Radio Wave Phase Comparison for Position and Orientation Measurement
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Solution Overview
Problem
Existing methods for determining the distance and orientation of a movable object in navigation and metrology suffer from increasing errors due to unknown sensor biases and require complex synchronization and calibration processes.
Innovation Solution
An apparatus and method using a transmitter with a linearly polarized antenna and a receiver with circularly polarized antennas, allowing for phase comparison of received signals to calculate distance and orientation without modulation, and employing synchronization and TDOA methods to correct for timing errors, enabling simple and precise evaluation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If inertial sensor systems are used to determine orientation and movement, then the measurement can be performed with magnetic field sensors, gyroscopes or acceleration sensors, but unknown bias or offset of the sensors results in errors that increase over time
Solution Approach 1:
The patent introduces radio wave signals as an intermediary measurement medium that does not suffer from sensor bias. By using phase comparison of transmitted and received radio signals, the system obtains absolute position and orientation references that correct the accumulating errors from inertial sensors, eliminating the need for frequent support measurements.
Solution Approach 2:
The patent replaces mechanical inertial sensors with an electromagnetic field-based measurement system. Instead of using physical gyroscopes, accelerometers, or magnetic field sensors that accumulate bias errors, the system uses radio wave phase comparison to directly determine position and orientation, substituting a mechanical sensing approach with an electromagnetic wave-based approach.
2Measurement precision
If camera-based systems are used to determine orientation and position, then at least three markings are applied to the measured object which are detected by cameras, but the system becomes more complex
Solution Approach 1:
The patent extracts the essential measurement function from complex camera-based systems. Instead of using multiple cameras to detect three-dimensional positions of multiple markings, the system uses a single transmitter-receiver pair with phase comparison to directly obtain position and orientation, extracting only the necessary measurement capability while removing unnecessary complexity.
Solution Approach 2:
The patent changes the measurement parameter from visual detection of multiple markings to phase comparison of radio signals. By using phase as the primary measurement parameter instead of spatial coordinates of multiple markers, the system achieves equivalent measurement precision with fewer physical components and simpler processing.
3Measurement precision
If GPS system is used to determine alignment of a ship, then radio signals from satellites are received with a rotating antenna or arrangement of antennas, but the system requires complex phase comparison between rotation period and phase measurement
Solution Approach 1:
The patent segments the measurement function into separate transmitter and receiver units, each with fixed antennas. Instead of using a rotating antenna system that must perform complex phase comparisons over rotation periods, the system divides the measurement task into independent transmitter and receiver segments that can operate simultaneously with simpler fixed antenna configurations.
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 provides accurate and resilient distance and orientation calculations, reducing errors and simplifying the evaluation process, allowing for both relative and absolute positioning without the need for complex initial synchronization.
Implementation Method 1
a transmitter (8) which is arranged changeably in its position with respect to a fixed receiver (2), the transmitter (8) being connected to an antenna (3) via which a transmitted signal generated in the transmitter (1) is emitted
Implementation Method 2
the receiver (2) or an evaluation unit determines the phasing of the carrier frequency of the two received signals with respect to the phasing of the defined frequency (f0) of the transmitter (1)
Implementation Method 3
at least one transmitter and at least one receiver are used, in the apparatus and in the method, with a respective one of both having an antenna with a known polarization plane and the other of both (transmitter and receiver) having a left-hand circularly polarized antenna and a right-hand circularly polarized antenna
Data Source
AI summary
A device and method for determining a distance and/or orientation of a movable object includes a transmitter that is located on the object and a receiver. One of the transmitter and the receiver has an antenna having a known polarization plane. The other of the transmitter and the receiver has a counterclockwise circular polarized antenna and a clockwise circular polarized antenna.