Communication device, receiving device, and monitoring system

Abstract

Provided is a communication device capable of reducing the amount of data exchanged when determining a communication state. The communication device has: a monitored-side transmission unit that transmits a monitored-side life-or-death signal to a receiving device; and a monitored-side timing determination unit that determines, on its own, the timing at which the monitored-side transmission unit transmits the monitored-side life-or-death signal to the receiving device. With this configuration, the communication device determines, on its own, the timing at which the monitored-side life-or-death signal is transmitted to the receiving device. At this time, the receiving device determines the communication state of the communication device based on whether the monitored-side life-or-death signal is received at this timing. Therefore, it is possible to reduce the amount of data exchanged when determining the communication state.

Description

Technical Field

[0001] The present invention relates to a communication device, a receiving device, and a monitoring system. Background Art

[0002] Patent Document 1 discloses a monitoring system. According to this monitoring system, the communication state of a communication device can be determined.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-067264 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] However, in the monitoring system described in Patent Document 1, the receiving device needs to send an acknowledgment signal to the communication device. Also, the communication device needs to send an acknowledgment response signal. Therefore, the amount of data exchanged when determining the communication state of the communication device increases.

[0008] The present invention has been completed in view of the above problems. An object of the present invention is to provide a communication device, a receiving device, and a monitoring system that can reduce the amount of data exchanged when determining the communication state.

[0009] Means for Solving the Problems

[0010] The communication device of the present invention includes: a monitored-side transmission unit that sends a monitored-side life-or-death signal to a receiving device; and a monitored-side timing determination unit that determines the timing at which the monitored-side transmission unit sends the monitored-side life-or-death signal to the receiving device.

[0011] The receiving device of the present invention includes: a monitoring-side timing determination unit that, when a plurality of communication devices each have the function of the communication device, determines the timing at which monitoring-side life-or-death signals are respectively generated at the same timing as the timing at which the plurality of communication devices respectively send the monitored-side life-or-death signals; a monitoring-side life-or-death signal generation unit that generates a plurality of monitoring-side life-or-death signals at the plurality of timings determined by the monitoring-side timing determination unit; and a life-or-death determination unit that, when the monitoring-side life-or-death signal generation unit generates a monitoring-side life-or-death signal and the monitored-side life-or-death signal is not received, determines that the communication device corresponding to the monitoring-side life-or-death signal is in a non-communication state.

[0012] The monitoring system of the present invention includes: a plurality of communication devices each having the function of the communication device; and the receiving device.

[0013] Effects of the Invention

[0014] According to these inventions, the communication device itself determines the timing for sending the life-or-death signal of the monitored side to the receiving device. At this time, the receiving device determines the communication state of the communication device based on whether the life-or-death signal of the monitored side is received at this timing. Since there is no need to assign information such as the ID of the determining device to the signal, the amount of data exchanged when determining the communication state can be reduced. Description of the Drawings

[0015] Figure 1 It is a structural diagram of the monitoring system according to Embodiment 1.

[0016] Figure 2 It is a diagram for explaining the method for the communication device of the monitoring system according to Embodiment 1 to determine the timing for sending the life-or-death signal of the monitored side.

[0017] Figure 3 It is a flowchart for explaining the outline of the operation of the communication device of the monitoring system according to Embodiment 1.

[0018] Figure 4 It is a flowchart for explaining the outline of the operation of the receiving device of the monitoring system according to Embodiment 1.

[0019] Figure 5 It is a hardware structural diagram of the communication device of the monitoring system according to Embodiment 1.

[0020] Figure 6 It is a structural diagram of the monitoring system according to Embodiment 1 in Embodiment 2.

[0021] Figure 7 It is a diagram for explaining the method for the receiving device of the monitoring system according to Embodiment 2 to estimate a communication device in a non-communication state.

[0022] Figure 8 It is a diagram for explaining the method for the receiving device of the monitoring system according to Embodiment 3 to estimate a communication device in a non-communication state. Detailed Embodiments

[0023] According to the accompanying drawings, the embodiments for implementing the present invention will be described. In addition, in each figure, the same or corresponding parts are labeled with the same reference numerals. The repeated description of this part is appropriately simplified or omitted.

[0024] Embodiment 1

[0025] Figure 1 It is a structural diagram of the monitoring system according to Embodiment 1.

[0026] For example, the monitoring system is set to be able to monitor a plurality of elevators 1.

[0027] The monitoring system includes a receiving device 3 and a plurality of communication devices 2.

[0028] Each communication device 2 of the plurality of communication devices 2 is provided corresponding to each elevator 1 of the plurality of elevators 1. Each of the plurality of communication devices 2 includes a monitored-side transmission unit 2a, a monitored-side reception unit 2b, a monitored-side time determination unit 2c, a monitored-side random number generation unit 2d, a monitored-side comparison unit 2e, a monitored-side life / death signal generation unit 2f, and an acknowledgement response signal generation unit 2g.

[0029] For example, the receiving device 3 is incorporated into a cloud server. For example, the receiving device 3 is incorporated near the communication device 2. The receiving device 3 includes a monitoring-side reception unit 3a, a monitoring-side transmission unit 3b, a monitoring-side time determination unit 3c, a plurality of monitoring-side random number generation units 3d, a monitoring-side comparison unit 3e, a monitoring-side life / death signal generation unit 3f, a signal comparison unit 3g, a life / death determination unit 3h, a corresponding device confirmation unit 3i, and an acknowledgement signal generation unit 3j.

[0030] In each of the plurality of communication devices 2, the monitored-side time determination unit 2c, the monitored-side random number generation unit 2d, and the monitored-side comparison unit 2e serve as a monitored-side timing determination unit, and determine by itself the timing at which the monitored-side transmission unit 2a transmits the monitored-side life / death signal to the receiving device 3. The monitored-side life / death signal generation unit 2f generates a monitored-side life / death signal such that the monitored-side transmission unit 2a transmits the monitored-side life / death signal to the receiving device 3 at the determined timing. The monitored-side transmission unit 2a transmits the monitored-side life / death signal to the receiving device 3.

[0031] In the receiving device 3, the monitoring-side reception unit 3a receives the monitored-side life / death signals from the plurality of communication devices 2. The monitoring-side time determination unit 3c, the plurality of monitoring-side random number generation units 3d, and the monitoring-side comparison unit 3e serve as a monitoring-side timing determination unit, and determine the timing at which the monitoring-side life / death signals are respectively generated at the same timing as the timing at which the plurality of communication devices 2 respectively transmit the monitored-side life / death signals. The monitoring-side life / death signal generation unit 3f generates a plurality of monitoring-side life / death signals respectively at the determined plurality of timings.

[0032] The signal comparison unit 3g compares the number of the generated monitoring-side life / death signals with the number of the received monitored-side life / death signals.

[0033] The alive / dead determination unit 3h determines the communication device 2 in a non - communicable state based on the comparison result of the signal comparison unit 3g. For example, when the monitoring - side alive / dead signal generation unit 3f generates a monitoring - side alive / dead signal and the monitored - side alive / dead signal is not received, the alive / dead determination unit 3h determines that the communication device 2 corresponding to the monitoring - side alive / dead signal is in a non - communicable state. For example, when the monitoring - side alive / dead signal generation unit 3f generates multiple monitoring - side alive / dead signals simultaneously and the number of received monitored - side alive / dead signals is less than the number of generated monitoring - side alive / dead signals, the alive / dead determination unit 3h determines that any one of the multiple communication devices 2 corresponding to the multiple monitoring - side alive / dead signals is in a non - communicable state.

[0034] At this time, the corresponding device confirmation unit 3i identifies the multiple communication devices 2 corresponding to the multiple monitoring - side alive / dead signals respectively. The confirmation signal generation unit 3j generates a confirmation signal to be sent to the multiple communication devices 2. The monitoring - side transmission unit 3b sends the confirmation signal generated by the confirmation signal generation unit 3j to the multiple communication devices 2.

[0035] In each of the multiple communication devices 2, the monitored - side receiving unit 2b receives the confirmation signal from the receiving device 3. The confirmation response signal generation unit 2g generates a confirmation response signal when the monitored - side receiving unit 2b receives the confirmation signal. In the communication device 2 in a communicable state among the multiple communication devices 2, the monitored - side transmission unit 2a sends the confirmation response signal to the receiving device 3. In the communication device 2 not in a non - communicable state, the monitored - side transmission unit 2a does not send the confirmation response signal to the receiving device 3.

[0036] In the receiving device 3, the monitoring - side receiving unit 3a receives the confirmation response signals from the multiple communication devices 2. The receiving device 3 identifies the non - communicable communication device 2 based on the reception status of the confirmation response signals.

[0037] Next, use Figure 2 to describe the method for determining the timing of sending the monitored - side alive / dead signal.

[0038] Figure 2 is a diagram for explaining the method for determining the timing of a communication device in the monitoring system of Embodiment 1 to send a monitored - side alive / dead signal. Figure 2 The horizontal axis of Figure 2 is time.

[0039] In Figure 2 the single - dotted line represents the output value of only the minutes of the current time by the monitored - side time determination unit 2c. Each point represents the output value of the monitored - side random number generation unit 2d.

[0040] The monitored-side random number generator 2d outputs signals at constant intervals. When the output value at this time is the same as the output value at the current time, the monitored-side comparator 2e notifies the transmission of the monitored-side life-or-death signal.

[0041] The output values of the monitored-side random number generator 2d are set to have no correlation among multiple communication devices 2. In this case, the two communication devices 2 do not always send the monitored-side life-or-death signals at the same timing. As a result, the receiving device 3 can grasp the communication device 2 in a non-communication state.

[0042] As the simplest method, a uniform random number generator with independent seeds input in each of the multiple communication devices 2 can be used as the monitored-side random number generator 2d. For example, a pseudo-random number generator installed with software such as the linear congruential method or Xorshift can also be used as the monitored-side random number generator 2d. For example, a hardware random number generator using thermal noise or the like can also be used as the monitored-side random number generator 2d. For example, a cryptographic pseudo-random number generator based on a hash function such as SHA can also be used as the monitored-side random number generator 2d.

[0043] In addition, a timing generator based on the operating state of the elevator 1 can also be used as the monitored-side random number generator 2d. For example, a timing generator based on the current floor of the car of the elevator 1 can also be used as the monitored-side random number generator 2d. For example, a timing generator based on the current acceleration of the car of the elevator 1 can also be used as the monitored-side random number generator 2d. For example, a timing generator based on the cumulative number of starts of the car of the elevator 1 can also be used as the monitored-side random number generator 2d. For example, a timing generator based on the current value of the current flowing through the traction machine of the elevator 1 can also be used as the monitored-side random number generator 2d.

[0044] At this time, in adjacent elevators 1, similar output values may occur. In this case, a pseudo-random number generator with the data of the operating state of the elevator 1 as the seed can also be used as the monitored-side random number generator 2d.

[0045] In addition, a timing generator based on the attributes of the elevator 1 can also be used as the monitored-side random number generator 2d. For example, a timing generator based on the specifications of the elevator 1 such as the floor and speed of the elevator 1 can also be used as the monitored-side random number generator 2d. For example, a timing generator based on the usage mode of the elevator 1 such as a station or an office can also be used as the monitored-side random number generator 2d.

[0046] The attributes of the elevator 1 result in differences in the frequency requirements for life-or-death monitoring. For example, in a station, life-or-death monitoring with a higher frequency is required than in a residential apartment.

[0047] In the monitored-side random number generation unit 2d that generates random numbers according to a specific distribution corresponding to the attributes of the elevator 1, a Gaussian distribution S(x) with an average value μ and a variance σ is output. Specifically, S(x) is represented by the following equation (1). 2 Specifically, S(x) is represented by the following equation (1).

[0048]

[0049] For example, in a specific group of objects such as a residential apartment, a parameter with an average value of 20 of the Gaussian distribution is assigned. For example, in other groups of objects such as a station, a parameter with an average value of 40 of the Gaussian distribution is assigned. As a result, it is possible to shift the generation time of the monitored-side alive / dead signals of multiple groups of objects to an arbitrary time range. In addition, the monitored-side alive / dead signals can be transmitted frequently by changing the generation time interval of the monitored-side alive / dead signals.

[0050] Next, the operation outline of the communication device 2 is described using Figure 3 The operation outline of the communication device 2 is described using

[0051] Figure 3 is a flowchart for explaining the operation outline of the communication device of the monitoring system according to Embodiment 1.

[0052] In step S1, the communication device 2 refers to the current time. Then, the communication device 2 performs the operation of step S2. In step S2, the communication device 2 determines whether the current time is a random number generation time.

[0053] If the current time is not a random number generation time in step S2, the communication device 2 performs the operation of step S1. If the current time is a random number generation time in step S2, the communication device 2 performs the operation of step S3.

[0054] In step S3, the communication device 2 generates a random number. Then, the communication device 2 performs the operation of step S4. In step S4, the communication device 2 determines whether the random number is the same as the current time.

[0055] If the random number is different from the current time in step S4, the communication device 2 ends the operation.

[0056] If the random number is the same as the current time in step S4, the communication device 2 performs the operation of step S5. In step S5, the communication device 2 transmits the monitored-side alive / dead signal. Then, the communication device 2 ends the operation.

[0057] Next, the operation outline of the receiving device 3 is described using Figure 4 The operation outline of the receiving device 3 is described using

[0058] Figure 4 is a flowchart for explaining the operation outline of the receiving device of the monitoring system according to Embodiment 1.

[0059] In step S11, the receiving device 3 refers to the current time. Then, the receiving device 3 performs the operation of step S12. In step S12, the receiving device 3 determines whether the current time is a random number generation time.

[0060] When the current time in step S12 is not a random number generation time, the receiving device 3 performs the operation of step S11. When the current time in step S12 is a random number generation time, the receiving device 3 performs the operation of step S13.

[0061] In step S13, the receiving device 3 generates random numbers corresponding to all communication devices 2. Then, the receiving device 3 performs the operation of step S14. In step S14, the receiving device 3 determines whether there is a random number identical to the current time.

[0062] When there is no random number identical to the current time in step S14, the receiving device 3 ends the operation.

[0063] When there is a random number identical to the current time in step S14, the receiving device 3 performs the operation of step S15. In step S15, the receiving device 3 compares the number of generated monitoring-side life / death signals with the number of received monitored-side life / death signals. Then, the receiving device 3 performs the operation of step S16. In step S16, the receiving device 3 determines whether the number of generated monitoring-side life / death signals is the same as the number of received monitored-side life / death signals.

[0064] When the number of generated monitoring-side life / death signals is the same as the number of received monitored-side life / death signals in step S16, the receiving device 3 ends the operation.

[0065] When the number of generated monitoring-side life / death signals is not the same as the number of received monitored-side life / death signals in step S16, the receiving device 3 performs the operation of step S17. In step S17, the receiving device 3 performs an operation for life / death confirmation. Then, the receiving device 3 ends the operation.

[0066] According to the first embodiment described above, the communication device 2 itself determines the timing for sending the monitored-side life / death signal to the receiving device 3. At this time, the receiving device 3 determines the communication state of the communication device 2 based on whether the monitored-side life / death signal is received at this timing. Therefore, the amount of data exchanged when determining the communication state of the communication device 2 can be reduced. As a result, the load on the network can be alleviated.

[0067] In addition, the monitored-side life / death signal is generated at this timing. Therefore, the situation of uselessly generating the monitored-side life / death signal can be suppressed. As a result, the mistransmission of the monitored-side life / death signal can be suppressed.

[0068] In addition, this timing is determined based on uniformly distributed random numbers. Therefore, this timing can be determined with a simple structure.

[0069] In addition, this timing is determined based on the operating state of the corresponding elevator 1. Therefore, the monitored side alive / dead signal can be transmitted at a timing suitable for the corresponding elevator 1.

[0070] In addition, this timing is determined based on the attributes of the corresponding elevator 1. Therefore, the monitored side alive / dead signal can be transmitted at a timing suitable for the corresponding elevator 1.

[0071] In addition, when the output random number of the random number generation unit follows a uniform distribution and the timing is controlled in minutes, the collision probability P caused by n communication devices 2 out of N communication devices 2 generating the monitored side alive / dead signal at the same time c is represented by the following formula (2) using the binomial distribution.

[0072]

[0073] When simply using the identification information, at most 256 communication devices 2 can be monitored with 1 byte. However, according to this method, when the output random number of the random number generation unit follows a uniform distribution, a collision probability P of 0.37 is allowed c , thereby enabling an increase in the number of communication devices 2 that can be monitored.

[0074] In addition, the probability P that a certain communication device 2 does not transmit the monitored side alive / dead signal within m minutes nt is represented by the following formula (3).

[0075]

[0076] In this case, the monitored side alive / dead signal is transmitted with a probability of approximately 0.64 within 60 minutes. In order to shorten the interval for transmitting the monitored side alive / dead signal, it is only necessary to shorten the interval for generating random numbers.

[0077] Next, an example of the communication device 2 will be described using Figure 5 FIG.

[0078] Figure 5 is a hardware structure diagram of the communication device of the monitoring system according to Embodiment 1.

[0079] Each function of the communication device 2 can be implemented by a processing circuit. For example, the processing circuit has at least one processor 4a and at least one memory 4b. For example, the processing circuit has at least one dedicated hardware 5.

[0080] In the case where the processing circuit has at least one processor 4a and at least one memory 4b, each function of the communication device 2 is implemented by software, firmware, or a combination of software and firmware. At least one of the software and the firmware is denoted as a program. At least one of the software and the firmware is stored in at least one memory 4b. The at least one processor 4a realizes each function of the communication device 2 by reading and executing the program stored in the at least one memory 4b. The at least one processor 4a is also referred to as a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, or a DSP. For example, the at least one memory 4b is a non-volatile or volatile semiconductor memory such as a RAM, a ROM, a flash memory, an EPROM, or an EEPROM, a magnetic disk, a floppy disk, an optical disk, a compact disk, a mini disk, or a DVD.

[0081] In the case where the processing circuit has at least one dedicated hardware 5, the processing circuit is implemented, for example, by a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof. For example, each function of the communication device 2 is implemented by the processing circuit respectively. For example, each function of the communication device 2 is implemented by the processing circuit uniformly.

[0082] Regarding each function of the communication device 2, a part can also be implemented by the dedicated hardware 5, and the other part can be implemented by software or firmware. For example, it can also be that the function of the monitored-side random number generation unit 2d is implemented by the processing circuit as the dedicated hardware 5, and the functions other than the function of the monitored-side random number generation unit 2d are implemented by the at least one processor 4a reading and executing the program stored in the at least one memory 4b.

[0083] In this way, the processing circuit implements each function of the communication device 2 through the hardware 5, software, firmware, or a combination thereof.

[0084] Although not shown, each function of the receiving device 3 can also be implemented by a processing circuit equivalent to the processing circuit that implements each function of the communication device 2.

[0085] Embodiment 2

[0086] Figure 6 It is a structural diagram of the monitoring system of Embodiment 1 in Embodiment 2. In addition, the same reference numerals are given to the parts that are the same as or corresponding to the parts of Embodiment 1. The description of this part is omitted.

[0087] In Embodiment 2, the receiving device 3 does not have a monitored-side transmission unit 3b, a corresponding device confirmation unit 3i, and a confirmation signal generation unit 3j. The receiving device 3 has an estimation unit 3k.

[0088] When multiple monitored-side life-or-death signals are simultaneously generated by the monitored-side life-or-death signal generation unit 3f, and the number of received monitored-side life-or-death signals is less than the number of generated monitored-side life-or-death signals, the estimation unit 3k estimates the communication device 2 in a non-communication state based on the comparison result between the number of subsequently generated monitored-side life-or-death signals and the number of received monitored-side life-or-death signals. For example, the estimation unit 3k estimates the communication device 2 in a non-communication state based on the curve graph theory.

[0089] Next, use Figure 7 to illustrate the estimation method of the communication device 2 in a non-communication state.

[0090] Figure 7 It is a diagram for explaining the estimation method of the receiving device of the monitoring system according to Embodiment 2 for a communication device in a non-communication state.

[0091] In Figure 7 the lower circle is a node representing the communication device 2. The solid line represents the communication device 2 in a communication state. The dashed line represents the communication device 2 in a non-communication state. The quadrilateral is a function node for calculating the total number of received monitored-side life-or-death signals at the corresponding moment. The triangle is a node representing the reception status of the monitored-side life-or-death signal. White represents the situation where all the monitored-side life-or-death signals that should be received have been received. Black represents the situation where not all the monitored-side life-or-death signals that should be received should be received.

[0092] For example, when the time t is "1", the communication device 2 of "1" and the communication device 2 of "3" send monitored-side life-or-death signals, and these monitored-side life-or-death signals are correctly received. At this time, the number of received packets is consistent with the number of connections in the graph, and it is determined that the communication device 2 of "1" and the communication device 2 of "3" are in a communication state.

[0093] For example, when the time t is "2", the communication device 2 of "2", the communication device 2 of "3", and the communication device 2 of "6" should send monitored-side life-or-death signals, but the communication device 2 of "2" does not send the monitored-side life-or-death signal. In this case, an abnormality is detected. At this time point, it is impossible to estimate the communication device 2 in a non-communication state among the communication device 2 of "2", the communication device 2 of "3", and the communication device 2 of "6".

[0094] For example, when the time t is "3", the communication device 2 of "8" should send a monitored-side life-or-death signal, but the communication device 2 of "8" does not send the monitored-side life-or-death signal. In this case, an abnormality is detected. At this time point, it is determined that the communication device 2 of "8" is in a non-communication state.

[0095] When the time t advances to "5", based on the communication device 2 that should send the life-or-death signal of the monitored side before this time point and the number of received packets, it is estimated that the communication device 2 in a non-communication state at time t of "2" is the communication device 2 of "2".

[0096] According to the second embodiment described above, when the number of received life-or-death signals of the monitored side is less than the number of generated life-or-death signals of the monitoring side, the receiving device 3 estimates the communication device 2 in a non-communication state based on the comparison result between the number of subsequently generated life-or-death signals of the monitoring side and the number of received life-or-death signals of the monitored side. Specifically, the receiving device 3 estimates the communication device 2 in a non-communication state based on the curve theory. Therefore, it is possible to determine the communication device 2 in a non-communication state without sending an acknowledgment signal.

[0097] Embodiment 3

[0098] Figure 8 It is a diagram for explaining the estimation method of the communication device in a non-communication state by the receiving device of the monitoring system according to Embodiment 3. In addition, the same reference numerals are assigned to the parts that are the same as or corresponding to those of the second embodiment. The description of this part is omitted.

[0099] In the receiving device 3 of Embodiment 3, the estimation unit 3k estimates the communication device 2 in a non-communication state based on compressive sensing, which is a method of estimating a high-dimensional vector (sparse vector) with many zero elements using the number of observations less than the dimension of the vector.

[0100] The sparse vector x to be estimated is represented by the following equation (4).

[0101]

[0102] The observation vector y is represented by the following equation (5).

[0103]

[0104] Among them, M is less than n.

[0105] At this time, the M×N matrix A for estimating the sparse vector x is represented by the following equation (6).

[0106]

[0107] The relationship among the sparse vector x, the observation vector y, and the M×N matrix A is represented by the following equation (7).

[0108] y = Ax (7)

[0109] At this time, the estimation unit 3k solves the following equation (8) to estimate the vector x.

[0110]

[0111] Here, the following equation (8) represents the norm.

[0112] ||·|| p (9)

[0113] When p is greater than 0, the following equation (10) holds.

[0114]

[0115] When p is 0, the norm is represented by the following equation (11).

[0116] ||b||0 (11)

[0117] In equation (11), the norm represents the number of non-zero elements of vector b.

[0118] In the receiving device 3, the received signal y represents the number of life-or-death signals of the monitored side received at a certain time. x represents the operating status of the communication device 2. For example, when the communication device 2 is in a communicable state, x is non-zero. When the communication device 2 is in a non-communicable state, x is zero.

[0119] In Figure 8 , the life-or-death status of 8 communication devices 2 is estimated based on 5 observation conditions. At this time, the signal input / output is represented by the following equation (12).

[0120]

[0121] However, in equation (12), most of the elements of the vector to be estimated are non-zero elements. Therefore, it is not a problem that can be solved by compressive sensing. In an actual system, it is not easy for the situation where most of the communication devices 2 are in a non-communicable state to occur, and almost all of the communication devices 2 are in a communicable state. Therefore, for the convenience of sparse estimation of the vector, zero is set as the communicable state and non-zero is set as the non-communicable state. However, the observer does not know the true vector. In this state, the number of observed signals is inconsistent with the head and tail. Therefore, let the number of signals to be received at time point t be r t , and the elements of the new observed vector are defined by the following equation (13).

[0122]

[0123] As a result, the signal input / output is transformed into the following equation (14).

[0124]

[0125] The estimation unit 3k grasps the number of signals that should actually be received. Therefore, the estimation unit 3k calculates the left side based on the number of signals actually received. In addition, since the transformation matrix shares a random number generator, it is also known. Therefore, the estimation unit 3k sparsifies the operation status vector on the right side and processes it as an estimation problem of compressive sensing.

[0126] According to the third embodiment described above, the receiving device 3 estimates the communication device 2 in a non - communicable state based on compressive sensing. In this case, it is also possible to determine the communication device 2 in a non - communicable state without transmitting a confirmation signal.

[0127] Alternatively, the communication device 2 in a non - communicable state can be estimated based on the pseudo - inverse matrix. In this case, it is also possible to determine the communication device 2 in a non - communicable state without transmitting a confirmation signal.

[0128] Industrial Applicability

[0129] As described above, the communication device, receiving device, and monitoring system of the present invention can be used in an elevator system.

[0130] Reference Numeral Explanation

[0131] 1: Elevator; 2: Communication device; 2a: Monitored - side transmitting unit; 2b: Monitored - side receiving unit; 2c: Monitored - side time determination unit; 2d: Monitored - side random number generation unit; 2e: Monitored - side comparison unit; 2f: Monitored - side alive - dead signal generation unit; 2g: Confirmation response signal generation unit; 3: Receiving device; 3a: Monitoring - side receiving unit; 3b: Monitoring - side transmitting unit; 3c: Monitoring - side time determination unit; 3d: Monitoring - side random number generation unit; 3e: Monitoring - side comparison unit; 3f: Monitoring - side alive - dead signal generation unit; 3g: Signal comparison unit; 3h: Alive - dead determination unit; 3i: Corresponding device confirmation unit; 3j: Confirmation signal generation unit; 3k: Estimation unit; 4a: Processor; 4b: Memory; 5: Hardware.

Claims

1. A communication device, which has: A monitored - side transmitting unit that transmits a monitored - side life - and - death signal to a receiving device; and A monitored - side timing determination unit that determines, according to a random number generated by itself, the timing at which the monitored - side transmitting unit transmits the monitored - side life - and - death signal to the receiving device, The receiving device determines, at the same timing as the timings at which the plurality of communication devices respectively transmit the monitored - side life - and - death signals, the timings for respectively generating monitored - side life - and - death signals, and respectively generates a plurality of monitored - side life - and - death signals at the determined timings for generating the monitored - side life - and - death signals; when a plurality of monitored - side life - and - death signals are generated, if the number of received monitored - side life - and - death signals is less than the number of generated monitored - side life - and - death signals, it is determined that any one of the plurality of communication devices corresponding to the plurality of monitored - side life - and - death signals is in a non - communicable state.

2. The communication device according to claim 1, wherein, The communication device has a monitored - side life - and - death signal generation unit that generates a monitored - side life - and - death signal such that the monitored - side transmitting unit transmits the monitored - side life - and - death signal to the receiving device at the timing determined by the monitored - side timing determination unit according to the generated random number.

3. The communication device according to claim 1 or 2, wherein, The monitored - side timing determination unit determines, according to a uniform random number, the timing at which the monitored - side transmitting unit transmits the monitored - side life - and - death signal to the receiving device.

4. A communication device, which has: A monitored - side transmitting unit that transmits a monitored - side life - and - death signal to a receiving device; and A monitored - side timing determination unit that determines by itself the timing at which the monitored - side transmitting unit transmits the monitored - side life - and - death signal to the receiving device, The monitored - side timing determination unit determines, according to the operating state of the corresponding elevator, the timing at which the monitored - side transmitting unit transmits the monitored - side life - and - death signal to the receiving device, The receiving device determines, at the same timing as the timings at which the plurality of communication devices respectively transmit the monitored - side life - and - death signals, the timings for respectively generating monitored - side life - and - death signals, and respectively generates a plurality of monitored - side life - and - death signals at the determined timings for generating the monitored - side life - and - death signals; when a plurality of monitored - side life - and - death signals are generated, if the number of received monitored - side life - and - death signals is less than the number of generated monitored - side life - and - death signals, it is determined that any one of the plurality of communication devices corresponding to the plurality of monitored - side life - and - death signals is in a non - communicable state.

5. A communication device, which has: A monitored - side transmitting unit that transmits a monitored - side life - and - death signal to a receiving device; and A monitored - side timing determination unit that determines by itself the timing at which the monitored - side transmitting unit transmits the monitored - side life - and - death signal to the receiving device, The monitored - side timing determination unit determines, according to the attributes of the corresponding elevator, the timing at which the monitored - side transmitting unit transmits the monitored - side life - and - death signal to the receiving device, The receiving device determines the timings for separately generating the monitoring - side life - or - death signals at the same timings as those when the plurality of communication devices respectively send the monitored - side life - or - death signals, and separately generates a plurality of monitoring - side life - or - death signals at the determined timings for generating the monitoring - side life - or - death signals; when a plurality of monitoring - side life - or - death signals are generated, if the number of received monitored - side life - or - death signals is less than the number of generated monitoring - side life - or - death signals, it is determined that any one of the plurality of communication devices corresponding to the plurality of monitoring - side life - or - death signals is in a non - communicable state.

6. A receiving device, comprising: A monitoring - side timing determination unit that, when the plurality of communication devices respectively have the functions of the communication device according to any one of claims 1 to 5, determines the timings for separately generating the monitoring - side life - or - death signals at the same timings as those when the plurality of communication devices respectively send the monitored - side life - or - death signals; A monitoring - side life - or - death signal generation unit that separately generates a plurality of monitoring - side life - or - death signals at the plurality of timings determined by the monitoring - side timing determination unit; And A life - or - death determination unit that, when the monitoring - side life - or - death signal generation unit generates a plurality of monitoring - side life - or - death signals, if the number of received monitored - side life - or - death signals is less than the number of generated monitoring - side life - or - death signals, determines that any one of the plurality of communication devices corresponding to the plurality of monitoring - side life - or - death signals is in a non - communicable state.

7. The receiving device according to claim 6, wherein The receiving device has a monitoring - side confirmation signal generation unit that, when the monitoring - side life - or - death signal generation unit simultaneously generates a plurality of monitoring - side life - or - death signals and the number of received monitored - side life - or - death signals is less than the number of generated monitoring - side life - or - death signals, generates a monitoring - side confirmation signal to be sent to the plurality of communication devices corresponding to the plurality of monitoring - side life - or - death signals.

8. A monitoring system, comprising: A plurality of communication devices that respectively have the functions of the communication device according to any one of claims 1 to 5; and The receiving device according to claim 6 or 7.

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