专业英语第2专题-JDAM 电路

1、Automation Speciality English自动化专业英语 杨金显Topic 2JDAM(Joint Direct Attack Munition )Electric Circuit Theory-4.1 Fields,Circuit and Circuit ParametersElectronic Technology-5.1 Signal Processing Power Electronic TheoryTranslating Skills-Converting of Word ClassLow-Drag General Purpose Bomb，LDGP Mk-82AGM

2、-154A（Joint Standoff Weapon, JSOW） Unretarded Retarded Nose fuse Collar Link Plunger Support BladeShock assorberClevis Fin release bandSuspension lugFin release wireElectrical receptacle laser-guided bombLaser seekerLaser-guided bomb A laser-guided bomb (LGB) is a guided bomb that uses semi-active l

3、aser homing to strike a designated target with greater accuracy than a gravity bomb. LGBs are one of the most common and widespread guided bombs, used by a large number of the worlds air forces. Laser-guided munitions use a laser designator to mark a target. The reflected laser light (sparkle) from

4、the target is then detected by the seeker head of the weapon, which sends signals to the weapons control surfaces to guide it toward the designated point. Laser-guided bombs are generally unpowered, using small wings to glide towards their targets. Laser-guided bombLaser Guidance PrincipleDevelopmen

5、t Laser-guided weapons were first developed in the United States in the early 1960s. The United States Air Force issued the first development contracts in 1964, leading to the development of the Paveway series, which was used operationally in Vietnam starting in 1968.Although there were a variety of

6、 technical and operational problems, the results were generally positive. LGBs proved to offer a much higher degree of accuracy than unguided weapons, but without the expense, complexity, and limitations of guided air-to-ground missiles. The LGB proved particularly effective against difficult fixed

7、targets like bridges, which previously had required huge loads of dumb ordnance to destroy. The most dramatic example was the Thanh Hoa Bridge, 70 miles south of Hanoi, a critical crossing point over the Red River. Starting in 1965, U.S. pilots had flown 871 sorties against it, losing 11 planes with

8、out managing to put it out of commission. In 1972 the Thanh Hoa bridge was attacked with Paveway bombs, and 14 jets managed to do what the previous 871 had not: drop the span, and cut a critical North Vietnamese supply artery.Development Third and fourth generation of laser-guided bombs The GBU-24 a

9、s the representative of the third generation of laser-guided bombs, the main features of Paveway III is the use of scanning, presetting and automatic tracking seeker, and the use of digital data processing systems and with different weather vane seeker. Focus of the fourth generation of laser-guided

10、 bombs is to improve the purely short-range problem and the need for designation.On the basis of the semi-active laser, the increase of GPS / INS mode improves extended-range glide for bomb to achieve standoff launch.GBU-28、The Guided Bomb Unit 28 (GBU-28) is a 5,000 pound (2,268kg) laser-guided “bu

11、nker busting” bomb nicknamed “Deep Throat” ，burrowing into the ground 6 meters of reinforced concrete, or 30 meters of soil Smart fuseGBU-57/MOP-Massive Ordnance Penetrator GBU-57/MOPMassive Ordnance Penetrator 61米混凝土或是40米的坚固岩层 Other Bombscluster bomb Cluster munitions, cluster bombs or sub-munition

12、s are air-dropped or ground-launched explosive weapons that eject smaller munitions: a cluster of bomblets. The most common types are designed to kill enemy personnel and destroy vehicles. Other submunition-based weapons designed to destroy runways, electric power transmission lines, disperse chemic

13、al or biological weapons, or to scatter land mines have also been produced. Some submunition-based weapons can disperse non-munitions such as leaflets.Because cluster bombs release many small bomblets over a wide area they pose risks to civilians both during attacks and afterwards. During attacks th

14、e weapons are prone to indiscriminate effects, especially in populated areas. Unexploded bomblets can kill or maim civilians long after a conflict has ended, and are costly to locate and remove.Cluster munitions are prohibited for those nations that ratify the Convention on Cluster Munitions, adopte

15、d in Dublin, Ireland in May 2008. The Convention entered into force and became binding international law upon ratifying states on 1 August 2010, six months after being ratified by 30 states;1 as of March 2011, a total of 108 states have signed the Convention and 55 of those have ratified it.Other Bo

16、mbsdepleted uranium bomb Other BombsSDB The GBU-39 Small Diameter Bomb (SDB) is a 250 pound (113kg) guided bomb that is intended to provide aircraft with the ability to carry a higher number of bombs. Most US Air Force aircraft will be able to carry (using the BRU-61/A rack) a pack of four SDBs in p

17、lace of a single bomb of 2,000pounds (910kg).Problems and limitations The first problem is designation. To ensure accurate guidance, the target must be illuminated by a laser designator and the pilot must deliver the weapon within the weapon basket (the zone in which the weapon seeker can observe th

18、e laser target marker and the weapon has sufficient energy to guide to the target). Laser guided bombs can be launched without the laser designator turned on, in which case it will follow a ballistic path, until such time as the seeker picks up the reflected laser signal. However, if the designator

19、is turned off, the laser spot moved, the laser signal is blocked (for example by cloud or smoke), the weapons accuracy will be greatly reduced. Problems and limitations Laser illumination can be interrupted by smoke, fog, or clouds, limiting the usefulness of LGBs in poor weather or very dusty condi

20、tions. In desert warfare, such as the 1991 Gulf War, laser designation sometimes reflected off the sand, causing weapons to home on false targets. Furthermore, the need to provide designation may leave the aircraft dangerously exposed to ground fire or enemy air support. The Joint Direct Attack Muni

21、tion (JDAM) guidance kit is a low-cost guidance kit that converts existing unguided free-fall bombs into accurately guided smart weapons. Since 1998, Boeing has produced more than 195,000 JDAM tailkits. The Components of JDAMCommon low cost guidance control unit for MK-83, MK-84 sized to fit MK-82 f

22、orm factor Highly integrated tail kit enhances JDAM affordability Strakes provide maneuverable airframe and full jettison and release envelope The ComponentsThe JDAM is not a weapon; rather it is a bolt-on for unguided bombs consisting of a tail section with aerodynamic control surfaces, a strake ki

23、t, and a combined inertial guidance system and GPS guidance control unit. It is installed by Naval Aviation Ordnancemen or Air Force Munition Systems Specialists.The JDAM production team includes Honeywell Inc. (inertial measurement unit); Rockwell Collins (global positioning system receiver); HR Te

24、xtron (tail actuator subsystem); Lockheed Martin Tactical Defense Systems (mission computer); Lockely (tail fairing); Enser and Eagle-Picher (battery); and Stremel (strakes and cable cover). JDAM Guidance Kit Components of the control systemPneumaticDynamoelectricHydraulic Thermal battery BUS 1760/1

25、553 and GPSComponents of the control systemComponents of the control systemIMU- An inertial measurement unit An inertial measurement unit, or IMU, is an electronic device that measures and reports on a crafts velocity, orientation, and gravitational forces, using a combination of accelerometers and

26、gyroscopes. The IMU is the main component of inertial navigation systems. In this capacity, the data collected from the IMUs sensors allows a computer to track a crafts position, using a method known as dead reckoning.INS-inertial navigation system An inertial navigation system includes at least a c

27、omputer and a platform or module containing accelerometers, gyroscopes, or other motion-sensing devices. The INS is initially provided with its position and velocity from another source (a human operator, a GPS satellite receiver, etc.), and thereafter computes its own updated position and velocity

28、by integrating information received from the motion sensors. The advantage of an INS is that it requires no external references in order to determine its position, orientation, or velocity once it has been initialized.INS-inertial navigation system An INS can detect a change in its geographic positi

29、on (a move east or north, for example), a change in its velocity (speed and direction of movement), and a change in its orientation (rotation about an axis). It does this by measuring the linear and angular accelerations applied to the system. Since it requires no external reference (after initializ

30、ation), it is immune to jamming and deception.INS-inertial navigation system Inertial-navigation systems are used in many different moving objects, including vehiclessuch as aircraft, submarines, spacecraftand guided missiles. However, their cost and complexity place constraints on the environments

31、in which they are practical for use.Angular accelerometers measure how the vehicle is rotating in space. Generally, theres at least one sensor for each of the three axes: pitch (nose up and down), yaw (nose left and right) and roll (clockwise or counter-clockwise from the cockpit).Linear acceleromet

32、ers measure non-gravitational accelerations of the vehicle. Since it can move in three axes (up & down, left & right, forward & back), there is a linear accelerometer for each axis.A computer continually calculates the vehicles current position. First, for each of the six degrees of freedom (x,y,z a

33、nd x, y and z), it integrates over time the sensed acceleration, together with an estimate of gravity, to calculate the current velocity. Then it integrates the velocity to calculate the current position.INS-inertial navigation system INS-inertial navigation system INS-inertial navigation system Hor

34、izontalInertial guidance is difficult without computers. The desire to use inertial guidance in the Minuteman missile and Project Apollo drove early attempts to miniaturize computers.Inertial guidance systems are now usually combined with satellite navigation systems through a digital filtering syst

35、em. The inertial system provides short term data, while the satellite system corrects accumulated errors of the inertial system.INS-inertial navigation system Integrated navigation of GPS/INS The benefits of using GPS with an INS are that the INS may be calibrated by the GPS signals and that the INS

36、 can provide position and angle updates at a quicker rate than GPS. For high dynamic vehicles such as missiles and aircraft, INS fills in the gaps between GPS positions. Additionally, GPS may lose its signal and the INS can continue to compute the position and angle during the period of lost GPS sig

37、nal. The two systems are complementary and are often employed together.GPS/INS组合导航Why does call JDAM? The guidance system was perfect for the United States Air Force and United States Navy, hence the joint in JDAM. The JDAM was meant to improve upon laser-guided and imaging infrared technology for b

38、ombs, which can be hindered by bad ground and weather conditions. General Characteristics of JDAM JDAM is not intended to replace any existing weapon system; rather, it is to provide accurate delivery of general purpose bombs in adverse weather conditions. The JDAM will upgrade the existing inventor

39、y of Mk-83 1,000- and Mk-84 2,000-pound general purpose unitary bombs and the 2,000-pound hard target penetrator bomb by integrating a guidance kit consisting of an inertial navigation system/global positioning system guidance kit. The 1,000-pound variant of JDAM is designated the GBU-31, and the 2,

40、000-pound version of the JDAM is designated the GBU-32. JDAM variants for the Mk-80 250-pound and Mk-81 500-pound bombs are designated GBU-29 and GBU-30, respectively. Hard Target penetrators being changed into low-cost JDAMs included the 2,000 pound BLU-109 and 1,000 pound BLU-110. General Characte

41、ristics of JDAM When employed, these weapons have proven highly accurate and can be delivered in any flyable weather. JDAM can be launched from more than 15 miles from the target with updates from GPS satellites to help guide the weapon to the target. Laser JDAM has been integrated with the GBU-38.

42、Development History The Air Forces initial bombing efforts during 1991s Operation Desert Storm suffered for the lack of an air-to-surface weapon that could work regardless of smoke, fog, dust, and cloud cover. Research, development, testing and evaluation (RDT&E) of an adverse weather precision guid

43、ed munition began in 1992. Several proposals were considered, including a radical concept that used GPS. At the time, there were few GPS satellites and the idea of using satellite navigation for real-time weapon guidance was untested and controversial. To identify the technical risk associated with

44、an INS/GPS guided weapon, the Air Force created in early 1992 a rapid-response High Gear program called the “JDAM Operational Concept Demonstration” (OCD) at Eglin Air Force Base. Honeywell, Interstate Electronics Corporation, Sverdrup Technology, and McDonnell Douglas were hired to help the USAF 46

45、 Test Wing demonstrate the feasibility of a GPS weapon within one year. The OCD program fitted a GBU-15 guided bomb with an INS/GPS guidance kit and on 10 February 1993, dropped the first INS/GPS weapon from an Air Force F-16 on a target 88,000feet (27km) downrange. Five more tests were run in vario

46、us weather conditions, altitudes, and ranges.The OCD program demonstrated an 11-meter Circular Error Probable (CEP).Development HistoryOperational use Guidance is facilitated through a tail control system and a GPS-aided inertial navigation system (INS). The navigation system is initialized by trans

47、fer alignment from the aircraft that provides position and velocity vectors from the aircraft systems. Once released from the aircraft, the JDAM autonomously navigates to the designated target coordinates. Target coordinates can be loaded into the aircraft before takeoff, manually altered by the air

48、crew in flight prior to weapon release, or entered by a datalink from onboard targeting equipment, such as the LITENING II or Sniper targeting pods. Operational use In its most accurate mode, the JDAM system will provide a minimum weapon accuracy CEP of 13 meters or less when a GPS signal is availab

49、le, though Boeing and the Air Forces report less than 10 meters CEP in testing. If the GPS signal is jammed or lost, the JDAM can still achieve a 30 meter CEP or less for free flight times up to 100 seconds.Advantages The introduction of GPS guidance to weapons brought several improvements to air-to

50、-ground warfare. The first is a real all-weather capability since GPS is not affected by rain, clouds, fog, smoke, or man-made obscurants. Previous precision guided weapons relied on seekers using infrared, visual light, or a reflected laser spot to “see” the ground target. These seekers were not ef

51、fective when the target was obscured by fog and low altitude clouds and rain (as encountered in Kosovo), or by dust and smoke (as encountered in Desert Storm).Advantages The second advantage is an expanded launch acceptance region (LAR). Since GPS-based flight control systems know the weapon current

52、 location and the target location, these weapons can autonomously adjust the trajectory to hit the target. This allows the launch aircraft to release the weapon at very large off-axis angles including releasing weapons to attack targets behind the aircraft.Advantages The third advantage is a true “f

53、ire-and-forget” capability in which the weapon does not require any support after being launched. This allows the launching aircraft to leave the target area and proceed to its next mission immediately after launching the GPS guided weapon.Advantages Another important capability provided by GPS-base

54、d guidance is the ability to completely tailor a flight trajectory to meet criteria other than simply hitting a target. Weapon trajectories can be controlled so that a target can be impacted at precise headings and vertical angles. Advantages This provides the ability to impact perpendicular to a ta

55、rget surface and minimizing the angle of attack (maximizing penetration), detonating the warhead at a the optimum angle to maximize the warhead effectiveness, having the weapon fly into the target area from a different heading of the launch aircraft (decreases the risk of detection of the aircraft).

56、 GPS also provides an accurate time source common to all systems. This allows multiple weapons to loiter and impact targets at preplanned times and intervals.Upgrades Laser JDAM (LJDAM), as this upgrade is known, adds a modular laser seeker kit to the nose of a JDAM equipped bomb, giving the ability

57、 to engage moving targets to the JDAM. The Laser Seeker is a cooperative development between Boeing Integrated Defense Systems and Israels is called Precision Laser Guidance Set .During FY2004, Boeing and the U.S. Air Force began testing of the laser guidance capability for JDAM, with these tests de

58、monstrating that the system is capable of targeting and destroying moving targets.This dual guidance system retains the ability to operate on GPS/INS alone, if laser guidance is unavailable, with the same accuracy of the earlier JDAM.UpgradesLaser seekerUpgrades Additional growth to the JDAM low-cos

59、t family of weapons includes Laser JDAM, the incorporation of a laser sensor that improves JDAMs current near-precision accuracy to precision accuracy and facilitates prosecution of targets of opportunity (including moving targets); JDAM Extended Range (JDAM ER), the incorporation of a low-cost wing

60、 set to extend JDAMs standoff range to greater than 40 miles, and the incorporation of Laser JDAM guidance. JDAM Extended Range (JDAM ER)Homemade JDAM BombSummaryModern control system knowledgeElectric circuit theory,Electronic technology and Power electronic theoryComputer technology,Measuring tech