Method and apparatus for maintaining vehicular ride height
First Claim
1. A method for controlling vehicle ride height for use with a vehicle travelling on a road surface, the vehicle having a body, front and rear wheels and an air suspension, the method comprising:
- (a) sensing vehicle body height relative to the wheels to obtain front and rear vehicle height signals, and sensing vehicle speed to obtain a vehicle speed signal;
(b) determining a natural lean of the vehicle based on the front height signals, natural lean of the vehicle representative of one side of the vehicle being higher or lower than the other side of the vehicle;
(c) processing the front height signals to obtain a vehicle roll signal that has been compensated for the natural lean of the vehicle, the vehicle roll signal indicating vehicle roll due to steering adjustments by the vehicle operator;
(d) processing the vehicle speed signal to obtain a vehicle pitch offset signal, the vehicle pitch offset signal indicating vehicle height change due to longitudinal vehicle accelerations; and
(e) adjusting the height of the vehicle toward a predetermined target ride height based on the height signals, the vehicle roll signal and the vehicle pitch offset signal.
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Accused Products
Abstract
Method and apparatus for maintaining vehicular ride height in a vehicle having a body, front and rear wheels and an air suspension including front and rear air springs. The method includes sensing vehicle body height relative to the wheels to obtain front and rear vehicle height signals, and sensing vehicle speed to obtain a vehicle speed signal. The method also includes processing the front height signals to obtain a vehicle roll signal that has been compensated for the natural lean of the vehicle, the vehicle roll signal indicating vehicle roll due to steering adjustments by the vehicle operator. The method further includes processing the vehicle speed signal to obtain a vehicle pitch offset signal, indicating vehicle body height change due to longitudinal vehicle acceleration. The method also includes adjusting the height of the vehicle toward a predetermined target ride height based on the vehicle height sensor signals which have been compensated for vehicle roll and pitch.
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Citations
19 Claims
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1. A method for controlling vehicle ride height for use with a vehicle travelling on a road surface, the vehicle having a body, front and rear wheels and an air suspension, the method comprising:
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(a) sensing vehicle body height relative to the wheels to obtain front and rear vehicle height signals, and sensing vehicle speed to obtain a vehicle speed signal; (b) determining a natural lean of the vehicle based on the front height signals, natural lean of the vehicle representative of one side of the vehicle being higher or lower than the other side of the vehicle; (c) processing the front height signals to obtain a vehicle roll signal that has been compensated for the natural lean of the vehicle, the vehicle roll signal indicating vehicle roll due to steering adjustments by the vehicle operator; (d) processing the vehicle speed signal to obtain a vehicle pitch offset signal, the vehicle pitch offset signal indicating vehicle height change due to longitudinal vehicle accelerations; and (e) adjusting the height of the vehicle toward a predetermined target ride height based on the height signals, the vehicle roll signal and the vehicle pitch offset signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 15)
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10. A method for controlling vehicle ride height for use with a vehicle travelling on a road surface, the vehicle having a body, front and rear wheels and an air suspension, the method comprising:
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(a) sensing vehicle body height relative to the wheels to obtain front and rear vehicle height signals, and sensing vehicle speed to obtain a vehicle speed signal; (b) determining a natural lean of the vehicle based on the front height signals, the natural lean of the vehicle representative of one side of the vehicle being higher or lower than the other side of the vehicle; (c) filtering the vehicle height signals to remove road inputs due to variations in the road surface to obtain filtered height signals, the filtered height signals lagging the vehicle height signals; (d) processing the front height signals to obtain a vehicle roll signal that has been compensated for the natural lean of the vehicle, the vehicle roll signal indicating vehicle roll due to steering adjustments by the vehicle operator; (e) processing the vehicle speed signal to obtain a vehicle pitch offset signal, the vehicle pitch offset signal indicating vehicle height change due to vehicle longitudinal accelerations; (f) determining an adjusted vehicle height signal based on the filtered height signals, the vehicle roll signal and the pitch offset signal; (g) compensating the adjusted vehicle height signal for the filtering lag introduced by step (c), to obtain a compensated height signal indicating the actual change in vehicle ride height; and (h) adjusting the height of the vehicle toward a predetermined target ride height based on the compensated height signal, thereby increasing the speed and accuracy with which vehicle ride height adjustments are made. - View Dependent Claims (11, 12, 13, 14, 16)
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17. An apparatus for controlling vehicle ride height for use with a vehicle travelling on a road surface, the vehicle having a body, front and rear wheels and an air suspension, the apparatus comprising:
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means for sensing vehicle body height relative to the wheels to obtain front and rear vehicle height signals, and sensing vehicle speed to obtain a vehicle speed signal; means for determining a natural lean of the vehicle based on the front height signals, the natural lean of the vehicle representative of one side of the vehicle being higher or lower than the other side of the vehicle; low pass filter means for filtering the vehicle height signals to remove road inputs due to variations in the road surface to obtain filtered height signals, the filtered height signals lagging the vehicle height signals; filter means for processing the front height signals to obtain a vehicle roll signal that has been compensated for the natural lean of the vehicle, the vehicle roll signal indicating vehicle roll due to steering adjustments by the vehicle operator; filter means for processing the vehicle speed signal to obtain a vehicle pitch offset signal, the vehicle pitch offset signal indicating vehicle height change due to vehicle longitudinal accelerations; means for determining an adjusted vehicle height signal based on the filtered height signals, the vehicle roll signal and the pitch offset signal; means for compensating the adjusted vehicle height signal for filtering lag introduced by the low pass filter means, to obtain a compensated height signal indicating the actual change in vehicle ride height; and means for adjusting the height of the vehicle toward a predetermined target ride height based on the compensated height signal, thereby increasing the speed and accuracy with which vehicle ride height adjustments are made. - View Dependent Claims (18, 19)
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Specification