SAW Sensor Engine Knock Detection via Strain Measurement
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Solution Overview
Problem
Conventional engine knock detection systems are costly and complex, with limited sensitivity due to sensor placement dependencies, leading to inefficiencies in detecting engine knocking conditions.
Innovation Solution
A surface acoustic wave (SAW) sensor, such as a double-SAW sensor, is used to measure strain and engine torque, providing a wireless detection system that identifies engine knock through resonant frequency changes, allowing for accurate detection and control of engine operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional sensors are used for engine knock detection, then accurate indication of engine knock is provided, but system cost and complexity increase
Solution Approach 1:
The patent combines multiple sensor functions into a single piezoelectric sensor that simultaneously measures engine knock, engine torque, and other vibration parameters. This consolidation eliminates the need for separate sensors for each measurement, thereby reducing system complexity and cost while maintaining detection accuracy through the sensor's ability to capture multiple parameters through signal processing
2Measurement precision
If multiple sensors are disposed at various locations, then accurate engine knock indication is achieved, but system design cost increases
Solution Approach 1:
The patent consolidates multiple sensing locations and functions into a single piezoelectric sensor mounted on the engine block, eliminating the need for multiple sensors at various locations. The sensor captures vibration signals from multiple sources, and signal processing algorithms extract knock and torque information, thereby reducing manufacturing complexity and system design cost
3Measurement precision
If sensors are placed at specific locations, then engine knock detection sensitivity is improved, but sensor placement dependency increases design complexity
Solution Approach 1:
The patent makes the single piezoelectric sensor universal by enabling it to perform multiple functions: detecting engine knock, measuring engine torque, and monitoring other vibration parameters. The sensor is mounted in a standard location on the engine block and uses signal processing to extract multiple parameters, eliminating placement dependency and reducing design complexity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The SAW sensor-based system reduces system design costs and enhances sensitivity to engine knocking, enabling effective detection and control of engine knock conditions, while adapting to engine wear and operating parameter changes.
Implementation Method 1
The sensor may include a Surface-Acoustic Wave (SAW) sensor, such as, for example, a double-SAW sensor that concurrently detects engine torque
Implementation Method 2
A SAW-type sensor may function as a resonator whose resonant frequency changes, as the sensor is strained
Data Source
AI summary
An engine knock detection system for a vehicle engine includes a controller receiving an input indicative of strain applied to an engine component and an output for providing a signal indicative of engine knock. A sensor may be associated with the engine that measures operating parameters of the engine (i.e., strain, for example) to allow the controller to detect and identify engine knock. The sensor may include a Surface-Acoustic Wave (SAW) sensor, such as, for example, a double-SAW sensor that concurrently detects engine torque.