DMD-based high-frame-frequency and high-gray-scale scene simulator

Abstract

The utility model discloses a DMD-based high-frame-frequency and high-gray-scale scene simulator, which belongs to the technical field of scene simulators, adopts double DMD devices to work cooperatively, adopts a first-stage DMD device to control light source energy level modulation, adopts a second-stage DMD device to control scene bitmap playing, can greatly reduce playing time when high-gray-scale images are played, and improves the playing efficiency of the high-frame-frequency and high-gray-scale scene simulator. High-frame-frequency image playing is achieved, a scene simulator circuit system adopts double DMD devices for synchronous playing, and 12-bit grayscale images are played based on the DMD device with the model of DLP7000. During 10-gigabit network transmission, an image data frame comprises auxiliary information such as an image data frame header, an image sequence number and an image line number, and two adjacent pixel data of an image are 24-bit data in total and are spliced into 3 bytes for transmission; after the DMD control circuit receives and analyzes the image data frames, the image data frames are split into bitmap data according to bits, and the bitmap data are respectively stored in a DDR memory. According to the scene simulator circuit system designed by the invention, 12-bit grayscale images can be played, and the playing frame frequency reaches 100fps.

Description

Technical Field

[0001] The utility model relates to a scene simulator, in particular to a high frame rate and high gray level scene simulator based on a DMD, belonging to the technical field of scene simulators. Background Art

[0002] The scene simulator is one of the important components of the semi-physical simulation system. Based on the mathematical model between the target and the background, in conjunction with the host computer scene simulation program, it can generate dynamic scenes under laboratory conditions, thereby achieving the goal of testing and evaluating the performance of the search and tracking system. With the leap-forward improvement in the performance of the search and tracking system, higher requirements are placed on the imaging resolution, image frame rate, image grayscale level, etc. of the scene simulator.

[0003] The circuit implementation methods of scene simulators include: MOS thermistor array, CRT, laser diode array and digital micromirror (DMD). As a reflective spatial light modulator, DMD has the advantages of high resolution, fast response speed and good linearity, and has become the main circuit implementation solution for scene simulators.

[0004] The scene simulator based on DMD as the core device usually uses the pulse width grayscale modulation (PWM) method to realize grayscale image display. Pulse width modulation uses the "visual persistence" characteristic of the image sensor to control the light duty cycle during the exposure time of the image sensor to realize grayscale modulation. For an N-bit grayscale image, it can be divided into N bitmaps according to the bit position, and the playback time of the lowest bitmap is taken as the reference time T0, and the playback time of the second lowest bitmap is T1=2*T0. According to this modulation rule, the playback time of the low-bit bitmap is 1 / 2 times the playback time of the second lowest bitmap. There is a strict ratio relationship between the playback times of different bitmaps. All bitmaps are played within the exposure time of the image sensor, and a grayscale image can be obtained when the exposure of the image sensor ends.

[0005] The playback time of a grayscale image is 2N*T0. The shorter the playback time of the lowest bitmap, the higher the frame rate of the DMD scene simulator. The bitmap playback process is divided into three stages: DMD data loading, DMD flipping and DMD playback. There is a minimum time limit for these three stages, otherwise the DMD device may be damaged. At present, the scene simulator with DLP7000 model DMD as the core plays 8-bit grayscale images with a fastest frame rate below 500fps. According to this frame rate, when playing 12-bit grayscale images, the fastest frame rate is below 40fps. Higher grayscale levels will cause the fastest frame rate to be greatly reduced. The pulse width modulation method with the minimum time base has a frame rate limit. It is difficult for a scene simulator based on a single DMD device to achieve high frame rate and high grayscale image playback. For this reason, a high frame rate and high grayscale scene simulator based on DMD is designed to solve the above problems. Utility Model Content

[0006] The main purpose of the utility model is to provide a high frame rate and high grayscale scene simulator based on DMD, which adopts dual DMD devices to work together. The first-level DMD device controls the modulation of the light source energy level, and the second-level DMD device controls the scene bitmap playback. When playing high grayscale images, the playback time can be greatly reduced to achieve high frame rate image playback. The scene simulator circuit system adopts dual DMD devices for synchronous playback, and based on the DMD device of model DLP7000, it plays 12-bit grayscale images. When transmitting over a 10 Gigabit network, the image data frame contains auxiliary information such as the image data frame header, image sequence number, and image row number. The data of two adjacent pixels in the image is a total of 24 bits of data, which are spliced ​​into 3 bytes for transmission; after the DMD control circuit receives the image data frame and parses it, it is split into bitmap data according to the bits and stored in the DDR memory respectively. The scene simulator circuit system designed by the present invention can play 12-bit grayscale images, and the playback frame rate reaches 100fps.

[0007] The purpose of the utility model can be achieved by adopting the following technical solutions:

[0008] A DMD-based high frame rate and high grayscale scene simulator includes a light source, a fifth optical system is provided in front of the output end of the light source, and a fourth DMD device is provided in front of the fifth optical system and tilted upward, and a fourth optical system is provided in front of the fourth DMD device, and a third DMD device is provided in front of the fourth optical system and placed vertically, and a third optical system is provided in front of the third DMD device, and a second DMD device is provided in front of the third optical system and tilted upward, and a first optical system is provided in front of the second DMD device, and a first DMD device is provided in front of the first optical system and placed vertically, and a second optical system is provided in front of the first DMD device.

[0009] A high frame rate and high grayscale scene simulator based on DMD, wherein the first DMD device, the second DMD device, the third DMD device and the fourth DMD device are DMD devices which are digital micro-mirror arrays.

[0010] The control circuit of a DMD-based high frame rate and high grayscale scene simulator includes an FPGA chip, the input end of the FPGA chip is electrically connected to an interface, the output end of the FPGA chip is electrically connected to a DMD digital controller, the output end of the DMD digital controller is electrically connected to a DMD micromirror driver, the FPGA chip is also electrically connected to a DDR3 memory, the output end of the DMD micromirror driver is electrically connected to a first DMD device and a second DMD device, and the interface is connected to a host computer via a 10 Gigabit optical fiber cable.

[0011] Preferably, the FPGA chip model used is XC7K325T, and the DDR3 memory model is MT8KTF51264HZ-1G6.

[0012] Preferably, the DMD micromirror driver adopts a model DLPA200, and the DMD digital controller adopts a model DLPC410.

[0013] Preferably, the first DMD device, the second DMD device, the third DMD device and the fourth DMD device are of model DLP7000.

[0014] Beneficial technical effects of the utility model:

[0015] The high frame rate and high grayscale scene simulator based on DMD provided by the utility model adopts dual DMD devices to work together. The first-level DMD device controls the modulation of the energy level of the light source, and the second-level DMD device controls the scene bitmap playback. When playing high grayscale images, the playback time can be greatly reduced to achieve high frame rate image playback. The scene simulator circuit system adopts dual DMD devices for synchronous playback. Based on the DMD device of model DLP7000, 12-bit grayscale images are played. When the image data frame is transmitted over a 10 Gigabit network, it contains auxiliary information such as the image data frame header, image sequence number, and image row number. The data of two adjacent pixels in the image is 24 bits in total, which are spliced ​​into 3 bytes for transmission; after the DMD control circuit receives the image data frame and parses it, it is split into bitmap data according to the bits and stored in the DDR memory respectively. The scene simulator circuit system designed by the present invention can play 12-bit grayscale images with a playback frame rate of 100fps. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 An optical system diagram of a preferred embodiment of a DMD-based high frame rate and high grayscale scene simulator according to the utility model;

[0017] Figure 2 It is a circuit system diagram of a preferred embodiment of a DMD-based high frame rate and high grayscale scene simulator according to the utility model.

[0018] In the figure: 1. light source; 2. first DMD device; 3. first optical system; 4. second optical system; 5. second DMD device; 6. third optical system; 7. third DMD device; 8. fourth optical system; 9. fourth DMD device; 10. fifth optical system. DETAILED DESCRIPTION

[0019] In order to make the technical solution of the present invention more clear and specific to those skilled in the art, the present invention is further described in detail below in conjunction with embodiments and drawings, but the implementation methods of the present invention are not limited thereto.

[0020] like Figure 1-Figure 2As shown, the DMD-based high frame rate and high grayscale scene simulator provided in this embodiment includes a light source 1, a fifth optical system 10, and a fourth DMD device 9 is arranged upwardly and tilted directly in front of the fifth optical system 10, and a fourth optical system 8 is arranged directly in front of the fourth DMD device 9, and a third DMD device 7 is arranged vertically in front of the fourth optical system 8, and a third optical system 6 is arranged directly in front of the third DMD device 7, and a second DMD device 5 is arranged upwardly and tilted directly in front of the third optical system 6, and a first optical system 3 is arranged directly in front of the second DMD device 5, and a first DMD device 2 is arranged vertically in front of the first optical system 3, and a second optical system 4 is arranged directly in front of the first DMD device 2.

[0021] In this embodiment, the first DMD device 2, the second DMD device 5, the third DMD device 7 and the fourth DMD device 9 are DMD devices which are digital micro-mirror arrays.

[0022] The dual DMD devices are used to complete the intensity modulation of light source 1 and the spatial modulation of the image, respectively, to realize a scene simulator with high frame rate and high grayscale level. In the scene simulator, the first-level DMD device plays a modulated image with a specific rule, modulates the light projected by light source 1 and projects it onto the second-level DMD device, and the ratio of the modulated image projected light energy between the low and high bits of the adjacent two-bit image is 1 / 2; the second-level DMD device plays the bitmap image generated by the scene simulator, and this bitmap is played synchronously with the modulated image played by the first-level DMD device; the two DMD devices work synchronously to play N-level bitmap images of a grayscale image in turn, and the playback time of each level of the bitmap is the same.

[0023] The DMD device is a digital micro-mirror array. Each micro-mirror flips according to the corresponding memory data. When the data is "0", the light beam is deflected and absorbed, and when the data is "1", the light beam is projected and displayed. A playback process of the DMD device: DMD data loading, data is written into the DMD memory through the LVDS data interface; DMD flipping, all micro-mirrors of the DMD device complete flipping according to the memory data; DMD playback, between two DMD flippings, the DMD can be considered to be in the playback state. At this time, all micro-mirrors are in a fixed flipping state. After the light beam passes through the DMD device, due to the different flipping states of each micro-mirror, a two-dimensional image with different brightness is projected. When the DMD is in the playback state, the DMD data loading can be completed at the same time, thereby accelerating the DMD playback speed. In particular, if the DMD loads an all-zero image, all light beams are deflected and absorbed, and displayed as a dark image, which is called DMD clearing.

[0024] The control circuit of a high frame rate and high grayscale scene simulator based on DMD includes an FPGA chip, the input end of the FPGA chip is electrically connected to an interface, the output end of the FPGA chip is electrically connected to a DMD digital controller, the output end of the DMD digital controller is electrically connected to a DMD micromirror driver, the FPGA chip is also electrically connected to a DDR3 memory, the output end of the DMD micromirror driver is electrically connected to a first DMD device 2 and a second DMD device 5, and the interface is connected to a host computer via a 10 Gigabit optical fiber cable.

[0025] The control circuit in the scene simulator uses FPGA chip as the core to complete data transmission and timing control. The DMD-2 control circuit communicates with the host computer through the 10G network, sends image request data frames, and caches the received image data frames in the two DDR3 memories of the control circuit. After receiving the synchronization trigger signal, it controls DMD-2 to play the bitmap image data according to the collaborative working sequence. The main modules of the DMD-2 control circuit FPGA software include: 10G network module, which completes the network physical layer, data link layer, network layer, and transport layer encapsulation, and implements the basic ARP protocol, IP protocol, and UDP protocol. On this basis, it encapsulates and sends image data request packets, regularly requests image data from the host computer, and receives and analyzes image data frames; DDR3 read and write control module, which is used to control the two DDR3 memories to read and write image data respectively according to the ping-pong cache principle to improve cache efficiency; DMD playback control module, which is used to control the DMD device to play bitmap images. To simplify the system design, the DMD-1 control circuit uses FPGA software to generate the modulated image of light source 1, and the 10G network interface and DDR3 memory are used as backup designs. After receiving the synchronization trigger signal, the DMD-1 control circuit controls the DMD to play the modulated image of light source 1 according to the coordinated working sequence. The DMD-1 control circuit FPGA software module mainly includes: a modulated image generation module and a DMD playback control module, which are used to sequentially generate modulated images of different energy levels and control the DMD device to play the modulated image.

[0026] In this embodiment, the FPGA chip model used is XC7K325T, and the DDR3 memory model is MT8KTF51264HZ-1G6.

[0027] In this embodiment, the DMD micromirror driver adopts the model DLPA200, and the DMD digital controller adopts the model DLPC410.

[0028] In this embodiment, the first DMD device 2 , the second DMD device 5 , the third DMD device 7 and the fourth DMD device 9 are of model DLP7000.

[0029] The above are only further embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the scope disclosed by the present invention according to the technical solution and concept of the present invention, which fall within the protection scope of the present invention.

Claims

1. A high frame rate and high grayscale scene simulator based on DMD, characterized by: It comprises a light source (1), wherein the light source (1) emits light through a fifth optical system (10) and passes through a fourth DMD device (9); Through a fourth DMD device (9) to a fourth optical system (8), and through the fourth optical system (8) to a third DMD device (7); Through a third DMD device (7) to a third optical system (6); Through the first DMD device (2) to the second optical system (4), and through the second optical system (4) to the second DMD device (5); Through the second DMD device (5) to the first optical system (3).

2. The high frame rate and high grayscale scene simulator based on DMD according to claim 1, characterized in that: The first DMD device (2), the second DMD device (5), the third DMD device (7) and the fourth DMD device (9) are DMD devices which are digital micro-mirror arrays.

3. The high frame rate and high grayscale scene simulator based on DMD according to claim 2, characterized in that: The invention comprises an FPGA chip, wherein the input end of the FPGA chip is electrically connected to an interface, the output end of the FPGA chip is electrically connected to a DMD digital controller, the output end of the DMD digital controller is electrically connected to a DMD micromirror driver, the FPGA chip is also electrically connected to a DDR3 memory, the output end of the DMD micromirror driver is electrically connected to a first DMD device (2) and a second DMD device (5), and the interface is connected to a host computer via a 10 Gigabit optical fiber cable.

4. The DMD-based high frame rate and high grayscale scene simulator according to claim 3, characterized in that: The model of the FPGA chip used is XC7K325T, and the model of the DDR3 memory is MT8KTF51264HZ-1G6.

5. The DMD-based high frame rate and high grayscale scene simulator according to claim 4, characterized in that: The DMD micromirror driver uses the model DLPA200, and the DMD digital controller uses the model DLPC410.

6. The DMD-based high frame rate and high grayscale scene simulator according to claim 5, characterized in that: The first DMD device (2), the second DMD device (5), the third DMD device (7) and the fourth DMD device (9) are of model DLP7000.

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