Elevator Speed Control via Load-Dependent Safety Limits
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Solution Overview
Problem
Elevator systems face limitations in transport capacity due to fixed speed settings that do not account for varying loads, leading to inefficient operation and potential safety risks.
Innovation Solution
Implementing a load/weight sensor and electronic safety controller that dynamically adjust the speed limit of the elevator car based on its load and weight, allowing for increased rated speeds while ensuring safety through activation of a safety gear when exceeded, and incorporating direction and position-based adjustments for enhanced control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the speed limit of the elevator car is increased to enhance transport capacity, then the productivity is improved, but the safety risk increases
Solution Approach 1:
The patent implements dynamic speed adjustment by making the speed limit variable based on real-time load conditions. The electronic safety controller continuously monitors the load/weight sensor data and adjusts the speed limit accordingly, transitioning from a static fixed speed system to a dynamic adaptive system that optimizes both productivity and safety
Solution Approach 2:
The patent changes the parameter of speed limit from a constant value to a variable value that depends on load conditions. By setting different speed limits based on detected load/weight, the system adapts operational parameters to current conditions, allowing higher speeds when safe and lower speeds when necessary
2Productivity
If a fixed speed limit is used for all load conditions, then the device complexity is reduced, but the productivity is limited
Solution Approach 1:
The patent implements a feedback mechanism where the load/weight sensor continuously monitors the elevator car load and feeds this information to the electronic safety controller. The controller then adjusts the speed limit based on this feedback, creating a closed-loop control system that automatically optimizes speed without requiring complex manual intervention
Solution Approach 2:
The system performs self-adjustment of speed limits based on its own operational conditions. The electronic safety controller automatically processes load information and modifies speed parameters without external intervention, enabling the system to self-optimize its performance based on real-time conditions
Data Source
AI summary
An elevator system (2) comprises a hoistway (4) extending between a plurality of landings (8a, 8b, 8c); an elevator car (60) configured for moving along the hoistway (4) between the plurality of landings (8a, 8b, 8c); a load/weight sensor (44) configured for detecting the load of the elevator car (60); a speed detector (34) configured for detecting the speed of the elevator car (60); and an elevator safety system. The elevator safety system comprises a safety gear (20) configured for stopping, upon activation, any movement of the elevator car (60); and an electronic safety controller (30) configured for activating the safety gear (20) when the detected speed of the elevator car (60) exceeds a set speed limit. The electronic safety controller (30) is configured for setting the speed limit as a function of the load detected by the load/weight sensor (44).