Construction Machine Path Control During GNSS Signal Loss
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Solution Overview
Problem
Self-propelled construction machines face challenges in maintaining accurate movement along a target travel path when satellite signals from the GNSS system are disrupted, leading to potential machine shutdowns.
Innovation Solution
The integration of a position-determination system with both a navigation satellite system receiver and a reflector for optical measurement by a total station, allowing the machine to switch to a total station control mode for continued operation independent of GNSS signals, using processor calculations and data exchange to determine and maintain accurate positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the construction machine uses GNSS satellite signals for position determination, then automatic control along the target travel path is achieved, but the control is disrupted when satellite signals are blocked (e.g., under bridges or in tunnels)
Solution Approach 1:
The patent introduces a total station as an intermediary positioning system that can operate independently of satellite signals. The total station receives rod data from a measurement rod carried by the construction machine and converts it into position information in the global coordinate system, serving as a mediator when GNSS signals are unavailable.
Solution Approach 2:
The control system is designed to support multiple positioning methods (GNSS and total station) within a single unified control framework. The system can automatically switch between positioning modes depending on signal availability, making the control system versatile across different working environments.
2Reliability
If the construction machine switches to total station control mode, then operation continues without satellite signals, but the coordinate systems of GNSS and total station must be calibrated and transformed
Solution Approach 1:
The patent performs preliminary calibration of the total station coordinate system with the GNSS coordinate system before actual construction work begins. By pre-establishing the transformation relationship between the two coordinate systems, the system eliminates the need for complex real-time transformations during operation, simplifying the control process.
3Reliability
If a dual positioning system (GNSS and total station) is integrated, then positioning reliability improves under signal disruption, but the system complexity and calibration requirements increase
Solution Approach 1:
The patent implements a dynamic positioning system that can automatically switch between GNSS and total station modes based on signal availability. The system dynamically adjusts the positioning method being used, optimizing reliability while managing complexity through automated mode selection rather than requiring manual intervention.
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
Enables the self-propelled construction machine to maintain high accuracy in moving along a target travel path even when GNSS signals are disrupted, ensuring continuous operation without the need for satellite signals, by calibrating the total station coordinate system and using it for control.
Implementation Method 1
a reflector for optical measurement by means of a total station
Data Source
AI summary
A construction machine system comprises a self-propelled construction machine and a total station. The construction machine possesses a machine frame, a drive means and a working means for altering the terrain. A position-determination means determines the position of a reference point on the machine in a first coordinate system independent of the machine. The position-determination means receives satellite signals from a global navigation satellite system (GNSS), wherein in normal operation the machine is controlled using the GNSS such that a reference point on the machine moves along a set target travel path. In a total station control mode, the machine is controlled without the GNSS and only using the total station based on a position of the standpoint and orientation of the total station ascertained in the GNSS control mode, and the position-determination of the construction machine occurs in a second coordinate system based on the total station.