensed movement corresponding to one of a plurality of discrete time segments defining a time period; and

actuating the suspension system during selected ones of said plurality of discrete time segments in one of a braking and accelerating maneuver of the vehicle, each said actuation influencing a momentary normal force between the respective wheel unit and a road surface toward a maximum value.

2. The process according to claim 1, wherein said actuating step is carried out dependent on a frequency and a time progression of the momentary normal force.

3. The process according to claim 1, further comprising the step of generating a first signal representing at least a dynamic share of the momentary normal force.

4. The process according to claim 3, wherein said generating step comprises generating said first signal dependent on said sensed movement.

5. The process according to claim 3, comprising the further steps of evaluating the first signal frequency-selectively and generating a second signal dependent on said evaluation, and comparing the second signal with a first threshold, said actuating step dependent on said comparison.

6. The process according to claim 3, comprising the further steps of differentiating the first signal and generating a third signal dependent on said differentiation, and comparing the third signal with a second threshold, said actuating step dependent on said comparison.

7. The process according to claim 3, comprising the further steps of evaluating the first signal frequency-selectively and generating a second signal dependent on said evaluation, and performing a first comparison between the second signal and a first threshold, said actuating step dependent on said first comparison;

and

comprising the further steps of differentiating the first signal and generating a third signal dependent on said differentiation, and performing a second comparison between the third signal and a second threshold, said actuating step dependent on said second comparison.

8. The process according to claim 1, wherein said actuating step is carried out during said accelerating maneuver, said accelerating maneuver corresponding to a numeric value of an acceleration of the vehicle which is greater than a selectable threshold level.

9. The process according to claim 1, wherein said process is carried out when at least one of an antilock and drive slip control system present on the vehicle intervenes in one of controlling and regulating the vehicle in the braking and accelerating maneuver.

10. The process according to claim 1, wherein the momentary normal force between the respective wheel unit and the road surface defines a wheel load of the respective wheel unit.

11. A chassis control system for a vehicle, the vehicle including a body, and a plurality of wheel units, said chassis control system comprising:

means for sensing at least one of a relative movement between the body and the respective wheel unit, and an absolute movement of the wheel unit, said sensed movement corresponding to one of a plurality of discrete time segments defining a time period;

at least one suspension system disposed between the body and a respective one of the wheel units, each said suspension system influencing relative movements between the body and the respective wheel unit; and

means for actuating the suspension system during selected ones of said plurality of discrete time segments in one of a braking and accelerating maneuver of the vehicle, each said actuation decreasing an average distance between the vehicle body and the respective wheel unit.

12. The system according to claim 11, further comprising means for generating a first signal representing at least a dynamic share of a momentary normal force between the respective wheel unit and a road surface.

13. The system according to claim 12, further comprising means for frequency analyzing said generating means signal, means for differentiating said generating means signal, and means for threshold value scanning of the frequency analyzed generating means signal and the differentiated generating means signal.

14. The system of claim 12, wherein said dynamic share is dependent on said sensed movement.