Mobile Navigation Device Power Management via GPS Dead Reckoning Switching
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Solution Overview
Problem
Mobile navigation devices face a technical bottleneck in reducing power consumption for GPS receivers, as they must remain continuously enabled for navigation, leading to increased energy usage.
Innovation Solution
A mobile navigation device operates in alternating modes, using a satellite positioning module for initial position calculation and a dead reckoning module for subsequent updates, switching between modes based on conditions to conserve power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the GPS receiver is continuously enabled for navigation, then navigation accuracy is maintained, but power consumption increases
Solution Approach 1:
The system alternates between GPS mode and dead reckoning mode in periodic cycles. The GPS receiver is activated only during GPS mode to acquire position information, then deactivated during dead reckoning mode to save power. This periodic switching resolves the contradiction by maintaining navigation capability through alternating use of high-accuracy (but high-power) GPS and low-power dead reckoning estimation.
Solution Approach 2:
The dead reckoning module serves as an intermediary between GPS measurements. When GPS is unavailable or in power-saving mode, dead reckoning using acceleration sensors and gyroscopes provides continuous position estimation. This intermediary maintains navigation functionality without requiring continuous GPS operation, thus reducing power consumption while preserving navigation accuracy.
2Duration of action of moving object
If the GPS receiver is continuously enabled, then position tracking is continuous, but battery life decreases
Solution Approach 1:
The navigation system operates in periodic cycles alternating between GPS mode (for accurate position updates) and dead reckoning mode (for continuous position estimation with lower power consumption). This periodic operation ensures continuous position tracking capability while significantly extending battery life by avoiding continuous GPS reception.
Solution Approach 2:
The system performs preliminary action by acquiring GPS position information when available, then uses this previously obtained data combined with dead reckoning for subsequent position estimates. This preliminary GPS data serves as a baseline that reduces the need for continuous GPS operation, thereby extending battery life while maintaining tracking continuity.
3Use of energy by moving object
If dead reckoning is used instead of GPS, then power consumption is reduced, but navigation accuracy deteriorates
Solution Approach 1:
The system periodically switches between dead reckoning mode (low power, lower accuracy) and GPS mode (high power, high accuracy). During dead reckoning intervals, power consumption is reduced. When GPS signals are available, the system transitions to GPS mode to refresh position accuracy, thus resolving the contradiction by alternating between the two modes based on signal availability and power management requirements.
Solution Approach 2:
The navigation system merges dead reckoning estimation with periodic GPS corrections. The dead reckoning module continuously estimates position based on sensor data, while GPS provides periodic correction updates. This combination allows the system to operate at low power using dead reckoning while maintaining navigation accuracy through intermittent GPS corrections, thus resolving the accuracy-power contradiction.
Data Source
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AI summary
A mobile navigation device operating in a first mode and a second mode is provided. In the first mode, a satellite positioning module is activated while a dead reckoning module is disabled. A processor calculates the coordinates of the mobile navigation device based on the satellite navigation signals received by the satellite positioning module. In the second mode, the satellite positioning module is disabled while the dead reckoning module is activated, and the processor updates the coordinates based on displacements and rotations detected by the dead reckoning module.