Anti-rolling control for actively controlled automobile suspension system with enhanced rolling detecting ability

• US 5,087,068 A
• Filed: 06/12/1989
• Issued: 02/11/1992
• Est. Priority Date: 06/10/1988
• Status: Expired due to Term

• Current Assignee: Nissan Motor Company Limited 2 Takara-Cho Kanagawa-Ku Yokohama-Shi Kanagawa-Ken Japan
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Satoh, Masaharu, Fukanaga, Yukio, Fujimura, Itaru, Fukushima, Naoto, Akatsu, Yohsuke
• Primary Examiner(s): Marmor, Charles A,
• Assistant Examiner(s): Tyson, Karin
• Application Number:
  US07/364,477
• Time in Patent Office: 974 Days
• Field of Search: 280/707, 280/DIG. 1, 280/6.12, 280/689, 280/772, 364/424.05
• US Class Current: 280/5.508
• CPC Class Codes: B60G 17/0163 the control involving steering geometry, e.g. four-wheel steering
• CPC Class Codes: B60G 2204/80 Interactive suspensions; arrangement affecting more than one suspension unit
• CPC Class Codes: B60G 2400/10 Acceleration; Deceleration
• CPC Class Codes: B60G 2400/104 lateral or transversal with regard to vehicle
• CPC Class Codes: B60G 2400/1042 using at least two sensors
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/41 Steering angle
• CPC Class Codes: B60G 2400/63 Location of the center of gravity
• CPC Class Codes: B60G 2500/22 Spring constant
• CPC Class Codes: B60G 2500/326 only left or right side
• CPC Class Codes: B60G 2600/70 Computer memory; Data storage, e.g. maps for adaptive control
• 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

Abstract

An actively controlled suspension system employs a lateral acceleration sensor for monitoring lateral acceleration exerted on the vehicular body. The lateral acceleration is shifted frontwardly from a gravity center of the vehicle body at the neutral position or non-rolling condition. The magnitude of frontward offset of the lateral acceleration sensor is so selected as to cancel influence of phase delay when the lateral acceleration sensor is oriented at the position of the neutral gravity sensor.

Claims

1. An actively controlled suspension system for an automotive vehicle, comprising:

a hydraulic cylinder disposed between a vehicle body and a suspension member which rotatably supports a road wheel, said cylinder defining a variable pressure working chamber filled with a pressure medium for generating a damping force resisting relative displacement between said vehicle body and said suspension member, a pressure of said pressure medium being variable between a predetermined maximum value and a predetermined minimum value across a predetermined neutral value, said cylinder being provided for each of the suspension systems respectively associated with said front and rear wheels;

a pressure source circuit means connected to said working chamber for supplying pressure medium and including a pressure source feeding pressurized medium through said circuit;

a pressure control valve disposed between said pressure source and said working chamber and having a valve with a valve position variable between a first mode for increasing pressure of said pressure medium within said working chamber, a second mode for decreasing the pressure in said pressure medium within said working chamber and a third mode for maintaining pressure in said pressure medium constant, said pressure control valve being provided for each of said suspension systems respectively associated with said front and rear wheels;

a lateral acceleration sensor, oriented on the vehicular body at a position frontwardly offset from a center of gravity of the vehicle body for monitoring an acceleration exerted on the vehicle body to cause vehicular attitude change and produce a sensor signal indicative thereof; and

a controller means for receiving said sensor signal for deriving a suspension control signal for operating said pressure control valve at one of said first, second and third mode positions for regulating vehicular attitude on the basis of said sensor signal, said sensor signal including a component created by yawing angular acceleration acting on the vehicle body at the position of the acceleration sensor or a function of the distance of said offset position relative to said center of gravity;

wherein said hydraulic cylinder and said pressure control valve means is provided for each of the suspension systems respectively associated with said front and rear wheels, and said controller means derives said suspension control signal for said pressure control valve means associated with said suspension systems of said front wheels and said rear wheels on the basis of said sensor signal.

2. An actively controlled suspension system as set forth in claim 1, wherein the frontward offset magnitude of said acceleration sensor is derived so as to advance a phase of the control system by a preselected magnitude.

3. An actively controlled suspension system as set forth in claim 2, wherein said frontward offset magnitude of said acceleration sensor relative to the gravity center is derived so that the acceleration sensor is additionally subject to a yawing force in the magnitude advancing a phase of the control system by the preselected magnitude.

4. An actively controlled suspension system for an automotive vehicle, comprising:

a first cylinder oriented one lateral side of a vehicle body and disposed between a vehicle body and a suspension member which rotatably support a road wheel, said cylinder defining a variable pressure working chamber filled with a pressure medium for generating a damping force resisting against relative displacement between said vehicle body and said suspension member, said pressure of said pressure medium being variable between a predetermined maximum value and a predetermined minimum value across a predetermined neutral value;

a second cylinder oriented the other lateral said of said vehicle body and disposed between a vehicle body and a suspension member which rotatably support a road wheel, said cylinder defining variable pressure working chamber filled with a pressure medium for generating a damping force resisting against relative displacement between said vehicle body and said suspension member, said pressure of said pressure medium being variable between a predetermined maximum value and a predetermined minimum value across a predetermined neutral value;

a pressure source circuit means connected to said working chamber for supplying pressure medium and including a pressure source feeding pressurized pressure medium through said circuit;

a pressure control valve disposed between said pressure source and said working chamber of each of said first and second cylinder, and variable of valve position between a first mode for increasing pressure of said pressure medium within said working chamber, a second mode for decreasing pressure in said pressure within said working source, and a third mode for maintaining said pressure in said pressure medium constant;

an acceleration sensor, oriented on the vehicular body at a position frontwardly offset from a gravity center of the vehicular body, for monitoring an acceleration exerted on the vehicle body to cause vehicular attitude change and producing a sensor signal indicative thereof;

a controller means for receiving said sensor signal for deriving a first and second suspension control signals for operating said pressure control valve of respective first and second cylinders at one of said first, second and third mode positions for regulating vehicular attitude on the basis of said sensor signal, said first and second suspension control signals having equal magnitude and opposite polarities with respect to each other, wherein said hydraulic cylinder is provided for each of the suspension systems respectively associated with said front and rear wheels, said controller means receiving the acceleration sensor signal indicating lateral acceleration including a component created by yawing angular acceleration acting on the vehicle body at the position of the acceleration sensor, the component being variable dependent upon the distance of said oriented position relative to said center of gravity and advancing a phase of the control system by a preselected magnitude in anti-rolling control.

5. An actively controlled suspension system as set forth in claim 4, wherein said hydraulic cylinder and said pressure control valve means is provided for each of suspension systems respectively associated with said front and rear wheels, and said controller means derives said suspension control signal for said pressure control valve means associated with said suspension systems of said front wheels and said rear wheels on the basis of said sensor signal.

6. An actively controlled suspension system as set forth in claim 5, wherein said acceleration sensor comprises a lateral acceleration sensor.

7. An actively controlled suspension system as set forth in claim 6, wherein the frontward offset magnitude of said acceleration sensor is derived so as to compensate phase delay of control system.

8. An actively controlled suspension system as set forth in claim 7, wherein said frontward offset magnitude of said acceleration sensor relative to the gravity center is derived so that the acceleration sensor is additionally subject yawing force in a magnitude compensating said phase delay.

9. An actively controlled suspension system for an automotive vehicle, comprising:

a cylinder disposed between a vehicle body and a suspension member which rotatably supports a road wheel, said cylinder defining a variable pressure working chamber filled with a pressure medium for generating a damping force resisting against relative displacement between said vehicle body and said suspension member, said pressure of said pressure medium being variable between a predetermined maximum value and a predetermined minimum value across a predetermined neutral value;

a pressure source circuit means connected to said working chamber for supplying pressure medium and including a pressure source feeding pressurized pressure medium through said circuit;

a pressure control valve disposed between said pressure source and said working chamber and having a valve whose position is variable between a first mode for increasing pressure of said pressure medium within said working chamber, a second mode for decreasing pressure in said pressure within said working source and a third mode for maintaining said pressure in said pressure medium constant;

an acceleration sensor means for monitoring a lateral acceleration exerted on the vehicle body to cause vehicular attitude change and produce a sensor signal indicative thereof, said acceleration sensor being oriented at a position offset forwardly from the gravity center of the vehicle, the offset magnitude being so determined as to set a monitoring point at which lateral acceleration is to be monitored to add a component created by yawing angular acceleration acting on the vehicle body at the monitoring point to the sensor signal for advancing a phase in said pressure source circuit and said pressure control valve by a preselected magnitude; and

a controller means for receiving said sensor signal for deriving a suspension control signal for operating said pressure control valve at one of said first, second and third mode positions for regulating vehicular attitude on the basis of said sensor signal.