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US 4,750,591 AGranted
Elevator car door and motion sequence monitoring apparatus and method
AssigneeOtis Elevator Company
InventorsSteven D. Coste, Gregory A. Schienda
Life of this patent
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Abstract
An elevator monitoring apparatus and method are disclosed in which an elevator is modeled as operating in a closed loop chain of normal operating states from which message initiating transitions to abnormal states causes the latest to occur of a selected number of monitored events are recovered from a storage buffer as an aid to an analysis of an abnormal state. Door and motion closed loop chain state machines are disclosed as effective tools for abnormal event detection, especially for a state machine approach implemented within an elevator controller.
Claims5
Apparatus for monitoring an elevator, comprising:
- signal processor means, for monitoring the states of a plurality of two-state parameter signals, each indicative of one of a corresponding plurality of elevator parameters, said signal processor means determining the identity of an elevator operating state, for an elevator car, which normally operates sequentially from state to state in a closed loop sequential chain of linked normal operating states, by detecting the satisfication of a transition criterion defining a transition from an immediately preceding operating state or an immediately succeeding operating state by detecting the parameter signal state or states, alone or in combination, of one or more sensed parameter signals defining the satisfied transition criterion, each criterion indicating either a transition to a normal operating state in the chain or to an abnormal operating state, and providing selected message signals in the presence of corresponding selected transitions;
- and
- an event buffer, responsive to a selected number of the latest to occur of selected parameter signal state changes, for storing signals indicative of said latest state changes, said event buffer responsive to said message signals for providing accompanying buffer message signals corresponding to the stored signals.
A method for monitoring an elevator car, comprising the steps of:
- monitoring the states of a plurality of two-state parameter signals, each indicative of one of a corresponding plurality of elevator parameters;
- determining the identity of a car door state, for an elevator car door which normally operates sequentially from state to state in a closed loop sequential chain of linked normal operating car door states, by detecting the satisfaction of a transition criterion defining a transition from an immediately preceding car door state or to an immediately succeeding car door state by detecting the parameter signal state or states, alone or in combination, of one or more sensed parameter signals defining the satisfied transition criterion, each criterion indicating either a transition to a normal car door state in the chain or to an abnormal car door state;
- determining the identity of a motion state of the elevator car, which normally executes movements sequentially from state to state in a closed loop sequential chain of linked normal operating motion states, by detecting the satisfaction of a transition criterion defining a transition from an immediately preceding motion state or to an immediately succeeding motion state by detecting the parameter signal state or states, alone or in combination, of one or more sensed parameter signals defining the satisfied transition criterion, each criterion indicating either a transition to a normal motion state in the chain or to an abnormal motion state;
- and
- providing selected message signals in response to the detection of corresponding selected transitions.
2 more elements
Apparatus for monitoring an elevator, comprising:
- signal processor means, for monitoring the states of a plurality of two-state parameter signals, each indicative of one of a corresponding plurality of elevator parameters,
- said signal processor means determining the identity of a car door state, for an elevator car door, which normally operates sequentially from state to state in a closed loop sequential chain of linked normal operating car door states, by detecting the satisfaction of a transition criterion defining a transition from an immediately preceding car door state or an immediately succeeding car door state by detecting the parameter signal state or states, alone or in combination, of one or more sensed parameter signals defining the satisfied transition criterion, each criterion indicating either a transition to a normal car door state in the chain or to an abnormal car door state, and providing selected car door message signals in the presence of corresponding selected transitions,
- said signal processor means determining the identity of the motion state of the elevator car, which normally executes movements sequentially from state to state in a closed loop sequential chain of linked normal operating motion states, by detecting the satisfaction of a transition criterion defining a transition from an immediately preceding motion state or to an immediately succeeding motion state by detecting the parameter signal state or states, alone or in combination, of one or more sensed parameter signals defining the satisfied transition criterion, each criterion indicating either a transition to a normal motion state in the chain or to an abnormal motion state, and providing selected motion message signals in the presence of corresponding selected transitions;
- and
- communication element means, responsive to message signals for transmission thereof.
2 more elements
Dependencies are inferred from the claim text.