Mobile body wireless control system and mobile body wireless control method

Abstract

To provide a mobile radio control system that sets antennas, frequencies, or channels that can properly maintain radio communication quality even in an environment in which N antennas (where N is an integer equal to or greater than 2) are installed on each of a mobile body and a fixed unit, N systems of wireless transmission paths are formed while simultaneously switching is performed to perform wireless communication, and the position information of the mobile unit is discretely obtained.SOLUTION: In a radio transmission configuration of an elevator, a radio signal control unit 102 includes a position acquisition unit that discretely acquires the movement position of a mobile body, a transmission quality collection unit that collects transmission quality during transmission on 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 in the N systems of wireless transmission paths on the basis of the movement position of the mobile body acquired by the position acquisition unit and the transmission quality of each transmission frequency or each transmission channel on each wireless transmission path collected by the transmission quality collection unit.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a mobile body wireless control system and a mobile body wireless control method.

Background Art

[0002] Conventionally, between a moving body that moves along a fixed path such as an elevator car and an external control device, they were connected by a cable, and the moving body (car) and the external control device communicated with each other via the cable. For example, in the case of an elevator car, it is common to connect a cable called a tail cord under the car in the hoistway and communicate with a control device installed in a machine room or the like via the tail cord.

[0003] However, with the increase in the height of buildings and the like, the length of the tail cord has increased, and the maintenance cost of the tail cord has been increasing. Therefore, it has been proposed to perform wireless communication between a moving body such as an elevator car and the outside, eliminating the need for communication cables such as tail cords.

[0004] Here, since the position of a moving body such as an elevator car moves, the positional relationship with a fixed side such as a control device constantly changes, the wireless quality is not constant, and measures for performing good wireless communication are necessary.

[0005] Patent Document 1 describes a technique of associating position information obtained by a GPS (Global Positioning System) receiver installed in a moving body such as a construction machine with wireless communication quality information, and when the moving body communicates, performing wireless communication using a communication method suitable for each position.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In the case of a moving body moving in an environment where position information can be acquired, as described in Patent Document 1, it is possible to appropriately control the communication method using the position information. On the other hand, in the case of an elevator car, where the position during movement can only be acquired discretely, the optimal communication method cannot be determined, and cases where the communication method is not set appropriately occur. That is, in the case of an elevator car, the position of the car is detected when it is in the door zone near the stop position of each floor, but while it is running away from the door zone, the exact position is unknown, and even if the technology of Patent Document 1 is applied, the communication method may not be set appropriately.

[0008] An object of the present invention is to provide a mobile body wireless control system and a mobile body wireless control method capable of appropriately maintaining wireless communication quality even in an environment where position information can only be acquired discretely.

Means for Solving the Problems

[0009] To solve the above problems, for example, the configuration described in the claims is adopted. This application includes a plurality of means for solving the above problems. For example, N antennas (N is an integer of 2 or more) are installed on each of the mobile body and the fixed side, and N wireless transmission paths are formed by the N antennas of the mobile body and the N antennas of the fixed side to perform wireless communication. At the same time, the transmission frequency or transmission channel in the N wireless transmission paths is switched to a plurality of transmission frequencies or transmission channels respectively to enable communication, and it is applied to a mobile body wireless control system. And a mobile wireless control system according to an example of the present application includes a position acquisition unit that discretely acquires the moving position of a mobile body, a transmission quality collection unit that collects the transmission quality during transmission at a plurality of prepared transmission frequencies or transmission channels on N wireless transmission paths, and 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, a combination setting unit that sets an optimal transmission frequency or transmission channel on the N wireless transmission paths.

Advantages of the Invention

[0010] According to the present invention, even in a situation where the position of the mobile body can only be acquired discretely, it is possible to determine the optimal transmission frequency or transmission channel for each wireless transmission path, and wireless communication between the mobile body and the fixed side can be performed in an optimal state. Problems, configurations, and effects other than those described above will be clarified by the description of the following embodiments.

Brief Description of the Drawings

[0011]

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Best Mode for Carrying Out the Invention

[0012] Hereinafter, an exemplary embodiment of the present invention (hereinafter referred to as "this example") will be described with reference to the accompanying drawings.

[0013] [Overall Configuration of the System] FIG. 1 shows an overview of an elevator to which the mobile radio control system of this example is applied. In the elevator of this example, a control device 100 is installed in a machine room installed near the upper end of a hoistway (not shown), and the control device 100 is configured to perform wireless communication with a car 200 traveling in the hoistway.

[0014] On the control device 100 side, four antennas 121 to 124 as the fixed side are installed, and on the car 200, four antennas 221 to 224 as the mobile side are installed. The four antennas 121 to 124 connected to the control device 100 are installed at the top of the hoistway. Also, the four antennas 221 to 224 installed on the car 200 are arranged on the upper part of the car 200. Examples of the arrangement of the four antennas 121 to 124 and 221 to 224 on the fixed side and the car side will be described later (FIG. 4). In such a configuration for performing wireless transmission, wireless communication is performed between the control device 100 and the car 200. The control device 100 transmits to the car 200 instructions for opening and closing the door, display control information on the display, etc., and the car 200 transmits button operation information, etc., to the control device 100.

[0015] FIG. 2 shows a specific configuration for performing wireless communication between the control device 100 and the car 200. In the control device 100, an elevator control unit 101, a wireless signal control unit 102, and four radios 111 to 114 are installed. Also, in the car 200, a car control unit 201, a wireless signal control unit 202, and four radios 211 to 214 are installed.

[0016] The elevator control unit 101 controls the movement of the car 200. In controlling the movement of the car 200, the elevator control unit 101 transmits and receives information with the car-side control unit 201 in the car 200 to obtain necessary information. The car-side control unit 201 transmits operation information of the car buttons, information necessary for movement, etc. to the elevator control unit 101. Information indicating that it is a door zone to be described later is also transmitted from the car-side control unit 201 to the elevator control unit 101.

[0017] The elevator control unit 101 sends transmission information to the four radios 111 to 114 via the radio signal control unit 102, and performs wireless transmission from the four antennas 121 to 124 connected to the radios 111 to 114 to the four antennas 221 to 224 on the car side. Also, the four radios 111 to 114 receive signals wirelessly transmitted from the four antennas 221 to 224 connected to the four radios 211 to 214 on the car side with the four antennas 121 to 124. Then, the signals received by the four antennas 121 to 124, that is, the reception information obtained by reception processing by the four radios 111 to 114, is supplied to the elevator control unit 101 via the radio signal control unit 102. The radio signal control unit 102 controls wireless communication in each of the radios 211 to 214.

[0018] As shown in FIG. 2, the four radios 111 to 114 on the fixed side and the four radios 211 to 214 on the moving body side are also referred to as the first radio 111, 211, the second radio 112, 212, the third radio 113, 213, and the fourth radio 114, 214. In the case of this example, the first radio 111 on the fixed side performs wireless communication with the first radio 211 on the car side, and the second radio 112 on the fixed side performs wireless communication with the second radio 212 on the car side. Similarly, the third radio 113 on the fixed side performs wireless communication with the third radio 213 on the car side, and the fourth radio 114 on the fixed side performs wireless communication with the fourth radio 214 on the car side. Therefore, in the case of this example, four wireless transmission paths are formed, and the same information is transmitted on these four wireless transmission paths.

[0019] In the wireless transmission paths of each system, wireless communication is performed by changing the transmission frequency. The frequencies at which the fixed-side radios 111 to 114 perform wireless communication are controlled by the wireless signal control unit 102 in the control device 100. The frequencies at which the car-side radios 211 to 214 perform wireless communication are 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 for performing wireless communication according to an instruction from the wireless signal control unit 102 in the control device 100. The configuration of the wireless transmission paths of each system and the setting of the frequencies will be described later with reference to FIG. 4.

[0020] [Hardware Configuration of the Control Unit] FIG. 3 shows an example of the hardware configuration when the wireless signal control unit 102 is configured by a computer.

[0021] 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, which are respectively connected to a bus.

[0022] The CPU 102a is an arithmetic processing unit that reads and executes the program code of software that realizes the functions performed by the wireless 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 the program code from the main memory unit 102b or the non-volatile storage 102c and executes arithmetic processing in the work area of the main memory unit 102b. As a result, various processing function units are configured in the main memory unit 102b. For example, a position acquisition unit 102f, a transmission quality collection unit 102g, and a combination setting unit 102h are configured in the main memory unit 102b. The processing performed by these position acquisition unit 102f, transmission quality collection unit 102g, and combination setting unit 102h will be described later with reference to FIG. 7.

[0023] For the non-volatile storage 102c, for example, a large-capacity information storage medium such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), or a memory card is used. 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.

[0024] For the network interface 102d, for example, a NIC (Network Interface Card) or the like is used, and data is transmitted and received with other devices. For example, the network interface 102d communicates 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 information received by each of the wireless devices 111 to 114 is input. Further, the input / output unit 102e outputs a command for controlling the transmission frequencies of each of the wireless devices 111 to 114.

[0025] Note that in FIG. 3, the hardware configuration in the case where the wireless signal control unit 102 is configured by a computer is shown, but part 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).

[0026] [Antenna Arrangement and Signal Quality] FIG. 4 shows an example of the arrangement of the four antennas 121 to 124 on the fixed side, which is the control device 100 side, and the 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 four corners of the upper end of the housing constituting the car 200 with a predetermined distance therebetween. The four antennas 121 to 124 on the fixed side are installed on the ceiling of the shaft where the cage 200 travels, and are arranged at the same distance as the four antennas 221 to 224 on the cage 200 side. Therefore, each of the antennas 121 to 124 on the fixed side and each of the antennas 221 to 224 on the cage 200 side are installed facing each other.

[0027] In the case of this example, as shown in FIG. 4, four wireless transmission paths Da, Db, Dc, and Dd are formed between the four antennas 121 to 124 on the fixed side and the four antennas 221 to 224 on the cage side, and wireless communication is performed through each of the wireless transmission paths Da, Db, Dc, and Dd. FIG. 4 shows a state where wireless transmission is performed from the four antennas 221 to 224 on the cage side to the four antennas 121 to 124 on the fixed side, but actually wireless communication is performed bidirectionally.

[0028] And the transmission frequencies when performing wireless communication through the four wireless transmission paths Da, Db, Dc, and Dd are set to different frequencies respectively. This frequency setting is performed under the control of the wireless signal control unit 102 on the fixed side as already described, and for the wireless signal control unit 202 on the cage side, it is also set to the same frequency for each of the wireless transmission paths Da, Db, Dc, and Dd according to the instruction from the fixed side.

[0029] W24, W52, W53, and W56 shown in parentheses for each of the wireless transmission paths Da, Db, Dc, and Dd in FIG. 4 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 combination of the four wireless transmission paths Da, Db, Dc, and Dd and the wireless transmission frequencies shown in FIG. 4 is an example, and as will be described later, the optimal combination of frequencies used for each of the wireless transmission paths Da, Db, Dc, and Dd is searched and set.

[0030] The lengths of the wireless transmission paths Da, Db, Dc, and Dd change as the car 200 travels. That is, when the car 200 is located on the top floor, the fixed-side antennas 121, 122, 123, and 124 are in a state of being close to the car-side antennas 221, 222, 223, and 224, respectively. Then, as the car 200 descends from the top floor, the distances between the fixed-side antennas 121 to 124 and the car-side antennas 221 to 224 increase.

[0031] FIG. 5 shows changes in the quality of signals transmitted through the respective wireless transmission paths Da, Db, Dc, and Dd depending on the distance from the ceiling of the hoistway of the car 200. The horizontal axis in FIG. 5 indicates the distance from the ceiling of the hoistway of the car 200, and the vertical axis indicates the signal quality. As the signal quality, for example, the reception intensity, the error occurrence rate of the received data, etc. are applicable. The signal quality characteristics of the four transmission paths Da, Db, Dc, and Dd shown in this FIG. 5 indicate the signal quality characteristics over the entire range in which the car 200 moves. However, when the signal quality is obtained discretely, a smoothing process is performed to obtain continuous signal quality characteristics over the entire range as shown in FIG. 5.

[0032] Regarding the signal quality, it is determined that it should be equal to or higher than the required signal quality TH1 at which the signal can be correctly acquired on the receiving side. The signal quality characteristics of the four transmission paths Da, Db, Dc, and Dd shown in FIG. 5 decrease as the distance from the hoistway ceiling increases, but it is necessary that they are equal to or higher than the required signal quality TH1 even at the bottom floor.

[0033] In the example of FIG. 5, it can be seen that when wireless communication is performed at frequency W56 using the wireless transmission path Dc, the quality is the lowest, and the difference from the required signal quality TH1 at the bottom floor is slight, indicating an unfavorable communication state. On the other hand, when wireless communication is performed at frequency W24 using the wireless transmission path Da, it can be seen that the quality is the best, and the difference from the required signal quality TH1 at the bottom floor is relatively well ensured. However, the example in FIG. 5 is an example of the combination of the four transmission paths Da, Db, Dc, Dd and the four frequencies W24, W52, W53, W56. When other combinations are used, FIG. 5 will have different characteristics.

[0034] For example, the example in FIG. 6(a) shows the case where the frequencies W24, W52, W53, W56 are respectively assigned to the four transmission paths Da, Db, Dc, Dd in order, similar to the case shown in FIG. 4. On the other hand, the example in FIG. 6(b) shows the case where the frequencies W56, W53, W24, W52 are respectively assigned to the four transmission paths Da, Db, Dc, Dd in order. In the case of the combination in FIG. 6(b), the characteristics of the signal quality are different from those shown in FIG. 5. In this example, the fixed-side wireless signal control unit 102 collects the signal quality in each combination of the four transmission paths Da, Db, Dc, Dd at each radio frequency, and performs the allocation process of the most appropriate frequency to the antennas of each transmission path Da, Db, Dc, Dd.

[0035] When determining whether the required signal quality is above TH1, instead of obtaining the continuous signal quality characteristics in the whole range by the smoothing process as shown in FIG. 5, it may be determined whether the instantaneous value of the obtained signal quality is above the required signal quality TH1.

[0036] [Setting Process of Antenna and Frequency Combination] FIG. 7 is a flowchart showing the process of the fixed-side wireless signal control unit 102 performing the optimal antenna and frequency setting process. This setting process is executed by the position acquisition unit 102f, the transmission quality collection unit 102g, and the combination setting unit 102h prepared in the wireless signal control unit 102. Note that setting the combination of the transmission paths Da, Db, Dc, Dd and the frequency means setting the combination of the antenna and the frequency used as the transmission paths Da, Db, Dc, Dd.

[0037] First, the wireless signal control unit 102 sets a certain combination of frequencies for the antennas for each transmission path Da, Db, Dc, 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, while the position acquisition unit 102f of the wireless signal control unit 102 performs position acquisition processing to acquire the car position, the transmission quality collection unit 102g performs transmission quality collection processing to collect changes in signal quality. Note that an example of the processing when the wireless signal control unit 102 cannot control the movement of the car 200 will be described after FIG. 9.

[0038] Then, after the car movement from the top floor to the bottom floor is completed, the combination setting unit 102h changes the combination of the antennas and frequencies used for each transmission path Da, Db, Dc, Dd to another one (step S12). Then, the combination setting unit 102h determines whether the information on the combination of the necessary antennas and frequencies could be collected by the transmission quality collection unit 102g (step S13). In the case of this example, since there are combinations of 4 transmission paths Da, Db, Dc, Dd and 4 frequencies, the combination setting unit 102h determines that the necessary information has been collected when at least 4 types of combinations in which 4 frequencies are set for each transmission path can be collected.

[0039] In step S13, if there is uncollected information on the combination of the antennas and frequencies (No in step S13), the wireless signal control unit 102 returns to step S11 and executes the movement of the car 200 and the collection of changes in signal quality with another combination of antennas and frequencies. Then, in step S13, when it is determined that the collection of the information on the combination of the antennas and frequencies is 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). With the combination of the antennas and frequencies determined in this step S14, the wireless signal control unit 102 will perform wireless communication hereafter.

[0040] In step S14, if the combination setting unit 102h fails to obtain an optimal solution for the combination of an appropriate antenna and frequency that satisfies the required signal quality, it 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 an optimal solution for the combination of an appropriate antenna and frequency that satisfies the required signal quality cannot be obtained. By issuing an alarm when the optimal solution cannot be obtained in this way, when wireless communication cannot be properly performed by switching the frequency, countermeasures such as changing the antenna arrangement can be quickly taken.

[0041] FIG. 8 is a sequence diagram showing the processing flow 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, after setting the antenna and frequency, the wireless signal control unit 102 captures a signal (elevator signal) wirelessly transmitted from the car 200 and measures the signal quality while estimating the car position (step S101).

[0042] Then, the wireless 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). When the processing in step S102 is completed, the wireless signal control unit 102 changes the combination of the antenna (wireless transmission path) and frequency (step S103). When there is a combination change in the wireless signal control unit 102, the information on the combination change is wirelessly transmitted to the wireless signal control unit 202 on the car side (step S104). Then, the wireless signal control unit 202 on the car side changes the frequencies used by the antennas 221 to 224 on the car side based on the received combination change information (step S105). The processing shown in FIG. 8 is repeated until the signal quality for all combinations of frequency changes is collected.

[0043] [Processing for obtaining the correspondence between car position and signal quality] FIG. 9 is a flowchart showing the flow of a process in which the wireless signal control unit 102 acquires the correspondence relationship between the car position and the signal quality. In the example described with reference to FIG. 7, it was assumed that the wireless signal control unit 102 moved the car 200 from the top floor to the bottom floor. However, there may be cases where the wireless signal control unit 102 cannot control the travel of the car 200. In such a case, the wireless signal control unit 102 estimates the position of the car 200 by receiving at least an elevator signal indicating the start or stop of the movement of the car transmitted from the car 200 in the process shown in FIG. 9. Note that the elevator signal transmitted from the car 200 does not include information such as the floor on which the car 200 has stopped.

[0044] First, a case will be described in which the wireless signal control unit 102 can receive, in addition to the elevator signal indicating the start or stop of the movement of the car transmitted from the car 200, the current floor information that the elevator control unit 101 transmits to the car 200. Describing the process shown in the flowchart of FIG. 9, first, the wireless signal control unit 102 acquires a door zone signal, which is a part of the elevator signal of the car 200, in accordance with the flowchart of FIG. 15 described later, and acquires the start time and stop time of the movement of the car 200. Further, from the current floor information that the elevator control unit 101 transmits to the car 200, the floor and the time at which the movement started and the floor and the time at which the movement stopped are estimated (step S21). Then, the wireless signal control unit 102 calculates the relationship between the time and the car position from the movement characteristics of the elevator car 200 in accordance with the flowchart of FIG. 16 described later (step S22). Furthermore, the wireless signal control unit 102 calculates the relationship between the car position determined at each time and the signal quality at each time (step S23). Thereby, the correspondence relationship between the car position and the signal quality described in FIG. 5 is acquired, and it becomes possible to determine which combination of the antenna (wireless transmission path) and the frequency is appropriate.

[0045] FIG. 10 shows an example of estimating the floor at which the movement started and the floor at which the movement stopped from the start time and stop time of the movement of the car 200 in step S21 of the flowchart of FIG. 9. The vertical axis in FIG. 10 indicates the running speed of the car 200, and the horizontal axis indicates time. As shown in FIG. 10, assume that the car 200 starts running, and a running history d11 in which the speed decreases in a certain period of time and a running history d12 in which the speed decreases in a longer period of time are acquired.

[0046] In the elevator of this example, the top floor is the 10th floor and the bottom floor is the 1st floor. The running history d12 is an example of running from the 10th floor to the 1st floor, and the running history d11 is an example of running from the 1st floor to the 5th floor. Using the signal quality acquired during these running histories d11 and d12, the correspondence between the car position and the signal quality is obtained in step S23 of FIG. 9. Note that, as actually shown in FIG. 12, in the flow of one time, a running history d21 of moving for five floors and a running history d22 of moving for ten floors occur in sequence in the running history. FIG. 10 shows the running histories d11 and d12 obtained by overlapping these respective running histories d21 and d22 with the start times being the same time. As shown in FIG. 12, in step S21 of FIG. 9, the start and stop of the running of the car 200 can be determined from the elevator signal indicating that it has exited the door zone of the departure floor and entered the door zone of the stop floor.

[0047] On the other hand, when the elevator control unit 101 cannot receive the current floor information transmitted to the car 200, for the running history d11 shown in FIG. 10, it corresponds to running up to the 5th floor. Various running patterns are assumed, such as running from the 1st floor to the 5th floor or running from the 6th floor to the 10th floor. When the information of the departure floor and the stop floor can be acquired, a part of the correspondence between the car position and the signal quality can be obtained from this running history d11, but the car position is unknown as it is and cannot be used. The determination process of the departure floor and the stop floor from the running history in the case where 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 acquired will be described later.

[0048] [Process of selecting the optimal combination of antenna and frequency] FIG. 11 is a flowchart showing the process in which the wireless signal control unit 102 finally determines the allocation of antennas (radio transmission paths) and frequencies from the collected signal quality information. First, the wireless signal control unit 102 determines the car position-signal quality information for all combinations of the collected antennas and frequencies, and calculates the difference from the required signal quality TH (FIG. 5) for the signal quality of each combination (step S31).

[0049] Then, the wireless signal control unit 102 extracts the antenna / frequency allocation with the minimum difference from each antenna and frequency allocation (step S32). Subsequently, the wireless signal control unit 102 searches for the antenna / frequency allocation with the maximum difference from each antenna and frequency allocation (step S33).

[0050] Thereafter, the wireless signal control unit 102 determines the antenna / frequency allocation with the maximum difference, which was searched in step S33, as the final antenna and frequency allocation (step S34).

[0051] [Process of determining the car position from the door zone signal] As described above, when there is no running from the top floor to the bottom floor (or vice versa), and the current floor information that the elevator control unit 101 transmits to the car 200 cannot be obtained, the signal quality of all running paths cannot be obtained as it is. FIG. 14 shows the configuration of the position acquisition unit 102f in the wireless signal control unit 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 as DB.

[0052] The wireless quality measurement unit 11 acquires the 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. The information on the wireless signal quality measured by the wireless quality measurement unit 11 is stored in the wireless quality database 14. Note that the information on the wireless signal quality has the information on the time when the wireless signal was received added thereto. The door zone signal acquisition unit 12 extracts the door zone signal from the wireless signals received by the wireless devices 111 to 114 based on the information on the door zone signal format, acquires the door zone signal, and acquires the start time and stop time of the movement of the car 200. The door zone signal is a signal indicating that the car 200 is located within the door zone where it is possible to open the car door while traveling on the hoistway.

[0053] The movement distance calculation unit 13 acquires the speed characteristics of the car 200 for each moving floor, calculates the movement distance of the car 200, and stores the information on the calculated movement distance in the relative position information database 16. The movement direction estimation unit 15 estimates the movement direction of the car 200 from the change in the wireless signal quality stored in the wireless quality database 14 with respect to the information on the movement distance stored in the relative position information database 16, and adds the movement direction to the information on the movement distance. For example, when the travel histories d11 and d12 as shown in FIG. 10 are obtained, the movement direction estimation unit 15 can determine whether the travel is an upward travel or a downward travel by determining the change in the signal quality.

[0054] FIG. 13 shows an example of determining whether this travel is upward or downward. The vertical axis in FIG. 13 indicates the signal quality (wireless quality), and the horizontal axis indicates the time. FIG. 13(a) shows an example of the change in the signal quality d31 during a downward travel. In the case of the signal quality d31 during a downward travel, since the antenna on the car side gradually moves away from the fixed-side antenna, the average D of the signal quality d31 down gradually decreases. FIG. 13(b) shows an example of the change in the signal quality d32 during an upward travel. In the case of the signal quality d32 during upward travel, since the car body side antenna gradually approaches the fixed side antenna, the average D of the signal quality d32 UP gradually increases. Therefore, when the moving direction estimation unit 15 detects a decrease in signal quality as shown in Fig. 13(a), it determines that the travel at that time is downward travel. Further, when the wireless signal control unit 102 detects an increase in signal quality as shown in Fig. 13(b), it determines that the travel at that time is upward travel.

[0055] The absolute position estimation unit 17 estimates the absolute position of the movement 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 obtain absolute position - wireless quality information.

[0056] 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 body 200 based on the door zone signal. First, the door zone signal acquisition unit 12 extracts the door zone signal included in the wireless signal based on the door signal format (step S41). Next, the door zone signal acquisition unit 12 determines whether the time from entering one door zone to exiting the door zone is equal to or greater than a preset threshold value (step S42). In step S42, if the time from entering the door zone to exiting is less than the threshold value (No in step S42), the door zone signal acquisition unit 12 determines that the car body 200 has passed through the floor of the corresponding door zone without stopping, and ignores the corresponding door zone signal.

[0057] Then, in step S42, if the time from entering the door zone to exiting is equal to or greater than the threshold value (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 body 200, and sets the time of exiting the door zone as the movement start time of the car body 200 (step S43). Then, the door zone signal acquisition unit 12 supplies the obtained movement start time and movement stop time information to the movement distance calculation unit 13.

[0058] FIG. 16 is a flowchart showing the process in which the moving distance calculation unit 13 calculates the moving distance of the car 200. First, the moving distance calculation unit 13 acquires information on the start time and stop time of movement from the door zone signal acquisition unit 12, and also acquires the speed characteristics for each moving floor at that time from the elevator control unit 101, and extracts the speed characteristics corresponding to the time from the start to the stop of movement (step S51). Then, the moving distance calculation unit 13 converts the speed characteristics into distance characteristics, and acquires the moving distance and the number of moving floors (step S52). The moving distance calculation unit 13 adds the moving distance and the number of moving floors to the information on the start time and stop time of movement, and stores them in the relative position information database 16.

[0059] FIG. 17 shows an example of the conversion from speed characteristics to distance characteristics performed by the moving distance calculation unit 13 in step S52. FIG. 17(a) shows an example of the speed characteristics of the car 200. The vertical axis in FIG. 17(a) is the speed at which the car 200 moves, and the horizontal axis is time. As shown in FIG. 17(a), the speed characteristic d41 of the car 200 gradually increases in speed from the start of movement of the car, travels at a constant speed for a certain period of time, and then gradually decreases in speed and stops.

[0060] FIG. 17(b) shows the case where the speed characteristic d41 is converted into the moving distance d42. The vertical axis in FIG. 17(b) is the moving distance of the car, and the horizontal axis is time. By integrating the speed characteristic d41 shown in FIG. 17(a), it is converted into the moving distance d42 shown in FIG. 17(b). Also, when the moving distance d42 is obtained, the moving distance calculation unit 13 can also obtain information on the number of floors moved, which indicates how many floors have been moved.

[0061] FIG. 18 is a flowchart showing the process in which the moving direction estimation unit 15 estimates the moving direction. The moving direction estimation unit 15 acquires information on the start time and stop time of movement from the relative position information database 16, and also acquires information on the radio quality from the start to the stop of that movement from the radio quality database 14 (step S61). Then, the moving direction estimation unit 15 linearly approximates the change in the acquired radio quality and calculates the slope for the acquired radio quality (step S62). Further, the moving direction estimation unit 15 calculates an estimated value of the moving direction from the calculated slope (step S63). Here, for the estimation of the moving direction, for example, a state where the radio quality gradually decreases as shown in FIG. 13(a) is regarded as moving downward, and a state where the radio quality gradually increases as shown in FIG. 13(b) is regarded as moving upward.

[0062] 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 the information on the moving distance, the moving floor number, and the moving direction, which is the history information of the relative position stored in the relative position information database 16 (step S71). Then, the absolute position estimation unit 17 acquires the floor information of the building in which the elevator is installed and estimates which floors the extracted moving floor number has the highest probability of moving from and to (step S72). In the estimation in step S72, for example, the Viterbi algorithm is applied for estimation. The Viterbi algorithm will be described later.

[0063] Using the Viterbi algorithm is just an example, and the moving floor number may be estimated by other methods. For example, when the initial floor value when the car 200 starts moving can be obtained, it may be estimated from which floors to which floors the moving floor number from the initial value is. As the initial value, for example, when the car call does not continue for a certain period of time and the car 200 stops and waits on the first floor, the initial value can be set to the first floor.

[0064] Returning to the description of the flowchart in FIG. 19, the absolute position estimation unit 17 determines the moving path with the highest probability estimated in step S72 as the absolute position, which is the moving floor information (step S73). After that, based on the moving floor information determined in step S73, the start time of movement stored in the relative position information database 16, and the speed characteristics for each floor, the absolute position estimation unit 17 calculates time-absolute position information indicating the absolute position of the car at each time (step S74). Furthermore, the absolute position estimation unit 17 acquires the time-radio quality information stored in the radio quality database 14 and calculates absolute position-radio quality information indicating the radio quality for each absolute position (step S74). The absolute position estimation unit 17 calculates and outputs the absolute position-radio quality information obtained in step S74 (step S75).

[0065] Figure 20 shows the principle of the Viterbi algorithm for estimating from which floor to which floor the elevator has moved based on the number of floors moved in step S72. In the Viterbi algorithm, the past movements of the car are accumulated for a certain period, and then the estimation process is performed. In the example of Figure 20, an elevator moving from the 1st floor to the 5th floor is assumed. And in the first stage, assume there is a movement where the elevator goes up two floors. At this time, the possible movements of the car are any one of the movements from the 1st floor to the 3rd floor, from the 2nd floor to the 4th floor, and from the 3rd floor to the 5th floor.

[0066] Next, as the movement in the second stage, assume there is a movement where the elevator goes down three floors. In this case, either a movement from the 5th floor to the 2nd floor or a movement from the 4th floor to the 1st floor is considered. Therefore, among the three candidates for the movement in the first stage, the movement from the 1st floor to the 3rd floor is excluded from the candidates. Furthermore, as the movement in the third stage, assume there is a movement where the elevator goes up one floor, and as the movement in the fourth stage, assume there is a movement where the elevator goes up four floors. As a result, the car position after the movement in the fourth stage is determined to be the 5th floor, and the absolute position at each movement from the first stage to the fourth stage is determined. In this way, by applying the Viterbi algorithm, it becomes possible to estimate the absolute position from the relative position of the car.

[0067] [Effects of the System of this Embodiment Example] According to the system of the present example described above, when performing wireless transmission between the car 200 of the elevator, which is a moving body, and the ceiling side of the hoistway, which is the fixed side, a plurality of wireless transmission paths are set, and the transmission quality when switching the frequencies used in each wireless transmission path can be properly measured. Therefore, based on the measured transmission quality, by applying the combination of frequencies with the largest difference from the required signal quality, wireless transmission between the moving body and the fixed side can be performed with appropriate quality. Therefore, when installing the elevator, it becomes unnecessary for the installer to manually search for an appropriate frequency, and the implementation process during the elevator installation work can be reduced. Particularly in the case of an elevator, although the position of the car 200, which is a moving body, is only known at two discrete positions, the starting floor and the stopping floor, according to the present example, it is possible to estimate the transmission quality of the entire continuous moving range from the limited discrete positions, and apply the combination of frequencies with the largest difference from the required signal quality.

[0068] When applying the combination of frequencies with the largest difference from the required signal quality, for example, it is preferable to estimate the transmission quality of the entire range where the car (moving body) can move by smoothing processing as shown in FIG. 5, and set the combination of frequencies for which the minimum value of the estimated transmission quality of the entire range is the largest from the 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 for which the minimum value of the instantaneous value of the transmission quality collected by the transmission quality collection unit 102g is the largest from the predetermined required signal quality value may be applied. Normally, as described with reference to FIG. 5, as the distance from the fixed side increases, the signal quality gradually decreases, and it is sufficient that there is a sufficient difference from the required signal quality at the position farthest away. However, in the case where the minimum value of the transmission quality temporarily decreases only when passing through a specific position due to the influence of structures in the building, etc., it may be a combination that avoids the decrease in the minimum value of the instantaneous value.

[0069] In addition, the measurement of transmission quality and the setting of the combination of frequencies used for each transmission path need to be initially set at least when installing the elevator, which is a mobile body. Also, after starting the operation of the elevator, it is preferable to measure the transmission quality and re-set the combination of frequencies used for each transmission path at any time. For example, measurements are taken at regular intervals such as once a month for re-setting. Alternatively, during operation, the wireless signal quality can be checked at any time, and when it is determined that the difference between the wireless signal quality and the threshold value is not sufficient, the transmission quality can be measured again and the combination of frequencies used for each transmission path can be re-set. The frequency switching is preferably performed during time periods when the elevator is less used, such as at night or on holidays. By performing such re-setting at any time, even when the wireless environment of the installed building changes, it can automatically switch appropriately for wireless communication and continue to enable wireless communication.

[0070] [Modification Example] Note that the embodiments described so far have been described in detail for easy understanding of the present invention and are not necessarily limited to those having all the configurations described. For example, in the above-described embodiment, antennas 221 to 224 are arranged at the four upper corners of the car 200, and four antennas 121 to 124 are also arranged on the ceiling of the hoistway, which is the fixed side, to form four wireless transmission paths. In contrast, at least two wireless transmission paths may be configured, and the combination of frequencies used for 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 to perform more combinations of settings. Also, in the four wireless transmission paths, four frequencies are combined, but the number of frequencies used may be more than the number of wireless transmission paths so that more combinations can be applied.

[0071] In the above-described embodiment, the frequency is switched. However, depending on the wireless transmission method, instead of switching the frequency, the transmission channel may be switched. In the case of a wireless transmission method that switches the transmission channel, the combination of the wireless transmission path and the transmission channel for each system may be measured and an appropriate combination may be applied.

[0072] Furthermore, in the above-described embodiment, antennas 221 to 224 are arranged at the four upper corners of the car 200, and four antennas 121 to 124 are also arranged on the ceiling of the hoistway on the fixed side. On the other hand, antennas may be arranged at the lower part of the car 200 and antennas may be arranged at the bottom of the hoistway. In this case, when the car 200 is located at the top floor, the wireless signal quality is most likely to be low, which is the opposite of the change in signal quality described in the embodiment. The fixed-side antenna is preferably located near the position where the elevator control device is installed.

[0073] Also, in the above-described embodiment, the setting changes of the transmission frequency and the transmission channel are performed by both the wireless device on the car side and the wireless device on the fixed side. However, the setting changes of the transmission frequency and the transmission channel may be performed by only one of them.

[0074] In the above-described embodiment, an example of applying it to an elevator is given assuming that the moving body and the fixed side perform wireless communication. On the other hand, as long as the moving body that moves along a predetermined path and the fixed side perform wireless communication, it may be applied to other moving bodies. For example, it may be applied to the case where a transport device that moves along a predetermined path in a warehouse and the fixed side perform wireless communication.

[0075] Also, in the configuration diagrams shown in FIGS. 2, 3, and 14, only the control lines and information lines considered necessary for explanation are shown, and not all the control lines and information lines are necessarily shown on the product. In reality, it may be considered that almost all the components are interconnected. In addition, when the system of this example is configured with an information processing device such as a computer, for the program that realizes the mobile body radio control system, in addition to preparing it in the non-volatile storage or memory in the computer, it may be placed in a recording medium such as an external memory, an IC card, an SD card, or an optical disk and transferred.

Explanation of Signs

[0076] 11… Radio signal measurement unit, 12… Door zone signal acquisition unit, 13… Moving distance calculation unit, 14… Radio quality database, 15… Moving direction estimation unit, 16… Relative position information database, 17… Absolute position estimation unit, 100… Control device, 101… Elevator control unit, 102… Radio 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… Radio devices (First radio device~Fourth radio device), 121~124… Antennas (fixed side), 201… Car side control unit, 202… Radio signal control unit, 211~214… Radio devices (First radio device~Fourth radio device), 221~224… Antennas (car side)

Claims

1. An N number (N is an integer of 2 or more) of antennas are installed on each of a moving body and a fixed side, N wireless transmission paths are formed by the N antennas of the moving body and the N antennas of the fixed side to perform wireless communication, and the transmission frequency or transmission channel in the N wireless transmission paths is switched to a plurality of transmission frequencies or transmission channels respectively to enable communication. A mobile wireless control system, A position acquisition unit that discretely acquires the moving position of the moving body, A transmission quality collection unit that collects the 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 in the N wireless transmission paths based on the discrete moving position of the moving body acquired by the position acquisition unit and the transmission quality at each transmission frequency or each transmission channel in each wireless transmission path collected by the transmission quality collection unit, A mobile wireless control system.

2. The combination setting unit sets an optimal transmission frequency or transmission channel in the N wireless transmission paths from the transmission quality collected by the transmission quality collection unit and the discrete moving position. The mobile wireless control system according to claim 1.

3. The combination setting unit estimates the transmission quality of the entire range where the moving body can move from the transmission quality collected by the transmission quality collection unit and the discrete moving position, and sets the 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 wireless control system according to claim 2.

4. The combination setting unit sets the transmission frequency or transmission channel at which the minimum value of the instantaneous value of the transmission quality collected by the transmission quality collection unit is the largest from a predetermined required signal quality value. The mobile wireless control system according to claim 2.

5. The moving body is an elevator car, The information on the discrete position acquired by the position acquisition unit is information indicating an absolute position using information indicating that it is within a door zone installed on the floor where the car stops and information about the floor where the car stops. The mobile wireless control system according to claim 2.

6. The moving body is an elevator car, The information on the discrete position acquired by the position acquisition unit is relative position information indicating that it is within a door zone provided on each floor where the car stops. The position acquisition unit determines the absolute position of the car based on the history of the detected relative position. The mobile body wireless control system according to claim 2.

7. In addition to the information on the relative position indicating that the car is within the door zone provided on each floor where the car stops, the position acquisition unit acquires the initial value of the floor where the car stops and determines the absolute position of the car. The mobile body wireless control system according to claim 6.

8. When an optimal solution for the optimal transmission frequency or transmission channel in the N-system wireless transmission path cannot be obtained, the combination setting unit issues an alarm indicating the corresponding situation. The mobile body wireless control system according to claim 1.

9. The mobile body is an elevator car. The N antennas of the mobile body are arranged at separated positions above or below the car. The N antennas on the fixed side are arranged at separated positions on the upper end side or the lower end side of the hoistway. The mobile body wireless control system according to any one of claims 1 to 8.

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 body wireless control method in which N-system wireless transmission paths are formed by the N antennas of the mobile body and the N antennas of the fixed side to perform wireless communication, and the transmission frequency or transmission channel in the N-system wireless transmission paths can be switched to a plurality of transmission frequencies or transmission channels for communication, including: A position acquisition process for acquiring the discrete movement positions of the mobile body; A transmission quality collection process for collecting the transmission quality during transmission at a plurality of prepared transmission frequencies or transmission channels in the N-system wireless transmission paths; A combination setting process for setting an optimal transmission frequency or transmission channel in the N-system wireless transmission paths based on the movement position of the mobile body acquired in the position acquisition process and the transmission quality at each transmission frequency or each transmission channel in each wireless transmission path collected in the transmission quality collection process. Mobile body wireless control method.

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