Elevator Braking Assembly Dynamic G-Force Control
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Solution Overview
Problem
Conventional elevator braking systems apply a fixed deceleration force that can result in harsh stops and prolonged confinement of passengers when an over-speed event occurs, as the deceleration varies with the load, leading to unpleasant experiences and potential safety issues.
Innovation Solution
An electronic braking assembly that adjusts deceleration based on load and position sensors to maintain a predetermined g-force threshold, using an engagement member that applies a frictional force controlled by electrical current to ensure a smooth stop at a floor landing, regardless of the load, thereby preventing excessive deceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a fixed stiffness spring is used in the braking block to stop the elevator car with a deceleration of approximately 1 g-force when the car is at full load, then the braking force is sufficient for full load conditions, but the deceleration becomes excessively high and causes harsh stops when the car is lightly loaded
Solution Approach 1:
The patent replaces the fixed stiffness spring with an electronically controlled braking assembly that dynamically adjusts the braking force based on real-time load detection. The controller modulates the engagement force of the engagement member against the guide rail according to the detected load, ensuring optimal deceleration profiles for both full load and light load conditions, thereby eliminating harsh stops while maintaining sufficient braking capability.
Solution Approach 2:
The system changes the braking parameter (engagement force) dynamically based on load conditions. The electronic controller adjusts the degree of engagement between the engagement member and guide rail, varying the normal force applied according to the detected load, which directly controls the frictional braking force and resulting deceleration to maintain passenger comfort across all loading scenarios.
2Loss of time
If the braking block applies high deceleration force to stop the elevator car quickly during an over-speed event, then the stopping time is reduced, but the passengers experience harsh stops and potential safety issues
Solution Approach 1:
The system employs continuous feedback from load sensors and speed sensors to the electronic controller during the braking process. The controller monitors the actual deceleration and load conditions in real-time, adjusting the engagement force dynamically to maintain deceleration within the comfortable and safe range (0.1g to 1.0g), thereby preventing both excessive stopping time and harmful high deceleration effects on passengers.
3Reliability
If the braking assembly is activated during an over-speed event, then the elevator car is stopped, but the car may be halted between floor landings causing prolonged confinement of passengers
Solution Approach 1:
The electronic controller calculates the optimal braking initiation point and deceleration profile in advance based on the car's position, speed, and load conditions. By determining the precise engagement force and timing required to stop exactly at the nearest floor landing, the system prevents unnecessary stops between floors, thereby reducing passenger confinement time while maintaining reliable over-speed protection.
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 system ensures a comfortable and safe stop for passengers by maintaining a consistent deceleration below a predetermined g-force threshold, allowing for smooth deceleration and preventing prolonged confinement between floor landings.
Implementation Method 1
an amount of the frictional force is based on an amount of electrical current output by the electronic braking assembly controller
Implementation Method 2
the braking assembly includes an engagement member configured to apply a frictional force when operating in the engagement mode
Data Source
AI summary
An elevator system (100) includes an elevator car (102) that is configured to travel along a guide rail (104), and a braking assembly (116) coupled to the elevator car (102). The braking assembly (116) is configured to selectively operate in a disengagement mode that allows the elevator car (102) to travel along the guide rail (104), and an engagement mode that inhibits the elevator car (102) from traveling along the guide rail (104). The electronic braking assembly controller (128) is in signal communication with the braking assembly (116) and is configured to generate an electronic braking signal that activates the engagement mode of the braking assembly (116). When the engagement mode is activated, the elevator car (102) decelerates without exceeding a predetermined g-force (g) threshold regardless as to whether a load applied to the elevator car (102) changes such that the elevator car (102) is stopped at a floor landing (106).