Group control overload protection for elevators with immediate allocation of calls of destination

• US 4,939,634 A
• Filed: 07/27/1988
• Issued: 07/03/1990
• Est. Priority Date: 07/28/1987
• Status: Expired due to Term

• Current Assignee: Inventio AG (Schindler Holding AG)
• Original Assignee: Inventio AG (Schindler Holding AG)
• Inventors: Schroder, Joris
• Primary Examiner(s): Smith, Jerry
• Assistant Examiner(s): Trammell, James P.
• Application Number:
  US07/224,760
• Time in Patent Office: 706 Days
• Field of Search: 187/121, 187/124, 187/127, 187/130, 187/131, 187/133, 364/141
• US Class Current: 700/12
• CPC Class Codes: B66B 1/2458 For elevator systems with multiple shafts and a single car per shaft
• CPC Class Codes: B66B 2201/103 Destination call input before entering the elevator car
• CPC Class Codes: B66B 2201/211 Waiting time, i.e. response time
• CPC Class Codes: B66B 2201/222 Taking into account the number of passengers present in the elevator car to be allocated
• CPC Class Codes: B66B 2201/232 where the time needed for a passenger to arrive at the allocated elevator car from where the call is made is taken into account

Abstract

A group control for an elevator system, in which it is possible to assign a newly entered floor call to a car for the first time, immediately and finally, includes a computer and a comparator circuit for calculating operating costs and assigning the call to the car with the lowest cost during a comparison cycle. The operating cost includes car load values for the floors which are stored in a load table for the assigned car. Upon the assignment of a floor call, the load value for the call input floor is increased proportionally to the number of entered calls and the load values at the floors of destination are reduced proportionally to the number of calls for the respective floor of destination. These load values are used by a monitoring circuit to prevent the assignment of a call which would cause an overload condition.

Claims

1. An improvement in a group control for elevators having at least two elevator cars for serving a plurality of floors and for the immediate assignment of floor calls of destination, the group control including ten key keyboard call registering devices arranged at the floors for entering floor calls for desired floors of destination, floor call and car call memories assigned to the cars of the group and connected with the call registering devices where on input of floor calls at a floor, an entry floor call representing the input floor is stored in the floor call memory and destination floor calls representing the floors of destination are stored in the car call memory, load measuring devices provided in the cars, selectors assigned to each car indicating in each case the floor of a possible stop, first and second scanners assigned to each car and having for every floor at least one position, and for each car a computer and a comparison device wherein the computer calculates at each floor designated by the first scanner from at least the distance between the floor and a floor indicated by the selector, the intermediate stops to be expected within this distance, and the load in the car the operating costs corresponding to the waiting times of the passengers, and wherein the operating costs of all cars at every position of the second scanner are compared with each other by the comparison device and the respective cell is assigned to that car which exhibits the smallest operating costs, the improvement comprising:

a load table for storing load values corresponding to the loads in the car and which is connected with the computer and the car call memory and upon input of a floor call at an entering floor and the storage of associated destination floor calls in the car call memory, the load values at the entering floor are increased proportionally to the number of the entered calls and the load values at the floors of destination are reduced proportionally to the number of calls for the respective floor of destination and the computer utilizes the load values stored in the load table in the calculation of the operating costs and includes a cost memory for storing the calculated operating costs; and

a monitoring circuit connected with said load table and responsive to the existence of a load value exceeding a given load limit value for preventing an assignment to the respective car of a call causing an overload, said monitoring circuit including a comparator, a first register containing a load limit value (L_max), a second register containing a maximum value of the operating costs (K_max), first and second tristate buffers and a NOT-gate, inputs of the comparator are connected to outputs of said load table and said first register and an output is connected to a control input of said first tristate buffer and through said NOT-gate with a control input of said second tristate buffer, and said second register is connected through said first tristate buffer with data inputs of the comparison device are also connected through said second tristate buffer to a data bus of the computer and at every position of the second scanner said monitoring circuit is activated and in case of an overload at a floor, the maximum value of the operating costs (K_max) contained in the second register is generated to the comparison device instead of the operating costs stored in said cost memory.

2. The improvement according to claim 1 wherein said load table includes a write-read memory in the form of a matrix having as many lines as floors and three columns defining a plurality of storage locations.

3. The improvement according to claim 2 wherein said three columns include a first column for calls in the direction of travel and lying ahead of the car, a second column for calls in an opposite direction of travel, and a third column for calls in the direction of travel and lying behind the car.

4. The improvement according claim 1 wherein said load values stored in said load table represent numbers of passengers.

5. The improvement according to claim 1 wherein said load table is connected with the load measuring device of the car and at differences between the stored load values and measured loads, the stored load values are matched to the measured loads and for positive differences a corresponding number of calls to the same floors of destination are cleared.

6. A group control for elevators having at least two cars for serving a plurality of floors and for the immediate assignment of floor calls of destination, comprising:

call registering devices at each floor for entering floor calls for desired floors of destination;

a floor call memory for each car for storing a floor call for a floor of entry;

a car call memory for each car for storing destination floor calls from said floor of entry;

a load measuring device associated with each car for indicating the number of passengers;

a selector for each car for indicating the floor at which the car can stop;

first and second scanners for each car having a position for each floor;

a computer for each car connected to said call registering devices and to the computers for the other cars and connected to said floor call memory, said car call memory, said load measuring device, said selector, and said first and second scanners for an associated car and responsive to said first scanner for calculating for each floor the operating costs corresponding to the waiting times of any passengers;

a comparison device for each car connected to said computer associated with the car for comparing the operating costs of all the cars at every floor designated by said second scanner to assign the floor call to the car with the smallest operating costs;

a load table for each car connected to said computer associated with the car for storing load values representing the number of passengers in the car and responsive to the input of floor calls and the storage of said destination floor calls in said car call memory for increasing the load value for the floor of entry proportionally to the number of entered destination floor calls and for decreasing the load values at the floors of destination proportionally to the number of calls for the respective floor, said computer utilizing said load values in calculating said operating costs; and

a monitoring circuit for each car connected to said comparison device and to said load table for the associated car and responsive to one of said load values exceeding a predetermined load limit value for preventing the assignment of the floor call to the associated car, said monitoring circuit including a first register for storing a load limit maximum value, a second register for storing an operating costs maximum value, a comparator having inputs connected to an output of said load table and to an output of said first register and an output connected through a Not-gate to a control input of a first tristate buffer and to a control input of a second tristate buffer, said first tristate buffer having an input connected to said computer and an output connected to said comparison device, and said second tristate buffer having an input connected to an output of said second register and an output connected to said comparison device.

7. The group control according to claim 6, wherein said load table is a write-read memory formed as a matrix of storage locations having three storage locations for each floor served by the cars.

8. The group control according to claim 7 wherein said three storage locations include a first location for calls in the direction of travel and ahead of the associated car, a second location for calls in the opposite direction of travel, and a third location in the direction of travel and behind the associated car.