Compensated Angular Displacement Measurement Using Inertial Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Geodetic instruments, such as total stations, face inaccuracies in measuring angular displacement during high angular acceleration due to torsional reactions, which are not effectively accounted for by existing methods.
Innovation Solution
The implementation of a combination of an angle resolver and an inertial sensor to provide compensated angle measurement signals, accounting for torsional reactions and improving accuracy and control during high angular acceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high angular acceleration is used for faster repositioning, then productivity is improved, but measurement precision deteriorates due to torsional reactions
Solution Approach 1:
An inertial sensor is introduced as an intermediary measurement device that is insensitive to torsional reactions. The inertial sensor measures the true angular position of the rotating component relative to an external reference, while a separate torque sensor measures the torsional reaction. These measurements are combined through signal processing to compensate for the measurement errors caused by high angular acceleration, enabling both fast repositioning and accurate measurement.
Solution Approach 2:
The system implements feedback by continuously monitoring the torsional reaction torque with a torque sensor and using this information to compensate for measurement errors in real-time. The compensated angular position signal is fed back to the control system to maintain accurate positioning even during high-speed operations, resolving the contradiction between speed and measurement accuracy.
2Measurement precision
If torque compensation is implemented, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple measurement functions into an integrated system where the inertial sensor and torque sensor work together to provide compensated angular position measurements. The signal processing circuitry merges the outputs from both sensors, using the torque measurement to correct the angular position measurement, thereby achieving high precision without requiring a single overly complex sensor system.
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 solution enables rapid and accurate measurement of angular position relative to external references, stabilizing control loops and facilitating faster repositioning with improved accuracy and controllability.
Implementation Method 1
an inertial sensor, such as a gyroscope or an accelerometer, or a group of accelerometers
Implementation Method 2
An angle sensor 145, such as an angle encoder or magnetic or capacitive angle resolver, produces an azimuth measurement signal representing angular position of the alidade relative to the base
Implementation Method 3
The torque T1 of the alidade 115 and the opposing torque T2 imposed on the base 105 and on the tripod 110 are shown in FIG. 1
Data Source
AI summary
There is disclosed methods and apparatus for compensated measurement of angular displacement within an instrument (600), such as a total station. Improved and compensated measurement of angular displacement is obtained by using a combination of e.g. an angular resolver (145) and an inertial sensor (645). A compensated angular position measurement is produced by combining at least portions of the output signals obtained from the angular resolver and the inertial sensor, respectively.