Passive laser kilometer post

Abstract

The invention discloses a passive laser kilometer post which is used in cooperation with a vehicle-mounted laser positioning terminal. The vehicle-mounted laser positioning terminal is mounted on a rail transit vehicle; and the plurality of passive laser kilometer posts are distributed and mounted on the ground along the running track of the track traffic vehicle at an interval of 1km in pairs. The passive laser kilometer posts are composed of corner reflectors and reflected light modulation sheets, the corner reflectors and the reflected light modulation sheets are arranged according to the characteristics of wavelengths and the like of light allowed to pass through by the reflected light modulation sheets, a certain rule is strictly followed, and the wavelengths of the light allowed to pass through by the reflected light modulation sheets on any two passive laser kilometer posts arranged in a cycle are different. The laser signal emitted by the vehicle-mounted terminal is reflected as the kilometer post signal, a power supply is not needed, and the intensity of the reflected signal is not influenced by the environment. The light modulation sheet in front of the corner reflector modulates the same laser signal emitted by the vehicle-mounted laser positioning terminal into laser signals with different wavelengths, different information can be fed back at different positions, and positioning errors under special conditions are avoided.

Description

Technical Field

[0001] The present invention relates to the field of positioning technology, and in particular to the field of rail transit laser precise positioning technology. Background Art

[0002] Traditional kilometer markers are set at every full kilometer or half kilometer of a line from the starting point. Their main function is to accurately indicate the location of the line, but they cannot directly and accurately locate the train. At present, satellite positioning and ordinary active kilometer markers that can locate trains also have some unhandled situations. For example, satellite positioning is only performed once every 5-10 seconds, and the train travels very fast. 5 seconds often travels a long distance. If an accident occurs during this period, it is very dangerous not to get timely positioning. If the train enters a tunnel, the satellite has almost no signal and cannot obtain the position of the train in the tunnel, which is also very dangerous. Ordinary active kilometer markers themselves require power, and when there is interference or power failure somewhere, one kilometer of positioning will be lost, resulting in inaccurate positioning. In general, the kilometer markers in the rail transit industry are currently only satisfactory, and innovative ideas are needed to break the deadlock. Summary of the invention

[0003] Purpose: To overcome the problems that traditional kilometer markers cannot accurately locate trains, satellite positioning cannot achieve real-time positioning, there is no signal in tunnels, and ordinary active beacons require power and cannot be automatically corrected, the present invention provides a passive laser kilometer marker. This passive laser kilometer marker can not only utilize the reflection modulation characteristics of light, but also utilize the time difference of reflected light to achieve millisecond-level real-time positioning and speed measurement accurate to meters, and can be used in tunnels. At the same time, it utilizes the wavelength, frequency and other characteristics of light to achieve automatic correction and positioning. It does not require any energy and achieves the above functions completely through the reflection of light.

[0004] Technical solution: The passive laser kilometer marker consists of a corner reflector and a laser reflection light modulator. A laser reflection light modulator is installed in front of the corner reflector. The corner reflector reflects the laser emitted from the on-board positioning terminal on the train as a signal back to the on-board terminal. The reflection light modulator modulates the same laser signal emitted by the on-board terminal into laser signals of different wavelengths, phases, etc.

[0005] Beneficial effects: Passive laser kilometer markers do not require power, and the laser signal reflected from the train's onboard terminal is returned to the onboard positioning terminal as a signal along the original path. The distance between the train and the passive laser kilometer marker is calculated by the time difference and speed of light between the laser emitted by the onboard positioning terminal on the train and the laser reflected back from the passive laser kilometer marker, thereby achieving meter-level positioning of the train. The train speed is calculated by the displacement and interval time between each two positioning. Since the laser speed measurement has a fast response, the single speed measurement time is about 0.06 seconds, and the speed of high-speed running trains can be measured with an error of only ±0.1km / h. Correction is achieved by distinguishing adjacent passive laser kilometer markers through the different wavelengths that the reflected light modulator can pass, and the reflected light modulators that can pass lasers of different wavelengths are installed in a regular arrangement to avoid the situation where leakage accumulation and inaccurate positioning occur after a certain kilometer marker fails. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 This is a schematic diagram of the positioning principle of the ground terminal and the vehicle terminal. The numbers in the figure are: 1. A passive laser kilometer marker, such as Figure 2 As shown; 2. Vehicle positioning terminal, such as Figure 5 shown.

[0007] Figure 2 A schematic diagram of a passive laser kilometer marker. The numbers in the figure are: I, front view; II, left view; 1. A corner reflector, such as Figure 3 2. A reflective light modulator, such as Figure 4 shown.

[0008] Figure 3 This is a schematic diagram of the principle of a corner reflector. The incident light is reflected from different mirrors at least once and at most three times and then returns to its original path.

[0009] Figure 4 This is a schematic diagram of the principle of a reflective light modulator. The numbers in the figure are: 1, glass; 2, coating layer. When the laser irradiates the coating layer 2, only the light with a wavelength within a certain range can pass through the coating layer 2 to the glass 1 and pass through the glass 1, and the light with a wavelength outside the range is completely diffusely reflected.

[0010] Figure 5 It is a vehicle-mounted laser positioning terminal. The numbers in the figure are: I, main view; II, left view; 1, laser receiving window; 2, laser emitting window.

[0011] Figure 6 This is a schematic diagram of the principle of a vehicle-mounted laser positioning terminal. Specific implementation methods

[0012] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in combination with specific examples and with reference to the accompanying drawings.

[0013] A passive laser kilometer marker, such as Figure 1 As shown in the ground terminal 1, it includes multiple passive laser kilometer markers 1 and a vehicle-mounted laser positioning terminal 2. The vehicle-mounted laser positioning terminal 2 is installed on the rail transit vehicle. Multiple passive laser kilometer markers 1 are installed on the ground along the rail transit vehicle with a distance of 1 km between them. They are arranged according to the wavelength of light allowed to pass through the reflected light modulator on the passive laser kilometer marker 1, strictly following a certain rule, and the wavelength of light allowed to pass through the reflected light modulator on any two passive laser kilometer markers 1 within one cycle of arrangement cannot be the same.

[0014] The passive laser kilometer marker 1 and the vehicle-mounted laser positioning terminal 2 are wirelessly positioned accurately by laser, and the vehicle-mounted laser positioning terminal 2 has a laser transceiver function. In the present invention, the passive laser kilometer marker 1 is composed of a corner reflector and a reflected light modulator.

[0015] Passive laser kilometer marker Figure 2 As shown, it includes a corner reflector 1 and a reflection light modulator 2. The reflection light modulator 2 and the outer shell surround the corner reflector 1, and unmodulated laser signals are not allowed to directly reach the corner reflector 1. The laser emitted to the passive laser kilometer mark must first pass through the reflection light modulator 2. Only laser signals with a specific wavelength can pass through the reflection light modulator 2 to reach the corner reflector 1, and laser signals that deviate from this wavelength are dispersed and reflected in all directions. After the laser signal with a specific wavelength reaches the corner reflector 1, it is reflected at least 1 time and at most 3 times, and then returns to the on-board laser positioning terminal 2 as a new laser signal in the same path and opposite direction. The on-board laser positioning terminal 2 processes the received laser signal to calculate the real-time position and speed of the train.

[0016] Corner reflectors 1 are used to achieve passivity by reflecting laser signals.

[0017] The role of the reflected light modulator 2 is to modulate the same laser signal emitted by the vehicle-mounted laser positioning terminal 2 into different laser signals. After receiving different laser signals, the vehicle-mounted laser positioning terminal 2 has different judgment and calculation formulas instead of simply accumulating.

[0018] Vehicle-mounted laser positioning terminal Figure 5 As shown in FIG. 1 , there is a laser receiving window 1 and a laser emitting window 2. Figure 6As shown, it includes a precise positioning speed measurement module, a timing module 1, a wavelength timing module 1, a laser driving module, a laser, a light detector, a signal processing module, a light wave timing module 2, and a timing module 2. The input end of the timing module 1 is connected to the precise positioning module, the output end of the timing module 1 is connected to the input end of the laser driving module via the wavelength encoding module, and the output end of the laser driving module is connected to the input end of the laser. The output end of the light detector is connected to the input end of the light wave decoding module via the signal processing module, the output end of the light wave decoding module is connected to the input end of the timing module 2, and the output end of the timing module 2 is connected to the precise positioning module.

[0019] The present invention utilizes wireless laser for precise positioning and ranging to avoid the situation where there is no satellite signal in the tunnel; utilizes a corner reflector to reflect laser signals to avoid the situation where the traditional kilometer marker cannot work when there is no power or power failure; utilizes a reflected light modulator to convert the same laser signal into a laser signal of a specific wavelength to realize the selection of a calculation formula, thereby avoiding the situation where positioning errors occur when a kilometer marker fails to work normally.

[0020] It should be noted that although the embodiments of the present invention described above are illustrative, they are not intended to limit the present invention, and therefore the present invention is not limited to the above specific embodiments. Without departing from the principles of the present invention, any other embodiments obtained by those skilled in the art under the guidance of the present invention are deemed to be within the protection of the present invention.

Claims

1. A passive laser kilometer marker, characterized in that: The reflected light modulator and the housing surround the corner reflector and are installed on the trackside; the on-board wireless positioning terminal has the function of laser transceiver and is installed on the head of the train. After emitting the laser to the passive laser kilometer mark on the trackside, the passive laser kilometer mark will reflect the modulated laser back and be received by the on-board wireless positioning terminal.

2. A passive laser kilometer marker according to claim 1, characterized in that: Wireless laser precise positioning is used to transmit and receive signals between passive laser kilometer markers and trains, so that trains will not lose their position in tunnels.

3. A passive laser kilometer marker according to claim 1, characterized in that: The laser signal emitted by the train is transmitted by a corner reflector as a signal emitted by a passive laser kilometer marker and can be used passively.

4. The passive laser kilometer marker according to claim 1 is characterized in that: The same laser signal emitted by the train is modulated into a laser signal of a specific wavelength using a reflected light modulator.

5. The passive laser kilometer marker according to claim 1 is characterized in that: Multiple passive laser kilometer markers are installed on the ground along the rail transit track with a spacing of 1 km between them. They are arranged according to the wavelength of light allowed to pass by the reflected light modulator on the passive laser kilometer markers, strictly following a certain rule, and the wavelength of light allowed to pass by the reflected light modulator on any two passive laser kilometer markers within one cycle of arrangement cannot be the same.

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