Radiation-resistant camera based on holder rotation

Abstract

The invention discloses a radiation-resistant camera based on rotation of a holder. A radiation-resistant monitoring device mainly comprises 13 radiation-resistant high-definition cameras (12 cameras and 1 camera), a video compensation exchange control box and 13 camera special control cables (the same number of cameras). And after video signals of each channel are processed by the video compensation exchange control box and are converted into network signals, data collection is carried out inside and the network signals are distributed outwards. The distributed data can be accessed to a rear-end main console computer, a multifunctional controller, a video server and other general network equipment to form a monitoring network, so that the problem that the space of a display platform is inconvenient to fully utilize is solved, and a radiation-resistant camera can complete high-definition real-time video acquisition in a nuclear radiation area. The camera is provided with a two-dimensional holder, so that two-dimensional rotation, illumination brightness adjustment and camera zooming operation can be carried out; control can be carried out through a software interface of a back-end network device (such as an NVR), and operation control can also be carried out through self-design of a PC software client. And the video compensation exchange control box collects data of all cameras, can output network video stream signals conforming to an ONVIF protocol, and can access back-end general network equipment for storage, display and video playback, so that the flexibility of the radiation-resistant camera is improved.

Description

Technical Field

[0001] The invention relates to the technical field of radiation-resistant cameras, in particular to a radiation-resistant camera based on pan-tilt rotation. Background Art

[0002] In high-radiation environments such as nuclear energy, medical radiotherapy, and aerospace, traditional cameras often cannot work stably for a long time due to the limited radiation resistance of materials and electronic components. Therefore, designing a camera that can maintain high performance in a high-radiation environment is of great significance for monitoring, recording, and analyzing key data in these environments. The radiation-resistant camera system is mainly used for remote real-time video monitoring in radiation environments. Operators can remotely operate multiple radiation-resistant cameras arranged in the radiation area from the monitoring station. The camera has real-time high-definition video acquisition, pan-tilt two-dimensional rotation and speed control, camera zoom control, lighting switch and brightness adjustment, etc. The real-time images of all cameras can be displayed on the same screen on the monitoring station NVR or other network terminal devices.

[0003] The radiation-resistant camera system is mainly used for remote real-time video monitoring in radiation environments. Operators can remotely operate multiple radiation-resistant cameras arranged in the radiation area from the monitoring station. The camera has real-time high-definition video acquisition, PTZ two-dimensional rotation and speed control, camera zoom control, lighting switch and brightness adjustment, etc. The real-time images of all cameras can be displayed on the same screen on the monitoring station NVR or other network terminal devices. Summary of the invention

[0004] The purpose of the present invention is to provide a radiation-resistant camera with a pan-tilt rotation to solve the problem that the camera is inconvenient to operate stably for a long time in a high-radiation environment.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a radiation-resistant camera with pan-tilt rotation, which adopts a U-shaped frame two-dimensional turntable structure, and a precision DC reduction motor drives a worm gear as a transmission mechanism to drive the camera shielding body to rotate, and has the advantages of simple structure, small volume, high load, and convenient maintenance; Also includes: The height structure of the pan / tilt adopts worm gear transmission, and the DC motor drives the worm to rotate, realizing the rotation of the worm gear, so that the radiation-resistant camera can move up and down with the transmission mechanism to achieve the observation of targets in high and low directions. In order to achieve a wide range of observation effects, the height rotation angle is designed to be ±110°; The LED lighting is no less than four; The radiation-resistant camera comes with a gimbal fixed mounting flange. Screw holes and through holes are left on the gimbal flange to facilitate the connection of the gimbal to the on-site fixed mounting base through 6 M8 bolts; Lighting system: The lighting system is used to meet the needs of insufficient lighting on site. An LED lighting system is designed and arranged on the camera shielding shell to facilitate the consistency of the field of view direction and the lighting direction. At the same time, the illumination angle of the lighting lamp can be set to 30° or 60° through different lens selections, which needs to be reasonably selected according to the observation range of the on-site camera. Considering the requirements of electromagnetic compatibility, the lighting system is designed and installed around both sides of the U-shaped frame. The lighting light source adopts a high-brightness LED bulb, which has low lighting power, high brightness and long life. Considering the weight of the equipment and the requirements of lightness of use, except for the camera protective shell which is made of tungsten-nickel-copper alloy, other materials of the equipment are made of 6061 aluminum alloy. The surface of the main aluminum alloy material is anodized to enhance the surface wear resistance, hardness and corrosion resistance; By adopting the above technical solution, the height / horizontal mechanism of the two-dimensional gimbal of the radiation-resistant camera is the actuator of the worm gear transmission mechanism, and a DC motor with a planetary gear box is used as the power drive unit to realize the rotational movement of the gimbal.

[0006] Preferably, the gimbal camera part mainly includes a radiation-resistant camera, a group of 4 LED lighting lamps, a pitch drive motor, a horizontal electric drive motor, an LED light drive board, a gimbal pitch motion limit control board, a conductive ring and an aviation socket for connecting cables.

[0007] Radiation-resistant cameras are mainly used for real-time video acquisition in front-end radiation areas. Since the module will be affected by nuclear radiation and its performance will gradually decline, considering the convenience of subsequent repair and maintenance, the camera is designed as an independent and quickly replaceable module. The camera can be quickly replaced by simply removing the wiring strip above.

[0008] By adopting the above technical solution, the LED lighting group provides sufficient and uniform lighting for the camera. Here we have carried out radiation screening on the industrial-grade LED lamp beads on the market and selected lamp beads with better radiation resistance. The designed rated power is 10W. In actual use, in order to extend the service life of the lamp, a derating design is carried out and the power is limited to 4W.

[0009] LED lighting uses a near-end constant current drive method to improve the working stability of the LED light module and reduce the heat generated by the power module. The maximum design power of the LED module can reach 60W, but the actual use is only 16W, which is a derating of more than 60%.

[0010] Due to the limitation of mechanical structure, the two-dimensional rotation angle of the two-dimensional pan / tilt needs to be set within a range. The pan / tilt limit plate is mainly used to lock the extreme position of the pan / tilt two-dimensional rotation. When the pan / tilt rotates to the extreme position in one direction, the protection circuit on the limit plate will cut off the motor drive signal, thereby locking the motor before the pan / tilt moves to the mechanical limit, thus protecting the mechanical structure. The drive signal is cut off by a contact switch, and the effective use number of contacts exceeds 100,000 times, which can ensure the reliable use of the limit switch throughout the life of the radiation-resistant camera.

[0011] The horizontal rotation of the gimbal can achieve 360° full-directional rotation because of the addition of a conductive ring. Here we use a customized high-performance conductive slip ring, which can not only transmit power and control signals, but also achieve lossless transmission of image signals. It also has strong resistance to vibration and impact.

[0012] Preferably, the radiation-resistant camera can perform electronically controlled magnification and zoom operations to control the distance of the camera's field of view, that is, to enlarge or reduce the field of view.

[0013] By adopting the above technical solution, a radiation-resistant zoom lens is independently designed here. It consists of three radiation-resistant lenses, including a main mirror, a zoom adjustment mirror, and a magnification adjustment mirror. The light is focused on the image sensor after passing through an IR filter at the rear end.

[0014] Preferably, the zoom lens adopts an embedded lens structure, that is, the main mirror is fixed.

[0015] By adopting the above technical solution, the position of the zoom lens and the zoom lens can be adjusted to achieve the adjustment of the zoom and zoom of the lens. Ordinary lens lenses have not been specially processed, and will seriously degrade after accumulating a certain dose of radiation (generally within 1000Gy). Specifically, the overall color of the lens will become darker, the transmittance of visible light will be greatly reduced, and finally it will even completely lose its transmittance. Here we use lenses made of special materials, which add special materials such as oxidation to the lenses, so that the lenses can withstand a certain amount of radiation accumulation without obvious material changes, ensuring the transmittance of the lenses to visible light and achieving the function of radiation resistance.

[0016] The lens is driven by a micro-stepping motor and is driven by a pull rod to move back and forth on the slide bar. A Hall sensor is also set at the end to feedback the actual travel position of zoom and magnification. The drive signal of the zoom and focus motor, the Hall sensor signal, and the opening signal of the IR filter are all led out through the FPC cable, which makes the lens structure compact.

[0017] Preferably, the camera main control board mainly includes two key components required for imaging, an image sensor and a signal processor.

[0018] By adopting the above technical solutions, the current classic structure of cameras based on CIS image sensors is an image sensor plus an image signal processor. The image sensor is mainly used to collect image signals, that is, to perform photoelectric conversion on visible light signals, convert them into electrical signals of a certain format and send them out.

[0019] The main function of the signal processor is to perform some basic image processing on the original video signal output by the sensor, such as image white balance, image automatic gain, image bad pixel correction, image wide dynamic range correction, etc., so as to significantly improve the image quality relative to the original image. Preferably, a limit spring is connected to one side of the limit block, one end of the limit spring is fixedly connected to the limit block, and the other end of the limit spring is fixedly connected to the fixing plate.

[0020] By adopting the above technical solution, the shielding body is mainly used to shield and isolate radiation sensitive components, thereby achieving the purpose of reducing the radiation dose rate inside the shielding body.

[0021] Here we use tungsten alloy and lead glass as the main shielding materials, and the design index is 1 / 10, that is, the radiation dose rate inside the shielding body is reduced to about 1 / 10 of the outside.

[0022] According to the data obtained from the previous Monte Carlo test simulation, we selected the radiation-resistant lead glass of model ZF6, with a lead equivalent of 4.2, that is, every 10cm thick lead glass is equivalent to 4.2mm thick lead. At the same time, tungsten alloy with a density of about 18g / cm3 was used. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the 3D structure of the PTZ Figure 2 PTZ dimensions Figure 3 Schematic diagram of the mechanical structure of the pan / tilt Figure 4 2D PTZ Model Figure 5 Schematic diagram of radiation resistant probe structure Figure 6 Shield structure diagram Figure 7 Video compensation switching control box panel layout Figure 8 Radiation Tolerant Monitoring Equipment Connection Diagram DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Embodiment 1: Figure 1-2 As shown in the figure, the radiation-resistant camera adopts a U-shaped two-dimensional turntable structure. The precision DC reduction motor drives the worm gear as the transmission mechanism to drive the camera shield to rotate. It has the advantages of simple structure, small volume, high load, and easy maintenance. The horizontal rotation of the two-dimensional turntable is 360° without limit, and the limit switch is set in the high and low directions as the limit protection of the extreme position to achieve large field of view monitoring in different observation areas. The pan-tilt head is connected to the on-site fixed bracket through the bottom flange, and its bus socket is arranged at the bottom. The pan-tilt head can be installed in three ways: inverted hanging, side hanging and vertical installation.

[0026] Embodiment 2: Figure 3 As shown, the design of the pan / tilt structure should consider the overall structure from the perspectives of the system's height / horizontal transmission, lighting, electromagnetic compatibility, radiation protection, etc. At the same time, in order to control the weight and space size of the equipment, the pan / tilt structure fully considers simplicity. The height structure of the pan / tilt adopts worm gear transmission, and the worm is driven by a precision DC reduction motor to rotate the worm to achieve the rotation of the worm wheel, so that the radiation-resistant camera can move up and down with the transmission mechanism to achieve the purpose of accurately monitoring targets in the high and low directions. In order to achieve a wide range of observation effects, the height rotation angle is designed to be ±120°.

[0027] Embodiment 3: Figure 4-5 As shown, the probe is driven to rotate up and down through a worm gear reduction mechanism, and touch switches and mechanical stops for limiting are set at the ±120° positions of the rotating shaft. This double limit protection mechanism can effectively ensure the upper limit of the high and low rotation angles, and avoid the failure of a single limit that causes the angle of the entire motion mechanism to be unrestricted.

[0028] The horizontal rotating shaft is also driven by a worm gear reduction mechanism. The difference from the high and low rotating mechanism is that the horizontal rotating shaft is fixed during movement, that is, the worm gear is fixedly connected to the mounting flange, and the worm gear rotates around the worm gear, thereby driving the entire U-shaped frame to rotate horizontally.

[0029] The power, signal, and control cables of the entire radiation-resistant camera are connected to the PTZ through the aviation socket at the top, and the cables are transferred through the conductive ring installed inside the horizontal shaft of the PTZ. The conductive ring enables the PTZ to have the ability to rotate 360° horizontally without restrictions, while also ensuring that the cables inside the shaft will not be knotted or twisted due to rotation, avoiding damage to the equipment by pulling the cables during use. The 360° unlimited horizontal angle also provides a larger field of view for on-site monitoring work, ensuring that there are no blind spots in monitoring.

[0030] The lighting system is used to meet the needs of insufficient lighting on site. The lighting system is designed and arranged on the shielding shell of the PTZ main camera to facilitate the consistency of the field of view and the lighting direction. At the same time, the illumination angle of the lighting lamp can be selected as 30° or 60°, which can be reasonably selected according to the needs of the site.

[0031] Considering the requirements of electromagnetic compatibility, the lighting system is designed and installed around both sides of the U-shaped frame. The lighting source uses high-power LED lamp beads, which have low lighting power, high brightness and long life. Since LED lamps need to have good heat dissipation function when in use to reduce their life thermal attenuation, the four LED lamps are tightly installed on an aluminum alloy heat dissipation substrate, and the substrate is fixed to the camera housing, so that the heat generated by the LED during operation can be quickly and efficiently exported to the camera housing, effectively avoiding the problem of life attenuation and reduced illumination caused by heat accumulation of LED lamps.

[0032] Considering the weight and portability of the equipment, the equipment uses 6061 / 7075 high-strength aluminum alloy materials except for the camera protective shell, which is made of tungsten-nickel alloy. The main aluminum alloy material is aging treated and the surface is anodized to enhance the surface wear resistance, hardness and corrosion resistance.

[0033] Embodiment 4: Figure 6-7 The shield shown is mainly used to shield and isolate radiation-sensitive components, and to reduce the radiation dose rate inside the shield. Here we use tungsten alloy and lead glass as the main shielding materials, and the design index is 1 / 10, that is, the radiation dose rate inside the shield is reduced to about 1 / 10 of the outside.

[0034] We use radiation-resistant lead glass of model ZF6, with a lead equivalent of 4.2, that is, every 10cm thick lead glass is equivalent to 4.2mm thick lead. At the same time, tungsten alloy with a density of about 18g / cm3 is used. The video compensation switching control box is fixed to the cabinet through the mounting holes on both sides of the front panel. The main power switch of the chassis is arranged on the front panel; the cooling fans of the equipment are on both sides of the chassis. Through the design of one side for air intake and one side for air outlet, a good air duct is formed inside the equipment, and the internal heat is quickly discharged to ensure that the equipment can run well and stably. There are a total of 18 quick sockets on the rear panel of the chassis, one of which is the 220V power input port of the equipment, 4 are dedicated network ports, 12 common channels, and 1 spare channel.

[0035] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0036] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A radiation-resistant camera based on pan-tilt rotation, a radiation-proof camera, comprising a camera body 1, the camera body 1 is fixed in a shell 2 through a mounting seat 10, the shell 2 is a tubular structure with a hollow interior and an open end, a cover 3 is installed at the open end of the shell 2, the lens of the camera body 1 corresponds to the cover 3, the cover 3 is sealed and installed at the open end of the shell 2, a cable connector 4 is provided at the non-open end of the shell 2, the cable connector is waterproof, the cable connector 4 is used to install a waterproof cable, one end of the cable is electrically connected to the camera body 1 through the cable connector, and the other end is electrically connected to an external device, and the external device includes a power supply; the material of the shell 2 is tungsten-nickel alloy.

2. Specifically, the material of the cover 3 is leaded glass, grade ZF7. Leaded glass has great impact resistance and radiation resistance. Therefore, the cover 3 is set to leaded glass, which can effectively resist radiation. In this embodiment, the cover 3 is cylindrical, and its outer surface is provided with external threads, and the inner surface of the open end of the shell is provided with internal threads. The cover is embedded in the open end of the shell, and the external threads and the internal threads cooperate to achieve thread fixation.

3. A threaded pressing ring 8 is provided on the outer end face of the cover body 3, and the cover body 3 is pressed against the open end of the shell body 2 by means of the threaded pressing ring 8. An external thread is formed on the outer surface of the threaded pressing ring 8, and an internal thread matching the external thread is formed on the inner end face of the open end of the shell body. When the threaded pressing ring 8 is screwed on the cover body 3, the cover body 3 is first embedded in the shell body 2, and then the threaded pressing ring 8 is screwed on to press it against the outer end face of the cover body 3. The provision of the threaded pressing ring 8 ensures that the cover body 3 is firmly installed.

4. The cable connector 4 is tubular, one end of which is threadedly connected to the mounting hole, and the other end protrudes from the non-open end of the housing 2; a second sealing ring 6 is embedded between one end of the cable connector 4 and the mounting hole.

5. Specifically, the inner end surface of the cover body 3 extends into the shell body 2, and an annular light source 7 is arranged at the inner end surface. The light source 7 is a point light source, and the granular point light sources are distributed circumferentially along the inner end surface of the cover body 3 to form a ring; the annular light source 7 is electrically connected to the corresponding cable, and the light source 7 provides illumination for the camera body in the shell, further improving the image acquisition effect of the camera.

6. Its specific working principle is as follows: the radiation-proof camera is used in deep water in a strong radiation environment. The lens shoots the target image through a transparent cover. The shell is set to a columnar shape, which can reduce the diving resistance of the shell and facilitate the camera to dive 50m to 100m underwater. In addition, the setting of the tungsten-nickel alloy shell, lead-containing glass cover, and flexible graphite sealing ring in the camera makes the camera's radiation resistance up to 1000Gy cumulative dose, effectively improving the radiation protection ability of the camera body; the cover is fixed to the shell by thread and tightened by a threaded ring, further improving the sealing inside the shell and the waterproof ability of the camera and large pressure shock, so that the camera can operate in deep water; and the high radiation resistance and high waterproofness effectively avoid the performance of the camera being affected, while increasing the service life.

7. The above is only the preferred implementation mode of the present application, and the present invention is not limited to the above embodiments. It can be understood that other improvements and changes directly derived or associated by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included in the scope of protection of the present invention.

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