Door motor anomaly detection device

Abstract

This improves the accuracy of anomaly detection in elevator systems using multiple door motors, without adding any new components. [Solution] The door motor abnormality detection device according to the embodiment is an abnormality detection device for a door motor in an elevator system that uses multiple motors to open and close the doors of the elevator car. The door motor abnormality detection device according to the embodiment has a position sensor, a time measurement unit, a storage unit, and an abnormality detection unit. The position sensor detects the open or closed state of the door. The time measurement unit measures the door open time or door closed time. The storage unit stores the door open time or door closed time when the door motor is functioning normally as a reference time. The abnormality detection unit determines whether or not there is an abnormality in the door motor by comparing the door open time or door closed time measured by the time measurement unit with the reference time each time the door is opened or closed.

Description

Technical Field

[0001] Embodiments of the present invention relate to an abnormality detection device for a door motor.

Background Art

[0002] The door of an elevator car is opened and closed by the driving force of a door motor. In a large elevator, since the weight of the door is large, the driving force may be increased by connecting two door motors in parallel. The two door motors are connected in parallel in order to convert the rotation of the two door motors into the force for opening and closing the door via a chain or the like. Therefore, even if one of the door motors has an open-circuit fault, the door can be opened and closed if the other door motor is operating normally.

[0003] However, when one of the door motors has an open-circuit fault, a large load is applied to the healthy door motor, so the load on the healthy door motor increases and an overcurrent flows. Therefore, the healthy door motor will have its lifespan reduced in a short time and the risk of failure increases. If the healthy door motor fails before the repair of the open-circuit-fault door motor is completed, there is a possibility that passengers may be trapped inside the car.

[0004] If the current supplied to each of the two door motors is measured, it is possible to detect whether any of the door motors has failed. However, ammeters are often provided on the inverter power supply side, which is the current supply source, and generally the current supplied to each of the two door motors is not measured.

[0005] Techniques for diagnosing the soundness of a door, including foreign object entrapment, based on the output current of an inverter power supply or the torque of a door motor have been reported. However, no report has been found on a technique for detecting that one of the two door motors has failed.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2007-168989 [Patent Document 2] International Publication No. 2020 / 021630 [Overview of the project] [Problems that the invention aims to solve]

[0007] This invention was made in response to the circumstances described above, and aims to improve the accuracy of anomaly detection in elevator systems using multiple door motors without adding any new parts. [Means for solving the problem]

[0008] The door motor abnormality detection device according to the embodiment for solving the above problems is a door motor abnormality detection device in an elevator system that uses multiple motors to open and close the doors of the elevator car. The door motor abnormality detection device according to the embodiment has a position sensor, a time measurement unit, a storage unit, and an abnormality detection unit. The position sensor detects the open or closed state of the door. The time measurement unit measures the door open time or door closed time. The storage unit stores the door open time or door closed time when the door motor is functioning normally as a reference time. The abnormality detection unit determines whether or not there is an abnormality in the door motor by comparing the door open time or door closed time measured by the time measurement unit with the reference time each time the door is opened or closed. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view of the elevator device according to this first embodiment. [Figure 2] This is a block diagram showing the control system of an elevator device according to the first embodiment. [Figure 3] This is a block diagram of the drive unit according to this embodiment 1. [Figure 4] This is a block diagram of the control unit according to this embodiment 1. [Figure 5]This is a flowchart illustrating the abnormality detection process by the elevator abnormality detection device according to this embodiment 1. [Figure 6] This is a block diagram of the control unit according to this second embodiment. [Figure 7] This is a flowchart illustrating the abnormality detection process by the elevator abnormality detection device according to this second embodiment. [Figure 8] This figure illustrates the abnormality detection method used by the abnormality detection device according to this second embodiment. [Modes for carrying out the invention]

[0010] This embodiment will be described below with reference to the drawings. For the purpose of this description, an XYZ coordinate system consisting of mutually orthogonal X, Y, and Z axes will be used as appropriate. The figures and flowcharts used in this description are examples only.

[0011] (Embodiment 1) Figure 1 is a perspective view of the elevator system 10 according to this embodiment. The elevator system 10 is located inside a hoistway 11 installed in a building such as a commercial facility or residential facility. As shown in Figure 1, the elevator system 10 includes an elevator car 31, a counterweight 35, a lifting motor 40, a control panel 70 (elevator control device), and the like.

[0012] The elevator car 31 is a unit that accommodates passengers and moves up and down the elevator shaft 11. The elevator car 31 is positioned between the guide rails and is mounted so as to be movable in the vertical direction relative to the guide rails 21-24.

[0013] An opening 31a for entering and exiting the elevator car 31 is formed on the +X side. The opening 31a is closed or opened by a pair of doors 32 that move along the side of the elevator car 31. The doors 32 are opened and closed by door motors (not shown in Figure 1). The elevator car 31 is equipped with multiple position sensors 38 that detect the open or closed position of the doors 32.

[0014] The counterweight 35 is attached to the guide rails 21 to 24 so as to be movable in the vertical direction. The weight of the counterweight 35 is adjusted to a predetermined ratio with respect to the weight of the car 31.

[0015] The hoist motor 40 is a motor for raising and lowering the car 31. The hoist motor 40 is arranged at the upper part of the hoistway 11 such that the rotation axis is parallel to the Y axis. A pulley 42 is fixed to the rotation axis of the hoist motor 40. A wire 43 is wound around the pulley 42 of the hoist motor 40. One end of the wire 43 is fixed to the car 31, and the other end is fixed to the counterweight 35.

[0016] The control panel 70 is arranged in the hoistway 11. The control panel 70 houses a control device for controlling the hoist motor 40 and the devices provided in the car 31. In the following embodiments, a machine-room-less elevator in which the control panel 70 is arranged in the hoistway 11 will be described as an example, but this embodiment can also be applied to the case where there is a machine room.

[0017] FIG. 2 is a block diagram showing the control system of the elevator apparatus 10. The control system includes a control unit 80 and a drive unit 90 housed in the control panel 70, an operation panel 36 provided in the car 31, and a plurality of position sensors 38.

[0018] The operation panel 36 is provided on the inner wall surface of the car 31. The operation panel 36 is an interface for receiving the destination floor and the like from the users of the car 31. The users can register the destination floor of the car 31 and open and close the door 32 by operating the operation panel 36.

[0019] The position sensor 38 is a sensor that detects the door-open state or door-closed state of the door 32. A plurality of position sensors 38 are provided in the vicinity of the rail that guides the door 32. For example, the position sensor 38 is composed of a position sensor 381 that detects that the door 32 is in a completely closed state and a position sensor 383 that detects that the door 32 is in a completely open state. When the door 32 is composed of a pair of doors, the position sensor 381 and the position sensor 383 are provided corresponding to the left and right doors.

[0020] The control unit 80 has a control unit 801 for the lifting motor and a control unit 802 for the door motor. The drive unit 90 drives the lifting motor 40 and the door motor 41 by supplying power to the lifting motor 40 and a door motor 41 (not shown in FIG. 1) that drives the door 32 of the car 31. The drive unit 90 drives the lifting motor 40 based on an instruction from the control unit 801 for the lifting motor. Also, the drive unit 90 drives the door motor 41 based on an instruction from the control unit 802 for the door motor.

[0021] Figure 3 is a block diagram of the drive unit 90. The drive unit 90 has a converter 91 and a converter 93. A smoothing capacitor 92 is provided between the converter 91 and the converter 93. When the door motor 41 is a DC motor, the converter 93 is a chopper circuit that performs DC-to-DC conversion, and when the door motor 41 is an AC motor, it becomes an inverter that performs DC-to-AC conversion. In Figure 3, the door motor 41 is described in detail using a DC motor, so the converter 93 is a chopper circuit. However, the same applies even if the door motor 41 is an AC motor and the converter 93 is an inverter, in which case a three-phase configuration is used and three wires are connected to the door motor 41. The converter 91 converts the AC power of the commercial power supply 1 into power suitable for the converter 93. The converter 93 is a power supply device that supplies power to the lifting motor 40 and the door motor 41. The converter 93 is composed of a switching regulator. When the lifting motor 40 and the door motor 41 are formed by three-phase AC motors, the converter 93 outputs a three-phase AC voltage. The output of the converter 93 is equipped with an ammeter 95 that measures the power supplied to the lifting motor 40 and the door motor 41. Note that the lifting motor 40 is not shown in Figure 3. The doors 32 are not opened or closed while the elevator car 31 is being raised or lowered. Therefore, the ammeter 95 measures the current supplied to the lifting motor 40 while the elevator car 31 is being raised or lowered, and measures the current supplied to the door motor 41 when the doors 32 are being opened or closed.

[0022] Multiple motors are used in the door motor 41 that opens and closes the door 32 of the elevator car 31. Figure 3 shows the case where two door motors, door motor DM1 and door motor DM2, are connected in parallel. The rotational force of door motors DM1 and DM2 is converted into a force that opens and closes the door 32 via a chain or the like. Since door motors DM1 and DM2 are connected in parallel, even if one door motor fails due to a broken wire, the door 32 can still be opened and closed as long as the other door motor is functioning properly. The ammeter 95 measures the total value of the current supplied to the two door motors, door motor DM1 and door motor DM2, but does not measure the current supplied to door motor DM1 and door motor DM2 individually.

[0023] Returning to Figure 2, the control unit 80 is a computer having a CPU, main memory, auxiliary memory, and interface unit. The CPU executes the processes described later according to the program stored in the auxiliary memory. The main memory has RAM, etc. The main memory is used as the CPU's workspace. The auxiliary memory has non-volatile memory such as ROM and semiconductor memory. The auxiliary memory stores the program executed by the CPU and various parameters. The auxiliary memory also stores data on the door opening time and door closing time of the door 32 when the two door motors are in good condition, and data on the current supplied to the door motor 41 (the sum of the current supplied to the two door motors, door motor DM1 and door motor DM2) when the two door motors are in good condition.

[0024] The interface unit includes serial interfaces, parallel interfaces, and wireless LAN interfaces. The operation panel 36 and the drive unit 90 are connected to the CPU via the interface unit. An input / output device 100, consisting of a keyboard, display, etc., is also connected to the interface unit.

[0025] Figure 4 is a functional block diagram of the control unit 80. The CPU of the control unit 80 executes a program stored in the auxiliary memory to realize the drive unit control unit 71 and the abnormality detection device 72.

[0026] The drive unit control unit 71 controls the drive unit 90 based on input from the operation panel 36 or the call panel on each floor. For example, when the drive unit control unit 71 rotates the lift motor 40 forward via the drive unit 90, the elevator car 31 rises and the counterweight 35 lowers. When the drive unit control unit 71 rotates the lift motor 40 backward via the drive unit 90, the elevator car 31 lowers and the counterweight 35 rises. Also, when the drive unit control unit 71 rotates the door motor 41 forward via the drive unit 90, the doors 32 of the elevator car 31 and the doors provided at each floor landing are opened, and when the door motor 41 is rotated backward, the doors 32 of the elevator car 31 and the doors provided at each floor landing are closed.

[0027] The abnormality detection device 72 is a device that detects abnormalities in the door motor 41. The abnormality detection device 72 has a time measurement unit 721, a storage unit 722, and an abnormality detection unit 723.

[0028] The time measurement unit 721 is a device that measures the door open time and door closed time of the door 32. Here, we will describe the case in which two position sensors 38 are provided for one side of the door 32. Position sensor 381 is a position sensor that detects the position in which the door 32 is completely closed. Position sensor 383 is a position sensor that detects the position in which the door 32 is completely open. When position sensors 381 and 383 detect a predetermined part of the door 32 (for example, the edge of the door), they transmit, for example, a pulse signal.

[0029] The time measurement unit 721 includes a timer. The timer measures the time (door closing time) from when the drive unit control unit 71 issues a door closing command to the door motor 41 via the drive unit 90 while the door 32 is in the open state until the position sensor 381 detects that the door has become closed. The timer also measures the time (door opening time) from when the drive unit control unit 71 issues a door opening command to the door motor 41 via the drive unit 90 while the door 32 is in the closed state until the position sensor 383 detects that the door has become open.

[0030] The memory unit 722 stores the door opening time and door closing time of the two door motors, door motor DM1 and door motor DM2, as reference times when they are functioning normally.

[0031] The abnormality detection unit 723 determines whether there is an abnormality in the door motor 41 by comparing the door opening time and door closing time measured by the time measurement unit 721 with a reference time each time the door 32 is opened and closed. Specifically, the abnormality detection unit 723 determines that there is an abnormality in the door motor 41 if the difference between the door opening time and door closing time measured by the time measurement unit 721 each time the door 32 is opened and closed with a reference time stored in the storage unit 722 is greater than or equal to a predetermined value.

[0032] When the abnormality detection unit 723 detects an abnormality, it outputs a notification to the input / output device 100 indicating that an abnormality has occurred. The abnormality detection unit 723 also notifies the drive unit control unit 71 that an abnormality has occurred. Upon receiving notification of an abnormality, the drive unit control unit 71 controls the drive unit 90 to open and close the doors 32 of the elevator car 31 in safety mode. Safety mode is an operation (opening / closing control) in which the opening and closing acceleration and speed of the doors 32 are reduced compared to normal operation. In addition, in safety mode operation, the door open holding current and door closed holding current are suppressed to hold the doors 32 open or closed. In order to hold the doors 32 in the open position, a predetermined force must be applied to the doors 32. The door open holding current is the current that flows to the door motor 41 in order to apply this predetermined force. Similarly, in order to hold the doors 32 in the closed position, a predetermined force must be applied to the doors 32. The door closed holding current is the current that flows to the door motor 41 in order to apply this predetermined force. Since the door 32 remains in either the closed or open position for an extended period, suppressing the holding current can reduce the lifespan degradation of the healthy door motor 41.

[0033] Next, the abnormality detection process of the elevator device 10 will be explained with reference to the flowchart shown in Figure 5. The following control is performed based on a program stored in the auxiliary storage unit, and the main control unit is the control unit 80 (CPU). The door opening time and door closing time of the door 32 when the door motor 41 is functioning normally are stored as reference times in the storage unit 722.

[0034] The abnormality detection device 72 monitors whether the door 32 has been opened or closed (step S11). The abnormality detection device 72 receives notification from the drive unit control unit 71 that the door 32 has been opened or closed.

[0035] If the door 32 is opened or closed (Step S11: Yes), the time measurement unit 721 of the abnormality detection device 72 measures the door open time and door closed time of the door 32 (Step S12).

[0036] Then, the abnormality detection unit 723 compares the door opening time and door closing time measured by the time measurement unit 721 with the reference time stored in the storage unit 722 (door opening time and door closing time when both door motors are functioning normally) each time the door 32 is opened and closed (step S13). For example, if door motor DM1 malfunctions, the driving force for opening and closing the door 32 decreases. Therefore, the door opening time and door closing time of the door 32 become slower compared to when both door motors DM1 and DM2 are functioning properly. If the difference between the door opening time and door closing time measured by the time measurement unit 721 each time the door 32 is opened and closed and the reference time is greater than or equal to a predetermined value (step S14: Yes), the abnormality detection unit 723 determines that there is an abnormality in the door motor 41.

[0037] The abnormality detection unit 723 outputs to the drive unit control unit 71 and the input / output device 100 that an abnormality has occurred in the door motor 41 (step S15). Upon receiving notification that an abnormality has occurred in the door motor 41, the drive unit control unit 71 drives the doors 32 of the elevator car 31 to open and close in safety mode (step S16). Safety mode is an operation (opening / closing control) in which the opening and closing acceleration and opening and closing speed of the doors 32 of the elevator car 31 are reduced compared to normal operation. In addition, in safety mode operation, the door open holding current and door closed holding current are suppressed to hold the doors 32 open or closed. Furthermore, in safety mode operation, the elevator car 31 may be stopped at the nearest floor to allow passengers to disembark, and an announcement such as "Operation will be suspended for a while" may be made.

[0038] As described above, the door motor abnormality detection device 72 according to the embodiment can detect that any of the multiple door motors 41 have malfunctioned by comparing the door opening time and door closing time measured by the time measurement unit 721 each time the door 32 is opened and closed with the reference time (door opening time and door closing time under normal conditions) stored in the storage unit 722.

[0039] Specifically, even if a single ammeter is provided on the converter 93 side and the current supplied to each of the multiple door motors is not measured, the door motor abnormality detection device 72 according to this embodiment can detect that an abnormality has occurred in any of the multiple door motors by changing the software alone, without requiring any hardware changes such as adding a new ammeter. Therefore, the door motor abnormality detection device 72 according to this embodiment can improve the abnormality detection accuracy of elevator systems using multiple door motors without adding any new parts.

[0040] If both door motor DM1 and door motor DM2 fail, the likelihood of an accident in which passengers are trapped inside the elevator car 31 increases. The door motor abnormality detection device 72 according to the embodiment operates in safety mode if, for example, door motor DM1 is disconnected but door motor DM2 is functioning normally. Safety mode is operation (opening and closing control) in which the opening and closing acceleration and opening and closing speed of the door 32 are reduced compared to normal operation. In addition, in safety mode operation, the door open holding current and door closed holding current are suppressed to maintain the open and closed position of the door 32. By operating in safety mode, the current value flowing to the healthy door motor DM2 can be suppressed, thereby reducing the load on the healthy door motor DM2. This reduces the probability that the healthy door motor DM2 will fail before the disconnected door motor DM1 is repaired, and thus reduces the probability of an accident in which passengers are trapped inside the elevator car 31.

[0041] Although embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, the above description described a case in which two door motors are connected in parallel, but the number of door motors connected in parallel may be three or four.

[0042] Furthermore, although the above description described the case where two position sensors are provided for one side of the door 32, additional position sensors may be provided at intermediate positions between the fully open and closed states of the door 32.

[0043] (Variation 1) The first embodiment describes a case in which the door opening time and door closing time of the door 32 are measured using position sensors 38 (position sensors 381 and 383) and a timer. One method for measuring the door opening time and door closing time of the door 32 is to use a cam switch. A cam switch is a switch whose output state changes according to the position of the door 32. A cam switch is, for example, a switch in which the contact part is turned on and off by a cam mechanism. For example, a disc with a recess is rotated in accordance with the movement of the door 32, and when the position of the recess on the disc reaches a predetermined position, the contact turns on. Two discs with recesses are used, and the positions of the recesses are set so that when the position sensors 381 and 383 reach the position where they detect the door 32, their respective contacts turn on. The timer of the time measurement unit 721 measures the time from when the drive unit control unit 71 issues a door closing command to the door motor 41 via the drive unit 90 when the door 32 is in the open state until it receives a signal from the cam switch indicating that it has turned on. Furthermore, the timer in the time measurement unit 721 measures the time from when the drive unit control unit 71 issues a door open command to the door motor 41 via the drive unit 90 while the door 32 is in the closed position, until it receives a signal from the cam switch indicating that it has turned on.

[0044] (Modification 2) The above explanation describes a case where the door motor 41 is judged to be functioning correctly each time the door 32 is opened or closed. As a variation, the door motor 41 can also be judged to be functioning correctly during the initial door opening. Initial door opening (initial door closing) refers to the door opening (door closing) operation when power is restored after a power outage. During the first door opening after power is restored, the door 32 opens and closes at a lower speed than during normal door opening.

[0045] When opening and closing the door 32 in initial door-open mode, there tends to be a significant difference between the door-open and door-close times when one door motor is faulty and when both door motors are functioning correctly. When determining the health of the door motor 41 in initial door-open (initial door-close) mode, this should be done, for example, late at night.

[0046] (Embodiment 2) Embodiment 1 describes a technique for detecting abnormalities in the door motor 41 based on the opening and closing time of the door 32. Embodiment 2 describes a technique for detecting abnormalities in the door motor 41 based on the door open holding current when the door 32 is held open, and the door closed holding current when the door 32 is held closed.

[0047] Figure 6 is a block diagram of the control unit according to Embodiment 2. In Embodiment 2, the time measurement unit 721 shown in Figure 4 is not used. The ammeter 95 shown in Figure 6 constantly measures the current supplied to the door motor 41. Therefore, the ammeter 95 also measures the door open holding current when the door 32 is held open, and the door closed holding current when the door 32 is held closed.

[0048] The memory unit 722 stores the door open holding current and door closed holding current that the two door motors generate under normal conditions as reference currents. The abnormality detection unit 723 compares the measured door open holding current and door closed holding current measured by the ammeter 95 each time the door 32 is opened and closed with the reference current (reference door open holding current and door closed holding current) stored in the memory unit 722. The abnormality detection unit 723 determines that there is an abnormality in the door motor 41 if the difference between the measured current measured each time the door 32 is opened and closed and the reference current is greater than or equal to a predetermined value.

[0049] Next, the abnormality detection process of the elevator device 10 according to Embodiment 2 will be described with reference to the flowchart shown in Figure 7. The following control is performed based on a program stored in the auxiliary storage unit, and the main control unit is the control unit 80 (CPU). The door open holding current and door closed holding current during normal operation are stored in the storage unit 722 as reference currents.

[0050] The abnormality detection device 72 monitors whether or not the door 32 has been opened or closed (step S31). The drive unit control unit 71 notifies the device of whether or not the door 32 has been opened or closed.

[0051] If the door 32 is opened or closed (step S31: Yes), the abnormality detection device 72 measures the door open holding current and the door closed holding current (step S32).

[0052] Then, the abnormality detection unit 723 compares the door open holding current and door closed holding current measured each time the door 32 is opened and closed with the reference current stored in the memory unit 722 (the door open holding current and door closed holding current when the two door motors are functioning normally) (step S33). If the difference between the measured door open holding current and door closed holding current and the reference current is greater than or equal to a predetermined value (step S34: Yes), the abnormality detection unit 723 determines that there is an abnormality in the door motor 41.

[0053] Figure 8 shows the change in output current of the converter 93 in conjunction with the opening and closing of door 32. The period from time t0 to time t1 and from time t8 onwards is the door closing period. The period from time t4 to time t5 is the door opening period. From time t1 to time t2, the door opening speed of door 32 accelerates, and from time t2 to time t3, it opens at a constant speed. Then, from time t3 to time t4, the door opening speed of door 32 decelerates, and at time t4, door 32 is fully open. When the door closing operation begins at time t5, the door closing speed of door 32 accelerates from time t5 to time t6, and from time t6 to time t7, it closes at a constant speed. Then, from time t7 to time t8, the door closing speed of door 32 decelerates, and at time t8, door 32 is fully closed.

[0054] As shown in Figure 8, even when the door 32 is fully open from time t4 to time t5, a door open holding current flows through the door motor 41 to maintain the open state of the door 32. Similarly, even when the door 32 is fully closed from time t0 to time t1 and from time t8 onward, a door closed holding current flows through the door motor 41 to maintain the closed state of the door 32.

[0055] The solid line in Figure 8 shows the change in output current of the converter 93 associated with the opening and closing of the door 32 when both door motors are functioning normally. The dashed line in Figure 8 shows the change in output current of the converter 93 associated with the opening and closing of the door 32 when one of the two door motors in the door motor 41 is damaged. For example, if one of the door motors DM1 is damaged, the measurement value of the ammeter 95 that measures the current supplied by the converter 93 to the door motor 41 will be smaller than when both door motors are functioning properly. Since there is no current supplied to the door motor DM1, the holding current will also be smaller.

[0056] If the abnormality detection unit 723 determines that there is an abnormality in the door motor 41, it outputs to the drive unit control unit 71 and the input / output device 100 that an abnormality has occurred in the door motor 41 (step S35). Upon receiving notification that an abnormality has occurred in the door motor 41, the drive unit control unit 71 drives the doors 32 of the elevator car 31 to open and close in safety mode (step S36). Safety mode is an operation (opening and closing control) in which the opening and closing acceleration and opening and closing speed of the doors 32 of the elevator car 31 are reduced compared to normal operation. In safety mode operation, the elevator car 31 may be stopped at the nearest floor to allow passengers to disembark, and an announcement such as "Operation will be suspended for a while" may be made.

[0057] As shown in Figure 8, the current changes significantly over a short period of a few seconds during the door-open period from time t1 to time t4 and the door-closed period from time t5 to time t8. Measuring a current that changes rapidly over such a short period of time will result in a large measurement error. Therefore, judging whether or not the system is functioning normally based on the value of this rapidly changing current over such a short period of time increases the probability of making a false judgment. For this reason, the abnormality detection unit 723 determines whether or not there is an abnormality in the door motor 41 based on the holding current, which does not change over a long period of time.

[0058] As described above, the door motor abnormality detection device 72 according to the embodiment can detect that one of the multiple door motors 41 has malfunctioned by comparing the door open holding current and door closed holding current measured each time the door 32 is opened and closed with the door open holding current and door closed holding current under normal conditions. Specifically, even if one ammeter is provided on the converter 93 side and the current supplied to each of the multiple door motors is not measured, the door motor abnormality detection device 72 according to the embodiment can detect that an abnormality has occurred in one of the multiple door motors by changing the software alone, without requiring any hardware changes such as installing a new ammeter. As a result, the door motor abnormality detection device 72 according to the embodiment can improve the accuracy of abnormality detection in elevator systems using multiple door motors without adding a new ammeter. The door motor abnormality detection device 72 according to the embodiment determines the presence or absence of an abnormality by focusing on the holding current, so it can suppress false judgments.

[0059] (Embodiment 3) In Embodiment 1, the health of the door motor 41 was determined by comparing it with the normal door opening time and door closing time. In Embodiment 2, the health of the door motor 41 was determined by comparing the normal door open holding current and door closed holding current. In Embodiment 3, the health of the door motor 41 was determined by an AND condition of two conditions: the door opening / closing time and the holding current of the door 32.

[0060] For example, if a foreign object gets caught in the rail that guides the door 32, the holding current may not change from the normal state, but the opening and closing time of the door 32 may become slower. On the other hand, the DC resistance of the door motor 41 may increase due to deterioration of the brushes or other parts of the door motor 41. In this case, the holding current will be smaller than the normal state, but the opening and closing time of the door 32 may not change from the normal state. The door motor abnormality detection device 72 according to Embodiment 3 can improve the accuracy of abnormality detection in elevator systems using multiple door motors by determining the health of the door motor 41 based on an AND condition of two conditions: the opening and closing time of the door 32 and the holding current.

[0061] (Embodiment 4) In the explanation using Figure 5 of Embodiment 1, the case in which an abnormality in the door motor 41 is detected in step S14, the abnormality is reported (step S15), and the system is operated in safety mode (step S16). In this safety mode, the opening and closing acceleration and speed of the doors 32 of the elevator car 31 are reduced compared to normal operation. In addition, the door open holding current and door closed holding current are suppressed in safety mode. Furthermore, in safety mode, the elevator car 31 is stopped at the nearest floor to allow passengers to disembark. Embodiment 4 describes a case in which the processing content is changed depending on the degree of difference between the opening and closing time of the doors 32 and the opening and closing time in normal operation.

[0062] In the comparison process with the reference time in step S13 of Figure 5, the abnormality detection unit 723 calculates the ratio of the door opening time and door closing time measured by the time measurement unit 721 for each opening and closing of the door 32 to the reference time (door opening time and door closing time under normal conditions) stored in the storage unit 722.

[0063] For example, if the ratio is 10% or less, the abnormality detection unit 723 will only report that an abnormality has occurred and will not issue an instruction to operate in safety mode. If the ratio is between 10% and 20%, the abnormality detection unit 723 will instruct the drive unit control unit 71 to reduce the opening and closing acceleration and speed of the door 32. The abnormality detection unit 723 will also instruct the drive unit control unit 71 to suppress the door open holding current and the door closed holding current. However, it will not issue an instruction to stop the elevator car at the nearest floor. If the ratio is 20% or more, the abnormality detection unit 723 will instruct the drive unit control unit 71 to reduce the opening and closing acceleration and speed of the door 32 and stop the elevator car 31 at the nearest floor.

[0064] (Embodiment 5) In the explanation using Figure 6 of Embodiment 2, the case in which an abnormality in the door motor 41 is detected in step S34, the abnormality is reported (step S35), and the system operates in safety mode (step S36). In this safety mode, the opening and closing acceleration and speed of the doors 32 of the elevator car 31 are reduced compared to normal operation. In addition, the door open holding current and door closed holding current are suppressed in safety mode. Furthermore, in safety mode, the elevator car 31 is stopped at the nearest floor to allow passengers to disembark. Embodiment 5 describes a case in which the processing content is changed depending on the degree of difference between the holding current of the door 32 and the holding current in normal operation.

[0065] In the comparison process with the reference current in step S33 of Figure 6, the abnormality detection unit 723 calculates the ratio of the holding current measured each time the door 32 is opened and closed to the reference current (holding current under normal conditions) stored in the storage unit 722.

[0066] For example, if the ratio is 10% or less, the abnormality detection unit 723 will only report that an abnormality has occurred and will not issue an instruction to operate in safety mode. If the ratio is between 10% and 20%, the abnormality detection unit 723 will instruct the drive unit control unit 71 to reduce the opening and closing acceleration and speed of the door 32. The abnormality detection unit 723 will also instruct the drive unit control unit 71 to suppress the door open holding current and the door closed holding current. However, it will not issue an instruction to stop the elevator car at the nearest floor. If the ratio is 20% or more, the abnormality detection unit 723 will instruct the drive unit control unit 71 to reduce the opening and closing acceleration and speed of the door 32 and stop the elevator car 31 at the nearest floor.

[0067] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0068] 10…Elevator equipment 11…Housing 21-24... Guide rails 31... bus car 31a...Opening 32... Door 35... Counterweight 36…Control Panel 38 (381, 383)... Position sensor 40…Lifting motor 41... Door motor 42...Pulley 43... Wire 70... Control panel 71…Drive Unit Control Unit 72... Anomaly detection device 721...Time measurement unit 722...Storage section 723... Anomaly detection unit 80... Control Unit 801... Control unit for lifting motor 802... Control unit for door motor 90…Drive unit 91... Converter 92... Smoothing Capacitor 93... Converter 95...Ammeter 100… Input / Output Devices DM1, DM2... Door motor

Claims

1. In an elevator system that uses multiple motors to open and close the elevator car doors, a door motor abnormality detection device is provided. A position sensor that detects whether the door is open or closed, A time measuring unit for measuring the door opening time or door closing time, The aforementioned door motor includes a storage unit that stores the door opening time or door closing time as a reference time, An abnormality detection unit determines whether or not there is an abnormality in the door motor by comparing the door opening time or door closing time measured by the time measurement unit each time the door is opened or closed with the reference time, A door motor abnormality detection device having the following features.

2. In an elevator system that uses multiple motors to open and close the elevator car doors, a door motor abnormality detection device is provided. A cam switch whose output state changes according to the position of the aforementioned door, A time measuring unit that measures the time from the output state of the cam switch when the door is in one position to the output state of the cam switch when the door is in another position, A storage unit that stores as a reference time the time when the door motor is operating normally, from the output state of the cam switch when the door is in one position to the output state of the cam switch when the door is in another position, An abnormality detection unit determines that there is an abnormality in the door motor if the difference between the measured time and the reference time is greater than or equal to a predetermined value, by comparing the measured time measured by the time measurement unit each time the door is opened and closed. A door motor abnormality detection device having the following features.

3. In an elevator system that uses multiple motors to open and close the elevator car doors, a door motor abnormality detection device is provided. An ammeter for measuring the door-open holding current when the door is held open, or the door-closed holding current when the door is held closed, A storage unit that stores the door open holding current or door closed holding current when the door motor is functioning normally as a reference current, An abnormality detection unit determines that there is an abnormality in the door motor by comparing the measured current of the door open holding current or door closed holding current measured by the ammeter each time the door is opened and closed with the reference current, and if the difference between the measured current and the reference current is greater than or equal to a predetermined value, A door motor abnormality detection device having the following features.

4. In an elevator system that uses multiple motors to open and close the elevator car doors, a door motor abnormality detection device is provided. A position sensor that detects the open and closed states of the aforementioned door, A time measuring unit for measuring the door opening time and door closing time, An ammeter for measuring the door-open holding current when the door is held open and the door-closed holding current when the door is held closed, A storage unit that stores the door open time and door closed time when the door motor is functioning normally as reference times, and stores the door open holding current and door closed holding current when the door motor is functioning normally as reference currents, An abnormality detection unit determines that there is an abnormality in the door motor when the difference between the door open time or door closed time measured by the time measurement unit each time the door is opened and closed and the reference time is greater than or equal to a predetermined value, and the difference between the measured current of the door open holding current or door closed holding current measured by the ammeter each time the door is opened and closed and the reference current is greater than or equal to a predetermined value. A door motor abnormality detection device having the following features.

5. If the abnormality detection unit determines that there is an abnormality in the door motor, it notifies the control unit that controls the door motor that there is an abnormality. The control unit controls the opening and closing of the door in a mode that limits the current required for opening and closing the door. An abnormality detection device for a door motor according to any one of claims 1 to 4.

Images