Multi-car elevator primary motion control transition
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Solution Overview
Problem
In self-propelled elevator systems, the maximum elevator car velocity is limited by the speed at which commands can be issued and processed while the cars are in motion, affecting smooth motion control in multi-car ropeless elevator systems.
Innovation Solution
A system where a primary motion control is designated to command drives via a local communication network, transitioning between motion controls as the elevator car moves, ensuring consistent latency and efficient force impartation using a linear propulsion system with a primary and secondary portion of motor segments, and feedback loops for velocity and position control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If multiple motion controls continuously communicate via a long-distance hoistway communication network, then the system can maintain centralized control, but the command processing latency increases and maximum velocity is limited
Solution Approach 1:
The patent introduces a primary motion control as an intermediary between the controller and the drive system. The primary motion control receives commands from the controller via the hoistway communication network and translates them into drive commands via a local communication network, eliminating the need for continuous long-distance communication during motion control operations.
Solution Approach 2:
The control system is segmented into distinct functional layers: a controller for high-level decision-making, a primary motion control for command translation and local coordination, and drive controls for execution. This segmentation allows different communication protocols and distances to be optimized for different functional requirements.
2Reliability
If a single primary motion control continuously commands the drive system, then consistent latency is achieved, but the system complexity increases due to the need for dynamic designation transitions
Solution Approach 1:
The system dynamically designates which motion control serves as the primary controller based on the elevator car's position. As the car moves between hoistway sections, the primary motion control designation transitions smoothly to the next adjacent motion control, maintaining consistent local communication latency while adapting to changing operational conditions.
Solution Approach 2:
The system pre-establishes communication pathways and control designations for each hoistway section. Before the elevator car enters a new section, the appropriate motion control is designated as primary, ensuring seamless transitions without interruption to the control signal chain.
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 enhances the smooth motion control and velocity of elevator cars by maintaining consistent latency and efficient communication, overcoming the limitations of command processing speed in existing systems.
Implementation Method 1
One type of elevator propulsion system for ropeless elevator systems includes a linear motor, such as an electrically-controlled linear synchronous motor that propels elevator cars between linear motor segments.
Data Source
AI summary
An elevator system with an elevator car 14, a linear propulsion system to impart force to the elevator car in a hoistway 11, a hoistway communication network 106, 206, a local communication network 110, 210, 310 and motion controls. One of the motion controls proximate to the elevator car is designated as a primary control 61 operable to command at least one drive 42A-42F via the local communication network. The at least one drive is coupled to one or more motor segments 22 of the linear propulsion system. The elevator system further includes a controller 46 operable to command the primary control via the hoistway communication network to reposition the elevator car within the hoistway. The designation of the primary control transitions between the motion controls as the elevator car moves in the hoistway.