Geodetic Instrument Drift Reduction via Oscillatory Motor Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Geodetic instruments experience drift due to hysteresis in the holding arrangement, leading to uncertainty and errors in measurements over time, particularly in the azimuthal orientation.
Innovation Solution
A geodetic instrument with a motorized positioning arrangement and a controller that induces oscillatory rotational and translational movements to quickly release frictional tension in the holding arrangement, reducing or eliminating hysteresis and subsequent drift.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the geodetic instrument is mounted on a holding arrangement with adjustment joints, then the instrument can be positioned and leveled, but frictional tension builds up in the joints causing hysteresis and drift over time
Solution Approach 1:
The patent applies mechanical vibration by inducing oscillatory movements in the holding arrangement through the motorized positioning arrangement. These vibrations quickly release frictional tension built up in adjustment joints, thereby reducing hysteresis and preventing drift in the backsight reference over time, while maintaining the positioning capability provided by the adjustment joints
2Reliability
If frictional tension is released quickly in the holding arrangement, then hysteresis and drift are reduced, but additional mechanical components and control mechanisms are required
Solution Approach 1:
The patent makes the motorized positioning arrangement serve a dual function: its primary function for aiming the line of sight and a secondary function for inducing vibrations to release frictional tension. This multi-functionality approach reduces device complexity by reusing existing components rather than adding separate vibration-inducing mechanisms
Solution Approach 2:
The system uses its own motorized positioning arrangement to generate the vibrations needed to maintain measurement stability, rather than requiring an external vibration source. The instrument serves itself by utilizing its positioning motors to periodically release frictional tension in the holding arrangement
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 solution effectively reduces or eliminates hysteresis-related drift, enhancing the reliability and accuracy of geodetic instrument measurements by quickly releasing frictional tension in the holding arrangement, thereby stabilizing the instrument's orientation.
Implementation Method 1
Frictional tension may build up in one or more parts of the holding arrangement, for example when the holding arrangement is assembled and/or pitched at a new location
Implementation Method 2
The built up frictional tension may lead to a so called hysteresis in the holding arrangement
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present disclosure provides a geodetic instrument (100) adapted to determine a direction and/or a distance to a target. The geodetic instrument includes an attachment device (120) for attaching the geodetic instrument to a holding arrangement (122); a motorized positioning arrangement for aiming a line of sight (L) of the geodetic instrument via rotation and/or translation of at least a part of the motorized position arrangement relative to the holding arrangement, and a controller (130). The controller is configured to, upon determining that a setting up of the geodetic instrument is required, provide a control sequence to the motorized positioning arrangement for causing a series of oscillatory rotational and/or translational movements of the at least a part of the motorized positioning arrangement. A method of setting up a geodetic instrument is also provided.