Signal processing system for vehicular acceleration sensor

Claim 2

A signal processing device for accelerating or decelerating a motor vehicle in response to a signal corresponding to a measured extent of depression of an accelerator pedal, said device comprising: an accelerator pedal sensor coupled to the accelerator pedal and detecting the extent of depression of the accelerator pedal, said accelerator pedal sensor comprising a fixed resistance having a value R2 and a potentiometer including a sliding contact connected to a power supply outputting a voltage E, said fixed resistance being connected in series with said potentiometer sliding contact forming an output node, and an output signal being produced at the output node; and correction means, coupled to said accelerator pedal sensor, for correcting the output signal produced by said accelerator pedal sensor, the correction changing nonlinearly depending upon the extent of depression of said accelerator pedal to produce a corrected accelerator signal which varies linearly with respect to the actual accelerator pedal displacement, said correction means including: an analog-to-digital converter for converting said output signal to a digital voltage value SD; and means for producing a corrected acceleration signal ACCV as a function of said digital voltage value SD, the value R2 of the fixed resistance R2, the value of the voltage E, and a constant C according to the following formula; ACCV=C×R2×SD/(10×E-SD).

Claim 3

A signal processing device for accelerating or decelerating a motor vehicle in response to a signal corresponding to a measured extent of depression of an accelerator pedal, said device comprising: an accelerator pedal sensor coupled to the accelerator pedal and detecting the extent of depression of the accelerator pedal, said accelerator pedal sensor comprising a fixed resistance having a value R2 and a potentiometer including a sliding contact connected to a power supply outputting a voltage E, said fixed resistance being connected in series with said potentiometer sliding contact forming an output node, and an output signal being produced at the output node; correction means, coupled to said accelerator pedal sensor, for correcting the output signal produced by said accelerator pedal sensor, the correction changing nonlinearly depending upon the extent of depression of said accelerator pedal to produce a corrected acceleration signal which varies linearly with respect to the actual accelerator pedal displacement, said correction means including: an analog-to-digital converter for converting said output signal to a digital voltage value SD; and means for producing a corrected acceleration signal ACCV as a function of said digital voltage value SD, the value of the fixed resistance R2, the value of the voltage E, and a constant C according to the following formula; ACCV=C×R2×SD/(10×E-SD): and resistance correction means for correcting the resistance value of said fixed resistance and said potentiometer which varies, depending upon production characteristics, from an ideal value.

Claim 4

A signal processing device for accelerating or decelerating a motor vehicle in response to a signal corresponding to a measured extent of depression of an accelerator pedal, said device comprising: an accelerator pedal sensor coupled to the accelerator pedal and detecting the extent of depression of the accelerator pedal, said accelerator pedal sensor comprising a fixed resistance having a value R2 and a potentiometer including a sliding contact connected to a power supply outputting a voltage E, said fixed resistance being connected in series with said potentiometer sliding contact forming an output node, and an output signal being produced at the output node; correction means, coupled to said accelerator pedal sensor, for correcting the output signal produced by said accelerator pedal sensor, the correction changing nonlinearly depending upon the extent of depression of said accelerator pedal to produce a corrected acceleration signal which varies linearly with respect to the actual accelerator pedal displacement, said correction means including: an analog-to-digital converter for converting said output signal to a digital voltage value SD; and means for producing a corrected acceleration signal ACCV as a function of said digital voltage value SD, the value of the fixed resistance R2, the value of the voltage E, and a constant C according to the following formula; ACCV=C×R2×SD/(10×E-SD): and resistance correction means for correcting the resistance value of said fixed resistance and said potentiometer which varies, depending upon production characteristics, from an ideal value.

Claim 5

A signal processing device according to claim 2, further comprising: a first switch connected to said correction means and detecting a maximum stroke of said accelerator pedal; and a second switch connected to said correction means and detectiang the release of said accelerator pedal, said correction means correcting the inclination of said linearized acceleration signal variation in accordance with the detected release of said accelerator pedal.

Claim 6

A signal processing device for accelerating or decelerating a motor vehicle in response to a signal corresponding to a measured extent of depression of an accelerator pedal, said device comprising: an accelerator pedal sensor coupled to the accelerator pedal and detecting the extent of depression of the accelerator pedal, said accelerator pedal sensor comprising a fixed resistance having a value R2 and a potentiometer including a sliding contact connected to a power supply outputting a voltage E, said fixed resistance being connected in series with said potentiometer sliding contact forming an output node, and an output signal being produced at the output node; and an idle switch, having contacts, positioned above the accelerator pedal, said contacts being closed when the accelerator pedal is not depressed, indicating an idling condition; and correction means connected to said accelerator pedal sensor for forming a linearlized acceleration signal which varies linearly with respect to actual displacement of the accelerator pedal sensor, and for calibrating a change in resistance of said potentiometer to correct the acceleration signal, said correction means including; an analog to digital converter for converting the output signal of said accelerator pedal sensor into a digital voltage value SD; memory means for storing a polynominal ACCV=C[C]×R2×SD/(A×[A]E-SD) for performing a linearlizing correction based on the value R2 of said fixed resistance, and the voltage E of the power supply based on the digital voltage value SD; and a central processing unit calculating a calibration coefficient COF when said idle switch is turned on in accordance with the following equation (1) on the basis of the polynominal, and for calculating a calibrated acceleration signal ACCV' in accordance with the following equation (2) from the calibration coefficient COF and linearlized corrected acceleration signal ACCV of said analog to digital converter: COF=B/ACCV.sub.[0] (1) ACCV'=B-COF×ACCV (2)

Claim 7

A signal processing device for accelerating or decelerating a motor vehicle in response to a signal corresponding to a measured extent of depression of an accelerator pedal, said device comprising: an accelerator pedal sensor coupled to the accelerator pedal and detecting the extent of depression of the accelerator pedal, said accelerator pedal sensor comprising a fixed resistance having a value R2 and a potentiometer including a sliding contact connected to a power supply outputting a voltage E, said fixed resistance being connected in series with said potentiometer sliding contact forming an output node, and an output signal being produced at the output node; and an idle switch, having contacts, positioned above the accelerator pedal, said contacts being closed when the accelerator pedal is not depressed, indicating an idling condition; and correction means connected to said accelerator pedal sensor for forming a linearlized acceleration signal which varies linearly with respect to actual displacement of the accelerator pedal sensor, and for calibrating a change in resistance of said potentiometer to correct the acceleration signal, said correction means including; an analog to digital converter for converting the output signal of said accelerator pedal sensor into a digital voltage value SD; memory means for storing a polynominal ACCV=C[C]×R2×SD/(A×[A]E-SD) for performing a linearlizing correction based on the value R2 of said fixed resistance, and the voltage E of the power supply based on the digital voltage value SD; and a central processing unit calculating a calibration coefficient COF when said idle switch is turned on in accordance with the following equation (1) on the basis of the polynominal, and for calculating a calibrated acceleration signal ACCV' in accordance with the following equation (2) from the calibration coefficient COF and linearlized corrected acceleration signal ACCV of said analog to digital converter: COF=B/ACCV.sub.[0] (1) ACCV'=B-COF×ACCV (2)

Claim 8

A signal processing system as recited in claim 4, said central processing unit further comprising memory means for storing said acceleration signal, at an idling position where said accelerator is released, to determine a calibrated acceleration signal at a ratio of an actual acceleration signal obtained from said sensor to the stored value in said memory means.

Claim 9

A signal processing device according to claim 5, wherein a calibrated acceleration signal ACCV' has a 0 value at the idling position, increases on the basis of the following equation as said accelerator is actuated, and to take a maximum value at a maximum actuated position where said actuator is actuated to its full stroke; ACCV'=B-COF×ACCV, where B designates the maximum output of said central processing unit, COF designates a calibration coefficient and ACCV is determined by the following equation: ACCV=C×R2×SD/(A×E-SD), where C designates a constant, R2 designates a resistance of said second resistance, SD designates the output of said analog to digital converter, A designates the output units of said analog digital converter, and E designates the voltage of said power supply.