Actuator Diagnostic Apparatus for Low Battery Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing actuator diagnostic systems for vehicle electronic control units face challenges in accurately diagnosing shutdown operations during the cranking step when battery voltage is insufficient, due to delays and current leakage issues, which hinder precise diagnosis.
Innovation Solution
An actuator diagnostic apparatus comprising a high-side driver, low-side driver, pull-down switch, shutdown driver, and diagnostic control unit, which sequentially actuates these components to diagnose actuator shutdown by sensing output voltage changes and removing leakage current through a pull-down resistor, enabling accurate diagnosis even at low battery voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If shutdown diagnosis is performed during cranking step when battery voltage is insufficient, then actuator shutdown can be diagnosed in emergency situations, but diagnosis accuracy deteriorates due to voltage insufficiency and current leakage
Solution Approach 1:
A pull-down resistor is introduced as an intermediary component to actively remove leakage current from the actuator during shutdown diagnosis. The resistor provides a controlled path to ground that eliminates the harmful leakage current that would otherwise interfere with voltage-based diagnosis, enabling accurate shutdown detection even when battery voltage is insufficient during cranking operation.
Solution Approach 2:
The system changes the electrical parameters (voltage and current) by actively controlling the actuator through high-side and low-side drivers, and by using the pull-down resistor to modify the current flow characteristics. This parameter control allows the system to create measurable voltage changes that can be detected even in low-voltage cranking conditions.
2Adaptability or versatility
If threshold value for shutdown diagnosis is lowered to enable diagnosis at low battery voltage, then diagnosis becomes possible during cranking, but current leakage from biasing prevents accurate detection
Solution Approach 1:
The pull-down resistor converts the harmful leakage current into a beneficial diagnostic signal. By providing a controlled leakage path, the resistor creates a predictable voltage drop that can be measured and used to determine actuator shutdown status. The previously harmful current leakage becomes a useful indicator for diagnosis.
Solution Approach 2:
The pull-down resistor acts as an intermediary that mediates between the actuator and the diagnostic system. It provides a known, controlled path for current flow that allows the diagnostic control unit to accurately interpret voltage measurements and determine shutdown status, even when the actuator itself is not conducting current.
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 solution improves the diagnostic range by lowering the threshold value for shutdown diagnosis, ensuring accurate actuator shutdown detection during vehicular emergencies, even when battery voltage is insufficient, thus enhancing readiness for emergency situations.
Implementation Method 1
an output voltage sensing unit which senses an output voltage of the high-side driver
Implementation Method 2
a pull-down switch which pulls down an input voltage of the high-side driver
Data Source
AI summary
An actuator diagnostic apparatus is provided for an electronic control unit of a vehicle. The actuator diagnostic apparatus of the electronic control unit for a vehicle is characterized by containing: a high-side driver which drives an actuator from a high-side; an output voltage sensing unit which senses an output voltage of the high-side driver; a low-side driver which drives the actuator from a low-side; a pull-down switch which pulls down an input voltage of the high-side driver; a shutdown driver which actuates the pull-down switch; and a diagnostic control unit which diagnoses shutdown of the actuator upon receiving an input of the output voltage from the output voltage sensing unit after respectively actuating the high-side driver, the low-side driver, and the shutdown driver in accordance with a shutdown diagnosis order.