JP7691903B2 - Mobile radio control system and mobile radio control method - Google Patents

Description

The present invention relates to a mobile radio control system and a mobile radio control method.

Conventionally, a moving object that moves along a fixed path, such as an elevator car, is connected to an external control device by a cable, and communication is carried out between the moving object (car) and the external control device via the cable. For example, in the case of an elevator car, it is common to connect a cable called a tail cord to the bottom of the car in the hoistway, and to communicate with a control device installed in a machine room or the like via the tail cord.

However, as buildings become taller, the length of the tail cords increases, and the maintenance costs for the tail cords increase.
For this reason, it has been proposed to wirelessly communicate between a moving object such as an elevator car and the outside world, thereby eliminating the need for communication cables such as tail cords.

However, since a moving object such as an elevator car moves, its positional relationship with a fixed object such as a control device is constantly changing, and the wireless quality is not constant, so measures must be taken to ensure good wireless communication.

Patent Document 1 describes a technology that combines position information obtained from a GPS (Global Positioning System) receiver installed on a mobile object such as construction machinery with wireless communication quality information, and when the mobile object communicates, wireless communication is performed using a communication method suitable for each position.

JP 2016-46727 A

As described in Patent Document 1, in the case of a mobile object moving in an environment where location information can be obtained, it is possible to appropriately control the communication method using the location information. In contrast, in cases where the location during movement can only be obtained discretely, such as in the case of an elevator car, the optimal communication method cannot be determined, and there are cases where the communication method is not set appropriately. That is, in the case of an elevator car, the car's position is detected when it is in the door zone near the stopping position of each floor, but when the car is traveling away from the door zone, the exact position is not known, and even if the technology in Patent Document 1 is applied, the communication method may not be set appropriately.

The present invention aims to provide a mobile radio control system and a mobile radio control method that can maintain appropriate wireless communication quality even in an environment where location information can only be obtained discretely.

In order to solve the above problems, for example, the configurations described in the claims are adopted.
The present application includes multiple means for solving the above problems. One example is a mobile body wireless control system in which N (N is an integer equal to or greater than 2) antennas are installed on both the mobile body and the fixed side, and N wireless transmission paths are formed by the N antennas on the mobile body and the N antennas on the fixed side to perform wireless communication, and the transmission frequencies or transmission channels on the N wireless transmission paths are switched to multiple transmission frequencies or transmission channels, respectively, to enable communication.
A mobile body wireless control system according to an example of the present application includes a position acquisition unit that discretely acquires a moving position of a mobile body, a transmission quality collection unit that collects transmission quality during transmission at a plurality of prepared transmission frequencies or transmission channels on N wireless transmission paths, and a combination setting unit that sets an optimal transmission frequency or transmission channel on the N wireless transmission paths based on the moving position of the mobile body acquired by the position acquisition unit and the transmission quality at each transmission frequency or each transmission channel on each wireless transmission path collected by the transmission quality collection unit.

According to the present invention, even in a situation where the position of a moving body can only be obtained discretely, it is possible to determine the optimal transmission frequency or transmission channel for each wireless transmission path, and wireless communication between the moving body and the fixed side can be performed under optimal conditions.
Problems, configurations and effects other than those described above will become apparent from the following description of the embodiments.

FIG. 1 is a configuration diagram showing an overview of wireless transmission in an elevator according to an embodiment of the present invention. FIG. 2 is a block diagram showing an example of a wireless transmission configuration of an elevator according to an embodiment of the present invention. 2 is a block diagram showing an example of the configuration of a radio signal control unit according to an embodiment of the present invention. FIG. 1 is a diagram showing a configuration of a wireless transmission path according to an embodiment of the present invention; FIG. 4 is a diagram illustrating an example of the relationship between signal quality and car distance according to an embodiment of the present invention. FIG. 11 is a diagram showing an example in which the frequency of a wireless transmission path is switched according to an embodiment of the present invention. 5 is a flowchart showing a process for determining a combination of an antenna and a frequency according to an embodiment of the present invention. FIG. 2 is a sequence diagram showing in chronological order the processing performed by a machine room-side wireless control unit and a car-side wireless control unit according to an embodiment of the present invention. 5 is a flowchart showing a process for acquiring a relationship between a cage position and a signal quality according to an embodiment of the present invention. FIG. 11 is a diagram showing an example of changes in speed and time when a car is moving according to an embodiment of the present invention. 10 is a flowchart showing a process for determining antenna/frequency allocation according to an embodiment of the present invention. 1A and 1B are diagrams illustrating an example of door zone detection and car movement according to an embodiment of the present invention. 1A and 1B are diagrams showing an example of changes in wireless quality according to an embodiment of the present invention, for a car traveling downhill and uphill; FIG. 2 is a block diagram showing an example of a configuration for estimating an absolute position of a car according to an embodiment of the present invention. 10 is a flowchart showing an example of a process for acquiring a movement start time and a movement stop time of a car according to an embodiment of the present invention. 10 is a flowchart showing an example of a process for calculating a travel distance and a number of floors traveled from a car's travel start time and travel stop time according to an embodiment of the present invention. FIG. 11 is a diagram showing an example of converting a characteristic (a) of a cage's movement start time and movement stop time into a characteristic (b) of a movement distance according to an embodiment of the present invention. 10 is a flowchart showing an example of a process for estimating a moving direction based on wireless quality from a movement start time to a movement stop time of a car according to an embodiment of the present invention. 10 is a flowchart showing an example of a process for acquiring a correspondence between an absolute position of a car and a wireless quality according to an embodiment of the present invention. FIG. 4 is a diagram showing the changing state of the floor of the car according to one embodiment of the present invention.

Below, one embodiment of the present invention (hereinafter referred to as "this example") will be described with reference to the attached drawings.

[Overall system configuration]
FIG. 1 shows an overview of an elevator to which the mobile wireless control system of this embodiment is applied.
In this example, the elevator is configured such that a control device 100 is installed in a machine room located near the top end of the elevator shaft (not shown), and the control device 100 performs wireless communication with a car 200 traveling in the elevator shaft.

Four antennas 121-124 are installed on the control device 100 side as fixed antennas, and four antennas 221-224 are installed on the car 200 as moving body antennas. The four antennas 121-124 connected to the control device 100 are installed at the top of the elevator shaft. The four antennas 221-224 installed on the car 200 are disposed on the upper part of the car 200. An example of the arrangement of the four antennas 121-124, 221-224 on the fixed side and car side will be described later (FIG. 4).
With such a configuration for wireless transmission, wireless communication is performed between the control device 100 and the car 200. The control device 100 transmits door opening/closing instructions and display control information for the display to the car 200, and the car 200 transmits button operation information and the like to the control device 100.

FIG. 2 shows a specific configuration for wireless communication between the control device 100 and the car 200.
The control device 100 is equipped with an elevator control unit 101, a radio signal control unit 102, and four radio devices 111 to 114. The car 200 is equipped with a car control unit 201, a radio signal control unit 202, and four radio devices 211 to 214.

The elevator control unit 101 controls the running of the car 200. In controlling the running of the car 200, the elevator control unit 101 transmits and receives information to the car side control unit 201 in the car 200 and acquires necessary information. The car side control unit 201 transmits operation information of buttons inside the car and information necessary for running to the elevator control unit 101. Information that it is a door zone, which will be described later, is also transmitted from the car side control unit 201 to the elevator control unit 101.

The elevator control unit 101 sends transmission information to the four radio units 111 to 114 via the radio signal control unit 102, and wireless transmission is performed from the four antennas 121 to 124 connected to the radio units 111 to 114 to the four antennas 221 to 224 on the car side.
Furthermore, the four wireless devices 111-114 receive signals wirelessly transmitted from four antennas 221-224 connected to the four wireless devices 211-214 on the car side at the four antennas 121-124. The signals received by the four antennas 121-124 are then received and processed by the four wireless devices 111-114, and the resulting received information is supplied to the elevator control unit 101 via the wireless signal control unit 102.
The radio signal control unit 102 controls the radio communications in each of the radio devices 211 to 214 .

The four wireless devices 111-114 and 211-214 on the fixed and mobile sides are also referred to as the first wireless devices 111, 211, the second wireless devices 112, 212, the third wireless devices 113, 213, and the fourth wireless devices 114, 214, as shown in FIG. 2. In this example, the first wireless device 111 on the fixed side performs wireless communication with the first wireless device 211 on the car side, and the second wireless device 112 on the fixed side performs wireless communication with the second wireless device 212 on the car side. Similarly, the third wireless device 113 on the fixed side performs wireless communication with the third wireless device 213 on the car side, and the fourth wireless device 114 on the fixed side performs wireless communication with the fourth wireless device 214 on the car side. Therefore, in this example, four wireless transmission paths are formed, and the same information is transmitted to these four wireless transmission paths.

In the wireless transmission path of each system, wireless communication is performed by changing the transmission frequency. The frequency at which the fixed-side wireless devices 111-114 perform wireless communication is controlled by the wireless signal control unit 102 in the control device 100. The frequency at which the car-side wireless devices 211-214 perform wireless communication is controlled by the wireless signal control unit 202 in the car 200. The wireless signal control unit 202 in the car 200 sets the frequency at which wireless communication is performed according to instructions from the wireless signal control unit 102 in the control device 100. The configuration of the wireless transmission path of each system and the setting of the frequency will be described later with reference to FIG. 4.

[Hardware configuration of control unit]
FIG. 3 shows an example of a hardware configuration in the case where the radio signal control unit 102 is configured by a computer.

The wireless signal control unit 102 includes a CPU (Central Processing Unit) 102a, a main memory unit 102b, a non-volatile storage 102c, a network interface 102d, and an input/output unit 102e, each of which is connected to a bus.

The CPU 102a is an arithmetic processing unit that reads out and executes program code of software that realizes the functions performed by the radio signal control unit 102 from the main memory unit 102b or the non-volatile storage 102c. The main memory unit 102b stores the program code and is used as a work area for executing arithmetic processing.
The CPU 102a reads out program codes from the main memory 102b or the non-volatile storage 102c, and executes arithmetic processing in the work area of the main memory 102b. As a result, various processing function units are configured in the main memory 102b. For example, the main memory 102b is configured with a position acquisition unit 102f, a transmission quality collection unit 102g, and a combination setting unit 102h. The processing performed by the position acquisition unit 102f, the transmission quality collection unit 102g, and the combination setting unit 102h will be described later with reference to FIG. 7.

For example, a large-capacity information storage medium such as a hard disk drive (HDD), a solid state drive (SSD), or a memory card is used as the non-volatile storage 102c. The non-volatile storage 102c stores software that realizes the functions of the wireless signal control unit 102, data obtained by executing the program, and information as a database.

The network interface 102d may be, for example, a network interface card (NIC) or the like, and may transmit and receive data to and from other devices. For example, the network interface 102d may communicate with the elevator control unit 101.
The input/output unit 102e outputs information to be wirelessly transmitted to each of the wireless devices 111 to 114, and also receives information received by each of the wireless devices 111 to 114. The input/output unit 102e also outputs commands to control the transmission frequencies of each of the wireless devices 111 to 114.

Note that FIG. 3 shows a hardware configuration in which the wireless signal control unit 102 is configured as a computer, but some or all of the functions performed by the wireless signal control unit 102 may be realized by hardware such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit).

[Antenna placement and signal quality]
FIG. 4 shows an example of the arrangement of four antennas 121 to 124 on the fixed side, which is the control device 100 side, and four antennas 221 to 224 on the car 200 side.
In the example of FIG. 4, the four antennas 221 to 224 on the car 200 side are arranged at the four corners of the upper end of the housing that constitutes the car 200, spaced at a predetermined distance from each other.
The four antennas 121-124 on the fixed side are installed on the ceiling of the shaft through which the car 200 travels, and are spaced apart at the same distance as the four antennas 221-224 on the car 200 side. Therefore, each of the antennas 121-124 on the fixed side and each of the antennas 221-224 on the car 200 side are installed facing each other.

In this example, as shown in Figure 4, four wireless transmission paths Da, Db, Dc, and Dd are formed between the four antennas 121-124 on the fixed side and the four antennas 221-224 on the car side, and wireless communication is performed on each of the wireless transmission paths Da, Db, Dc, and Dd. Figure 4 shows a state in which wireless transmission is performed from the four antennas 221-224 on the car side to the four antennas 121-124 on the fixed side, but in reality wireless communication is performed in both directions.

The transmission frequencies for wireless communication over the four wireless transmission paths Da, Db, Dc, and Dd are set to different frequencies. As already explained, these frequencies are set under the control of the wireless signal control unit 102 on the fixed side, and the wireless signal control unit 202 on the car side is also set under instructions from the fixed side so that the same frequencies are used for each of the wireless transmission paths Da, Db, Dc, and Dd.

In Figure 4, W24, W52, W53, and W56 in parentheses for each wireless transmission path Da, Db, Dc, and Dd indicate that wireless transmission is performed using the 2.4 GHz band, 5.2 GHz band, 5.3 GHz band, and 5.6 GHz band, respectively. However, the combinations of the four wireless transmission paths Da, Db, Dc, and Dd and wireless transmission frequencies shown in Figure 4 are only examples, and the optimal frequency combinations to be used for each wireless transmission path Da, Db, Dc, and Dd are searched for and set, as described below.

The lengths of the wireless transmission paths Da, Db, Dc, and Dd change depending on the travel of the car 200. That is, when the car 200 is located on the top floor, the fixed-side antennas 121, 122, 123, and 124 are in close proximity to the car-side antennas 221, 222, 223, and 224, respectively. Then, as the car 200 descends from the top floor, the distance between the fixed-side antennas 121 to 124 and the car-side antennas 221 to 224 increases.

Fig. 5 shows the change in quality of signals transmitted through each of the wireless transmission paths Da, Db, Dc, and Dd depending on the distance from the ceiling of the elevator shaft of the car 200. The horizontal axis of Fig. 5 shows the distance from the ceiling of the elevator shaft of the car 200, and the vertical axis shows the signal quality. As the signal quality, for example, reception strength, an error occurrence rate of the received data, etc. can be applied.
The signal quality characteristics of the four transmission paths Da, Db, Dc, and Dd shown in Figure 5 indicate the signal quality characteristics over the entire range in which the cage 200 moves, but when the signal quality is acquired discretely, a smoothing process is performed to obtain continuous signal quality characteristics over the entire range as shown in Figure 5.

The signal quality is determined to be equal to or higher than a required signal quality TH1 that allows the receiving side to correctly receive the signal.
The signal quality characteristics of the four transmission paths Da, Db, Dc, and Dd shown in FIG. 5 decrease as the distance from the elevator shaft ceiling increases, but even on the lowest floor, the signal quality must be equal to or higher than the required signal quality TH1.

5, when wireless communication is performed using the wireless transmission path Dc at frequency W56, the quality is the lowest, and the difference from the required signal quality TH1 on the lowest floor is small, which indicates an unfavorable communication state. On the other hand, when wireless communication is performed using the wireless transmission path Da at frequency W24, the quality is the best, and the difference from the required signal quality TH1 on the lowest floor is relatively sufficient.
However, the example in FIG. 5 is one example of a combination of four transmission paths Da, Db, Dc, and Dd and four frequencies W24, W52, W53, and W56, and when other combinations are used, the characteristics shown in FIG. 5 will be different.

For example, the example of Fig. 6(a) shows a case where frequencies W24, W52, W53, and W56 are assigned to the four transmission paths Da, Db, Dc, and Dd, respectively, in the same order as in the case shown in Fig. 4. On the other hand, the example of Fig. 6(b) shows a case where frequencies W56, W53, W24, and W52 are assigned to the four transmission paths Da, Db, Dc, and Dd, respectively. In the case of the combination of Fig. 6(b), the signal quality characteristics are different from the case shown in Fig. 5.
In this example, the fixed-side radio signal control unit 102 collects the signal quality for each combination of radio frequencies on the four transmission paths Da, Db, Dc, and Dd, and performs a process of allocating the most appropriate frequency to the antennas of each transmission path Da, Db, Dc, and Dd.

When determining whether the signal quality is equal to or greater than the required signal quality TH1, instead of obtaining continuous signal quality characteristics over the entire range using smoothing processing as shown in Figure 5, it may be possible to determine whether the instantaneous value of the acquired signal quality is equal to or greater than the required signal quality TH1.

[Setting process of antenna and frequency combination]
7 is a flowchart showing a flow of the process of setting the optimum antenna and frequency performed by the fixed-side radio signal control unit 102. This setting process is executed by a position acquisition unit 102f, a transmission quality collection unit 102g, and a combination setting unit 102h provided in the radio signal control unit 102. Setting combinations of the transmission paths Da, Db, Dc, and Dd and frequencies means setting combinations of antennas and frequencies to be used for the transmission paths Da, Db, Dc, and Dd.

First, the wireless signal control unit 102 sets a certain combination of frequencies for the antennas for each transmission path Da, Db, Dc, and Dd, and then sends an instruction to the elevator control unit 101 to move the car 200 from the top floor to the bottom floor (step S11). At this time, the position acquisition unit 102f of the wireless signal control unit 102 performs a position acquisition process to acquire the car position, while the transmission quality collection unit 102g performs a transmission quality collection process to collect changes in signal quality. Note that an example of processing when the wireless signal control unit 102 cannot control the movement of the car 200 will be described in Figure 9 and subsequent figures.

After the car has completed moving from the top floor to the bottom floor, the combination setting unit 102h changes the combination of antennas and frequencies used for each of the transmission paths Da, Db, Dc, and Dd to another combination (step S12).
Then, the combination setting unit 102h judges whether the information on the required combination of antennas and frequencies has been collected by the transmission quality collecting unit 102g (step S13). In this example, since the combinations are four transmission paths Da, Db, Dc, and Dd and four frequencies, the combination setting unit 102h judges that the required information has been collected when at least four combinations in which four frequencies are set for each transmission path have been collected.

In step S13, if there is any information on an antenna and frequency combination that has not been collected (No in step S13), the wireless signal control unit 102 returns to step S11 and collects information on the movement of the cage 200 and changes in signal quality using another combination of antenna and frequency.
Then, if it is determined in step S13 that collection of information on combinations of antennas and frequencies has been completed (Yes in step S13), the combination setting unit 102h determines an appropriate combination of antennas and frequencies that satisfies the required signal quality (step S14).
Thereafter, the radio signal control unit 102 executes radio communication using the combination of antenna and frequency determined in step S14.

In addition, in step S14, if the optimal solution of the combination of an appropriate antenna and a frequency that satisfies the required signal quality cannot be obtained, the combination setting unit 102h issues an alarm indicating the corresponding situation to the elevator control unit 101. Upon receiving this alarm, the elevator control unit 101 notifies the department monitoring this elevator that the situation is such that the optimal solution of the combination of an appropriate antenna and a frequency that satisfies the required signal quality cannot be obtained.
By issuing an alarm when an optimal solution cannot be obtained in this way, it becomes possible to quickly take measures such as changing the placement of antennas when wireless communication cannot be performed properly due to frequency switching.

FIG. 8 is a sequence diagram showing the flow of processing performed by the wireless signal control unit 102 installed in the control device 100 on the machine room side and the wireless signal control unit 202 on the car side.
First, the wireless signal control unit 102 sets the antenna and frequency, captures a signal (elevator signal) wirelessly transmitted from the car 200, and measures the signal quality while estimating the car position (step S101).

Then, the radio signal control unit 102 determines that the car position has moved from the top floor to the bottom floor with the current antenna and frequency (step S102). After completing the process of step S102, the radio signal control unit 102 changes the combination of the antenna (radio transmission path) and the frequency (step S103).
When the radio signal control unit 102 changes the combination, information about the change in combination is wirelessly transmitted to the radio signal control unit 202 on the car side (step S104).
Then, the car-side radio signal control unit 202 changes the frequencies used by the car-side antennas 221 to 224 based on the received combination change information (step S105).
This process shown in FIG. 8 is repeated until the signal quality at all combinations of frequency changes has been collected.

[Process of acquiring correspondence between cage position and signal quality]
Fig. 9 is a flowchart showing the flow of the process in which the wireless signal control unit 102 acquires the correspondence between the car position and the signal quality. In the example described in Fig. 7, the wireless signal control unit 102 moves the car 200 from the top floor to the bottom floor, but there are cases in which the wireless signal control unit 102 cannot control the running of the car 200. In such cases, the wireless signal control unit 102 receives at least an elevator signal indicating the start or stop of the car's movement transmitted from the car 200 and estimates the position of the car 200 in the process shown in Fig. 9. Note that the elevator signal transmitted from the car 200 does not include floor information such as the floor on which the car 200 is stopped.

First, a case will be described in which the wireless signal control unit 102 can receive current floor information transmitted by the elevator control unit 101 to the car 200 in addition to elevator signals indicating start and stop of the car's movement transmitted from the car 200. To explain the process shown in the flowchart of Fig. 9, the wireless signal control unit 102 first acquires a door zone signal, which is a part of the elevator signal of the car 200, and acquires the start and stop times of the car 200's movement according to the flowchart of Fig. 15 described later, and further estimates the floor at which the car started to move and its time, and the floor at which the car stopped and its time from the current floor information transmitted by the elevator control unit 101 to the car 200 (step S21). Then, the wireless signal control unit 102 calculates the relationship between time and the car position from the movement characteristics of the elevator car 200 according to the flowchart of Fig. 16 described later (step S22).
Furthermore, the radio signal control unit 102 calculates the relationship between the cage position determined at each time and the signal quality at each time (step S23). This allows the correspondence relationship between the cage position and the signal quality described in Fig. 5 to be acquired, and makes it possible to determine which combination of antenna (radio transmission path) and frequency is appropriate.

FIG. 10 shows an example of estimating the floors at which the car 200 starts moving and the floors at which the car stops, based on the movement start time and the stop time of the car 200 in step S21 of the flow chart in FIG.
The vertical axis of FIG. 10 indicates the traveling speed of the car 200, and the horizontal axis indicates time.
As shown in FIG. 10, it is assumed that a travel history d11 in which the car 200 starts traveling and the speed decreases over a certain period of time, and a travel history d12 in which the speed decreases over an even longer period of time are acquired.

In this elevator example, the top floor is the 10th floor and the bottom floor is the 1st floor, the running history d12 is an example of a run from the 10th floor to the 1st floor, and the running history d11 is an example of a run from the 1st floor to the 5th floor. Using the signal quality acquired during these running histories d11 and d12, the correspondence between the cage position and the signal quality is obtained in step S23 of Figure 9.
In actuality, as shown in Fig. 12, the running history includes a running history d21 of a movement of five floors and a running history d22 of a movement of ten floors, which occur in sequence within a single time flow. Fig. 10 shows the running histories d21 and d22 overlapped together to form running histories d11 and d12 with the same start time. As shown in Fig. 12, in step S21 of Fig. 9, the start and stop of running of the car 200 can be determined from the elevator signal indicating that the car has left the door zone of the departure floor and entered the door zone of the stop floor.

On the other hand, if the elevator control unit 101 cannot receive the current floor information transmitted to the car 200, the travel history d11 shown in FIG. 10 corresponds to travel up to the 5th floor, and various travel patterns are assumed, such as travel from the 1st to the 5th floor or travel from the 6th to the 10th floor. If information on the departure floor and stop floors can be obtained, part of the correspondence between the car position and the signal quality can be obtained from this travel history d11, but the car position is unknown as it is and cannot be used. The process of determining the departure floor and stop floor from the travel history in the case where there is no travel from the top floor to the bottom floor (or vice versa) and the current floor information transmitted to the car 200 by the elevator control unit 101 cannot be obtained will be described later.

[Process of selecting the optimal combination of antenna and frequency]
FIG. 11 is a flowchart showing the flow of processing in which the radio signal control unit 102 finally determines the allocation of antennas (radio transmission paths) and frequencies based on collected signal quality information.
First, the radio signal control unit 102 judges the cage position-signal quality information for all collected combinations of antennas and frequencies, and calculates the difference between the signal quality of each combination and the required signal quality TH (FIG. 5) (step S31).

Then, the radio signal control unit 102 extracts an antenna/frequency assignment that minimizes the difference from the assignments of each antenna and frequency (step S32). Next, the radio signal control unit 102 searches for an antenna/frequency assignment that maximizes the difference from the assignments of each antenna and frequency (step S33).

Then, the radio signal control unit 102 determines the antenna/frequency assignment that maximizes the difference found in step S33 as the final antenna and frequency assignment (step S34).

[Processing for determining cage position from door zone signal]
As explained above, if there is no running from the top floor to the bottom floor (or vice versa) and the current floor information transmitted by the elevator control unit 101 to the car 200 cannot be obtained, the signal quality of the entire running path cannot be obtained as it is.
FIG. 14 shows the configuration of a position acquisition section 102f in the wireless signal control section 102 for determining the absolute position of the car 200 from the door zone signal in this case.
The position acquisition unit 102f includes a wireless quality measurement unit 11, a door zone signal acquisition unit 12, a moving distance calculation unit 13, a wireless quality database 14, a moving direction estimation unit 15, a relative position information database 16, and an absolute position estimation unit 17. In the drawings, the database is abbreviated to DB.

The wireless quality measuring unit 11 acquires wireless signals received by the four wireless devices 111 to 114, and individually measures the wireless signal quality of each of the wireless devices 111 to 114. Information on the wireless signal quality measured by the wireless quality measuring unit 11 is stored in a wireless quality database 14. Note that the information on the wireless signal quality is supplemented with information on the time when the wireless signal was received.
The door zone signal acquisition unit 12 extracts the door zone signal from the wireless signals received by the wireless devices 111-114 based on the information of the door zone signal format, acquires the door zone signal, and acquires the movement start time and stop time of the car 200. The door zone signal is a signal that indicates that the car 200 is traveling in the hoistway and is located within a door zone where the car door can be opened.

The travel distance calculation unit 13 acquires the speed characteristics of the car 200 for each travel floor, calculates the travel distance of the car 200 , and stores information on the calculated travel distance in the relative position information database 16 .
The movement direction estimation unit 15 estimates the movement direction of the cage 200 from the changes in wireless signal quality stored in the wireless quality database 14 using the movement distance information stored in the relative position information database 16, and adds the movement direction to the movement distance information.
For example, when driving histories d11 and d12 as shown in FIG. 10 are obtained, the travel direction estimation unit 15 can determine whether the driving is an uphill or downhill drive by determining the change in signal quality.

Fig. 13 shows an example of determining whether the current travel is uphill or downhill. In Fig. 13, the vertical axis indicates signal quality (wireless quality), and the horizontal axis indicates time.
FIG. 13A shows an example of change in signal quality d31 during downhill driving.
In the case of signal quality d31 during downhill travel, the cage-side antenna gradually moves away from the fixed-side antenna, so the average D _down of signal quality d31 gradually decreases.
FIG. 13(b) shows an example of change in signal quality d32 during uphill travel.
In the case of signal quality d32 during uphill travel, the cage-side antenna gradually approaches the fixed-side antenna, so that the average D _UP of signal quality d32 gradually increases.
Therefore, when the travel direction estimation unit 15 detects a deterioration in signal quality as shown in Fig. 13(a), it determines that the current travel is downhill. Also, when the radio signal control unit 102 detects an increase in signal quality as shown in Fig. 13(b), it determines that the current travel is uphill.

The absolute position estimation unit 17 estimates the absolute position for the travel distance information stored in the relative position information database 16, and adds the wireless signal quality stored in the wireless quality database 14 to each absolute position to generate absolute position-wireless quality information.

FIG. 15 is a flowchart showing the process in which the door zone signal acquisition unit 12 acquires the movement start time and stop time of the car 200 based on the door zone signal.
First, the door zone signal acquisition unit 12 extracts the door zone signal contained in the wireless signal based on the door signal format (step S41).
Next, the door zone signal acquisition unit 12 judges whether or not the time from entering one door zone to leaving the door zone is equal to or greater than a preset threshold value (step S42). If the time from entering the door zone to leaving the door zone is not equal to or greater than the threshold value in step S42 (No in step S42), the door zone signal acquisition unit 12 judges that the car 200 has passed through the floor of the door zone without stopping, and ignores the corresponding door zone signal.

Then, in step S42, if the time from entering the door zone to leaving it is equal to or greater than the threshold (Yes in step S42), the door zone signal acquisition unit 12 sets the time of entering the door zone as the movement stop time of the car 200, and the time of leaving the door zone as the movement start time of the car 200 (step S43). The door zone signal acquisition unit 12 then supplies the obtained information on the movement start time and movement stop time to the movement distance calculation unit 13.

FIG. 16 is a flowchart showing the process in which the travel distance calculation unit 13 calculates the travel distance of the car 200.
First, the travel distance calculation unit 13 acquires information on the travel start time and travel stop time from the door zone signal acquisition unit 12, acquires the speed characteristics for each travel floor at that time from the elevator control unit 101, and extracts the speed characteristics corresponding to the time from the travel start to the stop (step S51). Then, the travel distance calculation unit 13 converts the speed characteristics into distance characteristics and acquires the travel distance and the number of travel floors (step S52). The travel distance calculation unit 13 adds the travel distance and the number of travel floors to the information on the travel start time and the travel stop time, and stores them in the relative position information database 16.

FIG. 17 shows an example of conversion from speed characteristics to distance characteristics performed by the travel distance calculation unit 13 in step S52.
Fig. 17(a) shows an example of the speed characteristic of the car 200. The vertical axis of Fig. 17(a) represents the speed at which the car 200 moves, and the horizontal axis represents time.
As shown in FIG. 17(a), the speed characteristic d41 of the car 200 is such that the speed gradually increases from the start of the car's movement, the car travels at a constant speed for a certain period of time, and then the speed gradually decreases and the car stops.

Fig. 17(b) shows a case where the speed characteristic d41 is converted into a travel distance d42. The vertical axis of Fig. 17(b) represents the travel distance of the car, and the horizontal axis represents time.
The speed characteristic d41 shown in Fig. 17(a) is integrated to convert it into the travel distance d42 shown in Fig. 17(b). In addition, when the travel distance d42 is obtained, the travel distance calculation unit 13 can also obtain information on the number of floors traveled, which indicates how many floors the user has traveled.

FIG. 18 is a flowchart showing a process in which the movement direction estimating unit 15 estimates the movement direction.
The movement direction estimating unit 15 acquires information on the movement start time and the movement stop time from the relative position information database 16, and also acquires information on the wireless quality from the movement start to the movement stop from the wireless quality database 14 (step S61).
Then, the moving direction estimating unit 15 linearly approximates the change in the acquired wireless quality and calculates the slope (step S62). Furthermore, the moving direction estimating unit 15 calculates an estimated value of the moving direction from the calculated slope (step S63).
Here, the estimation of the direction of movement is, for example, a state in which the wireless quality gradually decreases as shown in FIG. 13(a) as a downward movement, and a state in which the wireless quality gradually improves as shown in FIG. 13(b) as an upward movement.

FIG. 19 is a flowchart showing the process in which the absolute position estimation unit 17 estimates the absolute position of the car 200.
First, the absolute position estimation unit 17 extracts information on the distance traveled, the number of floors traveled, and the direction of travel, which are history information on the relative position stored in the relative position information database 16 (step S71).The absolute position estimation unit 17 then acquires floor information on the building in which the elevator is installed, and estimates which floors the extracted number of floors traveled to have the highest probability of being traveled to (step S72).The estimation in step S72 is performed, for example, by applying the Viterbi algorithm. The Viterbi algorithm will be described later.

The use of the Viterbi algorithm is just one example, and other methods may be used to estimate the number of floors to which the car 200 will move. For example, if it is possible to obtain the initial floor value when the car 200 starts moving, it is possible to estimate the number of floors to which the car has moved from the initial value. For example, when there have been no car calls for a certain period of time and the car 200 stops at the first floor and waits, the initial value may be set to the first floor.

Returning to the explanation of the flowchart in FIG. 19, the absolute position estimation unit 17 determines the travel route with the highest probability estimated in step S72 as the absolute position, which is travel floor information (step S73).
Thereafter, the absolute position estimation unit 17 calculates time-absolute position information indicating the absolute position of the car for each time based on the travel floor information determined in step S73, the travel start time stored in the relative position information database 16, and the speed characteristics for each travel floor (step S74).
Furthermore, the absolute position estimation unit 17 acquires the time-wireless quality information stored in the wireless quality database 14, and calculates absolute position-wireless quality information indicating the wireless quality for each absolute position (step S74). The absolute position estimation unit 17 calculates and outputs the absolute position-wireless quality information obtained in step S74 (step S75).

FIG. 20 shows the principle of the Viterbi algorithm for estimating from which floors the vehicle has moved to and from which floors in step S72.
In the Viterbi algorithm, past cage movements are accumulated for a certain period of time and then an estimation process is performed.
In the example of FIG. 20, an elevator that moves from the first floor to the fifth floor is assumed.
In the first stage, suppose there is a movement up two floors. At this time, the possible movements of the car are from the first floor to the third floor, from the second floor to the fourth floor, or from the third floor to the fifth floor.

Next, suppose that there is a move down three floors in the second stage. In this case, either a move from the 5th floor to the 2nd floor or a move from the 4th floor to the 1st floor is possible. Therefore, of the three candidates for the move in the first stage, a move from the 1st floor to the 3rd floor is excluded as a candidate.
Furthermore, suppose that in the third stage, there is a movement up one floor, and in the fourth stage, there is a movement up four floors.
As a result, the car position after the movement in the fourth stage is fixed to the fifth floor, and the absolute positions during each movement from the first stage to the fourth stage are determined.
In this way, by applying the Viterbi algorithm, it becomes possible to estimate the absolute position from the relative positions of the cages.

[Effects of the system according to this embodiment]
According to the system of this embodiment described above, when performing wireless transmission between the elevator car 200, which is a moving body, and the ceiling side of the elevator shaft, which is a fixed side, it is possible to set up multiple wireless transmission paths and properly measure the transmission quality when switching the frequency used in each wireless transmission path. Therefore, by applying the combination of frequencies that has the largest difference from the required signal quality based on the measured transmission quality, wireless transmission between the moving body and the fixed side can be performed with proper quality. Therefore, when installing the elevator, it is no longer necessary for the installer to manually search for an appropriate frequency, and it is possible to reduce the implementation process during the elevator installation work.
In particular, in the case of an elevator, the position of the car 200 of the moving body is known only at two discrete positions, the departure floor and the stop floor. According to this example, however, it is possible to estimate the transmission quality of the entire continuous range of movement from these limited discrete positions, and it becomes possible to apply the frequency combination that has the largest difference from the required signal quality.

When applying a combination of frequencies that has the largest difference from the required signal quality, it is preferable to estimate the transmission quality of the entire range in which a cage (mobile body) can move by smoothing processing as shown in Figure 5, and set a combination of frequencies that has the largest minimum value of the estimated transmission quality of the entire range compared to a predetermined required signal quality value.
Alternatively, when applying the combination of frequencies with the largest difference from the required signal quality, the combination of frequencies with the largest minimum instantaneous value of the transmission quality collected by the transmission quality collection unit 102g may be applied.
Normally, as explained in Fig. 5, the signal quality gradually decreases as the distance from the fixed side increases, and it is sufficient if the difference from the required signal quality at the most distant position is sufficient. However, in cases where the minimum value of the transmission quality temporarily decreases only when passing through a specific position due to the influence of structures within a building, etc., a combination that avoids the decrease in the minimum value of the instantaneous value may be used.

Moreover, the measurement of the transmission quality and the setting of the combination of frequencies used in each transmission path must be performed as an initial setting at least when the elevator, which is a moving object, is installed. Moreover, even after the elevator starts operating, it is preferable to measure the transmission quality and reset the combination of frequencies used in each transmission path as needed. For example, the measurement is performed at regular intervals, such as once a month, and the resetting is performed. Alternatively, the wireless signal quality may be checked as needed during operation, and if it is determined that the difference between the wireless signal quality and the threshold value is not sufficient, the transmission quality may be measured again and the combination of frequencies used in each transmission path may be reset. It is preferable to switch the frequency during times when the elevator is not used much, such as at night or on holidays.
By reconfiguring the device as needed in this way, even if the wireless environment of the building in which it is installed changes, the device will automatically switch to an appropriate setting for wireless communication, allowing for uninterrupted wireless communication.

[Modification]
It should be noted that the embodiment examples described so far have been described in detail in order to explain the present invention in an easily understandable manner, and are not necessarily limited to those having all of the configurations described.
For example, in the above-described embodiment, antennas 221-224 are arranged at the four corners of the upper part of car 200, and four antennas 121-124 are also arranged on the ceiling of the elevator shaft, which is the fixed side, to configure four wireless transmission paths. In contrast, at least two wireless transmission paths may be configured, and combinations of frequencies to be used in the two wireless transmission paths may be set. Alternatively, four or more antennas may be arranged on both the moving side and the fixed side, and more combinations may be set. In addition, in the four wireless transmission paths, four frequencies are combined, but the number of frequencies to be used may be greater than the number of wireless transmission paths, allowing more combinations to be applied.

In addition, in the above-described embodiment, the frequency is switched, but depending on the wireless transmission method, the transmission channel may be switched instead of the frequency. In the case of a wireless transmission method that switches the transmission channel, it is sufficient to measure the combination of the wireless transmission path and the transmission channel for each system and apply the appropriate combination.

Furthermore, in the above-described embodiment, antennas 221-224 are placed at the four corners of the top of car 200, and four antennas 121-124 are also placed on the ceiling of the elevator shaft, which is the fixed side. In contrast, an antenna may be placed at the bottom of car 200 and at the bottom of the elevator shaft. In this case, the wireless signal quality is likely to be lowest when car 200 is located at the top floor, which is the opposite of the change in signal quality described in the embodiment. It is preferable that the fixed side antenna is located near the location where the elevator control device is installed.

In addition, in the above-described embodiment, the setting of the transmission frequency and the transmission channel is changed by both the car-side radio and the fixed-side radio, but the setting of the transmission frequency and the transmission channel may be changed by only one of them.

In the above-described embodiment, the invention is applied to an elevator, in which wireless communication is performed between the mobile body and the fixed side. However, the invention may be applied to other mobile bodies, so long as wireless communication is performed between the mobile body moving along a predetermined route and the fixed side. For example, the invention may be applied to a case in which wireless communication is performed between a transport device moving along a predetermined route in a warehouse and the fixed side.

In addition, in the configuration diagrams shown in Figures 2, 3, and 14, only control lines and information lines that are considered necessary for explanation are shown, and not all control lines and information lines in the product are necessarily shown. In reality, it can be considered that almost all components are connected to each other.
Furthermore, when the system of this example is configured with an information processing device such as a computer, the program that realizes the mobile radio control system may be prepared in non-volatile storage or memory within the computer, or may be stored on a recording medium such as an external memory, an IC card, an SD card, or an optical disk, and then transferred.

11...wireless signal measurement unit, 12...door zone signal acquisition unit, 13...movement distance calculation unit, 14...wireless quality database, 15...movement direction estimation unit, 16...relative position information database, 17...absolute position estimation unit, 100...control device, 101...elevator control unit, 102...wireless signal control unit, 102a...CPU, 102b...main memory unit, 102c...non-volatile storage, 102d...network interface, 102e...input/output unit, 102f...position acquisition unit, 102g...transmission quality collection unit, 102h...setting unit, 111-114...wireless devices (first to fourth wireless devices), 121-124...antennas (fixed side), 201...car side control unit, 202...wireless signal control unit, 211-214...wireless devices (first to fourth wireless devices), 221-224...antennas (car side)

Claims (10)

N antennas (N is an integer of 2 or more) are installed on each of the mobile body and the fixed side,
A mobile radio control system in which N antennas of the mobile unit and the N antennas of the fixed unit are used to form N radio transmission paths for wireless communication, and communication is enabled by switching a transmission frequency or a transmission channel of the N radio transmission paths to a plurality of transmission frequencies or transmission channels,
a position acquisition unit that discretely acquires a moving position of the moving object;
a transmission quality collection unit that collects transmission quality during transmission at a plurality of prepared transmission frequencies or transmission channels in the N wireless transmission paths;
a combination setting unit that sets an optimal transmission frequency or transmission channel for the N wireless transmission paths based on the discrete movement positions of the moving body acquired by the position acquisition unit and the transmission quality of each transmission frequency or each transmission channel for each wireless transmission path collected by the transmission quality collection unit. The mobile radio control system according to claim 1 , wherein the combination setting unit sets an optimal transmission frequency or transmission channel for the N radio transmission paths based on the transmission quality collected by the transmission quality collecting unit and the discrete moving positions. 3. The mobile radio control system according to claim 2, wherein the combination setting unit estimates the transmission quality of the entire range in which the mobile body can move from the transmission quality collected by the transmission quality collecting unit and the discrete moving positions, and sets a transmission frequency or transmission channel at which the minimum value of the estimated transmission quality of the entire range is the largest from a predetermined required signal quality value. The mobile radio control system according to claim 2 , wherein the combination setting unit sets a transmission frequency or a transmission channel that maximizes a minimum value of the instantaneous values of the transmission quality collected by the transmission quality collecting unit from a predetermined required signal quality value. The moving object is an elevator car,
3. The mobile radio control system according to claim 2, wherein the discrete position information acquired by the position acquisition unit is information indicating an absolute position using information indicating that the car is within a door zone installed at the floor where the car will stop and information about the floor where the car will stop. The moving object is an elevator car,
the discrete position information acquired by the position acquisition unit is information of a relative position indicating that the car is within a door zone provided at each floor where the car stops,
The mobile radio control system according to claim 2 , wherein the position acquisition unit determines the absolute position of the car based on a history of detection of the relative position. 7. The mobile radio control system according to claim 6, wherein the position acquisition unit acquires an initial value of the floor at which the car will stop in addition to relative position information indicating that the car is within a door zone provided at each floor at which the car will stop, to determine the absolute position of the car. The mobile radio control system according to claim 1 , wherein, when an optimal solution for an optimal transmission frequency or transmission channel for the N radio transmission paths cannot be obtained, the combination setting unit issues an alarm indicating a corresponding situation. The moving object is an elevator car,
The N antennas of the moving body are arranged at separate positions on the upper or lower part of the car,
The mobile wireless control system according to any one of claims 1 to 8, wherein the N fixed-side antennas are arranged at positions separated from each other on the upper end side or the lower end side of the elevator shaft. N antennas (N is an integer of 2 or more) are installed on each of the mobile body and the fixed side,
A mobile radio control method for performing radio communication by forming N radio transmission paths by N antennas of the mobile body and N antennas of the fixed side, and enabling communication by switching a transmission frequency or a transmission channel of the N radio transmission paths to a plurality of transmission frequencies or transmission channels,
A position acquisition process for acquiring discrete moving positions of the moving object;
A transmission quality collection process for collecting transmission quality during transmission in the N wireless transmission paths at a plurality of prepared transmission frequencies or transmission channels;
a combination setting process for setting an optimal transmission frequency or transmission channel for the N wireless transmission paths based on the moving position of the moving body acquired in the position acquisition process and the transmission quality of each transmission frequency or each transmission channel for each wireless transmission path collected in the transmission quality collection process.

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