Data processing: vehicles – navigation – and relative location – Vehicle control – guidance – operation – or indication – Indication or control of braking – acceleration – or deceleration
Reexamination Certificate
1999-12-03
2001-01-16
Cuchlinski, Jr., William A (Department: 3661)
Data processing: vehicles, navigation, and relative location
Vehicle control, guidance, operation, or indication
Indication or control of braking, acceleration, or deceleration
C701S071000, C701S077000
Reexamination Certificate
active
06175798
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates in general to anti-lock brake systems and in particular an algorithm for verification that the anti-lock brake system control module installed in a particular vehicle corresponds to the configuration of the vehicle drive train.
An Anti-lock Brake System (ABS) is often included as standard or optional equipment on new vehicles. When actuated, the ABS is operative to control the operation of some or all of the vehicle wheel brakes. A typical ABS includes a plurality of solenoid valves mounted within a control valve and connected to the vehicle hydraulic brake system. Usually, a separate hydraulic source, such as a motor driven pump, is included in the ABS for reapplying hydraulic pressure to the controlled wheel brakes during an ABS braking cycle. An ABS further includes an electronic control module which is electrically connected to wheel speed sensors mounted adjacent to the controlled wheels, the solenoid valves and pump motor. The control module can be mounted directly upon the control valve or located remotely therefrom. The control module includes a microprocessor, or ABS controller, which is programmed to control the ABS in accordance with a control algorithm and parameters permanently stored in a Read Only Memory (ROM). The microprocessor also can access a Random Access Memory (RAM) for temporary storage and retrieval of data.
During vehicle operation, the microprocessor in the ABS control module continuously receives speed signals from the wheel speed sensors. The microprocessor monitors the speed signals for potential wheel lock-up conditions. When the vehicle brakes are applied and the microprocessor senses an impending wheel lock-up condition, the microprocessor is responsive thereto to close a power relay. The power relay controls the supply of electric power to enable the solenoid valves and actuate the pump motor. The microprocessor selectively actuates the solenoid valves in the control valve in accordance with the control algorithm stored in the ROM to cyclically relieve and reapply hydraulic pressure to the controlled wheel brakes. The hydraulic pressure applied to the controlled wheel brakes is adjusted by the operation of the solenoid valves to limit wheel slippage to a safe level while continuing to is produce adequate brake torque to decelerate the vehicle.
SUMMARY OF THE INVENTION
This invention relates to an algorithm for verification that the anti-lock brake system control module installed in a particular vehicle corresponds to the configuration of the vehicle drive train.
The majority of four wheeled vehicles have either the two front or two rear wheels powered. Such two wheel drive (2WD) vehicles are commonly referred to as having a 4×2 drive train. The ABS control module associated with a 4×2 vehicle drive train includes a 4×2 algorithm which provides optimal braking during an ABS brake cycle. However, inclusion of drive trains for powering all four wheels in vehicles has become increasingly popular. Such four wheel drive (4WD) vehicles, which are commonly referred to as having a 4×4 drive train, normally operate in a two wheel drive mode and include a transfer case which, upon selection by the vehicle operator, couples the normally nondriven wheels to the vehicle engine. When all four vehicle wheels are driven, a different ABS brake response is required to assure optimal braking during an ABS brake cycle. Accordingly, the ABS control module installed in a vehicle having four wheel drive has a 4×4 control algorithm which provides a brake response corresponding to the operational mode of the vehicle.
In order to minimize manufacturing and inventory costs while providing uniform installation connections, the same hardware is utilized for both 4×2 and 4×4 vehicles. Specific software which includes an ABS control algorithm customized for the particular vehicle drive train is loaded into the ABS control module. It would be desirable to verify that the installed software corresponds to the vehicle drive train. Additionally, it would be desirable to prevent operation of a mismatched ABS control algorithm if the control module has been incorrectly installed, as could happen if the module has been obtained from a used parts dealer.
The present invention contemplates a controller for an anti-lock brake system which includes a microprocessor adapted to operate the anti-lock brake system. The microprocessor includes a status port adapted to be connected to a four wheel drive transfer case. The controller also includes a verification algorithm for the microprocessor with the algorithm being responsive to a condition at the status port to prevent said microprocessor from operating the anti-lock brake system. The algorithm is further responsive to the condition to cause the microprocessor to generate an alarm signal.
The algorithm can be responsive to the status port being connected to ground or to a constant voltage being applied thereto to prevent the microprocessor from operating the anti-lock brake system. The algorithm also can be responsive to a varying status signal being applied to said status port to prevent said microprocessor from operating the anti-lock brake system. In the preferred embodiment, the algorithm is responsive to the frequency of the status signal being outside of a predetermined frequency range to prevent the microprocessor from operating the anti-lock brake system.
Alternately, the controller status port can be adapted to be connected to a source of a predetermined voltage or to ground. In the former case, upon detection of a zero voltage or a variable voltage having a frequency, the algorithm is operative to prevent the microprocessor from operating the anti-lock brake system. In the later case, upon detection of a non-zero voltage or a variable voltage having a frequency, the algorithm is operative to prevent the microprocessor from operating the anti-lock brake system.
Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.
REFERENCES:
patent: 5138556 (1992-08-01), Yoshino
patent: 5277482 (1994-01-01), Beyer et al.
patent: 5490072 (1996-02-01), Hornback
patent: 5492396 (1996-02-01), Weber
patent: 5493495 (1996-02-01), Naito et al.
patent: 5612880 (1997-03-01), Kojima et al.
patent: 5941612 (1999-08-01), Carpenter
Cuchlinski, Jr. William A
Kelsey-Hayes Company
MacMillan Sobanski & Todd LLC
Marc-Coleman Marthe
LandOfFree
Algorithm for verification of correct ABS controller... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Algorithm for verification of correct ABS controller..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Algorithm for verification of correct ABS controller... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2474825