Position detection device and position detection method for an elevator

Abstract

The present invention provides an elevator position detection device capable of determining whether a data detection unit that acquires images within a shaft using an image sensor has deteriorated. The elevator position detection device includes a motion detector (9) having a data detection unit (91) that acquires images within the shaft during the car's movement within the shaft, a position calculation unit (92) that calculates the car's position based on the images, an index calculation unit (94) that calculates the performance index (I) of the data detection unit based on the images, and a state determination unit (64) that determines the performance status of the data detection unit based on the car's position and the performance index.

Description

Technical Field

[0001] This invention relates to an elevator position detection device and method for detecting the position of an elevator car based on images within the shaft. Background Technology

[0002] In electronic elevator safety devices, a rotary encoder mounted on the speed governor pulley measures the car's speed and position. The safety device uses the signals output by the rotary encoder as the car moves to measure its position and speed. If the safety device determines that the car's operating state is abnormal based on the measured speed and position, it will bring the car to an emergency stop.

[0003] Techniques that use images from inside the shaft to detect the speed or position of the car instead of such a speed limiter are known (e.g., see Patent Document 1).

[0004] In the technology described in Patent Document 1, a measuring device with an image sensor and an image processing unit is installed in the car. The image sensor converts an image of the surface of the guide rail into an electrical signal. The image processing unit uses image processing corresponding to the electrical signal from the camera unit to calculate the position and speed of the car.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: International Publication No. 2021 / 038984 Summary of the Invention

[0008] The technical problem that the invention aims to solve

[0009] In the aforementioned prior art, when the performance of the image sensor deteriorates due to changes over the years, the accuracy and reliability of the detected position and velocity decrease. Therefore, it is necessary to determine whether the image sensor has deteriorated and to be able to perform maintenance when deterioration is detected.

[0010] Therefore, the present invention provides an elevator position detection device and position detection method, which can determine whether the data detection unit for acquiring images of the shaft using an image sensor has deteriorated.

[0011] Technical solutions for solving technical problems

[0012] To solve the above problems, the elevator position detection device of the present invention includes: a movement detector disposed in the car, which has a data detection unit that acquires images of the car within the shaft during the car's movement range within the shaft; a position calculation unit that calculates the car's position based on the images; an index calculation unit that calculates the performance index of the data detection unit based on the images; and a status judgment unit that judges the performance status of the data detection unit based on the car's position and the performance index.

[0013] To solve the above problems, the elevator position detection method of the present invention is characterized by: calculating the position of the car based on the image in the shaft acquired by the data detection unit of the motion detector installed in the car; calculating the performance index of the data detection unit based on the image; and judging the performance status of the data detection unit based on the calculated position and performance index of the car.

[0014] Invention Effects

[0015] According to the present invention, it is possible to determine whether the performance of the data detection unit has deteriorated.

[0016] Other technical issues, features, and effects not described above will become clear in the following description of the embodiments. Attached Figure Description

[0017] Figure 1 This is a structural diagram showing the overall structure of the elevator according to the implementation method.

[0018] Figure 2 This is a functional block diagram illustrating the structure of the position detection device in the implementation method.

[0019] Figure 3 This indicates that guide rail 5a ( Figure 1 A schematic diagram of an example of an image of the surface of a ).

[0020] Figure 4 This is a diagram illustrating an example of the relationship between the car position (d) and the performance index (I).

[0021] Figure 5 This is a diagram illustrating an example of the relationship between the car position (d) and the performance index (I).

[0022] Figure 6 This is a diagram illustrating an example of the relationship between the car position (d) and the performance index (I).

[0023] Figure 7 This indicates elevator control device 6 ( Figure 1 , 2 The flowchart of the action. Detailed Implementation

[0024] Hereinafter, an elevator according to one embodiment of the present invention will be described using the accompanying drawings. In the drawings, parts with the same reference numerals indicate the same constituent element or constituent elements having similar functions.

[0025] Figure 1 This is a structural diagram illustrating the overall structure of an elevator according to one embodiment of the present invention.

[0026] like Figure 1As shown, in this embodiment, the car 1 and the counterweight 2 are mechanically connected to one end and the other end of the main cable 3, respectively. The main cable 3 is wound around a grooved sheave of the traction machine 4. Thus, the car 1 and the counterweight 2 are suspended within the hoistway of the building. That is, this embodiment is a so-called bucket-type (traction) elevator. Furthermore, in this embodiment, the traction machine 4 is located in a machine room within the hoistway.

[0027] When the motor of the traction machine 4 rotates, driving the pulley to rotate, the main cable 3 is linearly driven by the friction between the pulley and the main cable 3. As a result, the car 1 and the counterweight 2 move in opposite directions up and down within the hoistway. The elevator control device 6 controls the rotation of the motor to control the movement of the car 1.

[0028] Elevator control unit 6 includes a power converter (e.g., an inverter) that supplies power to traction machine 4 and a control unit that controls the power converter (described later). Figure 2 In addition, in this embodiment, the elevator control device 6 is installed together with the traction machine 4 in the machine room.

[0029] The car 1 is movably engaged with guide rails 5a and 5b via a guide device 20 (e.g., guide shoe). Therefore, the car 1 is guided by guide rails 5a and 5b and moves between any floors. Alternatively, in this embodiment, general T-shaped guide rails are used as guide rails 5a and 5b. Furthermore, the counterweight 2 is guided by a guide rail (not shown) for the counterweight.

[0030] A safety control device 8 is installed on the upper part of the car 1. The safety control device 8 is electrically connected to a motion detector 9 installed on the upper part of the car 1. The motion detector 9 has a data detection unit composed of an image sensor. The data detection unit of the motion detector 9 acquires an image of the surface of a stationary object, namely the guide rail 5a, within the hoistway.

[0031] CCD or CMOS sensors are used as image sensors. Furthermore, the data detection unit may include an imaging unit that forms an image on the image sensor. The imaging unit is composed of optical components such as lenses.

[0032] In this embodiment, an image of the surface of the front end of the T-shaped foot is acquired as an image of the surface of the guide rail 5a. The motion detector 9 calculates the position and speed of the car 1 based on the image of the surface of the guide rail 5a acquired by the data detection unit. The motion detector 9 outputs a signal corresponding to the calculated values ​​of the position and speed of the car 1.

[0033] In addition, in this embodiment, the height from the reference position, i.e., the ground of the lowest floor, to the floor surface of the car 1 is taken as the position of the car 1.

[0034] The safety control device 8 detects the position and speed of the car 1 based on signals received from the motion detector 9. Based on the detected position and speed values ​​of the car 1, the safety control device 8 determines whether there is an abnormality in the operating state of the car 1. When the safety control device 8 determines that an abnormality exists, it outputs a command signal to cause the car 1 to stop urgently or to transfer the car 1 to a safe state.

[0035] The safety control device 8 operates independently of the elevator control device 6. Furthermore, the motion detector 9 installed on the car 1 and the safety control device 8 transmit power and control signals to the elevator control device 6 via the tail cable 7.

[0036] As described below, the motion detector 9 has the function of calculating performance indicators, which are indicators representing the image detection performance of the data detection unit of the motion detector 9. The motion detector 9 calculates the performance indicators, as well as the position and speed of the car 1, based on images of the surface of the guide rail 5a successively acquired by the data detection unit as the car 1 moves within the hoistway. The motion detector 9 outputs a signal corresponding to the calculated value of the performance indicators.

[0037] The safety control device 8 detects performance indicators, as well as the position and speed of the car 1, based on signals received from the motion detector 9. The safety control device 8 then transmits the detected performance indicators and the position of the car 1 to the elevator control device 6 via the tail cable 7.

[0038] The elevator control device 6 stores performance indicators and the position of the car 1 received from the safety control device 8. Based on multiple data points of the performance indicators and the position of the car 1 stored during car 1 movement, the elevator control device 6 determines the state of the image detection performance of the data detection unit of the motion detector 9. In this embodiment, the determination result obtained by the elevator control device 6 is displayed on a maintenance terminal 70 that is communicatively connected to the elevator control device 6.

[0039] Figure 2 This is a functional block diagram illustrating the structure of the electronic security system in the implementation method.

[0040] In this embodiment, the motion detector 9, the safety control device 8, and the elevator control device 6 each have a computer system such as a microcomputer, and the computer system works as the functional units described later.

[0041] The motion detector 9 has a data detection unit 91, a position calculation unit 92, a speed calculation unit 93, and an index calculation unit 94.

[0042] The data detection unit 91 uses an image sensor to acquire an image of the surface of the guide rail 5a.

[0043] The position calculation unit 92 calculates the position of the car 1 at predetermined time intervals using image processing (e.g., image correlation method) based on the image of the surface of the guide rail 5a acquired by the data detection unit 91. The position calculation unit 92 outputs a signal corresponding to the calculated position of the car 1.

[0044] The speed calculation unit 93 calculates the speed of the car 1 at predetermined time intervals using image processing (e.g., image correlation method) based on the image of the surface of the guide rail 5a acquired by the data detection unit 91. The speed calculation unit 93 outputs a signal corresponding to the calculated speed of the car 1.

[0045] The performance index calculation unit 94 calculates the performance index of the data detection unit 91 at predetermined time intervals based on the image of the surface of the guide rail 5a acquired by the data detection unit 91. The performance index calculation unit 94 outputs a signal corresponding to the calculated value of the performance index.

[0046] In this embodiment, the statistical measures (mean, median, maximum, discrete value, etc.) of the brightness distribution in the image of the surface of the guide rail 5a are used as performance indicators.

[0047] The safety control device 8 includes a car position (d) detection unit 81, a car speed (v) detection unit 82, an index (I) detection unit 83, an abnormality detection unit 84, and a power cut-off unit 85.

[0048] The car position (d) detection unit 81 detects the position (d) of the car 1 in the hoistway based on the signal from the position calculation unit 92 (hereinafter referred to as "car position (d)"). The car position (d) detection unit 81 sends the detected value of the car position (d) (= the calculated value obtained by the position calculation unit 92) to the anomaly detection unit 84 and the elevator control device 6.

[0049] The car speed (v) detection unit 82 detects the speed (v) of the car 1 (hereinafter referred to as "car speed (v)") based on the signal from the speed calculation unit 93. The car speed (v) detection unit 82 sends the detected value of the car speed (v) (= the calculated value obtained by the speed calculation unit 93) to the anomaly detection unit 84.

[0050] The index (I) detection unit 83 detects the performance index (I) of the data detection unit 91 based on the signal from the index calculation unit 94. The index (I) detection unit 83 sends the detected value of the performance index (I) (= the calculated value obtained by the index calculation unit 94) to the elevator control device 6.

[0051] The anomaly detection unit 84 determines whether there is an anomaly in the operating state of the car 1 based on the car position (d) sent from the car position (d) detection unit 81 and the car speed (v) sent from the car speed (v) detection unit 82.

[0052] When the anomaly detection unit 84 determines that the operating state of the car 1 is abnormal, for example, when it determines that the lifting speed of the car 1 is above the specified overspeed, the power cut-off unit 85 sends a power cut-off command S. C * .

[0053] Electromagnetic switching device 100 receives power cut-off command S C * At this time, the normally open contact, which is in a closed state, opens, cutting off the power supply from power supply 400 to elevator control device 6. Therefore, the power supply to traction machine 4 is stopped. Furthermore, with the power supply cut off, the brake device (not shown) enters the braking state. Thus, elevator 1 comes to an emergency stop.

[0054] The elevator control device 6 includes a power converter 61, a control unit 62, a storage unit 63, and a status judgment unit 64.

[0055] The power converter 61 has an inverter circuit that supplies AC power to the AC motor driving the traction machine 4.

[0056] The control unit 62 controls the power converter 61 to control the AC motor that drives the traction machine 4. This controls the operation of the car 1.

[0057] The storage unit 63 sequentially stores the car position (d) sent from the car position (d) detection unit 81 and the performance index (I) sent from the index (I) detection unit 91. For example, a semiconductor memory is used as the storage unit 63.

[0058] In addition, the set of data (d, I) of the car position (d) and performance index (I) stored in the storage unit 63 are the detection values ​​(= calculated values) at the same time point.

[0059] In this embodiment, during the maintenance and inspection of the motion detector 9, the car 1 is operated for maintenance, and the detected values ​​of the car position (d) and performance index (I) are stored in the storage unit 63.

[0060] The status judgment unit 64 judges the status of the image detection performance of the data detection unit 91 based on multiple sets of data of car position (d) and performance index (I) stored in the storage unit 63, and sends the judgment result to the maintenance terminal 70.

[0061] The maintenance terminal 70 displays the judgment result sent from the status judgment unit 64 on the display device (e.g., liquid crystal display) provided by the maintenance terminal 70.

[0062] In addition, in this embodiment, the position detection device consists of a data detection unit 91, a position calculation unit 92, an index calculation unit 94, a car position (d) detection unit 81, an index (I) detection unit 83, a storage unit 63, and a status judgment unit 64.

[0063] Figure 3 This indicates that guide rail 5a ( Figure 1 A schematic diagram of an example of an image of the surface of a ).

[0064] exist Figure 3 The data detection unit 91 using the motion detector 9 is shown in the figure. Figure 2 The image Img(t) acquired at time t and at time t+Δt (Δt: image Img(t+Δt) acquired at the period (e.g., frame period) are both images of the exposed surface of the steel constituting guide rail 5a, representing a pattern of brightness distribution showing the uneven distribution of the exposed surface of the steel. Additionally, between time t and time t+Δt, the car 1 ( Figure 1 )decline.

[0065] Because car 1 has moved, therefore... Figure 3 As shown, an image offset Δd is generated between the image Img(t) and the image Img(t+Δt). Additionally, Figure 3 During the descent of the car 1, an image offset Δd is generated in the upward direction within the image frame. This image offset Δd is calculated in this embodiment by comparing the image Img(t) with the image Img(t+Δt) using an image correlation method. In this case, the image Img(t) or a portion thereof is moved successively by a predetermined amount along the long side of the guide rail 5a within the image frame, and the correlation function value between the moved image Img(t) and the image Img(t+Δt) is calculated. The total amount of movement of the image Img(t) when the correlation function value reaches its maximum value is taken as the image offset Δd.

[0066] The offset Δd of the image is equivalent to the amount of movement of car 1 in time Δt. Figure 3 (The value in the image is the descent amount). Additionally, the direction of image offset within the image frame indicates the direction of movement of car 1 (ascending or descending). Therefore, if the sign of the image offset is set accordingly to the offset direction of the image, for example, setting the downward direction (ascending direction) as positive and the upward direction (descending direction) as negative, then for each Δt, the image offset Δd is calculated and accumulated to the car position at startup, allowing the calculation of the current car position d.

[0067] Furthermore, for the guide rail 5a, to give its surface an uneven surface, it is preferable to perform surface processing such as grinding. Additionally, it is preferable that the motion detector 9 has a light source that illuminates the surfaces of the guide rail 5a respectively. This improves the accuracy of the car position d calculation.

[0068] Figure 4 This indicates that the storage unit 63 ( Figure 2 A diagram illustrating an example of the relationship between the car position (d) and performance index (I) stored in the database.

[0069] Figure 4 In the case of state determination unit 64 ( Figure 2 The data detection unit 91 and the object being detected, i.e., guide rail 5a, are judged to be normal.

[0070] In addition, in this embodiment, the maintenance terminal 70 ( Figure 2 The maintenance terminal 70 acquires data (d, I) and the status judgment result from the status judgment unit 64, and generates a graph representing the relationship between d and I. The maintenance terminal 70 displays the generated graph and status judgment result on a display device (e.g., a liquid crystal display) provided with the maintenance terminal 70. This allows maintenance technicians to quickly check the status of the data detection unit 91 and the guide rail 5a.

[0071] like Figure 4 As shown, within the travel range of car 1 (bottom floor to top floor), performance index I exceeds the threshold I. th (I>I) th Therefore, it was determined that the data detection unit 91 and the guide rail 5a were normal.

[0072] In this embodiment, the brightness distribution of the image information acquired by the data detection unit 91, i.e., the image information of the guide rail 5a surface used for detecting position and speed (refer to the above) is represented. Figure 3 The statistical measure of the car position is used as the performance index I. Statistical measures include mean, maximum, and variance. The smaller I is, the lower the accuracy or reliability of the car position calculated by the position calculation unit 92 and the car speed calculated by the speed calculation unit 93.

[0073] In addition, in this embodiment, the average value is used as a statistical measure.

[0074] Threshold I th This refers to the value of performance metric I when the desired accuracy or reliability can no longer be achieved. Therefore, as... Figure 4 As shown, within the moving range of car 1, if I>I th If so, it is determined that the data detection unit 91 and the guide rail 5a are normal.

[0075] I is preset in the state determination unit 64 th Additionally, for example, by accelerating the reliability testing of position detection actions, I can be set... thAlternatively, I can be set by conducting a simulated position detection operation test that simulates the output signal of the data detection unit 91 when acquiring image information, by inputting the car position (d) detection unit 81, the car speed (v) detection unit 82, and the index (I) detection unit 83. th .

[0076] Figure 5 This indicates that the storage unit 63 ( Figure 2 A diagram illustrating an example of the relationship between the car position (d) and performance index (I) stored in the database.

[0077] like Figure 5 As shown, because in the range of motion of car 1, I≤I th Therefore, the state judgment part 64 ( Figure 2 It was determined that the performance (image detection performance) of the data detection unit 91 had deteriorated.

[0078] Figure 6 This indicates that the storage unit 63 ( Figure 2 A diagram illustrating an example of the relationship between the car position (d) and performance index (I) stored in the database.

[0079] Figure 6 In the case of state determination unit 64 ( Figure 2 The surface of the object being tested, namely guide rail 5a, is contaminated.

[0080] like Figure 6 As shown, within the moving range of car 1, locally in Figure 4 In the range D of the car position d, I≤I th At car position d outside range D, I>I th Therefore, the status judgment unit 64 determines that although the performance of the data detection unit 91 has not deteriorated, the surface of the detected object, namely the guide rail 5a, corresponding to the range D of the car position d is contaminated.

[0081] Figure 7 This refers to the elevator control device 6 in the implementation method. Figure 2 The flowchart shows the operation of the data detection unit 91 (processing to determine the state of image detection performance).

[0082] In step S1, the elevator control device 6 uses the storage unit 63 to store the car position d detected by the car position (d) detection unit 81 and the index (I) detection unit 83 in the safety control device 8 within the movement range of the car 1, as well as the data ((d, I)) of the performance index I corresponding to d.

[0083] In this embodiment, during the maintenance and inspection of the motion detector 9, the car 1 is moved from the bottom floor to the top floor or from the top floor to the bottom floor at a speed lower than the rated speed, while data ((d,I)) is stored in the storage unit 63.

[0084] After the elevator control device 6 executes step S1, it then executes step S2.

[0085] In step S2, the elevator control device 6 uses the status determination unit 64 to determine whether a status determination start command has been received from the maintenance terminal 70. If the elevator control device 6 determines that a status determination start command has been received ("Yes" in step S2), it then executes step S3. If the elevator control device 6 determines that a status determination start command has not been received ("No" in step S2), it executes step S2 again.

[0086] In step S3, the elevator control device 6 uses the status judgment unit 64 to determine whether any of the multiple data (d, I) stored in the storage unit 63 contains a performance index I that is within a specified threshold I. th The following is d. The elevator control device 6 determines that performance index I is below the specified threshold I. th If step d is true ("Yes" in step S3), then proceed to step S4. The elevator control device 6 determines that performance index I does not exist within the specified threshold I. th If the following condition is met (No in step S3), then proceed to step S5.

[0087] In step S4, the elevator control device 6 uses the status judgment unit 64 to determine whether any of the multiple data (d, I) stored in the storage unit 63 contains a performance index I that is greater than a predetermined threshold I. th The elevator control device 6 determines that performance index I is greater than the specified threshold I. th When step d is reached ("Yes" in step S4), step S6 is then executed. The elevator control device 6 determines that no performance index I is greater than the specified threshold I. th If d is "No" in step S4, then proceed to step S7.

[0088] In step S5, the elevator control device 6 uses the status judgment unit 64 to determine that the data detection unit 91 is normal. After executing step S5, the elevator control device 6 then executes step S8.

[0089] In step S6, the elevator control device 6 uses the status judgment unit 64 to determine that the surface of the detected object, namely the guide rail 5a, is contaminated. After executing step S6, the elevator control device 6 then executes step S8.

[0090] In step S7, the elevator control device 6 uses the status judgment unit 64 to determine that the data detection unit 91, i.e., the image sensor, has deteriorated. After executing step S5, the elevator control device 6 then executes step S8.

[0091] In step S8, the elevator control device 6 uses the status judgment unit 64 to send the judgment result (steps S5, S6, S7) and multiple data (d, I) stored in the storage unit 63 to the maintenance terminal 70.

[0092] According to this embodiment, the performance index of the data detection unit 91 is calculated based on image information acquired by the data detection unit 91 of the movement detector 9 installed on the car 1 within the moving range of the car 1. The detection state of the data detection unit 91 is determined based on the calculated value of the performance index and the car position detection value corresponding to the calculated value. Therefore, the state (normal, deteriorated) of the data detection unit 91 can be determined with high reliability. Furthermore, it is also possible to determine that the guide rail 5a is contaminated.

[0093] Furthermore, by determining the detection status of the data detection unit 91 based on the calculated value of the performance index and the corresponding car position detection value, the replacement period of the data detection unit 91 or the motion detector 9 including the data detection unit 91 can be determined. Therefore, the reliability of car position and speed detection can be ensured without periodic replacement, and the replacement frequency of the data detection unit 91 or the motion detector 9 can be reduced.

[0094] Furthermore, the present invention is not limited to the embodiments described above, and includes various modifications. For example, the embodiments described above are provided in detail for ease of understanding of the present invention, and are not limited to having all the structures described. In addition, for a part of the structure of the embodiments, other structures can be added, deleted, or replaced.

[0095] For example, an elevator can also be a so-called machine room-less elevator, where the traction machine and elevator control device are located inside the shaft.

[0096] In addition, an image sensor can be either a surface sensor or a line sensor.

[0097] Alternatively, the object being tested can be a long object such as a strip or a component instead of a guide rail.

[0098] Furthermore, according to the above embodiment, when the data detection unit has an imaging unit, the degradation of the image detection performance of the data detection unit caused by the degradation of the imaging performance of the imaging unit can also be determined in the same way.

[0099] Explanation of reference numerals in the attached figures

[0100] 1…Car, 2…Counterweight, 3…Main rope, 4…Traction machine, 5a, 5b…Guide rails, 6…Elevator control device, 7…Tail cable, 8…Safety control device, 9…Motion detector, 20…Guide device, 61…Power converter, 62…Control unit, 63…Storage unit, 64…Status judgment unit, 70…Maintenance terminal, 81…Car position (d) detection unit, 82…Car speed (v) detection unit, 83…Indicator (I) detection unit, 84…Abnormal detection unit, 85…Power cut-off unit, 91…Data detection unit, 92…Position calculation unit, 93…Speed ​​calculation unit, 94…Indicator calculation unit, 100…Electromagnetic opening and closing device, 400…Power supply.

Claims

1. A position detection device for an elevator, characterized in that, include: A motion detector installed in the car has a data detection unit that acquires images of the shaft within the range of movement of the car within the shaft. A position calculation unit that calculates the position of the car based on the image; An index calculation unit that calculates the performance index of the data detection unit based on the image; and The status determination unit determines the performance status of the data detection unit based on the position of the car and the performance indicators.

2. The elevator position detection device as described in claim 1, characterized in that: The performance metric is a statistical measure of the brightness distribution in the image.

3. The elevator position detection device as described in claim 2, characterized in that: The statistic is any one of the mean, median, maximum, or discrete value.

4. The elevator position detection device as described in claim 1, characterized in that: The image is a surface image of the object being inspected, which is placed inside the well.

5. The elevator position detection device as described in claim 4, characterized in that: The object being tested is a guide rail.

6. The elevator position detection device as described in claim 1, characterized in that: The status determination unit determines the performance status of the data detection unit by comparing the performance indicators with a predetermined threshold.

7. The elevator position detection device as described in claim 4, characterized in that: The state determination unit determines the performance status of the data detection unit and the surface status of the object being detected by comparing the performance indicators with a predetermined threshold.

8. A method for detecting the position of an elevator, comprising calculating the position of the elevator car based on an image of the shaft acquired by a data detection unit of a motion detector installed in the car, characterized in that: The performance index of the data detection unit is calculated based on the image. The performance status of the data detection unit is determined based on the calculated position of the car and the performance indicators.

Images