Method for obtaining a scale factor of a gyroscopic speed sensor in an aerial camera
By controlling the sinusoidal motion of the internal and external drive system frames in the aerial camera and using the angle data of the gyro velocimeter sensor for online calibration, the problem of cumbersome scaling factor correction of the gyro velocimeter sensor is solved, the image clarity is improved and the maintenance cycle is extended.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- TIANJIN JINHANG INST OF TECH PHYSICS
- Filing Date
- 2023-09-27
- Publication Date
- 2026-07-10
AI Technical Summary
In the existing technology, the scaling factor correction method of the gyro velocity sensor of aerial camera is cumbersome and relies on precise measurement, resulting in large errors in the measurement of the imager rotation speed, which affects the image clarity.
By controlling the sinusoidal motion of the internal and external drive system frame of the aerial camera, and using the angle data and angular velocity of the gyro velocity sensor, online calibration is performed to obtain the scaling factor, eliminate data drift, and achieve simple correction.
It improves image clarity, extends the maintenance cycle of aerial cameras, and avoids cumbersome disassembly and precise measurement operations.
Smart Images
Figure CN117053837B_ABST
Abstract
Description
Technical Field
[0001] This application generally relates to the field of aerial optoelectronic reconnaissance technology, and in particular to a method for obtaining the scaling factor of a gyro velocity sensor in an aerial camera. Background Technology
[0002] Aerial cameras, as airborne image acquisition devices, have wide applications in aerial reconnaissance and surveying. For example... Figure 2 As shown, aerial cameras typically have two drive systems (usually an external drive system mounted on the mounting base and an internal drive system connected within the external drive system) with their axes extending perpendicularly to each other and parallel to the camera mounting surface. These drive systems propel the imager to rotate in different directions, enabling the search and tracking of ground targets. To ensure clearer images acquired by the high-speed rotating imager, it is necessary to acquire the imager's rotational speed data in real time and use this data to compensate for the imager's imaging and exposure. Inside the aerial camera, the device used to acquire this rotational speed data is a gyro velocimeter sensor, which is connected to the imager and rotates synchronously with it. The gyro velocimetry sensor has three internal coordinate axes: x, y, and z. When installed, the y-axis is parallel to the internal drive system's axis; and when the internal drive system is at zero position, the x-axis is parallel to the external drive system's axis. As it rotates, it acquires motion data relative to these three axes. This motion data is then converted to the external and internal drive system axes and multiplied by an internal scaling factor to obtain the gyro velocimetry sensor's rotational speed around the external and internal drive system axes, which are also the imager's rotational speeds. The composite rotational speed is used to compensate for the imager's movement. In practice, this scaling factor deviates over time with the aerial camera's usage, causing errors in the gyro velocimetry sensor's measurement of the imager's rotational speed and resulting in a blurred image. Therefore, the gyro velocimetry sensor's internal scaling factor needs to be corrected periodically. Existing calibration methods typically involve detaching the gyro velocimetry sensor from the aerial camera and placing it on a single-axis machine. The single-axis machine, or other data testing device, is then used to obtain the scaling factors for each axis of the gyro velocimetry sensor, which are then converted to the axes of the external and internal drive systems. The drawbacks of this method are its cumbersome operation, reliance on precise measurement conditions, and significant error when the current and actual values of the scaling factors deviate considerably. These issues are problems that urgently need to be addressed in this field. Summary of the Invention
[0003] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a method for obtaining the scaling factor of the gyro velocity sensor in an aerial camera that is relatively simple to operate and does not depend on precise measurement conditions.
[0004] The specific technical solution is as follows:
[0005] The internal drive system frame and the external drive system frame of the aerial camera are locked in different relative positions, and the external drive system frame is controlled to rotate in a first set manner. During each test, the gyroscope speed sensor measures the first motion data on its x-axis. In the first set manner, the period of the rotating object is the first period value and the amplitude is the first amplitude value.
[0006] Based on the angle between the x-axis of the gyroscope speed sensor and the rotation axis of the external drive system during each test, the first motion data is converted onto the rotation axis of the external drive system to obtain the second motion data.
[0007] Based on the second motion data, obtain the first angle values through which the gyroscope velocity sensor rotates relative to the x-axis of the gyroscope velocity sensor during each test.
[0008] Based on each of the first angle value, the first period value, and the first amplitude value, obtain the first scaling factor used by the gyroscope velocimetry sensor when measuring the rotational speed of the imager around the outer axis;
[0009] The external drive system frame is controlled to rotate in a second preset mode, and the third motion data measured by the gyroscope speed sensor on its y-axis during each test are obtained. In the second preset mode, the period of the rotating object is the second period value and the amplitude is the second amplitude value.
[0010] Based on the third motion data, obtain the second angle values through which the gyroscope velocity sensor rotates relative to the y-axis of the gyroscope velocity sensor during each test.
[0011] The second scaling factor is obtained when the gyroscope velocimetry sensor measures the rotational speed of the imager around its inner axis, based on the second angle value, the second period value, and the second amplitude value.
[0012] As a further limitation of this application, the control external drive system frame rotates in a first preset manner, specifically: the external drive system frame is made to perform a sinusoidal motion with a period of a first period value and an amplitude of a first amplitude value;
[0013] The control external drive system frame rotates in a second preset manner, specifically by causing the external drive system frame to perform a sinusoidal motion with a period of the second period value and an amplitude of the second amplitude value.
[0014] As a further limitation of this application, before obtaining the first angle values through which the gyroscope velocity sensor rotates relative to the x-axis of the gyroscope velocity sensor during each test based on the second motion data, the method further includes: eliminating the drift amount of the second motion data;
[0015] Before acquiring the second angle values through which the gyroscope velocity sensor rotates relative to the y-axis of the gyroscope velocity sensor during each test based on the third motion data, the method further includes: eliminating the drift amount of the third motion data.
[0016] As a further limitation of this application, the conversion of each of the first motion data onto the external drive system shaft to obtain each of the second motion data is based on the following formula:
[0017] i = 0, 1, 2...M, where i is the number of tests; A i ω is the angle between the x-axis of the gyroscope speed sensor and the rotation axis of the external drive system; xi For the first motion data; ω' xi This refers to the second motion data.
[0018] As a further limitation of this application, the amount of drift eliminated from the second motion data is based on the following formula:
[0019]
[0020] , where ω'' xi (k) represents the second motion data after eliminating the drift;
[0021] The drift elimination amount for the third motion data is based on the following formula:
[0022]
[0023] , where ω yi For the third motion data, ω' yi The third motion data after eliminating the drift amount.
[0024] As a further limitation of this application, the step of obtaining the first angle values through which the gyroscope velocity sensor rotates relative to the x-axis of the gyroscope velocity sensor during each test based on the second motion data is according to the following formula:
[0025]
[0026] , where T1 is the sampling period of each test in the process of obtaining the first scaling factor;
[0027] The second angle values through which the gyroscope velocity sensor rotates relative to the y-axis during each test are obtained based on the third motion data, according to the following formula:
[0028]
[0029] , where T2 is the sampling period of each test during the process of obtaining the second scaling factor.
[0030] As a further limitation of this application, the first scaling factor used when obtaining the rotational speed of the imager around its outer axis by the gyroscope velocimetry sensor based on each of the first angle value, the first period value, and the first amplitude value is based on the following formula:
[0031]
[0032] , where L xo This is the first initial scaling factor in the x-direction of the current gyro velocity sensor;
[0033] The second scaling factor used when obtaining the rotational speed of the imager around its inner axis by the gyroscope velocimetry sensor based on each of the second angle values, the second period value, and the second amplitude value is based on the following formula:
[0034]
[0035] , where L yo This is the second initial scaling factor in the y-direction of the current gyro velocity sensor.
[0036] The beneficial effects of this application are:
[0037] In this scheme, the first scaling factor of the external drive system axis of the gyroscope velocimetry sensor is calibrated: the internal drive system frame of the aerial camera is fixed at several angle values, and the external drive system frame is periodically moved at a specified angular velocity, collecting the angular motion data of the external drive system frame. The angular velocity of the corresponding gyroscope sensitive axis is projected onto the direction of the external drive system frame, and then integrated. After eliminating the drift of the integrated value, the first scaling factor in that direction is determined based on its amplitude ratio with the angle sensor data of the external drive system frame, thus achieving the calibration of the sensitive axis of the gyroscope external drive system frame. Then, the second scaling factor of the internal drive system axis of the gyroscope velocimetry sensor is calibrated: the internal drive system frame of the aerial camera is periodically moved at a specified angular velocity, and the angular motion sensor data of the internal drive system frame is collected. The corresponding angular velocity of the gyroscope sensitive axis is integrated, and after eliminating the drift of the integrated value, the second scaling factor in that direction is determined based on its amplitude ratio with the angle sensor data of the internal drive system frame, thus achieving online calibration of the sensitive axis of the gyroscope internal drive system frame. This method utilizes the aerial camera's own angle sensor data and calibrates the gyroscope scaling factor, which can effectively improve the clarity of scanning images under long-term working conditions and extend the maintenance cycle of the aerial camera. Attached Figure Description
[0038] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:
[0039] Figure 1 A flowchart illustrating the steps of a method for obtaining the scaling factor of a gyro velocity sensor in an aerial camera, as provided in an embodiment of this application.
[0040] Figure 2 for Figure 1 A schematic diagram of the internal structure of an aerial camera;
[0041] The diagram is labeled as follows: 1, internal drive system frame; 2, external drive system frame; 3, gyroscope speed sensor; O2, external drive system shaft; 4, imager; O1, internal drive system shaft. Detailed Implementation
[0042] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.
[0043] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.
[0044] Please refer to Figure 1 and Figure 2 The method for obtaining the scaling factor of a gyro velocity sensor in an aerial camera, as provided in this embodiment, includes the following steps:
[0045] S1: Lock the internal drive system frame 1 and the external drive system frame 2 of the aerial camera to different relative positions, and control the external drive system frame 2 to rotate in a first set manner, and acquire the first motion data measured by the gyroscope speed sensor 3 on its x-axis during each test, wherein, under the first set manner, the period of the rotating object is the first period value and the amplitude is the first amplitude value.
[0046] S2: Based on the angle between the 3x axis of the gyroscope speed sensor and the external drive system rotation axis O2 during each test, the first motion data is converted onto the external drive system rotation axis O2 to obtain the second motion data.
[0047] S3: Based on the second motion data, obtain the first angle values through which the gyroscope speed sensor 3 rotates relative to the x-axis of the gyroscope speed sensor 3 during each test.
[0048] S4: Based on each of the first angle value, first period value, and first amplitude value, obtain the first scaling factor used by the gyroscope speed sensor 3 when measuring the rotational speed of the imager 4 around the external drive system shaft O2;
[0049] S5: Control the external drive system frame 2 to rotate in a second preset mode, and acquire the third motion data measured by the gyroscope speed sensor 3 on its y-axis during each test, wherein, under the second preset mode, the period of the rotating object is the second period value and the amplitude is the second amplitude value;
[0050] S6: Based on the third motion data, obtain the second angle values through which the gyroscope speed sensor 3 rotates relative to the y-axis during each test.
[0051] S7: Based on each of the second angle value, second period value, and second amplitude value, obtain the second proportional factor used by the gyroscope speed sensor 3 when measuring the rotational speed of the imager 4 around the inner drive system shaft O1.
[0052] In this scheme, the first scaling factor of the external drive system axis O2 of the gyroscope velocimetry sensor is calibrated first: the internal drive system frame 1 of the aerial camera is fixed at several angle values, and the external drive system frame 2 of the aerial camera is made to move periodically at a specified angular velocity, and the motion angle data of the external drive system frame 2 is collected. The angular velocity of the corresponding gyroscope sensitive axis is projected onto the direction of the external drive system frame 2, and then integrated. After eliminating the drift of the integrated value, the first scaling factor in that direction is determined according to the amplitude ratio of the integrated value with the angle sensor data of the external drive system frame 2, thus realizing the calibration of the sensitive axis of the gyroscope external drive system frame 2. Then, the second scaling factor of the internal drive system axis O1 of the gyroscope velocimetry sensor is calibrated: the internal drive system frame 1 of the aerial camera is made to move periodically at a specified angular velocity, and the motion angle sensor data of the internal drive system frame 1 is collected. The corresponding gyroscope sensitive axis angle is integrated. After eliminating the drift of the integrated value, the second scaling factor in that direction is determined according to the amplitude ratio of the integrated value with the angle sensor data of the internal drive system frame 1, thus realizing the online calibration of the sensitive axis of the gyroscope internal drive system frame 1. This method utilizes the aerial camera's own angle sensor data and calibrates the gyroscope scaling factor, which can effectively improve the clarity of scanning images under long-term working conditions and extend the maintenance cycle of the aerial camera.
[0053] The control external drive system frame 2 rotates in a first preset manner, specifically by causing the external drive system frame 2 to perform a sinusoidal motion with a period of a first period value and an amplitude of a first amplitude value;
[0054] The control external drive system frame 2 rotates in a second preset manner, specifically by causing the external drive system frame 2 to perform a sinusoidal motion with a period of the second period value and an amplitude of the second amplitude value.
[0055] Before acquiring the first angle values through which the gyroscope speed sensor 3 rotates relative to the x-axis of the gyroscope speed sensor 3 during each test based on the second motion data, the method further includes: eliminating the drift amount of the second motion data.
[0056] Before obtaining the second angle values through which the gyroscope velocity sensor 3 rotates relative to the y-axis during each test based on the third motion data, the method further includes: eliminating the drift amount from the third motion data.
[0057] The first motion data is converted onto the external drive system shaft O2 to obtain the second motion data, according to the following formula:
[0058] i = 0, 1, 2...M, where i is the number of tests; A i ω is the angle between the 3x axis of the gyroscope speed sensor and the O2 axis of the external drive system; xi The first motion data; ω' xi This refers to the second motion data.
[0059] The drift elimination of the second motion data is based on the following formula:
[0060]
[0061] , where ω'' xi k is the second motion data after eliminating the drift amount;
[0062] The drift elimination amount for the third motion data is based on the following formula:
[0063]
[0064] , where ω yi For the third motion data, ω' yi The third motion data after eliminating the drift amount.
[0065] The first angle values through which the gyroscope velocity sensor 3 rotates relative to the x-axis of the gyroscope velocity sensor 3 during each test are obtained based on the second motion data, according to the following formula:
[0066]
[0067] , where T1 is the sampling period of each test in the process of obtaining the first scaling factor;
[0068] The second angle values through which the gyroscope velocity sensor 3 rotates relative to the y-axis during each test are obtained based on the third motion data, according to the following formula:
[0069]
[0070] , where T2 is the sampling period of each test during the process of obtaining the second scaling factor.
[0071] The first scaling factor used when obtaining the rotational speed of the gyroscope velocimetry sensor 3 to measure the rotational speed of the imager 4 around the external drive system shaft O2 based on the first angle value, the first period value, and the first amplitude value is according to the following formula:
[0072]
[0073] , where L xo This is the first initial scaling factor in the x-direction of the current gyro velocity sensor 3;
[0074] The second proportionality factor used when obtaining the rotational speed of the gyroscope velocimetry sensor 3 to measure the rotational speed of the imager 4 around the inner drive system shaft O1 based on the second angle value, the second period value, and the second amplitude value is according to the following formula:
[0075]
[0076] , where L yo This is the second initial scaling factor in the y-direction of the current gyro velocity sensor 3.
[0077] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.
Claims
1. A method for obtaining the scaling factor of a gyro velocity sensor in an aerial camera, characterized in that, Includes the following steps: The internal drive system frame (1) and the external drive system frame (2) of the aerial camera are locked in different relative positions, and the external drive system frame (2) is controlled to rotate in a first set mode. During each test, the gyroscope speed sensor (3) measures each first motion data on its x-axis. In the first set mode, the period of the rotating object is the first period value and the amplitude is the first amplitude value. Based on the angle between the x-axis of the gyroscope speed sensor (3) and the external drive system rotation axis (O2) during each test, the first motion data is converted onto the external drive system rotation axis (O2) to obtain the second motion data. Based on the second motion data, obtain the first angle values through which the gyroscope speed sensor (3) rotates relative to the x-axis during each test; The first scaling factor used by the gyroscope speed sensor (3) to measure the rotational speed of the imager (4) around the external drive system shaft (O2) is obtained based on each of the first angle value, first period value and first amplitude value. Control the external drive system frame (2) to rotate in a second setting mode, and acquire the third motion data measured by the gyroscope speed sensor (3) on its y-axis during each test, wherein, under the second setting mode, the period of the rotating object is the second period value and the amplitude is the second amplitude value; Based on the third motion data, the second angle values of the gyroscope speed sensor (3) relative to the y-axis of the gyroscope speed sensor (3) are obtained during each test. According to each of the second angle values, second period values, and second amplitude values, the second proportional factor used when the gyroscope speed sensor (3) measures the rotational speed of the imager (4) around the inner drive system shaft (O1) is obtained; the control of the outer drive system frame (2) to rotate in a first set manner is specifically: the outer drive system frame (2) is made to perform a sinusoidal motion with a period of the first period value and an amplitude of the first amplitude value; The control external drive system frame (2) rotates in a second preset manner, specifically: the external drive system frame (2) is made to perform a sinusoidal motion with a period of the second period value and an amplitude of the second amplitude value; the first motion data is converted onto the external drive system rotating shaft (O2) to obtain the second motion data, according to the following formula: i = 0, 1, 2...M, where i is the number of tests; A i ω is the angle between the x-axis of the gyroscope speed sensor (3) and the rotating shaft (O2) of the external drive system; xi The first motion data; ω' xi This refers to the second motion data.
2. The method for obtaining the scaling factor of a gyro velocity sensor in an aerial camera according to claim 1, characterized in that, Before obtaining the first angle values through which the gyroscope speed sensor (3) rotates relative to the x-axis of the gyroscope speed sensor (3) during each test based on the second motion data, the method further includes: eliminating the drift amount of the second motion data; Before obtaining the second angle values through which the gyroscope velocity sensor (3) rotates relative to the y-axis of the gyroscope velocity sensor (3) during each test based on the third motion data, the method further includes: eliminating the drift amount of the third motion data.
3. The method for obtaining the scaling factor of a gyro velocity sensor in an aerial camera according to claim 1, characterized in that, The drift elimination of the second motion data is based on the following formula: ， Where ω'' xi (k) represents the second motion data after eliminating the drift; The drift elimination amount for the third motion data is based on the following formula: ， Where, ω yi For the third motion data, ω' yi The third motion data after eliminating the drift amount.
4. The method for obtaining the scaling factor of a gyro velocity sensor in an aerial camera according to claim 3, characterized in that, The method involves obtaining the first angle values through which the gyroscope speed sensor (3) rotates relative to the x-axis during each test based on the second motion data, according to the following formula: ， Where T1 is the sampling period of each test in the process of obtaining the first scaling factor; The second angle values through which the gyroscope velocity sensor (3) rotates relative to the y-axis during each test are obtained based on the third motion data, according to the following formula: ， Where T2 is the sampling period of each test during the process of obtaining the second scaling factor.
5. The method for obtaining the scaling factor of a gyro velocity sensor in an aerial camera according to claim 4, characterized in that, The first scaling factor used when obtaining the rotational speed of the gyroscope velocimetry sensor (3) measuring the imager (4) around the external drive system shaft (O2) based on each of the first angle value, first period value, and first amplitude value is based on the following formula: ， Among them, L xo This is the first initial scaling factor in the x-direction of the current gyro velocity sensor (3); The second scaling factor used when obtaining the rotational speed of the gyroscope velocimetry sensor (3) measuring the rotational speed of the imager (4) around the inner drive system shaft (O1) based on each of the second angle values, second period values, and second amplitude values is based on the following formula: ， Among them, L yo It is the second initial scaling factor in the y-direction of the current gyroscope speed sensor (3).