公开(公告)号：JP2000275269A

公开(公告)日：2000-10-06

申请号：JP7782999

申请日：1999-03-23

Applicant: NAT SPACE DEV AGENCY ,  NAT AEROSPACE LAB ,  MITSUBISHI HEAVY IND LTD ,  TOKYO AIRCRAFT INSTR CO

Inventor： KOSAKA MASAKAZU ,  SHIGEMI HITOSHI ,  INOKUCHI HAMAKI ,  ONO MASAHIRO ,  HATA TAKESHI ,  SAITO TAKASHI ,  ENDO MASARU

IPC: G01P5/16 ,  G01P5/17

Abstract: PROBLEM TO BE SOLVED: To measure stable air data extending over a wide range of angle of attack and angle of sideslip by mixing air data obtained by a plurality of computing parts by the use of prescribed weighting factor, and outputting them as air data. SOLUTION: A first computing part 5A obtains air data from the pressure of the vertex (total pressure) of a polygonal truncated pyramid 1 detected by a pressure detecting means 3 (pressure transducer) and pressure on the respective pyramidal faces (local pressure), based on the Newton-Lapson method. A second computing part 5B obtains air data based on pressure difference of the total pressure and the respective local pressure. A mixer 5C mixes the air data obtained by the first computing part 5A and the air data obtained by the second computing part 5B by the use of a prescribed weighting factor, and outputs them as air data. Namely, in the range of large angle of attack α and angle of sideslip β, the first computing part β A is used, and when the angle of attack αand the angle of sideslip p become in the vicinity of 0 deg., the second computing part 5B is used.

公开(公告)号：JP2001242190A

公开(公告)日：2001-09-07

申请号：JP2000049666

申请日：2000-02-25

Applicant: NAT AEROSPACE LAB

Inventor： SHIGEMI HITOSHI ,  NAKATANI TERUOMI ,  SHINDO SHIGEMI ,  TAKIZAWA MINORU ,  ONUKI TAKESHI

IPC: G01P5/175 ,  G01L7/00 ,  G01P5/16 ,  G01P5/165 ,  G01P13/02

Abstract: PROBLEM TO BE SOLVED: To provide an arithmetic processing algorithm for accurately performing arithmetic processing of flight velocity vector for indicating the level of velocity and an air flow angle and a static pressure for indicating altitude with a high update rate, in a wide-speed region from low speed to ultra-high speed in a flight velocity vector measurement system, using Pitot tube of a quadrangular pyramid type five-hole probe. SOLUTION: In the arithmetic processing algorithm, an approximation expression for obtaining an elevation angle α and a side slip angle β is expressed by a third-order polynomial for an elevation angle pressure coefficient Cα having a known number and a sideslip angle pressure coefficient Cβ, and each coefficient is expressed by a polynomial expression up to fifth order, regarding Mach number that can be calculated from a look-up table, the coefficient of the polynomial expression and the elevation angle α and the sideslip angle β can be calculated through simple arithmetic processing, by instantly inputting a known number into the approximation expression for making specific, and the Mach number can be calculated instantly from the lookup table by making specific a Mach pressure coefficient CM and an air flow angle pressure coefficient Cγ, and at the same time a wide-speed-region flight velocity vector measurement can be executed with a high update rate.