A telescope guidance method and guidance system based on trajectory prediction

Abstract

The present invention relates to the field of telescope external guidance technology, and specifically provides a telescope guidance method and guidance system based on trajectory prediction, wherein a target position is obtained in real time through a guidance source and sent to a trajectory prediction module, the trajectory prediction module obtains the predicted trajectory of the target and generates an equation based on the target position at the current time and three adjacent historical times, the timing system sends a trigger signal carrying time information to the frequency division module according to the guidance frequency of the telescope, the frequency division module calculates the target predicted position through the equation of the predicted trajectory based on the trigger signal and time information provided by the timing system, and guides the telescope using the target predicted position. By obtaining the predicted trajectory of the target and obtaining the target predicted position on the equation of the predicted trajectory according to the new guidance frequency, low-frequency guidance data can be converted into high-frequency guidance data, so that in the actual guidance process, the target is not easy to leave the field of view and the jitter amplitude in the field of view is reduced, thereby improving the guidance accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of telescope external guidance, and specifically provides a telescope guidance method and guidance system based on trajectory prediction. Background Art

[0002] In order to present a larger target image and show more target details, the field of view of the telescope imaging system is usually smaller than the diagonal Due to the small field of view, it is difficult for a single imaging system to capture and image an unknown target. Usually, a telescope is equipped with a capture system with a larger field of view to introduce the target into the imaging system and complete related observation tasks and scientific experiments.

[0003] Due to certain reasons, such as saving R&D costs and reducing the weight and volume of the telescope, some telescopes are not designed with a capture optical system. In this case, other optoelectronic devices with capture capabilities can be used to guide the telescope externally, so that the target enters the field of view and is imaged.

[0004] Currently, the commonly used external guidance method is network external guidance. The guidance source sends the real-time position of the target in a certain coordinate system to the local telescope main control system through the network protocol at a low frequency of 1 Hz. The main control system converts it into azimuth and pitch in the horizontal coordinate system and guides the telescope at a higher frequency.

[0005] The telescope control strategies of the main control system for external guidance usually include hysteresis guidance and linear differential guidance. Assuming that the current time is , then the lagged bootstrapping and linear difference bootstrapping are as follows:

[0006] 1. Delayed boot: The main control system will The guiding position of the moment is The guiding position at the moment will The guiding position of the moment is The guidance position at that moment is then used to differentially guide the telescope.

[0007] 2. Linear differential guidance: The main control system will Moment and The linear difference of the guide position at the moment Before the external guidance data of a certain moment arrives, this predicted data is used as the basis for guiding the telescope.

[0008] The above two guidance methods have the following problems:

[0009] 1. Delayed guidance: This method is suitable for low-speed targets in a large field of view. Even for a capture system with a large field of view, if the target moves faster, the target cannot enter the capture field of view.

[0010] 2. Linear differential guidance: This method has better guidance accuracy than hysteresis guidance. Usually, the target can be guided to the center of the field of view each time the external guidance data is updated. However, due to the acceleration of the target, the target will gradually deviate from the center before the next external guidance data update. If the field of view of the optical system is small or the target motion acceleration is large, the target will easily leave the field of view or shake violently back and forth.

[0011] When a small-field-of-view optoelectronic telescope receives real-time external guidance from other devices, the guidance frequency of the guidance source is low and the target moves quickly. The commonly used telescope guidance methods have large guidance errors. During the tracking process, the target may frequently enter and leave the field of view, or shake violently within the field of view, which is not conducive to the smooth progress of closed-loop target tracking or related scientific experiments. Summary of the invention

[0012] In order to solve the above problems, the present invention provides a telescope guidance method and guidance system based on trajectory prediction, which obtains the predicted trajectory of the target through a trajectory prediction module, and obtains the predicted position of the target on the predicted trajectory through a frequency division module according to the predicted trajectory and a trigger signal carrying time information provided by a timing system according to the guidance frequency of the telescope to guide the telescope. The guidance method and guidance system can reduce the probability of the target leaving the field of view, reduce the target jitter amplitude, and improve the guidance accuracy. The above advantages are particularly significant under the conditions of low frequency of the guidance source and small field of view of the telescope.

[0013] The telescope guidance method based on trajectory prediction provided by the present invention comprises:

[0014] S1: Acquire the target through the guidance source according to the target acquisition frequency Target position corresponding to time , Indicates time The serial number of the corresponding target location;

[0015] S2: Based on target position and in The target position is obtained by the guidance source at adjacent historical times, and the Time to The predicted trajectory of the target between times;

[0016] S3: Set the guidance frequency of the telescope, and obtain the predicted trajectory according to the guidance frequency of the telescope. Time to The predicted position of the target between times;

[0017] S4: Transmit the predicted target position to the telescope at the guidance frequency to guide the telescope to track the target.

[0018] Preferably, in S2, The value is 3.

[0019] Preferably, the equation for predicting the trajectory is:

[0020] ;

[0021] in, represents the predicted position of the target on the predicted trajectory, Indicates the time corresponding to the target predicted position, , , and They all represent the coefficients of the equation.

[0022] Preferably, the coefficients of the equation , , and The calculation method is:

[0023] ;

[0024] in, , , .

[0025] Preferably, the steering frequency of the telescope is 50 Hz or 100 Hz.

[0026] A telescope guidance system based on trajectory prediction, a telescope guidance method based on trajectory prediction, the guidance system includes a guidance source, a main control system and a timing system, the main control system includes a trajectory prediction module, a frequency division module and a telescope guidance module;

[0027] The trajectory prediction module obtains the predicted trajectory of the target based on the target position obtained by the guidance source and sends it to the frequency division module;

[0028] The timing system provides a trigger signal carrying time information to the frequency division module according to the guidance frequency;

[0029] The frequency division module obtains the predicted position of the target on the predicted trajectory according to the trigger signal and the time information, and sends the predicted position of the target to the telescope guidance module;

[0030] The telescope guidance module generates guidance instructions according to the predicted target position, and sends guidance instructions to the telescope according to the guidance frequency to guide the telescope.

[0031] Preferably, the main control system further includes a guidance data receiving module, which receives the target position and converts the target position into a target position in a horizontal coordinate system, and the trajectory prediction module obtains the predicted trajectory of the target based on the target position in the horizontal coordinate system.

[0032] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0033] The guidance method and guidance system provided by the present invention obtain the predicted trajectory of the target by a trajectory prediction module, and the timing system sends a trigger signal carrying time information according to the guidance frequency of the telescope. The frequency division module combines the predicted trajectory, the time information and the trigger signal to obtain the predicted position of the target on the predicted trajectory to guide the telescope. The guidance method can independently select the frequency of sending the predicted position of the target to the telescope without considering the guidance frequency of the guidance source. When the guidance frequency of the guidance source is low or a small-field-of-view telescope is guided, the low-frequency guidance source data can be converted into high-frequency guidance data, which greatly reduces the jitter amplitude of the target in the field of view and reduces the probability of the target leaving the field of view, thereby improving the accuracy of the target predicted position data of the guiding telescope, greatly reducing the guidance error, and facilitating the smooth progress of relevant target observation experiments. The guidance method is applicable to different guidance sources and telescopes, and the optimization effect is particularly obvious under the conditions of a low-frequency guidance source and a small-field-of-view telescope.

[0034] When the moving target has a large acceleration or a certain acceleration change rate, when the guiding method of the present invention is applied to guide the telescope, the target still stably appears in the small field of view imaging system, and the guiding method is still applicable. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a boot flow chart of a boot method according to an embodiment of the present invention;

[0036] Figure 2 is a structural framework diagram of a guidance system provided according to an embodiment of the present invention;

[0037] Figure 3 is a curve diagram of azimuth data acquired by a guidance source provided in an embodiment of the present invention;

[0038] Figure 4 is a comparison diagram of azimuth guidance errors provided according to an embodiment of the present invention;

[0039] Figure 5 is a curve diagram of pitch angle data obtained by a guidance source provided by an embodiment of the present invention;

[0040] Figure 6 3 is a comparison diagram of pitch angle guidance errors provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0041] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same modules are represented by the same reference numerals. In the case of the same reference numerals, their names and functions are also the same. Therefore, the detailed description thereof will not be repeated.

[0042] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0043] like Figure 1 As shown, an embodiment of the present invention provides a telescope guidance method based on trajectory prediction, comprising:

[0044] S1: The guidance source in the embodiment of the present invention is a low-frequency guidance source, and the guidance frequency of the guidance source is 1Hz. The remote guidance source obtains the target position of the tracked target in a certain coordinate system in real time, and sends the target position to the local at a frequency of 1Hz. The target position includes the azimuth and elevation angle of the target obtained by the guidance source. Normally, the guidance data is obtained according to the target position obtained by the guidance source, and the telescope is directly guided to rotate to point to the target. If the guidance frequency of the guidance source to obtain the target position is 1Hz, the guidance data is sent to the telescope once per second, and the telescope rotates once per second to track the target. The frequency of 1Hz is too low, resulting in too low action frequency of the telescope tracking the target, and the target shakes and disappears in the field of view of the telescope, which is not conducive to observing and tracking the target. When the telescope is a small field telescope, the target shakes and disappears more frequently.

[0045] In the embodiment of the present invention, the time for the guiding source to obtain the target in real time is expressed as , at time The target position obtained is expressed as , represents the azimuth of the target position, represents the pitch angle at the target position, where Indicates the time The sequence number of the corresponding target location.

[0046] S2: Guide the source to continuously acquire a series of target positions , according to time Target location and in The target position obtained by the guidance source at adjacent historical times predicts the target's predicted trajectory and generates an equation. The predicted trajectory can show the movement trend of the target in the future time, including the target in the future time. Time to The predicted trajectory of the target's movement trend between time periods. The future time refers to the time period between The unreached time after the time. Target position in time The target position corresponding to the three adjacent historical times is used to obtain the predicted trajectory of the target. The target position corresponding to the three adjacent historical times is Target location for time acquisition , Target location of time acquisition and Target location of time acquisition .

[0047] The embodiment of the present invention is used Represents the target's predicted position on the predicted trajectory. Since the trajectory prediction methods for azimuth and elevation are the same, the predicted equation It can represent the azimuth angle or the pitch angle. Expressed as time The cubic function can get the prediction effect that meets the demand. Here, time is the horizontal coordinate of the predicted trajectory. When guiding the telescope, it is necessary to obtain the corresponding coordinate point on the predicted trajectory according to the target time. This coordinate point is the time for guiding the telescope. The corresponding target predicted position, the time It is given by the guidance system according to the telescope guidance requirements. After obtaining the predicted trajectory of the target, the equation of the predicted trajectory is generated:

[0048] ;

[0049] in, Indicates the time corresponding to the target predicted position, , , and They all represent the coefficients of the equation.

[0050] After generating the equation for the predicted trajectory, the coefficients of the equation are solved by the least squares normal equation , , and :

[0051] ;

[0052] in, , , , Indicates the target location The previous target position of Indicates the target location Previous target location, and so on.

[0053] Typically, some boot sources do not include time in their boot protocols. , need to calculate:

[0054] ;

[0055] in, Indicates the local receiving target location time, represents the average network delay, The value of can be measured by using existing relevant network tools. Treat it as a predetermined system error caused by the network connection. After solving the coefficients of the equation for predicting the trajectory, the final expression of the equation can be determined.

[0056] S3: When the guidance source's guidance frequency is 1Hz, it is a low-frequency guidance. Because the guidance source's guidance frequency is too low, the target will shake or disappear frequently in the telescope's field of view. Therefore, when the telescope is finally guided, the guidance frequency needs to be increased. Set the telescope's guidance frequency according to the guidance requirements. Usually, the telescope's guidance frequency is 50Hz or 100Hz.

[0057] After obtaining the equation of the target's predicted trajectory, the target is predicted based on the equation according to the set telescope guidance frequency. Time to The target predicted position required for the final guidance of the telescope is calculated on the curve between time. For example, if the guidance frequency of the telescope is set to 50Hz, it can be known from the guidance frequency of the guidance source that Time to If the time interval is 1 second, you need to Time to The coordinate point on the curve is calculated every 20 milliseconds as the target predicted position for guiding the telescope.

[0058] S4: Based on the target predicted position obtained by the above calculation, the telescope is guided to track the target. After the above process, the guidance data obtained by the guidance source at 1Hz can be converted into 50Hz or 100Hz guidance data for the final guidance telescope, realizing the function of upscaling the guidance data. The up-converted guidance data greatly reduces the situation where the target jitters in the field of view or repeatedly leaves the field of view, thereby improving the guidance accuracy.

[0059] To implement the above boot method, Figure 2 As shown, an embodiment of the present invention further provides a guidance system, including a remote guidance source and a local main control system, a timing system and a guided telescope with observation capability. The remote guidance source can be an optoelectronic system with capture capability or a guidance system with a known target motion trajectory.

[0060] The main control system is a main control computer, which includes a guidance data receiving module, a trajectory prediction module, a frequency division module and a telescope guidance module. The guidance source is connected to the guidance data receiving module of the main control system through the network, the guidance data receiving module is connected to the trajectory prediction module, the trajectory prediction module is connected to the frequency division module, the frequency division module is connected to the telescope guidance module, the telescope guidance module is connected to the guided telescope through the serial port, and the timing system is connected to the frequency division module through the serial port.

[0061] After the guidance source acquires a series of target positions in real time at a guidance frequency of 1 Hz, the target positions are sent to the guidance data receiving module. After receiving the target position data, the guidance data receiving module converts it into azimuth and pitch angles in the horizontal coordinate system, and sends the converted target positions to the trajectory prediction module. The sending frequency of the converted target positions is the same as the guidance frequency of the guidance source, which is 1 Hz.

[0062] The trajectory prediction module receives the converted target positions one by one, obtains the predicted trajectory of the target according to the target positions, and generates an equation for the predicted trajectory. In the embodiment of the present invention, the most recently received converted target position and the first three target positions adjacent to the most recently received converted target position are used to obtain the predicted trajectory of the target. After obtaining the predicted trajectory of the target, the equation for the predicted trajectory is sent to the frequency division module.

[0063] The guiding frequency of the guiding source is too low. When the telescope is finally guided, the guiding frequency of the telescope needs to be changed. When the guiding source is a low-frequency guiding source, the guiding frequency of the telescope is usually set higher than the guiding frequency of the guiding source. In the embodiment of the present invention, the guiding frequency of the telescope is set to 50 Hz or 100 Hz.

[0064] After the frequency division module receives the equation of the predicted trajectory, it needs to calculate the predicted target position through the equation according to the guidance frequency required for the final guidance of the telescope. Usually, the guidance frequency of the telescope is 50Hz or 100Hz. The embodiment of the present invention takes 50Hz as an example to illustrate the role of the frequency division module. After setting the guidance frequency of the telescope to 50Hz, the timing system sends a trigger signal carrying time information to the frequency division module at a frequency of 50Hz, that is, it sends a trigger signal and the time information contained in the trigger signal to the frequency division module every 20 milliseconds. The time information mentioned here is the above-mentioned time , which refers to the time corresponding to the target predicted position. When obtaining the target predicted position on the curve of the predicted trajectory, the time Corresponding to a certain time point of the horizontal coordinate of the predicted trajectory. After receiving the equation of the predicted trajectory, the frequency division module obtains the predicted target position on the equation of the predicted trajectory according to the trigger signal and time information sent by the timing system. The guidance source obtains the target position at a frequency of 1Hz. After the above trajectory prediction and calculation by the frequency division module, the predicted target position with a frequency of 50Hz can be obtained, and it is used to guide the telescope to realize the role of converting low-frequency guidance source data into high-frequency guidance data, greatly reducing the jitter amplitude of the target in the field of view, and reducing the probability of the target leaving the field of view.

[0065] After the frequency division module calculates the predicted target position, it sends the predicted target position to the telescope guidance module. The telescope guidance module generates a guidance instruction based on the received predicted target position and sends it to the guided telescope through the serial port to achieve telescope guidance. The frequency of the guidance instruction sent by the telescope guidance module is the same as the frequency of the trigger signal sent by the timing system, both of which are the guidance frequencies of the telescope.

[0066] To ensure that the guiding method of the present invention is effective, the following verification experiments were also conducted:

[0067] The azimuth and elevation angle data obtained by the guidance source are generated as follows Figure 3 and Figure 4 The conventional linear difference method and the method of the present invention are used to process the guidance data obtained by the guidance source and guide the telescope to track the target, and the following is obtained: Figure 4 and Figure 5 From the error comparison curve shown, it can be seen that when the change rate of the original guidance data is large, the linear difference method has a large error, and the error of the guidance method of the present invention is significantly smaller than that of the linear difference method as a whole. In the external guidance observation work, the target is not easy to leave the field of view when the method of the present invention is used to guide the telescope, and the jitter amplitude of the target in the field of view is smaller.

[0068] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. Those skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

[0069] The above specific implementations of the present invention do not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A telescope guidance method based on trajectory prediction, characterized in that: include: S1: Acquire the target through the guidance source according to the target acquisition frequency Target position corresponding to time , Indicates the time The serial number of the corresponding target location; S2: Based on the target position and in The target position is obtained by the guidance source at adjacent historical times, and the Time to The predicted trajectory of the target between time periods; the equation for the predicted trajectory is: ； in, represents the predicted position of the target on the predicted trajectory, Indicates the time corresponding to the target predicted position, , , and All represent the coefficients of the equation; The coefficients of the equation , , and The calculation method is: ； in, , , S3: Set the guidance frequency of the telescope, and obtain the predicted trajectory according to the guidance frequency of the telescope. Time to The predicted position of the target between times; S4: Transmitting the predicted target position to the telescope at a guiding frequency to guide the telescope to track the target.

2. The telescope guidance method based on trajectory prediction according to claim 1, characterized in that: In S2, The value is 3.

3. The telescope guidance method based on trajectory prediction according to claim 1, characterized in that: The telescope's guidance frequency is 50Hz or 100Hz.

4. A telescope guidance system based on trajectory prediction, characterized in that: Based on the telescope guidance method based on trajectory prediction according to any one of claims 1 to 3, the guidance system includes a guidance source, a main control system and a timing system, and the main control system includes a trajectory prediction module, a frequency division module and a telescope guidance module; The trajectory prediction module obtains the predicted trajectory of the target according to the target position obtained by the guidance source, and sends it to the frequency division module; The timing system provides a trigger signal carrying time information to the frequency division module according to the guide frequency; The frequency division module obtains the target predicted position on the predicted trajectory according to the trigger signal and the time information, and sends the target predicted position to the telescope guidance module; The telescope guidance module generates a guidance instruction according to the predicted target position, and sends the guidance instruction to the telescope according to the guidance frequency to guide the telescope.

5. The telescope guidance system based on trajectory prediction according to claim 4, characterized in that: The main control system further includes a guidance data receiving module, which receives the target position and converts the target position into a target position in a horizontal coordinate system. The trajectory prediction module obtains a predicted trajectory of the target according to the target position in the horizontal coordinate system.

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