A method and system for target location using passive optical pulse signals

Abstract

The present application relates to a kind of methods for target positioning, to solve the problem that target cannot be positioned by passive receiving target emission light source at present.The present application proposes a kind of methods and systems for target positioning using passive optical pulse signal, comprising the following steps, S1, establish the target positioning system of receiving optical pulse signal;S2, construct the right-angle coordinate system built by several photoelectric sensors and positioning target;S3, the phase difference of the periodic optical pulse signal received by different photoelectric sensors is calculated by phase calculation module;S4, the specific coordinate of target W in the right-angle coordinate system is calculated by position coordinate calculation module;S5, the coordinate value of target W is output to host computer by serial interface, and the positioning of target by passive optical pulse signal is completed.The present application also includes a kind of system for target positioning using passive optical pulse signal for realizing the method.

Description

Technical Field

[0001] This invention relates to a method for target localization, specifically to a method and system for target localization using passive optical pulse signals. Background Technology

[0002] Currently, GPS positioning is widely used for wilderness rescue and search and rescue. This involves using a GPS receiver to obtain signals from multiple GPS satellites, calculating the GPS receiver's location information, and then sending a distress call. This method requires the party requesting help to be equipped with a GPS receiver and to send out a distress message.

[0003] Without GPS receivers, people seeking help typically attract the attention of rescuers by marking locations, starting fires, or making smoke. During the search and rescue process, lidar is generally used for ranging and positioning. Lidar calculates the distance to the target object by actively emitting laser pulses and calculating the time difference between the emitted and received light. This search and rescue method has significant limitations and relies on lidar to actively emit pulse light sources for ranging and positioning.

[0004] There are currently no reports on using passive receivers of light sources emitted by targets for target localization. Therefore, methods for using passive signals for target localization are worth further research and exploration. Summary of the Invention

[0005] This invention addresses the problem in existing technologies that cannot locate targets by passively receiving light sources emitted by the target. It proposes a method and system for target localization using passive optical pulse signals.

[0006] The inventive concept of this invention is as follows: by using photoelectric sensors at different locations to receive passive periodic pulse light signals, calculating the phase difference of the periodic light pulse signals received by different photoelectric sensors, obtaining the distance difference between the light pulse signals and different photoelectric sensors, and locating the target based on the obtained distance difference.

[0007] To achieve the above objectives, the technical solution proposed by this invention is as follows:

[0008] A method for target localization using passive optical pulse signals, characterized by the following steps:

[0009] S1. Establish a target positioning system that receives optical pulse signals; wherein the optical pulse signal is a pulse light source of a specific wavelength;

[0010] S2. Arrange four photoelectric sensors A, B, C, and D along the axis. Set the direction of the four photoelectric sensors along the axis as the x-axis and the direction perpendicular to the x-axis as the y-axis. Establish a rectangular coordinate system with A as the origin. The target W to be located is located in the rectangular coordinate system constructed by the x-axis and y-axis.

[0011] S3. The distance corresponding to the pulse time interval between photoelectric sensors A and B is calculated using the phase calculation module. The distance corresponding to the pulse time interval between sensors C and D The angles formed by the straight lines WA and WC connecting photoelectric sensors A and C and the target W with the opposite direction of the X-axis are set as θ and α, respectively. The values ​​of cosθ and cosα are calculated by the phase calculation module.

[0012] S4. The position coordinate calculation module calculates the distance corresponding to the pulse time interval obtained by the phase calculation module. And the values ​​of cosθ and cosα are used to calculate the specific coordinates (Xw, Yw) of the target W in the rectangular coordinate system;

[0013] S5. Output the coordinates (Xw, Yw) of target W to the host computer through the external serial interface to complete the target positioning using passive optical pulse signals.

[0014] Furthermore, the values ​​of cosθ and cosα in step S3 are calculated using the following formula:

[0015] When θ≤90°, α≤90° , ;

[0016] When θ > 90° and α ≤ 90° , ;

[0017] When θ > 90° and α > 90° , .

[0018] Furthermore, the function of the line WA is: The formula for the function of the line WA is: The formula for the function of line WC is: .

[0019] Further, the coordinates (Xw, Yw) of target W in step S4 are obtained by the following formula: ( , ).

[0020] The system error is calculated by setting the parallel line MB of WA and the parallel line ND of WC. The system error is obtained by calculating the difference between the straight line WB and MB of the photoelectric sensors for targets W and B, and the difference between the straight lines WD and ND of the photoelectric sensors for targets W and D. The calculation formula is as follows: , Therefore, it can be seen that the systematic error generated by the present invention is small, and its accuracy in target positioning is high.

[0021] This invention also proposes a system for target positioning using passive optical pulse signals, which is used to implement the above-mentioned method for target positioning using passive optical pulse signals. Its special feature is that it includes a photoelectric conversion module, a phase calculation module, a position coordinate calculation module, and an external serial interface.

[0022] The photoelectric conversion module consists of several photoelectric sensors used to convert received optical pulse signals into electrical pulse signals.

[0023] The photoelectric conversion module transmits the electrical pulse signal to the phase calculation module. The phase calculation module calculates the phase difference of the received electrical pulse signal to obtain the distance difference between the optical pulse signal and different photoelectric sensors.

[0024] The position coordinate calculation module calculates the specific position coordinates of the emitted optical pulse signal using the distance difference obtained by the phase calculation module.

[0025] The external serial interface is used to transmit the specific location coordinates of the emitted optical pulse signal obtained by the coordinate calculation module to the host computer, thereby completing the positioning of the target using the passive optical pulse signal.

[0026] The beneficial effects of this invention are as follows:

[0027] [1] The method of target positioning using passive optical pulse signals in this invention has high measurement accuracy and is easy to implement in hardware.

[0028] [2] In this invention, a mathematical model is established to calculate the phase difference of the periodic light pulse signal received by different photoelectric sensors, and the distance difference between the light pulse signal and different photoelectric detectors is obtained. The target is located based on the obtained distance difference. Its positioning principle is simple and its positioning accuracy is high. When locating distant targets, its positioning method is more convenient and easy to locate quickly.

[0029] [3] The passive optical pulse signal target positioning system of the present invention does not need to actively emit pulse light, but relies on receiving the optical pulse emitted by the target to be positioned for positioning. It has high positioning accuracy, is less affected by geographical limitations, and has low system cost and is easy to implement. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the mathematical model of a method for target localization using passive optical pulse signals according to the present invention;

[0031] Figure 2 This is a schematic diagram of the mathematical model used for calculation when θ≤90° and α≤90° in the target localization method of this invention.

[0032] Figure 3 This is a schematic diagram of the mathematical model used for calculation when θ > 90° and α ≤ 90° in the target localization method of this invention.

[0033] Figure 4 This is a schematic diagram of the mathematical model used for calculation when θ > 90° and α > 90° in the target positioning method of this invention.

[0034] Figure 5 This is a schematic diagram of the phase detection method in an embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of a system for target localization using passive optical pulse signals according to the present invention.

[0036] Reference numerals: 1-Photoelectric sensor, 2-Phase calculation module, 3-Position coordinate calculation module, 4-Serial interface, 5-Host computer. Detailed Implementation

[0037] This invention provides a method for target localization using passive optical pulse signals. It utilizes photoelectric sensors at different locations to receive passive periodic pulse optical signals, generate periodic electrical pulse signals, calculate the phase difference of the periodic optical pulses received by different sensors, obtain the distance difference between the optical pulses and different sensors, and use the calculated distance difference to locate the target.

[0038] In simple terms, if the periodic pulse signal received by the first photoelectric sensor is subtracted from the periodic pulse signal received by the second photoelectric sensor, a new sinusoidal signal is formed. By detecting the phase of this signal, the distance difference between the periodic light pulse and the two sensors can be calculated. The position of the light source emitting the light pulse can be obtained through calculation using an approximate mathematical model, thus enabling the localization of the light pulse emitting source.

[0039] A method for target localization using passive optical pulse signals includes the following steps:

[0040] S1. Establish a target positioning system that receives optical pulse signals;

[0041] S2. Arrange four photoelectric sensors A, B, C, and D along the axis. Set the direction of the four photoelectric sensors along the axis as the x-axis and the direction perpendicular to the x-axis as the y-axis. Establish a rectangular coordinate system with A as the origin. The target W to be located is located in the rectangular coordinate system constructed by the x-axis and y-axis.

[0042] S3. The distance corresponding to the pulse time interval between photoelectric sensors A and B is calculated by phase calculation module 2. The distance corresponding to the pulse time interval between sensors C and D The angles formed by the straight lines WA and WC connecting photoelectric sensors A and C and the target W with the X-axis are set to θ and α, respectively. The values ​​of cosθ and cosα are calculated by the phase calculation module 2.

[0043] S4, Position coordinate calculation module 3 calculates the distance corresponding to the pulse time interval obtained by phase calculation module 2. And the values ​​of cosθ and cosα are used to calculate the specific coordinates (Xw, Yw) of the target W in the rectangular coordinate system;

[0044] S5. Output the coordinates (Xw, Yw) of target W to host computer 5 through external serial interface 4 to complete the target positioning using passive optical pulse signal.

[0045] Depend on Figure 1 It can be seen that point W is the position of the target to be located in the Cartesian coordinate system, and points A, B, C, and D are the positions of the four photoelectric sensors in the Cartesian coordinate system. When AB = CD = 0.1m, the distances between AB and CD relative to the distance to the target to be located are negligible, that is, the angles between WA and WB, and between WC and WD are almost 0.

[0046] Therefore, by Figure 2 The established mathematical model shows that point W is the intersection of WA and WC.

[0047] In step S3, the values ​​of cosθ and cosα are calculated using the following formula:

[0048] 1) When θ≤90°, α≤90°, , ;

[0049] 2) When θ > 90° and α ≤ 90°, , ;

[0050] 3) When θ > 90° and α > 90°, , ;

[0051] The solution function for line WA is:

[0052] (1)

[0053] The function for solving line WC is:

[0054] (2), .

[0055] The coordinates of point W can be obtained from formulas (1) and (2).

[0056] ( C , C )

[0057] Set the parallel line MB of WA and the parallel line ND of WC. Calculate the system error by measuring the difference between the straight lines WB and MB of the photoelectric sensors for targets W and B, and the difference between the straight lines WD and ND of the photoelectric sensors for targets W and D. The calculation formula is as follows: , Therefore, it can be seen that the systematic error generated by the present invention is small, and its accuracy in target positioning is high.

[0058] This invention employs a method that uses four photoelectric sensors arranged in a straight line to receive periodic pulse light signals emitted by the target and accurately locate the target. This method is characterized by its simple principle, ease of hardware implementation, and high measurement accuracy. It can be applied to fields such as field search and rescue, indoor positioning, and sensing systems equipped with laser ranging devices.

[0059] The present invention also proposes a system for target positioning using passive optical pulse signals, which is used to implement the above-mentioned method for target positioning using passive optical pulse signals, including a photoelectric conversion module 1, a phase calculation module 2, a position coordinate calculation module 3, an external serial interface 4, and a host computer 5;

[0060] The photoelectric conversion module 1 consists of several photoelectric sensors used to convert received light pulse signals into electrical pulse signals. The photoelectric conversion module 1 transmits the electrical pulse signals to the phase calculation module 2. The phase calculation module 2 calculates the phase difference of the received electrical pulse signals to obtain the distance difference between the light pulse signals and different photoelectric sensors. The position coordinate calculation module 3 calculates the specific position coordinates of the emitted light pulse signal based on the distance difference obtained by the phase calculation module 2. The external serial interface 4 is used to transmit the specific position coordinates of the emitted light pulse signal obtained by the coordinate calculation module 3 to the host computer 5, thereby completing the target positioning using passive light pulse signals.

Claims

1. A method for target localization using passive optical pulse signals, characterized in that, Includes the following steps: S1. Establish a target positioning system that receives optical pulse signals; S2. Arrange four photoelectric sensors A, B, C, and D along the axis. Set the direction of the four photoelectric sensors along the axis as the x-axis and the direction perpendicular to the x-axis as the y-axis. Establish a rectangular coordinate system with A as the origin. The target W to be located is located in the rectangular coordinate system constructed by the x-axis and y-axis. S3. The distance corresponding to the pulse time interval between photoelectric sensors A and B is calculated by the phase calculation module (2). The distance corresponding to the pulse time interval between sensors C and D The angles formed by the straight lines WA and WC connecting photoelectric sensors A and C and the target W with the opposite direction of the X-axis are set as θ and α, respectively. The values ​​of cosθ and cosα are calculated by the phase calculation module. S4, Position coordinate calculation module (3) The distance corresponding to the pulse time interval calculated by the phase calculation module And the values ​​of cosθ and cosα are used to calculate the specific coordinates (Xw, Yw) of the target W in the rectangular coordinate system; S5. Output the coordinates (Xw, Yw) of the target W to the host computer (5) through the external serial interface (4) to complete the positioning of the target by passive optical pulse signal.

2. The method for target localization using passive optical pulse signals according to claim 1, characterized in that: The values ​​of cosθ and cosα in step S3 are calculated using the following formula: When θ≤90°, α≤90° , ; When θ > 90° and α ≤ 90° , ; When θ > 90° and α > 90° , .

3. The method for target localization using passive optical pulse signals according to claim 2, characterized in that: The function formula for the line WA is: The functional formula for the line WC is: ; in Let x be the x-coordinate of sensor C.

4. The method for target localization using passive optical pulse signals according to claim 3, characterized in that: The coordinates (Xw, Yw) of target W in step S4 are obtained by the following formula: , ).

5. A system for target localization using passive optical pulse signals, used to implement the method for target localization using passive optical pulse signals as described in claims 1-4, characterized in that: It includes a photoelectric conversion module (1), a phase calculation module (2), a position coordinate calculation module (3), and an external serial interface (4); The photoelectric conversion module (1) consists of several photoelectric sensors used to convert the received light pulse signal into an electrical pulse signal; The photoelectric conversion module (1) transmits the electrical pulse signal to the phase calculation module (2). The phase calculation module (2) calculates the phase difference of the received electrical pulse signal to obtain the distance difference between the optical pulse signal and different photoelectric sensors. The position coordinate calculation module (3) calculates the specific position coordinates of the emitted light pulse signal by using the distance difference obtained by the phase calculation module (2); The external serial interface (4) is used to transmit the specific position coordinates of the emitted light pulse signal obtained by the coordinate calculation module (3) to the host computer (5), thereby completing the positioning of the target using the passive light pulse signal.

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