Vehicle active suspension system incorporating acceleration detecting means

• US 4,712,807 A
• Filed: 02/05/1986
• Issued: 12/15/1987
• Est. Priority Date: 02/06/1985
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kurosawa, Ryuichi
• Primary Examiner(s): Love, John J.
• Assistant Examiner(s): Ferriter, Karin L.
• Application Number:
  US06/826,320
• Time in Patent Office: 678 Days
• Field of Search: 280/6 R, 280/6 H, 280/703, 280/707, 280/709, 280/DIG. 1, 280/714, 188/299, 364/424
• US Class Current: 280/5.508
• 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 17/0162 mainly during a motion involving steering operation, e.g. cornering, overtaking B60G17/0164 takes precedence
• CPC Class Codes: B60G 17/018 characterised by the use of a specific signal treatment or control method
• CPC Class Codes: B60G 2204/81 front and rear unit
• 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 2400/51 in suspension unit
• CPC Class Codes: B60G 2400/60 Load
• CPC Class Codes: B60G 2400/841 Wind
• CPC Class Codes: B60G 2500/40 Steering
• CPC Class Codes: B60G 2600/182 Active control 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 2800/24 Steering, cornering

Abstract

A vehicle, which has a body and a plurality of wheels, has a suspension system which includes: an actuator for each wheel, each of which supports the body from one of wheels and is controllable to provide a variable force between the body and the wheel; a sensor for detecting acceleration of the body and for producing a signal representative thereof, a sensor for each wheel for detecting load acting between the body and the wheel and for producing a signal representative thereof; and a controller for inputting the signals representative of the acceleration of the body and the load on each wheel, for calculating based thereupon fluctations in load acting between the wheels and the body, for controlling the actuators to increase or decrease forces provided thereby between the body and the wheels, and for operating by feedback action by comparing the actual fluctuation in the force between the respective wheel and the body as sensed by the load sensor for the wheel with the calculated value therefor, and for bringing the difference between the two values to be zero. Optionally, the acceleration sensor can include either a means for sensing lateral acceleration or a means for sensing roll angle acceleration or both of these; and in the latter case this control means can utilize for control either the lateral acceleration information or the roll angle information, depending on whether the signs of these accelerations are opposite or are the same, respectively.

Claims

1. A suspension system for a vehicle comprising a body and a plurality of wheels, comprising:

a plurality of actuators, each of which supports said body from one of said wheels and is controllable to provide a variable force between said body and said wheels;

a sensor means for detecting acceleration of said body in lateral directions thereof and for producing a signal representative thereof;

a sensor means for detecting roll angle acceleration of said body and for producing a signal representative thereof; and

a control means for inputting said signals representative of said lateral acceleration and said roll angle acceleration of said body from said sensor means, for calculating based thereupon fluctuations in load acting between said wheels and said body caused by said accelerations, and for controlling said actuators to increase or decrease forces provided thereby between said body and said wheels, wherein said control means comprises a means for;

(a) detecting whether or not the direction of lateral acceleration of said body as determined by said lateral acceleration detecting means is the same as or is the opposite to the direction of roll acceleration of said body as considered for a point above the center of gravity of said vehicles; and

for;

(b) if said directions are the same, calculating, based upon said signal representative of said roll angle acceleration of said body from said sensor means therefor, fluctuations in load acting between said wheels and said body caused by said acceleration, and based thereupon controlling said actuators to increase or decrease forces provided thereby between said body and said wheels; and

for;

(c) if said directions are opposite, calculating, based upon said signal representative of said lateral acceleration of said body from said sensor means therefor, fluctuations in load acting between said wheels and said body caused by said acceleration, and based thereupon controlling said acutators to increase or decrease forces provided thereby between said body and said wheels.

2. A suspension system according to claim 1, wherein said accelerating detecting sensor means comprises a means for detecting acceleration of said vehicle body in the longitudinal direction thereof.

3. A suspension system for a vehicle comprising a body and a plurality of wheels comprising:

a plurality of actuators, each of which supports said body from one of said wheels and is controllable to provide a variable force between said body and said wheels;

a sensor means for detecting acceleration of said body in lateral directions thereof and for producing a signal representative thereof; and

for detecting roll angle acceleration of said body and for producing a signal representative thereof;

for each said wheel, load sensor means for detecting the value of the load between said wheel and said body and for outputting a signal representative thereof; and

a control means for inputting said signals representative of said lateral acceleration and said roll angle acceleration of said body from said sensor means and said signals representative of said lateral acceleration, said roll angle acceleration and said load from said sensor means, for calculating based thereupon fluctuations in load acting between said wheels and said body caused by said accelerations, for controlling said actuators to increase or decrease forces provided thereby between said body and said wheels, and for operating by feedback action by comparing the actual fluctuation in the force between the respective wheel of each said actuator and said body as sensed by said load sensor means for said wheel with the calculated value therefor, and for bringing the difference between said values to be zero wherein said control means comprises a means for;

(a) detecting whether or not the direction of lateral acceleration of said body as determined by said lateral acceleration detecting means is the same as or is the opposite to the direction of roll acceleration of said body as considered for a point above the center of gravity of said vehicle; and

for;

(b) if said directions are the same, calculating, based upon said signal representative of said roll angle acceleration of said body from said sensor means therefor, fluctuations in load acting between said wheels and said body caused by said acceleration, and based thereupon controlling said actuators to increase or decrease forces provided thereby between said body and said wheels; and

for;

(c) if said directions are opposite, calculating, based upon said signal representative of said lateral acceleration of said body from said sensor means therefor, fluctuations in load acting between said wheels and said body caused by said acceleration, and based thereupon controlling said actuators to increase or decrease forces provided thereby between said body and said wheels.

4. A suspension system according to claim 3, wherein said accelerating detecting sensor means comprises a means for detecting acceleration of said vehicle body in the longitudinal direction thereof.

5. A suspension system for a vehicle comprising a body and two front and two rear wheels, comprising:

a plurality of actuators, each of which supports said body from one of said wheels and is controllable to provide a variable force between said body and said wheels;

a sensor means, comprising a means for detecting acceleration of said vehicle body in the lateral direction thereof and a means for detecting roll angle acceleration of said vehicle body; and

a control means for inputting said signal representative of said acceleration of said body from said sensor means, for calculating based thereupon fluctuations in load acting between said wheels and said body caused by said acceleration, and for controlling said actuators to increase or decrease forces provided thereby between said body and said wheels, comprising a means for;

(a) detecting whether or not the direction of lateral acceleration of said body as determined by said lateral acceleration detecting means is the same as or is the opposite to the direction of roll acceleration of said body as considered for a point above the center of gravity of said vehicle; and

for;

(b) if said directions are the same, calculating, based upon said signal representative of said roll angle acceleration of said body from said sensor means therefor, the magnitude of the total fluctuation in load acting between said front and said rear wheels on each side and said body caused by said acceleration, performing a distribution calculation on said total fluctuation between said front and said rear wheels according to a certain ratio, and based thereupon controlling said actuators to increase or decrease forces provided thereby between said body and said wheels; and

for;

(c) if said directions are opposite, calculating, based upon said signal representative of said lateral acceleration of said body from said sensor means therefor, the magnitude of the total fluctuation in load acting between said wheels and said body caused by said acceleration, performing a distribution calculation on said total fluctuation between said front and said rear wheels according to said certain ratio, and based thereupon controlling said actuators to increase or decrease forces provided thereby between said body and said wheels.

7. A suspension system according to claim 5 or claim 6, wherein said certain ratio is substantially equal to unity.

8. A suspension system according to claim 5 or claim 6, wherein said certain ratio is substantially greater than unity.

9. A suspension system according to claim 5 or claim 6, wherein said certain ratio is substantially less than unity.

6. A suspension system for a vehicle comprising a body and two front and two rear wheels, comprising:

a plurality of actuators, each of which supports said body from one of said wheels and is controllable to provide a variable force between said body and said wheels;

a sensor means, comprising a means for detecting acceleration of said vehicle body in the lateral direction thereof and a means for detecting roll angle acceleration of said vehicle body; and

a control means for inputting said signal representative of said acceleration of said body from said sensor means, for calculating based thereupon fluctuations in load acting between said wheels and said body caused by said acceleration, and for controlling said actuators to increase or decrease forces provided thereby between said body and said wheels, comprising a means for;

(a) detecting whether or not the direction of lateral acceleration of said body as determined by said lateral acceleration detecting means is the same as or is the opposite to the direction of roll acceleration of said body as considered for a point above the center of gravity of said vehicle; and

for;

(b) if said directions are the same, calculating, based upon said signal representative of said roll angle acceleration of said body from said sensor means therefor, the magnitude of the total fluctuation in load acting between said front and said rear wheels on each side and said body caused by said acceleration, performing a distribution calculation on said total fluctuation between said front and said rear wheels according to a certain ratio, and based thereupon controlling said actuators to increase or decrease forces provided thereby between said body and said wheels, operating by feedback action by comparing the actual fluctuation in the force between the respective wheel of each said actuator and said body as sensed by said load sensor means for said wheel with the calculated value therefor, and bringing the difference between said values to be zero; and

for;

(c) if said directions are opposite, calculating, based upon said signal representative of said lateral acceleration of said body from said sensor means therefor, the magnitude of the total fluctuation in load acting between said wheels and said body caused by said acceleration, performing a distribution calculation on said total fluctuation between said front and said rear wheels according to said certain ratio, based thereupon controlling said actuators to increase or decrease forces provided thereby between said body and said wheels, operating by feedback action by comparing the actual fluctuation in the force between the respective wheel of each said actuator and said body as sensed by said load sensor means for said wheel with the calculated value therefor, and bringing the difference between said values to be zero.

10. A suspension system for a vehicle comprising a body and two front and two rear wheels, comprising:

a plurality of actuators, each of which supports said body from one of said wheels and is controllable to provide a variable force between said body and said wheels;

a sensor means, comprising a means for detecting acceleration of said vehicle body in the lateral direction thereof and a means for detecting roll angle acceleration of said vehicle body; and

a control means for inputting said signal representative of said acceleration of said body from said sensor means, for calculating based thereupon fluctuations in load acting between said wheels and said body caused by said acceleration, and for controlling said actuators to increase or decrease forces provided thereby between said body and said wheels, comprising a means for;

(a) detecting whether or not the direction of lateral acceleration of said body as determined by said lateral acceleration detecting means is the same as or is the opposite in the direction of roll acceleration of said body as considered for a point above the center of gravity of said vehicle; and

for;

(b) if said directions are the same, calculating, based upon said signal representative of said roll angle acceleration of said body from said sensor means therefor, the magnitude of the total fluctuation in load acting between said front and said rear wheels on each side and said body caused by said acceleration, performing a distribution calculation on said total fluctuation between said front and said rear wheels according to a first ratio, and based thereupon controlling said actuators to increase or decrease forces provided thereby between said body and said wheels; and

for;

(c) if said directions are opposite, calculating, based upon said signal representative of said lateral acceleration of said body from said sensor means therefor, the magnitude of the total fluctuation in load acting between said wheels and said body caused by said acceleration, performing a distribution calculation on said total fluctuation between said front and said rear wheels according to a second ratio, and based thereupon controlling said actuators to increase or decrease forces provided thereby between said body and said wheels.

12. A suspension system according to claim 10 or claim 11, wherein said first and said second ratio are substantially different.

11. A suspension system for a vehicle comprising a body and two front and two rear wheels, comprising:

a plurality of actuators, each of which supports said body from one of said wheels and is controllable to provide a variable force between said body and said wheels;

a sensor means, comprising a means for detecting acceleration of said vehicle body in the lateral direction thereof and a means for detecting roll angle acceleration of said vehicle body; and

a control means for inputting said signal representative of said acceleration of said body from said sensor means, for calculating based thereupon fluctuations in load acting between said wheels and said body caused by said acceleration, and for controlling said actuators to increase or decrease forces provided thereby between said body and said wheels, comprising a means for;

(a) detecting whether or not the direction of lateral acceleration of said body as determined by said lateral acceleration detecting means is the same as or is the opposite to the direction of roll acceleration of said body as considered for a point above the center of gravity of said vehicle; and

for;

(b) if said directions are the same, calculating, based upon said signal representative of said roll angle acceleration of said body from said sensor means therefor, the magnitude of the total fluctuation in load acting between said front and said rear wheels on each side and said body caused by said acceleration, performing a distribution calculation on said total fluctuation between said front and said rear wheels according to a first ratio, and based thereupon controlling said actuators to increase or decrease forces provided thereby between said body and said wheels, operating by feedback action by comparing the actual fluctuation in the force between the respective wheel of each said actuator and said body as sensed by said load sensor means for said wheel with the calculated value therefor, and bringing the difference between said values to be zero; and

for;

(c) if said directions are opposite, calculating, based upon said signal representative of said lateral acceleration of said body from said sensor means therefor, the magnitude of the total fluctuation in load acting between said wheels and said body caused by said acceleration, performing a distribution calculation on said total fluctuation between said front and said rear wheels according to a second ratio, based thereupon controlling said actuators to increase or decrease forces provided thereby between said body and said wheels, operating by feedback action by comparing the actual fluctuation in the force between the respective wheel of each said actuator and said body as sensed by said load sensor means for said wheel with the calculated value therefor, and bringing the difference between said values to be zero.