Data processing: vehicles – navigation – and relative location – Vehicle control – guidance – operation – or indication – Indication or control of braking – acceleration – or deceleration
Reexamination Certificate
2000-03-08
2002-08-20
Arthur, Gertrude (Department: 3661)
Data processing: vehicles, navigation, and relative location
Vehicle control, guidance, operation, or indication
Indication or control of braking, acceleration, or deceleration
C701S078000, C701S079000, C303S122060
Reexamination Certificate
active
06438481
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates in general to a method of selecting a trim set for a control system algorithm, and in particular, selecting a performance trim set for a vehicle control system which corresponds to a particular vehicle from a plurality of trim sets.
Many new vehicles include systems for controlling the braking of the individual wheels. Such systems can include an anti-lock braking capability to prevent wheel lock up during sudden stops and/or a traction control capability to prevent driven wheels from slipping upon low mu road surfaces. Recently, control systems have been further developed to enhance the stability of a moving vehicle.
Referring now to the drawings, there is illustrated in
FIG. 1
typical brake control system
10
. The system
10
is intended to be exemplary and it will be appreciated that there are other brake control systems having more or less components. In
FIG. 1
, hydraulic brake lines are shown as solid lines while electrical connections are shown as dashed lines. While single dashed lines are shown, it will be understood that the lines can represent a plurality of individual wires or a data buss. Additionally, mechanical connections are shown by dotted lines.
The system
10
shown is for a front wheel drive vehicle having a pair of front wheels
11
driven through a transaxle
12
by a transversely mounted engine
13
. The transaxle
12
and engine
13
both include a microprocessor,
14
and
15
, respectively for controlling the unit. Both front wheels
11
have associated front wheel brakes
16
which are connected though a pair of normally open solenoid actuated front isolation valves
18
to the front reservoir of a dual reservoir master cylinder
20
. A pair of solenoid operated front dump valves
22
are connected to the hydraulic lines between the front wheel brakes
16
and the isolation valves
18
. The front dump valves
22
are operable to bleed hydraulic fluid from the front wheel brakes
16
to an front wheel brake accumulator
24
and to an input port of a front wheel brake pump
26
. The discharge of the front pump
26
is connected through a pair of check valves
28
and dump valves
22
to the front wheel brakes
16
.
The rear reservoir of the master cylinder
20
is connected through a single rear isolation valve
30
and a single rear dump valve
32
to the wheel brakes
34
associated with the vehicle rear wheels
35
. The rear dump valve
32
is operable to bleed hydraulic fluid from the rear wheel brakes
34
to an rear wheel brake accumulator
36
and to an input port of a rear wheel brake pump
38
. The discharge of the rear pump
38
is connected through a check valve
40
and the rear dump valve
32
to the rear wheel brakes
34
. Both the front and rear pumps
26
and
38
are driven by a common electric motor
42
.
Usually the solenoid valves
18
,
22
,
32
and
36
are mounted within a control valve body (not shown). The pumps
26
and
38
also are included within the control valve body while the pump motor
42
is mounted upon the exterior of the control valve body.
The brake control system
10
further includes an Electronic Control Unit (ECU)
44
which has a microprocessor
45
. The ECU
44
receives electric power through a vehicle ignition switch
46
. The ECU
44
is electrically coupled to the pump motor
42
, the solenoid valve coils associated with the solenoid valves
18
,
22
,
30
and
32
and a plurality of wheel speed sensors
47
for monitoring the speed and deceleration of the controlled wheels. The ECU
44
may also be connected to acceleration sensors
48
mounted upon directly upon the vehicle. The ECU
44
is typically mounted upon the control valve body to form a compact unit which is often referred to as an electro-hydraulic control unit.
For an Anti-Lock Bake System (ABS), the microprocessor
45
in the ECU
44
continuously receives speed signals from the wheel speed sensors
47
and any acceleration sensors
48
. The microprocessor
45
monitors the wheel speed signals for a potential wheel lock-up condition. When the vehicle brakes are applied and the microprocessor
45
senses an impending wheel lock-up condition, the microprocessor
45
is operative to actuate the pump motor
42
and selectively operate the solenoid valves
18
,
22
,
30
and
32
to cyclically relieve and reapply hydraulic pressure to the controlled wheel brakes
16
and
34
. The hydraulic pressure applied to the controlled wheel brakes
16
and
34
is adjusted by the operation of the solenoid valves
18
,
22
,
30
and
32
to limit wheel slippage to a safe level while continuing to produce adequate brake torque to decelerate the vehicle as desired by the driver. For traction control, the brakes are applied to the driven wheels
11
to assure that the wheel does not begin spinning on a low mu surface. Some traction control systems also communicate with the engine control microprocessor
14
to reduce engine speed and/or torque upon sensing wheel slippage. Finally, for stability control, the wheel brakes
16
and
34
are selectively actuated to maintain the vehicle upon a desired course.
A control algorithm is stored in a Read Only Memory (ROM)
49
for the microprocessor
45
in the ECU
44
. The control algorithm includes the formulas and threshold values utilized by the microprocessor
45
when the control system is actuated. While a single control algorithm can be used for a variety of vehicles, the threshold values and constants loaded into the algorithm need to be selected to correspond to characteristics of the particular vehicle. Such vehicle characteristics include the vehicle weight, braking capacity, engine size, transaxle characteristics, ect. The threshold values and constants which are loaded into the control algorithm are commonly referred to as a performance trim set for the algorithm.
Typically, a specific performance trim set for a vehicle requires programming in a programmable memory, such as an Erasable Programmable Read Only Memory (EPROM), during production of the control module or when the control module is delivered to the customer. As indicated above, the trim set may provide target information for a vehicle control system, such as, a Traction Control System (TCS), a Vehicle Stability Control (VSC), and an Anti-Lock Braking System (ABS), and the like. After programming the electronic control module, the trim set would be used for the lifetime of the ECU
44
and would be valid as long as the vehicle configuration remains constant.
SUMMARY OF THE INVENTION
This invention relates to selecting a performance trim set for a vehicle control system which corresponds to a particular vehicle from a plurality of trim sets.
As described above, a performance trim set corresponding to a particular vehicle is loaded into an electronic control module. Once loaded, the trim set is fixed. Should the control module be installed in a different vehicle or a vehicle component, such as the engine and/or transaxle or transmission be changed, the algorithm would no longer be trimmed for optimal operation of the brake control system. Accordingly, it would be desirable to provide a method for matching the performance trim set to the particular vehicle components associated with the vehicle in which the control module is installed.
The present invention contemplates a method of selecting a trim set for a vehicle control system algorithm from a plurality of trim sets which includes determining a parameter related to at least one vehicle component. A trim set corresponding to the parameter is then selected and loaded into the vehicle control system algorithm.
The method also includes comparing the determined parameter to a set of allowable parameters and loading the corresponding trim set only upon the parameter being included in the set of allowable parameters. If the parameter is not included in the set of allowable parameters, an error flag is set and the control system is disabled.
The method includes sending an interrogatory message over a vehicle communication bus to the vehicle c
Carpenter Jeffrey M.
Dumm Bernard
Gillipsie Richard
Jacobs John
Priemer Douglas
Arthur Gertrude
Kelsey-Hayes Company
MacMillan Sobanski & Todd LLC
LandOfFree
Selectable trims for a control system algorithm does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Selectable trims for a control system algorithm, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Selectable trims for a control system algorithm will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2935045