Appeal No. 2003-0405 Page 9
Application No. 09/635,183
brake torques over time during a typical brake pedal application. Curve 130
describes the requested total brake torque, which is to be made up of
regenerative torque to the degree possible, represented by curve 133, and
friction brake torque, represented by curve 136. Thus, the system must calculate,
at any time, the friction brake torque required, when added to the regenerative
torque achieved, to produce the total requested brake torque. It can be seen that
there is a delay in the achievement of regenerative torque, so that the initial
braking is almost all by the friction brake system. When regenerative braking is
finally achieved, it quickly goes to its achieved level, which results in a temporary
significant reduction in friction brake torque. When the achieved regenerative
torque reaches its achieved level and flattens out, there is an additional increase
in friction brake torque before it levels out also. At any time, however, the sum of
the values of curves 133 and 136 should equal the value of curve 130. In the
event of anti-lock brake activity, this system will ramp down the regenerative
blended brake torque, as shown with respect to curve 133 starting with the ABS
event indicated. As this ramp down occurs, of course, the friction brakes, which
will be under the control of the anti-lock brake system, will make up the
difference in total brake torque, as shown. Returning to the flow chart of FIG. 5,
the FRONT BRAKE FRICTION TORQUE signal is finally output to actuators 114
and 116 to apply friction braking to front wheels 24 and 26.
The appellants argue (brief, pp. 9-11; reply brief, pp. 3-4) that Kidston teaches
completely eliminating the torque that is being applied to the drivetrain as regenerative
braking torque when a wheel-condition-initiated triggering event occurs and therefore
does not teach the following:
(1) the processing system executing "a strategy comprising reducing, but not
completely eliminating, the torque that is being applied to the drivetrain as regenerative
braking torque when a wheel-condition-initiated triggering event occurs" as recited in
claim 2;
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Last modified: November 3, 2007