慣性技術課件簡介

1、lecture 1 - introduction1inertial technology慣性技術慣性技術付振憲付振憲school of astronautics, hitlecture 1 - introduction2about the courseinertial navigation（慣性導航）（慣性導航）:gps（global positioning system 全球定位系統(tǒng)）全球定位系統(tǒng)）devices:q gyroscopes (陀螺儀陀螺儀)q accelerometers (加速度計）加速度計）systems:q platform inertial navigation sy

2、stems （平臺式慣導系統(tǒng)）（平臺式慣導系統(tǒng)）q strapdown inertial navigation systems （捷聯(lián)慣導系統(tǒng)）（捷聯(lián)慣導系統(tǒng)）lecture 1 - introduction31.0 navigationnavigation- providing information about vehicles motion, such as position, velocity and attitude.relationship between - navigation, guidance, and controlcontrolleractuatorpositionve

3、locityattitudenavigationlecture 1 - introduction41.1 types of navigationq landmark navigationsince primitive ancient time (not limited to human beings)q astronomical navigationby observation of celestial bodies, such as sun, stars, planets or the moonlecture 1 - introduction51.1 types of navigationq

4、 satellite navigation gps, glonass, galileo, bei dou (northern star) q dead reckoning navigation (dr 定位推算定位推算)current position = initial position + covered displacementinertial navigation system (ins)lecture 1 - introduction62.1 inertial navigation: inertiainertiathe tendency of a physical object to

5、 remain still or continue moving, unless a force is applied to it - collins dictionary.q inertia of mass point - massq inertia of rigid body - angular inertia （轉(zhuǎn)動慣量）（轉(zhuǎn)動慣量）lecture 1 - introduction72.2 newtons lawsinertial navigation and newtons laws q 1st law: inertial lawq 2nd law: maf dynamic equat

6、ionq 3rd law: action and reaction inertial navigation is based on the measurement of vehicles acceleration ( using accelerometers - 加速度計加速度計).mfa/amsensitivity axisinfluence of gravitationlecture 1 - introduction82.3*basic idearelationship between position, velocity and acceleration :dtdsv dtdva tad

7、tvv00tvdtss00characteristics of inertial navigation: q autonomous (自主自主 self-contained)q no external information is requiredq relying merely on inertial measurement of the the vehicleq continuous and robust output lecture 1 - introduction92.4 two-dimensional case planar (two-dimensional) navigationv

8、ehicleplatformoutputs of accelerometers are integrated twice to obtain position of vehicle.acc. xacc. yxayaxa xv xs ya yv ys q during navigation, the platform need to track the oxy frame.q stabilization of the platform is achieved with help of gyroscopes (陀螺儀陀螺儀). platform or strapdownlecture 1 - in

9、troduction103.1 gyroscope general concept from ancient greek: : rotation sensor traditional conceptgyro: spinning rigid body gyroscope: gyro + suspension, so as to measure rotationtoy gyro: q spinning axis tends to be stableq stability is prone to disturbance disturbance factors q friction q unbalan

10、celecture 1 - introduction113.2 suspensioninnovation of suspension -gimbals(框架框架) outer ring axisouter ring inner ring inner ring axisrotor axisrotorbaseequivalent supporting point degree of freedom (dof) - the rotors- the spinning axis2-dof gyroscope (spinning axis) rotoraxisrotorbaseinnerringinner

11、ringaxis1-dof gyroscopelecture 1 - introduction123.3 drift and drifting rate q drift - change of orientation of gyros spinning axis with respect to inertial space due to disturbanceq drift rate - angular rate of drift （deg/h）drift (漂移漂移) and drifting rateq precision of navigation - inertial grade: 0

12、.01deg/h有害力矩有害力矩q history of gyros - reducing detrimental torques and driftlecture 1 - introduction134.0 history of gyrobohnenbergers machine, 1813lecture 1 - introduction144.0 history of gyro work of foucault (傅科傅科)french physicist (1819-1868)to verify the spinning of the earthfoucault pendulum(185

13、1)l = 67mm =28kgd = 6mpantheon in parislecture 1 - introduction154.1 foucaults workfoucault gyroscope (1852)earthexperiment not successful later improvementslecture 1 - introduction164.2 history: marine applicationq magnetic compass (羅盤羅盤) was applied in early marine navigationq late 19th century, r

14、eplacement of wooden-hull ships by iron-hull ones made magnetic compass less useful. q limitation on magnetic compass near the polesq searching for new direction indicatorslecture 1 - introduction174.2 history: gyro compassgyro was a promising candidate, but with problem finding local north.in 1908,

15、 gyro compass was invented by anschutz (germany) in 1909, sperry invented gyro compass too. burgeoning(發(fā)端發(fā)端) of modern application of gyroscopic techniqueslecture 1 - introduction184.3 history: aerial navigationq since 1920s, application in airplanes attitude of aircraftsazimuthrolling pitching q gy

16、ro horizonq azimuth indicatorlecture 1 - introduction194.4 history: early missilesq 1930s, pioneering study by goddard (us)q 1940s, v-1、v-2 v-1: cruising missile (1942)massively used in wwiisince june, 1944，10500 launched.v-2 : ballistic missile 1700 launchedlecture 1 - introduction204.5 history: co

17、ld war competitionafter wwii，german experts shifted to us and ussr (van braun)competition between us and ussrsputnik i, 1957explorer i, 1958braunlecture 1 - introduction214.5 history: fluid suspensionearly 1950s，fluid suspension gyroscope was developed by draper lab, mitrotorinner ring(gyro chamber)

18、outer ringlecture 1 - introduction224.6 history: journey of argonaut1958，journey of argonaut submarinepearl harbor - bearing strait - north pole - portland 21days，15000 km marking the maturity of inertial navigation lecture 1 - introduction235.0 two trendstwo trends： q higher precisionq lower cost a

19、nd size (for sins)5.1 higher precisionimproved gimbal suspension - fluid, gas, magneticachieving 10 e-7 deg/h lecture 1 - introduction245.1 higher precision: esgelectrically suspended gyro (esg)：using non-contact suspension ceramichullsphericalrotorspinningaxissphericalelectrodesti ionpumpq proposed

20、 in 1952 (nordsieck)q application in late 1970sq achieving 10e-7 deg/h q 10e-11 deg/h by stanforddisadvantages：complexity and costlecture 1 - introduction255.2 lower cost and sizering laser gyro (rlg 環(huán)形激光陀螺環(huán)形激光陀螺) developed since early 1960s, applied in 1970sfiber optical gyro (fog 光纖陀螺光纖陀螺)develope

21、d since 1970s, applied since early 1980slecture 1 - introduction265.2 fiber optical gyro (fog)developed since 1970s, applied in early 1980sfogs rapid increase in use mech.rlgfoglecture 1 - introduction275.2 vibratory gyrovibratory gyros (振動陀螺振動陀螺)q tuning fork (音叉音叉)q piezoelectric gyro (壓電壓電)q hemi-