RU2239160C1 - Orientation system - Google Patents

Abstract

FIELD: devices for measurement of angles of orientation of flying vehicles and transport facilities.

SUBSTANCE: proposed orientation system includes gyro vertical for measurement of bank and pitch angles, directional gyroscope for measurement of heading angle, three-component meter for measurement of angular velocities and three-component meter for measurement of phantom acceleration. Signals corresponding to bank, pitch and heading angles which are converted in analog-to-digital converter are subjected to processing by quaternion conversion unit which calculates quaternion orientation. Magnitude of quaternion thus calculated is furnished to inputs of correction on/off switch unit and error identification unit; then signals from correction on/off switch unit are furnished to orientation quaternion calculation unit whose other inputs receive signals from output of error identification unit and signals corresponding to three components of angular velocity and three components of phantom acceleration. Orientation angle calculation unit calculates bank, pitch and heading angles.

EFFECT: enhanced accuracy and reliability of determination of orientation angles.

1 dwg

Description

The invention relates to devices for measuring the orientation angles of aircraft, as well as land vehicles and other moving objects (ON).

Gyroscopic orientation systems [1, 2] of aircraft are known. Widely used are orientation systems based on gyroscopic course vertical [2]. It contains a biaxial platform stabilized in the horizon plane according to the signals of a pair of two-stage gyroscopes and two liquid pendulum sensors. The heading gyroscope is mounted on the outer (roll) frame of the biaxial stabilizer, and is also connected by a thrust to the inside, which ensures the vertical axis stabilization of the axis of the outboard heading gyro. The disadvantage of the described orientation system is the rather large mass (> 8.5 kg) and high cost, which is unacceptable for small-sized aircraft.

Orientation systems based on triaxial gyrostabilizers are used [1]. Their disadvantage is also the large mass, dimensions and cost. Known orientation systems of spacecraft (Pelpor D.S. Gyroscopic systems of orientation and stabilization. - M .: Mechanical Engineering. 1982. - 166 p.), Containing gyroorbitant in the form of a three-degree gyroscope in a gimbal and infrared vertical (p.135-139) . The disadvantage of such an orientation system is the presence of cardan errors in the gyro-orbiter when the spacecraft deviates from the horizon plane.

A known orientation system containing a pair of three-stage gyroscopes: gyrovertical and course gyroscope (prototype) [1]. The gyrovertical is a three-stage astatic gyroscope having ball-bearing supports in the suspension axes of the outer and inner frames. Two liquid pendulum sensors are installed on the inner frame, which respond to the gyroscope deviation in two mutually perpendicular directions. The electrical outputs of these sensors are connected to the control windings of the sensors of the moments of horizontal correction. The combination of two liquid pendulum sensors and two moment sensors forms a horizontal correction system. Along the suspension axes of the outer and inner gyro frames, roll angle and pitch sensors are installed, usually of a transformer type. The roll sensor usually has a software device (in the form of a base located on the body and rotated by the engine). The course instrument is also a three-stage gyroscope, the axis of the outer frame of which is parallel to the normal axis of the software. The gyroscope also has a ball-bearing suspension, on the inner frame of which there is a liquid pendulum sensor, its output is connected to the control winding of the torque sensor, which creates a moment around the suspension axis of the outer frame. The liquid pendulum sensor and the moment sensor form a horizontal correction system that holds the axis of proper rotation of the directional gyroscope in the horizon plane. The signal pick-up sensor is, as a rule, a transformer angle sensor that detects the rotation of the outer frame relative to the base of this sensor located on the housing. The base has a drive in the form of an engine, which can deploy it relative to the housing at a program angle. The orientation system may include a correction switch, power sources, and other devices necessary to ensure its operation. The orientation system works as follows. Before the movement, the axis of its own rotation of the gyrovertical takes a vertical position, and in the directional gyroscope - horizontal. Using a software device, the program angle of the course is set. When a software moves, its turns occur relative to the horizon plane and a given direction of movement along the course. These turns are recorded by the corresponding gyroscopes, converted by angle sensors into electrical signals, and the latter are fed into the control and navigation system. The orientation system is compact and light in mass; it is widely used in the form of, for example, MGV-4 and GA-8 and other systems.

The disadvantage of this orientation system is the presence of cardan errors in the course gyroscope, which can reach values of 8-10 ° at a roll angle of 30 ° and a pitch of 10 °. In addition, cardan errors can also occur in the gyro-vertical if the axis of the suspension of its outer frame is directed along the transverse axis of the object. This reduces the accuracy of control, and also reduces the stability of the system of the aircraft - autopilot.

The task of the invention is to improve the accuracy and reliability of information retrieval in the channels of the orientation system. The problem is solved due to the fact that three angular velocity sensors with sensitivity axes parallel to normal, transverse and longitudinal are introduced into the orientation system, which consists of a gyro vertical and a direction gyro installed on a moving object and containing signal pick-up sensors at the corners of the log, roll and course axes of the object, three accelerometers with similarly directed sensitivity axes, as well as an on-board computer with an analog-to-digital converter. The outputs of the directional gyroscope, gyro vertical, three angular velocity sensors and three accelerometers are connected through the inputs of a multi-channel analog-to-digital converter (for example, a 16-channel 16-bit PCL-816 ADC board) with the corresponding inputs of the on-board computer.

и углу тангажа

, и гироскопа направления 2, выдающего сигнал по углу курса

. В систему ориентации также входят трехкомпонентный измеритель угловых скоростей (ТГИУС) 3 и трехкомпонентный измеритель кажущегося ускорения (ТИКУ) 4, которые вырабатывают в виде напряжения постоянного тока сигналы трех составляющих угловой скорости в проекциях на оси объектовой системы координат

,

,

и трех составляющих кажущегося ускорения в проекциях на те же оси

,

,

, которые преобразуются аналого-цифровым преобразователем (АЦП) 5. Преобразованные сигналы, соответствующие углам крена, тангажа и курса, обрабатываются блоком кватернионных преобразований 6, который вычисляет кватернион ориентации ПО. Вычисленное значение кватерниона поступает на входы блока включения и выключения коррекции 7 и блока идентификации погрешностей ТГИУС и ТИКУ 8, с выхода блока включения и выключения коррекции 7 - на вход блока вычисления кватерниона ориентации 9, на другие входы которого поступают сигналы с выхода блока идентификации погрешностей 8 и сигналы с шести выходов АЦП 5, соответствующие трем компонентам угловой скорости и трем компонентам кажущегося ускорения. С выхода блока вычисления кватерниона ориентации 9 кватернион ориентации ПО поступает на вход блока вычисления углов ориентации 10, с выходов которого выдаются сигналы, соответствующие углам крена, тангажа и курса ПО. Блоки 6-10 входят в состав бортового компьютера (БК), в качестве которого может быть применен специализированный вычислитель, например на основе микропроцессоров 1834ВМ86 или 1821ВМ85. В качестве гировертикали 1 (ГВ) может быть применен прибор МГВ-2 или МГВ-4, в качестве гироскопа направления 2 (ГН) - прибор ГА-6 или ГА-8, в качестве датчиков ТГИУС 3 - приборы ДУСВЧ или другие (ВГ910 и ВГ951), а в качестве датчиков ТИКУ 4 - акселерометры ДЛУММ-3, 5, 10 и т.д. Отметим, что введение ДУСов и акселерометров в систему ориентации не приводит к увеличению массы пилотажно-навигационного комплекса летательного аппарата: эти приборы уже имеются в его системе управления и используются по другому назначению.The orientation system, the diagram of which is shown in the drawing, consists of a gyro-vertical 1, which measures and issues signals to the control system along the roll angle

and pitch angle

, and the gyro of direction 2, which gives a signal along the angle of the course

. The orientation system also includes a three-component angular velocity meter (TGIUS) 3 and a three-component apparent acceleration meter (TIKU) 4, which produce signals of the three components of the angular velocity in the projections on the axis of the object coordinate system as DC voltage

,

,

and three components of the apparent acceleration in projections on the same axis

,

,

, which are converted by an analog-to-digital converter (ADC) 5. The converted signals corresponding to the angles of pitch, pitch and course are processed by the quaternion transform unit 6, which calculates the quaternion of the software orientation. The calculated value of the quaternion goes to the inputs of the on and off correction unit 7 and the error identification unit TGIUS and TIKU 8, from the output of the on and off correction unit 7 to the input of the orientation quaternion calculation unit 9, the other inputs of which receive signals from the output of the error identification unit 8 and signals from the six outputs of the ADC 5, corresponding to the three components of the angular velocity and the three components of the apparent acceleration. From the output of the orientation quaternion calculation block 9, the software orientation quaternion is fed to the input of the orientation angles calculation block 10, the outputs of which give signals corresponding to the roll, pitch, and heading angles. Blocks 6-10 are part of the on-board computer (BC), which can be used as a specialized computer, for example, based on microprocessors 1834ВМ86 or 1821ВМ85. The MGV-2 or MGV-4 device can be used as a gyro-vertical 1 (GV), a GA-6 or GA-8 device as a directional gyroscope 2 (GN), and DUSVCh or other devices (VG910 and VG951), and as sensors TIKU 4 - accelerometers DLUMM-3, 5, 10, etc. Note that the introduction of DOSs and accelerometers into the orientation system does not increase the mass of the flight-navigation complex of the aircraft: these devices are already in its control system and are used for a different purpose.

The principle of operation of the cardan errors compensation scheme is as follows. When moving software with roll and pitch angles less than the predetermined values, the heading, roll and pitch signals are removed from GV 1 and GN 2, are converted by the block of quaternion transformations of BC 6 into values of the quaternion orientation according to the algorithms:

,

,

- курс, крен и тангаж, полученные с ГН и ГВ.Where

,

,

- course, roll and pitch received from GN and HS.

For small roll and pitch angles, the software expressions (1) are entered through the on / off correction block 7 BC as correcting terms into the quaternion equation for determining orientation angles from the signals of TGIUS 3 and TIKU 4. The quaternion equation is implemented in the calculation unit of the quaternion of orientation 9 in the form following algorithm:

- кватернион угловой скорости ПО, сформированный на основе сигналов, измеренных ДУСами в проекциях на соответствующие оси,Where

- the quaternion of the angular velocity of the software generated on the basis of signals measured by the TLS in the projections on the corresponding axis,

- кватернион линейной скорости ПО, полученный по сигналам ТИКУ

в проекциях на соответствующие оси,

- software linear velocity quaternion obtained from TIKU signals

in projections on the corresponding axis,

- разность кватернионов ориентации, полученных по выражениям (1) и (2), которая запоминается в блоке идентификации погрешностей ТГИУС и ТИКУ 8 в режиме движения ПО с малыми углами крена и тангажа (меньшими 5°). Эта разность характеризует погрешности датчиков ТГИУС И ТИКУ и в случае больших углов крена и тангажа ПО используется в качестве корректирующего члена при определении кватерниона ориентации по выражению (2).

- the difference of the orientation quaternions obtained by expressions (1) and (2), which is stored in the error identification unit TGIUS and TIKU 8 in the motion mode of the software with small roll and pitch angles (less than 5 °). This difference characterizes the errors of the TGIUS and TIKU sensors and, in the case of large roll and pitch angles, the software is used as a correction term in determining the orientation quaternion using expression (2).

Expression (2) is represented in scalar form:

по алгоритмам:When the roll or pitch angles are large in advance of the specified values, the output signals at the orientation angles of the software are not taken from GN 1 and GV 2, but are calculated in the BC using the signals TGIUS 3 and TIKU 4 taking into account the value of the correction term taken from block 8

according to the algorithms:

.Where

.

The orientation quaternion obtained in block 9 in block 10 is converted into roll angles, pitch, and heading angles, which are used in the software control system. The following expressions obtained using the components of the quaternion orientation are used for the transformation:

The usefulness of this invention is determined by increasing the accuracy of the removal of orientation angles by reducing the cardan error of GN 1 and GV 2 at large roll and pitch angles by creating a second orientation channel based on TLSs that do not have cardan errors and accelerometers. So, if at a roll angle of 30 ° the cardan error in GN 1 can reach 10-12 °, then due to the application of the proposed compensation scheme, this error decreases by 10-20 times depending on the length of the turn. In this case, the errors of DOSs having a disparate angular drift velocity than GN 1 (in GA-6 it is 3 ° / hour; in GA-8 it is 1 ° / hour, while in the differential safety system is 36 ° / hour), during U-turns are eliminated by correction algorithms when moving software with small (up to 5 °) roll and pitch angles.

Sources of information

1. Pelpor D.S., Yagodkin V.V. Gyroscopic systems: Part I Design of gyroscopic systems. - M .: Higher school, 1977 .-- 216 p.

2. Gyroscopic directional gyroscopic CVG-1. Technical description. 6B2.568.004TO, 1971.- 34 p.

Claims (1)

An orientation system containing a gyro-vertical and a directional gyroscope mounted on a moving object, characterized in that three angular velocity sensors are introduced into it, the sensitivity axes of which are parallel to the normal, transverse and longitudinal axes of the object, three apparent acceleration meters with similarly directed sensitivity axes, and block of quaternion transformations, block of on and off corrections, block for identifying errors, block for calculating the quaternion of orientation, block for calculating the orientation angles and an analog-to-digital converter, while the outputs of the directional gyroscope and the vertical gyro are connected through the inputs of the multi-channel analog-to-digital converter with the corresponding inputs of the quaternion transform block, the output of the quaternion transform block is connected to the input of the on and off correction block and the first input of the error identification block, the output of the block on and off corrections - with the input of the orientation quaternion calculation unit, the other inputs of which are connected to the output of the identification unit and errors, and through an analog-to-digital converter are connected to the outputs of three angular velocity sensors and three apparent acceleration meters, and the output of the orientation quaternion calculation unit is connected to the input of the orientation angle calculation unit, and the second input of the error identification unit.