Optical Tracking System Using Strobe Patterns and Kalman Filters

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Solution Overview

Problem

Existing tracking systems face challenges in accurately tracking unpredictable and erratic movements of objects, especially when lighting conditions are poor and objects are far away, and struggle to simultaneously track multiple objects in real-time due to complexity in object recognition and occlusion issues.

Innovation Solution

A system utilizing two cameras and a tracking unit with infrared light sources and inertial measurement units, which combines image tracking and inertial tracking to determine the position and angular orientation of objects using Kalman filters, and employs strobe patterns to distinguish tracking light sources from others, allowing for accurate six-degrees-of-freedom tracking even at distances and in complex environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If visual imaging systems are used to capture movement, then tracking capability is provided, but processing is resource intensive and tracking response rate slows down

Engineering Contradiction:
Improvetracking capabilityVSAvoidtracking response rate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent replaces complex visual image processing with a simpler optical tracking system using light sources and photodetectors. Instead of processing digital images to track movement, the system uses optical signals that can be detected and processed much more quickly, directly addressing the contradiction between reliable tracking and fast response rate.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system changes the tracking parameter from image-based position detection to optical signal-based detection. By using light sources with specific characteristics (color, intensity patterns) and photodetectors, the system achieves both reliable tracking and high response rate, as optical signals can be processed much faster than images.

Inventive Principle:
Principle #35Parameter changes

2Length of stationary object

If sensors are positioned further away from the object being tracked, then tracking range is extended, but tracking inaccuracy increases

Engineering Contradiction:
Improvetracking rangeVSAvoidtracking accuracy
Core Design Contradiction:
Length of stationary objectVSMeasurement precision

Solution Approach 1:

The patent applies local quality by using light sources with specific optical characteristics (particular colors, intensity patterns) that create distinct local signatures. This allows the system to maintain high tracking accuracy even at long distances, as each light source has a unique optical signature that can be reliably detected and identified regardless of distance.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system uses light sources with specific colors and intensity patterns that create distinguishable optical signatures. By encoding tracking information in optical characteristics rather than relying solely on position detection, the system maintains accuracy at extended ranges.

Inventive Principle:
Principle #32Color changes

3Productivity

If multiple objects are tracked simultaneously in real-time, then tracking productivity increases, but complexity in object recognition and occlusion issues increases

Engineering Contradiction:
Improvemulti-object tracking capabilityVSAvoidobject recognition complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the tracking task by assigning unique optical signatures to each light source. Instead of processing complex images to recognize and distinguish multiple objects, the system uses distinct optical identifiers that can be detected independently, greatly simplifying the recognition process while enabling simultaneous multi-object tracking.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system introduces optical signals as an intermediary between the objects and the detection system. These optical signals serve as a simplified communication channel that carries identifying information, allowing multiple objects to be distinguished without complex image processing and reducing occlusion-related complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

The system achieves high-response-rate, accurate tracking of multiple objects in real-time, even at long distances and under varying lighting conditions, by integrating image and inertial data with Kalman filters and strobe patterns, ensuring reliable object identification and positioning.

Implementation Method 1

A system utilizing two cameras and a tracking unit with infrared light sources

Methodology Applied
Scientific EffectInfrared radiation emission: Infrared Radiation

Implementation Method 2

combines image tracking and inertial tracking to determine the position and angular orientation of objects

Methodology Applied
Scientific EffectInertial measurement: Inertia

Implementation Method 3

which combines image tracking and inertial tracking to determine the position and angular orientation of objects using Kalman filters

Methodology Applied
Scientific EffectKalman filtering: Feedback

Implementation Method 4

employs strobe patterns to distinguish tracking light sources from others

Methodology Applied
Scientific EffectStrobe lighting: Stroboscopic Effect

Data Source

PatentUS9747697B2System and method for tracking
Publication Date: 2017.08.29 CAST GROUP OF
  • US9747697B2 patent drawing
  • US9747697B2 patent drawing
  • US9747697B2 patent drawing

AI summary

Systems and methods are provided for generating calibration information for a media projector. The method includes tracking at least position of a tracking apparatus that can be positioned on a surface. The media projector shines a test spot on the surface, and the test spot corresponds to a known pixel coordinate of the media projector. The system includes a computing device in communication with at least two cameras, wherein each of the cameras are able to capture images of one or more light sources attached to an object. The computing device determines the object's position by comparing images of the light sources and generates an output comprising the real-world position of the object. This real-world position is mapped to the known pixel coordinate of the media projector.