A driving circuit supporting multi-degree-of-freedom image shift compensation function

Abstract

The application belongs to the technical field of aerospace, and provides a driving circuit supporting multi-degree-of-freedom image motion compensation function, which comprises a camera controller, a multi-degree-of-freedom image motion compensation timing generator, a vertical driving circuit, a two-dimensional direction charge transfer area array CCD detector, a horizontal driving circuit, a front-end signal processing circuit and an interface circuit. The camera controller is connected with the multi-degree-of-freedom image motion compensation timing generator. The multi-degree-of-freedom image motion compensation timing generator is connected with the vertical driving circuit, the two-dimensional direction charge transfer area array CCD detector and the horizontal driving circuit respectively. The vertical driving circuit and the horizontal driving circuit are further connected with the two-dimensional direction charge transfer area array CCD detector. The two-dimensional direction charge transfer area array CCD detector is connected with the front-end signal processing circuit. The front-end signal processing circuit is connected with the interface circuit. The application can realize on-chip compensation of roll, pitch, yaw and multi-degree-of-freedom dynamic motion without moving parts.

Description

Technical Field

[0001] This application relates to the field of aerospace technology, specifically to a drive circuit that supports multi-degree-of-freedom image shift compensation. Background Technology

[0002] During reconnaissance operations, reconnaissance aircraft need to fly at high speed and low altitude to evade enemy radar surveillance. Low-altitude, high-speed flight significantly improves the aircraft's battlefield survivability and deep reconnaissance and surveillance capabilities. However, this results in severe image shift on the target surface, leading to blurred aerial images. Image shift greatly affects camera image quality, significantly reducing the resolution of aerial photographs. When image shift exists, the captured target outline is unclear, and a transition zone of varying sizes exists between the target and the surrounding background. This transition zone expands with increasing image shift, and when it reaches a certain extent, it can cause the images of adjacent targets to overlap or even become indistinguishable. In addition to forward flight, reconnaissance aircraft adjust their flight attitude according to tactical requirements, such as pitch, yaw, roll, and complex multi-degree-of-freedom motions. Different flight attitudes leave different image shift trajectories on the target surface. Therefore, compensating for the attitude angles generated by the aircraft's flight attitude is of great significance. Domestic and international scholars have already conducted relevant research on the impact of aircraft flight attitude on aerial camera imaging performance and on aircraft flight attitude compensation. Due to the special purpose of aerial cameras, relevant data on platform attitude image shift compensation in foreign research are kept strictly confidential, and related literature is limited.

[0003] Current image shift compensation methods mainly focus on three aspects: First, using electronic means to develop CCD devices with Time Delay and Integration (TDI) functionality, and employing charge transfer driving technology to control the charge transfer speed of the CCD within the integration time for specific CCD devices, thus achieving image shift compensation. Second, researching image processing algorithms to achieve sharpening of blurred images or correction of image rotation through post-processing, but this results in the loss of image information. Third, employing motion control technology to compensate for image shift caused by motion imaging by controlling inertial stabilization platforms, scanning mirrors, and fast-reflecting mirrors. These methods require extremely high structural accuracy, reliability, and stability.

[0004] Domestic and international aerial camera compensation methods utilize mechanical, optical, image-based, and electronic image shift compensation techniques. Mechanical and optical compensation systems significantly increase the weight and size of aerial cameras; image-based image shift compensation is a post-processing method and cannot provide real-time compensation. Currently reported electronic image shift compensation methods mainly utilize TDICCD for forward image shift compensation and stepped block compensation for anomalous image shift in aerial photography. However, no good solution has been provided for the multi-degree-of-freedom motion of aerial cameras, including roll, pitch, yaw, and more complex motions. This severely restricts the development of image shift compensation technology and high-end CCDs (on-chip CCDs supporting roll, pitch, yaw, and complex multi-degree-of-freedom dynamic motion compensation). Summary of the Invention

[0005] In view of this, it is necessary to provide a drive circuit that supports multi-degree-of-freedom image shift compensation function to address the shortcomings of the existing technology, so as to realize on-chip compensation of roll, pitch, yaw and multi-degree-of-freedom dynamic motion without moving the components, and reduce the quality, size, power consumption and cost of the imaging system.

[0006] To solve the above problems, this application adopts the following technical solution:

[0007] A driving circuit supporting multi-degree-of-freedom image shift compensation includes: a camera controller, a multi-degree-of-freedom image shift compensation timing generator, a vertical driving circuit, a two-dimensional directional charge transfer array CCD detector, a horizontal driving circuit, a front-end signal processing circuit, and an interface circuit. The camera controller is connected to the multi-degree-of-freedom image shift compensation timing generator. The multi-degree-of-freedom image shift compensation timing generator is connected to the vertical driving circuit, the two-dimensional directional charge transfer array CCD detector, and the horizontal driving circuit. The vertical driving circuit and the horizontal driving circuit are also connected to the two-dimensional directional charge transfer array CCD detector. The two-dimensional directional charge transfer array CCD detector is connected to the front-end signal processing circuit, and the front-end signal processing circuit is connected to the interface circuit.

[0008] Furthermore, the multi-degree-of-freedom image shift compensation timing generator includes: a main timing generator, a vertical charge transfer bus interface module, a vertical direction image shift compensation timing control module, a vertical direction image shift timing generation module, a horizontal charge transfer bus interface module, a horizontal direction image shift compensation timing control module, and a horizontal direction image shift timing generation module.

[0009] The camera controller is connected to the vertical charge transfer bus interface module, the horizontal charge transfer bus interface module, and the main timing generation module. The horizontal charge transfer bus interface module is connected to the horizontal image shift compensation timing control module, which is connected to the horizontal image shift timing generation module. The vertical charge transfer bus interface module is connected to the vertical image shift compensation timing control module, which is connected to the vertical image shift timing generation module. The vertical image shift timing generation module is connected to the vertical drive circuit, and the horizontal image shift timing generation module is connected to the horizontal drive circuit.

[0010] Furthermore, the main timing generation module is used to generate the horizontal drive timing and vertical drive timing required when the aerial camera does not perform image shift compensation; the vertical charge transfer bus interface module is used to receive the vertical image shift compensation time interval information transmitted from the camera controller; the vertical image shift compensation timing control module is used to generate timing pulses according to the time interval information during exposure, and generate the trigger signal and timing switching signal required for vertical image shift compensation according to the vertical working state; the vertical image shift timing generation module generates the vertical image shift compensation drive timing based on the timing pulses; the horizontal charge transfer bus interface module is used to receive the horizontal image shift compensation time interval information transmitted from the camera controller; the horizontal image shift compensation timing control module is used to generate timing pulses according to the time interval information during exposure, and generate the trigger signal and timing switching signal required for horizontal image shift compensation according to the horizontal working state; the horizontal image shift timing generation module generates the horizontal image shift compensation drive timing based on the timing pulses.

[0011] Furthermore, the two-dimensional directional charge transfer array CCD detector is used to compensate for multi-degree-of-freedom image shifts in aerial cameras.

[0012] Furthermore, the two-dimensional directional charge transfer array CCD detector has pixels arranged in rows and columns. All pixels transmit pixel information at the same or different rates in the row and column directions. The driving circuit can control the charge to drive the charge to transfer along the row and column directions respectively.

[0013] Furthermore, the camera controller uses the received aircraft and detector information to generate task parameters for multi-degree-of-freedom image shift compensation of the aerial camera and sends the task parameters to the multi-degree-of-freedom image shift compensation timing generator.

[0014] Furthermore, the front-end signal processing circuit performs correlation double sampling, controllable gain amplification, dark level clamping compensation, and analog-to-digital conversion on the analog signal output by the two-dimensional directional charge transfer array CCD detector; the interface circuit is responsible for outputting the digital image signal generated by the analog-to-digital converter from the camera and providing an interface for communication with the host computer.

[0015] Furthermore, the camera controller is developed using a microcontroller, the multi-degree-of-freedom image shift compensation timing generator is developed using an FPGA, the two-dimensional directional charge transfer array CCD detector is a customized detector, the vertical drive circuit and the horizontal drive circuit are developed using dedicated chips, the front-end signal processing circuit is developed using dedicated chips, and the interface circuit is developed using dedicated chips.

[0016] The technical solution adopted in this application has the following effects:

[0017] The driving circuit supporting multi-degree-of-freedom image shift compensation in this application includes: a camera controller, a multi-degree-of-freedom image shift compensation timing generator, a vertical driving circuit, a two-dimensional directional charge transfer array CCD detector, a horizontal driving circuit, a front-end signal processing circuit, and an interface circuit. It can achieve on-chip compensation for roll, pitch, yaw, and multi-degree-of-freedom dynamic motion without moving the components, and can reduce the quality, size, power consumption, and cost of the imaging system. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the multi-degree-of-freedom motion image shift principle of an aerial camera and a schematic diagram of image shift on the target surface are provided for embodiments of this application;

[0020] Figure 2 This application provides a driving circuit that supports multi-degree-of-freedom image shift compensation.

[0021] Figure 3 This is a diagram illustrating the internal structure of a CCD detector supporting two-dimensional directional charge transfer array, as provided in an embodiment of this application. Detailed Implementation

[0022] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments.

[0024] Causes of multi-degree-of-freedom image shift in aviation:

[0025] During reconnaissance, reconnaissance aircraft need to fly at high speed and low altitude to evade enemy radar surveillance. Low-altitude, high-speed flight greatly improves the aircraft's battlefield survivability and deep reconnaissance and surveillance capabilities. However, this results in severe image shift on the target surface, causing blurred aerial images. The presence of image shift significantly affects camera image quality, noticeably reducing the resolution of aerial photographs. When image shift exists, the target outline is unclear, and there is a transition zone of varying sizes between the target and the surrounding background. This transition zone expands with increasing image shift, and when it reaches a certain extent, it can cause the images of adjacent targets to overlap or even become indistinguishable. In addition to forward flight, the flight attitude of reconnaissance aircraft is adjusted according to tactical and technical requirements, such as pitch, yaw, roll, and complex multi-degree-of-freedom movements. Corresponding to different flight attitudes, the images will leave different image shift trajectories on the target surface, such as... Figure 1 As shown.

[0026] Example 1

[0027] like Figure 2 As shown in the figure, this application embodiment provides a driving circuit supporting multi-degree-of-freedom image shift compensation function, including: a camera controller, a multi-degree-of-freedom image shift compensation timing generator, a vertical driving circuit, a two-dimensional directional charge transfer array CCD detector, a horizontal driving circuit, a front-end signal processing circuit, and an interface circuit. The camera controller is connected to the multi-degree-of-freedom image shift compensation timing generator. The multi-degree-of-freedom image shift compensation timing generator is connected to the vertical driving circuit, the two-dimensional directional charge transfer array CCD detector, and the horizontal driving circuit, respectively. The vertical driving circuit and the horizontal driving circuit are also connected to the two-dimensional directional charge transfer array CCD detector. The two-dimensional directional charge transfer array CCD detector is connected to the front-end signal processing circuit, and the front-end signal processing circuit is connected to the interface circuit.

[0028] The camera controller is used to send the received aircraft parameters, such as flight altitude, flight speed, pitch angle, yaw angle, roll angle, and detector parameters, such as focal length, CCD pixel size, and CCD phase number, to the multi-degree-of-freedom image shift compensation task parameters, such as the working mode, for the aerial camera, and to the multi-degree-of-freedom image shift compensation timing generator.

[0029] The multi-degree-of-freedom image shift compensation timing generator is used to generate the horizontal and vertical driving timing required for the two-dimensional directional charge transfer array CCD detector, generating the horizontal driving timing required for horizontal charge transfer and the vertical driving timing required for vertical charge transfer during multi-degree-of-freedom image shift compensation. The horizontal driving circuit is used to amplify and translate the received horizontal timing signal and the horizontal charge transfer driving timing to generate a driving level signal with sufficient voltage and current driving capability. During multi-degree-of-freedom image shift compensation, it drives the horizontal charge to move, compensating for the image shift component in the horizontal direction of the image plane. The vertical driving circuit is used to amplify and translate the received vertical timing signal and the vertical driving timing to generate a driving level signal with sufficient voltage and current driving capability. During multi-degree-of-freedom image shift compensation, it drives the vertical charge to transfer, compensating for the multi-degree-of-freedom image shift component in the vertical direction of the image plane.

[0030] Specifically, the multi-degree-of-freedom image shift compensation timing generator includes: a main timing generator, a vertical charge transfer bus interface module, a vertical image shift compensation timing control module, a vertical image shift timing generation module, a horizontal charge transfer bus interface module, a horizontal image shift compensation timing control module, and a horizontal image shift timing generation module; the camera controller is connected to the vertical charge transfer bus interface module, the horizontal charge transfer bus interface module, and the main timing generation module; the horizontal charge transfer bus interface module is connected to the horizontal image shift compensation timing control module; the horizontal image shift compensation timing control module is connected to the horizontal image shift timing generation module; the vertical charge transfer bus interface module is connected to the vertical image shift compensation timing control module; the vertical image shift compensation timing control module is connected to the vertical image shift timing generation module; the vertical image shift timing generation module is connected to the vertical drive circuit; and the horizontal image shift timing generation module is connected to the horizontal drive circuit.

[0031] It should be noted that the main timing generation module is used to generate the horizontal and vertical drive timing required when the aerial camera does not perform image shift compensation. The vertical charge transfer bus interface module is used to receive the vertical image shift compensation time interval information from the camera controller; the vertical image shift compensation timing control module is used to generate timing pulses based on the time interval information during exposure, and to generate the trigger signal and timing switching signal required for vertical image shift compensation based on the vertical operating state; the vertical image shift timing generation module generates the vertical image shift compensation drive timing based on the timing pulses, inputs the timing to the vertical drive circuit, amplifies the vertical drive signal, and drives the charge to transfer in the vertical direction, compensating for the component of image shift in the vertical transfer direction on the image plane. The horizontal charge transfer bus interface module is used to receive horizontal image shift compensation time interval information from the camera controller; the horizontal image shift compensation timing control module is used to generate timing pulses according to the time interval information during exposure, and to generate trigger signals and timing switching signals required for horizontal image shift compensation according to the horizontal working state; the horizontal image shift timing generation module generates horizontal image shift compensation drive timing according to the timing pulses, inputs the timing to the horizontal drive circuit, the horizontal drive circuit amplifies the horizontal drive signal, drives the charge to transfer in the horizontal direction, and compensates for the component of image shift in the horizontal transfer direction of the image plane.

[0032] The aforementioned two-dimensional directional charge transfer array CCD detector is used to compensate for multi-degree-of-freedom image shift in aerial cameras. For example... Figure 3 As shown, the two-dimensional directional charge transfer array CCD detector has pixels arranged in rows and columns. All pixels transmit pixel information at the same or different rates in the row and column directions. The driving circuit can control the charge to drive the charge to transfer charge along the row and column directions respectively.

[0033] It should be noted that during exposure, charges containing scene information are collected onto the pixels of the array. First, according to the speed of each column, the charges are moved from one pixel to another in the column direction. After the column direction movement is completed, the charges are moved from one pixel to another in the row direction according to the speed of each row. After the exposure is completed, the charges containing scene information are sequentially read from the array into a register. The read image signal is sent from the register to the front-end signal processing circuit. After the image signal is read out, the array can proceed to the next exposure. Because the image shift caused by aircraft motion can be decomposed in the horizontal and vertical directions of the image plane, if the charges are synchronized with the horizontal and vertical image shift in the row and column directions under the drive clock, the horizontal and vertical image shift components can be compensated. Therefore, the image shift caused by the multi-degree-of-freedom motion of the aircraft, such as roll, pitch, and yaw, can be eliminated.

[0034] The front-end signal processing circuit performs correlation double sampling, controllable gain amplification, dark level clamping compensation, and analog-to-digital conversion on the analog signal output by the two-dimensional directional charge transfer array CCD detector. The interface circuit is a Cameralink interface, which is responsible for outputting the digital image signal generated by the analog-to-digital converter from the camera and providing an interface for communication with the host computer.

[0035] The camera controller can be developed using the STM32F103ZET6 microcontroller, the multi-degree-of-freedom image shift compensation timing generator can be developed using the ZYNQ7000 FPGA development board, the horizontal drive circuit can be developed using the 74ACT04 dedicated chip, the vertical drive circuit can be developed using the TDA9991 dedicated chip, the front-end signal processing circuit can be developed using the TDA9965, and the interface circuit can be developed using the DS90CR287 dedicated chip.

[0036] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0037] The above embodiments merely illustrate preferred implementations of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A driving circuit supporting multi-degree-of-freedom image shift compensation function, characterized in that, include: The system comprises a camera controller, a multi-degree-of-freedom image shift compensation timing generator, a vertical drive circuit, a two-dimensional directional charge transfer (TCT) array CCD detector, a horizontal drive circuit, a front-end signal processing circuit, and an interface circuit. The camera controller is connected to the multi-degree-of-freedom image shift compensation timing generator. The multi-degree-of-freedom image shift compensation timing generator is connected to the vertical drive circuit, the TCT array CCD detector, and the horizontal drive circuit. The vertical drive circuit and the horizontal drive circuit are also connected to the TCT array CCD detector. The TCT array CCD detector is connected to the front-end signal processing circuit, and the front-end signal processing circuit is connected to the interface circuit. The two-dimensional directional charge transfer array CCD detector is used to compensate for multi-degree-of-freedom image shift of aerial cameras. The two-dimensional directional charge transfer array CCD detector has pixels arranged in rows and columns. All pixels transmit pixel information at the same or different rates in the row and column directions. The driving circuit can control the charge to drive the charge to transfer along the row and column directions respectively. The multi-degree-of-freedom image shift compensation timing generator includes: a main timing generator, a vertical charge transfer bus interface module, a vertical direction image shift compensation timing control module, a vertical direction image shift timing generation module, a horizontal charge transfer bus interface module, a horizontal direction image shift compensation timing control module, and a horizontal direction image shift timing generation module. The main timing generation module is used to generate the horizontal and vertical drive timing required when the aerial camera does not perform image shift compensation. The vertical charge transfer bus interface module is used to receive the vertical image shift compensation time interval information from the camera controller. The vertical image shift compensation timing control module is used to generate timing pulses based on the time interval information during exposure, and to generate the trigger signal and timing switching signal required for vertical image shift compensation based on the vertical operating state. The vertical image shift timing generation module generates the vertical image shift compensation drive timing based on the timing pulses. The horizontal charge transfer bus interface module is used to receive the horizontal image shift compensation time interval information from the camera controller. The horizontal image shift compensation timing control module is used to generate timing pulses based on the time interval information during exposure, and to generate the trigger signal and timing switching signal required for horizontal image shift compensation based on the horizontal operating state. The horizontal image shift timing generation module generates the horizontal image shift compensation drive timing based on the timing pulses.

2. The driving circuit supporting multi-degree-of-freedom image shift compensation function according to claim 1, characterized in that, The camera controller is connected to the vertical charge transfer bus interface module, the horizontal charge transfer bus interface module, and the main timing generation module. The horizontal charge transfer bus interface module is connected to the horizontal image shift compensation timing control module, which is connected to the horizontal image shift timing generation module. The vertical charge transfer bus interface module is connected to the vertical image shift compensation timing control module, which is connected to the vertical image shift timing generation module. The vertical image shift timing generation module is connected to the vertical drive circuit, and the horizontal image shift timing generation module is connected to the horizontal drive circuit.

3. The driving circuit supporting multi-degree-of-freedom image shift compensation function according to claim 1, characterized in that, The camera controller uses the received aircraft and detector information to generate task parameters for multi-degree-of-freedom image shift compensation for the aerial camera, and sends the task parameters to the multi-degree-of-freedom image shift compensation timing generator.

4. The driving circuit supporting multi-degree-of-freedom image shift compensation function according to claim 1, characterized in that, The front-end signal processing circuit performs correlation double sampling, controllable gain amplification, dark level clamping compensation, and analog-to-digital conversion on the analog signal output by the two-dimensional directional charge transfer array CCD detector. The interface circuit is responsible for outputting the digital image signal generated by the analog-to-digital converter from the camera and providing an interface for communication with the host computer.

5. The driving circuit supporting multi-degree-of-freedom image shift compensation function according to claim 1, characterized in that, The camera controller is developed using a microcontroller, the multi-degree-of-freedom image shift compensation timing generator is developed using an FPGA, the two-dimensional directional charge transfer array CCD detector is a customized detector, the vertical drive circuit and the horizontal drive circuit are developed using dedicated chips, the front-end signal processing circuit is developed using dedicated chips, and the interface circuit is developed using dedicated chips.

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