Vehicle braking force controller

• US 5,772,289 A
• Filed: 08/30/1995
• Issued: 06/30/1998
• Est. Priority Date: 10/11/1994
• Status: Expired due to Term

• Current Assignee: Nissan Diesel Company Limited
• Original Assignee: Nissan Diesel Company Limited
• Inventors: Nakazawa, Masao, Notsu, Ikurou, Isobe, Osamu, Takahashi, Sadahiro
• Primary Examiner(s): OBERLEITNER, ROBERT J
• Application Number:
  US08/521,536
• Time in Patent Office: 1,035 Days
• Field of Search: 303/9.69, 303/123, 303/146, 303/147, 303/181-183, 303/198, 303/155, 303/191, 303/22.1, 303/22.2, 364/462.02, 364/463, 364/426.024, 364/426.026, 188/195
• US Class Current: 303/9.69
• CPC Class Codes: B60T 8/00 Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force by changing number of effective brake cylinders in power brake systems B60T17/10
• CPC Class Codes: B60T 8/1766 Proportioning of brake forces according to vehicle axle loads, e.g. front to rear of vehicle
• CPC Class Codes: B60T 8/18 responsive to vehicle weight or load, e.g. load distribution using electrical circuitry on regulation means B60T8/17; B60T8/30 takes precedence; responsive to weight and speed condition B60T8/58
• CPC Class Codes: B60T 8/266 using valves or actuators with external control means B60T8/261 takes precedence

Abstract

In an apparatus for controlling the braking force applied to the wheels of a vehicle, the braking force required for the vehicle is calculated according to a brake pedal depression amount and the weight of the vehicle. This braking force is allocated to the wheels, according to static loads acting on the wheels which vary according to the vehicle loading conditions. Alternatively, the forward/backward acceleration of the vehicle and sideway acceleration of the front and rear axles are detected, dynamic loads acting on the wheels are calculated from the static loads and these accelerations, and the braking force is allocated according to these dynamic loads. Preferably, the roll angles of the front and rear axles are respectively detected, and the detected sideways accelerations are corrected based on these angles. By way this braking force control, braking force can be optimized according to the loading conditions in commercial vehicles, such as trucks, where wheel load conditions largely vary.

Claims

1. A braking force controller for a vehicle, said vehicle having a front axle and a rear axle each of which supports wheels, comprising:

a brake pedal,

means for detecting a depression amount of said brake pedal,

means for setting a static load on each of said wheels,

means for computing a target vehicle deceleration from a sum of said static loads on said wheels and said depression amount,

means for calculating a vehicle braking force required to obtain said target deceleration,

means for allocating said vehicle braking force to each of said wheels based on said static load on each of said wheels, and

means for respectively applying a braking force allocated by said allocating means to each of said wheels.

2. A braking force controller as defined in claim 1, wherein said static load setting means comprises sensor means for detecting a static load acting on each of said wheels.

3. A braking force controller as defined in claim 1, wherein said static load setting means comprises means for inputting a vehicle loading condition and means for setting said static load on each of said wheels according to said condition.

4. A braking force controller for a vehicle, said vehicle having a front axle that supports front wheels and a rear axle each that supports rear wheels, comprising:

a brake pedal,

means for detecting a depression amount of said brake pedal,

means for setting a static load on each of said front and rear wheels,

means for computing a target vehicle deceleration from a sum of said static loads on said front and rear wheels and said depression amount,

means for calculating a vehicle braking force required to obtain said target deceleration,

means for detecting a sideway acceleration of said front axle,

means for detecting a sideway acceleration of said rear axle,

means for calculating a dynamic load on each of said front wheels from said static load on each of said front wheels and the sideway acceleration of said front axle,

means for calculating a dynamic load on each of said rear wheels from said static load on each of said rear wheels and the sideway acceleration of said rear axle,

means for allocating said vehicle braking force to each of said front and rear wheels based on said dynamic load on each of said front and rear wheels, and

means for respectively applying a braking force allocated by said allocating means to each of said front and rear wheels.

5. A braking force controller as defined in claim 4, wherein said static load setting means comprises sensor means for detecting a static load acting on each of said front and rear wheels.

6. A braking force controller as defined in claim 4, wherein said static load setting means comprises means for inputting a vehicle loading condition and means for setting said static load on each of said front and rear wheels according to said loading condition.

7. A braking force controller for a vehicle, said vehicle having a front axle that supports front wheels and a brake pedal, and a rear axle that supports rear wheels and a brake pedal, comprising:

means for detecting a depression amount of said brake pedal,

means for setting a static load on each of said front and rear wheels,

means for computing a target vehicle deceleration from a sum of said static loads on said front and rear wheels and said depression amount,

means for calculating a vehicle braking force required to obtain said target deceleration,

means for detecting a sideway acceleration of said front axle,

means for detecting a sideway acceleration of said rear axle,

means for detecting a roll angle of said front axle,

means for detecting a roll angle of said rear axle,

means for correcting said sideway acceleration of said front axle according to said roll angle of said front axle,

means for correcting said sideway acceleration of said rear axle according to said roll angle of said rear axle,

means for calculating a dynamic load on each of said front wheels from said static load on each of said front wheels and a corrected sideway acceleration of said front axle corrected by said front axle sideway acceleration correcting means,

means for calculating a dynamic load on each of said rear wheels from said static load on each of said rear wheels and a corrected sideway acceleration of said rear axle corrected by said rear axle sideway acceleration correcting means,

means for allocating said vehicle braking force to each of said front and rear wheels based on said dynamic load on each of said front and rear wheels, and

means for respectively applying a braking force allocated by said allocating means to each of said front and rear wheels.

8. A braking force controller as defined in claim 7, wherein said front axle roll angle detecting means comprises means for detecting a contraction amount of a suspension that supports each of said front wheels on said front axle, and said rear axle roll angle detecting means comprises means for detecting a contraction amount of a suspension that supports each of said rear wheels on said rear axle.

9. A braking force controller for a vehicle, said vehicle having a front axle that supports front wheels and a rear axle that supports rear wheels and a brake pedal, comprising:

means for detecting a depression amount of said brake pedal,

means for setting a static load on each of said front and rear wheels,

means for computing a target vehicle deceleration from a sum of said static loads on said front and rear wheels and said depression amount,

means for calculating a vehicle braking force required to obtain said target deceleration,

means for detecting a forward/backward acceleration of said vehicle,

means for detecting a sideway acceleration of said front axle,

means for detecting a sideway acceleration of said rear axle,

means for detecting a pitch angle of said vehicle,

means for detecting a roll angle of said front axle,

means for detecting a roll angle of said rear axle,

means for correcting said forward/backward acceleration according to said pitch angle,

means for correcting said sideway acceleration of said front axle according to said roll angle of said front axle,

means for correcting said sideway acceleration of said rear axle according to said roll angle of said rear axle,

means for calculating a dynamic load on each of said front wheels from said static load on each of said front wheels, a corrected forward/backward acceleration corrected by said forward/backward acceleration correcting means, and a corrected sideway acceleration of said front axle corrected by said front axle sideway acceleration correcting means,

means for calculating a dynamic load on each of said rear wheels from said static load on each of said rear wheels, said corrected forward/backward acceleration, and a corrected sideway acceleration of said rear axle corrected by said rear axle sideway acceleration correcting means,

means for allocating said vehicle braking force to each of said front and rear wheels based on said dynamic load on each of said front and rear wheels, and

means for respectively applying a braking force allocated by said allocating means to each of said front and rear wheels.