Passive distance measurement method, device and equipment for fixed target and storage medium

Abstract

The invention discloses a passive distance measurement method, device and equipment for a fixed target and a storage medium, and the method comprises the steps: recording the first position information and first attitude information of a motion platform, and a first elevation angle and a first direction angle of the fixed target at a view field point of a camera when the fixed target is in a view field range of the camera; after keeping the motion platform continuously moving for a certain distance, recording second position information and second attitude information of the motion platform again, and recording a second elevation angle and a second direction angle of the fixed target at the view field point of the camera; utilizing the first position information, the first attitude information, the second position information, the second attitude information, the first altitude angle, the first direction angle, the second altitude angle and the second direction angle to calculate actual coordinates of the fixed target; and calculating the distance between the fixed target and the moving platform according to the actual coordinates. According to the invention, high-precision passive distance measurement of a fixed target can be realized.

Description

Technical Field

[0001] The present application relates to the field of ranging technology, and in particular to a passive ranging method, apparatus, device and storage medium for a fixed target. Background Art

[0002] Distance measurement (odometry) is a core sensing requirement in numerous fields, including robotic navigation, autonomous driving, industrial automation, security monitoring, and augmented reality. To obtain distance information from target objects, the industry has developed and widely adopted a variety of technical solutions, primarily including active sensing-based reflection ranging and passive vision-based imaging ranging. However, existing mainstream technical solutions have varying degrees of limitations in terms of cost, accuracy, applicability, and platform adaptability.

[0003] Active reflection ranging technologies primarily include laser ranging and ultrasonic ranging. They actively transmit specific signals (laser pulses or ultrasonic pulses) to the target, measure the time difference (ToF) or phase difference between the transmitted and received reflected signals, and calculate the target distance based on the signal propagation speed. This technology generally offers high ranging accuracy and reliability, is less affected by ambient lighting conditions (especially lasers), and can actively detect objects. However, it requires dedicated hardware modules including a signal transmitter and receiver, resulting in a relatively complex system structure and high manufacturing costs (especially for high-performance lidars). It is also susceptible to environmental interference. Passive visual ranging technologies primarily include monocular and binocular vision ranging. However, monocular camera image ranging is limited by the need to clearly identify the boundaries of fixed targets, and ranging accuracy is limited by the accuracy of estimating the fixed target's size. Binocular ranging requires higher camera angular resolution, and the greater the distance between the two cameras, the higher the accuracy, thus placing requirements on the platform installation location and size. Summary of the Invention

[0004] In view of this, the present application provides a fixed target passive ranging method, apparatus, device and storage medium to solve the problems of high cost and low accuracy of existing ranging methods.

[0005] To solve the above technical problems, a technical solution adopted in the present application is: providing a passive ranging method for a fixed target, which includes: when the fixed target is within the field of view of a camera preset on a motion platform, recording the first position information and first posture information of the motion platform in a platform coordinate system pre-constructed based on the motion platform, as well as the first elevation angle and first direction angle of the fixed target at the camera's field of view; keeping the motion platform in continuous motion and when the fixed target is within the field of view of the camera and meets a second preset condition, recording the second position information and second posture information of the motion platform in the platform coordinate system, as well as the second elevation angle and second direction angle of the fixed target at the camera's field of view; using the first position information, first posture information, second position information, second posture information, first elevation angle, first direction angle, second elevation angle, and second direction angle to calculate the actual coordinates of the fixed target in the platform coordinate system; and calculating the distance between the fixed target and the motion platform based on the actual coordinates.

[0006] As a further improvement of the present application, the first position information and first posture information of the moving platform in the platform coordinate system pre-constructed based on the moving platform, as well as the first elevation angle and first direction angle of the fixed target at the camera's field of view are recorded, including: confirming the first pixel range occupied by the fixed target or the typical characteristic part of the fixed target in the camera's field of view; when the first pixel range does not reach the preset range, keeping the moving platform moving in the direction approaching the fixed target until the first pixel range reaches the preset range, and then recording the first position information and first posture information of the moving platform in the platform coordinate system pre-constructed based on the moving platform, as well as the first elevation angle and first direction angle of the fixed target at the camera's field of view.

[0007] As a further improvement of the present application, the motion platform is kept in continuous motion and when the fixed target is within the field of view of the camera and meets the second preset condition, the second position information and second posture information of the motion platform in the platform coordinate system, as well as the second elevation angle and second direction angle of the fixed target at the camera field of view point are recorded, including: keeping the motion platform in continuous motion and confirming in real time the second pixel range occupied by the fixed target or the typical characteristic part of the fixed target in the camera field of view, and at the same time confirming the boundary distance between the position of the fixed target in the camera field of view and the boundary of the field of view; when the second pixel range reaches the preset range and the boundary distance meets the preset distance condition, the second position information and second posture information of the motion platform in the platform coordinate system, as well as the second elevation angle and second direction angle of the fixed target at the camera field of view point are recorded.

[0008] As a further improvement of this application, the preset distance condition is expressed as:

[0009] d <k*v*t;

[0010] Where d represents the boundary distance, k represents a preset constant, v represents the relative velocity between the fixed target and the moving platform, and t represents the system response delay.

[0011] As a further improvement of the present application, the preset range is set to a size of 6*6 pixels.

[0012] As a further improvement of the present application, the actual coordinates of the fixed target in the platform coordinate system are calculated using the first position information, the first posture information, the second position information, the second posture information, the first elevation angle, the first direction angle, the second elevation angle, and the second direction angle, including: using the first posture information, the first elevation angle, and the first direction angle to calculate the first elevation angle and the first direction angle between the moving platform and the fixed target in the platform coordinate system, and using the second posture information, the second elevation angle, and the second direction angle to calculate the second elevation angle and the second direction angle between the moving platform and the fixed target in the platform coordinate system; using the first elevation angle, the first direction angle, the second elevation angle, the second direction angle, the first position information, and the second position information to calculate the actual coordinates of the fixed target.

[0013] As a further improvement of this application, the calculation process of the actual coordinates is expressed as:

[0014] α1=arcsin[-sin(η1)]*sin(ψ1)+cos(η1)*cos(ψ1)*sin(γ1);

[0015] β1=arcsin{-cos(η1)*sin(σ1)*[(sin(θ1)*sin(ψ1)+cos(θ1)*sin(ψ1)*cos(γ1))]+sin(η1) *sin(σ1)*[-cos(ψ1)sin(γ1)+sin(θ1)*sin(ψ1)*cos(γ1)]+cos(σ1)*[cos(ψ1)*cos(γ1)]};

[0016] α2=arcsin[-sin(η2)]*sin(ψ2)+cos(η2)*cos(ψ2)*sin(γ2);

[0017] β2=arcsin{-cos(η2)*sin(σ2)*[(sin(θ2)*sin(ψ2)+cos(θ2)*sin(ψ2)*cos(γ2))]+sin(η2) *sin(σ2)*[-cos(ψ2)sin(γ2)+sin(θ2)*sin(ψ2)*cos(γ2)]+cos(σ2)*[cos(ψ2)*cos(γ2)]};

[0018]

[0019] Among them, α i represents the elevation angle between the moving platform and the fixed target in the platform coordinate system at the time of the i-th recording, β i represents the direction angle between the moving platform and the fixed target in the platform coordinate system at the time of the i-th recording, (θ i , ψ i , γ i ) represents the posture information of the motion platform in the platform coordinate system at the time of the i-th recording, η i Indicates the height angle of the fixed target in the camera field of view during the i-th recording, σ i Indicates the direction angle of the fixed target in the camera field of view during the i-th recording, (x i ,y i , z i ) represents the position information of the motion platform at the time of the i-th recording, i=1,2, (x B ,y B , z B ) represents the actual coordinates of the fixed target in the platform coordinate system.

[0020] To solve the above technical problems, another technical solution adopted in the present application is: to provide a passive ranging device for a fixed target, which includes: a first measurement module, which is used to record the first position information and first posture information of the moving platform in a platform coordinate system pre-constructed based on the moving platform, as well as the first elevation angle and first direction angle of the fixed target at the camera's field of view when the fixed target is within the field of view of a camera preset on the moving platform; a second measurement module, which is used to keep the moving platform in continuous motion and, when the fixed target is within the field of view of the camera and meets a second preset condition, record the second position information and second posture information of the moving platform in the platform coordinate system, as well as the second elevation angle and second direction angle of the fixed target at the camera's field of view; a coordinate calculation module, which is used to calculate the actual coordinates of the fixed target in the platform coordinate system using the first position information, first posture information, second position information, second posture information, first elevation angle, first direction angle, second elevation angle, and second direction angle; and a distance calculation module, which is used to calculate the distance between the fixed target and the moving platform based on the actual coordinates.

[0021] To solve the above technical problems, another technical solution adopted in the present application is: providing a computer device, wherein the computer device includes a processor and a memory coupled to the processor, wherein program instructions are stored in the memory, and when the program instructions are executed by the processor, the processor executes the steps of the passive ranging method for a fixed target as described in any one of the above items.

[0022] In order to solve the above technical problems, another technical solution adopted by the present application is: providing a storage medium storing program instructions of the passive ranging method for fixed targets that can implement any of the above items.

[0023] The beneficial effects of the present application are as follows: the passive ranging method for fixed targets of the present application utilizes a single motion platform to observe the same fixed target at two different time and space points during continuous motion, deeply integrates the precise time and space information and posture of the motion platform with the precise angle information of the target in the image, and fully considers the influence of the posture change of the motion platform on the camera line of sight vector when calculating the real target angle in the platform coordinate system, and then based on the spatial geometric relationship formed by the two time and space points, the three-dimensional coordinates of the fixed target in the platform coordinate system are accurately solved by using the triangulation principle, and finally the distance between the motion platform and the fixed target is calculated according to the three-dimensional coordinates. It only relies on the camera carried by the motion platform itself to passively receive the optical information of the target, and does not require the target to actively cooperate or transmit signals, thereby realizing passive ranging of the fixed target, and has low requirements for ranging hardware, thereby reducing the overall production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 1 is a flow chart of a passive ranging method for a fixed target according to an embodiment of the present invention;

[0025] Figure 2 1 is a schematic diagram of the functional modules of a passive ranging device for a fixed target according to an embodiment of the present invention;

[0026] Figure 3 is a schematic structural diagram of a computer device according to an embodiment of the present invention;

[0027] Figure 4 It is a schematic structural diagram of a storage medium according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0029] The terms "first," "second," and "third" in this application are used only for descriptive purposes and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of such features. In the description of this application, "multiple" means at least two, for example, two, three, etc., unless otherwise specifically defined. All directional indications in the embodiments of this application (such as up, down, left, right, front, back...) are only used to explain the relative positional relationship, movement, etc. between the components under a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications also change accordingly. In addition, the terms "including" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products, or devices.

[0030] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0031] Figure 1 FIG is a flow chart of a passive ranging method for a fixed target according to an embodiment of the present invention. It should be noted that the method of the present invention is not limited to the passive ranging method of the fixed target according to an embodiment of the present invention. Figure 1 The process sequence shown is limited. Figure 1 As shown, the passive ranging method for a fixed target includes the following steps:

[0032] Step S1: When the fixed target is within the field of view of a camera preset on the motion platform, record the first position information and first posture information of the motion platform in a platform coordinate system pre-constructed based on the motion platform, as well as the first elevation angle and first direction angle of the fixed target at the camera's field of view point.

[0033] It should be noted that the motion platform includes but is not limited to drones, aircraft, vehicles and other devices. Before measuring the distance, on a motion platform with a positioning and attitude measurement device, a camera is installed at a position that is convenient for observing a fixed target. The field of view angle of the camera should range from 0.01 times to 1 times the positioning accuracy of the motion platform, and the maximum should not exceed 60°. The direction of the camera should be consistent with the direction of the motion platform. At this time, the height angle and direction angle of the camera installed on the motion platform are calibrated to 0°. By setting the camera on the motion platform and constructing a reference coordinate system, a platform coordinate system, and a camera coordinate system, the reference coordinate system is constructed with the center of the earth as the origin, the platform coordinate system is constructed with the center position of the platform positioning and orientation device as the origin, and the camera coordinate system is constructed with the center position of the camera as the origin.

[0034] Specifically, when the fixed target enters the field of view of the camera, the camera is controlled to capture the first image of the fixed target, and the first position information and first posture information of the motion platform in the platform coordinate system pre-constructed based on the motion platform are recorded. At the same time, by analyzing the first image of the fixed target, the first elevation angle and first direction angle of the fixed target at the camera field of view point are obtained.

[0035] Furthermore, in order to accurately measure the distance between the motion platform and the fixed target, in some embodiments, in step S1, the step of recording the first position information and first posture information of the motion platform in a platform coordinate system pre-constructed based on the motion platform, and the first elevation angle and first direction angle of the fixed target at the camera field of view point specifically includes:

[0036] 1. Confirm the first pixel range occupied by the fixed target or the typical feature part of the fixed target in the camera field of view.

[0037] 2. When the first pixel range does not reach the preset range, the motion platform continues to move toward the fixed target until the first pixel range reaches the preset range, and then records the first position information and first posture information of the motion platform in the platform coordinate system pre-built based on the motion platform, as well as the first elevation angle and first direction angle of the fixed target in the camera's field of view.

[0038] Specifically, the typical characteristic parts of a fixed target are used to characterize the entire fixed target. Before capturing an image of the fixed target, it is necessary to ensure that the first pixel range occupied by the image of the fixed target or the image of the typical characteristic parts of the fixed target within the camera's field of view reaches a preset range, thereby ensuring that the camera can accurately identify the fixed target.

[0039] Furthermore, in the above embodiment, the preset range is set to a size of 6*6 pixels.

[0040] Step S2: Keep the motion platform in continuous motion and when the fixed target is within the field of view of the camera and meets the second preset condition, record the second position information and second posture information of the motion platform in the platform coordinate system, as well as the second elevation angle and second direction angle of the fixed target at the camera field of view point.

[0041] Specifically, after completing the first recording, the motion platform is kept in motion, and the position of the fixed target in the field of view of the camera is monitored in real time. In order to accurately measure the distance between the motion platform and the fixed target, the fixed target also needs to be within the field of view of the camera during the second recording. The second position information and the second posture information of the motion platform in the platform coordinate system are then recorded, and a second image of the fixed target is captured at the same time. The second image is analyzed to obtain the second elevation angle and the second direction angle of the fixed target at the camera field of view. It should be noted that in order to ensure the accuracy of the final distance measurement, the position of the fixed target recorded for the first time and the position of the fixed target recorded for the second time should be as far as possible, thereby improving the distance measurement accuracy. Therefore, in this embodiment, a second preset condition is set. The second preset condition can be a distance threshold between the two recorded positions of the fixed target, thereby ensuring that the distance interval between the two records is far enough.

[0042] Furthermore, step S2 specifically includes:

[0043] 1. Keep the motion platform in continuous motion and confirm in real time the second pixel range occupied by the fixed target or the typical feature part of the fixed target in the camera's field of view, and at the same time confirm the boundary distance between the position of the fixed target in the camera's field of view and the boundary of the field of view.

[0044] 2. When the second pixel range reaches the preset range and the boundary distance meets the preset distance condition, the second position information and the second posture information of the moving platform in the platform coordinate system, as well as the second elevation angle and the second direction angle of the fixed target in the camera field of view are recorded.

[0045] Among them, the preset distance condition is expressed as:

[0046] d <k*v*t;

[0047] Where d represents the boundary distance, k represents a preset constant, v represents the relative velocity between the fixed target and the moving platform, and t represents the system response delay.

[0048] Specifically, to ensure that the fixed target is still within the field of view of the camera during the second recording, thus avoiding invalidation of the recorded data, in this embodiment, a preset distance condition d < k*v*t is defined. The essence of this inequality is a safety boundary condition, which defines the moment for triggering the second recording. The "buffer distance" d between the fixed target and the edge of the camera's field of view must be less than the "safety distance" defined by k*v*t. k*v*t represents the maximum displacement (multiplied by the safety factor k) that the moving platform may cause relative to the fixed target at a speed v within the system delay time t. If d is less than this "safety distance", it means that if recording is not immediately performed at this time, the fixed target is very likely to move out of the field of view before completing the current measurement cycle. Therefore, this embodiment defines a preset distance condition to ensure the reliability and success rate of measurement during the continuous movement of the moving platform.

[0049] Step S3: Calculate the actual coordinates of the fixed target in the platform coordinate system using the first position information, the first attitude information, the second position information, the second attitude information, the first elevation angle, the first azimuth angle, the second elevation angle, and the second azimuth angle.

[0050] Further, step S3 specifically includes:

[0051] 1. Calculate the first elevation angle and the first azimuth angle between the moving platform and the fixed target in the platform coordinate system using the first attitude information, the first elevation angle, and the first azimuth angle, and calculate the second elevation angle and the second azimuth angle between the moving platform and the fixed target in the platform coordinate system using the second attitude information, the second elevation angle, and the second azimuth angle.

[0052] 2. Calculate the actual coordinates of the fixed target using the first elevation angle, the first azimuth angle, the second elevation angle, the second azimuth angle, the first position information, and the second position information.

[0053] Further, the calculation process of the actual coordinates is expressed as:

[0054] α1 = arcsin[-sin(η1)]*sin(ψ1) + cos(η1)*cos(ψ1)*sin(γ1);

[0055] β1 = arcsin{-cos(η1)*sin(σ1)*[(sin(θ1)*sin(ψ1) + cos(θ1)*sin(ψ1)*cos(γ1))] + sin(η1)*sin(σ1)*[-cos(ψ1)sin(γ1) + sin(θ1)*sin(ψ1)*cos(γ1)] + cos(σ1)*[cos(ψ1)*cos(γθ1)]};

[0056] α2=arcsin[-sin(η2)]*sin(ψ2)+cos(η2)*cos(ψ2)*sin(γ2);

[0057] β2=arcsin{-cos(η2)*sin(σ2)*[(sin(θ2)*sin(ψ2)+cos(θ2)*sin(ψ2)*cos(γ2))]+sin(η2) *sin(σ2)*[-cos(ψ2)sin(γ2)+sin(θ2)*sin(ψ2)*cos(γ2)]+cos(σ2)*[cos(ψ2)*cos(γ2)]};

[0058]

[0059] Among them, α i represents the elevation angle between the moving platform and the fixed target in the platform coordinate system at the time of the i-th recording, β i represents the direction angle between the moving platform and the fixed target in the platform coordinate system at the time of the i-th recording, (θ i , ψ i , γ i ) represents the posture information of the motion platform in the platform coordinate system at the time of the i-th recording, η i Indicates the height angle of the fixed target in the camera field of view during the i-th recording, σ i Indicates the direction angle of the fixed target in the camera field of view during the i-th recording, (x i ,y i , z i ) represents the position information of the motion platform at the time of the i-th recording, i=1,2, (x B ,y B , z B ) represents the actual coordinates of the fixed target in the platform coordinate system.

[0060] Step S4: Calculate the distance between the fixed target and the moving platform based on the actual coordinates.

[0061] Specifically, after calculating the actual coordinates of the fixed target in the platform coordinate system, the distance between the fixed target and the moving platform is calculated in combination with the position coordinates of the moving platform in the platform coordinate system. The platform coordinate system is constructed with the moving platform as the center. Therefore, the position coordinates of the moving platform are expressed as (0, 0, 0). Therefore, the distance calculation between the fixed target and the moving platform can be expressed as:

[0062] The passive ranging method for fixed targets of this embodiment utilizes a single motion platform to observe the same fixed target at two different spatiotemporal points during continuous motion, deeply integrating the precise spatiotemporal information and posture of the motion platform with the precise angular information of the target in the image. When calculating the true target angle in the platform coordinate system, the influence of the motion platform's posture change on the camera's line of sight is fully considered. Based on the spatial geometric relationship formed by the two spatiotemporal points, the three-dimensional coordinates of the fixed target in the platform coordinate system are accurately calculated using the principle of triangulation. Finally, the distance between the motion platform and the fixed target is calculated based on the three-dimensional coordinates. The method relies only on the camera carried by the motion platform itself to passively receive the optical information of the target, without the need for the target to actively cooperate or transmit signals, thereby achieving passive ranging of fixed targets, and having low requirements for ranging hardware, thereby reducing overall production costs.

[0063] Figure 2 FIG. 1 is a functional module diagram of a passive ranging device for a fixed target according to an embodiment of the present invention. Figure 2 As shown, the passive distance measuring device 20 for a fixed target includes: a first measurement module 100 , a second measurement module 200 , a coordinate calculation module 300 and a distance calculation module 400 .

[0064] The first measurement module 100 is configured to record, when a fixed target is within the field of view of a camera preset on the motion platform, first position information and first posture information of the motion platform in a platform coordinate system pre-established based on the motion platform, as well as a first elevation angle and a first direction angle of the fixed target at a point in the field of view of the camera;

[0065] The second measurement module 200 is configured to keep the motion platform in continuous motion and, when the fixed target is within the field of view of the camera and satisfies a second preset condition, record second position information and second posture information of the motion platform in the platform coordinate system, as well as a second elevation angle and a second direction angle of the fixed target at the field of view of the camera;

[0066] A coordinate calculation module 300 is configured to calculate the actual coordinates of the fixed target in the platform coordinate system using the first position information, the first posture information, the second position information, the second posture information, the first elevation angle, the first direction angle, the second elevation angle, and the second direction angle;

[0067] The distance calculation module 400 is used to calculate the distance between the fixed target and the moving platform according to the actual coordinates.

[0068] Optionally, the first measurement module 100 performs an operation of recording the first position information and first posture information of the moving platform in a platform coordinate system pre-constructed based on the moving platform, as well as the first elevation angle and first direction angle of the fixed target at the camera's field of view, specifically including: confirming the first pixel range occupied by the fixed target or the typical characteristic part of the fixed target in the camera's field of view; when the first pixel range does not reach the preset range, keeping the moving platform moving in the direction close to the fixed target until the first pixel range reaches the preset range, and then recording the first position information and first posture information of the moving platform in the platform coordinate system pre-constructed based on the moving platform, as well as the first elevation angle and first direction angle of the fixed target at the camera's field of view.

[0069] Optionally, the second measurement module 200 executes an operation of keeping the moving platform in continuous motion and recording the second position information and second posture information of the moving platform in the platform coordinate system, as well as the second elevation angle and second direction angle of the fixed target at the camera's field of view when the fixed target is within the camera's field of view and satisfies a second preset condition. Specifically, the operation includes: keeping the moving platform in continuous motion and confirming in real time the second pixel range occupied by the fixed target or a typical characteristic part of the fixed target in the camera's field of view, and at the same time confirming the boundary distance between the position of the fixed target in the camera's field of view and the boundary of the field of view; when the second pixel range reaches the preset range and the boundary distance satisfies the preset distance condition, recording the second position information and second posture information of the moving platform in the platform coordinate system, as well as the second elevation angle and second direction angle of the fixed target at the camera's field of view.

[0070] Optionally, the preset distance condition is expressed as:

[0071] d <k*v*t;

[0072] Where d represents the boundary distance, k represents a preset constant, v represents the relative velocity between the fixed target and the moving platform, and t represents the system response delay.

[0073] Optionally, the preset range is set to a size of 6*6 pixels.

[0074] Optionally, the coordinate calculation module 300 performs an operation of calculating the actual coordinates of the fixed target in the platform coordinate system using the first position information, the first posture information, the second position information, the second posture information, the first elevation angle, the first direction angle, the second elevation angle, and the second direction angle, specifically including: using the first posture information, the first elevation angle, and the first direction angle to calculate the first elevation angle and the first direction angle between the moving platform and the fixed target in the platform coordinate system, and using the second posture information, the second elevation angle, and the second direction angle to calculate the second elevation angle and the second direction angle between the moving platform and the fixed target in the platform coordinate system; using the first elevation angle, the first direction angle, the second elevation angle, the second direction angle, the first position information, and the second position information to calculate the actual coordinates of the fixed target.

[0075] Alternatively, the calculation process of the actual coordinates is expressed as:

[0076] α1=arcsin[-sin(η1)]*sin(ψ1)+cos(η1)*cos(ψ1)*sin(γ1);

[0077] β1=arcsin{-cos(η1)*sin(σ1)*[(sin(θ1)*sin(ψ1)+cos(θ1)*sin(ψ1)*cos(γ1))]+sin(η1) *sin(σ1)*[-cos(ψ1)sin(γ1)+sin(θ1)*sin(ψ1)*cos(γ1)]+cos(σ1)*[cos(ψ1)*cos(γ1)]};

[0078] α2=arcsin[-sin(η2)]*sin(ψ2)+cos(η2)*cos(ψ2)*sin(γ2);

[0079] β2=arcsin{-cos(η2)*sin(σ2)*[(sin(θ2)*sin(ψ2)+cos(θ2)*sin(ψ2)*cos(γ2))]+sin(η2) *sin(σ2)*[-cos(ψ2)sin(γ2)+sin(θ2)*sin(ψ2)*cos(γ2)]+cos(σ2)*[cos(ψ2)*cos(γ2)]};

[0080]

[0081] Among them, α i represents the elevation angle between the moving platform and the fixed target in the platform coordinate system at the time of the i-th recording, β i represents the direction angle between the moving platform and the fixed target in the platform coordinate system at the time of the i-th recording, (θ i , ψi , γ i ) represents the posture information of the motion platform in the platform coordinate system at the time of the i-th recording, η i Indicates the height angle of the fixed target in the camera field of view during the i-th recording, σ i Indicates the direction angle of the fixed target in the camera field of view during the i-th recording, (x i ,y i , z i ) represents the position information of the motion platform at the time of the i-th recording, i=1,2, (x B ,y B , z B ) represents the actual coordinates of the fixed target in the platform coordinate system.

[0082] For other details of the technical solutions for implementing the modules in the passive ranging device for a fixed target in the above embodiment, please refer to the description of the passive ranging method for a fixed target in the above embodiment, which will not be repeated here.

[0083] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similarities between the various embodiments can be referred to in conjunction with each other. For device embodiments, since they are generally similar to method embodiments, their description is relatively simple, and for relevant details, reference can be made to the description of the method embodiments.

[0084] See also Figure 3 , Figure 3 FIG. 1 is a schematic diagram of the structure of a computer device according to an embodiment of the present invention. Figure 3 As shown, the computer device 30 includes a processor 31 and a memory 32 coupled to the processor 31. The memory 32 stores program instructions. When the program instructions are executed by the processor 31, the processor 31 executes the steps of the passive ranging method for fixed targets described in any of the above embodiments.

[0085] The processor 31 may also be referred to as a resource (Central Processing Unit). The processor 31 may be an integrated circuit chip having signal processing capabilities. The processor 31 may also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component. The general-purpose processor may be a microprocessor or any conventional processor.

[0086] See Figure 4 , Figure 4Schematic diagram of the structure of the storage medium of an embodiment of the present invention. The storage medium of the embodiment of the present invention stores program instructions 41 that can implement the passive ranging method of the above-mentioned fixed target, wherein the program instructions 41 can be stored in the above-mentioned storage medium in the form of a software product, including a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) or a processor (processor) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, or a computer device such as a computer, a server, a mobile phone, or a tablet.

[0087] In the several embodiments provided in this application, it should be understood that the disclosed computer devices, apparatuses and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interface, device or unit, which can be electrical, mechanical or other forms.

[0088] In addition, the functional units in the various embodiments of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated units may be implemented in the form of hardware or in the form of software functional units. The above is only an implementation method of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A passive ranging method for a fixed target, characterized in that: It includes: When a fixed target is within the field of view of a camera preset on a motion platform, first position information and first posture information of the motion platform in a platform coordinate system pre-established based on the motion platform, as well as a first elevation angle and a first direction angle of the fixed target at the point in the field of view of the camera are recorded; Keeping the motion platform in continuous motion and when the fixed target is within the field of view of the camera and satisfies a second preset condition, recording second position information and second posture information of the motion platform in the platform coordinate system, as well as a second elevation angle and a second direction angle of the fixed target at the point in the field of view of the camera; Calculate the actual coordinates of the fixed target in the platform coordinate system using the first position information, the first posture information, the second position information, the second posture information, the first elevation angle, the first direction angle, the second elevation angle, and the second direction angle; The distance between the fixed target and the moving platform is calculated according to the actual coordinates.

2. The passive ranging method for a fixed target according to claim 1, characterized in that: The recording of the first position information and the first posture information of the motion platform in a platform coordinate system pre-constructed based on the motion platform, and the first elevation angle and the first direction angle of the fixed target at the camera field of view point includes: Determining a first pixel range occupied by the fixed object or a typical characteristic portion of the fixed object within the camera field of view; When the first pixel range does not reach the preset range, the motion platform continues to move in the direction approaching the fixed target until the first pixel range reaches the preset range, and then records the first position information and first posture information of the motion platform in the platform coordinate system pre-constructed based on the motion platform, as well as the first elevation angle and first direction angle of the fixed target at the camera field of view point.

3. The passive ranging method for a fixed target according to claim 2, characterized in that: The method of maintaining the continuous motion of the motion platform and recording the second position information and the second posture information of the motion platform in the platform coordinate system, and the second elevation angle and the second direction angle of the fixed target at the camera field of view point when the fixed target is within the field of view of the camera and satisfies a second preset condition, includes: Keeping the motion platform in continuous motion and confirming in real time a second pixel range occupied by the fixed object or a typical characteristic portion of the fixed object within the camera's field of view, and simultaneously confirming a boundary distance between the position of the fixed object within the camera's field of view and a boundary of the field of view; When the second pixel range reaches the preset range and the boundary distance meets the preset distance condition, the second position information and second posture information of the motion platform in the platform coordinate system, and the second elevation angle and second direction angle of the fixed target at the camera field of view point are recorded.

4. The passive ranging method for a fixed target according to claim 3, characterized in that: The preset distance condition is expressed as: d <k*v*t; Wherein, d represents the boundary distance, k represents a preset constant, v represents the relative speed between the fixed target and the moving platform, and t represents the system response delay.

5. The passive ranging method for a fixed target according to claim 3, characterized in that: The preset range is set to a size of 6*6 pixels.

6. The passive ranging method for a fixed target according to claim 1, characterized in that: The calculating the actual coordinates of the fixed target in the platform coordinate system by using the first position information, the first posture information, the second position information, the second posture information, the first elevation angle, the first direction angle, the second elevation angle, and the second direction angle includes: Calculating a first elevation angle and a first direction angle between the moving platform and the fixed target in a platform coordinate system using the first posture information, the first elevation angle, and the first direction angle, and calculating a second elevation angle and a second direction angle between the moving platform and the fixed target in a platform coordinate system using the second posture information, the second elevation angle, and the second direction angle; The actual coordinates of the fixed target are calculated using the first elevation angle, the first direction angle, the second elevation angle, the second direction angle, the first position information, and the second position information.

7. The passive ranging method for a fixed target according to claim 6, characterized in that: The calculation process of the actual coordinates is expressed as: α1=arcsin[-sin(η1)]*sin(ψ1)+cos(η1)*cos(ψ1)*sin(γ1); β1=arcsin{-cos(η1)*sin(σ1)*[(sin(θ1)*sin(ψ1)+cos(θ1)*sin(ψ1)*cos(γ1))]+sin(η1) *sin(σ1)*[-cos(ψ1)sin(γ1)+sin(θ1)*sin(ψ1)*cos(γ1)]·+cos(σ1)*[cos(ψ1)*cos(γ1)]}; α2=arcsin[-sin(η2)]*sin(ψ2)+cos(η2)*cos(ψ2)*sin(γ2); β2=arcsin{-cos(η2)*sin(σ2)*[(sin(θ2)*sin(ψ2)+cos(θ2)*sin(ψ2)*cos(γ2))]+sin(η2) *sin(σ2)*[-cos(ψ2)sin(γ2)+sin(θ2)*sin(ψ2)*cos(γ2)]+cos(σ2)*[cos(ψ2)*cos(γ2)]}; Among them, α i represents the elevation angle between the moving platform and the fixed target in the platform coordinate system at the time of the i-th recording, β i represents the direction angle between the moving platform and the fixed target in the platform coordinate system at the time of the i-th recording, (θ i , ψ i , γ i ) represents the posture information of the motion platform in the platform coordinate system at the time of the i-th recording, η i Indicates the height angle of the fixed target in the camera field of view during the i-th recording, σ i Indicates the direction angle of the fixed target in the camera field of view during the i-th recording, (x i ,y i , z i ) represents the position information of the motion platform at the time of the i-th recording, i=1,2, (x B ,y B , z B ) represents the actual coordinates of the fixed target in the platform coordinate system.

8. A passive ranging device for a fixed target, characterized in that: It includes: a first measurement module, configured to record, when a fixed target is within the field of view of a camera preset on the motion platform, first position information and first posture information of the motion platform in a platform coordinate system pre-established based on the motion platform, as well as a first elevation angle and a first direction angle of the fixed target at the point in the field of view of the camera; a second measurement module, configured to keep the motion platform in continuous motion and, when the fixed target is within the field of view of the camera and satisfies a second preset condition, record second position information and second posture information of the motion platform in the platform coordinate system, as well as a second elevation angle and second direction angle of the fixed target at the field of view of the camera; a coordinate calculation module, configured to calculate the actual coordinates of the fixed target in the platform coordinate system by using the first position information, the first posture information, the second position information, the second posture information, the first elevation angle, the first direction angle, the second elevation angle, and the second direction angle; The distance calculation module is used to calculate the distance between the fixed target and the moving platform according to the actual coordinates.

9. A computer device, characterized in that: The computer device includes a processor and a memory coupled to the processor, wherein program instructions are stored in the memory. When the program instructions are executed by the processor, the processor performs the steps of the passive ranging method for a fixed target according to any one of claims 1 to 7.

10. A storage medium, characterized in that: The device stores program instructions capable of implementing the passive ranging method for a fixed target according to any one of claims 1 to 7.

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