# US 2021/0278317 A1 · Engine apparatus and noise detection system

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- Number: US 2021/0278317 A1
- Document ID: US20210278317A1
- Status: Published application
- Kind: A1
- Application number: 17/158,010
- Filed: 2021-01-26
- Published: 2021-09-09
- Earliest claimed: 2020-03-03
- Assignees: Toyota Jidosha Kabushiki Kaisha
- Applicants: Toyota Jidosha Kabushiki Kaisha
- Inventors: Yoshiya YAMASHITA
- Web page: https://patentgrep.com/patent/US20210278317A1

## CPC

- G01M 15/06: by monitoring positions of pistons or cranks
- F02D 41/009: {using means for generating position or synchronisation signals}
- G01L 23/225: {circuit arrangements therefor}
- G01M 15/042: {by monitoring a single specific parameter not covered by groups G01M15/06 - G01M15/12}
- F02D 2200/025: Engine noise, e.g. determined by using an acoustic sensor
- F02D 2200/101: Engine speed
- Y02T 10/40: Engine management systems
- G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- 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)
- G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A specific sound having a higher frequency than an operation sound of an engine is generated in synchronization with timing of a top dead center of a specific cylinder of the engine. Thus, timing of a noise of the engine is estimated by using, for example, a deviation in time between timing of generation of a specific sound and timing at which a noise occurs in the engine, based on a sound collected from around the engine without directly using a signal of a crank angle of the engine.

## Claims

### Claim 1

An engine apparatus comprising:
an engine; and
a specific sound generator configured to generate a specific sound having a higher frequency than an operation sound of the engine in synchronization with timing of a top dead center of a specific cylinder of the engine.

### Claim 2 (depends on 1)

The engine apparatus according to claim 1, wherein the specific sound is a sound having a higher frequency than an audible frequency range.

### Claim 3 (depends on 1)

The engine apparatus according to claim 1, further comprising a crank angle sensor configured to detect a crank angle of the engine, wherein:
the specific sound generator is configured to estimate the timing of the top dead center of the specific cylinder based on the detected crank angle; and
the specific sound generator is configured to generate the specific sound in synchronization with the timing of the top dead center of the specific cylinder.

### Claim 4 (depends on 1)

A noise detection system comprising:
the engine apparatus according to claim 1, wherein:
the engine is accommodated in an engine compartment of a vehicle;
the specific sound generator is disposed in the engine compartment or attached to a wall part of the engine compartment; and
the noise detection system further comprises:
a sound collector configured to collect a sound in the engine compartment; and
an estimator configured to estimate presence or absence and timing of generation of a noise based on the sound collected by the sound collector.