Elevator Brake Current Sensing for Faster Re-Engagement
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Solution Overview
Problem
Conventional elevator systems face challenges in quickly and reliably stopping the elevator car during displacement movements, especially when the car is moving at high speeds or when the doors are not fully closed, which can lead to unsafe situations.
Innovation Solution
A method for controlling the elevator brake that involves applying an initial electrical voltage to the electromagnet, measuring the current supplied, and reducing the voltage to a holding voltage based on the characteristic temporal behavior of the current as the armature moves from the braking position to the release position, allowing for early reduction of energy stored in the electromagnet to quickly reactivate the brake.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the voltage applied to the electromagnet is reduced early to save energy, then energy consumption is reduced, but the brake activation time increases
Solution Approach 1:
The system monitors the current through the electromagnet and detects when it reaches a predetermined threshold value, using this feedback signal to trigger the voltage reduction. This ensures the voltage is reduced at the optimal moment when the armature has already started moving, balancing energy savings with brake response time.
Solution Approach 2:
The patent replaces mechanical position sensors with an electrical measurement approach, using current monitoring to infer armature position and control the voltage reduction timing. This eliminates complex mechanical feedback mechanisms while achieving precise control.
2Ease of operation
If conventional brake control is used, then the system is simple to operate, but the brake activation time is excessive and safety is compromised
Solution Approach 1:
The brake control system uses its own current characteristics to automatically determine when to reduce voltage, eliminating the need for external sensors or complex control mechanisms. The system self-regulates based on its operational state, maintaining simplicity while improving response time.
3Measurement precision
If additional sensors are added to monitor armature position, then brake control precision is improved, but device complexity increases
Solution Approach 1:
The patent replaces mechanical position sensors with an electrical measurement approach, using current monitoring to infer armature position. The current through the electromagnet serves as an indirect but sufficient indicator of armature movement, eliminating the need for additional mechanical sensors and reducing system complexity.
Solution Approach 2:
The electrical current acts as an intermediary parameter that indirectly indicates armature position. Instead of directly measuring position, the system measures current which correlates with armature movement stage, providing sufficient control information without direct position sensing.
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 approach enables faster activation and reactivation of the brake, reducing the time required to stop the elevator car and preventing potential hazards by optimizing the voltage reduction process without the need for additional sensors or complex hardware, thus enhancing safety and efficiency.
Implementation Method 1
The brake has an armature, which is to be pulled by an electromagnet from a braking position to a release position against a spring force
Implementation Method 2
a brake, which has a spring element and an electromagnet
Data Source
Figure 1
Figure 2~3
AI summary
The invention relates to a method for controlling a brake (3) of an elevator system (1), and to a brake controller (25) controlling said method. The brake (3) in this case comprises an armature (15), which is drawn by an electromagnet (17) against a spring force into a release position in order to release the brake (3) from a brake position. The method comprises the following steps: applying an initial electric voltage to the electromagnet (17) and measuring an amperage I(t) then fed to the electromagnet (17); and reducing the voltage applied to the electromagnet (17) to a holding voltage in response to an identification of a typical behaviour over time of the measured amperage I(t) which occurs characteristically when the armature (15) is moved from the braking position into the release position. The method enables the brake (3) to be activated more quickly in certain situations from a released state into a braking state.