GPS Mileage Error Correction Using Accelerometer Data
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Solution Overview
Problem
Existing methods for determining vehicle odometer values using aftermarket GPS devices are prone to errors due to signal lock acquisition time, signal loss from obstructions, and power-saving modes, leading to inaccurate mileage calculations.
Innovation Solution
The use of onboard accelerometers to detect vehicle movement and combine with historical geographic data to calculate missing mileage during GPS signal loss, employing methods such as straight line or geographic map-assisted calculations to correct errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If GPS device is used to track location and measure driving distances, then mileage can be calculated without proprietary vehicle protocols, but errors accumulate over time making results useless
Solution Approach 1:
The patent combines GPS tracking with accelerometer-based motion detection to create a hybrid system. The accelerometer detects vehicle motion independently of GPS signal availability, and this motion data is merged with GPS location data to calculate complete mileage. This merging resolves the contradiction by maintaining measurement precision through accelerometer compensation while preserving GPS versatility for universal vehicle compatibility.
Solution Approach 2:
The accelerometer serves as an intermediary device that bridges the gap during GPS signal loss. When GPS signals are unavailable (during tunnels, bridges, or signal acquisition periods), the accelerometer continuously detects motion and provides intermediate mileage measurements. This intermediary mechanism ensures continuous accurate tracking without requiring constant GPS lock, resolving the accuracy problem while maintaining GPS system versatility.
2Measurement precision
If GPS receiver is kept on continuously to track movement, then mileage accuracy improves, but power consumption increases causing device to turn off for power savings
Solution Approach 1:
The patent replaces the power-intensive GPS receiver with a low-power accelerometer for motion detection during periods when GPS signals are unavailable or the device is in sleep mode. The accelerometer consumes minimal energy while continuously detecting vehicle motion, substituting the mechanical/electronic GPS signal acquisition process with a simpler inertial sensing approach. This substitution maintains mileage tracking accuracy during power-saving periods without requiring continuous GPS operation.
Solution Approach 2:
The system implements periodic GPS signal acquisition rather than continuous operation. The GPS receiver operates intermittently, waking up at scheduled intervals or when triggered by accelerometer-detected motion events. Between GPS periods, the accelerometer maintains motion tracking. This periodic action reduces power consumption significantly while preserving measurement precision through the complementary accelerometer data during GPS off-periods.
3Loss of energy
If GPS device operates in sleep state to save power, then energy consumption decreases, but movement tracking is lost creating mileage calculation errors
Solution Approach 1:
The accelerometer acts as an intermediary that continues to track movement information during GPS sleep periods. When the GPS receiver is powered down or in sleep mode, the accelerometer independently detects vehicle motion and captures movement data that would otherwise be lost. This intermediary data collection prevents information loss during power-saving states while maintaining minimal energy consumption.
Solution Approach 2:
The system performs preliminary motion detection using the accelerometer before GPS signal acquisition or during GPS sleep periods. By having the accelerometer ready and detecting motion in advance or during GPS off-times, the system ensures no movement information is lost. This preliminary action by the low-power accelerometer prepares or captures data that the higher-power GPS system would otherwise miss during sleep states.
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 automates error correction, providing more accurate vehicle mileage calculations by accounting for movement during signal loss periods without requiring continuous GPS signal lock, thus improving the reliability of mileage tracking.
Implementation Method 1
Some embodiments utilize additional sensors to detect vehicle movement
Data Source
AI summary
A method for compensating for the absence of GPS data during a period of GPS signal loss in determining travel mileage of a vehicle includes: detecting vehicle motion using an accelerometer during a period of time in which a GPS tracking device is unable to determine a location of the vehicle due to loss of GPS signal; determining a first location of the vehicle corresponding to the last known GPS location data point stored in memory; determining a second location of the vehicle corresponding to a point at which the GPS signal is reacquired; and calculating the distance between the first and second locations based on a straight-line distance calculation between the first and second locations, or based on the use of geospatial mapping data to plot a roadway route between the first and second locations.