CN102052922A - Disturbing gravity compensation method for impacts of actual gravity field on inertial navigation system - Google Patents

Abstract

The invention discloses a method for compensating for the disturbance gravity of the inertial navigation system affected by the actual gravity field, which includes collecting the eastward and northward accelerations of the inertial navigation; separating the disturbance gravity to obtain the eastward and northward components of the disturbance gravity; Add the components to get the inertial navigation east acceleration after the disturbance gravity compensation; add the inertial navigation north acceleration and the disturbance gravity north component to get the inertial navigation north acceleration after the disturbance gravity compensation; for the inertial navigation east and north acceleration after the disturbance gravity compensation Integrate twice to obtain the eastward and northward displacements of the inertial navigation; add the eastward displacement of the inertial navigation to the northward displacement of the inertial navigation to obtain the new output position of the inertial navigation; use the normal gravity formula to obtain the normal gravity of the new output position of the inertial navigation; The actual gravity at the position of the inertial navigation system; the normal gravity vector is subtracted from the actual gravity vector to obtain the components of the disturbed gravity in the east and north directions. The invention improves the precision of the inertial navigation system.

Description

Compensation Method for Disturbed Gravity of Inertial Navigation System Influenced by Actual Gravity Field

technical field

The invention relates to the technical field of inertial navigation, in particular to a method for compensating the gravity disturbance of an inertial navigation system affected by an actual gravity field.

technical background

Due to the coverage of seawater, satellite navigation and astronomical navigation, which are successfully applied on the ground or in the air, cannot be used normally on underwater vehicles. , terrain matching navigation, etc.) have high hopes, but at present, this method still has a certain distance from engineering application, which makes the current inertial navigation system still an important guarantee for the safe navigation of underwater vehicles.

The accumulation of errors of inertial navigation systems over time has always been an important factor restricting the high precision of inertial navigation systems during long-distance underwater navigation. The root cause is the existence of gravity disturbance (the difference between the actual gravity and the normal gravity at the same point in space). For the inertial navigation system with medium and low precision, due to the relatively large errors of its sensors (gyro drift, accelerometer drift, etc.), generally using normal gravity for gravity compensation can meet the requirements. With the development of high-precision inertial navigation systems, the accuracy of inertial sensors has been greatly improved, and gravity disturbance has become the most important source of error in inertial navigation systems. The further improvement of inertial navigation system accuracy will mainly depend on the gravity Due to the undulations of the terrain, there is a large difference between the actual gravity on the ground and the gravity value calculated by the normal gravity formula. Therefore, the previous practice of using normal gravity in the inertial navigation mechanics equations is no longer satisfactory. Application requirements.

Contents of the invention

The purpose of the present invention is to provide a method for compensating the gravity disturbance of the inertial navigation system by the actual gravity field which can improve the accuracy of the inertial navigation system.

In order to achieve the above object, the present invention designs a kind of actual gravitational field influence inertial navigation system disturbance gravity compensation method, and it comprises the following steps:

Step S11: Collect the output of the eastward accelerometer of the inertial navigation system to obtain the eastward acceleration of the inertial navigation;

Step S51: Obtain the eastward component of the disturbance gravity through the separation of the disturbance gravity;

Step S21: Collect the output of the northward accelerometer of the inertial navigation system to obtain the northward acceleration of the inertial navigation system;

Step S52: Obtain the northward component of the disturbance gravity through the separation of the disturbance gravity;

Step S12: adding the eastward acceleration of the inertial navigation to the eastward component of the disturbance gravity to obtain the eastward acceleration S13 of the inertial navigation after compensation for the disturbance gravity;

Step S22: adding the northward acceleration of the inertial navigation and the northward component of the disturbance gravity to obtain the northward acceleration S23 of the inertial navigation after compensation for the disturbance gravity;

Step S14: Integrate the eastward acceleration of the inertial navigation system after the disturbance gravity compensation to obtain the eastward velocity of the inertial navigation system;

Step S24: Integrate the northward acceleration of the inertial navigation system after the disturbance gravity compensation to obtain the northward speed of the inertial navigation system;

Step S15: integrating the eastward speed of the inertial navigation system to obtain the eastward displacement S16 of the inertial navigation system;

Step S25: Integrate the northward speed of the inertial navigation system to obtain the northward displacement S26 of the inertial navigation system;

Step S3: adding the eastward displacement of the inertial navigation to the northward displacement of the inertial navigation to obtain a new output position S31 of the inertial navigation;

Step S32: using the normal gravity formula to obtain the normal gravity S33 at the new output position of the inertial navigation;

Step S41: Measure the actual gravity S42 at the position of the inertial navigation with the gravity sensor;

Step S5: Subtract the normal gravity vector from the actual gravity vector to obtain the disturbed gravity, and respectively obtain the eastward component of the disturbed gravity in step S51 and the northward component of the disturbed gravity in step S52.

Preferably, it also includes step S6: collecting the inertial navigation position data at the new output position S31 of the inertial navigation, adding the inertial navigation eastward displacement S16 and the inertial navigation northward displacement S26 to the inertial navigation position data, to obtain further The inertial navigation new output position S31.

The invention has the advantages that more accurate positioning results can be obtained by combining the actual gravity information in the calculation of the inertial navigation position, and the precision of the inertial navigation system is improved.

Description of drawings

Fig. 1 is the schematic diagram of the actual gravitational field influence inertial navigation system disturbance gravity compensation method;

Fig. 2 is a schematic diagram of a method for compensating the disturbance gravity of the inertial navigation system affected by the actual gravity field.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment the present invention will be described in further detail:

A kind of actual gravitational field influence inertial navigation system disturbance gravity compensation method as described in Fig. 1～2, it comprises the following steps:

Step S11: Collect the output of the eastward accelerometer of the inertial navigation system to obtain the eastward acceleration of the inertial navigation;

Step S51: Obtain the eastward component of the disturbance gravity through the separation of the disturbance gravity;

Step S21: Collect the output of the northward accelerometer of the inertial navigation system to obtain the northward acceleration of the inertial navigation system;

Step S52: Obtain the northward component of the disturbance gravity through the separation of the disturbance gravity;

Step S12: adding the eastward acceleration of the inertial navigation to the eastward component of the disturbance gravity to obtain the eastward acceleration S13 of the inertial navigation after compensation for the disturbance gravity;

Step S22: adding the northward acceleration of the inertial navigation and the northward component of the disturbance gravity to obtain the northward acceleration S23 of the inertial navigation after compensation for the disturbance gravity;

Step S14: Integrate the eastward acceleration of the inertial navigation system after the disturbance gravity compensation to obtain the eastward velocity of the inertial navigation system;

Step S24: Integrate the northward acceleration of the inertial navigation system after the disturbance gravity compensation to obtain the northward speed of the inertial navigation system;

Step S15: integrating the eastward speed of the inertial navigation system to obtain the eastward displacement S16 of the inertial navigation system;

Step S25: Integrate the northward speed of the inertial navigation system to obtain the northward displacement S26 of the inertial navigation system;

Step S3: adding the eastward displacement of the inertial navigation to the northward displacement of the inertial navigation to obtain a new output position S31 of the inertial navigation;

Step S32: using the normal gravity formula to obtain the normal gravity S33 at the new output position of the inertial navigation;

The normal gravity formula of the present invention is derived by the constant recommended by the 17th IUGG General Assembly in 1979, and its expression form is:

γ ₀ =978032.7(1+0.005302sin ² B-0.0000058sin ² 2B)×10 ^-5 ms ^-2 In the formula, B is the latitude, m is the meter, and s is the second.

Step S41: Measure the actual gravity S42 at the position of the inertial navigation with the gravity sensor;

Step S5: Subtract the normal gravity vector from the actual gravity vector to obtain the disturbed gravity, and respectively obtain the eastward component of the disturbed gravity in step S51 and the northward component of the disturbed gravity in step S52.

In the above technical solution, it also includes step S6: collecting the inertial navigation position data at the new output position S31 of the inertial navigation, adding the inertial navigation eastward displacement S16 and the inertial navigation northward displacement S26 to the inertial navigation position data, A new output position S31 of further inertial navigation is obtained.

In the above technical solution, the new output position of the inertial navigation in step S31 is the precise position of the inertial navigation system after the disturbance gravity compensation.

The principle of the present invention is as shown in Figure 1, the gravity of the current position is measured by the gravity sensor and then the disturbance gravity of the current position is obtained; the normal gravity of the current position is calculated by the normal gravity calculation formula; the disturbance gravity, normal gravity and inertial navigation are obtained according to the current position The acceleration output by the accelerometer determines the real acceleration of the current position; the real acceleration of the current position is integrated twice to obtain a new positioning position. The above-mentioned whole operation steps are completed in the PC1044 embedded computer.

The above description is a preferred embodiment of the present invention, and it should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications are also considered Be the protection scope of the present invention.

The content not described in detail in this specification belongs to the prior art known to those skilled in the art.

Claims (2)

1. an A/W field influences the compensation method of inertial navigation system disturbing gravity, and it comprises the steps:

Step S11: gather the output quantity of the east orientation accelerometer of inertial navigation system, obtain inertial navigation east orientation acceleration;

Step S51: obtain the disturbing gravity east component by the disturbing gravity separation;

Step S21: gather the output quantity of the north orientation accelerometer of inertial navigation system, obtain inertial navigation north orientation acceleration;

Step S52: obtain the disturbing gravity north component by the disturbing gravity separation;

Step S12: described inertial navigation east orientation acceleration and the addition of disturbing gravity east component are obtained the inertial navigation east orientation acceleration S13 that the process disturbing gravity compensates;

Step S22: described inertial navigation north orientation acceleration and the addition of disturbing gravity north component are obtained the inertial navigation north orientation acceleration S23 that the process disturbing gravity compensates;

Step S14:, obtain inertial navigation east orientation speed to described inertial navigation east orientation integrated acceleration through the disturbing gravity compensation;

Step S24:, obtain inertial navigation north orientation speed to described inertial navigation north orientation integrated acceleration through the disturbing gravity compensation;

Step S15:, obtain inertial navigation east orientation displacement S16 to described inertial navigation east orientation rate integrating;

Step S25:, obtain inertial navigation north orientation displacement S26 to described inertial navigation north orientation rate integrating;

Step S3: the displacement of described inertial navigation east orientation is added the displacement of inertial navigation north orientation, obtain the new outgoing position S31 of inertial navigation;

Step S32: adopt normal gravity formula, obtain normal gravity S33 at the new outgoing position place of described inertial navigation;

Step S41: the A/W S42 that measures place, inertial navigation present position with gravity sensor;

Step S5: deduct the normal gravity vector with described A/W vector, obtain disturbing gravity, and obtain respectively disturbing gravity among the described step S51 in the component of east orientation and described step S52 disturbing gravity at the component of north orientation.

2. A/W according to claim 1 field influences the compensation method of inertial navigation system disturbing gravity, it is characterized in that: it also comprises step S6: the inertial navigation position data of gathering the new outgoing position S31 place of described inertial navigation, described inertial navigation position data is added inertial navigation east orientation displacement S16 and inertial navigation north orientation displacement S26, obtain the new outgoing position S31 of further inertial navigation.

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