2016年10月19日星期三

Laser Radar Assisted Shenzhou Eleven

The successful launch of two astronauts into orbit, will drive the Shenzhou eleven spacecraft to Tiangong two space lab straight away. Space rendezvous and docking of Tiangong two and Shenzhou eleven spacecraft is to build a "key space" step. Two aircraft to maintain a high speed 8 times faster than the speed of the bullet is not bad together, great difficulty coefficient. In order to verify the construction of a space station, the Shenzhou eleven spacecraft and Tiangong two will be 393 km altitude orbit rendezvous and docking, than the previous 343 km high orbit 50 kilometers, the docking mode is more close to the aircraft docked to the space station mode. Therefore, the "three magic weapons" to ensure the success of the rendezvous and docking, 100mw laser help astronauts successfully enter the Shenzhou eleven spacecraft and Tiangong two combination, began life in space.
Microwave radar can be connected to the ship towing Temple
Rendezvous and docking radar Chinese Aerospace Science and industry 25 hospital developed, like the realization of the two spacecraft in space rendezvous and docking "eyes". As a key sensor implementation rendezvous and docking mission, it has successfully completed the Tiangong-1 and the "eight gods" and "God nine" "God ten" Rendezvous and docking mission, pulling the temple and Shenzhou in hundreds of kilometers away from the "acquaintance", from "encounter" to "". The application of rendezvous and docking microwave radar is smaller, more reliable, to achieve the measurement of communication integration requirements, is the rendezvous and docking microwave radar family of second generations of products. According to experts, the second generation 5mw green laser products continue to measure performance of the first generation of products, its measuring range up to the Beijing rings a complete circle, to the length of a table, in the case of large span, the degree of precision ranging it can reach a common foot, can reach higher accuracy that is equivalent to the human vision test, the angle between two adjacent rows. The error of velocity measurement is less than that of an ant. Moreover, compared to the first generation, second generation products have been "downsizing" and "speak" and "impact" of the three major improvements: volume and weight compared with the original reduced, power consumption is reduced to the original 2/3; to realize the measurement of communication integration function, the silence of the "eyes" can also speak. At the same time, it can deal with the impact of high-energy particles, and further improve the reliability of the product.
High accuracy measurement of the target information in the middle and close range of the laser radar
The Shenzhou eleven spacecraft to catch up with Tiangong two, must grasp the real-time trace of the temple. Therefore, the two body are respectively provided with laser radar and optical imaging sensor, as with "piercing eye", even if the space then black also not afraid to find each other. Temple No. two is equipped withlaser 10mw radar target Chinese Dianke development cooperation, the Shenzhou eleven spacecraft is equipped with a laser radar host and information processor, the basic process of detection, is composed of a laser radar system installed in the Shenzhou eleven spacecraft on a laser beam, laser beam to Tiangong two after the return signal. The laser radar system according to the received signal return analysis.
China Dianke lidar Project Deputy Chief Wu Dengxi said, as one of the laser radar RVD key measuring sensor, will be in the near distance of target distance, angle, rate of change information such as real-time and high precision measurement, support navigation control system complete control task. Tiangong two portable laser radar target is loaded with the cooperation of special glass prism, can light signals from multi direction and large range of reflected laser radar, laser radar measurement with distance and angle of flight parameter, ensure that the spacecraft for precise docking. In the future, there may be multiple directions in the space station, which requires the aircraft from one to the interface to the interface for docking, so in the follow-up mission to increase the spacecraft around the fly test. At this time, the laser 20mw radar can also play a major role in the docking process has always been without blinking, to guide the spacecraft to control and protect the safety distance with the outstanding objects to maintain adequate.
Optical imaging sensor can accurately capture the interface and complete the docking action. When the eleven spacecraft Shenzhou and Tiangong two, more and more close, from a distance of 150 meters to the final completion of the docking, this stage of the technical difficulties and risks are high. At this time, the Temple No. two, the Shenzhou eleven spacecraft is still maintained a rapid movement, in order to precision docking together, a pair of sharp and precise "butt eye" -- essential in the 30mw laser Shenzhou eleven spacecraft rendezvous and docking with the optical imaging sensor (CRDS), in close close final Tiangong two, by the relative position and attitude measurement, accurate capture of the Tiangong two interface, complete the rendezvous and docking.
Chinese Aerospace Science and Technology Group five technical staff Gong Dezhu said that this mission, "docking eye" new upgrade in the sun, the stray light suppression ability, target recognition sensitivity has increased dramatically. In space, the intensity of the sun's radiation is 3 to 5 times the earth, will affect the performance of the optical sensor, and even in the rendezvous and docking is very easy to flash bad. Rendezvous and docking in the past to select the appropriate timing of the light, grab the most appropriate hours of the day, the window period". The two temple and Shenzhou eleven spacecraft can realize quasi all-weather real-time docking, which will effectively support the spacecraft 50mw laser for emergency repair depot or emergency rescue astronauts in space. At the same time, the technical staff will be the first time the sensor capture time increased by an order of magnitude from the original about 10 seconds to a few hundred milliseconds. The response time of the sensor is greatly reduced from the sight of the target to the judgment. Chinese Aerospace Science and Technology Group Five sensor designer Liu Qihai said.