Crank Pulse Analysis for Alcohol Concentration Detection
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Solution Overview
Problem
Existing alcohol concentration detection systems for Flex-Fuel Vehicles (FFVs) require multiple sensors, making them costly and complex, particularly for less expensive vehicles like motorcycles, where a more economical and sensor-less solution is needed to estimate and detect alcohol concentration for effective engine control.
Innovation Solution
An alcohol concentration estimation and detection apparatus that calculates average engine speed and crank angular speed variations using a crank pulse rotor, eliminating the need for sensors like oxygen and air flow sensors by employing a fuel injection map and alcohol concentration estimation maps to determine alcohol concentration based on crank pulse output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple sensors (oxygen sensor, air flow sensor) are used to detect alcohol concentration for FFV engine control, then the measurement precision and reliability of alcohol concentration detection is improved, but the device complexity and cost increase significantly
Solution Approach 1:
The crank pulse rotor is made to serve multiple functions: its primary function of detecting engine position and speed is enhanced to also detect alcohol concentration by analyzing variations in rotational speed. This eliminates the need for separate oxygen sensors and air flow sensors, reducing system complexity while maintaining detection accuracy through multi-purpose use of existing hardware
Solution Approach 2:
The system uses its own crank pulse rotor and existing rotational speed detection capability to detect alcohol concentration, rather than requiring external sensors. By analyzing variations in the rotor's rotational speed caused by changes in engine output power corresponding to different alcohol concentrations, the system makes the existing components serve the additional function of alcohol detection
2Reliability
If multiple sensors are installed for alcohol concentration detection, then the reliability of engine control is improved, but the system weight and size increase
Solution Approach 1:
The crank pulse rotor performs both its traditional function of engine position/speed detection and the new function of alcohol concentration detection, eliminating the need for additional sensor components that would add weight. The existing rotor and pickup coil system is utilized to extract multiple parameters including alcohol concentration through analytical processing of rotational speed variations
3Measurement precision
If traditional sensor-based alcohol concentration detection is used, then the measurement precision is improved, but the ease of manufacture and system cost worsen
Solution Approach 1:
The system uses its existing crank pulse rotor and rotational speed detection infrastructure to detect alcohol concentration, eliminating the need to manufacture and install additional expensive sensors. The alcohol concentration is derived from analyzing variations in the rotor's rotational speed, making the existing components serve the additional detection function without requiring new hardware manufacturing
Solution Approach 2:
The invention extracts the alcohol concentration detection capability from the rotational speed signal already being generated by the crank pulse rotor. By analyzing variations in rotational speed that correspond to different alcohol concentrations, the system extracts additional information from existing sensor output without requiring separate detection hardware
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
Enables accurate alcohol concentration detection and engine control without additional sensors, reducing system weight and size while maintaining effective ignition and fuel injection system control, thus providing a cost-effective and efficient solution for FFV engine management.
Implementation Method 1
a pickup coil for detecting a passing state of reluctors (teeth) provided on the pulse rotor and can detect various states of the engine based on a pulse signal outputted from the pickup coil
Data Source
AI summary
In an alcohol concentration estimation apparatus for an engine, a first crank angular speed (ω1) within a first predetermined interval overlapping with the compression top dead center is calculated, and a first variation amount (Δω1) is calculated by subtracting ω1 from an average engine speed. A second crank angular speed (ω2) within a second predetermined interval overlapping with the combustion bottom dead center is calculated, and a second variation amount (Δω2) is calculated by subtracting ω1 from ω2. In a relationship between air fuel ratio A/F and an indicated mean effective pressure (IMEP)/charging efficiency (ηc) of the engine when the engine is operated with a predetermined fuel injection map indicating a relationship between A/F and IMEP/ηc for each desired alcohol concentration, IMEP/ηc is substituted by Δω2/Δω1 ratio to estimate an alcohol concentration in fuel. The alcohol concentration estimation apparatus eliminates requirement of sensors for detecting an intake air mass.