Digitally controlled nitrogen oxide (NOx) sensor

Patent metadata

Field	Value
Publication number	US-12399084-B2
Application number	US-202218061566-A
Country	US
Kind code	B2
Filing date	Dec 5, 2022
Priority date	Oct 19, 2022
Publication date	Aug 26, 2025
Grant date	Aug 26, 2025

Abstract

A nitrogen-oxide (NOx) sensor control system includes a NOx sensor analog front-end, a temperature sensor analog front-end, and a processing system. The NOx sensor analog front-end is adapted to receive analog NOx sensor signals from a NOx sensor and is configured to convert the analog NOx sensor signals to digital NOx sensor signals. The temperature sensor analog front-end is adapted to receive analog temperature sensor signals from a temperature sensor and is configured to convert the analog temperature sensor signals to digital temperature sensor signals. The processing system is coupled to receive the digital NOx sensor signals and the digital temperature sensor signals and is configured, in response thereto, to: supply the digital NOx sensor signals to an external system, and control a flow of current to a heater element in the NOx sensor.

First claim

What is claimed is:

1. A nitrogen-oxide (NOx) sensor control system, comprising:
a NOx sensor analog front-end adapted to receive analog NOx sensor signals from a NOx sensor and configured to convert the analog NOx sensor signals to digital NOx sensor signals;
a temperature sensor analog front-end adapted to receive analog temperature sensor signals from a temperature sensor and configured to convert the analog temperature sensor signals to digital temperature sensor signals; and
a processing system, the processing system comprising:
a microcontroller coupled to receive the digital NOx sensor signals and the digital temperature sensor signals and configured, in response thereto, to (i) supply the digital NOx sensor signals to an external system and (ii) supply a resistance command,
a heater power source operable to supply a flow of current to a heater element; and
a digital potentiometer coupled to the heater power source and further coupled to receive the resistance command from the microcontroller, the digital potentiometer configured to control the flow of current from the heater power source to the heater element based on the resistance command.

2. The sensor control system of claim 1 , wherein the NOx sensor analog front-end comprises a multi-channel, multiplexed, analog-to-digital converter.

3. The sensor control system of claim 1 , further comprising an RS-232 transceiver coupled to receive the digital NOx sensor signals from the processing system.

4. The sensor control system of claim 1 , further comprising a controller area network (CAN) transceiver coupled to receive the digital NOx sensor signals from the processing system.

5. A nitrogen-oxide (NOx) sensor system, comprising:
a NOx sensor assembly including a NOx sensor, a heater element, and a temperature sensor, the NOx sensor configured to sense NOx gases and supply analog NOx sensor signals indicative of the sensed NOx gases, the heater element coupled to at least selectively receive a flow of current, the temperature sensor configured to sense a temperature of the NOx sensor and supply analog temperature sensor signals indicative of the sensed temperature; and
a NOx sensor control system coupled to the NOx sensor, the NOx sensor control system comprising:
a NOx sensor analog front-end adapted to receive the analog NOx sensor signals from the NOx sensor and configured to convert the analog NOx sensor signals to digital NOx sensor signals;
a temperature sensor analog front-end adapted to receive the analog temperature sensor signals from the temperature sensor and configured to convert the analog temperature sensor signals to digital temperature sensor signals;
a processing system, the processing system comprising:
a microcontroller coupled to receive the digital NOx sensor signals and the digital temperature sensor signals and configured, in response thereto, to (i) supply the digital NOx sensor signals to an external system and (ii) supply a resistance command,
a heater power source operable to supply a flow of current to a heater element; and
a digital potentiometer coupled to the heater power source and further coupled to receive the resistance command from the microcontroller, the digital potentiometer configured to control the flow of current from the heater power source to the heater element based on the resistance command.

6. The sensor system of claim 5 , wherein the NOx sensor analog front-end comprises a multi-channel, multiplexed, analog-to-digital converter.

7. The sensor system of claim 5 , further comprising an RS-232 transceiver coupled to receive the digital NOx sensor signals from the processing system.

8. The sensor system of claim 5 , further comprising a controller area network (CAN) transceiver coupled to receive the digital NOx sensor signals from the processing system.

9. A vehicle comprising:
a vehicle body;
an internal combustion engine disposed within the vehicle body and configured, when operating, to generate and emit exhaust gases;
a NOx sensor assembly disposed within the vehicle and including a NOx sensor, a heater element, and a temperature sensor, the NOx sensor disposed to receive at least a portion of the exhaust gases from the engine and configured to sense NOx gases in the exhaust gases and supply analog NOx sensor signals indicative of the sensed NOx gases, the heater element coupled to at least selectively receive a flow of current, the temperature sensor configured to sense a temperature of the NOx sensor and supply analog temperature sensor signals indicative of the sensed temperature; and
a NOx sensor control system disposed within the vehicle body and coupled to the NOx sensor assembly, the NOx sensor control system comprising:
a NOx sensor analog front-end coupled to receive the analog NOx sensor signals from the NOx sensor and configured to convert the analog NOx sensor signals to digital NOx sensor signals;
a temperature sensor analog front-end coupled to receive the analog temperature sensor signals from the temperature sensor and configured to convert the analog temperature sensor signals to digital temperature sensor signals;
a processing system, the processing system comprising:
a microcontroller coupled to receive the digital NOx sensor signals and the digital temperature sensor signals and configured, in response thereto, to (i) supply the digital NOx sensor signals to an external system and (ii) supply a resistance command,
a heater power source operable to supply a flow of current to a heater element; and
a digital potentiometer coupled to the heater power source and further coupled to receive the resistance command from the microcontroller, the digital potentiometer configured to control the flow of current from the heater power source to the heater element based on the resistance command.

10. The sensor system of claim 9 , wherein the NOx sensor analog front-end comprises a multi-channel, multiplexed, analog-to-digital converter.

11. The sensor system of claim 9 , further comprising an RS-232 transceiver coupled to receive the digital NOx sensor signals from the processing system.

12. The sensor system of claim 9 , further comprising a controller area network (CAN) transceiver coupled to receive the digital NOx sensor signals from the processing system and supply the digital NOx signals to the engine control module.

Assignees

• Honeywell Int Inc

Inventors

• Prabhu Prashant
• Basavarajappa Raghunanda

Classifications

• H05B1/0236

  for vehicles · CPC title

• G05D23/2037

  details of the regulator · CPC title

• G05D23/1917

  using digital means · CPC title

• G01M15/102 Primary

  by monitoring exhaust gases · CPC title