# US 9,435,707 B2 · Intra-cylinder pressure sensor fault diagnostic device and intra-cylinder sensor sensitivity correction device provided with same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,435,707 B2 - Document ID: US9435707B2 - Status: Granted - Kind: B2 - Application number: 14/350,626 - Filed: 2011-11-11 - Published: 2014-09-18 - Granted: 2016-09-06 - Earliest claimed: 2011-11-11 - Assignees: Toyota Jidosha Kabushiki Kaisha - Applicants: Keisuke Sasaki; Shigeyuki Urano - Inventors: Keisuke Sasaki; Shigeyuki Urano - Web page: https://patentgrep.com/patent/US9435707B2 ## CPC - G01L 23/00: Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid - F02D 35/023: {by determining the cylinder pressure} - F02D 37/02: one of the functions being ignition - F02D 41/009: {using means for generating position or synchronisation signals} - F02D 41/222: {relating to the failure of sensors or parameter detection devices} - F02D 41/2474: {Characteristics of sensors} - F02D 2041/227: {Limping Home, i.e. taking specific engine control measures at abnormal conditions} - F02P 5/00: Advancing or retarding ignition; Control therefor - 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) - F02P: IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES ({anti-pollution means for internal-combustion engines F02B17/00}; specially adapted for rotary-piston or oscillating-piston engines F02B53/12; {ignition of gas turbine plants F02C7/26; ignition of jet propulsion plants F02K9/95; starting of combustion engines F02N9/00}; ignition of combustion apparatus in general, glowing plugs F23Q; measuring of physical variables in general G01; controlling in general G05; data processing in general G06; electrical components in general see Section H; {ignition coils H01F38/12}; sparking plugs H01T13/00) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An intra-cylinder pressure sensor fault diagnostic device that ensures an opportunity for fault diagnosis in a wide operation region, and can accurately detect an intra-cylinder pressure with a high S/N ratio. The fault diagnostic device for an intra-cylinder pressure sensor, which outputs a value corresponding to an intra-cylinder pressure of an internal combustion engine delays ignition timing so that firing timing comes after a compression top dead center to generate peaks of the intra-cylinder pressure before firing and after firing respectively. When the ignition timing is delayed, at least one of an output value of the intra-cylinder pressure sensor in the peak of the intra-cylinder pressure before firing (hereinafter, called a pre-firing output peak value) and a crank angle thereof is detected. A fault of the intra-cylinder pressure sensor is determined by using at least one of the pre-firing output peak value and the crank angle thereof. ## Claims ### Claim 1 A fault diagnostic device for intra-cylinder pressure sensor that outputs a value corresponding to an intra-cylinder pressure of an internal combustion engine, wherein the fault diagnostic device is configured to: delay ignition timing so that firing timing comes after a compression top dead center to generate a peak of the intra-cylinder pressure before firing and a peak of the intra-cylinder pressure after firing; detect at least one of an output value of the intra-cylinder pressure sensor in the peak of the intra-cylinder pressure before firing (hereinafter, called a pre-firing output peak value) and a crank angle thereof, after the ignition timing is delayed by the fault diagnostic device; and diagnose presence or absence of a fault of the intra-cylinder pressure sensor by using at least one of the pre-firing output peak value and the crank angle thereof. ### Claim 2 (depends on 1) The fault diagnostic device according to claim 1, wherein the detecting includes detecting at least the pre-firing output peak value, and the diagnosing includes determining that a fault is present in the intra-cylinder pressure sensor, when a difference between the pre-firing output peak value and a determination value is at a predetermined value or larger. ### Claim 3 (depends on 2) The fault diagnostic device according to claim 2, wherein the fault diagnostic device is further configured to: store a relation between a load factor and a maximum intra-cylinder pressure of a motoring waveform; and acquire the maximum intra-cylinder pressure of the motoring waveform corresponding to a present load factor from the relation to set the maximum intra-cylinder pressure as the determination value. ### Claim 4 (depends on 2) The fault diagnostic device according to claim 2, wherein the fault diagnostic device is further configured to: correct an intra-cylinder pressure so that the difference between the pre-firing output peak value and the determination value becomes small, when a fault is determined to be present in the intra-cylinder pressure sensor. ### Claim 5 (depends on 1) The fault diagnostic device according to claim 1, wherein the detecting includes detecting at least a crank angle at which the pre-firing output peak value is detected, and the diagnosing includes determining that a fault is present in the intra-cylinder pressure sensor, when a difference between the crank angle at which the pre-firing output peak value is detected and the compression top dead center is at a predetermined value or larger. ### Claim 6 (depends on 5) The fault diagnostic device according to claim 5, wherein the fault diagnostic device is further configured to: correct a phase of an intra-cylinder pressure waveform so that the difference between the crank angle at which the pre-firing output peak value is detected and the compression top dead center becomes small, when a fault is determined to be present in the intra-cylinder pressure sensor.