ELEVATOR
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001]
The present invention relates to an elevator of the type moving an elevator car in a standby mode to a predetermined floor where the car parks.
2. Description of the Related Art
[0002]
Conventional elevators are classified into elevators of the type leaving an elevator car in the last service floor when there is no call and elevators of the type moving an elevator car to a predetermined floor where the car parks, and changing the mode of the car to a standby mode when there is no call. For example, there are known an elevator of the type comparing the number of ascending hall calls with the number of descending hall calls which have occurred a predetermined time ago from the time when there is no elevator call, and keeping an elevator car on standby at a predetermined lower floor where the car parks when the number of ascending hall calls is larger than the number of descending hall calls but keeping the elevator car on standby at a predetermined upper floor where the car parks when the number of descending hall calls is larger than the number of ascending hall calls to thereby shorten users' waiting time to attain improvement in service (e.g. see JP-A-4-179681), an elevator of the type storing the number of registered hall calls per unit time in each floor in accordance with each day of the week and each time zone and keeping an elevator car on standby at a floor where the number of registered hall calls is highest in each time zone based on at least one of the past data and the current data (e.g. see
1

JP-A-57-121569), and an elevator of the type storing the state of hall call occurrence in each hall in accordance with each month, each time zone, each day of the week, etc., forecasting demand for each floor based on these learning data, finding a floor in the greatest demand, and keeping an elevator car on standby at that floor (e.g. see JP-A-60-209475).
[0003]
In a conventional elevator, there is a description that an elevator car is moved at a low speed in accordance with a wind speed when operation control to move back the elevator car to a reference floor is performed in order to avoid danger caused by a gale in a high-rise building (e.g. see JP-UM-A-62-121259). There are further known a description that delicate control to allocate an elevator car in a standby mode to a floor high in the rate of call occurrence in advance is performed so that a floor short in the travel distance is selected to be effective in energy saving when there are floors high in the rate of call occurrence (e.g. see JP-A-10-36019) and a description that an energy saving target value is determined and compared with an actual electric power consumption value to thereby adjust a speed control constant of an elevator car so that the actual electric power consumption value does not exceed the target value (e.g. see JP-A-2007-55700).
[0005]
In the conventional elevators inclusive of JP-A-4-179681, JP-A-57-121569 and JP-A-60-209475, a state in which the frequency in use of the car is lowered because of no car call at least for a predetermined time is detected as a standby state, but an energy saving effect in this state is however unconsidered sufficiently. Therefore, how to move the elevator car to a floor where the car parks while achieving such an energy saving effect after determination of the floor where the car parks has
2

not been discussed.
SUMMARY OF THE INVENTION
[0006]
An object of the invention is to provide an elevator in which suppression of peak electric power or reduction of electric power consumption at the time of moving an elevator car to a floor where the car parks can be attained without spoiling user-friendliness.
[0007]
To achieve the foregoing object, according to the invention, there is provided an elevator including: an elevator controller which controls up/down movement of an elevator car; a standby mode elevator car determination unit which determines an elevator car in a standby mode when the elevator car is not in a floor where the car parks and there is neither hall call registration nor car call registration; a parking floor determination unit which determines a floor where the elevator car in the standby mode parks when determination is made that the elevator car is in the standby mode; and a car speed/acceleration determination unit which determines a car speed and a car acceleration for moving the elevator car in the standby mode to the floor where the car parks; wherein: the car speed/acceleration determination unit is provided so that at least one of the car speed and the car acceleration for moving the elevator car in the standby mode to the floor where the car parks becomes lower than that at the time of normal operation.
[0008]
According to the aforementioned configuration, the state of low use is detected as a standby state and at the same time at least one of the car speed and the car acceleration for moving the elevator car to a floor where the car parks is made lower
3

than that at the time of normal operation. Accordingly, it is possible to achieve an elevator in which suppression of peak power or reduction of power consumption at the time of moving the elevator car to the floor where the car parks can be attained by setting of car speed or car acceleration without spoiling user-friendliness.
[0009]
In addition to the aforementioned configuration, in the invention, the parking floor determination unit determines a floor high in the frequency of hall call occurrence in substantially the same time zone as the floor where the car parks, based on past hall call occurrence frequency history.
[0010]
According to the aforementioned configuration, a floor high in the frequency of hall call occurrence in substantially the same time zone is determined as the floor where the car parks, based on the past hall call occurrence frequency history. Accordingly, the elevator car can be allocated so that users in a floor statistically high in the probability of average hall call occurrence are not kept waiting. At least one of the car speed and the car acceleration on this occasion can be made lower than that at the time of normal operation and at the same time the energy saving effect can be improved.
[0011]
In addition to the aforementioned configuration, in the invention, the parking floor determination unit determines a floor high in the frequency of hall call occurrence in substantially the same time zone as the floor where the car parks, based on the past hall call occurrence frequency history; and the car speed/acceleration determination unit divides the hall call occurrence frequency into zones so that at least one of the car speed and the car acceleration for arrival of the car at the floor where the
4

car parks becomes lower as the hall call occurrence frequency in the zones becomes lower.
[0012]
According to the aforementioned configuration, the elevator car in the standby mode can be moved to the floor where the car parks, at the car speed and the car acceleration according to the utilization form peculiar to the building in which the elevator is disposed. Moreover, the frequency of hall call occurrence can be divided into a plurality of zones so that at least one of the car speed and the car acceleration can be adjusted in accordance with each zone. Accordingly, service can be performed immediately in response to a hall call at a floor high in the frequency of hall calls.
[0013]
In addition to the aforementioned configuration, according to the invention, there is provided an elevator further including: an expected time calculation unit which calculates expected time of next hall call occurrence after determination is made that the elevator car is in a standby mode; wherein: the car speed/acceleration determination unit selects at least one of the car speed and the car acceleration for arrival of the car at the floor where the car parks, in the expected time.
[0014]
According to the aforementioned configuration, expected time of next hall call occurrence in the elevator car in the standby mode can be calculated and either or both of the car speed and the car acceleration can be set so that the elevator car in the standby mode will arrive at the floor where the car parks, in the expected time of the hall call occurrence. Accordingly, the car speed and the car acceleration of the elevator car in the standby mode can be set to be reduced in accordance with the calculated expected time of the hall call occurrence, that is, because the time up to
5

arrival of the car at the floor where the car parks becomes long as the expected time of the hall call occurrence becomes long. Consequently, the energy saving effect can be improved.
[0015]
In addition to the aforementioned configuration, according to the invention, there is provided an elevator further including: an expected time calculation unit which calculates expected time of next hall call occurrence after determination is made that the elevator car is in a standby mode; wherein: the car speed/acceleration determination unit divides the expected time into zones so that at least one of the car speed and the car acceleration for arrival of the car at the floor where the car parks becomes lower as the expected time in the zones becomes longer.
[0016]
According to the aforementioned configuration, the car speed and the car acceleration are not simply reduced but can be set in accordance with each zone of the expected time of hall call occurrence so that the elevator car in the standby mode will arrive at the floor where the car parks, in the expected time of hall call occurrence. For example, because the time up to arrival of the car at the floor where the car parks becomes long as the expected time of hall call occurrence becomes long, the speed and the acceleration of the elevator car in the standby mode can be set to be reduced so that the energy saving effect can be improved more greatly.
[0017]
In addition to the aforementioned configuration, according to the invention, there is provided an elevator further including: an expected time calculation unit which calculates expected time of next hall call occurrence after determination is made that the elevator car is in a standby mode; and a distance calculation unit which calculates a
6

travel distance between the position of the elevator car in the standby mode determined by the standby mode elevator car determination unit and the floor where the car parks; wherein: a plurality of zones are provided in accordance with the rate of the travel distance to the expected time so that the car speed/acceleration determination unit selects at least one of the car speed and the car acceleration for moving the elevator car in the standby mode to the floor where the car parks, in accordance with the zones.
[0018]
According to the aforementioned configuration, the car speed and the car acceleration can be set more accurately in accordance with the expected time of hall call occurrence so that the elevator car in the standby mode will arrive at the floor where the car parks. As a result, service can be performed without spoiling user-friendliness, that is, without increase in waiting time.
[0019]
In addition to the aforementioned configuration, according to the invention, there is provided an elevator further including: an expected time calculation unit which calculates expected time TA of next hall call occurrence after determination is made that the elevator car is in a standby mode; and a distance calculation unit which calculates a travel distance XA between the position of the elevator car in the standby mode determined by the standby mode elevator car determination unit and the floor where the car parks; wherein: a plurality of zones are provided in accordance with the rate XA/TA, and the car speed/acceleration determination unit determines the car speed/ acceleration so that at least one of the car speed and the car acceleration for moving the elevator car in the standby mode to the floor where the car parks becomes lower as the rate XA/TA becomes smaller.
[0020]
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According to the aforementioned configuration, the car speed index (XA/TA) can be used so that the elevator car in the standby mode will arrive at the floor where the car parks, surely in the expected time TA of next hall call occurrence. Moreover, the speed and the acceleration of the elevator car in the standby mode can be extracted in accordance with each car speed index (XA/TA) zone, so that the car speed and the car acceleration can be set more appropriately.
[0021]
In addition to the aforementioned configuration, according to the invention, there is provided an elevator further including: a time zone detection unit provided with a plurality of time zones; wherein: the time when the elevator car in the standby mode is determined by the standby mode elevator car determination unit is made to correspond to one of the time zones in the time zone detection unit so that the car speed/acceleration determination unit selects at least one group of car speeds and car accelerations set in accordance with the time zones.
[0022]
According to the aforementioned configuration, the car speed and the car acceleration can be set so that priority is given to reduction of maximum speed in a time zone in which greater importance is given to power peak suppression, but the car speed and the car acceleration can be set so that priority is given to reduction of car acceleration in the other time zone in order to give greater importance to power saving. The car speed or the car acceleration can be controlled desirably in accordance with each time zone without spoiling elevator user-friendliness.
[0023]
In the elevator according to the invention, the state of low use is detected as a standby state and at the same time at least one of car speed and car acceleration for
8

moving an elevator car in a standby mode to a floor where the car parks is made lower than that at the time of normal operation. Accordingly, it is possible to achieve an elevator in which suppression of peak power or reduction of power consumption at the time of movement of the car to the floor where the car parks can be attained in sufficient consideration of the energy saving effect in the standby state without spoiling user-friendliness.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024]
Fig. 1 is a schematic configuration diagram showing an elevator according to an embodiment of the invention;
Fig. 2 is an enlarged block configuration diagram of important part of the elevator shown in Fig. 1;
Fig. 3 is an explanatory view schematically showing an average hall call occurrence rate database in hall call history data shown in Fig. 1;
Fig. 4 is an explanatory view schematically showing an average hall call occurrence time interval database in the hall call history data shown in Fig. 1;
Fig. 5 is an explanatory view schematically showing a car speed/acceleration setting table stored in the car speed/acceleration data shown in Fig. 1;
Fig. 6 is a car speed characteristic graph of a power peak suppression management time zone shown in Fig. 5;
Fig. 7 is a car acceleration characteristic graph of the power peak suppression management time zone shown in Fig. 5;
Fig. 8 is a car speed characteristic graph of a power saving management time zone shown in Fig. 5;
Fig. 9 is a car acceleration characteristic graph of the power saving
9

management time zone shown in Fig. 5;
Fig. 10 is a characteristic graph showing a pattern of comparison between car speed and car acceleration at the time of normal operation;
Fig. 11 is a characteristic graph showing a pattern of comparison between car speed and car acceleration when greater importance is given to power peak suppression;
Fig. 12 is a characteristic graph showing a pattern of comparison between car speed and car acceleration when greater importance is given to power saving;
Fig. 13 is an operation characteristic graph at the time of movement of an elevator car to a floor where the elevator car in a standby mode parks;
Fig. 14 is a block configuration diagram showing important part of an elevator according to an embodiment of the invention; and
Fig. 15 is an explanatory view schematically showing a car speed/acceleration setting table stored in the car speed/acceleration data shown in Fig. 14. DETAILED DESCRIPTION OF THE INVENTION
[0025]
An embodiment of the invention will be described below with reference to the drawings.
[0026]
Fig. 1 is an overall configuration diagram showing an elevator which is formed so that a sheave 5 connected to a motor 4 and wound with a main rope 3 for connecting an elevator car 1 and a balance weight 2 to each other is rotated to move up and down the elevator car 1. Rotation control of the motor 4 is executed by a power converter 6 which is controlled by an elevator controller 7. The elevator controller 7 includes a main control portion 8 which takes charge of main control of the elevator, a
10

data storage portion 9 which stores various elevator-relevant data inputted or calculated in the main control portion 8, and a standby mode elevator car control portion 10 which operates the elevator car in a standby mode to a floor where the car parks.
[0027]
For example, the main control portion 8 takes in hall call data 12, car call data 14, in-car load data 16, floor-based pedestrian flow detection data 18 and motor rotation quantity detection data 20 and executes operation control of the elevator car 1 in accordance with registration of hall calls and car calls. The hall call data 12 are registered by operation of hall call registration devices 11A to 11D disposed in halls in respective floors. The car call data 14 is registered by operation of a car call registration device 13 disposed in the elevator car 1. The in-car load data 16 is detected by a load sensor 15 disposed in the elevator car 1. The floor-based pedestrian flow detection data 18 are detected in accordance with respective floors by pedestrian flow sensors 17Ato 17D such as image sensors, infrared sensors, photoelectronic sensors, etc. which detect motion of pedestrians in the respective floors. The motor rotation quantity detection data 20 is obtained from an encoder 19 which detects the rotation quantity of the motor 4.
[0028]
As shown in Fig. 2 which is an enlarged view of important part, the data storage portion 9 stores hall call history data 21, car call history data 22, pedestrian flow situation history data 23, current car state data 24, a parking floor setting table 25, average hall call occurrence rate data 26, average hall call occurrence time interval data 27, a car speed/acceleration table 28, etc. The hall call history data 21 are accumulated as data obtained in such a manner that information of occurrence time, occurrence floor, moving direction, etc. is added to the hall call data 12 given from the
11

hall call registration devices 11A to 1 ID. The car call history data 22 is accumulated as data obtained in such a manner that information of occurrence time, etc. is added to the car call data 14 given from the car call registration device 13. The pedestrian flow situation history data 23 are accumulated based on the pedestrian flow detection data 18 given from the pedestrian flow sensors 17A to 17D in respective floors. The current car state data 24 is accumulated in such a manner that the current state of the elevator car such as the current position, speed, moving direction, etc. of the elevator car 1 is collected. The parking floor setting table 25 is set when a floor where the elevator car in a standby mode parks is designated in advance. The average hall call occurrence rate data 26 is data obtained in such a manner that the average hall call occurrence probability in the moving direction and each floor is stored as a database in accordance with a plurality of time zones by use of the hall call history data 21. The average hall call occurrence time interval data 27 is data obtained in such a manner that the average hall call occurrence time in the moving direction and each floor is stored as a database in accordance with a plurality of time zones by use of the hall call history data 21. The car speed/acceleration table 28 is formed in such a manner that expected time TA of next hall call occurrence is divided into a plurality of time zones by use of the average hall call occurrence time interval data 27, and car speed and car acceleration in the case where the elevator car 1 in a standby mode is moved to a floor where the car parks are set in accordance with the plurality of time zones.
[0029]
These data are stored in the data storage portion 9 when detected by the main control portion 8 or are set in the data storage portion 9 based on initial inputting operation. Although the case where there is one elevator car 1 is shown here, a collectively managed elevator group may be intended for a plurality of elevator cars.
12

When the elevator group is intended for a plurality of elevator cars, the following control is applied to each elevator car.
[0030]
The standby mode elevator car control portion 10 has a standby mode elevator car determination unit 29, a parking floor determination unit 30, an expected time calculation unit 31, a car speed/acceleration determination unit 32, and a time zone detection unit 33. The standby mode elevator car determination unit 29 determines whether the elevator car is in a standby mode or not. When determination is made that the elevator car is in a standby mode, the parking floor determination unit 30 determines a floor where the car in the standby mode parks. The expected time calculation unit 31 calculates expected time TA of next new hall call occurrence for the elevator car in the standby mode. The car speed/acceleration determination unit 32 sets car speed and car acceleration when the elevator car in the standby mode is moved to the floor where the car parks, in the expected time TA. The time zone detection unit 33 takes out a time zone on that occasion when each of the units 30 to 32 makes determination.
[0031]
The standby mode elevator car control portion 10 determines an elevator car in a standby mode in accordance with the frequency in use of the elevator car at that point of time while using the aforementioned units to move the elevator car to a predetermined floor where the car parks. The standby mode elevator car control portion 10 executes speed and acceleration control of the elevator car on this occasion.
[0032]
First, the standby mode elevator car determination unit 29 determines whether the elevator car is in a standby mode or not, based on the car speed, the moving
13

direction, etc. given from the hall call data 12, the car call data 14 and the current car state data 24 of the elevator car 1 to be controlled. Specifically, when operation service of the elevator car for users is completed so that the elevator car is in a standby mode, determination can be made that the elevator car is in a standby mode, based on the fact that there is neither hall call registration nor car call registration, the fact that the elevator car is in a stopped state and in no moving direction, and the fact that the elevator car is not currently in a floor where the car parks.
[0033]
When the standby mode elevator car determination unit 29 determines that the elevator car 1 to be controlled is an elevator car in a standby mode, the parking floor determination unit 30 sets the floor where the car parks. The floor where the car parks is determined with reference to the parking floor setting table 25 set on the building side in an initial stage or based on the average hall call occurrence rate data 26. In the case of a collectively managed elevator group, the floor where each car in a standby mode parks is set with reference to data of all car positions, etc.
[0034]
For example, when a floor estimated to be most liable to have hall call occurrence is set as the floor where the car in a standby mode parks, the parking floor determination unit 30 extracts a time zone corresponding to the current time from the time zone detection unit 33 and refers to the average hall call occurrence rate data 26 provided as a database using the past hall call history data 21 and the past car call history data 22 etc. The average hall call occurrence rate data 26 shown in Fig. 3 indicate the probabilities of average hall call occurrence, have time zones 35 and traffic flow modes 36 and have ascending directions and descending directions in respective floors in accordance with each time zone 35.
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[0035]
When the current time zone 35 is "11:15-11:30" and the traffic flow mode 36 is "normal 1 mode", the probabilities of average hall call occurrence in respective floors each of which is the sum of the probability in the ascending direction and the probability in the descending direction are compared. On this occasion, probabilities of occurrence per week or probabilities of occurrence per hour etc. are used as the probabilities of occurrence. In this example, the probability of average hall call occurrence in the ascending direction 37 in the first floor is "0.28" which is a larger value than the sum of probabilities of average hall call occurrence in any other floor. Accordingly, the first floor which is a leading candidate for next hall call occurrence is determined as a floor where the car in the standby mode parks.
[0036]
According to such determination of the floor where the car in the standby mode parks, the floor high in the frequency of hall call occurrence in substantially the same time zone is determined as the floor where the car in the standby mode parks, based on the past hall call occurrence frequency history. Accordingly, the elevator car 1 can be allocated so that users in a floor statistically high in the probability of average hall call occurrence are not kept waiting.
[0037]
Then, the expected time calculation unit 31 calculates expected time TA of next hall call occurrence to be registered newly, by using the average hall call occurrence time interval data 27 provided as a database based on the hall call history data 21, etc. As schematically shown in Fig. 4, the average hall call occurrence time interval data 27 has time zones 35 and traffic flow modes 36 and has average hall call occurrence periods in the ascending direction and in the descending direction in
15

respective floors in accordance with each time zone 35. The expected time calculation unit 31 first acquires a time zone corresponding to the current time from the time zone detection unit 33 and compares the average hall call occurrence time intervals in the ascending direction and in the descending direction in respective floors in the "normal 1 mode" in the time zone "11:15-11:30" to thereby determine that an average hall call occurrence time interval 38 in the ascending direction in the first floor is "117 seconds" which is the minimum average occurrence time TB.
[0038]
Although the minimum average occurrence time TB can be used as the expected time TA, the elapsed time since the time point of immediately preceding hall call occurrence is measured here by a timer 34. When the elapsed time TC up to the current time is 20 seconds, the expected time TA is calculated as TB-TC =117 seconds - 20 seconds = 97 seconds.
[0039]
As another embodiment, a pedestrian flow situation on the elevator hall side may be considered with reference to the pedestrian flow situation history data 23 based on the pedestrian flow detection data 18 given from the pedestrian flow sensors 17A to 17D so that when the pedestrian flow on the elevator hall side is detected, an expected time of 17 seconds required for movement to the position of the pedestrian flow sensor and the elevator hall may be further subtracted so that, for example, a time of 80 seconds is set as the expected time TA. Alternatively, the probability of average hall call occurrence in the floor where the car parks, acquired from the aforementioned average hall call occurrence rate data 26 shown in Fig. 3 may be reflected on the expected time TA.
[0040]
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Fig. 13 shows operation characteristic of the elevator car 1. In Fig. 13, the horizontal axis expresses time and the vertical axis expresses a floor in the height direction. Assume now that the standby mode elevator car determination unit 29 determines that the elevator car 1 stopped in the position of the tenth floor is an elevator car in a standby mode. In a conventional elevator, the elevator car 1 is then moved to the floor where the car parks, as represented by normal operation characteristic 51 with the same car speed as that at the time of normal operation. However, when the expected time calculation unit 31 in this embodiment calculates the expected time TA of next hall call occurrence as described above, the elevator car 1 is moved to the floor where the car parks, since the movement start time 50 based on low car speed operation characteristic 52. Although specific setting of the low car speed operation characteristic 52 will be described later, at least one of lower car speed and lower car acceleration than those in the normal operation characteristic 51 is used so that the elevator car 1 will arrive at the floor where the car parks, in the expected time TA.
[0041]
When the expected time TA is not longer than a time TD of arrival at the floor where the car parks, based on the conventional normal operation characteristic 51, the same car speed and acceleration as those in the conventional normal operation characteristic 51 are used because it is impossible to use at least one of the lower car speed and the lower car acceleration than those in the normal operation characteristic 51.
[0042]
According to such an elevator, expected time TA of next hall call occurrence for an elevator car in a standby mode can be calculated and either or both of car speed
17

and car acceleration can be set so that the elevator car 1 will arrive at the floor where the car parks, in the expected time TA. Accordingly, at least one of car speed and car acceleration of the elevator car 1 in a standby mode can be set to be reduced in accordance with the calculated expected time TA, that is, because the time up to arrival at the floor where the car parks becomes long as the expected time TA becomes long, so that the energy saving effect can be improved.
[0043]
Because the hall call occurrence time interval data 27 of Fig. 4 provided as a database using the hall call history data 21 is referred to so that the expected time TA is calculated by use of an average hall call occurrence time interval corresponding to the time zone, the elevator car in a standby mode can be moved to the floor where the car parks, at a car speed and a car acceleration according to the utilization form peculiar to the building in which the elevator is disposed.
[0044]
A method of specifically determining the speed or acceleration of the elevator car in a standby mode by using the expected time TA will be described below.
[0045]
The car speed/acceleration determination unit 32 acquires a time zone corresponding to the current time from the time zone detection unit 33 and refers to the car speed/acceleration setting table 28 shown in Fig. 5 by using the expected time TA calculated by the expected time calculation unit 31 to acquire at least one of a smaller car speed or acceleration than that at the time of normal operation. In the car speed/acceleration setting table 28, the speed (maximum speed) and acceleration of the elevator car 1 in a standby mode are set in accordance with each divided time zone and each divided expected time TA, but actual numerical values indicating the car speed
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and the car acceleration in Fig. 5 are omitted.
[0046]
The time zone is divided into a power peak suppression management time zone 39 requiring power peak suppression and a power saving management time zone 40 requiring power saving. For example, in the power peak suppression management time zone 39 requiring power peak suppression and expressed as "11:00-15:00", car speeds and car accelerations are set so that priority is given to reduction of the maximum speed in order to give greater importance to power peak suppression. On the other hand, in the power saving management time zone 40 which is the other time zone, car speeds and car accelerations are set so that priority is given to reduction of car acceleration in order to give greater importance to power saving. On the other hand, the expected time TA is divided into a time shorter than 30 seconds, a time not shorter than 30 seconds but shorter than 60 seconds, a time not shorter than 60 seconds but shorter than 120 seconds, a time not shorter than 120 seconds but shorter than 180 seconds, and a time not shorter than 180 seconds.
[0047]
In the power peak suppression management time zone 39, reduced car speeds v2 to v5 and slightly reduced car accelerations Bdv/dt to Edv/dt are registered so that priority is given to reduction of car speed in a zone in which the expected time TA is not shorter than 30 seconds. On the other hand, in the power saving management time zone 40, reduced car accelerations Gdv/dt to Jdv/dt and slightly reduced car speeds v7 to vlO are registered so that priority is given to reduction of car acceleration in a zone in which the expected time TA is not shorter than 30 seconds. Either in the power peak suppression management time zone 39 or in the power saving management time zone 40, in the zone in which the expected time TA is shorter than 30 seconds, the
19

expected time TA is so short that the elevator car cannot be moved at a lower speed and a lower acceleration than those at the time of normal operation. Accordingly, in the zone in which the expected time TA is shorter than 30 seconds, the same car speed and the same car acceleration as those at the time normal operation are used as shown in Fig. 5.
[0048]
Values of the expected time TA are set so that the car speed and the car acceleration become lower as the expected time becomes longer. It is now important that the car speed and the car acceleration are not simply reduced but are set so that the elevator car in the standby mode will arrive at the floor where the car parks, in the expected time TA of next hall call occurrence as shown in Fig. 13 which will be described later. Values in the car speed/acceleration setting table 28 shown in Fig. 5 are set in consideration of this condition.
[0049]
When the determined time zone is the power peak suppression management time zone 39 after the car speed/acceleration determination unit 32 first determines whether the converted time zone is the power peak suppression management time zone 39 or the power saving management time zone 40, based on the aforementioned car speed/acceleration setting table 28 shown in Fig. 5, car speed and car acceleration corresponding to the interval of the expected time TA calculated by the expected time calculation unit 31 in the power peak suppression management time zone 39 are extracted. On the other hand, when the current time zone is the power saving management time zone 40, car speed and car acceleration corresponding to the interval of the expected time TA in the power saving management time zone 40 are extracted.
[0050]
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Also in this case, the car speed and the car acceleration may be calculated by arithmetic operation in accordance with the value of the expected time TA instead of the car speed/acceleration setting table 28. In any case, the energy saving effect when the car is moved to the floor where the car parks can be improved in such a manner that at least one of car speed and car acceleration becomes lower as the expected time TA becomes longer in order to obtain car speed and car acceleration for movement of the car to the floor where the elevator car in a standby mode parks, in accordance with the value of the expected time TA of next hall call occurrence. Although it is assumed that the car speed/acceleration setting table 28 is generated at an initial stage of operation of the elevator and stored in the data storage portion 9, the car speed and acceleration may be not generated in advance but calculated in each case so that the same processing can be executed.
[0051]
The difference between the car speed/acceleration set in the power peak suppression management time zone 39 and the car speed/acceleration set in the power saving management time zone 40 shown in Fig. 5 will be described below with reference to Figs. 6 to 9.
[0052]
Fig. 6 is a characteristic graph showing standby operation car speed characteristic 42 in the power peak suppression management time zone 39 in comparison with normal operation car speed characteristic 41. Fig. 7 is a characteristic graph showing standby operation car acceleration characteristic 44 in the power peak suppression management time zone 39 in comparison with normal operation car acceleration characteristic 43 likewise. The standby operation car speed characteristic 42 shown in Fig. 6 is formed so that the car speed decreases successively
21

in accordance with the expected time TA divided into a plurality of zones. In any zone of the expected time TA except the zone not longer than 30 seconds, a car speed lower than that in the normal operation car speed characteristic 41 is set. The standby operation car acceleration characteristic 44 shown in Fig. 7 is formed so that the car acceleration decreases successively in accordance with the expected time TA divided into a plurality of zones likewise. In any zone of the expected time TA except the zone not longer than 30 seconds, a car acceleration slightly lower than that in the normal operation car acceleration characteristic 43 is set. However, the car speed decreasing rate in accordance with each zone of the expected time TA in the standby operation car speed characteristic 42 shown in Fig. 6 is set to be higher than the car acceleration decreasing rate in accordance with each zone of the expected time TA in the standby operation car acceleration characteristic 44 shown in Fig. 7.
[0053]
Accordingly, when the current time zone is the power peak suppression management time zone 39, the expected time TA, for example, of 97 seconds calculated by the expected time calculation unit 31 is used for calculating a standby operation car speed and a standby operation car acceleration based on the standby operation car speed characteristic 42 lower than the normal operation car speed characteristic 41 shown in Fig. 6 and the standby operation car acceleration characteristic 44 slightly lower than the normal operation car acceleration characteristic 43 shown in Fig. 7.
[0054]
Therefore, the car speed/acceleration determination unit 32 extracts a car speed and a car acceleration by using the car speed/acceleration setting table 28 shown in Fig. 5 so that emphasis is put on reduction of car operation speed in standby
22

operation in comparison with normal operation in the power peak suppression management time zone 39, and priority is given to reduction of maximum speed to thereby give greater importance to power peak suppression.
[0055]
On the other hand, Figs. 8 and 9 are characteristic graphs showing standby operation car speed characteristic 45 and standby operation car acceleration characteristic 46 in the power saving management time zone 40. The standby operation car speed characteristic 45 shown in Fig. 8 is formed so that the car speed decreases successively in accordance with the expected time TA divided into a plurality of zones. In any zone of the expected time TA except the zone not longer than 30 seconds, a slightly lower car speed than that in normal operation car speed characteristic 41 is set. The standby operation car acceleration characteristic 46 shown in Fig. 9 is formed likewise so that the car acceleration decreases successively in accordance with the expected time TA divided into a plurality of zones. In any zone of the expected time TA except the zone not longer than 30 seconds, a lower car acceleration than that in normal operation car acceleration characteristic 43 is set.
[0056]
In comparison between the two, the standby operation car speed characteristic 45 shown in Fig. 8 indicates slightly lower car speed setting than that in the normal operation car speed characteristic 41 whereas the standby operation car acceleration characteristic 46 shown in Fig. 9 indicates lower acceleration setting than that in the normal operation car acceleration characteristic 43.
[0057]
The difference between the power peak suppression management time zone 39 and the power saving management time zone 40 is as follows. As is obvious from
23

comparison between Figs. 6 and 8, the standby operation car speed characteristic 42 for achieving power peak suppression is used to give priority to reduction of car speed when the current time zone is the power peak suppression management time zone 39. Similarly, as is obvious from comparison between Figs. 7 and 9, the standby operation car acceleration characteristic 46 for achieving power saving is used to give priority to reduction of car acceleration when the current time zone is the power saving management time zone 40.
[0058]
When greater importance is given to power peak suppression shown in Figs. 6 and 7, there is provided such characteristic that the car speed and the car acceleration become lower as the expected time TA shown in the horizontal axis becomes longer, especially the standby operation car speed characteristic 42 gives priority to reduction of car speed. In other words, when the normal operation car speed characteristic 41 and the normal operation car acceleration characteristic 43 are regarded as standards, the car speed decreasing rate to the car speed value in normal operation is set to be larger than the car acceleration decreasing rate so that greater importance is given to power peak suppression. Because the time zone in which greater importance is given to power peak suppression is a time zone in which balance between total power generation and total power consumption is strained in view of the whole power system, there is a large effect in reducing total power consumption to give a margin to power demand-and-supply balance when power peak suppression is attained on the whole elevator in the power system.
[0059]
On the contrary, the standby operation car speed characteristic 45 and the standby operation car acceleration characteristic 46 in the power saving management
24

time zone 40 give greater importance to power saving, that is, reduction of power consumption as shown in Figs. 8 and 9, so that especially priority is given to reduction of car acceleration in accordance with the standby operation car acceleration characteristic 46. That is, because the car acceleration decreasing rate to the car acceleration value in normal operation is set to be larger than the car speed decreasing rate, greater importance can be given to reduction of power consumption.
[0060]
Thus, when the current time zone is the power saving management time zone 40, the car speed/acceleration determination unit 32 refers to the car speed/acceleration setting table 28 shown in Fig. 5 by using the expected time TA calculated by the expected time calculation unit 31 and extracts a standby operation car speed from the standby operation car speed characteristic 45 slightly lower than the normal operation car speed characteristic 41 shown in Fig. 8 and a standby operation car acceleration from the standby operation car acceleration characteristic 46 sufficiently lower than the normal operation car acceleration characteristic 43 shown in Fig. 9. Therefore, the standby operation in the power saving management time zone 40 gives emphasis to reduction of car acceleration compared with the normal operation, so that a car speed and a car acceleration to give priority to reduction of car acceleration are extracted to achieve power saving.
[0061]
Incidentally, power consumption p at the time of movement of the elevator car 1 can be expressed approximately in the following expression 1:
[0062]
p = v x {(Sm)x(dv/dt)+Amxg} - (Expression 1)
in which v is the speed (maximum speed) of the elevator car 1, 2m is the total weight
25

of the elevator car 1, the in-car load, the balance weight 2, etc., dv/dt is the acceleration of the elevator car 1, Am is the weight difference (unbalance weight) between the total weight of the elevator car 1 and the balance weight 2, and g is the gravitational acceleration.
As is obvious from this expression, power consumption p_ decreases in proportion to the maximum speed v of the elevator car 1 when the maximum speed v is reduced. Accordingly, reduction in the maximum speed v of the elevator car 1 permits the power peak to be reduced.
[0063]
Figs. 10 to 12 show operation patterns different in terms of car speed and car acceleration. In an operation pattern 47 shown in Fig. 10, the maximum speed v in normal operation is expressed in a horizontal line portion while the acceleration dv/dt is expressed in an inclined line portion. On the other hand, Fig. 11 shows an operation pattern 48 in the power peak suppression management time zone 39. Because the maximum speed v is lower than that in the operation pattern 47 in normal operation, the power peak can be reduced likewise. However, when the maximum speed v of the elevator car 1 is reduced as shown in the operation pattern 48, the moving time becomes longer than that in the operation pattern 47 in normal operation so that the total power consumption is unchanged.
[0064]
As is obvious from the expression 1, power consumption p_ can be reduced when the acceleration dv/dt of the elevator car 1 is reduced. When the acceleration dv/dt is made lower than that in the operation pattern 47 in normal operation while the maximum speed v expressed in the horizontal line portion is made equal to that in normal operation as shown in an operation pattern 49 shown in Fig. 12, increase of the
26

moving time can be suppressed and the total power consumption can be suppressed in comparison with Fig. 11. Accordingly, in the power saving management time zone 40, the acceleration dv/dt may be set so that priority is given to reduction of car acceleration as shown in the operation pattern 49.
[0065]
In this manner, in the car speed/acceleration setting table 28 shown in Fig. 5, car speed and acceleration values are set in accordance of the plurality of time zones and the plurality of zones of the expected time TA. On this occasion, at least one of car speed and car acceleration may be set to be lower than that in normal operation because the power peak suppression management time zone 39 can be formed so that only the car speed is set to be lower than that in normal operation while the power saving management time zone 40 can be formed so that only the car acceleration is set to be lower than that in normal operation.
[0066]
Upon reception of the expected time TA calculated by the expected time calculation unit 31, the car speed/acceleration determination unit 32 shown in Fig. 1 determines the car speed and the car acceleration for moving the elevator car 1 in the standby mode to the floor where the car parks by referring to the car speed/acceleration setting table 28 while using the time zone detection unit 33. The determined car speed and acceleration values are transmitted, as instructions to give the car speed and the car acceleration to the elevator car in the standby mode, to the main control portion 8. The main control portion 8 moves the elevator car 1 to the floor where the car parks while controlling the car speed and the car acceleration through the power converter 6 of the elevator car in the standby mode.
[0067]
27

According to such an elevator, the time zone is divided into a power peak suppression management time zone 39 and a power saving management time zone 40 and the car speed and the car acceleration are set in accordance with each time zone when the elevator car 1 in the standby mode is moved to the floor where the car parks. Accordingly, in the time zone in which greater importance is given to power peak suppression, the car speed and the car acceleration can be set so that priority is given to reduction of maximum speed. On the other hand, in the other time zone in order to give emphasis to power saving, the car speed and the car acceleration can be set so that priority is given to reduction of car acceleration. Consequently, power peak suppression or reduction of power consumption can be attained in accordance with each time zone.
[0068]
Moreover, because the expected time TA is divided into a plurality of zones so that the car speed and the car acceleration are controlled in accordance with each zone, at least one of car speed and car acceleration for moving the elevator car 1 can be reduced in accordance with the length of the expected time TA so that the elevator car 1 will arrive at a predetermined floor where the car parks, in the expected time TA. Accordingly, there is no influence on elevator users making next hall calls, so that user-friendliness is not spoiled. Because such control is performed when the elevator car in the standby mode is moved to the floor where the car parks, there is no passenger in the elevator car 1 in the standby mode and the elevator car 1 is moved to the floor where the car parks without any hall call occurrence. Accordingly, the users in the hall do not receive any influence caused by change of waiting time even if the boarding time is changed according to reduction of the car speed or the car acceleration.
28

[0069]
Incidentally, the expected time TA can be set in advance by referring to the history at an initial stage or can be changed based on accumulated history data. With respect to the speed and acceleration of the elevator car 1 to be moved to the floor where the car parks, another type expected time calculation unit 31 may be used because substantially the same effect can be expected even if a time slightly longer than the expected time TA calculated by the expected time calculation unit 31 is selected.
[0070]
For example, Fig. 5 shows the case where the expected time TA in Fig. 5 is divided into a plurality of zones so that the car speed and the car acceleration are set in accordance with each zone. When the elevator car 1 in the standby mode is moved to the floor where the car parks, the time of movement, the hall call occurrence time interval in the traffic state at this time, the frequency of hall call occurrence (e.g. expressed in cycles per minute, etc.), the frequency in use of the elevator car or the traffic volume in the building may be used as an index. For example, when the hall call occurrence time interval in the traffic state at this time is used, the car speed and the car acceleration may be set to be reduced in accordance with the length of the hall call occurrence time interval as the hall call occurrence time interval becomes long. When the frequency of occurrence, the frequency in use or the traffic volume is used, the car speed and the car acceleration may be set to be reduced in accordance with the frequency or traffic volume as the frequency of occurrence, the frequency in use or the traffic volume becomes low.
[0071]
Fig. 14 shows an elevator according to another embodiment of the invention.
29

Parts identical to those in the previous embodiment are referred to by the same numerals so that detailed description thereof will be omitted while only a different portion will be described.
[0072]
This embodiment is different in the method of setting the car speed and the car acceleration for moving the elevator car 1 in the standby mode to the floor where the car parks. There are provided floor data 53 in which data of floor height, etc. are stored in the data storage portion 9, a distance calculation unit 54 which calculates a travel distance XA between the current position of the elevator car 1 in the standby mode and the floor where the car parks by using the floor data 53, and a car speed index calculation unit 55 which calculates a car speed index expressed in XA/TA by using the expected time TA already calculated by the expected time calculation unit 31 and the travel distance XA calculated by the distance calculation unit 54. The car speed/acceleration setting table 28 in the data storage portion 9 is changed so that the corresponding car speed and acceleration can be extracted based on the car speed index calculated by the car speed index calculation unit 55.
[0073]
That is, as shown in Fig. 15, in the car speed/acceleration setting table 28, the vertical direction indicates a car speed index (XA/TA) divided into five zones, that is, a zone of a car speed lower than rated car speed x 0.25, a zone of a car speed not lower than rated car speed x 0.25 but lower than rated car speed x 0.5, a zone of a car speed not lower than rated car speed x 0.5 but lower than rated car speed x 0.75, a zone of a car speed not lower than rated car speed x 0.75 but lower than rated car speed and a zone of a car speed not lower than rated car speed, whereas the horizontal direction is divided into a power peak suppression management time zone 39 expressed as a time
30

zone 11:00-15:00 and a power saving management time zone 40 expressed as the other time zone so that car speeds v and car accelerations dv/dt are set in accordance with the car speed indices.
[0074]
For example, in the power peak suppression management time zone 39, when the car speed index is not lower than rated car speed x 0.25 but lower than rated car speed x 0.5, the car speed is v4 and the car acceleration is Ddv/dt so that the elevator car can arrive at the floor where the car parks before the expected time TA if the car speed v4 is set to be rated car speed x 0.6. Specific values of the car speed and acceleration may be set based on such a thought. The other thought is completely the same as in the case of Fig. 5, for example, in terms of the power peak suppression management time zone 39, the power saving management time zone 40, etc. Then, the car speed and acceleration extracted from the car speed/acceleration setting table 28 and determined by the car speed/acceleration determination unit 32 are transmitted as car speed and acceleration instructions to the main control portion 8 so that the elevator car in the standby mode is moved in accordance with the instructions.
[0075]
According to such an elevator, the car speed index calculated by the car speed index calculation unit 55 can be used in the situation as shown in Fig. 13 so that the elevator car 1 in the standby mode can arrive at the floor where the car parks, in the expected time TA of next hall call occurrence more surely. Specifically, the travel distance XA between the current position of the elevator car 1 in the standby mode and the floor where the car parks, for example, the travel distance XA from the tenth floor to the first floor in Fig. 13, and the car speed index (XA/TA) as an index of car speed allowing the elevator car to arrive at the floor where the car parks, in the expected time
31

TA are calculated so that the car speed and acceleration of the elevator car 1 in the standby mode can be extracted in accordance with the car speed index calculated with reference to Fig. 15. Addition of information concerned with the distance between the current position of the elevator car 1 in the standby mode and the floor where the car parks permits the car speed and acceleration to be set more appropriately.
[0076]
In comparison with the previous embodiment, because the car speed and acceleration are set with reference to the travel distance XA of the elevator car 1 in the standby mode to the floor where the car parks, the car speed and acceleration can be set more accurately in accordance with the expected time TA so that the elevator car 1 can arrive at the floor where the car parks. As a result, power peak suppression or reduction of power consumption can be attained without spoiling user-friendliness, that is, without increase in waiting time.
32

What is claimed is:
1. An elevator comprising:
an elevator controller which controls up/down movement of an elevator car;
a standby mode elevator car determination unit which determines an elevator car in a standby mode when the elevator car is not in a floor where the car parks and there is neither hall call registration nor car call registration;
a parking floor determination unit which determines a floor where the elevator car in the standby mode parks when determination is made that the elevator car is in the standby mode; and
a car speed/acceleration determination unit which determines a car speed and a car acceleration for moving the elevator car in the standby mode to the floor where the car parks; wherein:
the car speed/acceleration determination unit is provided so that at least one of the car speed and the car acceleration for moving the elevator car in the standby mode to the floor where the car parks becomes lower than that at the time of normal operation.
2. An elevator according to Claim 1, wherein:
the parking floor determination unit determines a floor high in the frequency of hall call occurrence in substantially the same time zone as the floor where the car parks, based on past hall call occurrence frequency history.
3. An elevator according to Claim 1, wherein:
the parking floor determination unit determines a floor high in the frequency of hall call occurrence in substantially the same time zone as the floor where the car parks, based on past hall call occurrence frequency history; and
the car speed/acceleration determination unit divides the hall call occurrence
frequency into zones so that at least one of the car speed and the car acceleration for arrival of the car at the floor where the car parks becomes lower as the hall call occurrence frequency in the zones becomes lower.
4. An elevator according to Claim 1, further comprising:
an expected time calculation unit which calculates expected time of next hall call occurrence after determination is made that the elevator car is in a standby mode; wherein:
the car speed/acceleration determination unit selects at least one of the car speed and the car acceleration for arrival of the car at the floor where the car parks, in the expected time.
5. An elevator according to Claim 1, further comprising:
an expected time calculation unit which calculates expected time of next hall call occurrence after determination is made that the elevator car is in a standby mode; wherein:
the car speed/acceleration determination unit divides the expected time into zones so that at least one of the car speed and the car acceleration for arrival of the car at the floor where the car parks becomes lower as the expected time in the zones becomes longer.
6. An elevator according to Claim 1, further comprising:
an expected time calculation unit which calculates expected time of next hall call occurrence after determination is made that the elevator car is in a standby mode; and
a distance calculation unit which calculates a travel distance between the position of the elevator car in the standby mode determined by the standby mode elevator car determination unit and the floor where the car parks; wherein:
a plurality of zones are provided in accordance with the rate of the travel distance to the expected time so that the car speed/acceleration determination unit selects at least one of the car speed and the car acceleration for moving the elevator car in the standby mode to the floor where the car parks, in accordance with the zones.
7. An elevator according to Claim 1, further comprising:
an expected time calculation unit which calculates expected time TA of next hall call occurrence after determination is made that the elevator car is in a standby mode; and
a distance calculation unit which calculates a travel distance XA between the position of the elevator car in the standby mode determined by the standby mode elevator car determination unit and the floor where the car parks; wherein:
a plurality of zones are provided in accordance with the rate XA/TA; and
the car speed/acceleration determination unit determines the car speed/ acceleration so that at least one of the car speed and the car acceleration for moving the elevator car in the standby mode to the floor where the car parks becomes lower as the rate XA/TA becomes smaller.
8. An elevator according to Claim 1, further comprising:
a time zone detection unit provided with a plurality of time zones; wherein: the time when the elevator car in the standby mode is determined by the standby mode elevator car determination unit is made to correspond to one of the time zones in the time zone detection unit so that the car speed/acceleration determination unit selects at least one group of car speeds and car accelerations set in accordance with the time zones.
9. An elevator according to Claim 1, wherein:
priority is given to reduction of car speed when the current time is in a power
peak suppression management time zone but priority is given to reduction of car acceleration when the current time is in a power saving management time zone.
10. An elevator, substantially as herein described with reference to accompanying drawings and examples.