Pressure detection signal processing device, engine control system, and non-transitory computer readable medium storing a program

Patent metadata

Field	Value
Publication number	US-10895513-B2
Application number	US-201916687629-A
Country	US
Kind code	B2
Filing date	Nov 18, 2019
Priority date	Nov 19, 2018
Publication date	Jan 19, 2021
Grant date	Jan 19, 2021

Abstract

A pressure detection signal processing device, engine control system, and non-transitory computer readable medium storing a program are provided. A current-voltage conversion part that converts a current signal corresponding to charge generated by a piezoelectric element in accordance with received pressure into a voltage signal, and digital signal processing parts that perform correction for removing a drift caused by a leakage current of the piezoelectric element on the voltage signal through digital signal processing are provided. The digital signal processing parts include a differentiation processing part that performs differentiation processing on the voltage signal, an integration processing part that performs integration processing on the signal having been subjected to the differentiation processing, and an integration processing part that further performs integration processing on the signal having been subjected to the integration processing.

First claim

What is claimed is:

1. A pressure detection signal processing device that performs signal processing on an output signal of a pressure sensor comprising a piezoelectric element generating charge according to received pressure, the pressure detection signal processing device comprising:
a current-voltage conversion part which converts a current signal corresponding to the charge into a voltage signal; and
a digital signal processing part which performs correction for removing a drift of the piezoelectric element on the voltage signal through digital signal processing,
wherein the digital signal processing part comprises
a differentiation processing part which performs differentiation processing on the voltage signal,
a first integration processing part which performs integration processing on the signal having been subjected to the differentiation processing, and
a second integration processing part which performs integration processing on the signal having been subjected to the integration processing.

2. The pressure detection signal processing device according to claim 1 ,
wherein the current-voltage conversion part comprises an operation amplifier which is connected in a negative feedback manner using a resistor.

3. An engine control system, comprising:
the pressure detection signal processing device according to claim 1 ; and
a control part which controls an engine on the basis of an output signal from the pressure detection signal processing device.

4. A pressure detection signal processing device that performs signal processing on an output signal of a pressure sensor comprising a piezoelectric element generating charge according to received pressure, the pressure detection signal processing device comprising:
a current-voltage conversion part which converts a current signal corresponding to the charge into a voltage signal;
an extraction part which extracts a component in a specific frequency band of the voltage signal; and
a digital signal processing part which performs correction processing for removing a drift of the piezoelectric element through digital signal processing on the basis of the voltage signal and an extracted signal which has been extracted,
wherein the digital signal processing part comprises
a subtraction processing part which obtains a subtraction signal indicating a result of a subtraction calculation with respect to the voltage signal and the extracted signal, and
an integration processing part which performs integration processing on the subtraction signal.

5. The pressure detection signal processing device according to claim 4 ,
wherein the extraction part is a low-pass filter that extracts a component in a predetermined low frequency band.

6. The pressure detection signal processing device according to claim 5 ,
wherein the low-pass filter is configured such that a resistor and a capacitor are connected to each other in series and is configured to output a voltage from both ends of the capacitor as the extracted signal.

7. The device according to claim 5 ,
wherein the digital signal processing part changes a cutoff frequency of the low-pass filter in accordance with a rotational speed of an engine.

8. A non-transitory computer readable medium storing a program for causing a computer to execute following functions:
for causing a pressure detection signal device that performs signal processing on an output signal of a pressure sensor comprising a piezoelectric element generating charge according to received pressure to realize:
a signal processing function of performing correction processing for removing a drift of the piezoelectric element on a voltage signal converted from a current signal corresponding to the charge by a current-voltage conversion part,
wherein the signal processing function comprises
a differentiation processing function of performing differentiation processing on the voltage signal,
a first integration function of performing integration processing on the signal having been subjected to the differentiation processing, and
a second integration function of performing integration processing on the signal having been subjected to the integration processing.

9. A non-transitory computer readable medium storing a program for causing a computer to execute following functions:
for causing a pressure detection signal device that performs signal processing on an output signal of a pressure sensor comprising a piezoelectric element generating charge according to received pressure to realize:
a signal processing function of performing correction processing for removing a drift of the piezoelectric element on the basis of a voltage signal converted from a current signal corresponding to the charge by a current-voltage conversion part and an extracted signal obtained by extracting a specific frequency component of the voltage signal,
wherein the signal processing function comprises
a subtraction processing function of obtaining a subtraction signal indicating a result of a subtraction calculation with respect to the voltage signal and the extracted signal, and
an integration function of performing integration processing on the subtraction signal.

Assignees

• Mikuni Kogyo Kk

Inventors

• Takahashi Ren
• Fukui Katsuhiko

Classifications

• F02D2200/101

  Engine speed · CPC title

• F02D35/023 Primary

  by determining the cylinder pressure · CPC title

• G01L23/222 Primary

  using piezoelectric devices · CPC title

• F02D41/0097

  using means for generating speed signals · CPC title

• F02D41/1444

  characterised by the characteristics of the combustion gases · CPC title