Optical Multi-Turn Position Sensor for Magnetic Brake Environments
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Solution Overview
Problem
Position transmitter devices used in the vicinity of magnetic brakes often experience erroneous switching pulses due to magnetic field coupling, leading to inaccurate position detection.
Innovation Solution
A position transmitter design that utilizes optical sensor arrangements for both single-turn and multi-turn position detection, eliminating the need for magnetic fields and reducing component count and energy consumption through an integrated optical system with variable duty cycle operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If magnetic sensor arrangements are used for multi-turn position detection, then position detection can be achieved, but erroneous switching pulses occur due to magnetic field coupling from magnetic brakes
Solution Approach 1:
The patent replaces magnetic sensor arrangements with optical sensor arrangements for multi-turn position detection. This substitution eliminates the harmful interaction with magnetic fields from magnetic brakes, as optical sensors detect position using light rather than magnetic fields, thereby preventing erroneous switching pulses while maintaining detection accuracy
Solution Approach 2:
The patent introduces an optical intermediary (light) as the medium for detecting multi-turn position, replacing the direct magnetic field interaction. The optical sensor arrangement uses light to detect position changes without being affected by magnetic fields, serving as an intermediary that transfers position information without magnetic interference
2Loss of information
If separate magnetic sensor arrangements are used for single-turn and multi-turn detection, then comprehensive position information is obtained, but device complexity and component count increase
Solution Approach 1:
The patent makes the optical sensor arrangement universal by using it for both single-turn and multi-turn position detection. The same optical sensor can track position continuously whether the shaft rotates once or multiple times, eliminating the need for separate magnetic sensor arrangements and reducing overall device complexity while maintaining complete position information
Solution Approach 2:
The patent merges the functions of single-turn and multi-turn detection into a single optical sensor arrangement. By combining these detection capabilities in one unified optical system rather than using separate magnetic sensor arrangements, the patent reduces component count and simplifies the overall device structure
3Duration of action of moving object
If magnetic sensor arrangements are permanently energized to maintain multi-turn acquisition, then continuous position tracking is possible, but energy consumption increases
Solution Approach 1:
The patent implements periodic action by using a battery to power the optical sensor arrangement only when needed for multi-turn tracking, rather than permanent energization. The system can switch between powered and unpowered states, activating the optical sensors periodically or as needed, which significantly reduces energy consumption while maintaining continuous tracking capability when power is available
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 optical design ensures position detection insensitivity to magnetic fields, increases durability, and reduces energy consumption by using photodiodes with negligible energy consumption and variable LED operation, enhancing reliability and service life.
Implementation Method 1
The single-turn position is detected optically, i.e. a scale connected to the shaft influences the signals of an array of photodiodes, which are illuminated by an LED
Data Source
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AI summary
The present invention relates to position sensors for detecting the position of a shaft rotatable about an axis of rotation, comprising a first optical sensor arrangement for detecting the single-turn position of the shaft and a second optical sensor arrangement for detecting the multi-turn position of the shaft.