新一代精确制导武器用的卫星定位惯性导航组合

新一代精确制导武器用的卫星定位惯性导航组合 Satellite positioning / inertial navigation combination for a new generation of precision guided weapons Satellite positioning / inertial navigation (GPS/INS) integrated guidance technology is the most advanced, all-weather, autonomous Guidance technology has wide application prospects. It is the fourth generation of medium / long range precision guided air defense weapons developed abroad, Especially one of the key technologies adopted by the fourth generation precision guided bombs. The earliest airborne precision guided weapon (GPS/INS), which is the United States Navy's shipborne attack aircraft (A-7E) Equipment used by the "Ilam" (SLAM) AGM-84E empty ship missile. The projectile is guided by GPS/INS combined guidance Segment guidance, infrared imaging plus video data link remote control for terminal guidance, was launched in the Gulf War in early 1991 Its high hit accuracy achieved noticeable success. After the Gulf War the bomb - "improved sensitivity to slam" (SLAM-ER) AGM-84H and "Dasilamu" (Grand SLAM) air to ship missile, midcourse guidance are used GPS/INS integrated guidance. A new generation of airborne precision guided air to ground weapons, which have adopted GPS/INS integrated guidance technology, are: AGM-86C air in the United States Shoot off cruise missiles, AGM-130 ground to air missiles, AGM-142 ground to air missiles, and CBU-97/B sensors to detonate (SFW) Bombs and GBU-29/31 "Jadam" (JDAM) guided bombs. "Jay Damm" is carried by the B-2A stealth strategic bomber For the first time, a large number of March 24, 1999 to June 10th of Yugoslavia for 78 days of bombing, and in May 8th My Embassy in South China was brutally bombed. The combined guidance plans to add airborne precision guided weapon: AGM-154 "jesso wu" (JSOW) joint standoff weapon launching, "Jia algorithm" (JASSM) joint standoff ground missiles and "Jay Damm" (JDAM) second, third stage guided bombs, etc.. The A global positioning system (GPS) technology " The global positioning system (GPS), built in 1993, is a dual-use space for military and civilian management by the U. S. Department of Defense Radio navigation system. The utility model is composed of a navigation constellation, a ground control station and a user positioning receiver. Navigation constellation currently It consists of 24 satellites, including 21 working satellites and 3 spare satellites, which are about 20183 kilometers from the earth 6 elliptical orbital planes, with a tilt angle of 55 degrees, evenly distributed 4 satellites, with a running cycle of 12 hours / turn, and 3 satellites Covering more than the world, users can receive at least 6 satellite navigation signals all over the world at the same time, The navigation signals of 11 satellites can be received simultaneously. The ground control station is used for measuring and predicting satellite orbits The equipment on the satellite is monitored to provide the user with the location data of the satellite relative to the ground. A subscriber positioning receiver uses a satellite received from a satellite that is accurately informed of its spatial position by its ephemeris data Information transmitted at light speed, measuring the time of propagation of the information, and calculating its relative position with the satellite, i.e., distance. Using the distance triangle measuring principle, the user GPS receiver can receive the signals of 3 satellites simultaneously, and the user can be calculated The three-dimensional position of the GPS receiver; At the same time, the time is obtained by using the distance obtained in the measurement time According to the relationship between the linear velocity and the Doppler frequency, the user GPS receiver can measure the Doppler frequency of the satellite So as to calculate the speed of motion. Due to the user receiver's clock reference, relative to the GPS atom, Zhong Ji Quasi existence error, therefore, the actual measurement distance is called pseudo range (pseudo range) The velocity measurement obtained from the pseudo range differential is called the difference pseudo range (Delta) in the actual measurement interval Pseudo, range) also called pseudo range rate". To determine the three-dimensional location of the user's GPS receiver and When the clock error is calibrated, it is necessary to track the signals of 4 satellites in the GPS navigation constellation at least simultaneously Able to accomplish navigation calculation tasks. If simultaneous tracking and reception of more than 4 satellites in the GPS navigation constellation is in use The navigation accuracy of the same inertial navigation system will be higher. The Each satellite in the GPS navigation constellation is equipped with synchronized cesium (Cs133) atoms as the time standard for measuring systems A carrier transmitter for transmitting and locating signals, the carrier signal operates at 2 frequencies in the L band: L1 = 1575.42 MHz, L2 is 1227.6 MHz. The L1 carrier signal is made up of 1.023 MHz and bandwidth 1 MHz pseudo random noise The code is modulated with repeated modulation intervals of 1024 bits or 1 milliseconds. The modulation code is called "coarse intercept" (C/A) code to provide standard positioning services (SPS) for global civilian users. L2 carrier signals are adopted 10.23 MHz, bandwidth 10 MHz pseudo random noise coded modulation, repeated modulation interval of 7 days, The modulation code, called P, provides precise positioning services for the United States and its allies and military users" (PPS). Satellite navigation signal transmission rate of 50 bit / sec, L1 and L2 carrier signal except carrier navigation Apart from information, there are data bits that describe satellite orbits, clock calibrations, and other system parameters. To prevent civilian C/A code GPS receivers from being used for military purposes, the U.S. Department of defense introduced the selection availability (SA) Technology, that is, at the performance level of the existing C/A code GPS receiver, a human error of approximately 0.2 ms of quivering noise Adding to the clock signal causes the received positioning signal deviation to increase at a speed of 0.46 meters per second to make its positioning accuracy Drop to about 100 meters. To prevent enemy interference, encryption of P code is also made to work on AS The password file is updated regularly, and the encrypted P code is formally called Y code, often referred to as P (Y) code. Only add A military GPS receiver with a secure AS module can normally receive P (Y) code signals, with a positioning accuracy of about 20 meters. The repetition time between the P (Y) code and the C/A code is 7 and 1 ms, and the P (Y) code is more than the C/A code The code is much longer, and C/A code is easy to intercept, and P (Y) code is almost impossible to intercept without auxiliary measures. therefore The military GPS receiver must first receive the C/A code signal, and obtain the signal needed to capture the P (Y) code quickly The "shift" (HOW) information, Then the receiver can receive the P (Y) code signal. At the same time, due to the L1 carrier C/A Code modulation amplitude is greater than L2 carrier P (Y) code modulation range, and military GPS receiver can be eliminated from 2 frequency measurements In addition to the positioning errors caused by the ionosphere and the troposphere, the positioning accuracy is increased to about 18 meters. Influence GPS receiver The main error sources of positioning accuracy are space segment, system section and user segment, mainly including ionosphere propagation delay and Flow propagation delay, the latter includes satellite clock, satellite ephemeris, receiver and so on. At present, the satellite clock is reduced and Ephemeris error methods are mainly wide area GPS enhancement (WAGE), differential GPS (DGPS) and relative GPS RGPS), etc.. Two, inertial navigation system (INS) technology Inertial navigation system (INS) is an autonomous space reference maintenance system, which consists of an inertial measurement unit and a control display system Device, state selection device, navigation computer and power supply. The inertial measurement unit consists of 3 accelerometers and 3 Gyroscope. The former is used to measure the acceleration of the 3 translational motion of the vehicle, indicating the direction of the local vertical The angular displacement of the 3 rotational motion of a carrier is used to indicate the direction of the earth's rotation from the shaft. Measured acceleration A two integral is used to calculate the position of the launcher in the selected navigation reference coordinate system. The According to the installation method of inertial measurement unit on launch vehicle, it can be divided into two kinds of inertial navigation system, platform type and strapdown type. Platform inertial navigation system is to install accelerometers and gyroscopes on inertial navigation platform, which is different according to setting coordinate system It can be divided into spatial stability and local inertial navigation system. The inertial platform of the former is relatively inertial and the space is stable, The inertial platform of the latter can track the local horizontal surface, but its orientation relative to the earth can be fixed or free Wandering. Because the platform can isolate the vibration of the carrier, the working condition of the inertial instrument is better, and the measurement error can be reduced The navigation accuracy is improved, but the structure is complex, the volume is large, and the cost is high. Strapdown inertial navigation system (SINS) is an accelerometer The gyroscope is mounted on the carrier, and a mathematical platform is established by computer software to replace the mechanical inertial platform The utility model has the advantages of simple structure, small size, light weight and low cost, but the working condition of the inertial instrument is poor, and the measuring error is increased and the navigation is guided The accuracy of the gyroscope is very high, so it is capable of shock, vibration and angular velocity measurement Gyroscope, laser gyro, fiber optic gyroscope and other new gyroscope are ideal. The first weapons guided by the inertial navigation system were the V-2 ground to ground ballistic missiles of fascist Germany during the two World War . Most of the long-range missiles developed after the war adopted inertial navigation system as midcourse guidance or whole course guidance As far as tactical missile is concerned, strapdown inertial navigation system is widely used as guidance system. The main advantage of an inertial navigation system is that: Capable of independently navigating without relying on any outside system, providing continuous, including attitude, benchmarks The overall navigation and guidance parameters have good short term accuracy and stability after alignment. The main disadvantages are as follows: structure reconstruction The cost of navigation is higher, and the navigation error increases with time. The time of heating and alignment is long, so it can not satisfy the requirement of far Requirements for long range or long range navigation and high precision navigation or guidance. In order to improve the navigation and positioning accuracy, a variety of Integrated navigation means matching different types of navigation systems with different characteristics so that they can learn from each other, Thus forming a better new navigation system - integrated navigation system, such as inertial navigation and Doppler combination guidance Navigation systems, inertial navigation and direction finding / range finding (VOR/DME) integrated navigation systems, inertial navigation and Loran (LORAN) Decca or (DECCA) or (OMEGA) or omega carnsore (CONSOL) or ground reference navigation (TRN) or Shape feature matching (TCM) integrated navigation system, and inertial navigation and global positioning system (INS/GPS) combined guidance Navigation system. In the integrated navigation system, the latter is the most advanced and the most widely used. The Three 、 satellite positioning / inertial navigation (GPS/INS) integrated guidance technology Inertial navigation and satellite positioning (INS/GPS) integrated navigation system is used for weapon guidance, which can give full play to both Advantage and learn from each other, using GPS long-term stability and moderate precision, to make up for the error of INS spread over time or To increase the disadvantages, we can make use of the short-term high precision of INS to make the GPS receiver lose or increase the error when it is disturbed Further more, the strapdown inertial navigation system has the advantages of simple structure, high reliability, small size and heavy weight With the advantages of light weight and low cost, the GPS receiver antenna is improved by means of attitude information and angular velocity information of INS The directional manipulation capability enables rapid capture or recapture of GPS satellite signals, while simultaneously providing high levels of GPS Accuracy, position information and velocity information are used to estimate and correct inertial navigation system position errors, velocity errors, and other system errors The invention realizes the alignment and calibration of air transfer through differential parameters so as to relax the requirements of the accuracy of the air transfer Integrated guidance system to achieve the optimization, with high efficiency cost ratio. The key components of the GPS/INS combination are the Calman filter as the interface and the data fusion function. Calman filtering by R.C. Calman and R.S. and in early 1960s, in order to meet the application of high speed data A new class of linear filters is proposed for the computation of man-made satellite orbits and navigation by word type computers Models and methods are generally known as Calman filtering. Using Calman filter, the error of inertial navigation system, gyro The random drift and accelerometer errors are listed as state variables, and the discretized state equations are listed A statistical mathematical model is then used to describe the satellite positioning / inertial navigation (GPS/INS) using this equation of state and measurement equations The dynamic characteristics of the composite system are handled by the filter equation, and the optimal estimation of the system state variables is given According to the optimal estimation of these errors, the ins are corrected synthetically so that the navigation error of the combined system is minimum . Since the Calman filter is a recursive linear minimum variance estimator with bias, the mean of its estimation error is considered Or its mathematical expectation is zero, therefore, the GPS/INS composite system is the optimal integrated guidance system. GPS/INS combination The method is divided into two kinds according to the configuration of Calman filter: loose coupling (also called serial coupling), that is, each has 1 Calman filter. Tight coupling, that is, share 1 Calman filters. The two combinations have their advantages and disadvantages From the point of view of accuracy, the method of tight coupling is usually adopted. The main key technologies of GPS/INS integrated guidance are: GPS receiver technology, mainly high efficiency and low cost device technology Operation. INS technology includes a variety of new inertial sensor technologies, such as laser gyro, fiber optic gyroscope, hemispherical resonator, etc. Screw, and all kinds of micro electro mechanical manufacturing technology. GPS/INS coupling technique, including Calman filtering, collocation and error estimation Values, techniques, etc. GPS/INS airborne / missile borne integrated technology, including airborne / missile borne GPS/INS transfer alignment, GPS/INS conversion, relative GPS pointing and attack, GPS/INS modeling and precision analysis, etc.. GPS interference and anti dry Jamming technology, including interference and anti-interference technology of GPS receiver, encryption and decryption technology, precision compensation technology and so on.