Construction Site Localization Using Coarse-to-Fine Positioning

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Solution Overview

Problem

Existing methods for locating target positions on construction sites, especially indoors or in areas with unreliable satellite signals, are unreliable due to the need for line-of-sight and the inability to differentiate between symmetrically structured areas.

Innovation Solution

A multi-step localization method using a device that performs coarse localization by evaluating identification markings, natural signals, or external signals to determine the part of the construction site where the target position is located, and then uses fine localization techniques like total stations or LIDARs to accurately pinpoint the target.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If satellite-based tracking systems are used for localization, then global positioning capability is improved, but reliability deteriorates in areas with insufficient signal strength such as indoor construction sites

Engineering Contradiction:
Improvepositioning reliabilityVSAvoidsignal availability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent introduces intermediate reference points (calibration markings) placed throughout the construction site as mediators between the total station and the target position. These reference points enable indirect positioning by providing measurable references that bridge the line-of-sight gaps, allowing reliable localization without direct satellite signals in indoor environments

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The construction site is segmented into multiple zones with distributed calibration markings and reference points. Instead of relying on a single global satellite signal, the system divides the positioning task into local measurements between the total station, intermediate reference points, and target positions, enabling reliable localization in signal-denied environments

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If total station is used for fine localization, then measurement precision is improved, but reliability deteriorates due to inability to differentiate between symmetrically structured areas

Engineering Contradiction:
Improvepositioning precisionVSAvoidlocation accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent employs asymmetric identification markings with unique patterns, numbers, or configurations at each calibration point and reference location. These asymmetric features enable the total station to distinguish between symmetrically structured areas (e.g., identical rooms or floors), preventing misidentification and ensuring reliable target position localization even in repetitive building layouts

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

Calibration markings and reference points with unique identification features are pre-established throughout the construction site before construction begins. This preliminary setup creates a known geometric framework that the total station can use for accurate positioning, eliminating the need to establish references during construction and ensuring consistent differentiation between symmetric areas

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If total station requires line of sight for positioning, then measurement precision is improved, but ease of operation deteriorates due to requirement of being located in correct part of construction site

Engineering Contradiction:
Improvecoordinate determination accuracyVSAvoidsetup complexity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent extends the positioning system into multiple dimensions by distributing calibration markings and reference points throughout three-dimensional space (across multiple floors, walls, and ceilings). This spatial distribution creates multiple potential line-of-sight paths from the total station to reference points, allowing operators to maintain precise measurements from various locations without requiring exact positioning in predetermined spots

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP4567377A1Method for locating a target position, locating device, computer program product and construction robot
Publication Date: 2025.06.11 HILTI AG
  • EP4567377A1 patent drawingFigure 1
  • EP4567377A1 patent drawingFigure 2
  • EP4567377A1 patent drawingFigure 3

AI summary

The invention relates to a method (1000, 1001) for localizing a target position (226), in particular a working position, a position of a construction robot (10), or a position of a portable device, on a construction site (200), for example a building construction site (200) or a civil engineering construction site (200), using a localization device (32). The localization device (32) roughly localizes the target position (226), i.e., determines a construction site section (210) of the construction site (200) in which the target position (226) is located. This can improve the reliability of localizations. The invention further relates to a localization device (32), a computer program product (30), and a construction robot (10).