Multi-Tier Limit-Angle Protection Using Magnetic Sensing
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Solution Overview
Problem
Conventional limit-angle protection devices for rotation mechanisms are limited by contact-based mechanisms that increase complexity and are not capable of secure, stable protection, especially when dealing with large driving forces or varying angles, and existing solutions like US20040017187 require larger volumes and lack multi-tier security.
Innovation Solution
A multi-tier limit-angle protection device using non-contact magnetic induction with a first-axis potentiometer and limit-angle detecting module, featuring magnetic sensing elements and switch circuits, and a controller to determine rotation angles and stop motors when limits are exceeded, integrating analog and digital magnetic field sensing for reduced complexity and enhanced reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional mechanical stopper is used to restrain the angle of rotation, then the angle of rotation is limited, but the device cannot protect against damage from excessive driving force and may overload the mechanism
Solution Approach 1:
The patent replaces the conventional mechanical stopper with a non-contact magnetic sensing system. Hall elements detect the position of a magnet attached to the rotating mechanism, enabling angle monitoring without mechanical contact. This substitution eliminates wear and overload issues while maintaining angle limitation functionality, and enables protective power interruption capability.
Solution Approach 2:
The patent introduces a magnet as an intermediary element that mediates between the rotating mechanism and the Hall elements. The magnet's position relative to the Hall elements provides information about the rotation angle without requiring direct mechanical contact between the sensing system and the mechanism, thus preventing overload while maintaining control.
2Reliability
If a conventional limit switch is used to trigger at angular limits, then the rotation mechanism stops at the limit angle, but the system requires physical contact and intricate wiring loops
Solution Approach 1:
The patent replaces the contact-based limit switch with a non-contact magnetic sensing system using Hall elements. The Hall elements detect the magnet's position wirelessly through magnetic field induction, eliminating the need for mechanical contact and intricate wiring loops while maintaining reliable limit-angle detection and protection.
Solution Approach 2:
The patent uses magnetic field information as a copy of the mechanical position information. Instead of requiring physical contact to detect the limit angle, the Hall elements sense the magnetic field distribution that replicates the position data, enabling contactless detection and simplifying the system architecture.
3Measurement precision
If magnetic blocks with special shapes are used to achieve position-dependent linear relationship, then the Hall elements can generate accurate sinusoidal waves, but the device volume must increase to achieve large range of motion
Solution Approach 1:
The patent changes the magnetization direction parameter of the magnetic blocks to perpendicular relative to the rotation axis, rather than using special geometric shapes. This parameter change enables the generation of sinusoidal waves from the magnetic field strength variation, achieving accurate angular position measurement without increasing device volume.
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 provides secure, stable, and cost-effective limit-angle protection by reducing mechanism complexity, enhancing reliability, and allowing for software-adjusted limits, effectively preventing motor operation beyond defined angles without physical contact, thus preventing damage from excessive rotation.
Implementation Method 1
a first-axis sensing signal to be generated in accordance with an output of a variation in a strength of magnetic field induction of the first magnetic block relative to the first-axis potentiometer
Implementation Method 2
the angular or linear displacement is determined in accordance with a sinusoidal wave generated from two linear Hall elements (LHE)
Data Source
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AI summary
A multi-tier limit-angle protection device detects a rotation angle about a rotation axis of a driving apparatus to thereby control the operation of a driving motor of the driving apparatus. The multi-tier limit-angle protection device includes a first-axis potentiometer for generating a first-axis sensing signal, a first-axis limit-angle detecting module for generating a first-axis confirming signal, and a controller. The controller effectuates a first tier protection mechanism by determining whether a limit angle of the rotation axis is exceeded according to the first-axis sensing signal, effectuates a second tier protection mechanism by determining whether the first-axis potentiometer is operating well according to a first-axis confirming signal, and effectuates a third tier protection mechanism through its control over the driving motor. The multi-tier limit-angle protection device features integration of software and hardware to thereby preclude mechanism complexity and provide a multi-tier limit-angle protection mechanism.