Spatially-Distributed Transmitter System for Reflective Object Tracking
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Solution Overview
Problem
Current techniques for determining the position and motion of a non-cooperative, reflective object suffer from measurement errors in inertial guidance systems and require signal transmission in radar systems, limiting their accuracy and applicability.
Innovation Solution
A spatially-distributed transmitter system with coded signals allows a receiver to determine its own position, orientation, and the position and motion of a reflective object by measuring differential and absolute time-of-arrival of signals from multiple transmitters, eliminating the need for signal transmission and reducing measurement errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If radar systems are used to determine the position and motion of a non-cooperative object, then the object's position can be tracked, but signal transmission is required which limits accuracy and applicability
Solution Approach 1:
The patent uses a spatially-distributed transmitter system as an intermediary between the receiver and the non-cooperative object. The transmitters provide reference signals that enable the receiver to determine both its own position and the object's position without the receiver needing to transmit signals. This mediator system resolves the contradiction by providing the necessary reference framework while eliminating the need for receiver signal transmission.
Solution Approach 2:
The spatially-distributed transmitter system serves multiple functions simultaneously: it enables the receiver to determine its own position and orientation, tracks the non-cooperative object, and provides reference signals for both purposes. This multi-functionality resolves the contradiction by consolidating what would otherwise require separate systems into a single unified approach.
2Measurement precision
If inertial guidance systems are used to determine self-position and self-motion, then position information can be obtained, but measurement errors accumulate progressively
Solution Approach 1:
The patent implements feedback by using the spatially-distributed transmitter system to continuously provide reference signals that allow the receiver to determine its position absolutely rather than relatively. This feedback mechanism corrects the accumulated errors of inertial guidance systems by periodically resetting the position reference against known transmitter locations, thereby maintaining long-term accuracy.
Solution Approach 2:
The system performs preliminary action by establishing a network of spatially-distributed transmitters with known positions before the tracking operation begins. These pre-positioned transmitters create a reference framework that the receiver can use to continuously correct its position estimates, preventing error accumulation before it becomes significant.
3Productivity
If a monostatic radar system is located onboard the vehicle to track non-cooperative objects, then position tracking is achieved, but radar search and track resources limit the number of vehicles and objects that can be tracked
Solution Approach 1:
The patent segments the radar function by separating the transmitter system from the receiver. Multiple receivers can operate simultaneously using a shared spatially-distributed transmitter system, allowing multiple vehicles to track multiple objects concurrently. This segmentation resolves the contradiction by enabling resource sharing that increases overall system productivity without proportionally increasing power requirements.
Solution Approach 2:
The spatially-distributed transmitter system provides self-service by generating the reference signals that all receivers need for tracking. Each receiver independently processes these signals to determine positions without requiring dedicated radar transmissions from each vehicle. This self-service approach allows unlimited scalability in the number of vehicles and objects that can be tracked simultaneously.
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 method enables precise tracking of a reflective object while accurately determining the receiver's position and orientation, improving tracking accuracy and range without the need for signal transmission, and allowing simultaneous self-positioning and object tracking.
Implementation Method 1
The radar system would transmit and receive radio waves reflected off the non-cooperative object
Implementation Method 2
measuring differential and absolute time-of-arrival of signals from multiple transmitters
Data Source
AI summary
Measurements of the differential and/or absolute time-of-arrival of separable signals transmitted from a set of spatially-distributed (SD) transmitters are obtained by one or more receivers. The signals transmitted by each transmitter are made separable by encoding them in a manner that enables each signal to be distinguished from the others by the receiver or receivers. An accurate time-of-arrival of each signal at the receiver is determined, from which the path lengths from the transmitters to the receiver and from the receiver to the object are determined based on the known propagation speed of the signals. Any Doppler frequency shifts in each signal can also be determined from this information. From all of this information, the receiver is able to determine its own position, motion and orientation (roll, pitch and yaw), as well as the position and motion of the moving object being tracked by the receiver.