# US 10,481,033 B2 · Diagnosing cylinder pressure sensor gain and offset > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,481,033 B2 - Document ID: US10481033B2 - Status: Granted - Kind: B2 - Application number: 14/971,527 - Filed: 2015-12-16 - Published: 2017-06-22 - Granted: 2019-11-19 - Earliest claimed: 2015-12-16 - Assignees: Cummins Inc. - Applicants: Cummins, Inc. - Inventors: Alok A. Joshi; Richard A. Booth; Edmund P. Hodzen - Web page: https://patentgrep.com/patent/US10481033B2 ## CPC - G01L 27/007: {Malfunction diagnosis, i.e. diagnosing a sensor defect} - F02D 35/023: {by determining the cylinder pressure} - F02D 41/222: {relating to the failure of sensors or parameter detection devices} - G01L 23/24: {specially adapted} for measuring pressure in inlet or exhaust ducts of internal-combustion engines - G01M 15/08: by monitoring pressure in cylinders - F02D 41/042: {for stopping the engine} - F02D 41/2474: {Characteristics of sensors} - F02D 2041/281: {between sensors and control unit} - F02D 2200/703: Atmospheric pressure - Y02T 10/40: Engine management systems - G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G) - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An apparatus includes a sensor module, an offset diagnostic module, and a notification module. The sensor module is in operative communication with a cylinder pressure sensor and structured to acquire cylinder pressure data from the cylinder pressure sensor indicative of an actual in-cylinder pressure of a cylinder of an engine. The offset diagnostic module is structured to interpret the cylinder pressure data to determine an offset of the cylinder pressure sensor based on a reference in-cylinder pressure and the actual in-cylinder pressure. The notification module is structured to provide an offset error notification responsive to the offset being greater than a threshold offset. ## Claims ### Claim 1 An apparatus, comprising: a sensor module in operative communication with a cylinder pressure sensor and structured to acquire cylinder pressure data from the cylinder pressure sensor indicative of an actual in-cylinder pressure of a cylinder of an engine while the engine is keyed on and the crankshaft of the engine is not rotating; an offset diagnostic module structured to interpret the cylinder pressure data to determine an offset of the cylinder pressure sensor based on a reference in-cylinder pressure and the actual in-cylinder pressure, wherein the reference in-cylinder pressure is based on an ambient pressure measured at a location external to the engine and an air intake system, wherein the offset of the cylinder pressure sensor is determined while the engine is keyed on and a crankshaft of the engine is not rotating; a gain diagnostic module structured to determine a gain of the cylinder pressure sensor while the engine is keyed on, the crankshaft of the engine is rotating, and the engine is not firing; and a notification module structured to provide an offset error notification responsive to the offset of the cylinder pressure sensor being greater than a threshold offset. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the gain diagnostic module is structured to: determine the gain of the cylinder pressure sensor responsive to the offset of the cylinder pressure sensor being less than the threshold offset and based on at least one of the actual in-cylinder pressure, the reference in-cylinder pressure, the offset of the cylinder pressure sensor, and a reference pressure profile; and compare the gain of the cylinder pressure sensor to a target gain range. ### Claim 3 (depends on 2) The apparatus of claim 2, wherein the notification module is structured to provide a gain error notification responsive to the gain of the cylinder pressure sensor being outside of the target gain range. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the sensor module is structured to acquire engine operation data indicative of at least one of a crank angle, an engine speed, an engine torque, an intake manifold temperature, an intake manifold pressure, a charge mass per cylinder, an exhaust pressure, and an exhaust temperature. ### Claim 5 (depends on 4) The apparatus of claim 4, further comprising an engine module structured to determine at least one of the reference in-cylinder pressure and the reference pressure profile based on the engine operation data. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the sensor module is in operative communication with an ambient pressure sensor and structured to interpret ambient pressure data from the ambient pressure sensor indicative of the ambient pressure. ### Claim 7 A method, comprising: determining a reference in-cylinder pressure for a cylinder of an engine based on an ambient pressure measured at a location external to the engine and an air intake system; measuring an actual in-cylinder pressure of the cylinder of the engine with a cylinder pressure sensor while the engine is keyed on and a crankshaft of the engine is not rotating; determining an offset of the cylinder pressure sensor based on the reference in-cylinder pressure and the actual in-cylinder pressure; comparing the offset of the cylinder pressure sensor to a threshold offset; providing an offset error notification responsive to the offset of the cylinder pressure sensor being greater than the threshold offset; and determining a gain of the cylinder pressure sensor while the engine is keyed on, the crankshaft of the engine is rotating, and the engine is not firing. ### Claim 8 (depends on 7) The method of claim 7, wherein the gain of the cylinder pressure sensor is determined responsive to the offset of the cylinder pressure sensor being less than the threshold offset. ### Claim 9 (depends on 7) The method of claim 7, wherein the gain of the cylinder pressure sensor is based on at least one of the actual in-cylinder pressure, the reference in-cylinder pressure, the offset of the cylinder pressure sensor, and a reference pressure profile. ### Claim 10 (depends on 9) The method of claim 9, further comprising determining at least one of the reference in-cylinder pressure and the reference pressure profile based on at least one of an estimate and a measurement of engine operation data, wherein the engine operation data provides an indication of at least one of a crank angle, an engine speed, an engine torque, an intake manifold temperature, an intake manifold pressure, a charge mass per cylinder, an exhaust pressure, and an exhaust temperature. ### Claim 11 (depends on 7) The method of claim 7, further comprising: comparing the gain of the cylinder pressure sensor to a target gain range; and providing a gain error notification responsive to the gain of the cylinder pressure sensor being outside of the target gain range. ### Claim 12 (depends on 7) The method of claim 7, further comprising measuring the ambient pressure with an ambient pressure sensor. ### Claim 13 A system, comprising: a cylinder pressure sensor configured to be communicably coupled to a cylinder of an engine and structured to measure an actual in-cylinder pressure of the cylinder while the engine is keyed on and the crankshaft of the engine is not rotating; and a controller configured to be communicably coupled to the engine and the cylinder pressure sensor, the controller structured to: determine an offset of the cylinder pressure sensor based on a reference in-cylinder pressure and the actual in-cylinder pressure, wherein the reference in-cylinder pressure is based on an ambient pressure measured at a location external to the engine and an air intake system, and wherein the offset of the cylinder pressure sensor is determined while the engine is keyed on and a crankshaft of the engine is not rotating; compare the offset of the cylinder pressure sensor to a threshold offset; provide an offset error notification responsive to the offset of the cylinder pressure sensor being greater than the threshold offset; and determine a gain of the cylinder pressure sensor responsive to the offset of the cylinder pressure sensor being less than the threshold offset, wherein the gain is determined while the engine is keyed on, the crankshaft of the engine is rotating, and the engine is not firing. ### Claim 14 (depends on 13) The system of claim 13, wherein the gain of the cylinder pressure sensor is based on at least one of the actual in-cylinder pressure, the reference in-cylinder pressure, the offset of the cylinder pressure sensor, and a reference pressure profile. ### Claim 15 (depends on 14) The system of claim 14, wherein at least one of the reference in-cylinder pressure and the reference pressure profile is based on at least one of an estimate and a measurement of engine operation data, wherein the engine operation data includes at least one of a crank angle, an engine speed, an engine torque, an intake manifold temperature, an intake manifold pressure, a charge mass per cylinder, an exhaust pressure, and an exhaust temperature. ### Claim 16 (depends on 13) The system of claim 13, wherein the controller is structured to compare the gain of the cylinder pressure sensor to a target gain range, wherein the controller is structured to provide a gain error notification responsive to the gain of the cylinder pressure sensor being outside of the target gain range. ### Claim 17 (depends on 13) The system of claim 13, further comprising an ambient pressure sensor structured to measure the ambient pressure.