CN114111566B

CN114111566B - Measuring device, measuring system and moving body operation method

Info

Publication number: CN114111566B
Application number: CN202110538156.5A
Authority: CN
Inventors: 大西义人; 岩本晃; 齐藤勇来; 近藤健史; 大沼直人
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 2020-08-28
Filing date: 2021-05-18
Publication date: 2024-12-10
Anticipated expiration: 2041-05-18
Also published as: CN114111566A; JP2022039414A; JP7453883B2

Abstract

The measuring device, measuring system and moving body operation method of the present invention measure the absolute position of a moving object on a moving path at high speed and high precision. The measuring system includes: a light transmitting unit that responds to a selection signal to transmit light to illuminate a stationary structure in the moving path; an imaging unit that images scattered light from the stationary structure on a photographing surface; a photographing unit that obtains the light signal imaged on the photographing surface and converts it into an electrical signal; an image processing unit that calculates information related to the absolute position of the moving body (car) based on a photographed image generated from the electrical signal converted by the photographing unit, the image processing unit performs a mark recognition process that determines a reference line representing the absolute position of the mark using light and dark brightness changes in a second direction perpendicular to the first direction in the photographed image when the image of the mark is included in the photographed image, and a movement amount calculation process that calculates the movement amount of the moving body from the reference line determined by the mark recognition process.

Description

Measuring device, measuring system, and moving body operation method

Technical Field

The present invention relates to a measuring apparatus, a measuring system, and a moving object operation method, and is preferably applied to a measuring apparatus, a measuring system, and a moving object operation method that calculate information on movement of a moving object such as an elevator car.

Background

Conventionally, in an elevator having a car (hereinafter referred to as an "elevator car" or "car") as a moving body, a governor rope is used as a safety device for monitoring the position of the elevator car, the moving speed of the elevator car, and the like.

In recent years, a sensor (hereinafter referred to as a "position movement speed sensor") that measures the position and movement speed of an elevator car in a noncontact manner instead of a speed limiter rope has been known. For example, patent document 1 discloses an optical type position and movement speed sensor that measures the position and movement speed of an elevator car by capturing an image of a structure existing in a hoistway with an image sensor provided in the elevator car. In the noncontact position and movement speed sensor, since an elongated structure such as a speed limiter rope is not required, there is an effect of improving mountability and maintainability, and there is an effect of preventing measurement errors due to sliding.

Prior art literature

Patent literature

Patent document 1 International publication No. 2019-239536

Disclosure of Invention

Technical problem to be solved by the invention

However, when the elevator car is running, the measuring device for detecting the position and the moving speed of the elevator car needs to detect that the car is safely stopped at the door zone in the hoistway, and control the opening/closing device of the door so as not to operate when the car is outside the door zone. However, the above-described conventional optical position and movement speed sensor relatively measures the movement distance based on the time difference of the image of the structure captured by the image sensor, and can detect the reference position only by being combined with a separate other structure. Therefore, there is a problem in that it is difficult to measure the absolute position of the reference position provided in the hoistway from above the elevator car moving at high speed with high accuracy.

The present invention has been made in view of the above, and an object of the present invention is to provide a measuring device, a measuring system, and a moving object operation method capable of measuring an absolute position of a moving object on a moving path at high speed and with high accuracy.

Technical means for solving the technical problems

In order to solve the above-mentioned problems, the present invention provides a measuring device provided to a moving body moving on a moving path and measuring a position of the moving body, the measuring device including a light transmitting section that transmits light for irradiating a stationary structure disposed in a first direction parallel to a moving direction of the moving body on the moving path in response to a strobe signal generated at a prescribed period, an imaging section that images scattered light from the stationary structure generated by the light onto a photographing surface, a photographing section that acquires an optical signal of the scattered light imaged onto the photographing surface within an exposure time prescribed by the strobe signal and converts it into an electric signal, and an image processing section that generates a photographed image at the prescribed period and performs image processing on the electric signal obtained after conversion by the imaging section and calculates information about an absolute position of the moving body based on the photographed image, the image acquiring section including a mark that recognizes the mark, a brightness of the moving structure is set in the first direction by the first image processing and a brightness processing in which the absolute position of the moving structure is determined by the first position is recognized, and a brightness processing in the second position is set in the determined.

In order to solve the above problems, the present invention provides a measuring system for measuring a position of a moving body moving along a moving path, the measuring system including a measuring device provided on the moving body, and a mark provided on a stationary structure disposed along a first direction parallel to a moving direction of the moving body on the moving path at least one of the marks at predetermined intervals along the first direction. In the measuring system, the measuring device includes a light transmitting section that transmits light that irradiates a stationary structure disposed in a first direction parallel to a moving direction of the moving body on the moving path in response to a strobe signal generated at a prescribed period, an imaging section that images scattered light from the stationary structure generated by the light onto a photographing surface, a photographing section that acquires an optical signal of the scattered light imaged onto the photographing surface within an exposure time prescribed by the strobe signal and converts it into an electric signal, and an image processing section that generates the strobe signal at the prescribed period and performs image processing on the electric signal converted by the imaging section to generate a photographed image, and calculates information on an absolute position of the moving body based on the photographed image, the image processing section including a mark recognition process in which a movement amount of any one of the marks is included in the photographed image, a brightness change in the first direction being calculated from the reference mark in the first direction, and a brightness change in the absolute position in the moving direction being calculated from the reference mark in the first direction being calculated.

In order to solve the above-described problems, the present invention provides a moving object operation method by an elevator system, in which an elevator car is returned to a nearby floor. The elevator system is configured to include a mark provided on a stationary structure disposed in a hoistway in a first direction parallel to a moving direction of the elevator car, at least one of the marks being provided between floors along the first direction, a measuring device provided on the elevator car to capture an image of the stationary structure, and to calculate position information of the mark when the captured image includes the image of the mark, an elevator control unit to control an operation of the elevator car, and floor height information indicating the mark and the position information of the floor for each of the marks. The moving body operation method includes a first step of moving the elevator car to the vicinity of the mark by the elevator control unit, a second step of calculating the position information of the mark from the captured image of the mark at the destination of the movement of the first step by the measuring device, a third step of calculating the movement distance from the mark to the floor by the elevator control unit based on the position information of the mark calculated in the second step and the floor height table, and a fourth step of moving the elevator car by the movement distance calculated in the third step by the elevator control unit.

Effects of the invention

According to the present invention, the absolute position of the moving body on the moving path can be measured at high speed and with high accuracy.

Drawings

Fig. 1 is a diagram showing a configuration example of an elevator system 10 according to embodiment 1 of the present invention.

Fig. 2 is a diagram showing a configuration example of the measurement system 100.

Fig. 3 is a diagram showing an example of the internal configuration of the image processing unit 240.

Fig. 4 is a flowchart showing an example of a processing procedure of the measurement processing of the image processing unit 240.

Fig. 5 is a diagram for explaining a change in a captured image when the car 120 moves.

Fig. 6 is a diagram showing one example of a timing chart of the strobe signal transmitted to the photographing section 230 by the control section 310.

Fig. 7 is a diagram showing an example of the luminance distribution of a captured image in exposure time.

Fig. 8 is a diagram showing a specific example of the luminance mark 150.

Fig. 9 is a diagram showing one example of the luminance distribution of the captured image of the luminance mark 151.

Fig. 10 is a diagram for explaining a dimensional relationship between the luminance mark 150 and the imaging region of the measuring apparatus 110.

Fig. 11 is a conceptual diagram for explaining a procedure of return operation control of the elevator car 120.

Fig. 12 is a diagram showing a measurement device 1200 according to embodiment 2 of the present invention centering on an internal configuration example of an imaging unit 1220.

Fig. 13 is a diagram illustrating a measurement apparatus 1300 according to embodiment 3 of the present invention centering on an example of the internal configuration of an imaging unit 1320.

Fig. 14 is a diagram showing a measurement device 1400 according to embodiment 4 of the present invention centering on an example of the internal structure of an imaging section 1420.

Fig. 15 is a diagram showing a configuration example of a measurement system 1500 according to embodiment 5 of the present invention.

Fig. 16 is a diagram showing a configuration example of a vehicle positioning system 1600 in which the measuring device 110 is applied to a vehicle.

Fig. 17 is a diagram showing a configuration example of a crane positioning system 1700 in which the measuring device 110 is applied to a crane.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the embodiments of the present invention described in detail below, an apparatus, a system, and a method are described that identify a reference position provided on a path (moving path) by using a measurement system configured to include a measurement apparatus provided on the moving body and a luminance mark arranged on the path (moving path) guiding the moving body, and measure an absolute position of the moving body determined by the reference position at high speed and high accuracy. However, the present invention is not limited to the embodiments described below.

The measuring device shown in each embodiment is mounted on the upper part of the moving body, and measures information related to the movement of the moving body (specifically, the absolute position of the moving body, the moving speed of the moving body, the acceleration of the moving body, the vibration of the moving body, and the like). For example, the measuring device irradiates (transmits) light from the light transmitting portion of the moving body to the surface of the stationary structure as the subject in response to the strobe signal generated in the control portion. Then, the measuring device causes light (light that can include regular reflection light and diffuse reflection light, hereinafter referred to as "scattered light") that bounces on the surface of the stationary structure to enter the imaging surface of the imaging unit via the imaging unit, and photoelectrically converts the optical signal into an electrical signal in the imaging unit. Then, the measurement device measures information about the reference position (specifically, the presence or absence of a luminance mark as a reference, the reference position possessed by the luminance mark, an ID for discriminating the reference position assigned to each luminance mark, and the like) in the mark recognition section based on the image generated from the electric signal obtained after the conversion. Further, the measurement device measures information about the movement of the moving body (specifically, a movement distance from a reference position of the moving body, a movement speed of the moving body, vibration of the moving body, and the like) in the image processing section based on the image generated from the converted electric signal. Then, the measuring device calculates information of an absolute position of the moving body on the moving path based on the information on the reference position and the information on the movement of the moving body, and transmits the calculated information to the moving body control section for performing the operation control of the moving body or the control of the safety device. Then, the moving body control unit performs operation control of the moving body and control of the safety device based on the information of the absolute position of the moving body calculated by the measuring device.

In addition, in some embodiments, an elevator car is described as an example of a moving body provided with the measuring device of the present invention, but the moving body to which the present invention can be applied is not limited to an elevator car. The techniques shown in the various embodiments can also be applied to a moving body (e.g., an automatic door, a train, a vehicle, a crane, etc.) that moves along a stationary structure (e.g., a rail, a track, a road, etc.) having a scratch that is manually ground. In addition, in the present specification, "light" means electromagnetic waves, and specifically, microwaves, terahertz waves, infrared rays, ultraviolet rays, X-rays, and the like may be used in addition to visible light. Likewise, the measuring system to which the invention can be applied is not limited to the measuring system assembled into an elevator system, but can be applied to, for example, a positioning system for controlling an automatically operated vehicle, a positioning system for a crane, and the like.

In the following description, when the description is made without distinguishing between the same elements, common portions (portions other than the branch codes) among the reference numerals including the branch numbers may be used, and when the description is made with distinguishing between the same elements, the reference numerals including the branch numbers may be used. For example, in the case where the imaging region is described without being particularly distinguished, it is referred to as "luminance mark 150", whereas in the case where the imaging region is described with being distinguished, it is referred to as "luminance mark 150-1" or "luminance mark 150-2".

(1) Embodiment 1

(1-1) Structure of Elevator System 10

As shown in fig. 1, the elevator system 10 includes a measurement system 100, and the measurement system 100 includes a measurement device 110 mounted on an upper portion of an elevator car 120, the elevator car 120 being lifted and lowered in a hoistway (a moving path of a moving body) of a building (not shown), and a plurality of luminance marks 150 (individually, for example, luminance marks 150-1 and 150-2) provided to show a reference position in the hoistway. As shown in fig. 1, the elevator system 10 includes an elevator car 120, an elevator control unit 130, or a guide rail 140, but at least any of these components may be included in the measurement system 100.

The measuring device 110 outputs signal information (e.g., signal information related to the position, moving speed, acceleration, etc. of the elevator car 120) useful for controlling the operation of the elevator car 120 to the elevator control unit 130. The elevator control unit 130 controls the operation of the elevator car 120, controls safety devices, and the like. The arrangement position of the measuring device 110 is not limited to the upper part of the elevator car 120, and may be arranged at a position other than the upper part, for example, a side surface part, a lower part, or the like.

The guide rail 140 is an example of a stationary structure disposed in the hoistway, and is disposed in the hoistway along the moving direction of the moving body (y-axis direction in fig. 1), contacts guide rollers (not shown) of the elevator car 120, and supports the movement of the moving body (elevator car 120). The luminance marks 150 are arranged at predetermined intervals on the top or side of one surface (for example, the sliding surface contacting the guide roller) of the guide rail 140, on the flange surface fastened to the wall surface by the bolts of the guide rail 140, or on the neck portion at the boundary between the sliding surface and the flange surface.

For example, although the brightness mark 150 is attached in the form of a sticker, it may be achieved by processing the guide rail 140 by mechanical engraving or laser marking that is highly resistant to interference such as stains or rust due to aging. Or an indicator such as an LED embedded in the guide rail 140 in advance, which has a high brightness and can be recognized with a high S/N ratio, may be used for the brightness mark 150.

Fig. 2 is a diagram showing a configuration example of the measurement system 100. As shown in fig. 2, the measuring device 110 includes a light transmitting unit 210, an imaging unit 220, an imaging unit 230, and an image processing unit 240. In fig. 2, the optical path is shown by a dotted line with an arrow, and the path of the electric signal is shown by a solid line with an arrow.

The light transmitting unit 210 includes a light source (not shown), and is configured to irradiate light to the guide rail 140 as the subject and the luminance mark 150 provided in the guide rail 140. A light source that is not coherent in time or space, such as an LED (LIGHT EMITTING Diode) or a halogen lamp, may be used for the light source of the light transmitting unit 210, or a light source that is coherent in time or space, such as a laser light source, may be used for the light source of the light transmitting unit 210.

The imaging unit 220 is an optical system that images scattered light, which is obtained by scattering, from the surface of the guide rail 140 or the luminance mark 150, the outgoing light (outgoing light) that is the light irradiated from the light transmitting unit 210 toward the surface of the guide rail 140 or the luminance mark 150 provided in the guide rail 140, on the imaging surface of the imaging unit 230.

The photographing section 230 converts an optical signal (an optical signal representing a scattering luminance distribution on the surface of the guide rail 140 or the surface of the luminance mark 150) from the imaging section 220, that is, an optical signal imaged on a photographing surface including a plurality of pixels (pixels) into an electrical signal corresponding to the luminance of the pixels, and transmits the converted electrical signal as an image signal representing a dark-field image to the image processing section 240. In the present embodiment, the image signal transmitted from the imaging unit 230 to the image processing unit 240 is not limited to the dark-field image, and may be, for example, a bright-field image. For example, a CCD (Charge Coupled Device: charge coupled device) image sensor, a CMOS (Complementary Metal Oxide Semiconductor: complementary metal oxide semiconductor) image sensor, or the like may be used for the photographing section 230. The imaging unit 230 may be a two-dimensional area sensor or a one-dimensional line sensor having a space resolution function in the lifting direction of the car 120.

In addition, in the measurement system 100, a wavelength selective filter such as a bandpass filter may be provided in the imaging unit 220 in the path of the outgoing light from the light transmitting unit 210 and the scattered light thereof, and external light other than the desired wavelength may be removed. In addition, for the purpose of protecting the measuring device 110, a window material or the like may be provided in the path of the incident light and the scattered light in the measuring system 100 so that dust, dirt, or the like does not enter the measuring device 110.

The image processing unit 240 performs predetermined image processing on the image signal (the electric signal obtained by converting the optical signal imaged on the imaging surface) received from the imaging unit 230, calculates information on the movement of the elevator car 120 (car movement-related information) and information on the reference position (reference position-related information) possessed by the luminance mark 150 based on the imaging image generated by the image processing, and transmits these information to the elevator control unit 130. The image processing unit 240 may be configured by an information processing storage medium such as a CPU (Central Processing Unit, a central processing unit), a GPU (Graphics Processing Unit, a graphics processing unit), or a microcontroller, or may be configured by a logic circuit element such as an FPGA (Field-Programmable gate array).

(1-2) Structure of image processing section 240 and measurement processing of image processing section 240

Next, the internal structure of the image processing section 240 and the processing performed by the image processing section 240 will be described in detail.

Fig. 3 is a diagram showing an example of the internal configuration of the image processing unit 240. As shown in fig. 3, the image processing unit 240 includes a control unit 310, a movement amount calculation unit 320, a luminance mark recognition unit 330, and a communication unit 340.

The control section 310 generates a plurality of strobe signals (strobe signals), transmits one strobe signal of the generated plurality of strobe signals to the light transmitting section 210, and transmits the other strobe signal to the photographing section 230. The strobe signal transmitted to the optical transmission section 210 is used as a timing signal that specifies the driving time of the light source in the optical transmission section 210. The strobe signal sent to the photographing section 230 serves as a timing signal for prescribing the exposure time in the photographing section 230. Then, the control unit 310 performs predetermined image processing on the electric signal from the imaging unit 230, and sends the image after the image processing to the movement amount calculation unit 320 and the luminance mark recognition unit 330. In addition, the image processing of the control section 310 is specifically, for example, processing for spatially decomposing an electric signal (for example, an image signal representing a dark-field image) from the photographing section 230 into an image corresponding to the scattering luminance distribution on the surface of the guide rail 140.

The movement amount calculation unit 320 calculates information (car movement-related information) on the movement of the elevator car 120 based on the result of the image processing received from the control unit 310, and sends the calculated signal information to the communication unit 340. Specifically, the car movement related information includes, for example, information indicating the position, movement speed, and the like of the car 120.

The luminance-mark identifying unit 330 performs image identification processing for identifying the luminance mark 150 on the image processed received from the control unit 310, calculates information (reference-position-related information) on the reference position of the luminance mark 150, and transmits the calculated signal information to the communication unit 340. Specifically, the reference position related information includes, for example, information indicating the presence or absence of the luminance mark 150 as a reference, an ID (which will be described in detail later as an "ID pattern") for identifying a reference position (reference position assigned to each luminance mark 150) possessed by the luminance mark 150, and the like.

The communication unit 340 converts the car movement related information received from the movement amount calculation unit 320 and the reference position related information received from the brightness mark recognition unit 330 according to a communication protocol (e.g., a protocol such as CAN (controller area network) communication) receivable by the elevator control unit 130, and outputs the converted signal information to the elevator control unit 130.

Fig. 4 is a flowchart showing an example of processing steps of the measurement processing of the image processing section 240.

According to fig. 4, the image processing section 240 starts measurement based on the strobe signal generated by the control section 310, and the control section 310 acquires the image I (I) transmitted from the photographing section 230 by the electric signal for each frame I (step S101). Frame i is preferably an integer multiple of the frame period Δt described later. Further, as described above, the image I (I) is, for example, a dark-field image. Then, in step S101, the control section 310 stores the acquired image I (I) in a storage element (memory) in the control section 310. The memory element for storing the image I (I) may be a volatile memory such as a register included in the image processing unit 240, or may be a nonvolatile memory disposed outside.

After the process of step S101, the processes of steps S102 to S104 and the process of step S105 are executed in parallel. As will be described later, in step S104, the processing result of step S105 is used.

In steps S102 to S104, the movement amount calculation unit 320 calculates, for example, the position of the car 120 (the total movement amount of the car 120 from the reference position of the luminance mark 150) and the movement speed V of the car 120 as car movement related information. The following is a detailed description.

First, the movement amount calculation section 320 reads the image I (I) of the I-th frame stored in the storage element from the storage element and reads the image I (I-k) of the I-th frame stored in the storage element k-th frame before the I-th frame (k is an integer of 1 or more) from the storage element in step S101, and calculates the movement amount Δy of the car 120 from the I-th frame to the I-th frame based on the difference between the image I (I) and the image I (I-k) (step S102).

As for the calculation of the movement amount Δy of the car 120 in step S102, in fig. 5 described later, a more specific image is supplemented by showing an example of a captured image.

In step S102, the selection method of the image I (I-k) that takes the difference from the latest image I (I) may select the image (k=1) before the I frame or may select the image (k=2 or more integer) before the multi-frame. In the method for calculating the movement amount Δy of the car 120, for example, a cross-correlation function, which is an index of similarity between the image I (I) and the image I (I-k), is calculated, and a y component (component in the same direction as the lifting direction of the car 120) of the peak coordinate position of the cross-correlation function is estimated as the movement amount Δy of the car 120. In addition, the method of estimating the movement amount Δy from the y component of the peak coordinate position is not limited to a specific method. For example, the estimation may be performed based on the peak coordinates of the maximum position, or the estimation may be performed by performing least squares fitting using several points near the maximum position.

Next, the movement amount calculation unit 320 calculates the elapsed time kχΔt from the image I (I-k) to the image I (I), and calculates the movement speed V of the car 120 (movement speed v=Δy/(kχΔt)) by taking the ratio of the movement amount Δy to the time kχΔt (step S103).

The movement amount calculating unit 320 sequentially adds the movement amounts Δy of the car 120 to the reference positions of the luminance marks 150, and calculates the total movement amount of the car 120 from the reference positions, and the reference positions of the luminance marks 150 are recognized as the movement amount calculation references by the luminance mark recognizing unit 330 in step S105 (step S104).

On the other hand, in step S105, the luminance-marker identifying unit 330 calculates reference-position-related information using the luminance markers 150 included in the image I (I) of the I-th frame as the reference for the shift-amount calculation.

More specifically, the luminance mark identifying section 330 reads the image I (I) of the I-th frame from the storage element, and determines whether the luminance mark 150 is present in the image I (I) by performing image identifying processing on the image I (I). When the luminance mark 150 exists in the image I (I), the luminance mark identifying section 330 recalculates the reference position-related information with the luminance mark 150 as a new reference for the shift amount calculation. Specifically, the luminance mark identifying unit 330 calculates a reference position of the luminance mark 150 newly used as a reference for calculation of the movement amount, an ID (ID pattern 820 of fig. 8) assigned to the luminance mark 150, and the like. On the other hand, when the luminance mark 150 is not present in the image I (I), the luminance mark identifying section 330 does not update the reference of the movement amount calculation, and continues to use the reference position-related information calculated by the latest measurement processing.

By performing the processing of step S105 in this manner, the luminance-marker identifying section 330 can calculate the reference-position-related information using the latest luminance marker 150 included in the image I (I) that changes according to the movement of the car 120 as the reference for the movement-amount calculation. When the car 120 (measuring device 110) is lifted up in the y-axis direction, for example, as described specifically with reference to fig. 1, the luminance mark 150-1 becomes a reference for the movement amount calculation until the car 120 reaches the luminance mark 150-2 beyond the luminance mark 150-1, and the reference position-related information with reference to the luminance mark 150-1 is calculated. Further, after the car 120 (measuring device 110) reaches the luminance mark 150-2, until the next luminance mark 150 is reached, the luminance mark 150-2 serves as a reference for calculating the movement amount, and reference position-related information based on the luminance mark 150-2 is calculated.

When step S104 and step S105 are completed, the control unit 310 (or the communication unit 340) transmits the car movement related information calculated in step S102 to S104 and the reference position related information calculated in step S105 to the elevator control unit 130 via the communication unit 340 (step S106). Then, the control unit 310 adds 1 to the value of the frame number "i" (step S107).

Then, the control unit 310 confirms whether or not the measurement device 110 is in a state where power is supplied (step S108). When the power is supplied in step S108 (yes in step S108), the image processing unit 240 repeats the processing in steps S101 to S107, and when the power supply is cut off (no in step S108), the measurement processing ends.

In the measurement processing shown in fig. 4, as described above, the luminance mark 150 (more strictly, the reference position of the luminance mark 150) that is recognized as being present by the image recognition processing of the luminance mark recognition section 330 is set as the reference position, and the movement amount of the car 120 from the reference position is added up to recognize the absolute position between the reference positions of the car 120. Therefore, when the car is running, the error may accumulate during the period until the reference position of the next luminance mark 150 is reached. In this case, when the car 120 reciprocates in a section where there is no reference position, errors may be continuously accumulated all the time, which is undesirable in terms of the measurement accuracy of the absolute position. To eliminate such error accumulation, in the present embodiment, at least one brightness marker 150 is provided between floors. Specifically, for example, when the interval between floors is 4 meters, the setting interval of the luminance mark 150 is set to 4 meters or less.

As described above, in the elevator system 10, by performing the measurement processing by the image processing unit 240 of the measurement system 100 (measurement device 110), when the elevator car 120 moves, the absolute position of the elevator car 120 can be calculated by adding up the relative movement amount Δy from the reference position of the luminance mark 150 as the reference.

Next, a calculation image of the movement amount Δy of the car 120 by the movement amount calculation unit 320 will be described with reference to fig. 5, in addition to the measurement processing described above. As a supplementary explanation associated with a captured image (i)) that is the object of measurement processing, a design of exposure time of the imaging section 230 for preventing occurrence of subject shake in the captured image is explained with reference to fig. 6 and 7.

Fig. 5 is a diagram for explaining a change in a captured image when the car 120 moves. Strictly speaking, as described above, the photographing section 230 reads an optical signal imaged on the photographing surface and converts it into an electrical signal, and the image processing section 240 (control section 310) applies image processing to the electrical signal to generate a photographed image. However, for simplicity, in the following description, the electric signal converted by the photographing section 230 may be replaced with a "photographed image" subjected to image processing by the control section 310 for processing. In fig. 5, a case where the image of the luminance mark 150 is not included in the captured image is illustrated as an example, but the captured image may include the image of the luminance mark 150.

When the guide rail 140 as the subject is photographed from the car 120 moving at the moving speed V, as shown in fig. 5, a deviation occurs between the two photographed images 520-1 of the scattering luminance distribution 510 on the surface of the subject (the surface of the guide rail 140) and the photographed image 520-2 in the moving direction (y-axis direction) at the time point of the time t and the time point of the time (t+k×Δt). Note that Δt represents a frame period, k is an integer value, and represents the number of passes of a unit frame with a predetermined timing as a start point (k=0). At this time, Δy representing the displacement amount of the deviation corresponds to the movement amount Δy of the car 120. Therefore, as described in steps S102 to S104 of fig. 4, the movement amount calculation unit 320 can calculate the movement amount of the car 120 by comparing the captured images between different frames.

As shown in fig. 6, the control section 310 of the image processing section 240 transmits a strobe signal 610 (strobe signals 610-1, 610-2 of fig. 6) to the photographing section 230 every frame period Δt. The photographing section 230 performs exposure only for a time of a pulse width T (exposure time T) in response to the pulse of the gate signal 610 transmitted from the control section 310, and photographs an optical signal imaged on a photographing surface. In the measuring device 110 of the present embodiment, the strobe signal 610 may be transmitted from the control unit 310 to the light transmitting unit 210 in parallel with the transmission of the strobe signal 610 from the control unit 310 to the imaging unit 230, and the light transmitting unit 210 that receives the strobe signal 610 may light the light source only during the exposure time T. By performing such lighting control, the average output power per unit time of the light transmitting unit 210 can be reduced, and thus the effects of suppressing the power and heat dissipation required for driving are obtained.

Fig. 7 is a diagram showing an example of the luminance distribution of a captured image in exposure time. In more detail, an example of the luminance distribution of a photographed image when scattered light emitted from the luminance mark 150 provided on the guide rail 140 is imaged on the photographing part 230 during one exposure time T is shown in fig. 7.

In fig. 7, since the exposure time is set to T, if the start time in the exposure time is set to T, the end time in the exposure time is denoted by t+t. The scattered light intensity distribution 710-1 is the luminance distribution of scattered light on the imaging plane at the start time T within the exposure time T, and the scattered light intensity distribution 710-2 is the luminance distribution of scattered light on the imaging plane at the end time t+t within the exposure time T. As can be seen from comparing the scattered light intensity distributions 710-1 and 710-2 in fig. 7, the luminance distribution of the scattered light imaged on the light receiving surface (imaging surface) of the imaging unit 230 moves in the moving direction (y-axis direction) of the car 120 during the period of the gate signal 610 transmitted from the control unit 310 to the imaging unit 230. As a result, subject shake in the y-axis direction occurs in the captured image 720 during this period (exposure time T).

The subject shake described above is due to "blurring" occurring in the moving direction (y-axis direction) of the photographed image 720 after exposure because images of the scattered light intensity distribution continuously changing from the scattered light intensity distribution 710-1 at the start time T to the scattered light intensity distribution 710-2 at the end time t+t within the exposure time T are accumulated at every moment. That is, in the captured image 720, in proportion to the exposure time T in the capturing section 230, more strictly, only the movement speed V of the car 120 and the exposure time T, that is, the magnitude of v×t, are blurred. Further, if image processing is performed in a state in which the subject shake (blurring) occurs in the captured image 720, there is a conceivable problem that the moving speed or position of the car 120 cannot be accurately calculated.

Regarding the above-described problem, in order to suppress the occurrence of subject shake in the moving direction (y-axis direction) of the car 120, it is necessary to sufficiently reduce (shorten) the exposure time T in consideration of the moving speed V of the car 120. Therefore, in the present embodiment, a time shorter (smaller) than a time obtained from a ratio of the spatial resolution δ _x of the pixel of the imaging unit 230 to the maximum moving speed V _max of the car 120 is set as the exposure time T of the imaging unit 230. That is, the exposure time T is determined by using the required spatial resolution δ _x and the maximum moving speed V _max of the car 120 to satisfy the relationship of "T < δ _x/V_max". Specifically, for example, for an elevator car 120 requiring a maximum moving speed of 300m per minute, when a spatial resolution of 0.5mm is required, it may be required to control the exposure time to 100 μs or less.

(1-3) Characteristics of luminance mark 150

Features of the luminance mark 150 usable in the measurement system 100 of the present embodiment are described in detail below.

First, the shape of the luminance mark 150 is explained.

Fig. 8 is a diagram showing a specific example of the luminance mark 150. In fig. 8, as a specific example of the luminance mark 150 of a different shape, a luminance mark 151 is illustrated in fig. 8 (a), a luminance mark 152 is illustrated in fig. 8 (B), and a luminance mark 153 is illustrated in fig. 8 (C). The features of the respective luminance marks 151 to 153 will be described later, and first, the common structure of the luminance marks 150 will be described.

As shown in the respective views in fig. 8, the luminance mark 150 includes a reference line 810 as a reference of an absolute position and an ID pattern 820 distinguishing the reference position by combining the configurations of bright-dark luminance. The ID pattern 820 has an identification signal different for each pattern. A margin of a predetermined amount or more is provided outside the print area of the luminance mark 150. By providing the blank, even if the car 120 is swung in the vertical direction (x-axis direction) orthogonal to the moving direction (y-axis direction) during traveling, the image pickup unit 230 can recognize the luminance mark 150 without deviating the print area from the image pickup area. That is, even if the car 120 is swayed in the x-axis direction during traveling, the photographing unit 230 may reliably converge the printing area of the luminance mark 150 within the photographing area, and the length of the side in the x-axis direction of the luminance mark 150 may be equal to or less than the length obtained by subtracting the displacement amount of the maximum swaying in the x-axis direction that can occur in the car 120 from the length of the side in the x-axis direction of the photographing area. Specifically, for example, when the measuring device 110 having a photographing area of 13mm is used for the car 120 capable of generating a car shake of 5mm in the x-axis direction, the length of the side of the luminance mark 150 in the x-axis direction is required to be at least 8mm or less.

The luminance marks 150 (luminance marks 151 to 153) of the present embodiment have characteristic luminance variations at least in the x-axis direction. By utilizing this change in luminance, the measuring device 110 can improve the detection accuracy by suppressing the influence of the subject shake to the minimum even when the car 120 moves at a high speed in the y-axis direction. A specific example for explaining the effect of improving the detection accuracy is shown in fig. 9.

Fig. 9 is a diagram showing one example of the luminance distribution of the captured image of the luminance mark 151. As in fig. 7 for the luminance mark 150, fig. 9 shows an example of the luminance distribution of the captured image during the one-time exposure time T for the luminance mark 151 shown in fig. 8 (a). As described above, in fig. 7, when the car 120 moves at a high speed, subject shake in the moving direction (y-axis direction) may occur in the captured image. Specifically, in fig. 9, from the scattered light intensity distribution 910-1 at the start time T within the exposure time T to the scattered light intensity distribution 910-2 at the end time t+t within the exposure time T, images of the scattered light intensity distribution that continuously change from time to time are accumulated, so that subject shake occurs in the moving direction (y-axis direction) of the post-exposure captured image 920. However, the luminance mark 150 (for example, the luminance mark 151) of the present embodiment has a characteristic luminance change in the x-axis direction, so that even if subject shake occurs in the moving direction (y-axis direction) of the car 120 on the captured image 920, the pattern of the luminance change (brightness of the edge) in the x-axis direction is not affected (refer to the captured image 920 of fig. 9). That is, even if subject shake occurs in the y-axis direction in the captured image 920, the measuring device 110 (the image processing section 240) can detect a bright-dark edge provided in the x-axis direction in which subject shake does not occur, and therefore, the detection accuracy of the ID pattern 820 can be improved.

In the luminance mark 150 (luminance marks 151 to 153) of the present embodiment, the interval between the bright and dark luminance changes of the ID pattern 820 is larger than the spatial resolution δx determined by the pixels of the imaging unit 230. This is because, if the interval of the bright-dark luminance change of the ID pattern 820 is smaller (finer) than the spatial resolution δ _x determined by the pixels of the imaging unit 230, the imaging unit 230 cannot distinguish the luminance change. Therefore, specifically, for example, when the spatial resolution δ _x of the photographing part 230 is 0.5mm, the period of the bright-dark luminance change of the ID pattern 820 is at least greater than 0.5mm.

The combination of the ID patterns 820 in the luminance marks 150 (luminance marks 151 to 153) of the present embodiment has a number of combinations sufficient to distinguish the reference position information in the same hoistway. Specifically, for example, when the luminance marks 150 are provided every 4m in a hoistway having a total height of 100m, at least 25 luminance marks 150 are provided, and thus the ID pattern 820 requires a number of combinations of at least 25 patterns or more.

In addition, in the luminance marks 150 (luminance marks 151 to 153) of the present embodiment, the ID pattern 820 has no periodicity in the moving direction (y-axis direction). This is because, even in a place where the luminance mark 150 is provided, the image processing (movement amount calculation processing) by the movement amount calculation unit 320 is performed, and therefore, if the ID pattern 820 of the luminance mark 150 has periodicity in the movement direction (y-axis direction) of the car 120, this periodicity is reflected in the movement amount calculation processing, and thus uncertainty corresponding to the periodicity may occur in the calculated movement amount Δy (and total movement amount) of the car 120, and the movement amount may not be uniquely estimated.

Next, the features of each of the luminance marks 151 to 153 shown in fig. 8 (a) to 8 (C) will be described. Any of these luminance marks 151 to 153 has the features of the luminance mark 150 of the present embodiment described above.

The luminance mark 151 shown in fig. 8 (a) is an example of the luminance mark 150 in which the reference line 810 is separated from the ID pattern 820, and the ID pattern 820-1 of the luminance mark 151 is constituted by a one-dimensional bar code having different shades in the x-axis direction. In the case of the brightness mark 151, by detecting the position of the bright and dark edge in the ID pattern 820-1, information for discriminating the ID of the reference position can be identified. By detecting a position where the luminance difference is equal to or greater than a predetermined threshold value using the light-dark luminance difference as an index, the edges of the light and dark can be recognized. Similarly, by detecting the coordinate (y-coordinate) at which the luminance changes sharply in the y-axis direction, the position of the reference line 810-1 can also be identified.

In the present embodiment, by using the above-described luminance mark 151, the features of the luminance mark 150 of the present embodiment can be provided, and a luminance mark having a simpler structure can be realized.

The luminance mark 152 shown in fig. 8 (B) is an example of the luminance mark 150 after integrating the reference line 810 and the ID pattern 820. The ID pattern 820-2 of the luminance mark 152 is constituted by a two-dimensional bright-dark mosaic pattern in the xy-axis direction, and the reference line 810-2 is constituted as one side of the bright-dark mosaic pattern. As in the case of the ID pattern 820-1 of the one-dimensional bar code having a dark and a light, as shown in fig. 8 (a), a dark and a light mosaic pattern such as the ID pattern 820-2 can be detected by detecting a brightness difference, and as a result, a combination of patterns can be recognized. Further, by detecting the corner positions of the rectangle of the luminance mark 152, the position of the reference line 810-2 can be determined.

In the present embodiment, when the above-described luminance mark 152 is used, the number of pattern combinations can be increased in the y-axis direction in the two-dimensional ID pattern 820-2 of the bright-dark mosaic type as compared with the ID pattern 820-1 formed of the one-dimensional bar code in the x-axis direction, and thus the writable information amount (for example, layer height information and the like) can be increased. In addition, even for a part of pattern defects caused by stains adhering to the pattern, partial peeling of the pattern, saturation of pixel values due to external light, and the like, a redundancy configuration of the pattern can be easily obtained by increasing the number of pattern combinations, and thus a luminance mark with higher robustness can be realized.

The luminance mark 153 shown in fig. 8 (C) is an example of the luminance mark 150 after integrating the reference line 810 and the ID pattern 820. The ID pattern 820-3 of the luminance mark 153 is composed of numerals and characters. In the case of using the luminance mark 153, before measuring the position of the car 120, for example, the image processing unit 240 learns the respective ID patterns 820-3 by processing such as machine learning, and assigns and stores the position information to the feature points of the respective ID patterns 820-3 obtained by the learning, so that the image processing unit 240 can read the information (numerals or characters) included in the ID patterns 820-3 in the captured image when measuring the position of the car 120. Further, the reference line 810-3 is configured as one side of the rectangle of the luminance mark 153, like the reference line 810-2, and thus the position can be determined by detecting the corner position of the rectangle of the luminance mark 153.

In the present embodiment, when the above-described luminance mark 153 is used, the person can easily recognize the information included in the ID pattern 820-3 from the captured image of the luminance mark 153 of the imaging unit 230, and therefore, the luminance mark 153 can be used for other purposes than the object of the reading process of the measuring device 110. For example, the luminance mark 153 can be used for applications for distinguishing the number and positions of members such as the guide rail 140 at the time of installation, construction, or inspection of the guide rail 140.

In addition, in the measurement system 100 of the present embodiment, in order to improve the recognition accuracy of the luminance mark 150, in addition to the ID pattern 820 formed by the tape or the score provided manually, stains or scratches that naturally adhere to the guide rail 140 can be used as the ID pattern 820. In this case, stains and scratches may be stored in the measuring device 110 or the elevator control part 130 in advance, and may be used by associating the stains and scratches with position information thereof.

Next, the size of the luminance mark 150 is explained.

In the present embodiment, the length L _mark of the side in the y-axis direction of the luminance mark 150 is configured to be equal to or less than a length obtained by subtracting a size obtained by multiplying the maximum moving speed V _max of the moving body (car 120) by the frame time Δt (see fig. 6) corresponding to the generation cycle of the gate signal 610 from the length L _obs of the side in the y-axis direction of the imaging region of the imaging unit 230. That is, the relationship of "L _mark≤L_obs-V_max ×Δt" is established (the equal sign of the above inequality can be excluded). With this configuration, the image processing section 240 can acquire a captured image of the entire luminance mark 150 in at least any one of the frames between two consecutive frames. The necessity for the size of the luminance mark 150 to satisfy the above-described relational expression is described with reference to fig. 10.

Fig. 10 is a diagram for explaining a dimensional relationship between the luminance mark 150 and the imaging region of the measuring apparatus 110. In fig. 10, an example is shown in which, in the case where the length L _mark of the side in the y-axis direction of the luminance mark 150 does not satisfy the structure of the relation "L _mark≤L_obs-V_max ×Δt" shown in the previous paragraph, a captured image of the complete luminance mark 150 cannot be obtained in at least one frame between two consecutive frames. The image processing unit 240 (control unit 310) sets the frame period of the electric signal for acquiring the captured image from the capturing unit 230 to Δt.

As shown in fig. 10, when two consecutive frames (first frame and second frame) pass, the photographing region 1010 of the measuring device 110 (photographing part 230) moves in the y-axis direction, which is the moving direction of the car 120. Specifically, in fig. 10, the shot region 1010-1 at the first frame start time t is moved to the shot region 1010-2 at the second frame start time t+Δt.

Here, the maximum movement distance L _max between frames can be expressed as a product of the maximum movement speed V _max of the car 120 and the frame period Δt (L _max＝V_max ×Δt). When the length of the side in the moving direction (y-axis direction) of the imaging region 1010 is L _obs, the length of the side in the y-axis direction of the region where the imaging regions 1010 overlap in two consecutive frames is given by "L _obs-L_max".

Fig. 10 illustrates, for example, a case where the length "L _obs-L_max" of the side in the moving direction (y-axis direction) of the repetitive region is smaller than the size (length of the side in the moving direction) L _mark of the luminance mark 150, that is, a case where the relationship of "L _mark>L_obs-V_max ×Δt" is established, and at this time, as illustrated in fig. 10, in either one of the first frame (time t) and the second frame (time t+Δt), the luminance mark 150 may not be completely converged within the photographing region 1010, and only an image of a part of the luminance mark 150 is photographed, with the result that the image processing section 240 fails to read the luminance mark 150 from the photographed image.

As described above, in contrast to the failure example of fig. 10, in the present embodiment, in order to completely capture the entire luminance mark 150 in the captured image of at least any one of two consecutive frames (time t, time t+Δt), the size L _mark of the luminance mark is required to be "L _obs-V_max ×Δt" or less. As a specific example, when the luminance mark 150 is recognized by using the measuring device 110 in which the frame period (Δt) is 1mm sec and the length (L _obs) of the side in the moving direction (y-axis direction) of the photographing region 1010 is 13mm, the length (L _mark) of the side in the moving direction (y-axis direction) at the luminance mark 150 is required to be at least 8mm or less for the car 120 in which the required maximum moving speed (V _max) is 300m per minute.

In the present embodiment, a plurality of luminance marks 150 indicating the same ID pattern 820 may be arranged for redundancy purposes. In this case, the above-described requirement "L _mark≤L_obs-V_max ×Δt" does not need to be satisfied for the size of the entire plurality of luminance marks 150 arranged, but the above-described requirement is required to be satisfied in at least one or more luminance marks 150 among the plurality of luminance marks 150 representing the same ID pattern 820. In addition, in view of ease of installation, for example, when the luminance mark 150 is attached to the guide rail 140 by a sticker or the like, only the luminance mark 150 printed inside the sticker may satisfy the above-described requirement, and the size of the sticker may be a size sufficiently larger than such a luminance mark 150.

As described above, according to the measuring system 100 of the present embodiment, when the moving object (the elevator car 120) moves, the measuring device 110 mounted on the moving object performs the measurement processing shown in fig. 4 on the captured image of the luminance mark 150 having the characteristics described with reference to fig. 8 to 10 and the like, and thus can calculate the absolute position information of the moving object on the moving path at high speed and with high accuracy. That is, according to the measurement system 100 of the present embodiment, the reference position provided in the hoistway is identified with high accuracy from the moving body moving at high speed, and the absolute position of the moving body in the hoistway can be measured with high accuracy at high speed by sequentially accumulating the moving distances of the moving body from the reference position. The predetermined control unit (elevator control unit 130) can perform operation control of the mobile body and control of the safety device based on the absolute position information of the mobile body calculated by the measuring device 110.

(1-4) Control of return operation of the moving body at the time of Power recovery

Further, by using the measurement system 100 of the present embodiment, the elevator system 10 can realize operation control for moving the moving body to a predetermined return position when power recovery after power failure or the like occurs (specifically, return operation control for returning the elevator car 120 stopped by the power failure to the nearest floor).

Fig. 11 is a conceptual diagram for explaining a procedure of return operation control of the elevator car 120. Referring to fig. 11, a process of returning the elevator car 120 stopped at the stop position 1111 due to power interruption to the nearest floor 1120 when power is restored will be described.

First, at the time of installation of the elevator system 10, a floor level table associating the reference position 1112 provided with the brightness mark 150 with the floor position 1113 of each floor is prepared in advance, and for example, the elevator control unit 130 stores the floor level table in advance. The reference position 1112 is a height corresponding to the reference line 810 provided for each of the luminance marks 150, and the floor position 1113 is a height of the measuring device 110 when the car 120 stops on a corresponding floor (for example, the floor 1120).

However, in the elevator system 10, when power interruption such as a power failure occurs, the operation of the car 120 or the like is stopped, and at this time, there is a possibility that the position information of the car 120 measured by the measuring device 110 before the power interruption is lost due to the power interruption. Therefore, when the elevator control unit 130 returns the car 120 to the nearest floor 1120 and resumes the car control at the time of power restoration, a large error may occur if the car 120 is returned to the nearest floor 1120 based on the position information measured before the power supply is turned off.

In order to solve the above-described problem, in the elevator system 10 of the present embodiment, when recovering from the power supply cut-off, the elevator control section 130 first raises or lowers the car 120 from the position at the time of recovering the power (the stop position 1111 of the power supply cut-off), and searches for the luminance mark 150 located at the shortest distance. That is, in fig. 11, as indicated by an arrow 1131, the car 120 is moved from the stop position 1111 to the reference position 1112 where the brightness mark 150 is provided.

Next, the measuring device 110 reads the ID pattern 820 using the combination of the brightness change from the captured image of the brightness mark 150 having the reference position 1112, acquires the position information about the reference position 1112 (in other words, the reference line 810 of the brightness mark 150), and sends the position information to the elevator control unit 130.

The elevator control unit 130 calculates the travel distance to the floor position 1113 of the measuring device 110 when the car 120 is moved to the nearest floor 1120, based on the position information of the reference position 1112 acquired by the measuring device 110 and a pre-stored floor height table. Accordingly, the elevator control unit 130 can accurately return the car 120 to the nearest floor 1120 by moving the car 120 by the calculated movement distance as indicated by an arrow 1132 in fig. 11.

(2) Embodiment 2

Fig. 12 is a diagram showing a measurement device 1200 according to embodiment 2 of the present invention centering on an internal configuration example of an imaging unit 1220. The measurement device 1200 of embodiment 2 is characterized by including a robust imaging unit 1220 that can maintain the imaging magnification in the imaging unit 230 with respect to the shake in the z-axis direction (see fig. 1) of the car 120, but other configurations are the same as the measurement device 110 of embodiment 1, and therefore detailed description thereof is omitted.

In fig. 12, the light rays of the scattered light from the guide rail 140 and the luminance mark 150 are shown by broken lines with arrows (for example, the scattered light 1211 to 1213). As shown in fig. 12, the imaging section 1220 images scattered light from the guide rail 140 and the luminance mark 150 to the photographing section 230. Specifically, the imaging section 1220 is configured to include an objective lens 1221 (first lens), an aperture 1222, and a condenser lens 1223 (second lens). The objective lens 1221 is disposed opposite the guide rail 140, and condenses scattered light scattered by the guide rail 140. The diaphragm 1222 restricts the amount of scattered light (scattered light 1211 to 1213) collected by the objective lens 1221. The condenser lens 1223 is disposed between the diaphragm 1222 and the imaging unit 230, condenses the scattered light whose light quantity is limited by the diaphragm 1222, and transmits the condensed scattered light to the imaging surface of the imaging unit 230.

In the imaging unit 1220 of the present embodiment, in order to eliminate the influence of the change in magnification when the guide rail 140, which is the subject (detection object), is relatively dithered with respect to the car 120 in the z-axis direction, at least the object side (guide rail 140 side) is telecentric optically arranged, and in order to suppress the geometric aberration generated in the imaging unit 230, images are formed on the imaging unit 230 through two or more lenses. In addition, the imaging unit 1220 may have a telecentric optical configuration on the image side (imaging unit 230 side), and in this case, the imaging unit 1220 functions to expand the dimensional tolerance in the z-axis direction (the mounting tolerance in the z-axis direction) when the imaging unit 230 is mounted.

That is, in the measuring apparatus 1200 of the present embodiment, the center of the imaging surface of the imaging section 230, the optical axis of the condenser lens 1223, the center of the diaphragm 1222, and the optical axis of the objective lens 1221 are arranged on the same straight line, and the diaphragm 1222 is arranged at the focal position on the imaging section 230 side of the objective lens 1221, and is arranged at the focal position on the objective lens 1221 side of the condenser lens 1223.

As shown in fig. 12, in the present embodiment, scattered light from the guide rail 140 passes through the objective lens 1221 and is then imaged on the imaging surface of the imaging unit 230 via the condenser lens 1223, and the scattered light 1211 to 1213 of the scattered light is the principal ray of the imaging optical system. That is, the objective lens 1221, the aperture 1222, and the condenser lens 1223 are arranged such that the scattered light rays 1211 to 1213 pass through the center of the aperture 1222, such that the scattered light rays 1211 to 1213 are always emitted from the scattering surface of the guide rail 140 in parallel with the optical axis of the objective lens 1221, and are always incident on the photographing part 230 in parallel with the optical axis of the condenser lens 1223.

As described above, according to the measuring apparatus 1200 of the present embodiment, even if the image of the guide rail 140 is dithered in the optical axis direction (z-axis direction), the magnification of the image imaged on the imaging surface of the imaging unit 230 can be kept unchanged, and even if the mounting position of the imaging unit 230 in the z-axis direction is shifted, the magnification of the image imaged on the imaging surface of the imaging unit 230 can be kept unchanged. As a result, dimensional tolerances at the time of mounting the imaging section 2220 and the photographing section 230 can be made large, and an optical system with higher robustness can be constituted. In addition, by using two lenses including the objective lens 2221 and the condenser lens 2223 for the imaging section 2220, it is also possible to expect to reduce the influence of the geometric aberration of the imaging section 2220 generated in the photographing section 230.

In the present embodiment, the imaging unit 220 may be configured as a glass lens, with both sides of the objective lens 2221 being spherical, or with one side of the objective lens 2221 being spherical and the other side being planar. The surface of the condenser lens 2223 through which the light passes may be formed in a spherical shape on both sides, or may be formed in a spherical shape on one side and a planar shape on the other side, and may be formed as a glass lens. With such a configuration, the imaging section 2220 of the measuring device 1200 of the present embodiment can be configured to be less expensive and have higher durability.

(3) Embodiment 3

Fig. 13 is a diagram illustrating a measurement apparatus 1300 according to embodiment 3 of the present invention centering on an example of the internal configuration of an imaging unit 1320. The measurement apparatus 1300 of embodiment 3 has the same configuration as the measurement apparatus 1200 of embodiment 2 except that part of the internal configuration of the imaging section 1320 is different, and a detailed description of points common to embodiment 2 is omitted.

In fig. 13, the light rays of the scattered light from the guide rail 140 and the luminance mark 150 are shown by broken lines with arrows (for example, scattered light 1311 to 1313). As shown in fig. 13, the imaging section 1320 images scattered light from the guide rail 140 and the luminance mark 150 to the photographing section 230. Specifically, as with the imaging unit 1220 of embodiment 2 shown in fig. 12, the imaging unit 1320 is configured to include an objective lens 1321 (first lens), an aperture 1322, and a condenser lens 1323 (second lens), and the imaging unit 1320 includes a mirror 1324 as a structure inherent to the present embodiment.

Here, the configuration and the function of the objective lens 1321, the diaphragm 1322, and the condenser lens 1323 are the same as those of the objective lens 1221, the diaphragm 1222, and the condenser lens 1223 shown in fig. 12, respectively, and telecentric optical arrangement is performed on the object side (the guide rail 140 side) and telecentric optical arrangement is performed on the image side (the imaging unit 230 side). Further, the mirror 1324 is disposed to face the guide rail 140, and the scattered light scattered by the guide rail 140 is reflected positively toward the objective lens 1321.

Since the measuring device 1300 of the present embodiment has the above-described structure, the same effects as those of the measuring device 1200 of embodiment 2 can be obtained. Further, the measuring device 1300 of the present embodiment can realize a more compact structure by using the mirror 1324. That is, as can be seen from a comparison between fig. 13 and 12, in the measuring apparatus 1300, the imaging unit 1320, the imaging unit 230, and the image processing unit 240 (not shown) can be disposed above the car 120, and thus the measuring apparatus 1300 can be placed on the upper portion of the car 120 without using a special jig.

(4) Embodiment 4

Fig. 14 is a diagram showing a measurement device 1400 according to embodiment 4 of the present invention centering on an example of the internal structure of an imaging section 1420. The measurement device 1400 of embodiment 4 is different from the measurement device 1200 of embodiment 2 in which the imaging unit 1220 is arranged in a dark-field optical arrangement, in that the imaging unit 1420 is arranged in a bright-field optical arrangement, but the measurement device 1400 of embodiment 4 has basically the same configuration as that of embodiment 2 except that a detailed description of common points with embodiment 2 is omitted.

In fig. 14, the light rays of the scattered light from the guide rail 140 and the luminance mark 150 are shown by broken lines with arrows (for example, scattered light 1411 to 1413). As shown in fig. 14, the imaging unit 1420 is arranged in a bright field optical arrangement, and images scattered light of illumination light from the light transmitting unit 210 to the imaging unit 230. Specifically, the imaging section 1420 is configured to include an objective lens 1421 (first lens), an aperture 1422, and a condenser lens 1423 (second lens). The objective lens 1421 is disposed on the guide rail 140 in a direction that regular reflects the light emitted from the light transmitting unit 210 of the photographing unit 230, and condenses the scattered light in the guide rail 140. The objective lens 1421, the diaphragm 1422, and the condenser lens 1423 have the same structure and function as the objective lens 1221, the diaphragm 1222, and the condenser lens 1223 shown in fig. 12, respectively, and are arranged telecentrically on the object side (the guide rail 140 side) and also on the image side (the imaging unit 230 side).

Since the measuring device 1400 of the present embodiment has the above-described structure, the same effects as those of the measuring device 1200 of embodiment 2 can be obtained. Further, in the measuring apparatus 1400 of the present embodiment, by arranging the imaging section 1420 in the bright field optical arrangement, the amount of scattered light incident on the imaging section 230 can be increased, and therefore, the effect of improving the processing accuracy of the movement amount calculation processing and the luminance mark recognition processing performed by the image processing section 240 can be obtained.

(5) Embodiment 5

In this embodiment, a measurement system 1500 having a configuration in which the internal configuration of the measurement device 110 (the light transmission unit 210, the imaging unit 220, the imaging unit 230, and the image processing unit 240) and the luminance mark 150 in the measurement system 100 of embodiment 1 are made redundant, respectively, will be described.

Fig. 15 is a diagram showing a configuration example of a measurement system 1500 according to embodiment 5 of the present invention. As shown in fig. 15, the measuring system 1500 includes a measuring device 1510 having two or more measuring units 1511 (measuring units 1511-a and 1511-B, respectively), a determining unit 1520 disposed between the measuring device 1510 and the elevator control unit 130, and two or more luminance marks 150 (luminance marks 150-a and 150-B, respectively) attached to at least two or more positions of the guide rail 140. Although the measurement system 1500 shown in fig. 15 has a double structure and a redundancy structure, the redundancy structure of the measurement system 1500 is not limited to the double structure in the present embodiment, and may be a triple or more redundancy structure.

In the measuring device 1510, the measuring units 1511-a and 1511-B have the same internal structure as the measuring device 110. Specifically, the measurement section 1511-A includes a light transmission section 210-A, an imaging section 220-A, a photographing section 230-A, and an image processing section 240-A, and the measurement section 1511-B includes a light transmission section 210-B, an imaging section 220-B, a photographing section 230-B, and an image processing section 240-B.

In the measuring device 1510 configured as described above, the measuring units 1511-a and 1511-B perform the same measuring process as the measuring device 110 on the luminance mark 150 (the luminance mark 150-a in the case of the measuring unit 1511-a and the luminance mark 150-B in the case of the measuring unit 1511-B) as the imaging object of each measuring unit 1511 among the two or more luminance marks 150 attached to at least two or more positions of the guide rail 140, respectively. That is, the light transmitting section 210 irradiates the outgoing light to the luminance mark 150 as the subject, the imaging section 220 images the scattered light of the luminance mark 150 on the imaging surface of the imaging section 230, the imaging section 230 converts the optical signal coupled to the imaging surface into an electric signal corresponding to the luminance of the pixel, and the image processing section 240 calculates information (car movement related information) related to the movement of the car 120 and information (reference position related information) related to the reference position provided to the luminance mark 150 as the subject based on the captured image generated by performing image processing on the electric signal. However, as points different from the measuring device 110, the respective measuring sections 1511-a, 1511-B send the calculation results of the respective image processing sections 240 to the determining section 1520 instead of the elevator control section 130.

Then, the determination unit 1520 performs comparison processing described in the next stage on the signal information (car movement related information and reference position related information) transmitted from the plurality of measurement units 1511 (in detail, the image processing unit 240) of the measurement device 1510, respectively, to determine an abnormality related to the plurality of measurement units 1511 and the luminance mark 150.

As the above-described comparison processing, the determination section 1520 determines whether or not at least two or more pieces of signal information received from the measurement device 1510 are identical. When the two or more pieces of signal information are determined to be identical by this determination, the determination unit 1520 can determine that the measuring device 1510 and the luminance mark 150 operate normally. On the other hand, when it is determined by this determination that any signal information is different from other signal information, the determination unit 1520 can determine that there is an abnormality in at least one of the measurement device 1510 or the luminance mark 150.

In the present embodiment, "the same signal information" may mean that the contents of the signal information to be compared are identical, but may mean that the contents of the signal information to be compared are almost identical (substantially identical). As a case of perfect agreement, for example, the position of the car 120-a sent from the image processing unit 240-a and the position of the car 120-B sent from the image processing unit 240-B have the same value. In addition, as a case of substantial coincidence, for example, a difference between the position of the car 120-a sent from the image processing unit 240-a and the position of the car 120-B sent from the image processing unit 240-B is within a predetermined range (for example, a range of allowable errors).

In addition, when the measuring device 1510 has three or more measuring units 1511, in the comparison processing of the determining unit 1520, for example, it is determined whether or not all the paired signal information is the same, and when it is determined that all the paired signal information is the same, it is determined that the operation is performed normally, and when it is determined that one or more paired signal information is different, it is determined that at least one of the measuring device 1510 or the luminance flag 150 is abnormal.

As a result of the comparison processing, when it is determined that the measuring device 1510 and the luminance flag 150 are operating normally, the determining unit 1520 transmits signal information (which may be one of the same signal information) received from the measuring unit 1511 and signal information (information indicating normal determination) indicating a determination result that the measuring unit 1511 is operating normally to the elevator control unit 130.

On the other hand, when it is determined that at least one of the measuring device 1510 and the luminance mark 150 is abnormal as a result of the comparison processing, the determining unit 1520 transmits signal information (information indicating an abnormality determination) indicating a determination result of the abnormal operation performed by the measuring unit 1511 to the elevator control unit 130. In addition to the above-described determination of the presence or absence of an abnormality, the determination unit 1520 may identify the type of abnormality by analyzing information on the captured images acquired by the respective measurement units 1511, information on the movement of the car 120 (car movement-related information), information on the reference position of the luminance mark 150 (reference position-related information), and the like. In the analysis method, since a known analysis method can be appropriately used, detailed description is omitted, but specifically, by identifying the kind of abnormality, for example, damage of a component of the measuring device 1510, abnormal vibration due to loosening or damage of the mounting jig, deviation of the mounting position, inclination, corrosion, contamination of the guide rail 140, adhesion of foreign matter, defect of the luminance mark 150, or the like can be detected.

As described above, according to the measurement system 1500 of the present embodiment, by employing the redundancy structure, even when an abnormality such as a failure, dirt, or defect occurs in the measurement device 1510 (measurement unit 1511) or the luminance mark 150, the occurrence of the abnormality can be safely detected without causing an obstacle to the operation of the elevator car 120. Further, when the occurrence of an abnormality is detected, the kind of abnormality can be identified by analyzing the information acquired from the measuring device 1510, and thus an appropriate recovery operation can be rapidly performed.

(6) Other embodiments

In each of embodiments 1 to 5, the case where the present invention is applied to the measuring device for the elevator car 120 in the elevator system has been described, but the present invention is not limited to this, and can be widely applied to various other systems, devices, methods, and programs.

For example, the measuring device 110 of embodiment 1 (the measuring device of other embodiments may be applied not only to the operation of an elevator but also to the use of detecting a position or a speed with high accuracy in a vehicle traveling at a high speed such as an automobile or a train. For example, in an automatically driven vehicle, the measuring device 110 can be applied for the purpose of position monitoring/speed monitoring on an expressway, or for the purpose of highly accurate positioning in a parking lot, a gas station, a charging station, or the like.

Fig. 16 is a diagram showing a configuration example of a vehicle positioning system 1600 in which the measuring device 110 is applied to a vehicle. Fig. 16 (a) shows an example of adhering the luminance mark 150 to the road surface 1620, and fig. 16 (B) shows an example of adhering the luminance mark 150 to the wall 1630 of the expressway.

As shown in fig. 16, in the vehicle positioning system 1600, the measuring device 110 is arranged at a side portion or an upper portion of a vehicle 1610 (for example, an automobile or a train), and the vehicle 1610 travels in a road surface 1620. The measurement device 110 outputs signal information useful for controlling the operation of the vehicle 1610 to a vehicle control unit (not shown). The vehicle control unit is provided for safely operating/stopping the vehicle 1610 that is automatically driven, for example.

The luminance mark 150 indicating the reference position in the road is attached to a predetermined stationary structure (the road surface 1620 in fig. 16 (a) and the wall surface 1630 in fig. 16 (B)) existing in the vicinity of the vehicle 1610. Although only one luminance mark 150 is shown in fig. 16, in practice, a plurality of luminance marks 150 may be arranged on a stationary structure along the moving direction of a moving body, each luminance mark 150 including a corresponding reference line 810 and an ID pattern 820. Specifically, for example, the luminance mark 150 is attached to a wall surface 1630 in front of a signal lamp that needs to safely stop the vehicle 1610, or to a road surface 1620 such as a parking lot or a gas station that needs to accurately position and stop the vehicle 1610. For example, when the application object of the measuring device 110 is a train, the luminance mark 150 may be arranged along a track along which the train travels.

By applying the measuring device 110 to an autonomous vehicle (vehicle 1610) as described above, the vehicle positioning system 1600 of fig. 16 (a) can measure the position of the vehicle 1610 with high accuracy using the luminance mark 150 arranged on the road surface 1620, and thus can contribute to control of stopping the vehicle 1610 at a prescribed destination (parking lot, gas station, charging station, etc.) with high accuracy. Similarly, the vehicle positioning system 1600 of fig. 16 (B) can accurately measure the position of the vehicle 1610 using the luminance mark 150 disposed on the wall surface 1630, and thus can contribute to control to safely stop the vehicle 1610 at a predetermined place (immediately before a signal lamp or the like).

For example, the measuring device 110 of embodiment 1 (may be the measuring device of another embodiment) can be applied to control the operation of a crane.

Fig. 17 is a diagram showing a configuration example of a crane positioning system 1700 in which the measuring device 110 is applied to a crane. In the crane positioning system 1700 shown in fig. 17, the measuring device 110 is arranged at the side or upper portion of the crane 1710 that runs in the 1-axis direction along the rail 1720. In fig. 17, a track 1720 corresponds to a stationary structure on which a luminance mark 150 is disposed, and the luminance mark 150 is disposed along the moving direction of the crane 1710.

In the crane positioning system 1700, the measuring device 110 photographs the wall surface of the track 1720, measures the movement amount and speed of the crane 1710 (information on the movement of the crane 1710), and acquires information on the reference position of the luminance mark 150 by reading the luminance mark 150 stuck on the track 1720. A crane control unit (not shown) of the crane 1710 monitors the operation of the crane 1710 based on the information (i.e., information on the movement of the crane 1710 and information on the reference position of the luminance mark 150) useful for controlling the operation of the crane 1710, and detects a positional abnormality and a speed abnormality.

By applying the measuring device 110 to the crane 1710 as described above, the crane positioning system 1700 can improve the safety of the operation control of the crane 1710 in the operation control of the crane 1710.

The above-described embodiments are for the purpose of easily explaining the present invention, and do not limit the scope of the present invention. In addition, with respect to a part of the structure of each embodiment, addition, deletion, substitution, and the like of other structures may be performed. The above-described structures, functions, processing units, and the like may be partially or entirely implemented by hardware, for example, by an integrated circuit design or the like. The above-described structures, functions, and the like may be interpreted as programs in which the respective functions are realized by a processor, and the functions may be realized in the form of software by executing the programs. Information such as programs, tables, and files for realizing the respective functions can be placed in a recording device such as a memory, a hard disk, and an SSD (Solid STATE DRIVE), or a recording medium such as an IC card, an SD card, and a DVD.

The control lines and information lines necessary for explanation are shown in the figure, but the control lines and information lines are not limited to those necessary for the production. Virtually all structures can be considered interconnected.

Description of the reference numerals

10. Elevator system

100. Measuring system

110. Measuring device

120. Elevator lift-cabin (Car)

130. Elevator control unit

140. Guide rail

150 (151-153) Brightness mark

210. Optical transmitter

220. Image forming section

230. Image pickup unit

240. Image processing unit

310. Control unit

320. Movement amount calculation unit

330. Luminance mark recognition unit

340. Communication unit

510. Scattering luminance distribution

520. Shooting an image

610. Gating signal

710. 910 Scatter light intensity distribution

720. 920 Capturing an image

810. Datum line

820 ID pattern

1010. Shooting area

1111. Stop position

1112. Reference position

1113. Floor position

1120. The nearest floor

1200. 1300, 1400 Measuring device

1211-1213, 1311-1313, 1411-1413 Scatter light

1220. 1320, 1420 Imaging section

1221. 1321, 1421 Objective

1222. 1322, 1422 Aperture

1223. 1323, 1423 Condenser lens

1324. Mirror

1500. Measuring system

1510. Measuring device

1511. Measuring part

1520. Determination unit

1600. Vehicle position locating system

1610. Vehicle with a vehicle body having a vehicle body support

1620. Road surface

1630. Wall surface

1700. Crane positioning system

1710. Crane with crane body

1720. And a guide rail.

Claims

1. A measuring device, arranged on a moving body moving on a moving path and measuring the position of the moving body, characterized in that it comprises:

a light transmitting unit that transmits light for irradiating a stationary structure disposed on the moving path in a first direction parallel to the moving direction of the moving body in response to a strobe signal generated at a predetermined period;

an imaging unit that images the scattered light from the stationary structure generated by the light on a shooting surface;

an imaging unit that acquires a light signal of the scattered light imaged on the imaging surface within an exposure time specified by the strobe signal and converts the light signal into an electrical signal; and

an image processing unit that generates the strobe signal at the predetermined period, performs image processing on the electrical signal converted by the imaging unit to generate an image, and calculates information related to the absolute position of the moving body based on the image.

The image processing unit comprises:

a marker recognition process in which, when the captured image includes an image of a marker disposed on the stationary structure, a reference line representing a reference of an absolute position of the marker is determined using a change in brightness in a second direction perpendicular to the first direction in the captured image; and

A movement amount calculation process is performed to calculate the movement amount of the moving body from the reference line determined by the marker recognition process.

2. The measuring device according to claim 1, characterized in that

The exposure time is set to a value smaller than a time calculated from a ratio between a spatial resolution of an image formed on the imaging plane and a maximum moving speed of the moving object.

3. The measuring device according to claim 1, characterized in that

In the movement amount calculation process, the image processing unit generates the captured image of each frame from the electrical signal converted by the imaging unit at a frame period equivalent to the generation period of the strobe signal.

In the generated captured images of the plurality of frames, a deviation in an image between a first measurement object image included in a captured image of a previous first frame and a second measurement object image included in a captured image of a second frame subsequent to the first frame is calculated, thereby calculating a moving distance of the moving object from the first frame to the second frame.

The moving speed of the moving object is calculated based on the ratio of the calculated moving distance to the time difference between the first frame and the second frame.

4. The measuring device according to claim 1, characterized in that

The imaging unit includes a first lens, which focuses scattered light from the stationary structure;

an aperture that limits the amount of the scattered light obtained after focusing by the first lens; and

a second lens disposed between the aperture and the imaging surface and configured to focus the scattered light whose light quantity is limited by the aperture,

At least the first lens disposed on the stationary structure side is optically arranged in a telecentric manner.

5. A measuring system for measuring the position of a moving object moving on a moving path, characterized in that it comprises:

a measuring device, the measuring device being arranged on the moving body; and

a marker, wherein the marker is disposed on a stationary structure arranged along a first direction parallel to the moving direction of the moving body on the moving path, and at least one marker is disposed at predetermined intervals along the first direction,

The measuring device comprises:

a light transmitting unit that transmits light for irradiating a stationary structure arranged on the moving path in a first direction parallel to the moving direction of the moving body in response to a strobe signal generated at a predetermined period;

an image processing unit that generates the strobe signal at the predetermined period, performs image processing on the electrical signal converted by the imaging unit to generate an image, and calculates information related to the absolute position of the moving object based on the image.

The image processing unit comprises:

Marker recognition processing, in which, when the captured image contains an image of any of the marks, a reference line representing a reference of the absolute position of the mark is determined by using changes in brightness in a second direction perpendicular to the first direction in the captured image; and

6. The measuring system according to claim 5, characterized in that

The moving body is an elevator car moving in a hoistway in an elevator system.

At least one of the markings is provided on the stationary structure disposed in the hoistway between each floor along the first direction.

7. The measuring system according to claim 5, characterized in that

The length of the side of the mark in the first direction is less than the length obtained by subtracting the value obtained by multiplying the maximum moving speed of the moving body by the frame time corresponding to the generation period of the selection signal from the length of the side of the imaging area of the imaging unit in the first direction.

8. The measuring system according to claim 5, characterized in that

The length of the side of the mark in the first direction is 8 mm or less.

9. The measuring system according to claim 5, characterized in that

The length of the side of the mark in a second direction perpendicular to the first direction is set to be less than the length obtained by subtracting the maximum shaking displacement that can be generated on the moving body in the second direction from the length of the side of the imaging area of the imaging unit in the second direction.

10. The measuring system according to claim 5, characterized in that

The marks arranged at different positions on the moving path in the first direction respectively have:

The reference line as a reference for the absolute position of the mark; and

The ID pattern is a pattern that uses a combination of light and dark brightness changes that are different for each of the marks to represent the absolute position information of the reference line.

In the mark recognition process, the image processing unit recognizes the ID pattern assigned to the mark relative to the image of the mark contained in the captured image, and performs a decoding process, wherein the decoding process obtains the absolute position information represented by the ID pattern from the recognized ID pattern.

11. The measuring system according to claim 10, characterized in that

In the mark, the minimum period of light and dark brightness changes in the ID pattern is greater than the spatial resolution of the image imaged on the shooting surface, and the number of combinations of light and dark brightness changes in the ID pattern is greater than the total number of the marks set at different positions in the first direction on the moving path.

12. The measuring system according to claim 10, characterized in that

The ID pattern given to the mark is composed of a combination of light and dark brightness changes arranged in a one-dimensional arrangement in the first direction,

In the mark recognition process, the image processing unit performs a decoding process of the ID pattern using the light-dark brightness change in the mark in the first direction as an index.

13. The measuring system according to claim 10, characterized in that

The ID pattern given to the mark is composed of a combination of light and dark brightness changes arranged in a two-dimensional arrangement in the first direction and in a second direction perpendicular to the first direction,

In the mark recognition process, the image processing unit performs a decoding process of the ID pattern using the light and dark brightness changes in the mark in the first direction and the second direction as an index.

14. The measuring system according to claim 10, characterized in that

The image processing unit learns the ID pattern assigned to the marker before performing the decoding process, assigns the corresponding absolute position information of the marker to the feature point of each ID pattern obtained by learning and stores the absolute position information,

In the marker recognition process, the feature point recognition process is performed on the captured image, and the ID pattern decoding process is performed using the feature point recognized in the recognition process as an index.