Engine Controller Block Heater Determination for Cooling Diagnosis
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Solution Overview
Problem
Conventional technologies fail to accurately determine the energization status of a block heater in an internal combustion engine during stoppage, leading to potential erroneous diagnosis of cooling system abnormalities due to variations in coolant temperature behavior.
Innovation Solution
A controller with a block heater determination device that assesses the existence of energization based on coolant temperature and engine rotation speed behavior immediately after engine start, using change amounts, speeds, directions, and integration values, and includes an erroneous diagnosis prevention device to correct abnormality diagnoses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If block heater energization is not monitored during engine stoppage, then the abnormality diagnosis device can perform diagnosis based on coolant temperature behavior, but the diagnosis accuracy deteriorates due to unaccounted variations in coolant temperature caused by block heater energization
Solution Approach 1:
The system uses feedback from coolant temperature sensor readings and engine rotation speed sensor data to infer the block heater energization status. By monitoring the behavior of coolant temperature immediately after engine start and comparing it against expected patterns, the system determines whether the block heater was energized during stoppage, thereby recovering the lost information and improving diagnosis accuracy.
Solution Approach 2:
The abnormality diagnosis device performs self-diagnosis by using its existing sensors (coolant temperature sensor, engine rotation speed sensor) to infer the block heater energization status without requiring additional monitoring hardware. The system leverages the natural behavioral patterns of the engine and coolant system to generate the missing information about block heater operation.
2Measurement precision
If block heater energization status is determined by adding dedicated monitoring hardware, then the accuracy of energization detection improves, but the device complexity increases
Solution Approach 1:
The existing coolant temperature sensor and engine rotation speed sensor, originally designed for other purposes, are utilized to infer block heater energization status. This multi-functional use of existing sensors eliminates the need for dedicated monitoring hardware while maintaining accurate detection of block heater operation status.
Solution Approach 2:
The system uses its existing sensing capabilities to monitor block heater energization status without requiring additional specialized hardware. The abnormality diagnosis device leverages data from sensors already present in the engine system, making the monitoring function self-sufficient and avoiding increased device complexity.
3Device complexity
If coolant temperature is used as the sole basis for block heater determination, then the determination method remains simple, but the reliability decreases due to factors other than block heater energization affecting coolant temperature
Solution Approach 1:
The system combines multiple parameters - coolant temperature behavior and engine rotation speed behavior - to determine block heater energization status. By merging these two independent indicators, the system achieves more reliable determination while maintaining relatively simple processing logic, as both parameters are already being monitored by existing sensors.
Solution Approach 2:
The system uses feedback from multiple sensor sources (coolant temperature sensor and engine rotation speed sensor) to cross-validate the block heater energization status. The combined feedback from these parameters provides more reliable determination compared to using coolant temperature alone, while the processing remains integrated and unified.
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
Accurately determines block heater energization status, preventing erroneous cooling system diagnoses and improving the reliability and accuracy of coolant temperature estimation and control.
Implementation Method 1
heat of the block heater is fully transferred to the coolant in the cylinder block of the engine near the block heater
Implementation Method 2
circulation of the coolant in a coolant circulation line is also suspended during the engine stoppage
Data Source
AI summary
A plug of a power cord of a block heater, which is mounted to a cylinder block of an engine, is connected to a household power receptacle to energize the block heater during an engine stoppage in cold climate. Thus, an engine coolant is kept warm to prevent freeze. Existence/nonexistence of the energization to the block heater during the engine stoppage is determined based on a behavior of coolant temperature or a behavior of engine rotation speed immediately after an engine start. If it is determined that the energization to the block heater exists, abnormality diagnosis of a cooling system is prohibited or a condition for the abnormality diagnosis is corrected and estimation coolant temperature is corrected.