EP4023848A1

EP4023848A1 - Abnormality detecting device, program, abnormality detecting method, and information processing device

Info

Publication number: EP4023848A1
Application number: EP21197123.9A
Authority: EP
Inventors: Shogo KIGAMI
Original assignee: Nabtesco Corp
Current assignee: Nabtesco Corp
Priority date: 2020-09-16
Filing date: 2021-09-16
Publication date: 2022-07-06
Also published as: CN114263410A; JP2022049691A

Abstract

An abnormality detecting device (1) for detecting an abnormality of at least one rotating body, the at least one rotating body being configured to transmit power generated by an actuator to open and close a door (3R, 3L), the abnormality detecting device (1) including: an obtaining unit (31) for obtaining, during movement of the door (3R, 3L), a door operation signal related to at least one of opening operation or closing operation of the door (3R, 3L); and a determination unit (32) for determining whether or not the door operation signal includes a periodic component according to a rotational period of the at least one rotating body.

Description

TECHNICAL FIELD

One embodiment of the present invention relates to an abnormality detecting device, a program, an abnormality detecting method, and an information processing device.

BACKGROUND

An automatic door includes mechanism parts formed of a plurality of rotating bodies such as a door roller or a pinion gear. Examples of the rotating bodies include a door roller moving on a rail and a pinion gear rotating with teeth meshing with teeth of another rotating body. For a door roller, as the contact surface with the rail wears, the smoothness of the rotation may be deteriorated. For a gear such as a pinion gear, the teeth may break and come out of mesh with the other gear, resulting in a reduced rotational force. In this way, the rotating bodies undergo breakage and wear due to aging degradation or the like, and thus maintenance work is required to replace parts as necessary.
When a rotating body breaks or wears, the rotational force is no longer transmitted normally, which may result in a change in the speed of the door or the motor current. To overcome this problem, a device has been proposed that monitors the speed of the door or the motor current and, when a predetermined threshold value is exceeded, determines that some kind of abnormality has occurred and hastens the maintenance work (see Japanese Patent Application Publication No. 2011-11715 ).
However, an automatic door includes a plurality of rotating bodies, and it is difficult to ascertain whether each of the rotating bodies is broken or worn. The condition of the rotating bodies cannot be grasped unless the mechanism parts including the rotating bodies are detached and disassembled. It is thus a drawback that when an abnormality occurs in operation of an automatic door due to a fault in the rotating bodies, time is taken to identify the cause.
One embodiment of the present invention provides an abnormality detecting device, a program, an abnormality detecting method, and an information processing device capable of detecting an abnormality of a rotating body in a simple and accurate manner.

SUMMARY

To overcome the above drawback, one embodiment of the present invention provides an abnormality detecting device for detecting an abnormality of at least one rotating body, the at least one rotating body being configured to transmit power generated by an actuator to open and close a door, the abnormality detecting device comprising: an obtaining unit for obtaining, during movement of the door, a door operation signal related to at least one of opening operation or closing operation of the door; and a determination unit for determining whether or not the door operation signal includes a periodic component according to a rotational period of the at least one rotating body.
It is also possible that the actuator includes a motor for driving the door, and the door operation signal includes at least one of an electric current flowing through the motor, an opening or closing speed of the door, or vibration of the door.
It is also possible that the at least one rotating body comprises a plurality of rotating bodies having different rotational radii, and the abnormality detecting device includes an identifying unit, and when the determination unit has determined that the door operation signal includes the periodic component, the identifying unit identifies, from among the plurality of rotating bodies, a rotating body which has the periodic component based on the rotational radii of the plurality of rotating bodies.
It is also possible that the identifying unit identifies, from among the plurality of rotating bodies, a rotating body which has the periodic component based on at least one of the rotational radii of the plurality of rotating bodies, a speed instruction for the door, temperatures around the plurality of rotating bodies, an accumulated operation time of the door, or a number of times of opening and closing operation of the door.
It is also possible that the abnormality detecting device includes a first storage unit for storing information on rotational periods of the plurality of rotating bodies, and when the determination unit has determined that the door operation signal includes the periodic component, the identifying unit refers to the information stored on the first storage unit to identify the rotating body.
It is also possible that the determination unit determines whether or not the door operation signal includes the periodic component based on a result of comparison between the door operation signal and a reference signal, the reference signal being related to at least one of the opening operation or the closing operation performed when the rotating body has no abnormality.
It is also possible that the determination unit determines whether or not a difference signal between the door operation signal and the reference signal includes the periodic component.
It is also possible that the abnormality detecting device includes a second storage unit for storing the reference signal, and the determination unit refers to the reference signal stored on the second storage unit to determine whether or not the door operation signal includes the periodic component.
It is also possible that the determination unit compares the door operation signal with the reference signal within a time period in which the door is moving at a constant speed, to determine whether or not the door operation signal includes the periodic component.
It is also possible that the determination unit compares the door operation signal with the reference signal within a time period in which a signal level of the door operation signal is constant, to determine whether or not the door operation signal includes the periodic component.
It is also possible that the door operation signal includes a speed signal of the door, and the determination unit compares the door operation signal with the reference signal within a time period for a constant speed region of the door in which a signal level of the speed signal is constant, to determine whether or not the door operation signal includes the periodic component.
It is also possible that within a time period in which the door is moving at a constant acceleration, the determination unit corrects a difference signal between the door operation signal and the reference signal with the constant acceleration, and determines whether or not the corrected signal includes the periodic component.
It is also possible that the abnormality detecting device includes a first generating unit for generating the reference signal based on at least one of a speed instruction for the door, temperatures around the plurality of rotating bodies, accumulated operation time of the door, or a number of times of opening and closing operation of the door.
It is also possible that the determination unit determines whether or not the door operation signal includes the periodic component when a difference signal between the door operation signal and the reference signal exceeds a threshold value.
It is also possible that the difference signal between the door operation signal and the reference signal is a time-series signal, and the determination unit converts the difference signal into a frequency-series signal by Fourier transform and determines whether or not the door operation signal includes the periodic component corresponding to a frequency occurring when the frequency-series signal exceeds the threshold value.
It is also possible that the abnormality detecting device includes a second generating unit configured to cause the door to open and close immediately after the door is installed or immediately after a maintenance work of the door is completed, to generate the reference signal.
It is also possible that the obtaining unit obtains the door operation signal when the door is first opened or closed after a power supply is started or restarted.
It is also possible that the abnormality detecting device includes an outputting unit for outputting an indication that the determination unit has determined that the door operation signal includes the periodic component.
Another aspect of the present invention provides a program for detecting an abnormality of at least one rotating body, the at least one rotating body being configured to transmit power generated by an actuator to a door, the program causing a computer to: obtain a door operation signal related to at least one of opening operation or closing operation of the door; and determine whether or not the door operation signal includes a periodic component according to a rotational period of the at least one rotating body, based on the door operation signal and a reference signal.
Another aspect of the present invention provides a method for detecting an abnormality of at least one rotating body, the at least one rotating body being configured to transmit power generated by an actuator to a door, the method comprising: obtaining a door operation signal related to at least one of opening operation or closing operation of the door; and determining whether or not the door operation signal includes a periodic component according to a rotational period of the at least one rotating body, based on the door operation signal and a reference signal.
Another aspect of the present invention provides an information processing device for detecting an abnormality of at least one rotating body, the at least one rotating body being configured to transmit power generated by an actuator to a door, the information processing device comprising: a receiving unit for receiving a door operation signal related to at least one of opening operation or closing operation of the door; and a determination unit for determining whether or not the door operation signal includes a periodic component according to a rotational period of the at least one rotating body, based on the door operation signal and a reference signal.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is an external view showing an electric door device having an abnormality detecting device relating to one embodiment built therein.
Fig. 2 more specifically shows the constituents parts in the vicinity of a motor.
Fig. 3 is a block diagram schematically showing the configuration of a control system of the electric door device of Fig. 1.
Fig. 4 is a block diagram showing an example of the internal configuration of the abnormality detecting device.
Fig. 5A is a signal waveform diagram showing an example of a door operation signal obtained by an obtaining unit.
Fig. 5B is a signal waveform diagram showing an example of a reference signal.
Fig. 6A is a signal waveform diagram showing an example of a difference signal including an abnormality signal.
Fig. 6B is a signal waveform diagram showing an example of a difference signal not including an abnormality signal.
Fig. 7 is a flow chart showing an example of operation of the abnormality detecting device relating to the embodiment.
Fig. 8 is a block diagram schematically showing the configuration of an information processing device including the electric door device.

DETAILED DESCRIPTION OF THE EMBODIMENTS

With reference to the drawings, a description will be hereinafter given of an embodiment of an abnormality detecting device, a program, an abnormality detecting method, and an information processing device. The following focuses on the main constituent parts of the abnormality detecting device, the program, the abnormality detecting method, and the information processing device, but the abnormality detecting device, the program, the abnormality detecting method, and the information processing device may include more constituent parts not shown and functions not described. The following description exclude by no means such constituent parts not shown and functions not described.
Fig. 1 is an external view showing an electric door device 2 having an abnormality detecting device 1 relating to one embodiment built therein. The electric door device 2 shown in Fig. 1 is designed to be installed in railway vehicles. The electric door device 2 according to the present embodiment can be used in a wide range of applications in addition to railroad vehicles. For example, the electric door device 2 relating to the present embodiment are applicable to automatic door devices installed in vehicles, buildings and facilities, and also to doors of private residences. The electric door device 2 described herein is installed mainly in railway vehicles.
The electric door device 2 shown in Fig. 1 includes a pair of door leaves 3R and 3L constituting a sliding door. The door leaves 3R and 3L are movable in the left-right direction in the drawing. Above the door leaves 3R and 3L, a guide rail 4, a suspension device 5R supporting the right door leaf 3R, and a suspension device 5L supporting the left door leaf 3L are provided.
The suspension device 5R and the door leaf 3R are integrally movable along the guide rail 4. Likewise, the suspension device 5L and door leaf 3L are integrally movable along the guide rail 4. As used herein, the term "door" may refer to at least one of the door leaf 3R or the door leaf 3L.
In the suspension devices 5R and 5L, a plurality of rollers 6 are provided, as shown by the dotted lines in Fig. 1. The rollers 6 roll while remaining in contact with the upper or lower surface of the guide rail 4.
The leading edge of the door leaves 3R and 3L has a front rubber 7 attached thereto, which is made of a soft synthetic rubber material. When the door leaves 3R and 3L are fully closed, their respective front rubbers 7 touch each other and contract to a certain extent while touching each other, before the door leaves 3R and 3L stop moving.
Above the guide rail 4, a right rack gear 8R and a left rack gear 8L are provided and extend in the direction in which the guide rail 4 extends. The right rack gear 8R is coupled with a right bracket 9R. As the right rack gear 8R moves in the left-right direction, the movement causes the right bracket 9R to move in the left-right direction. Similarly, the left rack gear 8L is coupled with a left bracket 9L. As the left rack gear 8L moves in the left-right direction, the movement causes the left bracket 9L to move in the left-right direction. The right bracket 9R is coupled with the suspension device 5R. As the right bracket 9R moves in the left-right direction, the suspension device 5R and door leaf 3R integrally move in the left-right direction. Similarly, the left bracket 9L is coupled with the suspension device 5L. As the left bracket 9L moves in the left-right direction, the suspension device 5L and door leaf 3L integrally move in the left-right direction.
The right and left rack gears 8R and 8L mesh with a pinion gear 10, so that they are configured to convert the rotation of the pinion gear 10 into linear movement. The pinion gear 10 is rotated when acted upon by driving force from a motor 11.
Fig. 2 more specifically shows the constituent parts in the vicinity of the motor 11. A sun gear 13 is attached to a rotational shaft 12 of the motor 11, a plurality of planetary gears 14 surround and mesh with the sun gear 13, and the pinion gear 10 is positioned outside the planetary gears 14 and serves as an outer gear meshing with the planetary gears 14.
With the above-described configuration, as the motor 11 rotates, the resulting rotational force is transmitted to the rack gears 8R and 8L via the pinion gear 10. As the rack gears 8R and 8L move in the left-right direction as a result of the rotation of the motor 11, the door leaves 3R and 3L move in the left-right direction along the guide rail 4 via the right and left brackets 9R and 9L. The motor 11 is driven by a motor driving unit 23 included in a controller 15 shown in Fig. 3, which will be described below.
In the above description, the electric door device 2 may be opened or closed using the rack and pinion system, but the present disclosure is not necessarily limited to such. Any other systems (for example, belt, screw and linear motor systems) may be employed.
Fig. 3 is a block diagram schematically showing the configuration of a control system of the electric door device 2 of Fig. 1. The control system of the electric door device 2 relating to the present embodiment includes a controller 15, a power supply unit 16, and a motor monitoring unit 17. The controller 15 has an abnormality detecting device 1 provided therein.
The power supply unit 16 includes a power unit for converting an alternating-current voltage fed from an overhead line into a direct-current voltage. The controller 15 includes a door opening-closing control unit 18 and an instructing unit 19, in addition to the abnormality detecting device 1. In accordance with an instruction from a managing device (not shown), the instructing unit 19 outputs, to the door opening-closing control unit 18, an instruction signal for opening or closing the door leaves 3R and 3L. The door opening-closing control unit 18 controls the opening or closing of the door leaves 3R and 3L based on the instruction signal.
The door opening-closing control unit 18 includes a power-supply voltage detecting unit 21, a PWM control unit 22, a motor driving unit 23 and a Hall signal detector 24.
The power-supply voltage detecting unit 21 is configured to detect the level of the DC voltage output from the power supply unit 16. The PWM control unit 22 is configured to generate a PWM signal for driving the motor 11 based on the level of the DC voltage detected by the power-supply voltage detecting unit 21 and the instruction signal from the instructing unit 19. More specifically, the PWM control unit 22 generates the PWM signal for controlling the duty ratio of the voltage to be fed to the motor 11, based on a reference voltage instruction pattern indicated by the instruction signal and the voltage level of the DC signal detected by the power-supply voltage detecting unit 21.
The motor driving unit 23 is configured to turn on or off the transistors configured to drive the motor 11, based on the PWM signal. For example, when the motor 11 is a three-phase motor, the motor driving unit 23 generates gate signals for turning on or off the U-phase, V-phase and W-phase transistors.
A Hall element 25 is provided in the vicinity of the rotational shaft 12 of the motor 11. The Hall element 25 detects the number of rotations of the motor 11. In the vicinity of the motor 11, the motor monitoring unit 17 is provided. The motor monitoring unit 17 includes, in addition to the above-mentioned Hall element 25, a motor current detector 26 for detecting the motor current and a motor voltage detector 27 for detecting the voltage applied to the motor 11.
The Hall signal detector 24 is configured to detect the number of rotations of the motor 11 based on the detection signal from the Hall element 25. The motor driving unit 23 can refer to the number of rotations of the motor 11 detected by the Hall signal detector 24 to feedback control the timing of turning on or off the transistors for driving the motor 11.
The electric door device 2 relating to the present embodiment may include a sending unit 28. The sending unit 28 is configured to, if the abnormality detecting device 1 detects an abnormality of a rotating body, notify a managing device (not shown), a mobile terminal carried by a maintenance worker or the like of the fact that the abnormality of the rotating body has been detected.
The abnormality detecting device 1 detects abnormalities in various rotating bodies used in the electric door device 2. Examples of the abnormality in the rotating bodies include chip or wear of a part of teeth in the case of gears. When the electric door device 2 is of a belt-type, wear of a pulley attached to the belt may be a cause of the abnormality in the rotating bodies. Further, when the electric door device 2 is of a screw-type, breakage of a nut may be a cause of the abnormality in the rotating bodies. The specific types of the rotating bodies are not limited but may be, for example, the rollers 6 shown in Fig. 1, and the sun gear 13, the planetary gears 14, and the pinion gear 10 provided in the vicinity of the rotational shaft 12 of the motor 11.
Fig. 4 is a block diagram showing an example of the internal configuration of the abnormality detecting device 1. As shown in Fig 4, the abnormality detecting device 1 includes an obtaining unit 31 and a determination unit 32.
The obtaining unit 31 obtains, during the movement of the door leaves, a door operation signal related to at least one of the opening operation or closing operation of the door leaves 3R and 3L. The door operation signal includes, for example, at least one of the speed of the door leaves 3R and 3L, the vibration of the door leaves 3R and 3L, or the electric current of the motor 11. The door operation signal is a time-series signal obtained continuously for a predetermined period of time.
The determination unit 32 determines whether or not the door operation signal includes a periodic component according to the rotational period of a rotating body. Each of the various rotating bodies provided in the electric door device 2 has its characteristic periodic component. For example, a gear having a plurality of teeth has a periodic component according to the rotational radius, the number of teeth, and the rotational period of the gear. A rotating body not having teeth, such as the rollers 6, has a periodic component according to the rotational radius and the rotational period of the rotating body itself. For example, when a rotating body is rotating at a constant rotational speed, the period of the periodic component included in the door operation signal is longer as the rotating radius is larger, and the period of the periodic component is shorter as the number of the teeth is larger. In addition, the period of the periodic component included in the door operation signal is longer as the rotational period of the rotating body is longer. The periodic component included in the door operation signal is significant when any of the rotating bodies related to the door operation signal has an abnormality. Specifically, when none of the rotating bodies has an abnormality, the door operation signal does not include a periodic component, and when at least one of the rotating bodies has an abnormality, the door operation signal includes the periodic component characteristic of the rotating body having the abnormality. In order to identify the rotating body having an abnormality, the determination unit 32 determines whether or not the door operation signal includes a periodic component.
Since the door operation signal may include noise signals in addition to the periodic component according to the rotational period of the rotating body, it may be difficult to extract the periodic component directly from the door operation signal. Therefore, for example, the determination unit 32 may perform Fourier transform on the door operation signal, which is a time-series signal, to convert it into a frequency-series signal, compare the frequency-series signal with a predetermined threshold value, and when the threshold value is exceeded, determine that the door operation signal includes a periodic component corresponding to the frequency exceeding the threshold value.
As will be described later, when the determination unit 32 determines that the door operation signal includes a periodic component, it is determined that the rotating body having the periodic component has an abnormality.
The determination unit 32 may sort various rotating bodies provided in the electric door device 2. Among them, each set of two or more rotating bodies having the same rotational period may be sorted into one group, and it may be determined for each group whether or not its periodic component is included in the door operation signal.
The abnormality detecting device 1 relating to the present embodiment may include an identifying unit 33, in addition to the obtaining unit 31 and the determination unit 32. When the determination unit 32 has determined that the door operation signal includes a periodic component, the identifying unit 33 identifies, from among a plurality of rotating bodies, a rotating body which has this periodic component based on the rotational radii of the plurality of rotating bodies. The identified rotating body probably has an abnormality. The reason that the identifying unit 33 considers the rotational radii of the plurality of rotating bodies to identify the periodic component is that different rotational radii result in different rotational periods of the rotating bodies.
The identifying unit 33 may identify, from among a plurality of rotating bodies, a rotating body which has the above periodic component based on at least one of the rotational radii of the plurality of rotating bodies, the speed instruction for the door, the temperatures around the plurality of rotating bodies, the accumulated door operation time, or the number of times of opening and closing operation of the door. The reason that the identifying unit 33 considers the speed instruction for the door is that different rotational speeds of the rotating bodies result in different rotational periods of the rotating bodies. The reason that the temperatures around the plurality of rotating bodies are considered is that a change in temperature causes a rotating body to expand or contract, resulting in a change in the rotational radius and thus a change in the rotational period. In addition, a change in temperature may also cause a change in coefficient of friction of the rotating bodies and thus a change in the rotational speed. The reason that the accumulated door operation time or the number of times of opening and closing operation of the door is considered is that, as the accumulated operation time or the number of times of opening and closing operation is larger, the difference in degree of breakage or wear between the rotating bodies may be larger, resulting in different rotational periods. The speed instruction for the door may be either issued from the managing device via the instructing unit 19 or issued from the motor driving unit 23 with a motor driving signal.
Thus, in the present embodiment, the various rotating bodies provided in the electric door device 2 are not directly inspected for presence of an abnormality, but the determination unit 32 determines whether or not the door operation signal includes a periodic component, making it possible to easily identify the rotating body having an abnormality.
The abnormality detecting device 1 relating to the present embodiment may include an outputting unit 34 for outputting a determination result of the determination unit 32. The outputting unit 34 outputs an indication that the determination unit 32 has determined that the door operation signal includes a periodic component. The outputting unit 34 may output information on the rotating body identified by the identifying unit 33. The information output from the outputting unit 34 may be sent by the sending unit 28 shown in Fig. 3 to a mobile phone carried by a maintenance worker or to the managing device (not shown) managing the electric door device 2.
The abnormality detecting device 1 relating to the present embodiment may include a first storage unit 35. The first storage unit 35 stores information on the rotational periods of the rotating bodies. For example, the first storage unit 35 stores previously investigated information on the rotational periods of the various rotating bodies provided in the electric door device 2. As described above, the rotational period of a gear having a plurality of teeth changes in accordance with the number of teeth and the rotational speed. Therefore, the first storage unit 35 may store information on the rotational periods of the rotating bodies for each combination of the number of teeth and the rotational speed.
Further, since the rotational periods of the rotating bodies may also change depending on the temperatures around the rotating bodies, the accumulated door operation time, or the number of times of the opening and closing operation of the door, the first storage unit 35 may previously store information on the rotational periods of the rotating bodies in association with at least one of the temperatures around the rotating bodies, the accumulated door operation time, or the number of times of the opening and closing operation of the door. In this case, a rotational period of a rotating body can be read from the first storage unit 35 by inputting to the first storage unit 35 the current temperature around the rotating body, the current accumulated door operation time, and the current number of times of opening and closing operation of the door as input parameters. The information on a rotational period of a rotating body stored on the first storage unit 35 is, for example, a value of a periodic component of the rotating body. The first storage unit 35 is a non-volatile memory or a non-volatile storage device. Information once stored on the first storage unit 35 is retained until it is updated later, even if the power supply of the electric door device 2 is turned off, and therefore, it is favorable that there is no need of refreshing the stored information.
Suppose that the abnormality detecting device 1 includes the first storage unit 35. When the determination unit 32 determines that a periodic component is included, the identifying unit 33 refers to the information stored on the first storage unit 35 and identifies the rotating body having the rotational period corresponding to the periodic component. Specifically, the identifying unit 33 searches the first storage unit 35 to find the information on the rotating body having the same or similar periodic component as that included in the door operation signal, thereby identifying the rotating body having the periodic component included in the door operation signal in a simple and accurate manner.
As described above, the door operation signal includes at least one of the speed of the door leaves 3R and 3L, the vibration of the door leaves 3R and 3L, or the electric current of the motor 11, and the signal level of the door operation signal may vary in accordance with time. Therefore, it is possible that the determination unit 32 cannot easily determine whether or not the door operation signal includes a periodic component according to the rotational period of a rotating body.
To overcome this problem, the determination unit 32 may compare the door operation signal with a reference signal. More specifically, the determination unit 32 may determine whether or not the door operation signal includes a periodic component based on a result of comparison between the door operation signal and a reference signal related to at least one of opening operation or closing operation performed when the rotating body has no abnormality. In this case, the determination unit 32 may determine whether or not the difference signal between the door operation signal and the reference signal includes a periodic component. For example, suppose that the door operation signal relates to the speed of the door leaves 3R and 3L. Since the reference signal related to the speed also vary in accordance with time, the difference signal between the door operation signal related to the speed and the reference signal may be obtained to extract only the periodic component related to the rotational period of the rotating body having an abnormality. Therefore, the determination unit 32 can easily perform the determination process. In addition, since the difference signal may also include noise signals, it is also possible to perform Fourier transform on the difference signal, which is a time-series signal, to convert it into a frequency-series signal, compare the frequency-series signal with a threshold value, and determine that the door operation signal includes a periodic component corresponding to the frequency exceeding the threshold value, as described above.
In this way, each of various rotating bodies provided in the electric door device 2 has its characteristic periodic component, and when an abnormality occurs in any of the rotating bodies, an abnormality signal according to the periodic component of this rotating body is superposed on the door operation signal. Since the difference signal between the door operation signal and the reference signal includes mainly the abnormality signal mentioned above, the rotating body having the abnormality can be identified by detecting the periodic component in the difference signal.
The abnormality detecting device 1 relating to the present embodiment may include a second storage unit 36 that stores the reference signal mentioned above. The reference signal is the door operation signal obtained when the various rotating bodies provided in the electric door device 2 are operating normally, and the reference signal can be generated previously. For example, it can be presumed that all the rotating bodies are operating normally immediately after the electric door device 2 is installed or immediately after maintenance work is completed. Therefore, the reference signal may be generated immediately after installation and then stored on the second storage unit 36. The timing referred to by the phrase "immediately after" is, for example, before the operation of the electric door device 2 is started or resumed. Since the reference signal stored on the second storage unit 36 is then used repeatedly, the second storage unit 36 is preferably a non-volatile memory or a non-volatile storage device.
In the opening and closing operation, the speed of the door leaves 3R and 3L are not necessarily constant. When moved from the full open position toward the closed position, the door leaves 3R and 3L are typically first accelerated in the acceleration region, then the door leaves 3R and 3L are moved at a constant speed in the constant speed region, and the door leaves 3R and 3L are decelerated in the deceleration region close to the closed position.
In the acceleration region and the deceleration region of the door leaves 3R and 3L, the door leaves 3R and 3L are prone to be affected by disturbance. Therefore, the determination unit 32 may compare the door operation signal with the reference signal within the time period in which the door leaves are moving at a constant speed (the constant speed region), thereby determining whether or not the door operation signal includes a periodic component.
Further, if the door operation signal and the reference signal are compared when the signal level of the door operation signal is varying, the difference signal is prone to be affected by noise and the like. Therefore, the determination unit 32 may compare the door operation signal with the reference signal within the time period in which the signal level of the door operation signal is constant, thereby determining whether or not the door operation signal includes a periodic component.
For example, when the door operation signal includes a speed signal related to the speed of the door leaves 3R and 3L, the determination unit 32 may compare the door operation signal with the reference signal within the time period for the constant speed region of the door in which the signal level of the speed signal is constant, thereby determining whether or not the door operation signal includes a periodic component.
When moved from the full open position toward the closed position, the door leaves 3R and 3L are moved at a constant acceleration in the acceleration region, then the door leaves 3R and 3L are moved at a constant speed in the constant speed region, and the door leaves 3R and 3L are moved at a constant acceleration in the deceleration region. The determination unit 32 may determine whether or not the door operation signal includes a periodic component in at least one of the acceleration region or the deceleration region, in addition to the constant speed region. In the acceleration region and the deceleration region, the door leaves 3R and 3L move at a constant acceleration. Therefore, in at least one of the acceleration region or the deceleration region, the determination unit corrects the difference signal between the door operation signal and the reference signal with the constant acceleration of the door leaves 3R and 3L, and determines whether or not the corrected signal includes a periodic component. More specifically, when a rotating body has an abnormality, the door operation signal includes a signal component in which the periodic component of the rotating body varies at a constant acceleration. This signal component can be divided by the constant acceleration to obtain the inherent periodic component of the rotating body having the abnormality.
The abnormality detecting device 1 relating to the present embodiment may include a first generating unit 37. The first generating unit 37 generates a reference signal based on at least one of the speed instruction for the door leaves 3R and 3L, the temperatures around the rotating bodies, the accumulated operation time of the door leaves 3R and 3L, or the number of times of opening and closing operation. For example, the first generating unit 37 causes the door leaves 3R and 3L to open and close immediately after installation of the electric door device 2, and detect the speed of the door leaves 3R and 3L during the opening or closing operation to generate the reference signal, or obtain the temperatures around the rotating bodies to generate the reference signal based on these temperatures. The reason that the speed instruction for the door leaves 3R and 3L is considered in generating the reference signal is that when the moving speed of the door leaves 3R and 3L changes, the rotational speeds of the rotating bodies change, and the rotational periods also change in accordance with the rotational speeds. The reason that the temperatures around the rotating bodies are considered is that a change in temperature causes the rotating bodies to expand or contract, resulting in a change in the rotational radius and thus a change in the rotational period. In addition, a change in temperature may also cause a change in coefficient of friction of the rotating bodies and thus a change in the rotational speed. The reason that the accumulated door operation time or the number of times of opening and closing operation of the door is considered is that, as the accumulated operation time or the number of times of opening and closing operation is larger, the difference in degree of breakage or wear between the rotating bodies may be larger, resulting in different rotational periods.
In comparing the door operation signal with the reference signal, the determination unit 32 may determine whether or not the door operation signal includes a periodic component when the difference signal between the door operation signal and the reference signal exceeds a threshold value. With the use of the threshold value, less impact is applied by the disturbance such as noises. As described above, the difference signal is a time-series signal. In comparing the difference signal formed of a time-series signal with the threshold value, a time region in which the difference signal has a higher signal level than the threshold value is extracted, and it is determined whether or not the difference signal in the extracted time region includes a periodic component. This makes it possible to remove noise signals having a smaller signal level than the threshold value and determine whether or not the difference signal includes a periodic component. If the difference signal has a complex waveform due to noises included in the difference signal, it may be impossible to accurately determine whether or not the difference signal includes a periodic component. Therefore, as described above, it is preferable that the difference signal is first converted into a frequency-series signal and then compared with the threshold value. In this case, the frequency exceeding the threshold value forms the periodic component included in the difference signal. Further, the difference signal is an alternating signal that varies in the positive direction and the negative direction relative to the predetermined reference signal level, and therefore, the difference signal needs to be compared with the threshold value in consideration of the polarity of the difference signal. For example, it is possible to compare the absolute value of the difference signal with the threshold value or to perform the comparison using a first threshold value for comparison with the positive difference signal and a second threshold value for comparison with the negative difference signal.
The abnormality detecting device 1 relating to the present embodiment may include a second generating unit 38. The second generating unit 38 causes the door leaves 3R and 3L to open and close immediately after the door leaves 3R and 3L are installed or immediately after the maintenance work is completed, to generate the reference signal. The reference signal generated is preferably stored on the second storage unit 36. When the second storage unit 36 already stores a reference signal, the reference signal is preferably updated with the new reference signal.
In a case where the electric door device 2 is used in railways, some passengers lean on the door leaves 3R and 3L or are pushed against the door leaves 3R and 3L due to the crowded situation. Because of impact of these disturbances, the door leaves 3R and 3L may undergo an unintended load, and the speed of the door leaves 3R and 3L may be varied.
To avoid the disturbances caused by the passengers, it is preferable that the processes of the obtaining unit 31 and the determination unit 32 are performed before departure of the railway vehicle, when it carries no passenger, or after the maintenance work is completed but before the railway vehicle carries passengers.
As shown in Fig. 3, the abnormality detecting device 1 of the embodiment may be connected to or include a temperature detector 39. The temperature detector 39 detects temperatures around the rotating bodies. The reason that the temperature detector 39 is provided is that the door operation signal may be affected by the temperatures. For example, the second storage unit 36 described above may store a plurality of different reference signals for different temperatures. The reason that a plurality of different reference signals are stored for different temperatures is that a change in temperature causes a rotating body to expand or contract, resulting in a change in the rotational radius and causing the rotational period of the rotating body to be shifted from an expected value. In addition, a change in temperature may cause a change in viscosity of a grease provided on the rotational shaft of a rotating body, resulting in a change in the coefficient of friction of the rotating body and causing the rotational period to be shifted from an expected value. In this case, the second storage unit 36 stores a plurality of reference signals in association with a plurality of temperatures, and the determination unit 32 reads out from the second storage unit 36 the reference signal associated with the temperature detected by the temperature detector 39 and obtain the difference signal between the door operation signal and the reference signal. In this way, the determination unit 32 can determine whether or not the door operation signal includes a periodic component in consideration of the temperatures around the rotating bodies.
As shown in Fig. 3, the abnormality detecting device 1 of the embodiment may be connected to or include a vibration detector 40. The vibration detector 40 detects vibration generated when the door leaves 3R and 3L are moving. If any of the rotating bodies included in the electric door device 2 has an abnormality, rotation of this rotating body may cause rattling, resulting in vibration of the door leaves 3R and 3L. When the door operation signal includes vibration detected by the vibration detector 40, the rotating body having the abnormality can be identified by the vibration period of the vibration.
Fig. 5A is a signal waveform diagram showing an example of a door operation signal obtained by the obtaining unit 31, and Fig. 5B is a signal waveform diagram showing an example of the reference signal. In Figs. 5A and 5B, the horizontal axes indicate time, and the vertical axes indicate the signal level of the door operation signal or the reference signal. The door operation signal and the reference signal shown in Figs. 5A and 5B are, for example, the speed signals of the door leaves 3R and 3L.
When the door leaves 3R and 3L are moved from the full open position toward the closed position, the speed signal of the door leaves 3R and 3L include the acceleration region, the constant speed region, and the deceleration region. When any of the plurality of rotating bodies included in the electric door device 2 has an abnormality, an abnormality signal appears that is formed of a periodic component not included in the proper speed signal, as in the signal projection portion shown in Fig. 5A.
The determination unit 32 compares the door operation signal of Fig. 5A with the reference signal of Fig. 5B to obtain a difference signal between these signals. The difference signal includes only the abnormality signal having such a signal waveform as shown in Fig. 6A. In this way, the difference between the door operation signal and the reference signal is obtained to remove the reference signal component included in the door operation signal, leaving the abnormality signal including only the periodic component of the rotating body having the abnormality. The difference signal of Fig. 6A includes the abnormality signal formed of the periodic component of the rotating body having the abnormality, but the periodic component of this abnormality signal does not necessarily have regular periods. As shown in Fig. 6A, when the door operation signal includes the speed signal, the abnormality signal included in the difference signal includes a periodic component having a constant frequency in the constant speed region, but the frequency of the periodic component varies in the acceleration region and the deceleration region.
Therefore, the determination unit 33 refers to the periodic component corresponding to the constant speed region of the door leaves 3R and 3L indicated by the broken line in Fig. 6A and identifies the rotating body having the same or similar periodic component. Alternatively, as described above, the abnormality signal in the acceleration region and the deceleration region may be corrected with the acceleration of the door leaves 3R and 3L to generate a periodic component having a constant frequency.
When all the rotating bodies included in the electric door device 2 are operating normally, the door operation signal has the same signal waveform as the reference signal shown in Fig. 5B. Therefore, the difference signal between the door operation signal and the reference signal obtained by the determination unit 32 includes no periodic component, as in the signal shown in Fig. 6B (zero level).
Fig. 7 is a flow chart showing an example of operation of the abnormality detecting device 1 relating to the embodiment. First, the temperature is detected by the temperature detector 39 (step S1), and the reference signal associated with the detected temperature is selected from the second storage unit 36 (step S2). It is not essential to select the reference signal associated with the temperature. It is also possible that the second storage unit 36 stores a reference signal independent of the temperature, and this reference signal is read out from the second storage unit 36.
Next, the door operation signal is obtained by the obtaining unit 31 (step S3). Next, the difference signal between the door operation signal and the reference signal is generated by the determination unit 32 (step S4).
Next, it is determined whether or not the difference signal exceeds a threshold value (step S5). The processing of step S5 may be omitted, but if the difference signal includes a noise component, comparison with the threshold value reduces the impact of the noise included in the difference signal. In addition, since the difference signal is a time-series signal, as described above, the difference signal may be converted into a frequency-series signal by Fourier transform before the comparison with the threshold value.
If the difference signal is equal to or less than the threshold value, it is determined that none of the rotating bodies has an abnormality (step S6), and the process of Fig. 7 is ended. On the other hand, if the difference signal exceeds the threshold value in any time region, the periodic component is detected based on the time region in which the difference signal exceeds the threshold value (step S7). In the case where the difference signal is converted into a frequency-series signal before the comparison with the threshold value, the frequency of the frequency-series signal exceeding the threshold value is detected as the periodic component.
Next, it is determined whether or not the information on the rotating body having the same or similar periodic component as that included in the difference signal is stored on the first storage unit 35 (step S8). As described above, the first storage unit 35 previously stores, for each of the plurality of rotating bodies, the information indicating the value of its characteristic rotational period. In step S8, it is determined whether or not the first storage unit 35 stores the information on the rotating body having a rotational period corresponding to the period of the difference signal detected in step S7. In comparing the values of the rotational periods of the rotating bodies stored on the first storage unit 35 with the value obtained from the periodic component included in the difference signal, it is possible to set a certain degree of error margin, and if a rotating body has a value within the error margin, it can be determined that the first storage unit 35 stores the corresponding information. When the first storage unit 35 stores the corresponding information, it is determined that this rotating body has an abnormality, and the information on this rotating body is output (step S9). If it is determined in step S8 that the first storage unit 35 does not store the corresponding information on the rotating body, the information on the periodic component included in the difference signal is output (step S10).
The information output in step S9 or S10 may be sent via the sending unit 28 to a managing device or a mobile terminal carried by a maintenance worker.
The determination unit 32 in the abnormality detecting device 1 shown in Fig. 3 may be included in a managing device 42, such as a server, connected to a network 41. Fig. 8 is a block diagram schematically showing the configuration of an information processing device 43 including the electric door device 2. The information processing device 43 of Fig. 8 includes the electric door device 2 and the managing device 42 that communicate various information over the network 41.
The electric door device 2 in Fig. 8 has the same block configuration as in Fig. 1. However, the internal configuration of the abnormality detecting device 1 in the electric door device 2 is partly different from that shown in Fig. 4. More specifically, the determination unit 32, which was provided in the abnormality detecting device 1 of Fig. 4, is provided in the managing device 42. The managing device 42 includes a receiving unit 30, in addition to the determination unit 32. The receiving unit 30 receives via the sending unit 28 the door operation signal obtained by the obtaining unit 31 in the abnormality detecting device 1. The determination unit 32 determines whether or not the door operation signal received by the receiving unit 30 includes a periodic component.
It is also possible that the managing device 42 includes the identifying unit 33, the first storage unit 35, the second storage unit 36, the first generating unit 37, and the second generating unit 38 shown in Fig. 4. Since the managing device 42 includes a CPU (central processing unit) having a higher performance than the electric door device 2, the determination process can be performed at a higher speed than it is performed by the determination unit 32 in the electric door device 2.
The determination result obtained by the determination unit 32 in the managing device 42 may be either communicated to the electric door device 2 over the network 41 or sent to the mobile terminal carried by the maintenance worker.
As described above, the electric door device 2 includes various rotating bodies, and each of the rotating bodies has its characteristic frequency component. When any of the rotating bodies has some kind of abnormality, the signal level of the door operation signal is varied at a period characteristic of this rotating body. Therefore, in the embodiment, the abnormality of the rotating body can be detected quickly by determining whether or not the door operation signal includes a periodic component. In particular, when it is determined whether or not the difference signal between the door operation signal and the reference signal includes the periodic component, the abnormality of the rotating body can be detected quickly and accurately without being affected by disturbances.
In the embodiment, the abnormality of any rotating body can be detected by determining whether or not the door operation signal includes a periodic component, without directly inspecting the various rotating bodies included in the electric door device 2. Therefore, it is possible to easily identify the rotating body having the abnormality and thus reduce the labor of the maintenance worker.
At least some of the constituent parts of the abnormality detecting device 1 and the information processing device 43 described in the above embodiments may be implemented through hardware or software. If the software is used, at least some of the functions of the abnormality detecting device and the information processing device are implemented by a program, and the program may be stored on a storage medium such as a flexible disc and a CD-ROM and executed when read by a computer. The storage medium is not limited to detachable ones such as magnetic and optical discs, and may be stationary storage media such as hard disk devices and memory devices.
Alternatively, at least some of the functions of the abnormality detecting device and the information processing device may be implemented by a program, and the program may be distributed through communication lines (including wireless communication) such as the Internet. Furthermore, the program may be encrypted, modulated or compressed to be distributed through wired or wireless lines such as the Internet or on storage media.
Aspects of the present invention are not limited to the foregoing embodiments and embrace various modifications conceivable to those skilled in the art. Effects of the present invention are also not limited to the above-mentioned contents. That is, various additions, changes, and partial deletions are possible in a range not departing from the conceptual ideas and spirit of the present invention derived from contents defined in the claims and equivalents thereof.

Claims

An abnormality detecting device (1) for detecting an abnormality of at least one rotating body, the at least one rotating body being configured to transmit power generated by an actuator to open and close a door (3R, 3L), the abnormality detecting device (1) comprising:
an obtaining unit (31) for obtaining, during movement of the door (3R, 3L), a door operation signal related to at least one of opening operation or closing operation of the door (3R, 3L); and

a determination unit (32) for determining whether or not the door operation signal includes a periodic component according to a rotational period of the at least one rotating body.
The abnormality detecting device (1) according to claim 1,
wherein the actuator includes a motor (11) for driving the door (3R, 3L), and

wherein the door operation signal includes at least one of an electric current flowing through the motor (11), an opening or closing speed of the door (3R, 3L), or vibration of the door (3R, 3L).
The abnormality detecting device (1) according to claim 1,
wherein the at least one rotating body comprises a plurality of rotating bodies having different rotational radii, and

wherein the abnormality detecting device (1) includes an identifying unit (33), and when the determination unit (32) has determined that the door operation signal includes the periodic component, the identifying unit (33) identifies, from among the plurality of rotating bodies, a rotating body which has the periodic component based on the rotational radii of the plurality of rotating bodies.
The abnormality detecting device (1) according to claim 3, wherein the identifying unit (33) identifies, from among the plurality of rotating bodies, a rotating body which has the periodic component based on at least one of the rotational radii of the plurality of rotating bodies, a speed instruction for the door (3R, 3L), temperatures around the plurality of rotating bodies, an accumulated operation time of the door (3R, 3L), or a number of times of opening and closing operation of the door (3R, 3L).
The abnormality detecting device (1) according to claim 3 or 4, further comprising:
a first storage unit (35) for storing information on rotational periods of the plurality of rotating bodies,

wherein when the determination unit (32) has determined that the door operation signal includes the periodic component, the identifying unit (33) refers to the information stored on the first storage unit (35) to identify the rotating body.
The abnormality detecting device (1) according to any one of claims 1 to 5, wherein the determination unit (32) determines whether or not the door operation signal includes the periodic component based on a result of comparison between the door operation signal and a reference signal, the reference signal being related to at least one of the opening operation or the closing operation performed when the rotating body has no abnormality.
The abnormality detecting device (1) according to claim 6, wherein the determination unit (32) determines whether or not a difference signal between the door operation signal and the reference signal includes the periodic component.
The abnormality detecting device (1) according to claim 6 or 7, further comprising:
a second storage unit (36) for storing the reference signal,

wherein the determination unit (32) refers to the reference signal stored on the second storage unit (36) to determine whether or not the door operation signal includes the periodic component.
The abnormality detecting device (1) according to any one of claims 6 to 8, wherein the determination unit (32) compares the door operation signal with the reference signal within a time period in which the door (3R, 3L) is moving at a constant speed, to determine whether or not the door operation signal includes the periodic component.
The abnormality detecting device (1) according to any one of claims 6 to 8, wherein the determination unit (32) compares the door operation signal with the reference signal within a time period in which a signal level of the door operation signal is constant, to determine whether or not the door operation signal includes the periodic component.
The abnormality detecting device (1) according to claim 9 or 10,
wherein the door operation signal includes a speed signal of the door (3R, 3L), and

wherein the determination unit (32) compares the door operation signal with the reference signal within a time period for a constant speed region of the door (3R, 3L) in which a signal level of the speed signal is constant, to determine whether or not the door operation signal includes the periodic component.
The abnormality detecting device (1) according to any one of claims 6 to 8, wherein within a time period in which the door is moving at a constant acceleration, the determination unit (32) corrects a difference signal between the door operation signal and the reference signal with the constant acceleration, and determines whether or not the corrected signal includes the periodic component.
The abnormality detecting device (1) according to any one of claims 6 to 12, further comprising:
a first generating unit (37) for generating the reference signal based on at least one of a speed instruction for the door (3R, 3L), temperatures around the plurality of rotating bodies, accumulated operation time of the door (3R, 3L), or a number of times of opening and closing operation of the door (3R, 3L).
The abnormality detecting device (1) according to any one of claims 6 to 13, wherein the determination unit (32) determines whether or not the door operation signal includes the periodic component when a difference signal between the door operation signal and the reference signal exceeds a threshold value.
The abnormality detecting device (1) according to claim 14,
wherein the difference signal between the door operation signal and the reference signal is a time-series signal, and

wherein the determination unit (32) converts the difference signal into a frequency-series signal by Fourier transform and determines whether or not the door operation signal includes the periodic component corresponding to a frequency occurring when the frequency-series signal exceeds the threshold value.
The abnormality detecting device (1) according to any one of claims 6 to 15, further comprising:
a second generating unit (38) configured to cause the door (3R, 3L) to open and close immediately after the door (3R, 3L) is installed or immediately after a maintenance work of the door (3R, 3L) is completed, to generate the reference signal.
The abnormality detecting device (1) according to any one of claims 1 to 16, wherein the obtaining unit (31) obtains the door operation signal when the door (3R, 3L) is first opened or closed after a power supply is started or restarted.
The abnormality detecting device (1) according to any one of claims 1 to 17, further comprising:
an outputting unit (34) for outputting an indication that the determination unit (32) has determined that the door operation signal includes the periodic component.
A program for detecting an abnormality of at least one rotating body, the at least one rotating body being configured to transmit power generated by an actuator to a door (3R, 3L), the program causing a computer to:
obtain a door operation signal related to at least one of opening operation or closing operation of the door (3R, 3L); and

determine whether or not the door operation signal includes a periodic component according to a rotational period of the at least one rotating body, based on the door operation signal and a reference signal.
A method for detecting an abnormality of at least one rotating body, the at least one rotating body being configured to transmit power generated by an actuator to a door (3R, 3L), the method comprising:
obtaining a door operation signal related to at least one of opening operation or closing operation of the door (3R, 3L); and

determining whether or not the door operation signal includes a periodic component according to a rotational period of the at least one rotating body, based on the door operation signal and a reference signal.
An information processing device (43) for detecting an abnormality of at least one rotating body, the at least one rotating body being configured to transmit power generated by an actuator to a door (3R, 3L), the information processing device (43) comprising:
a receiving unit (30) for receiving a door operation signal related to at least one of opening operation or closing operation of the door (3R, 3L); and

a determination unit (32) for determining whether or not the door operation signal includes a periodic component according to a rotational period of the at least one rotating body, based on the door operation signal and a reference signal.