Elevator systems
An elevator system ( 201 ) includes an elevator car ( 203 ), a controller ( 215 ), a position reference system ( 234; 213 ) configured to provide a position of the elevator car ( 203 ) and at least one safety device ( 230 ) configured to indicate a potential hazard within the elevator system ( 201 ). When the actual position of the elevator car ( 203 ) cannot be determined using the position reference system ( 234 ), the controller ( 215 ) is configured to calculate at least one potential position of the elevator car ( 203 ) based on an assumed motion profile ( 237 ). The controller is configured to allow the elevator car ( 203 ) to move whilst no safety device ( 230 ), which corresponds to the at least one potential position of elevator car ( 203 ) is triggered and to stop movement of the elevator car ( 203 ) when a safety device ( 230 ) which corresponds to the at least one potential position of the elevator car is triggered.
1 . An elevator system ( 201 ) comprising:
an elevator car ( 203 ) arranged within an elevator shaft ( 217 );
a controller ( 215 ) configured to control movement of the elevator car ( 203 );
a position reference system ( 234 ; 213 ) configured to provide a position of the elevator car ( 203 ) within the elevator shaft; and
at least one safety device ( 230 ) configured to indicate, when triggered, a potential hazard within the elevator system ( 201 );
wherein when an actual position of the elevator car ( 203 ) cannot be determined using the position reference system ( 234 ; 213 ), the controller ( 215 ) is configured to:
calculate at least one potential position ( 248 ) of the elevator car ( 203 ) based on an assumed motion profile ( 237 ) of the elevator car ( 203 ); and
allow the elevator car ( 203 ) to move whilst no safety device ( 230 ), which corresponds to the at least one potential position ( 248 ) of the elevator car ( 203 ) is triggered; and
stop movement of the elevator car ( 203 ) when a safety device ( 230 ) which corresponds to the at least one potential position of the elevator car is triggered;
wherein the at least one safety device ( 230 ) comprises a virtual upper limit switch and a virtual lower limit switch, wherein the virtual upper limit switch or the virtual lower limit switch are automatically triggered when the at least one potential position ( 248 ) of the elevator car ( 203 ) corresponds to the uppermost or lowermost portion of the elevator shaft ( 217 ), respectively.
2 . The elevator system ( 201 ) as claimed in claim 1 , wherein the assumed motion profile ( 237 ) comprises an elevator car speed component ( 239 ) which comprises a maximum possible speed of the elevator car ( 203 ).
3 . The elevator system ( 201 ) as claimed in claim 1 , wherein the motion profile ( 237 ) comprises a direction of travel ( 241 ) component of the elevator car ( 203 ).
4 . The elevator system ( 201 ) as claimed in claim 1 , wherein the at least one potential position ( 248 ) of the elevator car ( 203 ) comprises a plurality of potential positions ( 248 ).
5 . The elevator system as claimed in claim 1 , wherein calculating the at least one potential position comprises calculating the at least one potential position periodically.
6 . An elevator system ( 201 ) as claimed in claim 1 , wherein each of the at least one potential position ( 248 ) corresponds to at least one positional zone within the elevator shaft ( 217 ).
7 . The elevator system ( 201 ) as claimed in claim 1 , wherein the
position reference system ( 234 ; 213 ) comprises an absolute position reference system ( 234 ) configured to provide an absolute position of the elevator car ( 203 ) within the elevator shaft ( 217 ).
8 . The elevator system ( 201 ) as claimed in claim 1 , wherein the at least one safety device ( 230 ) comprises a plurality of safety devices.
9 . A method of controlling the operation of an elevator car ( 203 ) within an elevator shaft ( 217 ) comprising a plurality of safety devices ( 230 ) configured to indicate a hazard in the elevator system ( 201 ), the method comprising:
monitoring a position of the elevator car ( 203 ) using a position reference system ( 234 ; 213 );
when an actual position of the elevator car ( 203 ) cannot be determined from the position reference system ( 234 ; 213 ), calculating at least one potential position ( 248 ) of the elevator car ( 203 ) based on an assumed motion profile ( 237 ) of the elevator car ( 203 ); and
allowing the elevator car ( 203 ) to move when no safety device ( 230 ) is triggered which corresponds to the at least one potential position ( 248 ) of the elevator car ( 203 ), and stopping the elevator car ( 203 ) from moving when a safety device ( 230 ) is triggered which corresponds to the at least one potential position ( 248 ) of the elevator car ( 203 );
wherein the plurality of safety devices ( 230 ) comprise a virtual upper limit switch and a virtual lower limit switch, wherein the virtual upper limit switch or the virtual lower limit switch are automatically triggered when the at least one potential position ( 248 ) of the elevator car ( 203 ) corresponds to the uppermost or lowermost portion of the elevator shaft ( 217 ), respectively.
10 . The method as claimed in claim 9 , wherein the assumed motion profile ( 237 ) comprises an elevator car speed ( 239 ) comprising a maximum possible speed of the elevator car ( 203 ).
11 . The method as claimed in claim 9 , wherein the assumed motion profile ( 237 ) comprises a direction of movement component ( 241 ).
12 . The method as claimed in claim 9 , wherein calculating the at least one potential position ( 248 ) comprises calculating a plurality of potential positions ( 248 ).
13 . The method as claimed in claim 9 , wherein the at least one potential position ( 248 ) corresponds to positional zones ( 248 ) within the elevator shaft ( 217 ).
14 . A computer program product stored on a non-transitory computer readable medium comprising computer-executable instructions which, when read by a machine, cause the machine to perform the method according to claim 9 .