阅读说明：本技术 一种陀螺加速度计的输出补偿方法 (Output compensation method of gyro accelerometer ) 是由 魏宗康 于 2020-12-11 设计创作，主要内容包括：本发明提供了一种陀螺加速度计的输出补偿方法,根据时变输入加速度a-x、横向加速度以及不垂直角度β的大小,采用误差补偿的方法,计算出陀螺加速度计的真实加速度输出值；计算的陀螺加速度计输出加速度值不仅包括输入轴加速度的相关项,还包括由于横向加速度作用时引入的误差项,相比现有的无补偿时的加速度输出计算方法,本发明的计算方法更准确、精度高、线性度好。(The invention provides an output compensation method of a gyro accelerometer, which is based on time-varying input acceleration a x Lateral acceleration Calculating the real acceleration output value of the gyro accelerometer by adopting an error compensation method according to the size of the non-vertical angle beta; the calculated output acceleration value of the gyro accelerometer not only comprises a relevant item of the acceleration of the input shaft, but also comprises an error item introduced under the action of the transverse acceleration.)

1. An output compensation method of a gyro accelerometer is characterized by comprising the following steps:

step (1), measuring a coordinate system OX of the gyro accelerometer fixedly connected with the base₀Y₀Z₀Input acceleration a of_xAnd lateral accelerationWherein, a_xAnd OX₀The directions of the axes are consistent with each other,and OY₀The directions of the axes are consistent with each other,and OZ₀The axial directions are consistent;andis a constant value;

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 Z₀Transverse acceleration of the shaftTo determine the resultant accelerationAnd OY₀The included angle gamma of the shaft satisfies:

at this time, at Y₀Axis and Z₀Transverse 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) whenThen, the angle is calculated according to the following two formulas

Step (5), setting the initial value of the outer frame angle alpha of the gyro accelerometer as alpha₀For the angular velocity of the outer frame output by the gyro accelerometerCompensating to output OX₀Acceleration on axis a_x’：

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

t is time.

2. The output compensation method of a gyro accelerometer according to claim 1, wherein in step (1), the input acceleration a of the gyro accelerometer is_xAnd Y₀Axis and Z₀Transverse 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 output compensation of a gyro accelerometer according to claim 1, wherein in step (1), the gyro accelerometer is mounted in an inclined manner with respect to the thrust of the platform missile engine so that the input acceleration is applied

4. The output compensation method of a gyro accelerometer according to claim 1, wherein in step (1), the input acceleration a of the gyro accelerometer is_xAnd Y₀Axis and Z₀Transverse acceleration of the shaftAcceleration with the amplitude less than or equal to 1g can be excited in the fixed orientation of the gravity field in a mode of inclining relative to the vector direction of the gravity acceleration.

5. The output compensation method of a gyro accelerometer according to claim 1, wherein in step (1), the input acceleration a of the gyro accelerometer is_xAnd Y₀Axis and Z₀Transverse acceleration of the shaftAccelerations with amplitudes greater than 1g can be excited at large overloads including centrifuge, rocket sledge, live-action flight.

6. The output compensation method of the gyro accelerometer according to claim 1, wherein in step (1), the gyro rotor of the gyro accelerometer can be implemented by dynamic pressure air flotation, liquid floating support, etc., and the yaw structure of the gyro accelerometer can be implemented by an eccentric pendulum structure, a tilt-shift pendulum structure, etc.

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

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 an output compensation method for a gyro accelerometer.

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 below. 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 OrUnder zero initial conditions, there is an ideal output value:

in order to ensure that H is vertical to the axis OX of the outer frame, the gyro accelerometer is additionally provided with a servo loop when suffering 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 are perpendicular to each other when there is a deviation in the mechanical zero position of the angle sensor, and for this reason, this non-perpendicular angle is collectively 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 Z₀Lateral 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. In engineering applications, the angular velocity is output according to a gyro accelerometerThe method for calculating the acceleration is a simplified equation:

however, the simplified method can cause measurement errors of the gyro accelerometer, thereby influencing the use precision of the instrument and directly causing the point-of-fall errors of the navigation and guidance of the missile.

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 output compensation method of the gyro accelerometer so as to improve the visual acceleration precision measurement capability of the gyro accelerometer.

Disclosure of Invention

The technical problem of the invention is solved: the method is used for calculating the accurate acceleration output value of the gyro accelerometer and has high accuracy.

The technical scheme provided by the invention is as follows:

an output compensation method of a gyro accelerometer comprises the following steps:

step (1), measuring a coordinate system OX of the gyro accelerometer fixedly connected with the base₀Y₀Z₀Input acceleration a of_xAnd lateral accelerationWherein, a_xAnd OX₀The directions of the axes are consistent with each other,and OY₀The directions of the axes are consistent with each other,and OZ₀The axial directions are consistent;andis a constant value;

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 Z₀Transverse acceleration of the shaftTo determine the resultant accelerationAnd OY₀The included angle gamma of the shaft satisfies:

at this time, at Y₀Axis and Z₀Transverse 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) whenThen, the angle is calculated according to the following two formulas

Step (5), setting the initial value of the outer frame angle alpha of the gyro accelerometer as alpha₀For the angular velocity of the outer frame output by the gyro accelerometerCompensating to output OX₀Acceleration on axis a_x’：

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

t is time.

The output compensation method of the gyro accelerometer provided by the invention has the following beneficial effects:

the invention comprehensively considers the influence of the time-varying input shaft acceleration and the transverse acceleration of the gyro accelerometer on the output, and provides a method for accurately calculating the theoretical acceleration value of the gyro accelerometer by using the accelerations of the base in three orthogonal directions and the non-vertical angle beta between the outer frame shaft and the rotor shaft as known quantities. Compared with the existing linear output calculation method only considering the action of the input acceleration, the gyro accelerometer has more accurate and comprehensive compensated acceleration and wider 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 base axis X of a gyroscopic accelerometer of example 1₀、Y₀The value of the overload experienced;

FIG. 4 is a raw acceleration calculation for a gyroscopic accelerometer of example 1;

FIG. 5 is an acceleration error caused by the gyro accelerometer in example 1 using the original calculation method;

FIG. 6 is a calculated value of an accelerometer of a gyroscopic accelerometer of example 1 compensated using the present invention;

fig. 7 shows the calculation error of the compensated acceleration of the gyro accelerometer in example 1.

Detailed Description

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

The invention provides an output compensation method of a gyro accelerometer, as shown in figure 2, according to input acceleration a_x、Y₀Axis and Z₀Transverse 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, wherein the method specifically comprises the following steps:

step (1), measuring a coordinate system OX of the gyro accelerometer fixedly connected with the base₀Y₀Z₀Input acceleration a of_xAnd lateral accelerationWherein, a_xAnd OX₀The directions of the axes are consistent with each other,and OY₀The directions of the axes are consistent with each other,and OZ₀The axial directions are consistent;andis a constant value;

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 Z₀Transverse acceleration of the shaftTo determine the resultant accelerationAnd OY₀The included angle gamma of the shaft satisfies:

at this time, at Y₀Axis and Z₀Transverse 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) whenThen, the angle is calculated according to the following two formulas

Step (5), setting the initial value of the outer frame angle alpha of the gyro accelerometer as alpha₀For the angular velocity of the outer frame output by the gyro accelerometerCompensating to output OX₀Acceleration on axis a_x' the method is as follows:

in the formula (I), the compound is shown in the specification,

t is time.

In the invention, in the step (1), the input acceleration a of the gyro accelerometer_xAnd Y₀Axis and Z₀Transverse 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 gyro accelerometer can adopt an inclined installation mode relative to the thrust of the platform missile engine to ensure the input acceleration

In the invention, in the step (1), the input acceleration a of the gyro accelerometer_xAnd Y₀Axis and Z₀Transverse acceleration of the shaftAcceleration with the amplitude less than or equal to 1g can be excited in the fixed orientation of the gravity field in a mode of inclining relative to the vector direction of the gravity acceleration.

In the invention, in the step (1), the input acceleration a of the gyro accelerometer_xAnd Y₀Axis and Z₀Transverse acceleration of the shaftAccelerations with amplitudes greater than 1g can be excited at large overloads including centrifuge, rocket sledge, live-action flight.

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 other modes, a deflexion pendulum structure of the gyro accelerometer can be realized by an eccentric pendulum structure, a shifting shaft type pendulum structure and other modes, and a carrier measured by the gyro accelerometer can be an airplane, a ship, a motor vehicle, a missile 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.

Examples

Example 1

Is provided withβ＝1000″，α₀＝π/4，When the theoretical acceleration a_x、In case of time-varying overload, as shown in FIG. 3, the two satisfy the relationIf according to the original calculation formula of the gyro accelerometerCalculation was performed with the output acceleration as shown in fig. 4; compared with fig. 3, the difference value between the theoretical acceleration value and the error value is shown in fig. 5, and it can be seen that the error is an alternating variable, the amplitude of the error becomes larger with the increase of the acceleration, and the maximum acceleration error can reach 0.05 g. Calculated by the compensation method of the inventionThe result is shown in FIG. 6, where the ordinate represents the acceleration a output from the gyro accelerometer_x', units are g; the difference between the two is shown in FIG. 7, and the error of the maximum acceleration is 0.0015 g. It can be seen that the output result of the gyro accelerometer compensated by the invention is more accurate.

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.