EP1396455A1

EP1396455A1 - Elevator system

Info

Publication number: EP1396455A1
Application number: EP01934422A
Authority: EP
Inventors: Ikuo Yamato; Hiromi Inaba; Atsuya Fujino
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 2001-05-30
Filing date: 2001-05-30
Publication date: 2004-03-10
Anticipated expiration: 2021-05-30
Also published as: JPWO2003000580A1; EP1396455B1; JP4375020B2; CN1312024C; EP1396455A4; CN1509252A; WO2003000580A1

Abstract

It is an object of the present invention to provide an elevator system that reduces tail codes, that is less influenced by fading, and that speeds communication between a car and a controller.

In one aspect of the present invention, a fixed radio terminal connectable to a car radio terminal can be selected by configuring the system such that the position of the car radio terminal is estimated based on information from an encoder provided on an electric motor that moves up and down the car.

In another aspect of the present invention, fixed radio terminals regularly search for the car radio terminal to keep the car radio terminal always connected to one of the fixed radio terminals and, at the same time, the flag is set in the controller to indicate the fixed radio terminal that is connected.

In still another aspect of the present invention, the car radio terminal regularly searches for the fixed radio terminals to keep the car radio terminal always connected to one of the fixed radio terminals and, at the same time, the flag is set in the controller to indicate the fixed radio terminal that is connected.

Description

TECHNICAL FIELD

The present invention relates to signal communications between the car and the controller of an elevator and more particularly to an elevator communication technology using radio communication.

BACKGROUND ART

Wired communication via a cable constituted by a tail code has been used for communication between the car and the controller of a conventional elevator. A problem with this communication is the cost of cabling work. In addition, an oblique running elevator requires regular or periodical replacement of tail codes and its maintenance cost is another problem.
As a potential means for solving this problem is to transmit a signal between the car and the controller via radio waves. However, considering the radio wave environment in an elevator shaft, there is a possibility that sufficient transmission quality cannot be guaranteed due to a fading caused by reflected waves.
One potential means for solving this problem is a low-power radio system in which a main controller and a plurality of distributed fixed radio terminals are connected via cables and each fixed radio terminal is connected to a mobile radio terminal in the service area. Such a radio system is disclosed in JP-A-7-170558. In this prior art, fixed radio terminals, each of which is connected to the controller via a cable and forms its own service area, are distributed. In this system, when communication is performed between the controller and the mobile radio terminal, data is transmitted between the controller and a fixed radio terminal via cable communication and between the fixed radio terminal and the mobile radio terminal via radio communication.

DISCLOSURE OF THE INVENTION

When communication is performed between the controller and the mobile radio terminal, the controller must specify a fixed radio terminal via which communication is performed with the mobile radio terminal. According to the prior-art technology, the controller determines which fixed radio terminal will communicate with the mobile radio terminal by performing polling for the fixed radio terminals. This means that, when the number of fixed radio terminals is increased, it takes time to search for the mobile radio terminal and, therefore, the problem is that elevator control information, which must be transmitted in real time, cannot be transmitted.
It is an object of the present invention to provide an elevator system that can reduce tail codes, that is less influenced by fading, and that speeds communication between the car and the controller.
In one aspect of the present invention, a fixed radio terminal connectable to a car radio terminal can be selected by configuring the system such that the position of the car radio terminal is estimated based on information from an encoder provided on an electric motor that moves up and down the car.
In another aspect of the present invention, the fixed radio terminals regularly or periodically search for the car radio terminal to keep the car radio terminal always connected to one of the fixed radio terminals and, at the same time, the flag is set in the controller to indicate the fixed radio terminal that is connected.
In still another aspect of the present invention, the car radio terminal regularly or periodically searches for the fixed radio terminals to keep the car radio terminal always connected to one of the fixed radio terminals and, at the same time, the flag is set in the controller to indicate the fixed radio terminal that is connected.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a configuration diagram of an elevator system according to the present invention. FIG. 2 is an interrupt flowchart of a controller. FIG. 3 is a configuration diagram of a fixed radio terminal flag in the controller. FIG. 4 is a data transmission flowchart of the controller. FIG. 5 is a reception interrupt flowchart of a fixed radio terminal. FIG. 6 is a data reception flowchart of a car radio terminal. FIG. 7 is a car radio terminal search flowchart of the fixed radio terminal. FIG. 8 is a reception interrupt flowchart of the controller. FIG. 9 is an interrupt flowchart of the car radio terminal. FIG. 10 is a reception interrupt flowchart of the fixed radio terminal. FIG. 11 is a configuration diagram of another elevator system according to the present invention. FIG. 12 is a configuration diagram of another elevator system according to the present invention. FIG. 13 is a cross section diagram of the elevator system according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Some embodiments of an elevator system according to the present invention will be described below with reference to the drawings.
FIG. 1 shows the configuration of an elevator system in one embodiment of the present invention.
Referring to FIG. 1, fixed radio terminals 20-23 are distributed in the elevator shaft with the neighboring fixed radio terminals 20-23 connected by a transmission line. A controller 10 controlling the operation of the elevator is also connected to the fixed radio terminals 20-23 so that communication can be performed.
A car 30 of the elevator has a car radio terminal 31 that communicates with the fixed radio terminals 20-23 via radio waves. A counterweight 40, as well as the car 30, is suspended in the pickup and supply arrangement via a sheave 50 and a pulley 60. An electric motor 51 is connected to the sheave 50, and this electric motor moves up and down the car 30. An encoder 52 is connected to the electric motor, and the controller 10 estimates the position of the car based on the output of this encoder.
The controller 10 controls the operation while transmitting a signal to and from the car radio terminal 31. For example, a door open/close command or car position information is transmitted from the controller 10 to the fixed radio terminals 20-23 via cables and then transmitted from (one of) the fixed radio terminals 20-23 to the car radio terminal 31 via radio waves. Conversely, the signal generated by a floor selection registration button in the car is sent from the car radio terminal 31 to the fixed radio terminals 20-23 via radio waves and is transmitted from the fixed radio terminal 20-23 to the controller 10 via the cable. Radio waves used in this case are short distance radio waves that requires no license or permission, for example, weak radio waves with the communication range of 10m or shorter and with the transmission power of 1mW or lower. By using short distance radio waves as in this embodiment, the radio waves are not influenced by fading and therefore the system can prevent deterioration in transmission quality.
FIGS. 2-6 show the operation of the controller 10, the fixed radio terminals 20-23, and the car radio terminal 31 in the embodiment shown in FIG. 1.
FIG. 2 shows an interrupt task in which the controller 10 estimates the position of the car 30 and determines a fixed radio terminal connectable to the car radio terminal 31.
The controller 10 regularly or periodically generates a timer interrupt to estimate the position of the car 30 (step 201). After the timer interrupt is generated, the controller 10 reads position information on the car 30 from the encoder 52 provided on the electric motor 51 that moves up and down the car 30 (steps 202 and 203). The controller 10 determines the nearest fixed radio terminal based on this car position information (step 204) and updates a fixed radio terminal flag allocated in a recording unit (not shown) in the controller 10 (step 205). The fixed radio terminal flag, such as the one shown in FIG. 3, is data consisting of bits each indicating whether the corresponding fixed radio terminal is connectable. By executing this operation regularly, the controller 10 can constantly keep track of the fixed radio terminal that can be connected to the car 30.
FIG. 4 shows a task that that transmits data from the controller 10 to the car radio terminal 31 via a fixed radio terminal.
The controller 10 activates this task to send data to the car radio terminal 31. First, the controller 10 checks the fixed radio terminal flag described above (step 401), selects a fixed radio terminal connectable to the car radio terminal 31, and connects to that fixed radio terminal (step 402). After that, the controller 10 outputs a request to connect to the car radio terminal 31 (step 403) and then sends data, which will be transmitted next, to the fixed radio terminal (step 404).
FIG. 5 shows the operation of a fixed radio terminal. Upon receiving a reception interrupt, the fixed radio terminal checks if the input is a connection request or data (step 501). When the input is a connection request, the fixed radio terminal issues a call to the car radio terminal 31 (step 502) and, if a response is received, connects to the car radio terminal (steps 503, 504). If no response is received, the fixed radio terminal notifies the controller 10 that no response was received (steps 503, 505). When the input is data, the fixed radio terminal sends the data according to the destination (steps 506-509).
FIG. 6 shows the operation of the car radio terminal 31.
When a reception interrupt is caused (step 601), the car radio terminal 31 receives data from the controller 10 to perform a predetermined operation such as the display of the car position (step 602).
In this embodiment, the controller 10 can estimate the position of the car 30 based on the data received from the encoder 52 as described above. Therefore, because the controller 10 can transmit data to the car radio terminal 31 via a fixed radio terminal connectable to the car radio terminal 31 without performing extra polling processing, the system can transfer data more quickly than the conventional system.
With reference to FIG. 7 and FIG. 8, another embodiment of the present invention will be described.
FIG. 7 is a car connection task executed by a fixed radio terminal according to the present invention. A fixed radio terminal regularly generates a timer interrupt to check if there is the car radio terminal 31 within the range where the radio wave reaches (step 701). After generating the timer interrupt, the fixed radio terminal calls the car radio terminal 31 (step 702) and if the response is received, sets the flag in the controller 10 (steps 703, 704). If no response is received, the fixed radio terminal notifies the controller 10 that no response was received (step 705).
FIG. 8 shows the operation of the controller 10. In response to a reception interrupt (step 801), the controller 10 checks the input and, if the input is a flag (step 802), confirms the issuing fixed radio terminal (step 803) and then updates the fixed radio terminal flag (step 804). If the input is data, the controller 10 receives the data (step 805).
By executing the operation described above, the controller 10 can always keep track of a fixed radio terminal connectable to the car radio terminal 31. Data is transmitted from the controller 10 to the car radio terminal 31 in the same way as shown in FIG. 4 to FIG. 6. The controller 10 checks the fixed radio terminal flag and selects a fixed radio terminal connectable to the car radio terminal 31 as shown in FIG. 4. The controller 10 connects to that fixed radio terminal, issues a request to connect to the car radio terminal 31, and sends transmission data to the fixed radio terminal. In response to a reception interrupt, a fixed radio terminal checks if the input is a connection request or data as shown in FIG. 5. When the input is a connection request, the fixed radio terminal calls the car radio terminal 31 and, if the response is received, connects to it. If no response is received, the fixed radio terminal notifies the controller 10 that no response was received. When the input is data, the fixed radio terminal sends data according to the destination. In response to a reception interrupt, the car radio terminal 31 receives data from the controller 10 as shown in FIG. 6 and performs operation such as the display of the car position.
Thus, in this embodiment, the controller 10 can select a connectable fixed radio terminal using data in the fixed radio terminal flag. This eliminates the need for performing extra polling operation and allows data to be transmitted to the car via a fixed radio terminal connectable to the car radio terminal 31, making it possible to transfer data more speedily than in the conventional system.
Another embodiment of the present invention will be described with reference to FIG. 9 and FIG. 10.
FIG. 9 shows the interrupt task of the car radio terminal 31. The car radio terminal 31 regularly generates a timer interrupt (step 901). When a timer interrupt is generated, the car radio terminal 31 searches for a connectable fixed radio terminal (steps 903, 904) and connects to the connectable fixed radio terminal (step 905). This keeps the car radio terminal 31 always connected to one of the fixed radio terminals.
The interrupt causes other than a timer interrupt include a reception interrupt and a sending interrupt. When a reception interrupt is generated, the car radio terminal 31 receives data from the connected fixed radio terminal (step 906). When a sending interrupt is generated, the car radio terminal 31 sends data to the connected fixed radio terminal (step 907).
FIG. 10 shows the operation of a fixed radio terminal.
In response to a reception interrupt (step 1001), a fixed radio terminal checks if the input is a connection request or data (step 1002). When the input is a connection request, the fixed radio terminal connects to the car radio terminal 31 (step 1003) and, after the connection, sets the flag in the controller (step 1004). When the input is data, the fixed radio terminal sends data according to the destination (steps 1005-1008). The operation of the controller is the same as that shown in FIG. 8.
Thus, in this embodiment, the controller 10 can select a connectable fixed radio terminal based on data in the fixed radio terminal flag. This eliminates the need for performing extra polling processing and allows data to be transmitted to the car via a fixed radio terminal connectable to the car radio terminal 31, making it possible to transfer data more speedily than in the conventional system.
FIG. 11 shows a still another embodiment of the present invention.
In this embodiment, fixed radio terminals 20-23 are provided on the floors, one for each floor, as well as elevator call buttons 200-203. When an elevator call button is pressed, the call is registered with the controller 10 via a fixed radio terminal. Because a call requested in an elevator hall is registered with the fixed radio terminals 20-30 in this embodiment, there is no need for providing another terminal for a call button.
FIG. 12 shows a still another embodiment of the present invention.
This embodiment is similar to the embodiment shown in FIG. 11 except that an antenna is provided in the elevator hall side of each fixed radio terminal. This allows a mobile radio terminal 70 (cellular phone, personal computer, and so on), which has a short distance radio device, in an elevator hall to communication with the controller 10 via a fixed radio terminal. Information transferred between the mobile radio terminal 70 and the controller 10 includes the following.
When the elevator is used, an elevator call is sent from the mobile radio terminal 70 to the controller 10 for registering the call. Elevator operation information (car position, operation direction) is sent from the controller 10 to the mobile radio terminal 70 and is displayed on the display of the mobile radio terminal 70.
When the elevator is maintained, elevator maintenance information is sent from the controller 10 to the mobile radio terminal 70 and is displayed on the display of the mobile radio terminal 70.
FIG. 13 is a cross section diagram of an elevator shaft according to the present invention.
In this figure, the numeral 200 indicates a fixed radio terminal antenna and the numeral 310 indicates a car radio terminal antenna. In this embodiment, both the fixed radio terminal antenna 200 and the car radio terminal antenna 310 are installed in a position not overlapping with the car and the counterweight in the horizontal projection plane. This configuration puts the fixed radio terminal antenna 200 and the car radio terminal antenna 310 in an arrangement where they can see each other and therefore prevents radio communication between them from being broken.

Claims

An elevator system having a car moving across a plurality of floors in an elevator shaft and a controller controlling an operation of said car, characterized by comprising:

a plurality of fixed radio terminals connected to said controller via transmission lines and distributed within the elevator shaft; a car radio terminal provided on said car; means for detecting a position of said car; and means for selecting said fixed radio terminal that communicates with said car radio terminal via radio waves based on the detection, wherein a signal is transmitted between said controller and said car radio terminal via the selected fixed radio terminal.
An elevator system having a car moving across a plurality of floors in an elevator shaft and a controller controlling an operation of said car, characterized by comprising:

a plurality of fixed radio terminals connected to said controller via transmission lines and distributed within the elevator shaft; a car radio terminal provided on said car; means for detecting a position of said car; and means for selecting one of said plurality of fixed radio terminals based on the detection, wherein a signal is transmitted between said controller and said car radio terminal via the selected fixed radio terminal.
An elevator system having a car moving across a plurality of floors in an elevator shaft and a controller controlling an operation of said car, characterized by comprising:

a plurality of fixed radio terminals distributed within the elevator shaft, at least one of which being connected to said controller via a transmission line; transmission lines connecting between said fixed radio terminals that are neighbors; a car radio terminal provided on said car; an encoder provided on an electric motor driving said car; means for detecting a position of the car based on an output of said encoder; and means for selecting a fixed radio terminal nearest to said car radio terminal based on the detection, wherein a signal is transmitted between said controller and said car radio terminal via the selected fixed radio terminal.
An elevator system having a car moving across a plurality of floors in an elevator shaft and a controller controlling an operation of said car, wherein a plurality of fixed radio terminals connected to said controller via transmission lines and distributed within the elevator shaft; a car radio terminal provided on said car; means for regularly searching for a fixed radio terminal connectable to said car radio terminal for communication and wherein a signal is transmitted between said controller and said car radio terminal via the fixed radio terminal that has been searched for.
An elevator system having a car moving across a plurality of floors in an elevator shaft and a controller controlling an operation of said car, characterized by comprising:

a plurality of fixed radio terminals distributed within the elevator shaft, at least one of which being connected to said controller via a transmission line; transmission lines connecting between said fixed radio terminals that are neighbors; a car radio terminal provided on said car; means for connecting said fixed radio terminal and said car radio terminal existing in a communication range when said car radio terminal and said fixed radio terminal are in the communication range and, at the same time, for sending a connection signal to said controller; means for storing the connection signal that has been sent; and means for selecting a fixed radio terminal, which will communicate with said car radio terminal, based on the stored connection signal when a signal is transmitted between said controller and said car radio terminal.
The elevator system according to claims 1-5,
characterized in that communication between said fixed radio terminal and said car radio terminal is performed via short distance radio waves with an output power of 1mW or lower.
The elevator system according to claims 1-5,
characterized in that said fixed radio terminal is installed in each elevator hall.
The elevator system according to claims 1-5,
characterized in that an antenna is provided on an elevator hall side and on an elevator shaft side of said fixed radio terminal.