PRINCIPLES OF NAVIGATION INSTRUMENT MAKING IN CIVIL AVIATION

Abstract

The article presents the results of the development of an integrated meter angular motion parameters of small aircraft and gliders – coursehorizon. His design scheme was selected, the main measurement errors were calculated and analyzed. The assembly drawing of coursehorizon, his detailed drawings and the kinematic scheme were developed. The magnetic heading channel calculation was conducted, especially the coil parameters of the suspension. Also the channel error study in standard mode was conducted and a visual simulation of coursehorizon in Simulink environment was made. 

Coursehorizon is a device that is used on light aircraft (on heavy aircrafts as a backup device). Its ability to work without external energy sources gives it an advantage over many devices such as small size, light weight (given the lack of energy), an unlimited period of operation and the ability to be installed on any aircraft (single cases in which coursehorizonis mounted on ground vehicles) [8].

The coursehorizonhas proved in practice to be a high-performance and high-precision instrument that offers many advantages such asthe ability to maintain its position in space and to perform complex bends. His extraordinary physical properties combined in 4 cylindrical magnets, which do not allow the pilots of aircrafts to stray off course. Also this device is a pointer to the angles of inclination of the roll and pitch of the aircraft[6].

Coursehorizon relates to measuring technique. The device is designed for installation on light aircraft (mainly hang-gliders, motor hang-gliders, light single-engined planes). It can be used to measure angles and directions to the north, as well as to indicate the spatial position of the object.

Devices of this type are not very accurate, but they do not require power sources and their operation based on the use of the magnetic field of the Earth. According to this coursehorizoncan be used as a backup device. Another significant disadvantage is the limitation of angle measurement, therefore the aircraft with this unit on board can not perform complicated bends [5].

The aim of research was to develop a constructive scheme, to calculate and analyze the basic errors of coursehorizonmeasurement as the main navigation device of light aircraft in civil aviation.

Materials and methods of research. During the level flight under the effect of the stabilizing effect of the pendulum, the pendulum has a lower gimbal (conventionally reflected), the axis of suspension of the inner frame and the outer frame are in the horizontal plane, and the permanent magnets compass rose deployed along the magnetic meridian of the Earth. At the same time is counted zero bank angle on the central index of zero pitch angle and the current angle rate [1].

During of inclination of the object, for example, to the right, sizing and flight to the South, front part will look as follows: roll index will show the value of inclination relative to heel marks on the scale; central index, silhouette-airplane will show pitch deviationrelative to pitch marks and the deviation of the course relative to the magnetic meridian [4].

Results and discussion. In order to determine errors, we have used the expression for the magnetic moment where all the moments were equated to zero. For arbitrary angles φ and β we obtain:

The schedule calculated according to the equation coincides with the theoretically calculated and reflected schedule in Figure 1. The difference is thatthe calculated schedule also pointed out the error of the compass card capture of αa liquid [2].

Fig. 1 The dynamic error of liquids capture

Conclusions

The following conclusions can be made on the basis of calculation parameters ofcoursehorizon and analysis of its errors:

1)                    theequation of error of gimbal device was obtained. It is directly based on complex mathematical model, which coincides with those given in the literature. In contrast to the well-known equations, it characterizes the interactions of forces in the channel magnetic heading;

2)                    the dynamic error of magnetic channel for pitching base was examined. It is shown that this error depends significantly on the dynamic properties of the magnetic channel, which is actually a high-pass filter to external disturbances. The equation of the coefficient of friction of the dynamic error has been got;

3)                    a visual simulation of the behavior of the magnetic channel was conducted. The simulation results coincide with the theoretical calculations.