Road surface condition detecting and anti-skid controlling device in car

• US 4,984,163 A
• Filed: 07/31/1989
• Issued: 01/08/1991
• Est. Priority Date: 07/29/1988
• Status: Expired due to Term

• Current Assignee: Aisin Seiki Co., Ltd. (Aisin Corp.)
• Original Assignee: Aisin Seiki Co., Ltd. (Aisin Corp.)
• Inventors: Yoshida, Tsuyoshi, Tozu, Kenji, Kuwana, Kazutaka
• Primary Examiner(s): Chin, Gary
• Application Number:
  US07/386,781
• Time in Patent Office: 526 Days
• Field of Search: 364/424.05, 364/426.02, 364/550, 364/551.01, 280/707, 303/95, 303/103, 73/105
• US Class Current: 701/80
• CPC Class Codes: B60G 17/0165 to an external condition, e.g. rough road surface, side wind
• CPC Class Codes: B60G 17/0195 characterised by the regulation being combined with other vehicle control systems conjoint control of vehicle sub-units including control of suspension systems B60W10/22
• CPC Class Codes: B60G 2202/154 with an accumulator
• CPC Class Codes: B60G 2202/24 Fluid damper
• CPC Class Codes: B60G 2400/106 longitudinal with regard to vehicle, e.g. braking
• 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 2400/304 neutral position
• CPC Class Codes: B60G 2400/33 Throttle position
• CPC Class Codes: B60G 2400/41 Steering angle
• CPC Class Codes: B60G 2400/50 Pressure
• CPC Class Codes: B60G 2400/82 Ground surface
• CPC Class Codes: B60G 2400/821 Uneven, rough road sensing affecting vehicle body vibration
• CPC Class Codes: B60G 2400/90 Other conditions or factors
• CPC Class Codes: B60G 2400/91 Frequency
• CPC Class Codes: B60G 2400/952 of door or bonnet
• CPC Class Codes: B60G 2401/172 Hall effect
• CPC Class Codes: B60G 2500/22 Spring constant
• CPC Class Codes: B60G 2500/30 Height or ground clearance
• CPC Class Codes: B60G 2600/04 : Means for informing, instructing or displaying
• 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 2600/20 : Manual control or setting means
• CPC Class Codes: B60G 2600/70 : Computer memory; Data storage, e.g. maps for adaptive control
• CPC Class Codes: B60T 2210/12 : Friction
• CPC Class Codes: B60T 2210/14 : Rough roads, bad roads, gravel roads
• CPC Class Codes: B60T 2270/208 : adapted to friction condition
• CPC Class Codes: B60T 8/172 : Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: B60T 8/175 : Brake regulation specially adapted to prevent excessive wheel spin during vehicle acceleration, e.g. for traction control safety devices for propulsion unit control responsive to, or preventing, skidding of wheels B60K28/16
• CPC Class Codes: B60T 8/17616 : Microprocessor-based systems

Abstract

A road surface condition detecting and anti-skid controlling device in a car capable of detecting the road surface condition with high accuracy in a multiple-step manner, so that brake pressure control and attenuating capacity adjustment of shock absorbers as well as car level adjustment are more effectively executed. The invention is includes: car wheel speed and car speed detecting devices, a speed changing rate detecting device, memory, valve, calculating, integrating, and comparing devices, and a brake pressure control device. According to the invention, the road surface condition is detected with high accuracy and anti-skid control is more effectively executed by pertinent brake pressure control in response to the road condition so that a high degree of safety and reliability for the brake control in car can be obtained.

Claims

1. A road surface condition detecting device in a car comprising:

car wheel rotational speed detecting means for detecting the rotational speed of a car wheel of said car;

changing rate detecting means for detecting a speed changing rate of the car wheel rotational speed detected with said car wheel rotational speed detecting means;

integrating means for integrating an absolute value of the speed changing rate detected with said changing rate detecting means; and

comparing means for comparing an integrated value from said integrating means with a set value for road surface condition judgment to thereby detect a road surface condition.

2. A road surface condition detecting device in a car comprising:

car wheel rotational speed detecting means for detecting rotational speed of a car wheel of said car;

changing rate detecting means for detecting a speed changing rate of the car wheel rotational speed detected with said car wheel rotational speed detecting means;

integrating means for integrating an absolute value of the speed changing rate detected with said changing rate detecting means;

car speed detecting means for detecting car speed;

speed comparing means for comparing said car wheel rotation speed with said car speed;

judgment comparing means for comparing an integrated value of said integrating means with a set value for road surface condition judgment to thereby detect a road surface condition; and

memory means for storing judgment information of said judgment comparing means at a time when said speed comparing means detects that said car wheel rotational speed is within a range of being substantially equal to said car speed.

3. Anti-skid control device comprising:

a brake pressure source for generating a high pressure and a low pressure;

valve means which is interposed between said brake pressure source and a car wheel brake, for connecting a liquid flow path between said car wheel brake and said high pressure and low pressure of said brake pressure source;

car wheel rotation speed detecting means for detecting rotational speed of a car wheel equipped with said car wheel brake;

calculating means for calculating car speed on the basis of said car wheel rotation speed;

means for calculating a speed changing rate of said car wheel rotation speed;

integrating means for integrating an absolute value of the speed changing rate;

comparing means for comparing an integrated value of said integrating means with a set value for road surface condition judgment; and

brake pressure control means for controlling low pressure/high pressure connection of said car wheel brake by driving said valve means in response to a compared result of said car wheel rotation speed and said car speed and said comparing means.