Canister Purge Control Using Intake Pressure Sensor
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Solution Overview
Problem
Conventional active purge systems for vehicles require multiple sensors, increasing the cost and complexity of the system, particularly in vehicles with reduced engine negative pressure, such as hybrid and turbocharger vehicles.
Innovation Solution
A canister purge control method that removes the rear-end pressure sensor from the active purge system, using the intake pressure sensor to determine the target purge flow rate and control the active purge pump, thereby reducing the number of sensors and system components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple sensors are installed in the active purge system to accurately control purge operations, then the reliability of purge control is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The intake pressure sensor, originally designed for engine intake pressure measurement, is made multi-functional by also using it to determine the rear-end pressure of the active purge pump. This eliminates the need for a separate rear-end pressure sensor while maintaining accurate purge control capability.
Solution Approach 2:
The functions of the intake pressure sensor and rear-end pressure sensor are merged by using the intake pressure sensor's data in combination with purge control solenoid valve opening degree information to infer the rear-end pressure conditions of the active purge pump, thereby reducing the total number of sensors required.
2Measurement precision
If multiple sensors are installed in the active purge system to accurately control purge operations, then the measurement precision of purge parameters is improved, but the manufacturing cost increases
Solution Approach 1:
The intake pressure sensor performs dual functions: measuring intake pressure for engine control and determining rear-end pressure conditions for purge pump control. This reuses existing hardware to achieve precise measurement without additional sensor costs.
Solution Approach 2:
The purge control solenoid valve opening degree serves as an intermediary parameter that, when combined with intake pressure sensor data, allows indirect but precise determination of rear-end pressure conditions, avoiding the need for direct pressure sensing at the pump outlet.
3Adaptability or versatility
If an active purge pump is added to enable purge operations in vehicles with reduced engine negative pressure, then the adaptability of the purge system is improved, but the device complexity increases
Solution Approach 1:
The active purge pump is integrated into the existing purge line and controlled through the existing purge control solenoid valve and intake pressure sensor, allowing it to perform purge operations while sharing control infrastructure with the engine management system, thereby limiting the increase in overall system complexity.
4Device complexity
If the rear-end pressure sensor is removed from the active purge system, then the device complexity is reduced, but the difficulty of detecting and measuring purge parameters increases
Solution Approach 1:
The purge control solenoid valve opening degree acts as an intermediary variable that enables indirect measurement of rear-end pressure conditions. By combining this with intake pressure sensor data, the system can infer purge pump outlet pressure without a dedicated sensor.
Solution Approach 2:
The direct mechanical pressure sensing at the pump outlet is replaced with a combined approach using electrical/control parameters (solenoid valve opening degree) and existing pressure sensor data, substituting a simpler sensing arrangement for the removed sensor.
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
This approach allows for effective canister purge operations in vehicles with reduced engine negative pressure without increasing costs, by utilizing existing sensors and reducing the number of components, thus lowering the fabrication cost.
Implementation Method 1
starting, by the control unit, an active purge pump of an active purge system provided in the vehicle, the active purge pump being disposed on the purge line
Implementation Method 2
recognizing, by the control unit, a purge gas pressure value measured by a front-end pressure sensor disposed on the purge line
Implementation Method 3
The canister is constructed by filling a container with an absorbent material able to absorb the fuel evaporation gas that has been introduced from the fuel tank
Implementation Method 4
a purge control solenoid valve (hereinafter referral to as "PCSV") that controls the purge operation is provided
Data Source
AI summary
A canister purge control method for a vehicle can reduce the number of components of an active purge system provided in the vehicle. An active purge operation is performed using a pressure value measured by an intake pressure sensor, instead of a pressure value measured by a rear-end pressure sensor, after a purge control solenoid valve is fully opened.