阅读说明：本技术 一种常值加速度引起的陀螺加速度计输出测定方法 (Gyro accelerometer output determination method caused by constant acceleration ) 是由 魏宗康 于 2020-12-11 设计创作，主要内容包括：本发明提供了一种常值加速度引起的陀螺加速度计输出测定方法,根据常值输入加速度a-x、Y-0轴和Z-0轴的横向加速度以及不垂直角度β的大小,采用不同的输出模型,计算出陀螺加速度计的真实输出,输出值不仅包括输入轴加速度的相关项,还包括由于常值横向加速度作用时引入的误差项。相比现有的只考虑输入加速度作用时的线性输出计算方法,本发明的陀螺加速度计测定方法还考虑了横向加速度作用时引入的误差项,更准确、更全面、适用性更广。(The invention provides a method for measuring output of a gyro accelerometer caused by constant acceleration, which is used for measuring the output of the gyro accelerometer caused by the constant acceleration according to the constant input acceleration a x 、Y 0 Axis and Z 0 Transverse acceleration of the shaft And the magnitude of the non-vertical angle beta, calculating the real output of the gyro accelerometer by adopting different output models, wherein the output value not only comprises the relevant item of the acceleration of the input shaft, but also comprises the introduction of the constant transverse acceleration under the action of the constant transverse accelerationThe error term of (2). Compared with the existing linear output calculation method only considering the action of the input acceleration, the gyro accelerometer measuring method also considers the error term introduced when the transverse acceleration acts, and is more accurate, more comprehensive and wider in applicability.)

1. A method for measuring the output of a gyro accelerometer caused by constant acceleration is characterized by comprising the following steps:

step (1), measuring a coordinate system OX of the gyro accelerometer fixedly connected with the base₀Y₀Z₀Constant input acceleration a_xAnd constant lateral accelerationWherein, a_xAnd OX₀Are in the same direction and are in the same direction,and OY₀Are in the same direction and are in the same direction,and OZ₀Are consistent in direction;

measuring a non-vertical angle beta of an outer frame shaft and a rotor shaft of the gyro accelerometer;

step (3) according to Y in step (1)₀Axis and Z₀Constant transverse acceleration of the shaftTo determine the resultant accelerationAnd OY₀The included angle gamma of the shaft satisfies:

at this time, at Y₀Axis and Z₀Constant transverse acceleration of the shaftThe differential equation of the gyro accelerometer in action is as follows:

in formula 6, m is the eccentric mass of the rotor, l is the eccentric distance of the rotor, H is the angular momentum of the instrument rotor, alpha is the rotation angle of the outer frame relative to the instrument base, referred to as the outer frame rotation angle for short,the angular velocity of rotation of the outer frame;

step (4), setting the initial value of the outer frame angle alpha as alpha₀Calculating the output of the gyro accelerometer according to the following four conditionsNamely the angular velocity of the outer frame relative to the instrument base;

(4.1) when a_xWhen the value is equal to 0, the output value of the gyro accelerometer is as follows:

in formula 7, t is time;

(4.2) whenAnd the output value of the gyro accelerometer is as follows:

in formula 8, t is time;

(4.3) whenAnd a is_xWhen not equal to 0, the output value of the gyro accelerometer is as follows:

in the formula (9), the first and second groups,

t is time;

(4.4) whenAnd the output value of the gyro accelerometer is as follows:

in the formula (11), the first and second groups,

t is time.

2. The method for determining the output of a gyro accelerometer due to the constant acceleration according to claim 1, wherein in the step (1), the constant input acceleration a of the gyro accelerometer is_xAnd Y₀Axis and Z₀Constant transverse acceleration of the shaftThe measurement is obtained according to the measurement of 3 quartz accelerometers which are orthogonally arranged and are arranged on the inertial platform body.

3. The method for determining the output of a gyro accelerometer due to the constant acceleration according to claim 1, wherein in the step (1), the constant input acceleration a of the gyro accelerometer is_xAnd Y₀Axis and Z₀Constant transverse acceleration of the shaftThe acceleration with the amplitude less than or equal to 1g can be excited in the fixed orientation of the gravity field.

4. The method for determining the output of a gyro accelerometer due to the constant acceleration according to claim 1, wherein in the step (1), the constant input acceleration a of the gyro accelerometer is_xAnd Y₀Axis and Z₀Constant transverse acceleration of the shaftThe acceleration with the amplitude less than or equal to 1g can be excited in the fixed orientation of the gravity field.

5. The method for measuring the output of the gyro accelerometer due to the constant acceleration of claim 1, wherein in the step (1), the gyro rotor of the gyro accelerometer can be realized by dynamic pressure air flotation, liquid floating support and the like, and the yaw structure of the gyro accelerometer can be realized by an eccentric pendulum structure, a tilt-shift pendulum structure and the like.

6. The method for determining the output of a gyro accelerometer due to the constant acceleration of claim 1, wherein in the step (2), the non-perpendicular angle β between the outer frame axis and the rotor axis of the gyro accelerometer is measured by a static base optical aiming mechanism.

7. Use of the method of determining gyro accelerometer output due to constant acceleration as claimed in any one of claims 1 to 6 for error calibration of a gyro accelerometer.

Technical Field

The invention belongs to the technical field of high-precision apparent acceleration measurement, relates to accelerometer navigation calculation for an inertially stabilized platform, and particularly relates to a method for measuring output of a gyro accelerometer caused by constant acceleration.

Background

In a high-precision inertially stabilized platform, a quartz flexible accelerometer and a pendulum type integral gyro accelerometer are mainly adopted at present, the quartz flexible accelerometer and the pendulum type integral gyro accelerometer are both single-degree-of-freedom accelerometers, and each accelerometer is sensitive to the apparent acceleration in one direction.

A Pendulum Integral Gyro Accelerometer (PIGA) is a pendulum accelerometer using gyro moment for feedback, and its working principle is shown in fig. 1. In the figure, OX₀Y₀Z₀For a coordinate system fixedly connected to the outer frame, OX₀Is an input shaft; oxyz is a Leai difference coordinate system, and an Oz axis is coincident with a rotor axis;the angular velocities of the outer frame relative to the instrument base (the shell of the pendulum-type integral gyro accelerometer) and the inner frame relative to the outer frame are respectively; a is_xApparent acceleration input for the instrument along the outer frame axis; ml is the swing of the instrument along the inner frame shaft; h is the angular momentum of the meter rotor; m_xThe sum of various interference moments around the outer frame shaft; m_DIs the motor torque. The figure also comprises: 1-angle sensor, 2-amplifier, 3-torque motor, 4-output device.

As can be seen from fig. 1, such a gyroscopic accelerometer is similar in structure to a two-degree-of-freedom gyroscope: the gyro rotor is provided with an inner frame and an outer frame. An angle sensor is arranged at one end of the inner frame shaft, and an output device and a torque motor are respectively arranged at the upper end and the lower end of the outer frame shaft. Along the rotor axis Oz there is an eccentric mass m, the centre of mass of which is at a distance l from the inner frame axis, thus forming a pendulum ml around the inner frame axis.

When the instrument is along the outer frame axis OX₀Direction apparent acceleration a_xWhile, an inertia moment mla proportional to the apparent acceleration is generated on the inner frame shaft_x. Under the ideal condition, that is, under the condition of that there is no any interference moment along the inner and outer frame shafts, according to the gyro precession principle, the rotor can drive the inner and outer frames to wind OX together₀The shaft precessing at a precessional angular velocity ofAs a result of precession, a gyroscopic reaction moment is generated on the axis of the inner frameUnder steady state conditions, moment of inertia mla_xWill be precisely torqued byIs balanced, therefore, has mla_xOr is orUnder zero initial conditions, there is an ideal output value:

in order to ensure H and an outer frame shaft OX₀The gyro accelerometer is additionally provided with a servo loop, and when the gyro accelerometer is subjected to interference moment M_xWhen the angle beta of the inner frame is not 0, the angle sensor outputs corresponding voltage signals, and the voltage signals are amplified and converted and then fed to the torque motor to generate a motor torque M_DxTo counteract M_x. It can be seen that the sensor of the servo loop is an inner frame angle sensor, and the measured value is β. Although the servo loop can keep the measured value β of the angle sensor at zero, it cannot guarantee that the rotor axis Oz and the outer frame axis OX will deviate from each other when there is a mechanical zero offset of the angle sensor₀Perpendicular to each other, and for this reason such non-perpendicular angles are uniformly denoted by β. At this time, the output equation of the gyro accelerometer is:

in the formula 2, the first step is,is Y₀Axis and Z₀Constant lateral acceleration of the shaft; OX₀Y₀Z₀Is a coordinate system fixedly connected with the gyroscope accelerometer base.

The above equation 2 is a transcendental equation, and needs to be simplified to give some local qualitative analysis expressions. For example, in inertial device (below), page 197 is givenThe expression of the time T required by the accelerometer to make one precession circle under the condition is as follows:

however, the above equation has several problems:

(1) when a is_xWhen the content is equal to 0, the content,will tend to be infinite;

(2) when in useWhen the temperature of the water is higher than the set temperature,will tend to be infinite;

(3) when in useWhen the temperature of the water is higher than the set temperature,no real number solution;

therefore, the equation is only given inThe method is suitable for use under the condition.

In order to further construct a measurement error model of the gyro accelerometer and improve the use precision through error compensation, the invention provides a novel gyro accelerometer output measuring method so as to adapt to the visual acceleration precision measuring capability during the action of the transverse acceleration.

Disclosure of Invention

The technical problem of the invention is solved: the method overcomes the defects of the prior art, and provides a novel method for measuring the output of the gyro accelerometer during the action of the constant accelerometer in consideration of the constant overload application condition, such as error calibration before the gyro accelerometer is used, which is used for calculating the output value (angular velocity) of the gyro accelerometer) The value of the method not only comprises a correlation term of the input shaft acceleration, but also comprises an error term introduced when the constant value lateral acceleration acts, and the method has comprehensiveness, accuracy and universality.

The technical scheme provided by the invention is as follows:

in a first aspect, a method for determining a gyro-accelerometer output caused by a constant acceleration includes the steps of:

step (1), measuring a coordinate system OX of the gyro accelerometer fixedly connected with the base₀Y₀Z₀Constant input acceleration a_xAnd constant lateral accelerationWherein, a_xAnd OX₀Are in the same direction and are in the same direction,and OY₀Are in the same direction and are in the same direction,and OZ₀Are consistent in direction;

measuring a non-vertical angle beta of an outer frame shaft and a rotor shaft of the gyro accelerometer;

step (3) according to Y in step (1)₀Axis and Z₀Constant transverse acceleration of the shaftTo determine the resultant accelerationAnd OY₀The included angle gamma of the shaft satisfies:

at this time, at Y₀Axis and Z₀Constant transverse acceleration of the shaftThe differential equation of the gyro accelerometer in action is as follows:

in formula 6, m is the eccentric mass of the rotor, l is the eccentric distance of the rotor, H is the angular momentum of the instrument rotor, alpha is the rotation angle of the outer frame relative to the instrument base, referred to as the outer frame rotation angle for short,the angular velocity of rotation of the outer frame;

step (4), setting the initial value of the outer frame angle alpha as alpha₀Calculating the output of the gyro accelerometer according to the following four conditionsNamely the angular velocity of the outer frame relative to the instrument base;

(4.1) when a_xWhen the value is equal to 0, the output value of the gyro accelerometer is as follows:

in formula 7, t is time;

(4.2) whenAnd the output value of the gyro accelerometer is as follows:

in formula 8, t is time;

(4.3) whenAnd a is_xWhen not equal to 0, the output value of the gyro accelerometer is as follows:

in the formula (9), the first and second groups,

t is time;

(4.4) whenAnd the output value of the gyro accelerometer is as follows:

in the formula (11), the first and second groups,

t is time.

In a second aspect, the application of the method for measuring the output of the gyro accelerometer caused by the constant acceleration in the aspect of calibrating the error of the gyro accelerometer can be used on airplanes, ships, motor vehicles, missiles and the like.

The method for measuring the output of the gyro accelerometer caused by the constant acceleration has the following beneficial effects:

the invention comprehensively considers the influence of the acceleration of a constant input shaft and the lateral acceleration of the gyro accelerometer on the output, and provides a method for accurately calculating the theoretical calculation value of the gyro accelerometer by using the accelerations of three orthogonal directions of a base and the non-vertical angle beta of an outer frame shaft and a rotor shaft as known quantities. Compared with the existing linear output calculation method only considering the action of the input acceleration, the gyro accelerometer measuring method also considers the error term introduced when the transverse acceleration acts, and is more accurate, more comprehensive and wider in applicability.

Drawings

FIG. 1 is a schematic diagram of a gyroscopic accelerometer;

FIG. 2 is a flow chart of a gyro accelerometer output calculation of the present invention;

FIG. 3 shows a in example 1_x＝0、Outputting a calculated value by the time-dependent accelerometer;

FIG. 4 shows a in example 1_x＝5×tanβ、Time gyro accelerationOutputting the calculated value by the meter;

FIG. 5 shows a in example 1_x＝0.01、Outputting a calculated value by the time-dependent accelerometer;

FIG. 6 shows a in example 1_x＝1、The time-dependent accelerometer outputs a calculated value.

Detailed Description

The features and advantages of the present invention will become more apparent and appreciated from the following detailed description of the invention.

According to a first aspect of the present invention, there is provided a method of determining the output of a gyroscopic accelerometer due to a constant acceleration, from an input acceleration a_x、Y₀Axis and Z₀Constant transverse acceleration of the shaftAnd the size of the non-vertical angle beta, and calculating the real output of the gyro accelerometer by adopting different output models; as shown in fig. 2, the method specifically includes the following steps:

step (1), measuring a coordinate system OX of the gyro accelerometer fixedly connected with the base₀Y₀Z₀Constant input acceleration a_xAnd constant lateral accelerationWherein, a_xAnd OX₀Are in the same direction and are in the same direction,and OY₀Are in the same direction and are in the same direction,and OZ₀Are consistent in direction;

measuring a non-vertical angle beta of an outer frame shaft and a rotor shaft of the gyro accelerometer;

step (3) according to Y in step (1)₀Axis and Z₀Constant transverse acceleration of the shaftTo determine the resultant accelerationAnd OY₀The included angle gamma of the shaft satisfies:

at this time, at Y₀Axis and Z₀Constant transverse acceleration of the shaftThe differential equation of the gyro accelerometer in action is as follows:

wherein m is the eccentric mass of the rotor, l is the eccentric distance of the rotor, H is the angular momentum of the rotor of the instrument, alpha is the rotation angle of the outer frame relative to the base of the instrument (namely the shell of the pendulum type integral gyro accelerometer), which is called the rotation angle of the outer frame for short,the angular velocity of rotation of the outer frame;

step (4), setting the initial value of the outer frame angle alpha as alpha₀，α₀If the accuracy is known, the output of the gyro accelerometer is calculated according to the following four conditionsI.e. the angular velocity of the outer frame relative to the meter base (pendulum integrating gyroscopic accelerometer housing).

(4.1) when a_xWhen the value is equal to 0, the output value of the gyro accelerometer is as follows:

in formula 7, t is time.

(4.2) whenAnd the output value of the gyro accelerometer is as follows:

in formula 8, t is time.

(4.3) whenAnd a is_xWhen not equal to 0, the output value of the gyro accelerometer is as follows:

in the formula (9), the first and second groups,

t is time.

(4.4) whenAnd the output value of the gyro accelerometer is as follows:

in the formula (11), the first and second groups,

t is time.

In the invention, in the step (1), the acceleration a is input to the gyro accelerometer at a constant value_xAnd Y₀Axis and Z₀Constant transverse acceleration of the shaftThe measurement is obtained according to the measurement of 3 quartz accelerometers which are orthogonally arranged and are arranged on the inertial platform body.

In the invention, in the step (1), the acceleration a is input to the gyro accelerometer at a constant value_xAnd Y₀Axis and Z₀Constant transverse acceleration of the shaftThe acceleration with the amplitude less than or equal to 1g can be excited in the fixed orientation of the gravity field.

In the invention, in the step (1), the acceleration a is input to the gyro accelerometer at a constant value_xAnd Y₀Axis and Z₀Constant transverse acceleration of the shaftAcceleration of greater than 1g in magnitude can be excited at the centrifuge.

In the invention, in the step (1), a gyro rotor of the gyro accelerometer can be realized by dynamic pressure air flotation, liquid floating support and the like, and a bias pendulum structure of the gyro accelerometer can be realized by an eccentric pendulum structure, a shifting pendulum structure and the like.

In the invention, in the step (2), the non-perpendicular angle beta of the outer frame shaft and the rotor shaft of the gyro accelerometer is measured by the optical sighting mechanism of the static base.

According to a second aspect of the present invention, there is provided a use of a method for determining gyro-accelerometer output caused by constant acceleration in the calibration of gyro-accelerometer errors, the gyro-accelerometer being used in airplanes, ships, motor vehicles, missiles, etc.

Examples

Example 1

Is provided withβ＝1000″，α₀Pi/4, when a_x＝0、If the original calculation formula of the gyro accelerometer is usedThe calculation is performed and the output should be 0, as in the black bold line in fig. 3. And the following formula is calculated by adopting the calculation method of the invention,

the calculation results are shown by the black thin lines in FIG. 3, where the ordinate "darfa" representsThe unit is in °/s, the abscissa is time, the unit is s.

Example 2

Is provided withβ＝1000″，α₀Pi/4, when a_x＝5×tanβ、If the original calculation formula of the gyro accelerometer is usedThe calculation is performed and the output should be constant, as shown by the black bold line in fig. 4. And the following formula is calculated by adopting the calculation method of the invention,

the calculation results are shown by the black thin lines in FIG. 4, where the ordinate "darfa" representsThe unit is in °/s, the abscissa is time, the unit is s.

Example 3

Is provided withβ＝1000″，α₀Pi/4, when a_x＝0.01、If the original calculation formula of the gyro accelerometer is usedThe calculation is performed and the output should be constant, as shown by the black bold line in fig. 5. And the following formula is calculated by adopting the calculation method of the invention,

the calculation results are shown by the black thin lines in FIG. 5, where the ordinate "darfa" representsThe unit is in °/s, the abscissa is time, the unit is s.

Example 4

Is provided withβ＝1000″，α₀Pi/4, when a_x＝1、If the original calculation formula of the gyro accelerometer is usedThe calculation is performed and the output should be constant, as shown by the black bold line in fig. 6. And the following formula is calculated by adopting the calculation method of the invention,

the calculation results are shown by black thin lines in FIG. 6, where the ordinate "darfa" representsThe unit is in °/s, the abscissa is time, the unit is s.

The invention has been described in detail with reference to specific embodiments and illustrative examples, but the description is not intended to be construed in a limiting sense. Those skilled in the art will appreciate that various equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its embodiments without departing from the spirit and scope of the present invention, which fall within the scope of the present invention. The scope of the invention is defined by the appended claims.

Those skilled in the art will appreciate that those matters not described in detail in the present specification are well known in the art.