Virtual Ignition Detection via Sensor Fusion
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Solution Overview
Problem
Vehicle telematics systems often face installation errors due to incorrect connection of the ignition input interface, leading to unnecessary battery drainage, as installers may mistakenly connect it to the wrong wire, causing the system to believe the ignition is always on.
Innovation Solution
The system estimates the vehicle's ignition state without directly connecting to the ignition line by monitoring power supply voltage, noise levels, AC coupling, vehicle vibrations using an accelerometer, and rate of voltage transitions on the OBD or data bus, combining these with GPS data to simplify installation and reduce errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the ignition input interface is directly connected to the vehicle ignition line, then the system can accurately detect the ignition state, but the installation complexity increases and installation errors may occur
Solution Approach 1:
The patent uses an intermediary approach by monitoring the power supply voltage and current instead of directly connecting to the ignition line. The power supply acts as a mediator that reflects the ignition state through its electrical characteristics, eliminating the need for direct ignition line connection while maintaining detection accuracy
Solution Approach 2:
The power supply unit serves multiple functions: it provides power to the telematics system and simultaneously acts as a sensor to detect ignition state through voltage and current monitoring. This multi-functionality reduces the number of separate components needed and simplifies installation
2Reliability
If the ignition input interface is directly connected to the vehicle ignition line, then the ignition state can be detected, but installation errors may cause the system to believe ignition is always on, leading to battery drainage
Solution Approach 1:
The system continuously monitors power supply voltage and current characteristics and compares them against expected ignition-state patterns. This feedback mechanism allows the system to verify whether the detected ignition state is consistent with actual vehicle operation, preventing false readings that would cause unnecessary battery drainage
Solution Approach 2:
The monitoring approach dynamically adapts to different vehicle states by analyzing changes in power consumption patterns. The system looks for dynamic transitions in voltage and current that correspond to actual ignition events, rather than relying on static connections that may be incorrectly wired
3Measurement precision
If multiple monitoring methods are used to determine ignition state, then the accuracy of ignition detection improves, but the device complexity increases
Solution Approach 1:
The patent combines multiple monitoring functions (voltage monitoring, current monitoring, and ignition detection) into a single integrated power supply unit. By merging these functions, the system achieves high detection accuracy without proportionally increasing device complexity, as the same hardware components serve multiple purposes
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 eliminates the need for direct ignition line connection, simplifying installation and reducing the likelihood of performance issues by accurately determining the ignition state using multiple indicators, thereby preventing battery drainage and installation errors.
Implementation Method 1
vehicle vibration indicative of ignition status is detected using an accelerometer
Implementation Method 2
the speed data is derived using the Doppler Effect
Implementation Method 3
changes in the voltage on the power supply line
Implementation Method 4
the noise level on the power supply line
Data Source
AI summary
Systems and methods for determining vehicle ignition state using a device added to the vehicle after the manufacture of the vehicle without a direct connection to the vehicle ignition line are disclosed. In a number of embodiments, a system includes a processor, a motion detector configured to detect vehicle motion and to enable the processor to obtain motion data, a Global Positioning System (GPS) receiver configured to determine location and to enable the processor to obtain at least speed data, and a radio transceiver configured to communicate with the processor. Additionally, the processor is configured to estimate the ignition state of a vehicle using at least the motion data and the speed data.