Wheel-Based Dead Reckoning Navigation for Indoor Cart Tracking
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Solution Overview
Problem
Existing methods for tracking the position of wheeled objects in large areas are either expensive, require extensive infrastructure, or are prone to errors due to signal interference and environmental factors, such as GPS signal blockages or RF signal attenuation.
Innovation Solution
A navigation system using dead reckoning methods, where the position of a wheeled object is determined by measuring its heading and wheel rotation, with error correction and position reset procedures, and can communicate with external markers and RF transmitters to activate anti-theft systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If GPS or RF tag systems are used to determine position, then position tracking capability is provided, but cost and infrastructure complexity increase significantly
Solution Approach 1:
The patent replaces electronic/GPS-based position tracking systems with a mechanical dead reckoning system that uses wheel rotation sensors and heading sensors to calculate position. This substitution eliminates the need for complex infrastructure like GPS satellites or RF transmitters/receivers, while providing reliable position tracking through mechanical measurement of distance traveled and direction oriented.
Solution Approach 2:
The wheeled object tracks its own position autonomously using onboard sensors (wheel rotation sensor and heading sensor) without requiring external infrastructure. The object serves itself by continuously measuring its own motion parameters and calculating its position relative to a starting point, eliminating dependency on external GPS or RF systems.
2Measurement precision
If GPS or RF systems are used for position determination, then location data is obtained, but susceptibility to signal interference and blockage increases
Solution Approach 1:
The patent replaces signal-based position determination (GPS/RF) with a mechanical measurement system that directly measures wheel rotation and heading. This mechanical approach is immune to electromagnetic signal interference, blockage, or attenuation, providing reliable position data in environments where GPS or RF systems fail, such as indoors or in areas with signal blockage.
3Device complexity
If dead reckoning is used to determine position from heading and wheel rotation, then cost and infrastructure requirements are reduced, but accumulated navigational error increases over time
Solution Approach 1:
The patent implements periodic position reset procedures where the system compares its calculated position with known reference points (such as magnetic markers or predefined locations) and resets the dead reckoning calculation when discrepancies exceed a threshold. This feedback mechanism prevents error accumulation by periodically correcting the position estimate, maintaining measurement precision over extended periods while keeping the system simple and infrastructure-light.
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
Provides a reliable, cost-effective, and autonomous means to track the position of wheeled objects, reducing errors and enabling activation of anti-theft mechanisms when objects exit designated areas.
Implementation Method 1
the heading is determined with reference to the Earth's magnetic field by disposing magnetic sensors in or on the object
Data Source
AI summary
A navigation system uses a dead reckoning method to estimate an object's present position relative to one or more prior positions. In some embodiments, the dead reckoning method determines a change in position from the object's heading and speed during an elapsed time interval. In embodiments suitable for use with wheeled objects, the dead reckoning method determines the change in position by measuring the heading and the amount of wheel rotation. Some or all of the components of the navigation system may be disposed within a wheel, such as a wheel of a shopping cart.