阅读说明：本技术 一种用于惯导的自适应加速度计温度补偿方法 (Adaptive accelerometer temperature compensation method for inertial navigation ) 是由 林建华 张铭涛 吴成智 肖波 谷丛 邵添羿 吴枫 邵俊琦 于 2019-10-29 设计创作，主要内容包括：本发明公开了一种用于惯导的自适应加速度计温度补偿方法,该方法包含：S1、测试多组全温度范围内的惯导输出的加速度计数据；S2、对步骤S1得到的多组加速度计数据进行计算分析,得到多组加速度计的输出特性；S3、根据步骤S2中加速度计的输出特性,建立多组数学模型；S4、根据惯导开机的工作状态参数,从多组数学模型中选取最佳数学模型作为当前工作状态的温度补偿模型进行温度补偿。其优点是：该方法通过多次采集加速度计在全温度范围内的输出数据,运用大数据分析出该加速度计随温度变化的特性,得到多种分段直线或曲线拟合的数学模型,利用不同的数学模型匹配不同工作条件下的数据输出特性,提高了加速度计的测量精度以及温度补偿方法的有效性。(The invention discloses a temperature compensation method of a self-adaptive accelerometer for inertial navigation, which comprises the following steps: s1, testing multiple groups of accelerometer data output by inertial navigation within a full temperature range; s2, carrying out calculation analysis on the multiple groups of accelerometer data obtained in the step S1 to obtain the output characteristics of the multiple groups of accelerometers; s3, establishing a plurality of groups of mathematical models according to the output characteristics of the accelerometer in the step S2; and S4, selecting the optimal mathematical model from the multiple sets of mathematical models as the temperature compensation model of the current working state for temperature compensation according to the working state parameters of the inertial navigation starting machine. The advantages are that: according to the method, output data of the accelerometer in the full temperature range are collected for multiple times, characteristics of the accelerometer changing along with temperature are analyzed by using big data, a plurality of segmented straight line or curve fitting mathematical models are obtained, different mathematical models are used for matching data output characteristics under different working conditions, and the measurement accuracy of the accelerometer and the effectiveness of a temperature compensation method are improved.)

1. A method for temperature compensation of an adaptive accelerometer used for inertial navigation, the method comprising:

s1, testing multiple groups of accelerometer data output by inertial navigation within a full temperature range;

s2, carrying out calculation analysis on the multiple groups of accelerometer data obtained in the step S1 to obtain the output characteristics of the multiple groups of accelerometers;

s3, establishing a plurality of groups of mathematical models according to the output characteristics of the accelerometer in the step S2;

and S4, selecting the optimal mathematical model from the multiple sets of mathematical models as the temperature compensation model of the current working state for temperature compensation according to the working state parameters of the inertial navigation starting machine.

2. The adaptive accelerometer temperature compensation method for inertial navigation according to claim 1, wherein the step S1 specifically comprises:

and (3) placing three axes of inertial navigation in a temperature test box with an independent foundation in the horizontal direction respectively, and measuring and recording accelerometer data output by inertial navigation in a full temperature range for multiple times.

3. The adaptive accelerometer temperature compensation method for inertial navigation of claim 1 or 2,

the inertial navigation output accelerometer data over the full temperature range includes: the method comprises the following steps of outputting first-class accelerometer data by inertial navigation under the condition of automatic temperature rise from low temperature to high temperature and outputting second-class accelerometer data by inertial navigation under the condition of constant temperature at multiple temperature points.

4. The adaptive accelerometer temperature compensation method for inertial navigation according to claim 3, wherein the step S2 specifically comprises:

the output characteristic of the accelerometer comprises a characteristic curve and a characteristic straight line;

generating a data variation curve by a plurality of groups of first-class accelerometer data according to the change of temperature from low to high, and selecting a characteristic curve from each data variation curve;

and respectively calculating the average value of the second type accelerometer data of the multiple groups of constant temperature measuring points, then respectively fitting the second type accelerometer data of each group by adopting a segmented least square method, and selecting a characteristic straight line from each fitting result.

5. The adaptive accelerometer temperature compensation method for inertial navigation of claim 4,

the characteristic curve is a curve with the data deviation value of the first type accelerometer being larger than 1mg at the same temperature point;

the characteristic straight line is a segmented straight line with the data deviation value of the second type accelerometer being larger than 1mg at the same temperature point.

6. The adaptive accelerometer temperature compensation method for inertial navigation according to claim 4, wherein the step S3 specifically comprises:

and establishing a mathematical model fitting the piecewise straight line through the characteristic curve, comparing the piecewise straight line fitting in the mathematical model with the characteristic straight line, and selecting a plurality of final mathematical models.

7. The adaptive accelerometer temperature compensation method for inertial navigation of claim 6,

and the final multiple groups of mathematical models are models with the fitting error of the accelerometer data being less than 0.2 mg.

8. The adaptive accelerometer temperature compensation method for inertial navigation of claim 1,

the operating state parameters in said step S4 include the actual accelerometer data and the current temperature point.

9. The adaptive accelerometer temperature compensation method for inertial navigation according to claim 1 or 8, wherein the step S4 specifically comprises:

and automatically smoothing actual accelerometer data output within n seconds after the inertial navigation start-up, calculating accelerometer data output by each mathematical model through the current temperature point, comparing the accelerometer data output by each mathematical model with the actual accelerometer data, and selecting the mathematical model corresponding to the accelerometer data with the minimum deviation as the temperature compensation model in the current working state for temperature compensation.

Technical Field

The invention relates to the field of inertial navigation, in particular to a temperature compensation method for a self-adaptive accelerometer for inertial navigation.

Background

The inertial navigation system can output position, attitude and speed information under the condition of giving an initial position, is widely applied to the fields of aviation, aerospace, navigation and the like, and becomes important navigation equipment of a carrier rocket, a strategic weapon and a submarine. In addition, inertial navigation systems are widely used in civil applications, such as coal mining, oil drilling, and pipe laying. Accordingly, inertial navigation technology is becoming increasingly important in military activities and everyday life.

The inertial navigation is a main component in an inertial navigation system, and has the main functions of measuring the angular velocity and the apparent acceleration of three axes of a carrier in real time and providing the following information after error compensation: three-axis angular increment, angular velocity instant quantity, three-axis apparent velocity increment, apparent acceleration instant quantity and temperature information.

The inertial navigation mainly comprises a gyroscope and an accelerometer, wherein the accelerometer is sensitive to the ambient temperature. Under different temperature conditions, the deviation of the acceleration information output by the inertial navigation is large, so that the method has important significance for the research of the temperature characteristic and the compensation method of the accelerometer in the inertial navigation. The currently used temperature compensation methods mainly include polynomial fitting methods and piecewise linear fitting methods. However, the two methods require an accurate mathematical model between the output data of the accelerometer and the temperature change value, and the accelerometer has certain uncertainty along with the change of the temperature in the engineering application process, and often generates certain deviation in the two adjacent test processes, namely the zero offset repeatability of the accelerometer is poor, so that the accelerometer is difficult to improve the measurement accuracy by using a single curve fitting or piecewise straight line fitting temperature compensation method.

Disclosure of Invention

The invention aims to provide a temperature compensation method of a self-adaptive accelerometer for inertial navigation, which is characterized in that output data of the accelerometer in a full temperature range are collected for multiple times, a large amount of data are tested, the characteristic of the accelerometer changing along with the temperature is analyzed through big data, a plurality of segmented straight line or curve fitting mathematical models are obtained, different mathematical models are used for matching data output characteristics under different working conditions, the measurement precision of the accelerometer is improved, and the effectiveness of the temperature compensation method is also improved.

In order to achieve the purpose, the invention is realized by the following technical scheme:

a method for adaptive accelerometer temperature compensation for inertial navigation, the method comprising:

s1, testing multiple groups of accelerometer data output by inertial navigation within a full temperature range;

s2, carrying out calculation analysis on the multiple groups of accelerometer data obtained in the step S1 to obtain the output characteristics of the multiple groups of accelerometers;

s3, establishing a plurality of groups of mathematical models according to the output characteristics of the accelerometer in the step S2;

and S4, selecting the optimal mathematical model from the multiple sets of mathematical models as the temperature compensation model of the current working state for temperature compensation according to the working state parameters of the inertial navigation starting machine.

Preferably, the step S1 is specifically:

and (3) placing three axes of inertial navigation in a temperature test box with an independent foundation in the horizontal direction respectively, and measuring and recording accelerometer data output by inertial navigation in a full temperature range for multiple times.

Preferably, the inertial navigation output accelerometer data over the full temperature range comprises: the method comprises the following steps of outputting first-class accelerometer data by inertial navigation under the condition of automatic temperature rise from low temperature to high temperature and outputting second-class accelerometer data by inertial navigation under the condition of constant temperature at multiple temperature points.

Preferably, the step S2 is specifically:

the output characteristic of the accelerometer comprises a characteristic curve and a characteristic straight line;

generating a data variation curve by a plurality of groups of first-class accelerometer data according to the change of temperature from low to high, and selecting a characteristic curve from each data variation curve;

and respectively calculating the average value of the second type accelerometer data of the multiple groups of constant temperature measuring points, then respectively fitting the second type accelerometer data of each group by adopting a segmented least square method, and selecting a characteristic straight line from each fitting result.

Preferably, the characteristic curve is a curve that the data deviation value of the first type of accelerometer is greater than 1mg at the same temperature point;

the characteristic straight line is a segmented straight line with the data deviation value of the second type accelerometer being larger than 1mg at the same temperature point.

Preferably, the step S3 is specifically:

and establishing a mathematical model fitting the piecewise straight line through the characteristic curve, comparing the piecewise straight line fitting in the mathematical model with the characteristic straight line, and selecting a plurality of final mathematical models.

Preferably, the final sets of mathematical models are models having an accelerometer data fitting error of less than 0.2 mg.

Preferably, the operating state parameters in step S4 include actual accelerometer data and current temperature point.

Preferably, the step S4 is specifically:

and automatically smoothing actual accelerometer data output within n seconds after the inertial navigation start-up, calculating accelerometer data output by each mathematical model through the current temperature point, comparing the accelerometer data output by each mathematical model with the actual accelerometer data, and selecting the mathematical model corresponding to the accelerometer data with the minimum deviation as the temperature compensation model in the current working state for temperature compensation.

Compared with the prior art, the invention has the following advantages:

(1) according to the temperature compensation method for the adaptive accelerometer for inertial navigation, disclosed by the invention, commonalities are searched from differences of output characteristics of the accelerometer through big data analysis, and different temperature compensation models are established, so that the defect that a single temperature compensation model is adopted in the existing temperature compensation technology is overcome, and the measurement precision of the accelerometer is improved;

(2) according to the temperature compensation method for the self-adaptive accelerometer for inertial navigation, disclosed by the invention, the temperature compensation model is automatically matched according to the first n seconds of data output by the accelerometer under different environmental conditions, so that the effectiveness of the temperature compensation method and the temperature compensation precision of the accelerometer under a certain working environment are improved, and the measurement precision of inertial navigation on the acceleration of a carrier under all-weather conditions is further improved;

(3) according to the temperature compensation method for the self-adaptive accelerometer for inertial navigation, disclosed by the invention, the first type of accelerometer data output by inertial navigation under the condition that the temperature is automatically raised from low temperature to high temperature and the second type of accelerometer data output by inertial navigation under the condition of constant temperature at multiple temperature points are acquired, so that the sample universality is improved, and the accuracy of the temperature compensation method is enhanced.

Drawings

FIG. 1 is a schematic flow chart of a method for compensating temperature of an adaptive accelerometer for inertial navigation according to the present invention.

Detailed Description

The present invention will now be further described by way of the following detailed description of a preferred embodiment thereof, taken in conjunction with the accompanying drawings.

Because the accelerometer has poor zero-bias repeatability in the working process, a single mathematical model cannot represent the working characteristics of the accelerometer under various environmental conditions. In order to reduce the influence of the output uncertainty of the accelerometer on the output of inertial navigation, the adaptive accelerometer temperature compensation method for inertial navigation collects output data of the accelerometer in the full temperature range for multiple times, tests a large amount of data, analyzes the characteristic of the accelerometer changing along with the temperature through big data, obtains various segmented linear or curve fitting mathematical models, and utilizes different mathematical models to match the output change characteristic of typical data under different working conditions.

Fig. 1 is a schematic flow chart of a method for temperature compensation of an adaptive accelerometer for inertial navigation according to the present invention, the method comprising:

and S1, testing multiple groups of accelerometer data output by inertial navigation in the full temperature range to obtain more comprehensive data of the accelerometer at each temperature point and under the condition of temperature change.

Wherein, the accelerometer data output by inertial navigation in the full temperature range comprises: the method comprises the following steps of outputting first-class accelerometer data by inertial navigation under the condition of automatic temperature rise from low temperature to high temperature and outputting second-class accelerometer data by inertial navigation under the condition of constant temperature at multiple temperature points.

The step S1 specifically includes: and (3) placing three axes of inertial navigation in a temperature test box with an independent foundation in the horizontal direction respectively, and measuring and recording accelerometer data output by inertial navigation in a full temperature range for multiple times.

In this embodiment, accelerometer data at-40 ℃ to 60 ℃ needs to be tested, and the specific method is as follows:

(1) firstly, reducing the temperature of a temperature test box to-40 ℃ and preserving heat for 2 hours, then gradually increasing the temperature to 60 ℃ at the speed of 2 ℃/min and preserving heat for 2 hours, and recording the output of accelerometer data in the whole process, namely acquiring the first type of accelerometer data;

(2) after the test under the automatic temperature changing condition is completed, selecting a typical temperature point within a target temperature range: -40 ℃, -35 ℃, -30 ℃, -25 ℃, -20 ℃, -15 ℃, -10 ℃, -5 ℃, 0 ℃, 5 ℃, 10 ℃, 15 ℃, 20 ℃, 25 ℃, 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃, 55 ℃ and 60 ℃ (the number of selected points can be increased according to actual needs), carrying out constant temperature test, and recording the accelerometer data of inertial navigation at each constant temperature point, namely collecting the second type of accelerometer data;

(3) and (3) repeating the work in the steps (1) and (2) for 5-8 times, and storing all data.

And S2, calculating and analyzing the multiple groups of accelerometer data obtained in the step S1 to obtain the output characteristics of the accelerometer. Wherein the output characteristic of the accelerometer comprises a characteristic curve and a characteristic straight line.

The step S2 specifically includes: all acceleration data stored in the full temperature range are adopted, 5-8 groups of first-class accelerometer data are generated into a data variation curve according to the change of temperature from low to high, the data variation curves of all groups are compared, and a curve with the deviation of the first-class accelerometer data larger than 1mg at the same temperature point is found out from all the groups to serve as a characteristic curve and serve as a basis for building a mathematical model.

Respectively calculating the average value of the second type accelerometer data of 5-8 groups of constant temperature measuring points, respectively fitting each group of second type accelerometer data by adopting a segmented least square method, comparing the fitted segmented straight lines, taking the segmented straight lines with the deviation value of the second type accelerometer data larger than 1mg at the same temperature point as characteristic straight lines, and selecting the characteristic straight lines for establishing a mathematical model.

And S3, establishing a plurality of groups of mathematical models for the temperature compensation algorithm according to the output characteristics of the accelerometer.

The step S3 specifically includes: and establishing a mathematical model of a piecewise fitting straight line through the characteristic curve, comparing the piecewise straight line fitted in the mathematical model with the characteristic straight line, and selecting a model with an accelerometer data fitting error smaller than 0.2mg as a final plurality of groups of mathematical models for the more similar piecewise straight lines after fitting.

And S4, selecting the optimal mathematical model from the multiple sets of mathematical models as the temperature compensation model of the current working state for temperature compensation according to the working state parameters of the inertial navigation starting machine. In this embodiment, the operating state parameter of the inertial navigation boot is an actual operating parameter output within 20 seconds of the inertial navigation boot.

The operating state parameters in said step S4 include the actual accelerometer data and the current temperature point.

The step S4 specifically includes: and automatically smoothing the actual accelerometer data output within 20 seconds after the inertial navigation is started by a CPU (central processing unit) in the inertial navigation, smoothing the actual accelerometer data for 1 second, calculating the accelerometer data output by each mathematical model through the current temperature point, comparing the accelerometer data output by each mathematical model with the actual accelerometer data, and selecting the mathematical model corresponding to the accelerometer data with the minimum deviation as a temperature compensation model of the current accelerometer working state for temperature compensation.

In summary, the adaptive accelerometer temperature compensation method for inertial navigation of the invention overcomes the defects of the existing accelerometer temperature compensation method, can find out typical common characteristics from big data after a large amount of data tests, and utilizes different mathematical models to match the output change characteristics of typical data under different working conditions. The inertial navigation automatically matches the temperature compensation model by judging the output value and the temperature value of the accelerometer which is started up under a certain environment temperature and works within n seconds, namely the temperature compensation model is matched firstly, and then temperature compensation is carried out according to the matched temperature compensation model, so that the effectiveness of the temperature compensation method is improved, the temperature compensation precision of the accelerometer under a certain working environment is improved, and the measurement precision of the inertial navigation on the acceleration of the carrier under all-weather conditions is further improved.

While the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention. Various modifications and alterations to this invention will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, the scope of the invention should be determined from the following claims.