Method for controlling an elevator system

Abstract

A method for controlling an elevator where an elevator is allocated for the use of a passenger in a first optimization phase in such a way that a first cost function is minimized, a second optimization phase is performed, in which the route of the allocated elevator is optimized in such a way that a second cost function is minimized.

Claims

1. A method for controlling an elevator system, which elevator system comprises: at least one elevator; call-giving devices for giving calls to the elevator system; and a control system that is responsive to the calls, wherein the method comprises the steps of: registering a call given by a passenger; allocating an elevator serving the registered call in a first optimization phase in such a way that a desired first cost function is minimized; optimizing the route of the allocated elevator in a second optimization phase in such a way that a desired second cost function is minimized; and controlling the allocated elevator according to the optimized route.

2. The method according to claim 1, further comprising the step of updating the optimized route of an elevator by repeating the second optimization phase during the elevator service.

3. The method according to claim 1, further comprising the step of utilizing genetic algorithms in the first and/or in the second optimization phase.

4. The method according to claim 1, further comprising the step of using the collective control principle in the first optimization phase.

5. The method according to claim 1, wherein the first cost function and/or the second cost function comprises at least one magnitude related to the operation of the elevator system, which magnitudes are: call time, waiting time, travel time, run time, traffic intensity, and energy consumption.

6. The method according to claim 1, wherein the first cost function and/or the second cost function is minimized for at least one desired magnitude with a set boundary condition.

7. The method according to claim 1, wherein the method further comprises the phase: further comprising the step of making an assumption about the destination floor of a passenger if the call is given with up/down call pushbuttons.

8. The method according to claim 2, further comprising the step of utilizing genetic algorithms in the first and/or in the second optimization phase.

9. The method according to claim 2, further comprising the step of using the collective control principle in the first optimization phase.

10. The method according to claim 3, further comprising the step of using the collective control principle in the first optimization phase.

11. The method according to claim 2, wherein the first cost function and/or the second cost function comprises at least one magnitude related to the operation of the elevator system, which magnitudes are: call time, waiting time, travel time, run time, and traffic intensity, energy consumption.

12. The method according to claim 3, wherein the first cost function and/or the second cost function comprises at least one magnitude related to the operation of the elevator system, which magnitudes are: call time, waiting time, travel time, run time, and traffic intensity, energy consumption.

13. The method according to claim 4, wherein the first cost function and/or the second cost function comprises at least one magnitude related to the operation of the elevator system, which magnitudes are: call time, waiting time, travel time, run time, and traffic intensity, energy consumption.

14. The method according to claim 2, wherein the first cost function and/or the second cost function is minimized for at least one desired magnitude with a set boundary condition.

15. The method according to claim 3, wherein the first cost function and/or the second cost function is minimized for at least one desired magnitude with a set boundary condition.

16. The method according to claim 4, wherein the first cost function and/or the second cost function is minimized for at least one desired magnitude with a set boundary condition.

17. The method according to claim 5, wherein the first cost function and/or the second cost function is minimized for at least one desired magnitude with a set boundary condition.

18. The method according to claim 2, further comprising the step of making an assumption about the destination floor of a passenger if the call is given with up/down call pushbuttons.

19. The method according to claim 3, further comprising the step of making an assumption about the destination floor of a passenger if the call is given with up/down call pushbuttons.

20. The method according to claim 4, further comprising the step of making an assumption about the destination floor of a passenger if the call is given with up/down call pushbuttons.

Description

LIST OF FIGURES

(1) FIG. 1a presents the routing, produced by the method according to the invention, for an elevator in one embodiment,

(2) FIG. 1b presents the routing, produced by collective control, for an elevator in the embodiment according to FIG. 1a,

(3) FIG. 2a presents the routing, produced by the method according to the invention, for an elevator in a second embodiment,

(4) FIG. 2b presents the routing, produced by collective control, for an elevator in the embodiment according to FIG. 2a, and

(5) FIG. 3 presents a method for optimizing an elevator system.

DETAILED DESCRIPTION OF THE INVENTION

(6) In the following the invention will be described in the light of some embodiments.

(7) Embodiment 1. The elevator system of a building comprises one elevator E1, which is at floor F1. Three passengers have given to the elevator system destination calls r1, r2 and r3 according to Table 1:

(8) TABLE-US-00001 TABLE 1 Call Departure floor Destination floor r1 2 1 r2 15 1 r3 40 1

(9) The following table presents the parameters connected to the elevator E1.

(10) TABLE-US-00002 TABLE 2 Parameter Value Rated speed of elevator car 4 m/s Acceleration of elevator car 1 m/s**2 Jerk 1.6 m/**3 Capacity 13 persons Door opening time 3 s Door closing time 3.1 s Person transfers (in, out) 2 s

(11) The following table presents the parameters connected to the building.

(12) TABLE-US-00003 TABLE 3 Parameter Value Number of floors 40 floors Floor-to-floor height 3.3 m

(13) Table 4 presents the waiting times and travel times connected to the optimal routing calculated according to the invention.

(14) TABLE-US-00004 TABLE 4 Magnitude r1 r2 r3 Average Waiting time (s) 10.41 45.10 112.27 55.93 Travel time (s) 21.82 68.37 156.17 88.12

(15) Table 5 presents the waiting times and travel times achievable with routing based on conventional collective control.

(16) TABLE-US-00005 TABLE 5 Magnitude r1 r2 r3 Average Waiting time (s) 97.70 75.25 42.90 71.95 Travel time (s) 109.11 110.11 111.11 110.11

(17) FIG. 1a presents a route according to Embodiment 1, which route is optimized with the method according to the invention, for an elevator E1.

(18) FIG. 1b presents a route according to Embodiment 1, which route is based on collective control.

(19) Embodiment 2: In this embodiment the energy consumption is examined instead of waiting times and travel times. In the same way as Embodiment 1, in this embodiment the elevator system of the building comprises one elevator E1 and three passengers have given destination calls r1, r2 and r3 according to Table 6.

(20) TABLE-US-00006 TABLE 6 Call Departure floor Destination floor r1 1 11 r2 3 2 r3 11 10

(21) The following table 7 presents the parameters connected to the elevator E1.

(22) TABLE-US-00007 TABLE 7 Parameter Value Rated speed of elevator car 4 m/s Acceleration of elevator car 1 m/s**2 Jerk 1.6 m/**3 Capacity 1800 kg

(23) When the route of the elevator is optimized with the method according to the invention, an energy consumption of 102 Wh is obtained and correspondingly 293 Wh with routing based on conventional collective control, the difference being 187%. (In the calculation the values of Table 3 have been used as the parameters of the building).

(24) FIG. 2a presents an optimized route of the elevator E1 according to Embodiment 2, and FIG. 2b a route based on the collective control according to Embodiment 2.

(25) FIG. 3 presents a method for controlling an elevator system, including registering a call given by a passenger via a call-giving device having up/down pushbuttons, allocating an elevator serving the registered call in a first optimization phase utilizing a genetic or collective control principle to minimize a desired first cost function, optimizing the route of the allocated elevator in a second optimization phase, controlling the allocated elevator according to the optimized route utilizing a genetic algorithm to minimize a desired second cost function and updating the optimized route by repeating the second optimization phase.

(26) The method according to the invention is also applicable to elevator systems in which up/down call-giving pushbuttons are used for calling an elevator to a floor. According to one embodiment of the invention the control system makes an assumption about the destination floor e.g. in such a way that when pressing the up call pushbutton the topmost floor that the elevator system serves is used as the default floor. Correspondingly, when pressing the down call button, the bottommost floor that the elevator system serves is used as the default floor. It is also possible to collect statistical data about the elevator journeys made by passengers and to use the data in question to advantage in the definition of the default floor.

(27) In both the first optimization phase and the second optimization phase genetic algorithms can be utilized. When a new call has been allocated to an elevator, and the optimal route calculated in the manner described above, the route can be updated by repeatedly performing a second optimization phase during the elevator service. A limit value, which may not be overshot/undershot in the optimization, can be set for the desired magnitude or cost term in the cost function of the first and/or second optimization phase. With this it can be ensured that e.g. the waiting times of passengers do not exceed the set limit value. In the first optimization phase preferably the collective control principle is used, with the cost terms being call times, waiting times, travel times, run times and/or energy consumptions. In the second optimization phase the route of the elevator is optimized by minimizing some certain cost term, e.g. the energy consumption of the elevator for serving the calls. Since the route of the elevator has not necessarily after this been implemented as a route according to collective control, this can cause in elevator passengers doubtfulness and uncertainty about the routes used by the elevators. To avoid this, the elevator lobbies and/or elevator cars can be provided with information means for informing elevator passengers of the routes used by the elevators.

(28) The invention is not only limited to be applied to the embodiments described above, but instead many variations are possible within the scope of the inventive concept defined by the claims. Thus, for example, route optimization can be performed for one or more elevators before or after the making of the final allocation decision.