Passenger Conveyor Speed Deviation Brake Control
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Solution Overview
Problem
Conventional passenger conveyor systems, such as escalators and moving ramps, face safety risks due to undetected failures in the connection between the motor and drive shaft, which can lead to rapid movement and potential injuries, as existing solutions fail to reliably and quickly detect such issues.
Innovation Solution
A passenger conveyor system equipped with a control method that utilizes two sensing arrangements to monitor the rotation speed of the motor and drive shaft, detecting deviations and activating a brake if predefined criteria are met, thereby preventing unsafe conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional passenger conveyor systems are used without enhanced monitoring, then the system structure remains simple, but safety and reliability deteriorate due to undetected failures in motor-drive shaft connection
Solution Approach 1:
The patent implements feedback by continuously monitoring the rotational speeds of both the motor and drive shaft using sensing arrangements, comparing the values to detect deviations, and activating the brake system when failures are detected. This closed-loop monitoring system enhances safety by providing real-time detection of connection failures between the motor and drive shaft, allowing timely intervention before dangerous conditions occur.
2Measurement precision
If single sensing arrangement is used to monitor motor rotation speed, then device complexity is reduced, but measurement precision and detection reliability deteriorate
Solution Approach 1:
The patent applies segmentation by dividing the monitoring function into separate sensing arrangements: one for monitoring motor rotation speed and another for monitoring drive shaft rotation speed. This segmentation allows independent optimization of each sensor's performance and enables cross-validation of measurements, thereby improving overall detection precision and reliability without requiring a single complex all-purpose sensing system.
Solution Approach 2:
The control unit acts as an intermediary that receives rotational speed data from both sensing arrangements, processes the information, compares the motor and drive shaft speeds, and triggers the brake system when deviations indicate failure. This intermediary processing layer enhances measurement precision by synthesizing data from multiple sources and detecting anomalies that would be invisible to a single sensor.
3Object-affected harmful factors
If failure detection is performed late in the conveyor operation, then system complexity is minimized, but harmful factors increase due to prolonged unsafe conditions
Solution Approach 1:
The patent implements preliminary action by continuously monitoring motor and drive shaft rotational speeds from the start of operation, rather than performing checks only after potential failures occur. The system is pre-configured with sensing arrangements and control logic that immediately detect deviations indicating connection failure, enabling timely activation of the brake system before dangerous rushing conditions develop and passengers are put at risk.
Data Source
Figure 1~2
Figure 3~5
AI summary
The invention relates to a method for controlling a passenger conveyor (1), which passenger conveyor (1) comprises an endless band (2) of conveying elements (2a), the endless band (2) comprising an inclined conveying section (1); a drive shaft (3) arranged to drive the endless band (2) of conveying elements (2a) when rotated; a motor (4) for rotating the drive shaft (3); a first sensing arrangement (5) for sensing a rotation speed of the motor (4); a brake (7;7') activatable to act directly on the drive shaft (3) or an element (8;10) fixedly connected to it for stopping rotation of the drive shaft (3); a control system (9); wherein the method comprises rotating the drive shaft (3) with the motor (4); and sensing rotation speed of the motor (4) with the first sensing arrangement (5). The passenger conveyor (1) comprises a second sensing arrangement (6;6') for sensing rotation speed of the drive shaft (3); and the method comprises sensing rotation speed of the drive shaft (3) with the second sensing arrangement (6;6'); and detecting deviation between the rotation speed of the motor (4) and the rotation speed of the drive shaft (3) or a multifold thereof; and activating the brake (7;7') for stopping rotation of the drive shaft (3) if deviation, in particular deviation meeting predefined criteria, is detected between the rotation speed of the motor (4) and the rotation speed of the drive shaft (3) or a multifold thereof, wherein said multifold equals to the rotation speed of the drive shaft (3) multiplied with a preset factor n, wherein n preferably equals to transmission ratio between the drive shaft (3) and the motor (4). The invention relates to a passenger conveyor (1) implementing the method.