Multi-Beam Laser Projection for Robust Indoor Navigation
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Solution Overview
Problem
Conventional indoor navigation techniques face challenges such as occlusion, sensitivity issues, reliance on surface texture, and accumulation of positioning errors, which hinder accurate tracking of objects in indoor spaces, particularly in applications like construction and aircraft assembly, and often require excessive computational resources, power, and weight.
Innovation Solution
A multi-beam laser projection system that uses a laser projector to emit beams in various directions, with fixed cameras estimating the position and orientation of the projector and attached objects in indoor spaces, minimizing occlusion and sensitivity concerns by spreading beams over a large solid angle, and performing computations separately from the tracked object.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If vision-based navigation systems are used to interpret visual surroundings, then navigation capability is provided, but computational requirements become too great to run in real time
Solution Approach 1:
The system segments the navigation function by separating the heavy computational tasks (coordinate transformations, pose estimation) from the lightweight data collection (laser spot detection). The laser projector emits multiple beams that create spots on surfaces, and the system processes only the positions of these spots rather than full image interpretation, dividing the computational workload into manageable parts that can run in real-time on embedded systems.
Solution Approach 2:
The system replaces complex vision-based interpretation with a simplified optical-mechanical approach. Instead of using cameras to capture and interpret full visual scenes (which requires heavy computational processing), the system uses laser projectors to emit structured light beams and detectors to measure spot positions, substituting mechanical/optical measurement for computational image analysis.
2Volume of moving object
If object-tracking cameras are located close to one another, then system compactness is improved, but sensitivity decreases due to small angle measurements
Solution Approach 1:
The system transitions from two-dimensional camera image analysis to three-dimensional spatial measurement using laser geometry. By emitting laser beams in multiple directions and measuring the positions of spots on surfaces in 3D space, the system achieves accurate angle measurements even when the projector is located close to other components, as the multi-dimensional laser spot positions provide sufficient geometric information for precise pose estimation.
3Duration of action of moving object
If incremental positioning methods are used to track object location, then continuous tracking is provided, but errors accumulate which degrade positioning accuracy
Solution Approach 1:
The system implements feedback by continuously measuring the positions of laser spots on fixed surfaces and using these measurements to calculate the current pose of the laser projector. This closed-loop approach provides absolute positioning references from the fixed environmental surfaces, preventing error accumulation that occurs in open-loop incremental methods. The system constantly corrects its position estimate based on the observed laser spot positions.
Solution Approach 2:
The system performs preliminary calibration by establishing the coordinate system of the indoor space and the positions of fixed surfaces before operation. This pre-established reference framework allows the system to compute absolute positions rather than incremental changes, eliminating error accumulation. The calibration phase sets up the geometric relationships that are used throughout operation to maintain positioning accuracy.
4Ease of operation
If a navigation system is designed for small robots, then portability is improved, but power consumption and weight increase become impractical
Solution Approach 1:
The system extracts only the essential components needed for navigation from a complete vision system. Instead of mounting heavy cameras, processors, and power systems on the mobile robot, the patent places the laser projector on the robot and keeps the heavy computational infrastructure (cameras, processors) stationary in the environment. This extraction allows the mobile unit to be lightweight while maintaining full navigation capability through the distributed system architecture.
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 robust indoor navigation with reduced computational and power requirements, avoiding errors in object tracking and ensuring real-time operation in complex indoor environments.
Implementation Method 1
A laser projector on the object emits beams in four or more different directions
Data Source
AI summary
An indoor navigation system is based on a multi-beam laser projector, a set of calibrated cameras, and a processor that uses knowledge of the projector design and data on laser spot locations observed by the cameras to solve the space resection problem to find the location and orientation of the projector.