公开(公告)号：JPH102754A

公开(公告)日：1998-01-06

申请号：JP5779297

申请日：1997-03-12

Applicant: LITTON SYSTEMS INC

Inventor： TAZARTES DANIEL A ,  MARK JOHN G

IPC: G01C21/16

Abstract: PROBLEM TO BE SOLVED: To provide a method and an apparatus, based on a larger number of data samples per one updated interval in the coning compensation for a strap down inertial navigator. SOLUTION: Five groups of angles, continuously increasing in the rotation of a fixed coordinate system of a machine, are utilized as measured at a regularly accurate measuring interval by a gyroscope which is orthogonally carried. Each of the five measuring groups is obtained at a group interval, equivalent to each of the five measuring intervals. An angular displacement, compensated for the coning in a machine-fixed coordinate system, is obtained by the sum of the five increasing angles measured and a coning compensation item for a space-fixed axis at the pth group interval. Thus, the angular displacements, compensated for coning, can be totalized (p) times over a plurality of groups, to obtain a correct evaluation of a vector angle of rotation.

公开(公告)号：JP2001066323A

公开(公告)日：2001-03-16

申请号：JP2000229132

申请日：2000-07-28

Applicant: LITTON SYSTEMS INC

Inventor： TAZARTES DANIEL A ,  YOSHIDA YUMI ,  MARK JOHN G

IPC: G01P21/00 ,  G01P15/125 ,  G01P15/13 ,  H03M1/06 ,  H03M1/08 ,  H03M1/50

Abstract: PROBLEM TO BE SOLVED: To reduce a periodic low frequency noise of an output of an accelerometer by maintaining a pendulum-like mass at a zero position by using a rebalance loop. SOLUTION: In this accelerometer, plates 12, 14 form capacitors C1, C2 together with a pendulum-like mass 10, and are connected to a parallel feedback route of an arithmetic amplifier 16. Switches S1, S2 on the route are alternately turned ON according to a timing signal of a state machine 22. When the switch is turned ON, a voltage pulse 20 supplied to the amplifier 16 alternately generates a charge at the plate 12, 14. A differential sample and hold circuit 24 standardizes the voltages of both the plates, measures a difference between the voltages, and sends it to an arithmetic amplifier 28. An analog signal indicating a force for maintaining the mass 10 of the amplifier 28 '0' is compared with an output of a chopping wave generator 36, and triggers an FF 40. The FF 40 takes timing for supplying a using ratio of the rebalance in response to a pick-off signal to the plats 12, 14 by its output, and sets a position of the mass 10 to '0'.

公开(公告)号：JP2000241169A

公开(公告)日：2000-09-08

申请号：JP35038199

申请日：1999-12-09

Applicant: LITTON SYSTEMS INC

Inventor： TAZARTES DANIEL A ,  MARK JOHN G ,  TAZARTES DAVID I

IPC: G01C19/72

Abstract: PROBLEM TO BE SOLVED: To generate a pseudo-random bit sequence having improved statistical characteristics by guiding a feedback bit from each generated sequence of a P-sub-sequence, and modifying the P-sub-sequence by one or a plurality of modifier bits. SOLUTION: A feedback bit is determined from a content of a shift register of a pseudo-random sequence generator 3, and sent to an output line 7. The feedback bit is shifted in its content of a shift register by a clock signal of a clock 13, and inputted to the register through a data input line 11. Accordingly, a new bit of the pseudo-random bit sequence is outputted to an output line 5. When the content of the register is matched to a final sequence stored in a final sequence detector 15, a statistical controller 9 generates a final sequence alarm. The controller 9 is operated by a controller 17 to send a stored modified bit sequence to the register through the line 11.

公开(公告)号：JP2000241168A

公开(公告)日：2000-09-08

申请号：JP34981199

申请日：1999-12-09

Applicant: LITTON SYSTEMS INC

Inventor： MARK JOHN G ,  TAZARTES DANIEL A ,  TAZARTES DAVID I ,  WIENER DANIEL P

IPC: G01C19/64 ,  G01C19/72

Abstract: PROBLEM TO BE SOLVED: To reduce a frequency component while maintaining high self- correlation properties by selecting '0' or '1' as next bit of a modified pseudo- random bit sequence, and further selecting next bit of an initial pseudo-random bit sequence. SOLUTION: A maximum length pseudo-random bit sequence generator 11 generates a pseudo-random bit in response to a transition of a clock signal gate processed through an input line 17. This bit is sent to an output line 25 through an output line 15 and a switch 23. A route of the clock signal is controlled by an out-of-limit detector 27. If an output of an ALU(arithmetic logic unit) 29 is positive, the switch 23 is connected to a '0' voltage source 33, or if the output is negative, the switch 23 is connected to a '1' voltage source 35. An up-down counter 37 is combined with the ALC 29 and a register 39 to judge the state of an output of the detector 27. The counter 31 is eventually initialized to maintain a measured value of an arithmetic means of the bit sequence.

公开(公告)号：JP2000171259A

公开(公告)日：2000-06-23

申请号：JP34740499

申请日：1999-12-07

Applicant: LITTON SYSTEMS INC

Inventor： TAZARTES DANIEL A ,  TIPTON HOWELL J

IPC: G01C19/64 ,  G01C19/72

Abstract: PROBLEM TO BE SOLVED: To determine a number of fringes of an optic fiber gyroscope with high measurement accuracy by determining a value of a controllable parameter, and extracting the number of fringes from an output signal of a detector by utilizing the value. SOLUTION: A light source 2 supplies an appropriately coherent light beam to an optic fiber interferometer 4. The interferometer 4 divides the input light beam into two light beams and supplies the light beams to both ends of an optic fiber which are formed as coils. The light beams ejected from both ends of the optic fiber become a single output light beam, which is supplied to a detector 6. An output from the detector 6 has DC components filtered by an HPF, A/D-converted 8, and fed to a digital processor 10, whereby measurement values of speed and angle of rotation of the interferometer 4 are output. Further, the digital processor 10 generates a phase modulation generating function Φ(t), and its modulo-2π part is D/A-converted 12 and supplied to a phase modulator in the interferometer 4.

公开(公告)号：JPH11132771A

公开(公告)日：1999-05-21

申请号：JP23108598

申请日：1998-07-14

Applicant: LITTON SYSTEMS INC

Inventor： WYSE STANLEY F ,  TAZARTES DANIEL A ,  FLAMM JUERGEN K P ,  LEE CHARLES A

IPC: G01C19/5705 ,  G01C19/5776 ,  G01C19/56 ,  G01P9/04

Abstract: PROBLEM TO BE SOLVED: To effectively suppress a measurement error by notching out all feedback torque in a lump with the driven frequency. SOLUTION: An acceleration input signals is inputted to a sensor 34, and a sensor output signal is inputted to a demodulator 36. The demodulator 36 demodulates the sensor output signal with the signal cos (wDt), where wD is the driving frequency, and (t) is time. The output signal of the demodulator 36 is inputted to a servo compensator 38, the servo compensator 38 generates the measured acceleration signal, and the measured acceleration signal is inputted to a feedback loop 40. The feedback loop 40 includes a torque remodulator 42 modulating the signal with cos(wDt). The output signal is inputted to the sensor 34 to complete the feedback loop 40. Demodulation occurs inside the feedback loop 40. This system is operated when all relative motion of the standard mass of the sensor 34 is completely suppressed from Coriolis acceleration and the necessary torque is measured.

公开(公告)号：JPH10185612A

公开(公告)日：1998-07-14

申请号：JP29896097

申请日：1997-10-30

Applicant: LITTON SYSTEMS INC

Inventor： MARK JOHN G ,  TAZARTES DANIEL A

IPC: G01C21/16

Abstract: PROBLEM TO BE SOLVED: To obtain the output, which is compensated so as to reduce the sculling error to the minimum, by using a special formula so as to process a series input, which is led out per each time from the output of one or two or more acceleration meters. SOLUTION: In a strap down type navigation system, acceleration output, which shows change of machine body velocity ΔVB of a machine body coordinate from acceleration meters 18, 20, 22 per each sampling interval Δt, is utilized with computing 28, 30, 32 in a program segment 26, and process by a formula (in the formula, (k) means 0 to K-1, m=1, (j) means 1 to J, J>=2, P means integer) so as to obtain the velocity change ΔVBC, of which sculling is compensated. This velocity change ΔVBC is converted to the velocity change ΔVNC, of which sculling is compensated and which is displayed in the navigation coordinate by a program segment 34, at the same interval with the sampling interval Δt. If the coordinate is courted at the interval with integral multiples of the sampling interval Δt, an accumulator program segment or the like is provided.

公开(公告)号：WO9804884A3

公开(公告)日：1998-03-12

申请号：PCT/US9711136

申请日：1997-06-26

Applicant: LITTON SYSTEMS INC ,  MARK JOHN G ,  TAZARTES DANIEL A ,  CORDOVA AMADO ,  CHERBETTCHIAN AGOP H ,  GOLDNER ERIC L

Inventor： MARK JOHN G ,  TAZARTES DANIEL A ,  CORDOVA AMADO ,  CHERBETTCHIAN AGOP H ,  GOLDNER ERIC L

IPC: G01C19/72

CPC classification number: G01C19/722

Abstract: A gyroscope assembly (10) includes a ring-shaped fiber optic coil (14) and a coil conforming enclosure (12, 16) of high magnetic permeability ferromagnetic material. The enclosure is ring-shaped to conform with the shape of the coil, and includes a portion (22) extending within the internal hole of the coil ring. Therefore, the coil is intimately and fully encased within high magnetic permeability material. In particular, the enclosure comprises a coil supporting spool (12) and a cover (16) secured to the spool. The spool includes a base (18) which is provided with a central hole (20) and a tubular wall (22) extending perpendicularly from the base. Coil (14) is bonded to base (18). Both the spool and the cover are formed of high magnetic permeability material, and the cover is placed about the fiber optic coil and attached to the spool. The coefficient of thermal expansion material used for the spool is matched to that of the coil pack to minimize stress imposed upon the fiber. An outer shield (28), roughly cylindrical in shape, may be further attached to the outside of the inner, toroidal shield, and the two shields are separated by a layer of low magnetic permeability material, such as of low magnetic permeability stainless steel or aluminum. 00000

Abstract translation: 陀螺仪组件（10）包括环形光纤线圈（14）和高磁导率铁磁材料的线圈合格外壳（12,16）。 外壳是环形的以符合线圈的形状，并且包括在线圈环的内部孔内延伸的部分（22）。 因此，线圈密封并完全封装在高磁导率材料内。 特别地，外壳包括线圈支撑线轴（12）和固定到线轴的盖（16）。 阀芯包括设置有中心孔（20）的底座（18）和从基座垂直延伸的管状壁（22）。 线圈（14）结合到基座（18）上。 卷轴和盖都由高磁导率材料形成，并且盖围绕光纤线圈放置并连接到卷轴。 用于卷轴的热膨胀材料系数与线圈组的热膨胀系数相匹配，以使施加在纤维上的应力最小化。 大致圆筒形的外屏蔽件（28）可以进一步附接到内环形屏蔽体的外部，并且两个屏蔽件被低磁导率材料层（例如低磁导率不锈钢）分开，或 铝。 00000

公开(公告)号：WO0211282A3

公开(公告)日：2003-03-13

申请号：PCT/US0123437

申请日：2001-07-25

Applicant: LITTON SYSTEMS INC

Inventor： TAZARTES DANIEL A ,  WELKER JAMES G

IPC: H03G3/30 ,  G01C19/72

CPC classification number: H03G3/3084

Abstract: The gain of a variable gain amplifier (20) is arranged to amplify electrical signals output from a fiber optic gyroscope (12) is controlled to provides a stable AGC response irrespective of the actual gain level. A perturbation injection circuit (14) provides a perturbation signal +/-d to a phase modulator (16) connected to the fiber optic gyro (12). A perturbation compensation circuit (24) applies perturbation compensation signals to signals output from the variable gain amplifier (20) and produces a compensated signal by reducing the magnitude of the perturbation in the amplified signal output from the variable gain amplifier (20). A gain error circuit (28) connected to the perturbation signal remaining in the amplified signal after perturbation compensation. A feedback system (32, 34) provides a gain control signal to the variable gain amplifier (20) to reduce the magnitude of the gain error signal.

Abstract translation: 可变增益放大器（20）的增益被布置为放大从光纤陀螺仪（12）输出的电信号被控制以提供稳定的AGC响应，而与实际增益水平无关。 扰动注入电路（14）向连接到光纤陀螺仪（12）的相位调制器（16）提供扰动信号+/- d。 扰动补偿电路（24）对从可变增益放大器（20）输出的信号应用扰动补偿信号，并通过减小从可变增益放大器（20）输出的放大信号中的扰动幅度来产生补偿信号。 与扰动补偿后的放大信号中残留的扰动信号连接的增益误差电路（28）。 反馈系统（32,34）向可变增益放大器（20）提供增益控制信号以减小增益误差信号的幅度。

公开(公告)号：EP0797077A3

公开(公告)日：1998-11-04

申请号：EP97103952

申请日：1997-03-10

Applicant: LITTON SYSTEMS INC

Inventor： TAZARTES DANIEL A ,  MARK JOHN G

IPC: G01C21/16

CPC classification number: G01C21/16

Abstract: The invention is a method for compensating for coning in a strapdown inertial navigation system which utilizes groups of five successive incremental angles of rotation of a body-fixed coordinate system as measured by orthogonally-mounted gyros at regular measurement intervals, each group of five measurements being obtained during a group interval equal to five measurement intervals. The coning-compensated angular displacement of the body-fixed coordinate system about a fixed axis in space during a p'th group interval is obtained by summing the five measured incremental angles and a coning compensation term. The coning compensation term consists of the sum of: (1) one-half the cross-product of a first and a second vector sum, the second vector sum being the sum of the five incremental angles of rotation in a group and the first vector sum being the sum of the second vector sum over p groups; and (2) the weighted sum of three vector cross-products, the multiplier and the multiplicand of each vector cross-product being a weighted sum of five measured incremental angles. The coning-compensated angular displacement can be summed over p to obtain an accurate estimate of the vector angle of rotation over a plurality of group intervals.