US4733875A
Expired / Lapsed
US
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Vehicle height control apparatus
Assignee: Honda Motor Co Ltd
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Filing: 1986-04-21
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Granted: 1988-03-29
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Expires: 2006-04-21
Abstract
Abstract A vehicle height control device that includes a pressure sensor 28 for detecting the pressure of compressed air supplied to pneumatic shock absorbers 10 for pneumatically bearing the load of a vehicle loads applied through the wheels. A control circuit 30 is included for controlling vehicle height based on the pressure detected by the pressure sensor 28. A waveform shaping circuit is connected between the control circuit 30 and the pressure sensor 28 and shapes the waveform to moderate the pressure change while the pressure is rising to a greater degree than while the pressure is dropping. The waveform shaping circuit includes a passive low-pass filter circuit 38, an active low-pass filter circuit 52 and a pair of diodes 70 and 72. The diodes 70 and 72 connected to the active filter circuit 52, allowing rapid capacitor discharge during decreases in signal amplitude while maintaining a slow discharge rate during decreases in signal amplitude.
Inventors
- 👤 Toshiyuki Azuma
- 👤 Seiji Yamashita
- 👤 Koichi Hikichi
- 👤 Morio Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:59
CPC Classifications
B; B60; B60G; B60G17/00; B60G17/015; B60G17/018
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
137 words
A vehicle height control apparatus, receiving a vehicle height signal and controlling height using a pressurized fluid, said apparatus comprising: pressure sensing means for producing a pressure signal waveform in dependence upon fluid pressure; pressure signal compression means for amplitude compressing a rising portion of the pressure signal waveform more than a falling portion of the pressure signal waveform, a time constant of the falling portion of said pressure signal waveform being shorter than a time constant of the rising portion of said pressure signal waveform, causing the pressure to increase by a first speed during the rising portion and causing the pressure to decrease by a second speed faster than said first speed during the falling portion; and height control means for controlling vehicle height in dependence upon the compressed waveform and the vehicle height signal.
Claim 2
Dependent Claim
137 words
A vehicle height control apparatus, receiving a vehicle height signal and controlling height using a pressurized fluid, said apparatus comprising: pressure sensing means for producing a pressure signal waveform in dependence upon fluid pressure; pressure signal compression means for amplitude compressing a rising portion of the pressure signal waveform more than a falling portion of the pressure signal waveform, a time constant of the falling portion of said pressure signal waveform being shorter than a time constant of the rising portion of said pressure signal waveform, causing the pressure to increase by a first speed during the rising portion and causing the pressure to decrease by a second speed faster than said first speed during the falling portion; and height control means for controlling vehicle height in dependence upon the compressed waveform and the vehicle height signal.
Claim 3
Dependent Claim
149 words
A vehicle height control apparatus receiving a vehicle height signal, comprising: height adjustment means for adjusting vehicle height using a pressurized fluid; pressure sensing means for sensing the pressure of the pressurized fluid and producing a pressure signal having rising and falling portions each having a slope; waveform shaping means for smoothing the pressure signal by decreasing the slope of the rising portion more than the slope of the falling portion, a time constant of the falling portion of said pressure signal waveform being shorter than a time constant of the rising portion of said pressure signal waveform, causing the pressure to increase by a first speed during the rising portion and causing the pressure to decrease by a second speed faster than said first speed during the falling portion; and control means for controlling vehicle height in dependence upon the vehicle height signal and the smoothed pressure signal.
Claim 4
Dependent Claim
149 words
A vehicle height control apparatus receiving a vehicle height signal, comprising: height adjustment means for adjusting vehicle height using a pressurized fluid; pressure sensing means for sensing the pressure of the pressurized fluid and producing a pressure signal having rising and falling portions each having a slope; waveform shaping means for smoothing the pressure signal by decreasing the slope of the rising portion more than the slope of the falling portion, a time constant of the falling portion of said pressure signal waveform being shorter than a time constant of the rising portion of said pressure signal waveform, causing the pressure to increase by a first speed during the rising portion and causing the pressure to decrease by a second speed faster than said first speed during the falling portion; and control means for controlling vehicle height in dependence upon the vehicle height signal and the smoothed pressure signal.
Claim 5
Dependent Claim
141 words
A vehicle height control apparatus receiving a vehicle height signal, comprising: height adjustment means for adjusting vehicle height using a pressurized fluid; pressure sensing means for sensing the pressure of the pressurized fluid and producing a pressure signal having rising and falling portions each having a slope; waveform shaping means for smoothing the pressure signal by decreasing the slope of the rising portion more than the slope of the falling portion, said waveform shaping means comprising: a passive low-pass filter operatively connected to said pressure sensing means; a active low-pass filter operatively connected to said passive low-pass filter; and a pair of diodes operatively connected between said pressure sensing means and said active low-pass filter; and control means, operatively connected to said active low-pass filter, for controlling vehicle height in dependence upon the vehicle height signal and the smoothed pressure signal.
Claim 6
Dependent Claim
141 words
A vehicle height control apparatus receiving a vehicle height signal, comprising: height adjustment means for adjusting vehicle height using a pressurized fluid; pressure sensing means for sensing the pressure of the pressurized fluid and producing a pressure signal having rising and falling portions each having a slope; waveform shaping means for smoothing the pressure signal by decreasing the slope of the rising portion more than the slope of the falling portion, said waveform shaping means comprising: a passive low-pass filter operatively connected to said pressure sensing means; a active low-pass filter operatively connected to said passive low-pass filter; and a pair of diodes operatively connected between said pressure sensing means and said active low-pass filter; and control means, operatively connected to said active low-pass filter, for controlling vehicle height in dependence upon the vehicle height signal and the smoothed pressure signal.
Claim 7
Dependent Claim
89 words
A vehicle height control apparatus, comprising: a height control device for controlling vehicle height with a pressurized fluid; a fluid pressure sensor connected to said height control device; a passive low-pass filter operatively connected to said fluid pressure sensor; an active low-pass filter connected to said passive low-pass filter; a pair of diodes operatively connected between said fluid pressure sensor and said active low-pass filter; an A/D converter connected to said active low-pass filter; and a height control circuit connected to said A/D converter and said height control device.
Claim 8
Dependent Claim
89 words
A vehicle height control apparatus, comprising: a height control device for controlling vehicle height with a pressurized fluid; a fluid pressure sensor connected to said height control device; a passive low-pass filter operatively connected to said fluid pressure sensor; an active low-pass filter connected to said passive low-pass filter; a pair of diodes operatively connected between said fluid pressure sensor and said active low-pass filter; an A/D converter connected to said active low-pass filter; and a height control circuit connected to said A/D converter and said height control device.
Claim 9
Dependent Claim
113 words
An apparatus as recited in claim 4, wherein said active low-pass filter comprises: an operational amplifier having inverted and non-inverted inputs and having an output connected to the inverted input and said A/D converter; a first capacitor connected to the inverted input; a second capacitor connected between the non-inverted input and ground; a first resistor connected to said passive low-pass filter and said first capacitor; and a second resistor connected to the non-inverted input, said first resistor and said first capacitor, and wherein said pair of diodes includes: a first diode operatively connected between said first capacitor and said sensor; and a second diode operatively connected between the non-inverted terminal and said sensor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-29 | 1991-09-28 | 1992-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-29 | 1995-09-28 | 1996-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-29 | 1999-09-28 | 2000-03-29 | $7700.00 | Window Closed / Lapsed |