System for generating signals for control or regulation of a chassis controllable or regulable in its sequences of movement

• US 5,488,562 A
• Filed: 01/27/1993
• Issued: 01/30/1996
• Est. Priority Date: 05/31/1991
• Status: Expired due to Term

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Kallenbach, Rainer, Landesfeind, Klaus, Kunz, Dieter, Otterbein, Stefan
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): NGUYEN, TAN QUANG
• Application Number:
  US07/969,840
• Time in Patent Office: 1,098 Days
• Field of Search: 364/424.05, 364/426.04, 280/707, 280/688, 280/840, 280/772, 180/170, 180/197, 180/41, 180/282, 180/140, 180/153
• US Class Current: 701/38
• CPC Class Codes: B60G 17/0182 involving parameter estimation, e.g. observer, Kalman filter
• CPC Class Codes: B60G 2400/102 vertical
• CPC Class Codes: B60G 2400/104 lateral or transversal with regard to vehicle
• 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 2400/202 Piston speed; Relative velocity between vehicle body and wheel
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/208 of wheel rotation
• CPC Class Codes: B60G 2400/252 vertical
• CPC Class Codes: B60G 2400/34 Accelerator pedal position
• CPC Class Codes: B60G 2400/41 Steering angle
• CPC Class Codes: B60G 2400/51 in suspension unit
• CPC Class Codes: B60G 2400/61 Load distribution
• CPC Class Codes: B60G 2400/63 Location of the center of gravity
• CPC Class Codes: B60G 2500/10 Damping action or damper
• CPC Class Codes: B60G 2500/20 Spring action or springs
• CPC Class Codes: B60G 2500/30 Height or ground clearance
• CPC Class Codes: B60G 2600/14 Differentiating means, i.e. differential control
• CPC Class Codes: B60G 2600/16 Integrating means, i.e. integral control
• CPC Class Codes: B60G 2600/60 Signal noise suppression; Electronic filtering means
• CPC Class Codes: B60G 2600/74 : Analog systems
• CPC Class Codes: B60G 2600/76 : Digital systems
• CPC Class Codes: B60G 2600/90 : other signal treatment means
• CPC Class Codes: B60G 2800/012 : Rolling condition
• CPC Class Codes: B60G 2800/014 : Pitch; Nose dive
• CPC Class Codes: B60G 2800/18 : Starting, accelerating
• CPC Class Codes: B60G 2800/22 : Braking, stopping
• CPC Class Codes: B60G 2800/24 : Steering, cornering
• CPC Class Codes: B60G 2800/90 : System Controller type
• CPC Class Codes: B60G 2800/92 : ABS - Brake Control

Abstract

The object of the inventional system is the so-called "modal" variant of the skyhook damping. The advantage of this variant over the local version is essentially constituted by enabling an individual damping of the eigenoscillation forms. Moreover, a definitive roll or sway moment distribution can be adjusted. For that purpose there are signals determined which represent the local vehicle body movements at selected points of the vehicle body. Basing on these signals, the heave, roll and pitch movements are inferred. These movements are differently weighted depending on travel maneuvers. By actuation of the damper systems dependent on the weighted heave, roll and pitch movements a specific influencing of certain components of the body movement is possible.

Claims

1. A control system for controlling and regulating a vehicle body, said vehicle body subject to heave, pitch, and roll movements, said body connected to a plurality of wheels, a deflectable spring, and first and second adjustable suspension systems, said first and second suspension systems connected between said body and respective said wheels, said first and second suspension systems being individually independently adjustable to influence movements of said respective wheels relative to said body, said control system comprising:

means for determining a plurality of first signals which respectively represent body velocities at a plurality of preselected points of said body;

means for generating second signals based on said first signals, said second signals representing heave, roll, and pitch movements of said body;

means for generating third signals based on said second signals, said third signals representing eigenoscillation forms of said body velocities; and

means for generating actuating signals based on said third signals, for independently adjusting said first and second suspension systems.

2. The control system of claim 1 for controlling and regulating a vehicle having front and rear axles, said first and second suspension systems respectively associated with said front and rear axles, wherein said actuating signal generating means independently adjusts said first and second suspension systems to adjust for roll movements.

3. The control system of claim 1 for controlling and regulating a vehicle wherein said suspension systems apply forces between the wheels and the vehicle body, wherein said actuating signal generating means generates actuating signals for exerting control forces said suspension systems which correspond to set forces.

4. The control system of claim 3 for controlling and regulating a vehicle wherein the suspension systems are semiactive suspension systems, said control system including means for determining deflection movements of a said spring, said actuating signal generating means generating semiactive control signal based on a comparison of said actuating signals with said spring deflection movements, whereby said semiactive control signals specify application of one of a maximally hard and a maximally soft setting.

5. The control system of claim 3 for controlling and regulating a vehicle wherein the said suspension systems are semiactive suspension systems, said control system including means for determining relative movements between the said wheels and the vehicle body, said actuating signal generating means generating semiactive control signals based on said set forces and the relative movements between the said wheels and the said vehicle body, whereby said semiactive control signals specify application of one of a maximally hard and a maximally soft setting.

6. The control system of claim 3 for controlling and regulating a vehicle having suspension systems with nonlinear performance and wherein said actuating signals include linear control voltages, said control system further comprising means to compensate for the said nonlinear control performance of the said suspension systems and to generate control forces corresponding to the said set forces.

7. The control system of claim 1 for controlling and regulating a vehicle wherein the said suspension systems are semiactive suspension systems, said control system further comprising a plurality of damper systems having means for actuating damper pistons.

8. The control system of claim 7 wherein said actuating means includes a throttle valve having a flow cross section which is variable.

9. The control system of claim 7 wherein said actuating means includes a pressure-limiting valve.

10. The control system of claim 1 wherein said first signals represent velocities of the vehicle body in a vertical direction, said actuating signal generating means including weighting means for arithmetically weighting said third signals with variables related to travel dynamics of the vehicle, and said actuating signal generating means further including combining means for combining two signals from said third signals and said weighted third signals, and said combining means provides signals for exerting control forces on the suspension systems which correspond to set forth.

11. The control system of claim 10 wherein said weighting means weights said second signals according to the matrix:

##EQU13## where each coefficient gkk, gkn, gw, gnk and gnn depends on one of a constant value and a variable relating to travel dynamics of the vehicle.

12. The control system of claim 10 for controlling and regulating a vehicle wherein the said vehicle has four wheels, two axles, and two springs, said first and second suspension systems each including a damper, said damper and said deflectable springs arranged between a said wheel and the said vehicle body, wherein said combining means combines said second signals and weighted signals according to the matrix:

##EQU14## where F11=F21=a2/(a1+a2);

F31=F41=a1/(a1+a2);

F12=-F22=(1/b1)*(ro/ro+1);

F32=-F42=(1/b2)*(1/ro+1);

F43=F33=-F23=-F13=1/(a1+a2);

a1 is the distance between the center of gravity of the vehicle body and the front axle;

a2 is the distance between the center of gravity of the vehicle body and the rear axle;

2*b1 is the spacing of the attachment points of a said damper to the vehicle body at the front axle;

2*b2 is the spacing of the attachment points of a said damper to the vehicle body at the rear axle;

whereby said signals for exerting the set forces are generated.

13. The control system of claim 1 wherein said actuating signal generating means generates said actuating signals depending on travel dynamics of said vehicle, said travel dynamics including at least one of the transverse and longitudinal acceleration of the vehicle, and the vehicle travel speed, said control system further comprising means for determining the said travel dynamics which includes at least one of the following:

means for determining transverse movements of the vehicle body based on signals of steering angle sensors;

means for determining longitudinal movements of the vehicle body based on signals of wheel speed sensors;

means for determining longitudinal and transverse movements of the vehicle body based on signals of acceleration sensors; and

means for determining longitudinal movements of the vehicle body based on the position of an operator activated pedal.

14. The control system of claim 1 for controlling and regulating a vehicle which includes acceleration sensors connected to the said vehicle body at preselected points for generating signals representing vertical accelerations of the said vehicle body, wherein said means for determining a plurality of said first signals determines said first signals by integrating the acceleration sensor generated signals.

15. The control System of claim 14 wherein said plurality of first signals represent velocities of the said vehicle body in the vertical direction at three preselected points of the said vehicle body, and said second signal generating means linearly combines said first signals using the matrix:

##EQU15## where det A=(y2-y3)*x1+(y3-y1)*x2+(y1-y2)*x3;

xi and yi are coordinates of the selected points with regard to a body-fixed two-dimensional coordinate system having a center of gravity of the body as zero point, with index i=1,2,3; and

the coordinates (xi, yi) of the selected points have values such that (det A) does not equal zero.

16. The control System of claim 14 wherein said plurality of first signals represent velocities of the said vehicle body in a vertical direction at four preselected points of the said vehicle body, and the said means for generating second signals linearly combines said first signals using the matrix:

##EQU16## where B11=B12=-x3/(x1-x3);

B13=B14=x1/(x1-x3 );

B21=-B22=y1/(y1² +y3²);

B23=-B24=y3/(y1² +y3²);

B31=B32=-1/(x1-x3);

B33=B34=1/(x1-x3);

xi and yi are the coordinates of the four points with respect to a body-fixed two-dimensional coordinate system having a center of gravity of the vehicle body as zero point, with the index i=1,2,3,4;

the coordinates (xi, yi) of the four points have values such that x3 is not equal to x1, y1² +y3² >

0, x2=x1, y2=-y1, x4=x3 and y4=-y3.

17. The control system of claim 1 wherein said first signals represent velocities of the said vehicle body in a vertical direction at four preselected points of the said vehicle body, said control system further comprising means for generating an error signal based on said first signals, said error signal being determined according to the mathematical equation of the variable r:

##EQU17## where Vk represents one of said first signals associated with said first point, with k=1 through 4;

with the elements rik given by the matrix R;

##EQU18## where yi representing coordinates of a preselected point in the transverse direction of the vehicle with respect to a body-fixed two-dimensional coordinate system having a center of gravity of the body as zero point, where the index i=1,2,3,4;

y2=-y1 and y4=-y3;

said error signal generating means comparing the value of the variable r to predetermined thresholds, and said error signal generating means generating an error signal if said predetermined thresholds are exceeded.