Hybrid Position Encoder and Inertial Sensor for High-Speed Measurement
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Solution Overview
Problem
Existing attitude determination devices for coordinate measuring machines and geodetic surveying systems face challenges in achieving high measurement speed without compromising measurement accuracy, and require complex mechanics and electronics, making them costly.
Innovation Solution
A position determination device that combines a position encoder with an inertial measuring unit, where the inertial unit generates high-rate position data used to correct and enhance the position data from the encoder, allowing for increased measurement speed while maintaining accuracy through data correlation using algorithms like the Kalman filter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If high measurement speed is achieved using complex mechanics and electronics, then measurement speed increases, but device complexity and cost increase
Solution Approach 1:
The patent combines a position encoder (providing accurate but slow measurements) with an inertial measuring unit (providing fast but less accurate measurements) into a hybrid system. The evaluation unit merges data from both sources, using the inertial data to fill temporal gaps between encoder measurements, thereby achieving high measurement speeds without requiring complex high-speed encoder mechanics and electronics.
2Productivity
If high measurement speed is achieved, then productivity increases, but measurement precision deteriorates
Solution Approach 1:
The evaluation unit continuously compares inertial measuring unit data with position encoder data, using the accurate encoder measurements as reference feedback to correct and calibrate the inertial measurements. This feedback mechanism ensures that even at high measurement speeds (1000 Hz or more), the position determination maintains the accuracy characteristics of the encoder by periodically correcting drift in the inertial data.
3Productivity
If high measurement speed is achieved through complex systems, then measurement rate increases, but ease of manufacture deteriorates
Solution Approach 1:
The patent employs a standard position encoder that can operate at lower speeds (1 Hz to 20 Hz) without requiring expensive high-speed variants. By using the inexpensive, slower encoder combined with a relatively cheap inertial measuring unit, the system achieves high measurement rates (1000 Hz or more) without investing in costly high-speed encoder hardware, thereby improving ease of manufacture.
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 combination enables a high measurement rate of up to 1000 Hz or more with maintained accuracy, allowing the use of less expensive, slower position encoders and ensuring continuous high accuracy by repetitive data comparison.
Implementation Method 1
at least one inertial measuring unit for measuring accelerations and for determining position changes from them
Implementation Method 2
optical-electronic methods (ie based on inductive, capacitive or optical)
Implementation Method 3
electronic-magnetic, electronic and optical-electronic methods
Implementation Method 4
Data processing using a Kalman filter, for example, is suitable for correlating the first and the second position determination data
Data Source
Figure 1a~1c
Figure 2
Figure 3
AI summary
The invention relates to a position determination device for determining the position of two components (10, 11) relative to each other, comprising at least one position encoder (60) with a read head (71) in conjunction with a code (61) for generating first position determination data at a first measurement frequency. According to the invention, at least one inertial measuring unit (51) is arranged for the additional determination of translational and/or rotational accelerations of at least one of the two components and for the subsequent generation of second position determination data with respect to the position at a second measurement rate that is higher than the first measurement rate.For the determination of the position by an evaluation unit, it is now provided that the first position determination data generated by the at least one position encoder (60) and the second position determination data (120) generated by the at least one inertial measuring unit (51, 52, 53, 54, 55, 56, 57, 58, 59, 59', 59") are recorded, correlated with each other and the position is determined from this with a third measurement rate that is at least higher than the first measurement rate.