US3851733A

US3851733A - Elevator system

Info

Publication number: US3851733A
Application number: US00340617A
Authority: US
Inventors: M Sackin; D Edison
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1973-03-12
Filing date: 1973-03-12
Publication date: 1974-12-03
Anticipated expiration: 1991-12-03
Also published as: JPS5047350A; ES424160A1; FR2221383B1; AU6652074A; JPS5848462B2; DE2411861A1; BE812215A; BR7401818A; CA995371A; DE2411861C2; IT1019601B; NL7403270A; FR2221383A1; GB1468063A

Abstract

A new and improved elevator system, and method of allocating calls and assigning cars in an elevator system to serve calls for elevator service. When a floor call is received, it is processed by adding it to the assignment register of at least one of the elevator cars, or by creating a demand signal relative to the call. The floor calls in the system are reprocessed in response to certain conditions, to determine if there is a closer suitable car to each of the floor calls than the car which presently has the call in its assignment register. When a closer suitable car is found the call is added to the assignment register of this closer car, and it is removed from any other assignment register in which it appears.

Description

ite States atent 1 [111 3,851,733

Sackin et al. Dec. 3, 1974 ELEVATOR SYSTEM Primary Examiner-Robert K. Schaefer [75] Inventors: Milton Sackin, Pittsburgh; David M. Assistant Examiner w' Duncanson Edison, Murrysvine, both of Pa. Attorney, Agent, or Firm-D. R. Lackey [73] Assignee: Westinghouse Electric Corporation,

Pittsburgh Pa, [57] ABSTRACT A new and improved elevator system, and method of [22] Flled' 1973 allocating calls and assigning cars in an elevator sys- [21] Appl. No.: 340,617 tern to serve calls for elevator service. When a floor call is received, it is processed by adding it to the assignment register of at least one of the elevator cars, or by Creating a demand Signal relative to the can The [58] Field 187/29 floor calls in the system are reprocessed in response to certain conditions, to determine if there is a closer [56] References Cited suitable car to each of the floor calls than the car which presently has the call in its assignment register.

UNITED STATES PATENTS When a closer suitable car is found the call is added to 3,443,668 '5/1969 Hall et a1, 187/29 the assignment register of this closer car, and it is re- L 5/1970 DC Lamutcrm 187/29 moved from any other assignment register in which it 3,587,786 6/1971 Savino 187/29 appears.

3 589,473 6/197] Kirsch et al 187/29.

30 Claims, 30 Drawing Figures INTERFACE TIMING umrr cm CALL F CONTROL 'ER To DOOR FLOOR HALL SELECTOR LANTERNS DOOR OPERATOR 54 I DISTANCE 49! I -PULSES Isl LANDING PULSE A '3 v DETECTOR 6 1Q H PULSE I [DETECTORI PATENTEL DEE 74 SHEET 01 or .18

80 INTERRuPT 4 INPUT FUNCTIONS EQBE INTERFACE TIMING 74 70 I PROCESSOR 1 'INTERFAOEI 72 I cORE MEMORY 4GE SYSTEM PROCESSOR g f OTHER CARS MOTOR INTERFACE 3o 22 H 4% I F |G.| TIMING 30m LANDING I CAR CALL UM". i .I H 6 CONTROL 'YK 7 1 HATCHWAY '52 TIMING-1 ?4 x l 35 44 TO 000R FLOOR HALL Y!" I OAR-OPERATOR SELECTOR I LANTERNS 5e DOOR 2nd LANDING OPERATOR I 54 5e MOTOR SPEED I I PATTERN 4O ,ONTROLLER GENERATOR J DISTANCE 24 50 I -PuLsEs ISI LANDING +J L l A ll 7 I 64 Q o v28 32 V 1 PULSE DETECTOR Pmmnm 31m STORE P C. STORE ACC READ INPUT I DECREMENT '50 TIME SET TIME= 32 BID Tl MER PROGRAM RETRIEVE ACC RETRIEVE Roe. RETURN osur1s v 222 SET TO ZERO: XBDR, DEMIND, DEMASJ'ODEM, UPK,DPK,UPTIM,

NCL,NTOD,MFU, NEXLZCCLZINIT CLEAR: CRA,CLR, CCLR, CL

ET BIT 5 OF XBDR BIT# N SET IN XBDR 240 242 JMP TO START) OF PROGRAM N (CHECK PATENTE; 953 74 saw as 0F 18 FIGZOA. P

BASEMENT ASSIGNMENT v SET ZACLBD 360 BSMT DOOR,LANTERN NORMAL V l V 1 PATENTL 31974 SHEET 10 01 18 FIGZOB SET MFX,SY SMF- CLEflECRA ASG CLEAR CRA,XW SET ZONE O NAC NAC+| SHOULD CAR CHANGED ZOQIE SET ZONE CODE SET ZACLBD PATENTELUEE 31914 31851.733

sum '12 0F 18 FIG. 20D

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ASGN MODE =00 f ASGN MID BLDG PARK AVADASGN 339 337 335 SET CAR N v SET CAR DTPK DNPK 34o F 342 343 I OUTPUT UPDATE UPDATE H W61 BTRA WORD INPUT DATA PATTNTT', IITI 3mm SHEET 1'3 BF Ia INITIALIZE FOR UP CALLS LDA WITH CALL WORD INITI ALIZE FOR DOWN CALLS FINISHED WITH IITH BIT OF?YCALL SET BIT IN XOR YCALL+ CLR WOR 8T STORE IN CCLR CLR YCALL YCALL O I CALLS ADDCALL To I TABLE ,S ZONE 6 TIMER NCL REMOVE CALL AND COMPACT TABLE DECR NCLTYNCLO REM VE BIT FROM CRA FOR EACH cAR WITH PROPER SASS FIG. 2|-

- PATENTE; UP! 31974 sum 15 er a FO CAR PTRS FOR XI UP CALL PROGRAM AHICAR-XI HIFLR-ACRFLR PATENTEL BEE 3W4 8 51.7 3 3 saw 170F18 600 605 F|G.23A

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Y CALL ASG REFLR-CALL FLR FIND CLOSESlQAR lS-AVAD-ASG EXPOSE CALL ADRESS MZ OUTPUT J v ASSIGNMENT PATENTELBEB 31914 3.851.733

sum mgr 1a FIG. 23B

DEMINDIMZ PROGRAM DEMIND BSMT DEMIND 2L0 DEMIND HI PROGRAM PROGRAM PROGRAM FIND EST CAR FOUND vI OUTPUT ASSGMNT SET DEMAS; MF RESET LOBMZD CROSS-REFERENCE TO RELATED APPLICATIONS Certain of the apparatus disclosed and described in this application, but not claimed, may be claimed in the following concurrently filed applications:

Application Ser.. No. 340,619, filed Mar. 12, 1973 in the name of .l. Vine, which is assigned to the same assignee as the present application.

Application Ser. No. 340,615, filed Mar. 12, 1973 in the name of N. Sackin, which is assigned to the same assignee as the present application.

BACKGROUND OF THE INVENTION 1. Field of the Invention:-

The invention relates in general to elevator systems and more specifically to elevator systems in which a plurality of elevator cars are controlled by a central dispatching control apparatus.

2. Description of the Prior Art:

ln the average multi-tenant building which includes an elevator system having a plurality of cars for serving the floors of the building, about 80 percent of the floor calls registered above the main floor are down calls, and even in a single-tenant building down calls predominate. Therefore, elevator systems which include a central dispatcher or system processor for controlling the dispatching of a plurality of elevator cars in response to floor calls, include special strategy for down calls.

For example, in one prior art system, the floors are divided into zones having one or more floors per zone, and a down floor call is assigned to all elevator cars having a position, service and travel direction which is suitable for the call location. The number of zones registering down calls are counted, and the number of elevator cars set for down travel which are in the process of serving down floor calls are also counted. When the number of zones having down calls exceeds the number of down runing cars serving the zones, a demand is created to which available or non-busy cars are assigned. When there are more down running cars than zones having down calls, the calls are deleted from the lowest of the cars and this car is made available. Any floor calls which it may have in its assignment register are givento the other cars. I

SUMMARY OF THE lNVENTlON Briefly, the present invention is a new and improved elevator system, and method of dispatching cars to serve floor calls for an elevator system, which provides new and improved strategy for allocating floor calls, and assigning cars to floor calls, including an improved arrangement and method for handling down calls.

A new floor call is allocated to the assignment register of at least one suitably conditioned car which is already in the process of serving calls. A suitably conditioned car is one which is located relative to the call, and with a travel and service direction such that it will be able to service the call in question as it continues its present course through the building. Failing to find such a car, a demand signal is created relative to the call and a non-busy car, i.e., a car which is in service but which is not presently in the process of serving a call for elevator service, is assigned to the demand call.

If there are no such cars available, the demand persists until a car becomes available, or a running car finally gets into a position which conditions it to serve the call.

The processed floor calls are reprocessed when an event occurs which indicates the possible need to reallocate oneor more of the floor calls. When a floor call is reprocessed, it is determined if there is a closer suitable car to the call floor than the car, or cars which presently have the call in their associated assignment registers. The cars are successively compared relative to a specific call and each time a closer suitable car is found than a previous suitable car, the call is deleted from the assignment register of a less suitable car. When all cars have been compared, the call is added to the assignment register of the closest suitable car found. Thus, after reprocessing, only one car has any one floor call in its assignment register.

When down floor car is allocated to a down running car, this car is not considered for further down calls. Thus, placing each call in the assignment register of only one car, and by allowing one down call to be allocated to a down running car, any excess calls over down running cars automatically creates a demand signal for an available car for each call in excess of the down running cars. It is not necessary to count the calls and to count the cars to implement this down availability strategy.

Further, the invention results in the call registers of the cars accurately representing the present traffic condition. The assignment registers of the cars are not cluttered with calls which they may not answer because another closer car with the same call will reach the call floor first. The invention thus returns the elevator cars to the available status much quicker, preventing unnecessary running through th building by cars which will not serve the call they are running for. The quicker return to the available status also reduces the waiting time required to assign available cars to demand calls.

The invention eliminates the prior art problem of deciding which car to remove from running status and to make available when the number of down running cars exceeds the number of down calls. In the prior art, arbitrarily deleting the calls from the assignment register of the lowest car and reallocating these calls to the remaining running cars may not always be the best strategy. With the present invention, the best strategy is always implemented, as the closest car to a call always has the call assignment.

In one embodiment of the invention, the removal of a floor call from the assignment register of a car which is not as close to the call floor as another car, is subject to the condition that the less suitable car has no registered car calls. 1f the less suitable car has one or more car calls, removing the floor call from its assignment register will not hasten its return to availability status, as the car will continue to be a busy car until it has served its car call. Thus, the floor call is not deleted from the assignment register of a car which has a car call, since it is a suitably conditioned car for the floor call, and the chance is present that the closer car may for some reason be delayed, allowing the less suitable car to answer the call. Thus, the less suitable car retains the floor call in its assignment register until the closer car answers the call, or the car call is served, or the less suitable car answers the floor call.

Claims

1. A method of allocating floor calls from a plurality of floors of a structure to a plurality of elevator cars mounted in the structure to serve the floors, comprising the steps of: providing means for registering floor calls from the plurality of floors of the structure, providing assignment means for each of the elevator cars, processing a new floor call by adding the call to the assignment means of at least one of the elevator cars or by creating a demand signal, reprocessing each floor call to locate the closest car in position to serve the call, deleting a floor call added to the assignment means of a car during the processing step when the reprocessing step finds a different car which is closer to the call floor, and adding the floor call to the assignment means of this closer car.

2. The method of claim 1, wherein the step of processing a new call includes the step of adding each new call to the assignment means of a suitable car whose advanced car position is closer to the call floor.

3. The method of claim 1 wherein the step of reprocessing each floor call includes the steps of providing signals relative to the advanced car position and service direction of each of the elevator cars, and considering these signals to determine if a car is suitable to answer the call.

4. The method of claim 1 including the step of providing a reallocation signal responsive to at least one event, the existence of which indicates the possible need for reallocating floor calls, with the reprocessing step being initiated in response to said reallocation signal.

5. The method of claim 1 including the step of dividing the structure into different zones for up and down calls and determining the zone of each car depending upon its position and service direction, and wherein the step of reprocessing each call includes a step of comparing the zone of a floor call and the zone of each car.

6. The method of claim 1 including the step of providing means in each elevator car for passengers to register car calls, and wherein the step of deleting a floor call from the assignment means of an elevator car when a closer suitable car is found is subject to the condition that the car has no registered car calls.

7. The method of claim 1 including the step of providing a signal when a down floor call is added to the assignment means of an elevator car, and considering this signal during the processing and reprocessing steps to remove this car from consideration for another down floor call.

8. The method of claim 1 wherein the processing and reprocessing steps consider those elevator cars which are not in the process of serving a call for elevator service as not suitable for allocation of calls, and including the step of assigning elevator cars in this category to floor calls for which a demand signal was created by the processing step.

9. An elevator system for a structure having a plurality of vertically spaced floors, comprising: a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure to serve the floors, down floor call registering means operable for registering a call for elevator service in the down direction from each of a plurality of said floors, up floor call registering means operable for registering a call for elevator service in the up direction from each of a plurality of said floors, car call registering means for each of The elevator cars operable for registering a call for each of a plurality of said floors which may be desired by load in the associated elevator car, dispatching means for allocating registered floor calls to selected elevator cars, and assignment register means associated with each of said elevator cars operable to receive floor call allocations of said dispatching means, said dispatching means including: collecting means for collecting floor calls from said up and down floor call registering means, processing means for periodically processing certain floor calls collected by said collecting means by either adding a selected floor call to the assignment register of at least one elevator car or registering a demand signal relative to the call, control means for detecting the possible need to reallocate at least certain of the floor calls to a different elevator car than the original allocation, and providing a signal when such need is detected, processing means processing only new floor calls unitl said control means provides a signal, at which time all of the floor calls in the system are processed, said processing means, when processing a floor call previously allocated to an elevator car, allocating the floor call to a second car in response to predetermined conditions, and deleting the floor call allocation from the assignment register of the first car in response to a predetermined condition.

10. The elevator system of claim 9 wherein the control means is responsive to predetermined conditions the occurrence of any one of which indicates a possible need to reallocate at least certain of the floor calls, with the control means being in a first condition, in the absence of all of the predetermined conditions and in a second condition when any one of the predetermined conditions occur, wherein the processing means is responsive to the control means to process all of the floor calls when the control means is in its second condition, and processing only new floor calls when the control means is in its first condition.

11. The elevator system of claim 10 wherein the predetermined conditions to which the control means is responsive includes an elevator car bypassing floor calls and an in-service elevator car going out of service.

12. The elevator system of claim 9 wherein the predetermined conditions to which the processing means will allocate a floor call previously allocated to a first car to a second car includes the second car being located relative to the call floor and with a service direction consistent with the service direction of the call, and with an advanced car position which is closer to the call floor than the advanced car position of the first car.

13. The elevator system of claim 9 wherein the predetermined condition which will cause the processing means to delete a call allocation from the assignment register means of a first car after allocating the floor call to a second car is the absence of a car call in the car call registering means of the first car.

14. The elevator system of claim 9 wherein the processing means includes means for excluding cars not in the process of serving a call for elevator service from consideration when allocating floor calls, and including means for assigning cars in this category to floor calls for which a demand signal was registered by the processing means, and wherein said processing means compares each car having an advanced car position and service direction suitable to answer a specific call with a previous car found suitable to determine which car has an advanced car position closer to the floor of the call, and uses the closer of the two for any subsequent comparison to obtain the closest suitable car to the call floor when all cars have been considered, with the processing means allocating the call to the assignment register means of the closest suitable car.

15. The elevator system of claim 9 including means for excluding an elevator car from consideration aS being suitable for a down floor call, when it already has another down floor call in its assignment register means.

16. A method of allocating floor calls from a plurality of floors of a structure to a plurality of elevator cars mounted in the structure to serve the floors, comprising the steps of: providing call table means to which new floor calls are added and answered floor calls are deleted, periodically ordering all of the floor calls in the call table means such that floor calls appear in the call table in the order in which their associated floors are located in the structure, adding calls received between ordering steps to an end of the ordered floor calls, providing an assignment register for each of the elevator cars, periodically processing the new calls located at the end of the ordered floor calls in the call table means by adding each new call to the assignment register of at least one of the elevator cars, or by creating a demand signal, processing all of the calls in the call table means following each ordering step by successively determining the suitability of at least certain of the elevator cars relative to serving each floor call, starting with the call located at one end of the call table, determining the suitable car, if any, whose advanced car position is closest to each floor call by comparing the advanced car position of each car found to be suitable for a specific floor call with the advanced car position of a previous car found to be suitable for this call and using only the closer of the two cars for comparison with the advanced car position of a subsequent car found to be suitable for this call, deleting a floor call allocation, if any, from the assignment register of a suitable car when a closer suitable car is found for this floor call, allocating each floor call to the closest suitable car found by entering the floor call in the assignment register of the selected car, and creating a demand signal when a suitable car cannot be found for a floor call.

17. The method of claim 16 wherein the step of periodically processing the new calls located at the end of ordered calls in the call table means includes the step of allocating each new call to a suitable car whose advanced car position is closest to the call.

18. The method of claim 16 wherein the step of successively considering the suitability of each car relative to serving each call includes the steps of providing signals relative to the advanced car position and service direction of each of the elevator cars, and considering these signals to determine if the car is conditioned to answer the call.

19. The method of claim 16 including the step of providing a reordering signal responsive to at least one event, the existence of which indicates the possible need for reallocating floor calls, wherein the presence or absence of the reordering signal is used to initiate the step of periodic ordering of the floor calls in the call table, and the step of periodic processing of only the new calls, respectively.

20. The method of claim 16 including the step of dividing the structure into different zones for up calls and different zones for down calls, and determining the zone of each car depending upon its position and service direction, and wherein the step of successively considering the suitability of each car relative to serving each call includes the step of comparing the zone of the floor call and the zone of each car.

21. The method of claim 16 including the step of providing means in each elevator car for passengers to register car calls, and wherein the step of deleting a floor call allocation from the assignment register of an elevator car when a closer suitable car is found is subject to the condition that the car has no registered car calls.

22. The method of claim 16 including the step of providing a signal when a down floor call is allocated to the assignment resister of an elevator car, which signal is considereD during the step of considering the suitability of the car for another down floor call, removing this car from consideration for such a call.

23. The method of claim 16 wherein the step of successively considering at least certain of the elevator cars relative to serving each call in the ordered call table considers those elevator cars which are not in the process of serving a call for elevator service as not suitable for allocation of calls, and including the step of assigning elevator cars in this category to floor calls for which a demand signal was created by the processing step.

24. An elevator system for a structure having a plurality of vertically spaced floors, comprising: a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure to serve the floors, down floor call registering means operable for registering a call for elevator service in the down direction from each of a plurality of said floors, up floor call registering means operable for registering a call for elevator service in the up direction from each of a plurality of said floors, car call registering means for each of the elevator cars operable for registering a call for each of a plurality of said floors which may be desired by load in the associated elevator car, dispatching means for allocating registered floor calls to selected elevator cars, and assignment register means associated with each of said elevator cars operable to receive floor call allocations from said dispatching means, said dispatching means including: first means for collecting floor calls from said up and down floor call registering means, second means for periodically ordering the floor calls collected by said first means such that their locations relative to one another correspond to the locations of their associated floors in the structure, said first means adding floor calls collected subsequent to the ordering of the floor calls by said second means to an end of the ordered floor calls, and third means for periodically processing certain floor calls collected by said first means by either allocating a selected floor call to the assignment register of at least one elevator car or registering a demand signal relative to the call, said third means being responsive to said second means, processing all of the floor calls each time said second means orders the floor calls and otherwise only processing floor calls added to an end of the ordered floor calls, said third means, when processing a floor call previously allocated to an elevator car, allocating the floor call to a second car in response to predetermined conditions and deleting this floor call allocation from the assignment register of the first car in response to a predetermined condition.

25. The elevator system of claim 24 including control means responsive to predetermined conditions the occurrence of any one of which indicates a possible need to reallocate at least certain of the floor calls, said control means being in a first condition in the absence of all of said predetermined conditions and in a second condition when any one of said predetermined conditions occur, wherein the dispatching means is responsive to said control means, with its second means being effective when said control means is in its second condition to order all of the floor calls, and cause its third means to process all of the floor calls, and with the third means processing only the calls at the end of the ordered floor calls when the control means is in its first condition.

26. The elevator system of claim 25 wherein the predetermined conditions to which the control means is responsive includes an elevator car bypassing floor calls and an in-service elevator car going out of service.

27. The elevator system of claim 24 wherein the predetermined conditions to which the third means will allocate a floor call previously allocated to a first car to a second car include the secoNd car being located relative to the call floor and with a service direction consistent with the service direction of the call, and with an advanced car position which is closer to the call floor than the advanced car position of the first car.

28. The elevator system of claim 24 wherein a predetermined condition which will cause the third means to delete a call allocation from the assignment register means of a first car after allocating the floor call to a second car is the absence of a car call on the car call registering means of the first car.

29. The elevator system of claim 24 wherein the third means includes means for excluding cars not in the process of serving a call for elevator service from consideration when allocating floor calls, and including means for assigning cars in this category to floor calls for which a demand signal was registered by the third means, and wherein said third means successively compares each car having an advanced car position and service direction suitable to answer a specific call with a previous car found suitable to determine which car has an advanced car position closer to the floor of the call, and uses the closer of the two for any subsequent comparison, to obtain the closest suitable car to the call floor when all cars have been considered, with said third means allocating the call to the assignment register means of the closer suitable car.

30. The elevator system of claim 24 including means for excluding an elevator car from consideration as being suitable for allocating a down floor call when it already has a down floor call in its assignment register means.