Vehicle-mounted speed measurement equipment, positioning speed measurement method and train

Abstract

The invention discloses a vehicle-mounted speed measuring device, a positioning speed measuring method and a train, the vehicle-mounted speed measuring device comprises a processor, a bearing seat, a photoelectric detector, a light barrier, a lens and an optical sensor, the photoelectric detector, the light barrier, the lens and the optical sensor are arranged on the bearing surface of the bearing seat, and signal light emitted by a VLC light source passes through a first through hole in the light barrier, then passes through the lens and then passes through a second through hole in the light barrier; a projection is formed on the optical sensor, the processor determines that the train arrives at the first position according to the projection, determines that the train arrives at the first position, receives a first emission moment sent by the photoelectric detector, determines that the train arrives at the second position, receives a second emission moment sent by the photoelectric detector, and determines that the train arrives at the second position according to a preset height difference, a preset proportion and a time difference. The positioning speed measurement is realized through the VLC, so that the problem of electromagnetic compatibility is avoided, the speed measurement error caused by time accumulation is avoided, the influence of low speed is avoided, and the accuracy of the positioning speed measurement is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of trains, and in particular to a vehicle-mounted speed measuring device, a positioning speed measuring method and a train. Background Art

[0002] The train positioning and speed measurement function is an important part of the Communication Based Train Control System (CBTC).

[0003] CBTC is a system that uses a communication network to achieve two-way communication between trains and ground equipment. It controls the safe operation of trains through precise train position information. Existing subway train positioning equipment mainly includes digital audio track circuits, cross-induction loops, query transponders, axle counters, speed sensors, accelerometers, Doppler radars, leaky cables, crack waveguides, etc. Train positioning traditionally uses speed measuring motors or Doppler radars for positioning and speed measurement.

[0004] The speed measurement of the tachometer motor is affected by factors such as wheel diameter error caused by wheel wear, wheel idling, and slipping. The positioning speed measurement error will accumulate over time and become increasingly inaccurate; the Doppler radar test cannot accurately position and measure speed at low speeds.

[0005] In summary, the existing positioning and speed measurement systems are not accurate in positioning and speed measurement. Summary of the invention

[0006] The invention provides a vehicle-mounted speed measuring device, a positioning speed measuring method and a train, which are used to solve the problem of inaccurate positioning speed measurement of trains in the prior art.

[0007] In a first aspect, the present application provides a vehicle-mounted speed measuring device, the device comprising: a processor, a bearing seat, and a light receiving component arranged on a bearing surface of the bearing seat, the light receiving component comprising a photodetector, a light baffle, a lens, and an optical sensor;

[0008] The light blocking plate is provided with M columns of first through holes, the number of the first through holes in each column is the same, and in the row direction, the distance between each column of the first through holes and the carrying surface gradually increases, the row direction is a direction parallel to the carrying surface, the column direction is a direction perpendicular to the carrying surface, and M is a positive integer greater than or equal to 2;

[0009] The lens is located on one side of the light blocking plate;

[0010] The optical sensor is located on a side of the lens away from the light baffle;

[0011] The VLC signal light emitted by the VLC light source passes through the through hole on the light blocking plate and the lens to form a projection on the optical sensor, wherein the VLC light source is installed on the top of the tunnel;

[0012] The photoelectric detector is used to demodulate and decode the received VLC signal light to obtain the emission time;

[0013] The processor is signal-connected to the photodetector and the optical sensor.

[0014] In a possible implementation manner, the first through hole has a first slope relative to the thickness of the light blocking plate.

[0015] In a possible implementation, the light blocking plate is further provided with N columns of second through holes, the number of the second through holes in each column is the same, and on the row square, the distance between each column of the second through holes and the bearing surface gradually decreases, and N is a positive integer greater than or equal to 2;

[0016] In the column direction, the distance between adjacent first through holes is different from the distance between adjacent second through holes; in the row direction, the distance between two adjacent columns of first through holes is different from the distance between two adjacent columns of second through holes; the diameter of the first through hole is the same as the diameter of the second through hole.

[0017] In a possible implementation manner, the second through hole has a second slope relative to the light blocking plate, and the first slope is different from the second slope.

[0018] In a possible implementation manner, the processor is specifically configured to:

[0019] The optical detector is used to demodulate and decode the received VLC signal light to obtain the emission time of the VLC signal light;

[0020] The processor is specifically used for:

[0021] Determining that the train arrives at a first position according to a first projection formed on the optical sensor, and receiving a first emission time of the VLC signal light sent by the optical detector to form the first projection;

[0022] Determine, according to a second projection formed on the optical sensor, that the train arrives at a second position, and receive a second emission time of the VLC signal light sent by the optical detector to form the second projection;

[0023] The travel speed of the train is determined according to the height difference, the preset ratio and the time difference, wherein the time difference is the difference between the second emission time and the first emission time.

[0024] In a possible implementation manner, the processor is specifically configured to:

[0025] Calculating a first ratio of the preset height difference to the preset ratio;

[0026] The ratio of the first ratio to the time difference is used as the running speed of the train.

[0027] In a possible implementation, the preset ratio corresponding to the first through hole is a first preset ratio, and the preset ratio corresponding to the second through hole is a second preset ratio;

[0028] The ratio of the first preset ratio to the distance between two adjacent columns of first through holes is the same as the ratio of the second preset ratio to the distance between two adjacent columns of second through holes.

[0029] In a second aspect, the present application further provides a positioning speed measurement method, which is applied to the vehicle-mounted speed measurement device as described in any one of the first aspects, and the method includes:

[0030] After determining that the train has arrived at a first position according to a first projection formed on the optical sensor, determining a first emission time of the VLC signal light that is received from the optical detector and forms the first projection;

[0031] After determining that the train has arrived at a second position according to a second projection formed on the optical sensor, determining a second emission time of the VLC signal light that is received from the optical detector and forms the second projection;

[0032] The travel speed of the train is determined according to a preset height difference, a preset ratio and a time difference, wherein the time difference is the difference between the second emission time and the first emission time.

[0033] In a possible implementation, determining the travel speed of the train according to the preset height difference, the preset ratio and the time difference includes:

[0034] Calculating a first ratio of the preset height difference to the preset ratio;

[0035] The ratio of the first ratio to the time difference is used as the running speed of the train.

[0036] In a third aspect, the present application also provides a train, comprising an on-board speed measuring device as described in any one of the first aspects.

[0037] The beneficial effects of the present invention are as follows:

[0038] The present application provides a vehicle-mounted speed measuring device, a positioning speed measuring method and a train, wherein the vehicle-mounted speed measuring device includes a processor, a bearing seat and a light receiving component arranged on the bearing surface of the bearing seat, the light receiving component includes a photodetector, a light shield, a lens and an optical sensor, the signal light emitted by the VLC light source passes through the first through hole on the light shield, and then passes through the lens to form a projection on the optical sensor, the processor determines that the train has arrived at the first position and receives the first emission time sent by the photodetector according to the projection, determines that the train has reached the second position and receives the second emission time sent by the photodetector, and determines the travel speed of the train according to the preset height difference, the preset ratio and the time difference, thereby completing the positioning speed measurement, wherein the time difference is the difference between the two emission times. Since the positioning speed measurement is achieved through VLC, there is no electromagnetic compatibility problem, there will be no speed measurement error caused by the accumulation of time, and it will not be affected by low speed, thereby improving the accuracy of positioning speed measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0040] Figure 1 A schematic diagram of an application scenario of positioning and speed measurement provided in an embodiment of the present application;

[0041] Figure 2 A schematic diagram of the structure of a vehicle-mounted speed measuring device is provided for an embodiment of the present application;

[0042] Figure 3 A front schematic diagram of a light blocking plate provided in an embodiment of the present application;

[0043] Figure 4 A side cross-sectional view of a light barrier provided in an embodiment of the present application;

[0044] Figure 5 A schematic diagram of another application scenario of positioning and speed measurement provided in an embodiment of the present application;

[0045] Figure 6 A side cross-sectional view of another light barrier provided in an embodiment of the present application;

[0046] Figure 7 A schematic diagram of another application scenario of positioning and speed measurement provided in an embodiment of the present application;

[0047] Figure 8 A schematic diagram of another application scenario of positioning and speed measurement provided in an embodiment of the present application;

[0048] Fig. 9 A front schematic diagram of another light-blocking plate provided in an embodiment of the present application;

[0049] Fig.10 A side cross-sectional view of another light barrier provided in an embodiment of the present application;

[0050] Fig.11 A schematic diagram of another application scenario of positioning and speed measurement provided in an embodiment of the present application;

[0051] Fig.12 A schematic diagram of another application scenario of positioning and speed measurement provided in an embodiment of the present application;

[0052] Fig.13 A schematic diagram of another application scenario of positioning and speed measurement provided in an embodiment of the present application;

[0053] Fig.14 A schematic flow chart of a method for positioning and speed measurement provided in an embodiment of the present application. DETAILED DESCRIPTION

[0054] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this application.

[0055] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the feature. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0056] At present, trains rely on the absolute position of speed measuring motors, Doppler radars and trackside transponders to perform positioning and speed measurement. However, the speed measurement of speed measuring motors is affected by factors such as wheel diameter error caused by wheel wear, wheel idling, and slipping, and the distance measurement error accumulates over time. Moreover, in actual use, the installation process of speed measuring motors and radars is very demanding, and it is easy to have inaccurate positioning due to insufficient installation accuracy. The trackside transponders laid at fixed positions on the line can correct the position of the train, but the price of a single trackside transponder is high, and it is not economically feasible to install a large number of short-distance trains; and for trains using linear motors, the on-board transponder that communicates with the trackside transponder may not work due to electromagnetic compatibility issues, causing the train position correction to fail. In addition, the inability to accurately re-position after a large-scale or long-term system failure is also a limitation of this system. Therefore, the existing positioning and speed measurement system is prone to the problem of inaccurate positioning, resulting in inaccurate positioning and speed measurement.

[0057] Triangulation distance measurement is a commonly used distance measurement principle in the automation industry. For example, a laser distance meter based on the triangulation distance measurement principle measures the distance between workpieces. This distance measurement method has high measurement accuracy (affected by grating density) within a short distance and can measure continuously. VLC (Visible Light Communication) is a communication technology that uses VLC light source as a signal source and visible light waves as a communication carrier to directly transmit optical signals in the air. That is, a point light source based on VLC technology can send information such as its own position and the time when the light signal is sent into space. After the photoelectric detector receives the VLC signal light, it demodulates and decodes the VLC signal light to obtain the position of the VLC light source and the emission time of the VLC signal light.

[0058] The embodiment of the present application is based on the principle of optical triangulation distance measurement, such as Figure 1 As shown, a VLC light source 11 capable of emitting VLC signals is installed on the top of the tunnel, and the signal contains the position information of the VLC light source and the emission time of the VLC signal light. An on-board speed measuring device 12 is installed on the top of the train, wherein the bearing seat in the on-board speed measuring device 12 is parallel to the vehicle body, and the light blocking plate in the on-board speed measuring device 12 is vertically arranged with the bearing seat. At the same time, a lens and an optical sensor are sequentially arranged in the direction of the light blocking plate away from the incident direction of the light signal, and M columns of first through holes are arranged on the light blocking plate, and the number of the first through holes in each column is the same. In the row direction, the distance between each column of the first through holes and the bearing surface of the bearing seat gradually increases.

[0059] During the running of the train, the VLC signal light emitted by the VLC light source 11 located at the top of the tunnel passes through the first through hole on the light blocking plate, and then passes through the lens to form a first projection on the optical sensor. The processor determines that the train has reached the first position based on the first projection formed on the optical sensor, and the processor receives the first emission time sent by the photodetector; the train continues to run, and the VLC signal light emitted by the VLC light source 11 passes through the first through hole on the light blocking plate, and then passes through the lens to form a second projection on the optical sensor. The processor determines that the train has reached the second position based on the second projection formed on the optical sensor, and the processor receives the second emission time sent by the photodetector; the processor determines the running speed of the train between the first position and the second position based on the preset height difference, the preset ratio and the time difference, wherein the time difference is the time difference between the first emission time and the second emission time.

[0060] The embodiments of the present application do not require complex image processing calculations, and VLC and laser micro-hole drilling technologies are currently very mature. Visible light band signal transmission / reception does not have electromagnetic compatibility problems, and there are serious multi-path reflection problems of electromagnetic waves in narrow spaces. It has no effect on the operation of key communication equipment on trains and in tunnels. The positioning and speed measurement accuracy is high and the error does not accumulate, especially at low speeds.

[0061] like Figure 2 As shown, it is a schematic diagram of the structure of a vehicle-mounted speed measuring device provided in an embodiment of the present application, and the vehicle-mounted speed measuring device includes: a processor ( Figure 2 ), a bearing seat 21 and a light receiving component 22 disposed on the bearing surface of the bearing seat 21, the light receiving component 22 includes a photodetector ( Figure 2 ), a light baffle 221, a lens 223 and an optical sensor 224;

[0062] like Figure 3 As shown, the light blocking plate 221 is provided with M columns of first through holes, the number of the first through holes in each column is the same, and in the row direction, the distance between the first through holes in each column and the bearing surface gradually increases, the row direction is a direction parallel to the bearing surface, the column direction is a direction perpendicular to the bearing surface, and M is a positive integer greater than or equal to 2;

[0063] A lens 222 is located on one side of the light blocking plate 221;

[0064] The optical sensor 223 is located on a side of the lens 222 away from the light baffle 221;

[0065] After the signal light emitted by the VLC light source passes through the first through hole on the light blocking plate 221, it passes through the lens 222 and forms a projection on the optical sensor 223, wherein the VLC light source is installed on the top of the tunnel;

[0066] The photoelectric detector is used to demodulate and decode the received VLC signal light to obtain the emission time processor, and is connected to the optical sensor 223 signal.

[0067] In the embodiment of the present application, the VLC signal light emitted by the VLC light source forms a projection on the optical sensor 223 through the lens 222 after passing through the first through hole on the light baffle 221. The processor determines that the train has arrived at the first position and receives the first emission time sent by the photodetector based on the projection. The processor determines that the train has reached the second position and receives the second emission time sent by the photodetector based on the projection, and determines the travel speed of the train based on the preset height difference, preset ratio and time difference, thereby completing the positioning and speed measurement, wherein the time difference is the time difference between the two emission times. Since positioning and speed measurement are achieved through VLC, there is no electromagnetic compatibility problem, no speed measurement error caused by the accumulation of time, and no influence of low speed, thereby improving the accuracy of positioning and speed measurement.

[0068] It should be noted that, in the embodiment of the present application, the photoelectric detector can be arranged on the supporting base 21, and the specific position is not limited, as long as it can receive the VLC signal light emitted by the VLC light source.

[0069] like Figure 3 As shown, the embodiment of the present application is described with M=4, and each column includes 3 first through holes. In a specific implementation, the light baffle 221 can be vertically installed on the top of the train. The thickness of the light baffle 221 can be 1 cm, and the diameter of the first through hole can be 0.1 mm. For each column of first through holes, the distance d3 between adjacent first through holes can be 0.5 mm. For two adjacent columns of first through holes, the distance d1 between two adjacent columns of first through holes can be 0.5 mm. The distance between the first through holes in the latter column and the bearing surface can be 0.05 mm, that is, d2=0.05 mm. The light baffle 221 can be a plastic plate, and a lens 222 and an optical sensor 223 are installed behind the plastic plate. When the train is running, the signal light emitted by the VLC light source can pass through part of the first through holes, thereby forming a projection on the optical sensor.

[0070] like Figure 4 As shown, the thickness d4 of the light blocking plate 221 can be 1 cm, and the diameter of the first through hole 2211 is 0.1 mm. When there is no slope between the first through hole and the light blocking plate 221, the preset ratio is the diameter of the first through hole 2211: the thickness d4 of the light blocking plate 221 = 1:100.

[0071] When the horizontal distance between the train and the VLC light source is L, the first through hole above a specific height H on the plastic plate can pass the light, for example Figure 5As shown, when the train travels to the first position S1, the horizontal distance between the train and the VLC light source is the first distance L1, and the first through hole on the plastic plate above the height H1 can pass the light. When the train travels to the second position S2, the horizontal distance between the train and the VLC light source is the second distance L2, and the first through hole on the plastic plate above the height H2 can pass the light. After the optical sensor 223 sends the first projection and the second projection to the processor, the processor can obtain the height change H1-H2, that is, the height difference, according to the first projection formed by the train at the first position S1 and the second projection formed by the train at the second position S2. The processor can also receive the first emission time T1 corresponding to the first projection sent by the photoelectric detector. and the second emission time T2 corresponding to the second projection, after obtaining the first emission time T1 and the second emission time T2, the time difference T2-T1 is determined, and the processor obtains (L2-L1) / (H2-H1)=1:100 according to the principle of triangulation, wherein 1:100 is a preset ratio, i.e., the ratio of the diameter of the first through hole to the thickness of the light baffle 223, the width of the light baffle 223 is 1 cm, and the diameter of the first through hole is 0.1 mm, then the ratio of the diameter of the first through hole to the width of the light baffle 223 is 1:100, therefore, the speed of the train V=(H2-H1)*(1:100) / (T2-T1), i.e., V is the average speed of the train between the first position S1 and the second position S2.

[0072] It should be noted that, in the embodiment of the present application, the light passing through the first through hole is the signal light having a brightness greater than or equal to a preset threshold in the projection.

[0073] The embodiment of the present application calculates the distance between the train and the VLC light source based on the principle of triangulation distance measurement. While measuring the distance, the relative / absolute position of the VLC light source itself is also obtained, so the position of the train relative to the VLC light source is calculated.

[0074] It should be noted that in the embodiment of the present application, the photoelectric detector analyzes the VLC signal light, and in addition to obtaining the emission time of the VLC signal light, the position information of the VLC light source can also be obtained. The position information may include a three-dimensional absolute position and a relative position along the tunnel direction. The three-dimensional absolute position may include longitude, latitude and altitude. The relative position along the tunnel direction can divide the subway line into several sections. If the VLC light source is located in section a and the distance from the starting point of section a is b, the relative position can be expressed as (a, b). In the embodiment of the present application, the relative position along the tunnel direction can be used for ranging and positioning.

[0075] In a specific implementation, a VLC light source that can emit VLC signals is installed on the top of the tunnel. The VLC signal may include the position of the VLC light source (absolute position or relative position to the track), time information, vertical distance from the rail, track slope, self-identification code, etc.

[0076] A light receiving assembly is installed at the head of the train. The light receiving assembly includes a photodetector, a light baffle, a lens and an optical sensor. In addition to the light receiving assembly, the on-board speed measuring equipment also includes a processor and a data transmission line.

[0077] The light baffle 221 is vertically installed on the head of the train, with a thickness of 1 cm and a diameter of the first through hole of 0.1 mm; the center distance between two adjacent first through holes in the vertical direction is 0.5 mm; the center distance between two adjacent first through holes in the horizontal direction is 0.5 mm, and the center of the first through hole on the right is 0.05 mm higher than the center of the first through hole on the left; in a specific implementation, the width of the light baffle 221 is set to be greater than 5 mm to ensure that there are 10 columns of first through holes in the horizontal direction; the height of the light baffle 221 is set to be greater than 10 cm to ensure that there are more than 2000 rows of first through holes, ensuring that the effective ranging range is greater than 10 meters.

[0078] In a specific implementation, the VLC light source should not be too high above the light shielding plate 221 at the head of the train, otherwise when the train and the VLC light source are close, the signal light emitted by the VLC light source cannot pass through the first through hole on the light shielding plate, resulting in failure to locate and measure speed. For example, if the VLC light source is 1 cm higher than the first through hole at the top of the light shielding plate, the light can pass through the first through hole on the light shielding plate at a horizontal distance of 1 meter or more, but the light cannot pass through the light shielding plate within a horizontal distance of 1 meter.

[0079] like Figure 5 As shown, there are two positions S1 and S2 at a horizontal distance of 1 meter from the VLC light source. At the first emission time T1, the train moves to the first position S1, the horizontal distance between the first position S1 and the VLC light source is L1, and the height of the first through hole where the light intensity through the first through hole is higher than a specific threshold from the upper edge of the light blocking plate is H1; at the second emission time T2, the train moves to the second position S2, the horizontal distance between the second position S2 and the VLC light source is L2, and the height of the first through hole where the light intensity through the first through hole is higher than a specific threshold from the upper edge of the light blocking plate is H2. Since (H1-H2):(L1-L2)=1:100, assuming H1-H2=0.05mm, then L1-L2=5mm, the train moves 5mm in the time period T2-T1, and the speed measurement is completed while measuring the distance change.

[0080] Assuming that the distance L1 between the above-mentioned first position S1 and the VLC light source is 10 meters, and the first position S1 is set as the reference position, the first through hole at the height H1 on the light blocking plate can be used as the reference ranging starting point, and the position information of the VLC light source obtained by analyzing the VLC signal light can be used to continuously measure the distance (resolution is 5mm), position and speed within a horizontal distance of 10 meters to 1 meter from the VLC light source.

[0081] After the photoelectric detector receives the VLC signal light, it demodulates and decodes the VLC signal light to obtain the emission time. The photoelectric detector sends the emission time obtained by demodulation and decoding to the processor. The processor completes the positioning and speed measurement based on the received projection and emission time. In order to make the information obtained by demodulation and decoding more accurate, the received VLC signal can be first anti-shake processed. The specific anti-shake processing method can adopt the method provided in the relevant technology, which will not be repeated here.

[0082] The processor can analyze the distribution of projected light intensity to obtain changes in light height, that is, analyze the projection formed on the optical sensor. Therefore, there is no need for additional image processing and floating-point and matrix operations, which improves computing efficiency.

[0083] In the positioning and speed measurement method in the above embodiment, there may be a situation where light cannot pass through any first through hole within a certain distance, and at this time, the distance cannot be measured; the relative installation height accuracy requirement of the VLC light source and the light shield is relatively high, and the preset ratio is 1:100. Then, a relative height error of 1mm will cause a reference distance measurement starting point position error of 100mm; therefore, the first through hole can be set to have a first slope relative to the thickness of the light shield, such as Figure 6 As shown, the first slope a1 is d5 / d4.

[0084] When the first through hole has a first slope, such as Figure 7 As shown, the displacement between two moments can still be calculated using the formula (H1-H2):(L1-L2)=1:100.

[0085] In one embodiment, if the VLC light sources are continuously arranged in the tunnel, for example, one VLC light source is installed every 10 meters, then the light from the multiple VLC light sources can pass through the first through hole on the light baffle, which may make it impossible to accurately calculate the change in the height of the light passing through the first through hole on the light baffle. Figure 8 As shown, in order to solve this problem, a sunshade at a certain angle can be installed for each VLC light source, but a very high installation accuracy is required. Based on this problem, an embodiment of the present application provides the following vehicle-mounted speed measuring device, which is described in detail below.

[0086] like Fig. 9 As shown, the light blocking plate 221 is further provided with N columns of second through holes 2222, the number of the second through holes in each column is the same, and in the row direction, the distance between each column of the second through holes 2222 and the bearing surface gradually decreases, and N is a positive integer greater than or equal to 2;

[0087] In the column direction, the distance between adjacent first through holes 2221 is different from the distance between adjacent second through holes 2222; in the row direction, the distance between two adjacent columns of first through holes 2221 is different from the distance between two adjacent columns of second through holes 2222; the diameter of the first through hole 2221 is the same as the diameter of the second through hole 2222.

[0088] In the embodiment of the present application, in the column direction, the distance between adjacent first through holes 2221 is different from the distance between adjacent second through holes 2222; in the row direction, the distance between two adjacent columns of first through holes 2221 is different from the distance between two adjacent columns of second through holes 2222; the diameter of the first through hole 2221 is the same as the diameter of the second through hole 2222. Therefore, the first through hole 2221 and the second through hole 2222 can pass through the VLC light source located at two different positions respectively, thereby making the positioning and speed measurement more accurate.

[0089] For example, the width of the light shielding plate 221 is more than 10 mm, ensuring that there are 20 columns of through holes (including first through holes and second through holes) in the horizontal direction; the distribution of the 10 columns of first through holes on the left side remains unchanged; the center spacing of the two vertically adjacent second through holes in the 10 columns of second through holes on the right side is set to 0.4 mm; the center spacing of the two horizontally adjacent second through holes is 0.4 mm, and the center of the second through hole on the right side is 0.04 mm lower than the center of the second through hole on the left side; the 10 columns of through holes on the left and right sides have a certain slope in the vertical direction of the light shielding plate, and the slopes are different, such as Figure 6 As shown, the first slope of the first through hole is a1, such as Fig.10 As shown, the second slope of the second through hole is a2.

[0090] like Fig.11As shown, at time T1, the train advances to position 1, the horizontal distance between position 1 and the VLC light source is L1, and the optical sensor detects that the light intensity passing through a specific first through hole in the 10 columns on the left is lower than a specific threshold value (i.e., it is considered that no light passes through); at time T2, the train advances to position 2, the horizontal distance between position 2 and the VLC light source is L2, and the optical sensor detects that the light intensity passing through a specific first through hole in the 10 columns on the left is higher than a specific threshold value (i.e., it is considered that light passes through), and the height of the specific first through hole from the upper edge of the light shield is H1; at time T3, the train advances to position 3 , the horizontal distance between position 3 and the VLC light source is L3, and the optical sensor detects that the light intensity passing through the first through hole on the right side horizontally adjacent to the specific first through hole, or the first through hole on the left side of the row above is higher than a specific threshold value, and the height of the first through hole on the right side horizontally adjacent to the specific first through hole or the first through hole on the left side of the row above the specific first through hole is H2 from the upper edge of the light blocking plate; then H2-H1=0.05mm, and since (H2-H1):(L2-L3)=1:100, so L2-L3=5mm, the train moves forward 5mm in the time period T3-T2, and the measurement is completed while measuring the distance change.

[0091] Similarly, for the second through holes in the 10 columns on the right, repeat the above process, then H2-H1=0.04mm, and because (H2-H1):(L2-L3)=1:125, therefore L2-L3=5mm, the train moves forward 5mm in the time period T3-T2, and the measurement is completed while measuring the distance change.

[0092] In an embodiment of the present application, if a first through hole and a second through hole are provided on the light blocking plate, and both the first through hole and the second through hole have a slope, then in order to make the resolution the same, the ratio of the first preset ratio to the distance between two adjacent columns of the first through holes and the ratio of the second preset ratio to the distance between two adjacent columns of the second through holes are the same.

[0093] For example, the distance between two adjacent rows of first through holes is 0.5 mm, and the distance between two adjacent rows of second through holes is 0.4 mm. The first preset ratio may be 1:100, and the second preset ratio may be 1:125, that is, 0.5 / (1:100)=0.4 / (1:125).

[0094] The through holes on the left and right sides have slopes. When the VLC light sources are continuously arranged in the tunnel, by adjusting the installation distance, it can be ensured that only the light from the nearest VLC light source can pass through the through holes.

[0095] If at a certain position horizontally away from the VLC light source L, the light intensity through the first through hole on the left side is higher than a specific threshold (i.e., it is considered that light has passed through), the lower edge height of the microhole is H1, and the light intensity through the second through hole on the right side is higher than a specific threshold (i.e., it is considered that light has passed through), the lower edge height of the microhole is H2, such as Fig.12 As shown, H2>H1, height difference H-H1=Hd, Hd is proportional to the horizontal distance of the VLC light source, and has nothing to do with the relative installation height of the VLC light source and the plastic light shield, so there is no need to strictly require the relative installation height of the VLC light source and the light shield, that is, when Hd is a certain value, the distance between the light shield and the VLC light source is also a certain value, which is used as the reference position, and H1 and H2 at this position are the reference distance measurement starting points of the left and right micro-holes respectively. After determining the reference distance measurement starting points of the left and right micro-holes, continuous height measurement / distance measurement can be performed synchronously, and the distance measurement resolution is 5mm. In order to improve the accuracy of height measurement / distance measurement, the height measurement / distance measurement results of the two parts can be averaged or necessary filtering can be performed.

[0096] For the case where the distance cannot be measured within a certain distance, the above analysis shows that after determining the reference distance measurement starting point of the through holes on the left and right parts, the height of the through holes through which the light can pass gradually increases during the process of the train approaching the VLC light source. Therefore, a light shielding plate with a higher height can be used, and the first preset ratio corresponding to the first through hole, the second preset ratio corresponding to the second through hole, and the installation distance of adjacent VLC light sources can be adjusted, so that when the through hole through which the light of the near-end VLC light source passes approaches the upper edge of the light shielding plate, the light of the far-end VLC light source can pass through the through hole in the lower part of the light shielding plate and complete the distance measurement and positioning ( Fig.13 As shown in the figure, it is possible to realize continuous and uninterrupted positioning and speed measurement of trains in the track section where VLC is continuously laid out.

[0097] In specific implementations, light shielding plates with other corresponding thicknesses, micropore diameters, and slopes can be selected according to actual needs.

[0098] Based on the same inventive concept, the embodiment of the present application also provides a positioning and speed measurement method. The implementation of the method can refer to the implementation of the device, and the repeated parts will not be repeated.

[0099] like Fig.14 FIG. 1 is a flow chart of a positioning and speed measurement method provided in an embodiment of the present application, which specifically includes the following steps:

[0100] S1301, after determining that the train has arrived at a first position according to a first projection formed on the optical sensor, determine a first emission time of the VLC signal light that is received from the optical detector and forms the first projection;

[0101] S1302, after determining that the train has arrived at a second position according to a second projection formed on the optical sensor, determining a second emission time of the VLC signal light that is received from the optical detector and forms the second projection;

[0102] S1303. Determine the travel speed of the train according to a preset height difference, a preset ratio and a time difference, wherein the time difference is the difference between the second emission time and the first emission time.

[0103] In one embodiment, determining the travel speed of the train according to the preset height difference, the preset ratio and the time difference includes:

[0104] Calculating a first ratio of the preset height difference to the preset ratio;

[0105] The ratio of the first ratio to the time difference is used as the running speed of the train.

[0106] Based on the same inventive concept, an embodiment of the present application also provides a train. The implementation of the train can refer to the implementation of the equipment, and the repeated parts will not be repeated.

[0107] The train provided in the embodiments of the present application includes the on-board speed measuring device described in any one of the above embodiments.

[0108] The present application is described above with reference to the block diagrams and / or flow charts showing the methods, devices (systems) and / or computer program products according to the embodiments of the present application. It should be understood that a block of the block diagram and / or flow chart diagram and a combination of blocks of the block diagram and / or flow chart diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer and / or other programmable data processing device to produce a machine, so that the instructions executed by the computer processor and / or other programmable data processing device create a method for implementing the functions / actions specified in the block diagram and / or flow chart block.

[0109] Accordingly, the present application may also be implemented with hardware and / or software (including firmware, resident software, microcode, etc.). Furthermore, the present application may take the form of a computer program product on a computer-usable or computer-readable storage medium, which has a computer-usable or computer-readable program code implemented in the medium, for use by an instruction execution system or in conjunction with an instruction execution system. In the context of the present application, a computer-usable or computer-readable medium may be any medium that may contain, store, communicate, transmit, or convey a program for use by an instruction execution system, device, or apparatus, or in conjunction with an instruction execution system, device, or apparatus.

[0110] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A vehicle-mounted speed measuring device, characterized in that: The device comprises: a processor, a bearing seat and a light receiving component arranged on the bearing surface of the bearing seat, wherein the light receiving component comprises a photoelectric detector, a light blocking plate, a lens and an optical sensor; The light blocking plate is provided with M columns of first through holes, the number of the first through holes in each column is the same, and in the row direction, the distance between each column of the first through holes and the carrying surface gradually increases, the row direction is a direction parallel to the carrying surface, the column direction is a direction perpendicular to the carrying surface, and M is a positive integer greater than or equal to 2; The lens is located on one side of the light blocking plate; The optical sensor is located on a side of the lens away from the light baffle; The VLC signal light emitted by the VLC light source passes through the through hole on the light blocking plate and the lens to form a projection on the optical sensor, wherein the VLC light source is installed on the top of the tunnel; The photoelectric detector is used to demodulate and decode the received VLC signal light to obtain the emission time; The processor is signal-connected to the photodetector and the optical sensor.

2. The device according to claim 1, characterized in that The first through hole has a first slope relative to the thickness of the light blocking plate.

3. The device according to claim 2, characterized in that The light blocking plate is further provided with N columns of second through holes, the number of the second through holes in each column is the same, and in the row direction, the distance between each column of the second through holes and the bearing surface gradually decreases, and N is a positive integer greater than or equal to 2; In the column direction, the distance between adjacent first through holes is different from the distance between adjacent second through holes; in the row direction, the distance between two adjacent columns of first through holes is different from the distance between two adjacent columns of second through holes; the diameter of the first through hole is the same as the diameter of the second through hole.

4. The device according to claim 3, characterized in that The second through hole has a second slope relative to the light blocking plate, and the first slope is different from the second slope.

5. The device according to claim 1, characterized in that The optical detector is used to demodulate and decode the received VLC signal light to obtain the emission time of the VLC signal light; The processor is specifically used for: Determining that the train arrives at a first position according to a first projection formed on the optical sensor, and receiving a first emission time of the VLC signal light sent by the optical detector to form the first projection; Determine, according to a second projection formed on the optical sensor, that the train arrives at a second position, and receive a second emission time of the VLC signal light sent by the optical detector to form the second projection; The travel speed of the train is determined according to the height difference, the preset ratio and the time difference, wherein the time difference is the difference between the second emission time and the first emission time.

6. The device according to claim 5, characterized in that The processor is specifically used for: Calculating a first ratio of the preset height difference to the preset ratio; The ratio of the first ratio to the time difference is used as the running speed of the train.

7. The device according to claim 5, characterized in that The preset ratio corresponding to the first through hole is a first preset ratio, and the preset ratio corresponding to the second through hole is a second preset ratio; The ratio of the first preset ratio to the distance between two adjacent columns of first through holes is the same as the ratio of the second preset ratio to the distance between two adjacent columns of second through holes.

8. A positioning speed measurement method, characterized in that: Applied to the vehicle-mounted speed measuring device according to any one of claims 1 to 7, the method comprises: After determining that the train has arrived at a first position according to a first projection formed on the optical sensor, determining a first emission time of the VLC signal light that is received from the optical detector and forms the first projection; After determining that the train has arrived at a second position according to a second projection formed on the optical sensor, determining a second emission time of the VLC signal light that is received from the optical detector and forms the second projection; The travel speed of the train is determined according to a preset height difference, a preset ratio and a time difference, wherein the time difference is the difference between the second emission time and the first emission time.

9. The method according to claim 8, characterized in that The step of determining the travel speed of the train according to the preset height difference, the preset ratio and the time difference comprises: Calculating a first ratio of the preset height difference to the preset ratio; The ratio of the first ratio to the time difference is used as the running speed of the train.

10. A train, characterized in that: It comprises the vehicle-mounted speed measuring device as described in any one of claims 1 to 7.

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