Inertial Reference Unit

Attitude information was presented on an Attitude Director Indicator (ADI) which received its signal from an Inertial Reference Unit (IRU) or Vertical Gyro, see Fig. 1.6. The IRU used a synchro systan to transmit attitude information based on displacement from the horizontal (see Fig. 1.7). 

There have been a very small number of incidents in passenger service that have been ascribed to software failure. The best-documented example is probably an in-flight upset on a Boeing 777 near Perth, Australia, in 2005. A contributing factor was found to be a software anomaly that allowed inputs from a known faulty accelerometer to be processed by the Air Data Inertial Reference Unit (ADIRU) (ATSB 2007). 

At 0440 26 UTC (local time 1240 26) one of the Air Data Inertial Reference Units (ADIRUs) started producing multiple intermittent spike signals, and the crew received a number of warning messages many of which were spurious and unhelpful. 

This diagram presents a much-simplified version of the A330 s Electronic Flight Control System, showing its control and protection systems architecture. Because of inadequate design analysis, a particular spike" failure mode in one single air data inertial reference unit (ADIRU) was able to lead to sudden pitch down of the aircraft when in level high-altitude cruise. 

Flight control systems require accurate angle of attack (AOA) data, which are provided by 3 redundant air data inertial reference units (ADlRUs). 

ADIRU Air Data and Inertial Reference Units Chapter 6... 

The primed co-ordinates are those in the inertial reference plane. In the calculations described in this review the atoms are assumed to have unit mass, so that the resultant eigenvalues are given by... 

Nearly every FCC unit employs some type of inertial separation device connected on the end of the riser to separate the bulk of the catalyst from the vapors. A number of units use a deflector device to turn the catalyst direction downward. On some units, the riser is directly attached to a set of cyclones. The term rough cut cyclones generally refers to this type of arrangement. These schemes separate approximately 75% to 99% of the catalyst from product vapors. 

Here i, j, k and ii, ji, ki are unit vectors in the inertial and rotating frames of reference, respectively. Performing a differentiation with respect to time we obtain for the velocity of the point p... 

As was pointed out earlier, when we have considered the physical principles of the ballistic gravimeter and the pendulum an influence of the Coriolis force was ignored. Now we will try to take into account this factor and consider the motion of a particle near the earth s surface. With this purpose in mind let us choose a non-inertial frame of reference, shown in Fig. 3.5a its origin 0 is located near the earth s surface and it rotates together with the earth with angular velocity a>. The unit vectors i, j, and k of this system are fixed relative to the earth and directed as follows i is horizontal, that is, tangential to the earth s surface and points south, j is also horizontal and points east, k is vertical and points upward. As is shown in Fig. 3.5a SN is the earth s axis, drawn from south to north, I is the unit vector along OiO, and K is a unit vector parallel to SN. 

Gravitational acceleration, g, is included to relate mass to inertial force. The conversion factor, g, was included to convert one unit system to another. The subscripts o and a refer to the organic and aqueous phases, respectively. The remaining notation is as follows ... 

Let the translative velocity (i.e., the relative movement without any rotating component) of the reference frame O relative to O be designated Vq, and the angular velocity of O relative to O denoted by ft, as sketched in Fig 7.15. In the inertial frame in which are fixed orthogonal unit vectors, we... 

Table II.3. Diagonal values of molecular susceptibilities referred to the principal inertial axis system in units of 10 S erg/(G2 mole). In each case the first reference is for the susceptibilities, the second for the structure. The local values Xaa(loc), Xbb(loc), Jfcc(ioc) have been calculated according to Eq. (11.12), using the known structure and the atom susceptibilities listed in Table II.2...

Elements of the g tensor for the rotational magnetic moment in units of the nuclear magneton and referred to the principal inertial axes from the linear and quadratic rotational Zeeman effect [1, 11] ... 

In Eq. (23), is the friction coefficient that usually appears when describing Brownian motion in velocity space (Santamaria Holek, 2005 2001), and corresponds to what is referred as a direct effect in nonequilibrium thermodynamics (de Groot Mazur, 1984). The cross coefficient = pp/pyl is related to inertial effects and pp and py denote the particle and host fluid densities, and 1 is the unit tensor. The tensor e constitutes an important result of this analysis. It corresponds to a cross effect term proportional to the gradient of the imposed velocity flow Vvq. 

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