Control device, control method, and control program

Abstract

This control device (100) comprises a storage unit (110), an acquisition unit (130), and a control unit (140). When a first disturbance signal is acquired by the acquisition unit (130), the control unit (140) uses the first disturbance signal to perform control for cancelling noise picked up by an error microphone (300) from a signal picked up by the error microphone (300) while an elevator car (10) is moving. When a second disturbance signal is acquired by the acquisition unit (130), the control unit (140) uses the second disturbance signal to perform control for cancelling noise picked up by a reference microphone (200) from a signal picked up by the reference microphone (200) while the elevator car (10) is moving.

Description

Control device, control method, and control program

[0001] The present disclosure relates to a control device, a control method, and a control program.

[0002] Noise inside an elevator car is unpleasant for people inside the car. Therefore, technologies for eliminating noise have been proposed. For example, an active noise reduction device is installed in an elevator car, as described in Patent Document 1. The active noise reduction device reduces noise at the noise inlet of the car.

[0003] Japanese Patent Application Publication No. 6-239571

[0004] Incidentally, when an elevator car is moving, noises such as inherent vibrations and motor sounds are input to the microphone, reducing coherence.

[0005] The purpose of this disclosure is to prevent the loss of coherence.

[0006] According to one aspect of the present disclosure, there is provided a control device. The control device is connected to a reference microphone, an error microphone, and a speaker. The control device performs active noise control. The control device includes a memory unit, an acquisition unit that acquires from the memory unit either or both of a first disturbance signal, which is a signal of noise generated by the movement of an elevator car and picked up by the error microphone, obtained from a sound signal picked up by the error microphone while the elevator car is moving, and a second disturbance signal, which is a signal of noise generated by the movement of the elevator car and picked up by the reference microphone, obtained from a sound signal picked up by the reference microphone while the elevator car is moving, and a control unit. When the first disturbance signal is acquired, the control unit uses the first disturbance signal to perform control to cancel the noise picked up by the error microphone from the signal picked up by the error microphone while the elevator car is moving. When the second disturbance signal is acquired, the control unit uses the second disturbance signal to perform control to cancel out the noise picked up by the reference microphone from the signal picked up by the reference microphone while the elevator car is moving.

[0007] According to the present disclosure, it is possible to prevent a decrease in coherence.

[0008] 1 is a diagram illustrating an example of a control system according to a first embodiment; FIG. 2 is a diagram illustrating hardware included in a control device according to the first embodiment; FIG. 3 is a block diagram illustrating functions of a control device according to the first embodiment; FIG. 4 is a diagram illustrating feedforward control according to the first embodiment; (A) and (B) are graphs illustrating coherence according to the first embodiment; (C) is a graph illustrating a noise reduction amount according to the first embodiment; and FIG. 5 is a diagram illustrating an example of a control system according to a second embodiment.

[0009] Hereinafter, an embodiment will be described with reference to the drawings.

[0010] Embodiment 1. FIG. 1 is a diagram showing an example of a control system according to embodiment 1. FIG. 1 shows an elevator car 10 and a duct 11. The elevator car 10 moves up and down. The control system includes a control device 100, a reference microphone 200, an error microphone 300, and a speaker 400. Note that "microphone" is an abbreviation for microphone. The control device 100, the reference microphone 200, the error microphone 300, and the speaker 400 are connected via a network. The control device 100 is a device that executes a control method. The reference microphone 200 may be called a sensing microphone. The reference microphone 200 may be called a second microphone. The error microphone 300 may be called a first microphone.

[0011] Next, the hardware of the control device 100 will be described. Fig. 2 is a diagram showing the hardware of the control device of embodiment 1. The control device 100 is also called a computer. The control device 100 has a processor 101, a volatile storage device 102, and a non-volatile storage device 103.

[0012] The processor 101 controls the entire control device 100. For example, the processor 101 is a central processing unit (CPU), a field programmable gate array (FPGA), a digital signal processor (DSP), a micro-control unit (MCU), or the like. The processor 101 may be a multiprocessor. The control device 100 may also have a processing circuit.

[0013] The volatile memory device 102 is a main memory device of the control device 100. For example, the volatile memory device 102 is a random access memory (RAM). The nonvolatile memory device 103 is an auxiliary memory device of the control device 100. For example, the nonvolatile memory device 103 is a hard disk drive (HDD) or a solid state drive (SSD).

[0014] Next, a description will be given of functions of the control device 100. Fig. 3 is a block diagram showing functions of the control device according to embodiment 1. The control device 100 includes a storage unit 110, an identification unit 120, an acquisition unit 130, and a control unit 140.

[0015] The storage unit 110 may be realized as a storage area secured in the volatile storage device 102 or the non-volatile storage device 103. The storage unit 110 may also be called a memory. Some or all of the identification unit 120, the acquisition unit 130, and the control unit 140 may be realized by a processing circuit. Furthermore, some or all of the identification unit 120, the acquisition unit 130, and the control unit 140 may be realized as program modules executed by the processor 101. For example, the program executed by the processor 101 is also called a control program or a control program product. For example, the control program is recorded on a recording medium.

[0016] The storage unit 110 stores various information. The functions of the identification unit 120, acquisition unit 130, and control unit 140 will be described later.

[0017] The control device 100 reduces noise by ANC (Active Noise Control). Specifically, the control device 100 reduces noise by using feedforward control. Although feedforward control is a conventional technique, the feedforward control will be simply described below.

[0018] FIG. 4 is a diagram for explaining the feedforward control of the first embodiment. FIG. 4 shows an ANC system. x(n) represents the sound signal input to the reference microphone 200. d(n) represents the sound signal input to the error microphone 300. e(n) is the same as d(n). However, for convenience, e(n) is expressed differently from d(n) in accordance with the adaptive algorithm. P(z) represents the primary path. S1(z) represents the secondary path. S2(z) represents the secondary path model. y(n) is the secondary sound source drive signal.

[0019] The control device 100 uses feedforward control to output a sound that is in the opposite phase to the noise sound from the speaker 400. This reduces the noise. The noise sound may be any sound. For example, the noise sound may be the sound of a fan.

[0020] When the elevator car 10 is moving, noise such as inherent vibrations and motor sounds is input to the error microphone 300, reducing coherence. Therefore, the control device 100 stores a signal indicative of the noise in advance. Then, when the elevator car 10 is moving, the control device 100 performs feedforward control to cancel out the noise. This allows the control device 100 to prevent a reduction in coherence.

[0021] Here, the noise may be expressed as a sound generated by the movement of the elevator car 10. The noise may also be expressed as a disturbance noise. The sound signal of the noise is called a disturbance signal. Figure 4 shows the disturbance signal w(n).

[0022] The above is a brief description of the processing of the control device 100. The following describes the processing of the control device 100 in detail.

[0023] First, the process up to when the disturbance signal w(n) is stored in the control device 100 will be described. The identification unit 120 calculates P(z) based on a sound signal in a high coherence state. Note that, for example, a high coherence state occurs when the elevator car 10 is stopped. The sound of the sound signal is a sound recorded when the speaker 400 is not outputting sound. Specifically, the identification unit 120 calculates P(z) using equation (1). Note that D(z) represents the z-transform of d(n). Furthermore, Q represents the integration path.

[0024]

[0025] H(z) is expressed by equation (2), where T denotes transposition.

[0026]

[0027] p is expressed by equation (3). Note that N is a positive integer. R represents a real number. R may be considered as a set of real numbers.

[0028]

[0029] z is expressed by equation (4). Note that C represents a complex number. C may be considered as a set of complex numbers.

[0030]

[0031] The determination unit 120 calculates W(z) based on a sound signal of a sound recorded while the elevator car 10 is moving and noise based on the disturbance signal w(n) is input to the error microphone 300. Note that the sound of the sound signal is a sound recorded while the speaker 400 is not outputting sound. Note that W(z) represents the z-transform of w(n). Specifically, the determination unit 120 calculates W(z) by transforming equation (5). That is, W(z) is expressed by equation (6). Note that P(z) in equations (5) and (6) is P(z) calculated by equation (1). X(z) represents the z-transform of x(n).

[0032]

[0033] This allows the identifying unit 120 to identify the disturbance signal w(n).

[0034] The identification unit 120 stores the disturbance signal w(n) in the memory unit 110. Alternatively, the identification unit 120 may store information indicating the disturbance signal w(n) in the memory unit 110. When the disturbance signal w(n) is stored in the memory unit 110, the identification unit 120 performs an inverse z-transform on W(z) and stores the disturbance signal w(n) obtained by the inverse z-transform in the memory unit 110. The identification unit 120 may also store W(z) in the memory unit 110. Here, the disturbance signal w(n) is also referred to as a first disturbance signal. That is, the disturbance signal w(n) is noise generated by the movement of the elevator car 10 and is a sound signal of the noise input to the error microphone 300. W(z) is also referred to as a first z-transformed disturbance signal obtained by z-transforming the disturbance signal w(n). In this manner, the disturbance signal w(n) is stored in the control device 100.

[0035] Furthermore, the disturbance signal w(n) varies depending on the weight of the number of passengers in the elevator car 10. Therefore, the identification unit 120 may calculate the disturbance signal w(n) taking into account the load weight of the elevator car 10, etc.

[0036] The identification unit 120 may perform the above calculation using sounds obtained from multiple elevators. As a result, a disturbance signal corresponding to each elevator is obtained. The identification unit 120 may select one disturbance signal from the multiple disturbance signals using maximum likelihood estimation, Bayesian estimation, or the like, and store the selected disturbance signal in the storage unit 110 as the disturbance signal w(n).

[0037] The disturbance signal w(n) changes due to aging of the elevator, so the identification unit 120 may calculate the disturbance signal w(n) periodically.

[0038] Next, a case will be described in which the disturbance signal w(n) stored in the storage unit 110 is used. The acquisition unit 130 acquires the disturbance signal w(n) or W(z) from the storage unit 110. This acquisition process is also referred to as a first acquisition process.

[0039] When elevator car 10 is moving and noise based on disturbance signal w(n) is input to error microphone 300, control unit 140 performs control to cancel the noise using the acquired disturbance signal w(n) or W(z). This sentence can also be expressed as follows: When elevator car 10 is moving and noise is input to error microphone 300, control unit 140 performs control to cancel the noise using the acquired disturbance signal w(n) or W(z), and also performs feedforward control of noise sound in duct 11 of elevator car 10 using reference microphone 200, error microphone 300, and speaker 400. The control will be described in detail below.

[0040] When the disturbance signal w(n) is acquired, the control unit 140 performs z-transform on the disturbance signal w(n), thereby obtaining W(z).

[0041] When the elevator car 10 is moving and the speaker 400 is driven, D(z) is expressed by equation (7), where Y(z) represents the z-transform of y(n).

[0042]

[0043] As shown in equation (7), D(z) contains W(z). Therefore, the control unit 140 uses W(z) based on the acquired disturbance signal w(n) or the acquired W(z) to remove W(z) contained in D(z). Specifically, the control unit 140 removes W(z) as shown in equation (8). The W(z) on the far right of equation (8) is W(z) based on the acquired disturbance signal w(n) or the acquired W(z).

[0044]

[0045] In this way, the control unit 140 can cancel out the noise indicated by the disturbance signal w(n).

[0046] The control unit 140 performs feedforward control using D(z) in equation (8). Except for the use of D(z) in equation (8), the feedforward control is performed in the same manner as in the prior art.

[0047] The control unit 140 may determine the timing to use the disturbance signal w(n) based on the sound pressure when the elevator car 10 starts to move. The control unit 140 may also determine the timing to use the disturbance signal w(n) based on an electrical signal obtained from a speed sensor or acceleration sensor installed in the elevator car 10.

[0048] Next, graphs are shown for a case where the control device 100 does not perform control to cancel out noise based on the disturbance signal w(n) and a case where the control device 100 performs control to cancel out noise based on the disturbance signal w(n).

[0049] 5A and 5B are graphs showing coherence in the first embodiment. The vertical axis of FIGS. 5A and 5B represents coherence. The horizontal axis of FIGS. 5A and 5B represents frequency. FIG. 5A is a graph showing the case where the control device 100 does not perform control to cancel noise based on the disturbance signal w(n). FIG. 5B is a graph showing the case where the control device 100 performs control to cancel noise based on the disturbance signal w(n). The closer the value is to "1," the higher the coherence. As shown in the graphs of FIG. 5, the graph of FIG. 5B has higher coherence than the graph of FIG. 5A.

[0050] FIG. 6 is a graph showing the amount of noise reduction in the first embodiment. The vertical axis of FIG. 6 represents the amount of noise reduction. The horizontal axis of FIG. 6 represents time. Graph 21 is a graph for the case where the control device 100 does not perform control to cancel out noise based on the disturbance signal w(n). Graph 22 is a graph for the case where the control device 100 performs control to cancel out noise based on the disturbance signal w(n). As shown in FIG. 5, when the control device 100 performs control to cancel out noise based on the disturbance signal w(n), coherence is high. Therefore, the amount of noise reduction is also high.

[0051] According to the first embodiment, the control device 100 can prevent a decrease in coherence by canceling out noise based on the disturbance signal. Furthermore, the method of the first embodiment does not change the configuration of the duct 11. Therefore, the first embodiment can be realized at low cost. Furthermore, as shown in equation (8), the first embodiment can be realized by simply removing the disturbance signal. Therefore, the system does not become complicated.

[0052] Variation 1 of Embodiment 1 In the first embodiment, a case where noise such as inherent vibrations and motor noise is input to the error microphone 300 has been described. When the elevator car 10 is moving, the noise may be input to the reference microphone 200. When the noise is input to the reference microphone 200, coherence decreases. Therefore, in Variation 1 of Embodiment 1, a case where the control device 100 prevents the decrease in coherence will be described.

[0053] First, the process up to when the disturbance signal w(n) is stored in the control device 100 will be described. The identification unit 120 calculates W(z) based on a sound signal of a sound recorded while the elevator car 10 is moving and noise based on the disturbance signal w(n) is input to the reference microphone 200. Note that the sound of the sound signal is a sound recorded while the speaker 400 is not outputting sound. Specifically, the identification unit 120 calculates W(z) by converting equation (9). That is, W(z) is expressed by equation (10). Note that P(z) in equations (9) and (10) is P(z) calculated by equation (1).

[0054]

[0055] This allows the identifying unit 120 to identify the disturbance signal w(n).

[0056] The identification unit 120 stores the disturbance signal w(n) in the memory unit 110. When the disturbance signal w(n) is stored in the memory unit 110, the identification unit 120 performs an inverse z-transform on W(z) and stores the disturbance signal w(n) obtained by the inverse z-transform in the memory unit 110. The identification unit 120 may also store W(z) in the memory unit 110. Here, the disturbance signal w(n) is also referred to as a second disturbance signal. In other words, the disturbance signal w(n) is noise generated by the movement of the elevator car 10 and is a sound signal of the noise input to the reference microphone 200. W(z) is also referred to as a second z-transformed disturbance signal obtained by z-transforming the disturbance signal w(n). In this way, the disturbance signal w(n) is stored in the control device 100.

[0057] Next, a case will be described in which the disturbance signal w(n) stored in the storage unit 110 is used. The acquisition unit 130 acquires the disturbance signal w(n) or W(z) from the storage unit 110. This acquisition process is also referred to as a second acquisition process.

[0058] When the elevator car 10 is moving and noise based on a disturbance signal is input to the reference microphone 200, the control unit 140 performs control to cancel the noise using the acquired disturbance signal w(n) or W(z). This sentence can also be expressed as follows: When the elevator car 10 is moving and noise based on a disturbance signal is input to the reference microphone 200, the control unit 140 performs control to cancel the noise using the acquired disturbance signal w(n) or W(z), and also performs feedforward control of noise sound in the duct 11 of the elevator car 10 using the reference microphone 200, the error microphone 300, and the speaker 400. The control will be described in detail below.

[0059] When the disturbance signal w(n) is acquired, the control unit 140 performs z-transform on the disturbance signal w(n), thereby obtaining W(z).

[0060] When elevator car 10 is moving and speaker 400 is driven, X(z) is expressed by equation (11).

[0061]

[0062] As shown in equation (11), X(z) contains W(z). Therefore, the control unit 140 uses W(z) based on the acquired disturbance signal w(n) or the acquired W(z) to remove W(z) contained in X(z). Specifically, the control unit 140 removes W(z) as shown in equation (12). The W(z) on the far right of equation (12) is W(z) based on the acquired disturbance signal w(n) or the acquired W(z).

[0063]

[0064] In this way, the control unit 140 can cancel the noise represented by the disturbance signal w(n). The control unit 140 performs feedforward control using X(z) in equation (12). Except for the use of X(z) in equation (12), the feedforward control is performed in the same manner as in the prior art.

[0065] According to the first modification of the first embodiment, the control device 100 can prevent a decrease in coherence by canceling out the noise based on the disturbance signal w(n).

[0066] Modification 2 of Embodiment 1 Noise such as inherent vibration or motor sound may be input to the reference microphone 200 and the error microphone 300. In such cases, coherence decreases. Therefore, in Modification 2 of Embodiment 1, a case will be described in which the control device 100 prevents the decrease in coherence.

[0067] First, a description will be given of the process up to when the disturbance signal is stored in the control device 100. The identification unit 120 calculates W based on the sound signal of the sound recorded while the elevator car 10 is moving and noise based on the disturbance signal is input to the reference microphone 200 and the error microphone 300. １ (z) and W ２ The sound of the sound signal is recorded when the speaker 400 is not outputting sound. １ (z) is the disturbance signal w of the noise input to the reference microphone 200 １ (n) shows the z-transform of W ２ (z) is the noise disturbance signal w input to the error microphone 300２ The z-transform of (n) is shown below. The calculation method will be specifically explained. D(z) when the elevator car 10 is moving is expressed by equation (13). Note that P(z) is P(z) calculated by equation (1).

[0068]

[0069] The determination unit 120 solves the optimization problem shown in equation (14) to determine W １ (z) and W ２ (z) is calculated.

[0070]

[0071] G(z) is expressed by equation (15).

[0072]

[0073] b is expressed by equation (16).

[0074]

[0075] Furthermore, the specifying unit 120 １ (z) and W ２ (z) and W are perturbed by heuristic solutions. １ (z) and W ２ (z) may be calculated.

[0076] The determination unit 120 determines the disturbance signal w １ (n) and disturbance signal w ２ (n) is stored in the storage unit 110. １ When (n) is stored in the storage unit 110, the identification unit 120 １ (z) is subjected to inverse z-transformation, and the disturbance signal w obtained by the inverse z-transformation is １ (n) is stored in the storage unit 110. ２ When (n) is stored in the storage unit 110, the identification unit 120 ２ (z) is subjected to inverse z-transformation, and the disturbance signal w obtained by the inverse z-transformation is ２ (n) is stored in the storage unit 110. １ (z) and W ２ (z) may be stored in the storage unit 110. Here, the disturbance signal w１ (n) is also called the second disturbance signal. １ (z) is the disturbance signal w １ (n) is also called the second z-transformed disturbance signal expressed by z-transform. ２ (n) is also called the first disturbance signal. ２ (z) is the disturbance signal w ２ (n) is also called the first z-transformed disturbance signal expressed by z-transform. １ (n) and disturbance signal w ２ (n) are stored in the control device 100.

[0077] Next, the disturbance signal w stored in the memory unit 110 １ (n) and disturbance signal w ２ The case where (n) is used will be described. １ (n) and disturbance signal w ２ (n), or W １ (z) and W ２ (z) is acquired from the storage unit 110. This acquisition process is also referred to as a third acquisition process.

[0078] When the elevator car 10 is moving and noise based on a disturbance signal is input to the reference microphone 200 and the error microphone 300, the control unit 140 calculates the obtained disturbance signal w １ (n) and disturbance signal w ２ (n), or W １ (z) and W ２ (z) to perform control to cancel the noise. This sentence can also be expressed as follows: When the elevator car 10 is moving and the noise is input to the reference microphone 200 and the error microphone 300, the control unit 140 uses the acquired disturbance signal w １ (n) and disturbance signal w ２ (n), or W １ (z) and W ２ (z) is used to perform control to cancel out the noise, and the reference microphone 200, the error microphone 300, and the speaker 400 are used to perform feedforward control of the noise sound in the duct 11 of the elevator car 10. The control will be described in detail below.

[0079] Disturbance signal w １ When (n) is acquired, the control unit 140 calculates the disturbance signal w １ (n) is z-transformed. As a result, the control unit 140 obtains W １ (z) can be obtained. The disturbance signal w ２ When (n) is acquired, the control unit 140 calculates the disturbance signal w ２ (n) is z-transformed. As a result, the control unit 140 obtains W ２ When the elevator car 10 is moving and the speaker 400 is driven, X(z) can be obtained by the following equation (17).

[0080]

[0081] As shown in equation (17), X(z) contains W １ Therefore, the control unit 140 calculates the disturbance signal w １ W based on (n) １ (z), or the obtained W １ (z), W included in X(z) １ Specifically, the control unit 140 removes W １ (z) is removed. W on the right side of equation (18) １ (z) is the acquired disturbance signal w １ W based on (n) １ (z), or the obtained W １ (z).

[0082]

[0083] When elevator car 10 is moving and speaker 400 is driven, D(z) is expressed by equation (19).

[0084]

[0085] As shown in equation (19), D(z) includes W ２ Therefore, the control unit 140 uses the disturbance signal w (z) stored in the storage unit 110. ２ W based on (n) ２ (z), or W stored in the storage unit 110２ (z), W included in D(z) ２ Specifically, the control unit 140 removes W ２ (z) is removed. W on the right side of equation (20) ２ (z) is the disturbance signal w stored in the memory unit 110 ２ W based on (n) ２ (z), or W stored in the storage unit 110 ２ (z).

[0086]

[0087] In this way, the control unit 140 detects the disturbance signal w １ (n) and disturbance signal w ２ The noise indicated by (n) can be cancelled out.

[0088] The control unit 140 performs feedforward control using X(z) in equation (18) and D(z) in equation (20). Except for the use of X(z) in equation (18) and D(z) in equation (20), the feedforward control is performed in the same manner as in the prior art.

[0089] According to the second modification of the first embodiment, the control device 100 detects the disturbance signal w １ (n) and disturbance signal w ２ By canceling out the noise based on (n), it is possible to prevent the decrease in coherence.

[0090] Second Embodiment Next, a second embodiment will be described. In the second embodiment, differences from the first embodiment will be mainly described. Furthermore, in the second embodiment, descriptions of the commonalities between the first embodiment and the second embodiment will be omitted.

[0091] 7 is a diagram illustrating an example of a control system according to embodiment 2. The control system includes a control device 100, a reference microphone 200, error microphones 300_1, ..., 300_n, and a speaker 400, where n is a positive integer.

[0092] As shown in FIG. 7 , the control system includes multiple error microphones. The control device 100 is connected to the multiple error microphones via a network. When the elevator car 10 is moving and noise based on the disturbance signal w(n) is input to the multiple error microphones, the control unit 140 uses beamforming (BF) to control the multiple error microphones so that their directivities are directed toward the noise sound in the duct 11. This allows the control device 100 to prevent noise based on a disturbance signal that has not been measured in advance (i.e., a disturbance signal other than the disturbance signal w(n)) from being input to the multiple error microphones. Note that the beamforming may be delay-and-sum beamforming, MVDR (Minimum Variance Distortionless Response) beamforming, or Griffith-Jim beamforming.

[0093] The control system may include multiple reference microphones. The control device 100 is connected to the multiple reference microphones via a network. When the elevator car 10 is moving and noise based on the disturbance signal w(n) is input to the multiple reference microphones, the control unit 140 controls the multiple reference microphones using beamforming to orient the directivity of the multiple reference microphones toward the direction of the noise sound in the duct 11. This allows the control device 100 to prevent noise based on a disturbance signal that has not been measured in advance (i.e., a disturbance signal other than the disturbance signal w(n)) from being input to the multiple reference microphones. Note that, for example, when the multiple reference microphones are arranged in a line and there are two reference microphones, x(n) is expressed by equation (21).

[0094]

[0095] The control system may include multiple reference microphones and multiple error microphones. The control device 100 is connected to the multiple reference microphones and the multiple error microphones via a network. The control unit 140 receives a disturbance signal w from the multiple reference microphones and the multiple error microphones while the elevator car 10 is moving. １ (n) and disturbance signal w２ When noise based on (n) is input, the control device 100 controls the reference microphones and the error microphones using beamforming so that the direction of the directivity of the error microphones and the direction of the directivity of the reference microphones are directed in the direction of the noise sound in the duct 11. As a result, the control device 100 detects a disturbance signal (i.e., disturbance signal w １ Disturbance signals other than (n) and disturbance signal w ２ It is possible to prevent noise based on disturbance signals other than (n) from being input to the multiple reference microphones and the multiple error microphones.

[0096] The embodiments are merely examples, and various modifications are possible within the scope of the present disclosure. Furthermore, the features of the embodiments can be combined with each other as appropriate.

[0097] 10 elevator car, 11 duct, 21 graph, 22 graph, 100 control device, 101 processor, 102 volatile storage device, 103 non-volatile storage device, 110 storage unit, 120 identification unit, 130 acquisition unit, 140 control unit, 200 reference microphone, 300, 300_1, ..., 300_n error microphone, 400 speaker.

Claims

1. A control device that is connected to a reference microphone, an error microphone, and a speaker and performs active noise control, comprising: a memory unit; an acquisition unit that acquires from the memory unit either or both of a first disturbance signal, which is a signal of noise generated by the movement of an elevator car and collected by the error microphone, obtained from a sound signal collected by the error microphone while the elevator car is moving, and a second disturbance signal, which is a signal of noise generated by the movement of the elevator car and collected by the reference microphone, obtained from a sound signal collected by the reference microphone while the elevator car is moving; and a control unit, wherein when the first disturbance signal is acquired, the control unit uses the first disturbance signal to control canceling out the noise collected by the error microphone from the signal collected by the error microphone while the elevator car is moving, and when the second disturbance signal is acquired, the control unit uses the second disturbance signal to control canceling out the noise collected by the reference microphone from the signal collected by the reference microphone while the elevator car is moving. Control device.

2. The control device described in claim 1, wherein the acquisition unit acquires from the memory unit the first disturbance signal or a first z-transformed disturbance signal that is a z-transform of the first disturbance signal, and the control unit, when the elevator car is moving and the noise is input to the error microphone, performs control to cancel out the noise using the first disturbance signal or the first z-transformed disturbance signal.

3. The control device according to claim 2, wherein the control device is connected to a plurality of error microphones, and the control unit uses beamforming to control the plurality of error microphones so that the direction of their directivity is directed toward the direction of noise sound within the duct of the elevator car.

4. The control device described in claim 1, wherein the acquisition unit acquires from the memory unit the second disturbance signal or a second z-transformed disturbance signal expressed by z-transforming the second disturbance signal, and the control unit, when the elevator car is moving and the noise is input to the reference microphone, performs control to cancel out the noise using the second disturbance signal or the second z-transformed disturbance signal.

5. The control device according to claim 4, wherein the control device is connected to a plurality of reference microphones, and the control unit uses beamforming to control the plurality of reference microphones so that the direction of the directivity of the plurality of reference microphones is directed in the direction of noise sound within the duct of the elevator car.

6. The control device described in claim 1, wherein the acquisition unit acquires from the memory unit the first disturbance signal and the second disturbance signal, or a first z-transformed disturbance signal expressed by z-transforming the first disturbance signal and a second z-transformed disturbance signal expressed by z-transforming the second disturbance signal, and the control unit, when the elevator car is moving and the noise is input to the reference microphone and the error microphone, performs control to cancel out the noise using the first disturbance signal and the second disturbance signal, or the first z-transformed disturbance signal and the second z-transformed disturbance signal.

7. The control device according to claim 6, wherein the control device is connected to a plurality of error microphones and a plurality of reference microphones, and the control unit uses beamforming to control the plurality of error microphones and the plurality of reference microphones so that the directivity directions of the plurality of error microphones and the directivity directions of the plurality of reference microphones are directed in the direction of noise sound within the duct of the elevator car.

8. A control method in which a control device connected to a reference microphone, an error microphone, and a speaker, which performs active noise control, and which has a memory unit, acquires from the memory unit either or both of a first disturbance signal, which is a signal of noise generated by the movement of an elevator car and picked up by the error microphone, obtained from a sound signal picked up by the error microphone while the elevator car is moving, and a second disturbance signal, which is a signal of noise generated by the movement of the elevator car and picked up by the reference microphone, obtained from a sound signal picked up by the reference microphone while the elevator car is moving; when the first disturbance signal is acquired, uses the first disturbance signal to perform control to cancel out the noise picked up by the error microphone from the signal picked up by the error microphone while the elevator car is moving; and when the second disturbance signal is acquired, uses the second disturbance signal to perform control to cancel out the noise picked up by the reference microphone from the signal picked up by the reference microphone while the elevator car is moving.

9. A control program that causes a control device that is connected to a reference microphone, an error microphone, and a speaker, performs active noise control, and has a memory unit to execute a process of acquiring from the memory either or both of a first disturbance signal, which is a signal of noise generated by the movement of an elevator car and picked up by the error microphone, obtained from a sound signal picked up by the error microphone while the elevator car is moving, and a second disturbance signal, which is a signal of noise generated by the movement of the elevator car and picked up by the reference microphone, obtained from a sound signal picked up by the reference microphone while the elevator car is moving; when the first disturbance signal is acquired, the control program uses the first disturbance signal to cancel out the noise picked up by the error microphone from the signal picked up by the error microphone while the elevator car is moving; and when the second disturbance signal is acquired, the control program uses the second disturbance signal to cancel out the noise picked up by the reference microphone from the signal picked up by the reference microphone while the elevator car is moving.

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