Azimuth detection method and device

Abstract

The invention provides an orientation detection method and device, relates to the technical field of inertial measurement, and is used for determining an orientation by using a gyro north seeker. The method comprises the following steps: acquiring first azimuth information; determining a first direction, a second direction, a third direction and a fourth direction according to the first azimuth information; wherein the first direction is the direction corresponding to the east direction minus the preset degree, the second direction is the direction corresponding to the east direction plus the preset degree, the third direction is the direction corresponding to the west direction minus the preset degree, and the fourth direction is the direction corresponding to the west direction plus the preset degree; the preset degree is smaller than 90 degrees. And determining the earth rotation angular velocity measured under the condition that the gyroscope rotates to the first direction, the second direction, the third direction and the fourth direction respectively. According to the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity, second azimuth information is determined, and the second azimuth information is used for indicating the current azimuth.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of inertial measurement, and in particular to a direction detection method and device. BACKGROUND

[0002] At present, direction is important information in human production and life, and modern society has high requirements for direction detection technology in various fields. For example, the direction needs to be determined in the navigation process of vehicles, ships, unmanned aerial vehicles and other equipment, and the direction also needs to be determined in underground operations such as tunnels and mines.

[0003] In the prior art, on the one hand, the direction can be determined by measuring the earth's magnetic field by using a magnetometer or a compass; this method has low north-seeking accuracy and is easily disturbed by other magnetic fields, and can only be used for rough orientation. On the other hand, the direction can also be determined by using astronomical information; this method has the advantages of high accuracy, but the disadvantages are complex equipment, very time-consuming and unable to orient in a closed environment. On the other hand, the direction can be determined by using a global satellite navigation system; this method has fast response speed and relatively high accuracy, but it depends on satellites and cannot be used in satellite-shielded environments.

[0004] In addition, in the prior art, the direction can also be determined by using a gyro north finder. The gyro north finder can autonomously determine the true north direction of a carrier by measuring the earth's rotation angular velocity by using inertial devices. The current gyro north finder has the advantages of being not restricted by natural conditions, and being able to realize all-weather, all-direction, autonomous and fast direction measurement. However, the precision of the micro-electro-mechanical system (MEMS) gyro north finder currently used is low, and the high-precision fiber-optic gyro is expensive.

[0005] Therefore, how to optimize the gyro north-seeking scheme and improve the precision of the gyro north-seeking under the condition of limited hardware is a problem to be solved at present. SUMMARY

[0006] The present application provides a direction detection method and device for improving the direction detection precision and reducing the hardware cost.

[0007] In a first aspect, a direction detection method is provided, comprising: obtaining first direction information; the first direction information is used to indicate an east direction and a west direction; determining a first direction, a second direction, a third direction and a fourth direction according to the first direction information; the first direction is a direction corresponding to the east direction minus a preset angle, the second direction is a direction corresponding to the east direction plus the preset angle, the third direction is a direction corresponding to the west direction minus the preset angle, and the fourth direction is a direction corresponding to the west direction plus the preset angle; the preset angle is less than 90°; determining a first angular velocity, a second angular velocity, a third angular velocity and a fourth angular velocity; the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity are respectively measured angular velocities of the earth rotation when a gyroscope rotates to the first direction, the second direction, the third direction and the fourth direction; and determining second direction information according to the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity, the second direction information being used to indicate a current direction.

[0008] In the above direction detection method provided by the embodiments of the present application, after obtaining the first direction information with low precision, four directions (i.e., the first direction is a direction corresponding to the east direction minus a preset angle, the second direction is a direction corresponding to the east direction plus the preset angle, the third direction is a direction corresponding to the west direction minus the preset angle, and the fourth direction is a direction corresponding to the west direction plus the preset angle; the preset angle is less than 90°) that meet the conditions are determined according to the first direction information, then the angular velocities (i.e., the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity) of the earth rotation measured when the gyroscope rotates to the first direction, the second direction, the third direction and the fourth direction are determined, and then the second direction information used to indicate the current direction is determined according to the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity. In this way, more accurate direction information (i.e., the second direction information) can be obtained.

[0009] In an implementation manner, the first direction information is direction information obtained by using a gyroscope to find north.

[0010] In an implementation manner, the first direction information is direction information obtained by using the earth magnetic field.

[0011] In an implementation manner, the second direction information includes an angle of a to-be-detected direction; the first angular velocity, the second angular velocity, the third angular velocity, the fourth angular velocity and the direction information of the to-be-detected direction meet the following formula one:

[0012]

[0013] In the formula one, ω1 represents the first angular velocity, ω2 represents the second angular velocity, ω3 represents the third angular velocity, ω4 represents the fourth angular velocity, and θ represents the angle of the to-be-detected direction. θ1, θ2, θ3, θ4 represent the angle of the direction to be detected, θ1 represents the included angle between the first direction and the direction to be detected, θ2 represents the included angle between the second direction and the direction to be detected, θ3 represents the included angle between the third direction and the direction to be detected, and θ4 represents the included angle between the fourth direction and the direction to be detected, ω ie ω represents the angular velocity of the earth rotation, L represents the local latitude, and ε F ω represents the angular velocity of the earth rotation, L represents the local latitude, and ε

[0014] In an implementation, the second azimuth information includes an angle of the direction to be detected; and the second azimuth information is determined according to the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity, including: determining a vector X satisfying the following formula two according to the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity:

[0015] X = (B T B) -1 B T A formula two

[0016] wherein, ω1 represents the first angular velocity, ω2 represents the second angular velocity, ω3 represents the third angular velocity, ω4 represents the fourth angular velocity, θ1 represents the included angle between the first direction and the direction to be detected, θ2 represents the included angle between the second direction and the direction to be detected, θ3 represents the included angle between the third direction and the direction to be detected, and θ4 represents the included angle between the fourth direction and the direction to be detected. The angle of the direction to be detected is determined according to the vector X; wherein the angle of the direction to be detected satisfies the following formula three:

[0017]

[0018] wherein, X[2] represents the first item of the vector X, and X[1] represents the second item of the vector X.

[0019] In an implementation, the method is applied to a micro-electro-mechanical system (MEMS) gyro north seeker, or the method is applied to an optical fiber gyro north seeker.

[0020] In a second aspect, a direction detection device is provided, which comprises: an acquisition unit configured to acquire first direction information, the first direction information being used to indicate an east direction and a west direction; a processing unit configured to determine a first direction, a second direction, a third direction and a fourth direction according to the first direction information, wherein the first direction is a direction corresponding to the east direction minus a preset angle, the second direction is a direction corresponding to the east direction plus the preset angle, the third direction is a direction corresponding to the west direction minus the preset angle, and the fourth direction is a direction corresponding to the west direction plus the preset angle, and the preset angle is less than 90°; the processing unit is further configured to determine a first angular velocity, a second angular velocity, a third angular velocity and a fourth angular velocity, wherein the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity are respectively measured angular velocities of the earth rotation when a gyroscope rotates to the first direction, the second direction, the third direction and the fourth direction; and the processing unit is further configured to determine second direction information according to the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity, the second direction information being used to indicate a current direction.

[0021] In an implementation manner, the first direction information is obtained by using a gyroscope to find the north.

[0022] In an implementation manner, the first direction information is obtained by using the earth magnetic field.

[0023] In an implementation manner, the second direction information comprises an angle of a to-be-detected direction; the first angular velocity, the second angular velocity, the third angular velocity, the fourth angular velocity and the direction information of the to-be-detected direction satisfy the following formula one:

[0024]

[0025] wherein ω1 represents the first angular velocity, ω2 represents the second angular velocity, ω3 represents the third angular velocity, ω4 represents the fourth angular velocity, represents the angle of the to-be-detected direction, θ1 represents an included angle between the first direction and the to-be-detected direction, θ2 represents an included angle between the second direction and the to-be-detected direction, θ3 represents an included angle between the third direction and the to-be-detected direction, θ4 represents an included angle between the fourth direction and the to-be-detected direction, and ω ie represents the angular velocity of the earth rotation, L represents a local latitude, and ε F represents a measurement zero offset value of the gyroscope.

[0026] In an implementation manner, the second direction information comprises an angle of a to-be-detected direction; the second direction information is determined according to the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity, comprising: a vector X satisfying the following formula two is determined according to the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity:

[0027] X=(B T B)-1 B T A Formula Two

[0028] wherein, ω1 represents a first angular velocity, ω2 represents a second angular velocity, ω3 represents a third angular velocity, ω4 represents a fourth angular velocity, θ1 represents an included angle between a first direction and a direction to be detected, θ2 represents an included angle between a second direction and the direction to be detected, θ3 represents an included angle between a third direction and the direction to be detected, and θ4 represents an included angle between a fourth direction and the direction to be detected. According to the vector X, the angle of the direction to be detected is determined; wherein the angle of the direction to be detected satisfies the following Formula Three:

[0029]

[0030] wherein, X[2] represents a first item of the vector X, and X[1] represents a second item of the vector X.

[0031] In a third aspect, a direction detection apparatus is provided, including a processor and an interface, the processor receiving or sending data through the interface, and the processor being configured to implement the method provided in the first aspect or any implementation manner of the first aspect.

[0032] In a fourth aspect, a micro-electro-mechanical system (MEMS) gyro north finder is provided, including a MEMS gyroscope and the direction detection apparatus provided in the second aspect or any implementation manner of the second aspect, or the direction detection apparatus provided in the third aspect or any implementation manner of the third aspect.

[0033] In a fifth aspect, a fiber-optic gyroscope north finder is provided, including a fiber-optic gyroscope and the direction detection apparatus provided in the second aspect or any implementation manner of the second aspect, or the direction detection apparatus provided in the third aspect or any implementation manner of the third aspect.

[0034] In a sixth aspect, a computer readable storage medium is provided, the computer readable storage medium storing instructions, when the instructions are executed on a processor, implementing the method provided in the first aspect or any implementation manner of the first aspect.

[0035] In a seventh aspect, a computer program product is provided, the computer program product including instructions, when the instructions are executed on a processor, implementing the method provided in the first aspect or any implementation manner of the first aspect. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 One of the schematic diagrams of a direction detection method based on a gyro four-position method provided by an embodiment of the present application;

[0037] Figure 2Fig. 2 is a schematic diagram of a method for azimuth detection based on a gyro four-position method according to an embodiment of the present application;

[0038] Figure 3 Fig. 3 is a schematic diagram of a method for azimuth detection based on a gyro four-position method according to an embodiment of the present application;

[0039] Figure 4 Fig. 4 is a flowchart of a method for azimuth detection according to an embodiment of the present application;

[0040] Figure 5 Fig. 5 is a schematic diagram of a gyro north finder according to an embodiment of the present application;

[0041] Figure 6 Fig. 6 is a schematic diagram of an azimuth detection device according to an embodiment of the present application;

[0042] Figure 7 Fig. 7 is a schematic diagram of an azimuth detection device according to an embodiment of the present application. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present application will be described below with reference to the drawings.

[0044] In order to facilitate understanding of the technical solutions provided in the embodiments of the present application, first, the related technologies involved in the embodiments of the present application will be introduced:

[0045] A gyro north finder refers to a device that measures the angular velocity of the earth's rotation through an inertial device (i.e., a gyroscope) and then determines the azimuth. For example, a gyro north finder can use a gyro four-position method to determine the azimuth.

[0046] Specifically, in the process of using the traditional gyro four-position method to find north, first, the gyroscope is placed on a turning mechanism, and then the gyroscope data is sampled at four positions spaced 90° apart, and then the azimuth information is determined according to the sampled data.

[0047] For example, it is assumed that the direction angle of the north direction is 0°, and clockwise is positive (i.e., the direction angle of the east direction is 90°, the direction angle of the south direction is 180°, and the direction angle of the west direction is 270°).

[0048] It should be noted that, unless otherwise specified, the "north direction", "east direction", "south direction" and "west direction" appearing in the following can be understood as "north direction", "east direction", "south direction" and "west direction".

[0049] Further, in the process of confirming the azimuth, for example, Figure 1As shown, the earth rotation angular velocity is measured at the initial position (i.e., direction P1) and other three positions corresponding to the direction P1 (i.e., directions P2, P3 and P4), respectively, to obtain ω1, ω2, ω3 and ω4. Among them, ω1 is the earth rotation angular velocity measured at the direction P1, ω2 is the earth rotation angular velocity measured at the direction P2, ω3 is the earth rotation angular velocity measured at the direction P3, and ω4 is the earth rotation angular velocity measured at the direction P4.

[0050] It should be noted that in actual application, the process of rotating the gyroscope to a certain direction can also be understood as rotating the gyroscope to a certain position. Therefore, the "direction" referred to in the embodiments of the present application can also be represented as "position", that is, the "position" referred to in the "gyroscope four-position method" above. For example, in actual application, the "direction P1" in the embodiments of the present application can also be represented as "position P1", the "direction P2" can also be represented as "position P2", and so on.

[0051] Further, since ω1, ω2, ω3 and ω4 satisfy the following formula (1):

[0052]

[0053] Among them, ω ie represents the earth rotation angular velocity, L represents the local latitude, and ε t1 , ε t2 , ε t3 and ε t4 represent the gyroscope measurement zero offset values at the four positions, which can be taken as equal parameters in actual application. t1 , ε t2 , ε t3 and ε t4 .

[0054] Therefore, it can be known that the azimuth angle of the direction P1 satisfies the following formula (2):

[0055]

[0056] That is, by bringing ω1, ω2, ω3 and ω4 into formula (2), the azimuth angle of the direction P1 In this way, the current azimuth information can be obtained.

[0057] It can be understood that in the above formula (1), ω ie , L, ε t1 , ε t2 , ε t3 and ε t4These parameters can cancel each other in the subsequent calculation (i.e., in formula (2)). In addition, it can be understood that, although the above parameters can cancel each other in the subsequent calculation, the current latitude of the actual position of the gyroscope has an impact on the calculation result. For example, the error of the calculation result obtained near the equator and the calculation result obtained in high latitude areas can be different.

[0058] It can be seen that the above related technology can use the earth rotation angular velocity measured by the gyroscope at four positions to determine the current orientation information. However, the four-position rotation scheme of this technology has the problem of low measurement accuracy in actual application.

[0059] In view of the above technical problems, in the embodiments of the present application, it is considered that, in the case that rough orientation information (hereinafter referred to as "first orientation information") can be obtained, four directions (hereinafter referred to as "first direction", "second direction", "third direction" and "fourth direction") can be determined according to the first orientation information. Among them, the first orientation information can be understood as orientation information with larger error, for example, the orientation information indicates the four directions of east, south, west and north, but the indicated direction has a certain error. Specifically, the first orientation information is used to indicate at least the east direction and the west direction. In addition, the above four directions satisfy the following conditions: the first direction is the direction corresponding to the east direction minus a preset degree, the second direction is the direction corresponding to the east direction plus a preset degree, the third direction is the direction corresponding to the west direction minus a preset degree, and the fourth direction is the direction corresponding to the west direction plus a preset degree. Among them, the preset degree is less than 90°. Then, the measured earth rotation angular velocity (hereinafter referred to as "first angular velocity", "second angular velocity", "third angular velocity" and "fourth angular velocity") when the gyroscope is turned to the first direction, the second direction, the third direction and the fourth direction is determined. Then, according to the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity, the second orientation information used to indicate the current orientation is determined. In this way, more accurate orientation information (i.e., second orientation information) can be obtained.

[0060] For example, Figure 2As shown, the four directions (north, south, east, and west) in the rough orientation information are referred to as "proposed east," "proposed south," "proposed west," and "proposed north." Furthermore, using this orientation information, the first direction P1, the second direction P2, the third direction P3, and the fourth direction P4 can be determined. Specifically, the first direction P1 corresponds to the proposed east direction minus a preset degree ψ; the second direction P2 corresponds to the proposed east direction plus a preset degree ψ; the third direction P3 corresponds to the proposed west direction minus a preset degree ψ; and the fourth direction P4 corresponds to the proposed west direction plus a preset degree ψ, where ψ < 90°. Then, by rotating the gyroscope to the first direction P1, the second direction P2, the third direction P3, and the fourth direction P4 respectively, the Earth's rotation angular velocity corresponding to each of the four directions can be obtained. Based on these Earth rotation angular velocities, more precise orientation information can be determined.

[0061] The principles of the technical solutions provided in the embodiments of this application are described below:

[0062] In the four-position method of a gyroscope, such as Figure 3 As shown, assume the initial orientation of the gyroscope (for example, the initial orientation can be the orientation to be detected). Figure 3 The azimuth angle (with P as the initial direction) is The four directions used ( Figure 3 Taking P1, P2, P3, and P4 as examples, their rotation angles relative to the initial direction are θ1, θ2, θ3, and θ4, respectively. That is, the azimuth angles in the four directions are...

[0063] Therefore, it can be concluded that:

[0064]

[0065] Where ω1, ω2, ω3, and ω4 are the Earth's rotational angular velocities measured in directions P1, P2, P3, and P4, respectively, and ω ie ε represents the Earth's rotational angular velocity, L represents the local latitude, and ε represents the Earth's rotational angular velocity. t1 ε t2 ε t3 and ε t4 These represent the zero bias values ​​of the gyroscope measurement at the four positions. In practical applications, ε can be used to... t1 ε t2 ε t3 and ε t4 As equal parameters.

[0066] Furthermore, given θ3 = θ1 + π and θ4 = θ2 + π, we can obtain:

[0067]

[0068] In addition, according to the error synthesis principle, it can be known that:

[0069]

[0070] wherein, σ represents the standard deviation of the error of the measured value of the azimuth angle , σ represents the standard deviation of the error of ω1, σ represents the standard deviation of the error of ω2, σ represents the standard deviation of the error of ω3, and σ ω4 represents the standard deviation of the error of ω4.

[0071] wherein, ω1, ω2, ω3 and ω4 can be understood as independent and equal-precision measured values in a short time, and thus can be considered as: It can be further known that:

[0072]

[0073] that is,

[0074] After substituting into the above formula (7), the following formula (8) is obtained:

[0075]

[0076] Simplifying formula (8), the following formula (9) is obtained:

[0077]

[0078] It can be known from formula (9) that:

[0079] On the one hand, in the azimuth detection method of the related art, since the interval between the four directions is 90°, θ1=0° and θ2=90° are substituted into formula (9), and the following formula (10) is obtained:

[0080]

[0081] That is, in the azimuth detection method of the related art, the standard deviation of the error of the measured value of the azimuth angle calculated is

[0082] On the other hand, when the technical solution provided by the embodiments of the present application is adopted, since the four directions satisfy the following conditions: the first direction is a direction corresponding to the east direction minus a preset degree, the second direction is a direction corresponding to the east direction plus a preset degree, the third direction is a direction corresponding to the west direction minus a preset degree, and the fourth direction is a direction corresponding to the west direction plus a preset degree. Wherein, the preset degree ψ is less than 90°. Therefore, θ1=0° and θ2=90° are substituted into formula (9), and the following formula (11) is obtained: Substitute into equation (9), we get:

[0083]

[0084] As can be seen from equation (11), when the technical solution provided by the embodiments of the present application is adopted, the error can be reduced by times at most, that is, the error can be reduced by about 29.3% (i.e. when ψ is 0°, but it can be understood that ψ cannot be 0° in actual application).

[0085] Specifically, as can be seen from equation (11), when ψ changes in the range of (0°, 90°), the smaller ψ is to 0°, the smaller the error of the measured value of the azimuth angle is; the larger ψ is to 90°, the larger the error of the measured value of the azimuth angle is. For example, when ψ = 20°, the north-seeking error can be reduced by 24.75% in theory.

[0086] The technical solution provided by the embodiments of the present application will be described in detail below with examples. Specifically, the embodiments of the present application provide a method for azimuth detection. The method can be applied to various azimuth detection devices for azimuth detection by using a gyroscope. For example, the azimuth detection device can be a software or hardware device for controlling the turning of the gyroscope in a gyroscopic north finder and obtaining detection data.

[0087] In actual application, the functions of the azimuth detection device can be realized by all or part of the software or hardware in the gyroscopic north finder. Or, when the azimuth detection device is independent of the gyroscopic north finder, the functions of the azimuth detection device can be realized by all or part of the software or hardware in a desktop computer, a tablet computer, a desktop computer, a laptop computer, a handheld computer, a notebook computer, an ultra-mobile personal computer, a netbook, and an electronic device such as a cellular phone, a personal digital assistant, and an augmented reality / virtual reality device.

[0088] Specifically, as shown in Figure 4 , the method for azimuth detection can include:

[0089] S101, the azimuth detection device obtains first azimuth information.

[0090] The first azimuth information is used to indicate the east direction and the west direction.

[0091] The first azimuth information can be azimuth information with low precision.

[0092] In an implementation manner, the first azimuth information can be azimuth information obtained by using the earth magnetic field.

[0093] For example, in actual application, the azimuth detection device can determine the first azimuth information by detecting the direction of a compass or by detecting the value of a magnetometer.

[0094] In another implementation, the first azimuth information can be the azimuth information obtained by using a gyro to find north.

[0095] For example, in actual application, the azimuth detection device can determine the first azimuth information by detecting the direction of a compass or by detecting the value of a magnetometer. Figure 1 According to the corresponding detection process, the first azimuth information is determined by using the methods shown in the above formulas (1) and (2).

[0096] S102, the azimuth detection device determines a first direction, a second direction, a third direction, and a fourth direction according to the first azimuth information.

[0097] The first direction is a direction corresponding to the east direction minus a preset degree, the second direction is a direction corresponding to the east direction plus the preset degree, the third direction is a direction corresponding to the west direction minus the preset degree, and the fourth direction is a direction corresponding to the west direction plus the preset degree. The preset degree is less than 90°.

[0098] For ease of description, in the embodiments of the present application, the east direction indicated by the first azimuth information is referred to as a "pseudo-east direction", and the west direction indicated by the first azimuth information is referred to as a "pseudo-west direction". As shown in the following formula (3), the first direction P1 is a direction corresponding to the pseudo-east direction minus a preset degree ψ, the second direction P2 is a direction corresponding to the pseudo-east direction plus the preset degree ψ, the third direction P3 is a direction corresponding to the pseudo-west direction minus the preset degree ψ, and the fourth direction P4 is a direction corresponding to the pseudo-west direction plus the preset degree ψ, wherein ψ < 90°. Figure 2

[0099] In order to improve the detection accuracy, in an implementation, the preset degree in the embodiments of the present application is less than or equal to 20°. In this way, it can be ensured that the four selected directions are close to the east-west direction, thereby ensuring that the four-position north finding is performed near the east-west direction.

[0100] S103, the azimuth detection device determines a first angular velocity, a second angular velocity, a third angular velocity, and a fourth angular velocity.

[0101] The first angular velocity, the second angular velocity, the third angular velocity, and the fourth angular velocity are respectively the angular velocities of the earth rotation measured when the gyroscope is rotated to the first direction, the second direction, the third direction, and the fourth direction.

[0102] ​For example, the azimuth detection apparatus can control the gyro north seeker to rotate the gyroscope to the first direction, the second direction, the third direction and the fourth direction respectively, and obtain the earth rotation angular velocity (i.e., the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity) measured by the gyro north seeker in the four directions.

[0103] It can be understood that, in actual application, the order of rotating the gyroscope can be set arbitrarily according to actual needs. For example, the gyroscope is first rotated to the second direction, then rotated to the fourth direction, then rotated to the first direction, and then rotated to the third direction, and the earth rotation angular velocity measured in the four directions is obtained in turn. The order of rotating the gyroscope can not be limited in the embodiments of the present application.

[0104] The specific implementation process of measuring the earth rotation angular velocity can refer to the related art, and the embodiments of the present application will not be repeated here.

[0105] In an implementation manner, the method can be applied to a MEMS gyro north seeker. Alternatively, the method can be applied to a fiber-optic gyro north seeker. At this time, the azimuth detection apparatus can be included in the MEMS gyro north seeker or the fiber-optic gyro north seeker.

[0106] S104, the azimuth detection apparatus determines second azimuth information according to the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity.

[0107] The second azimuth information is used to indicate the current azimuth.

[0108] In an implementation manner, the second azimuth information can include the angle of the direction to be detected.

[0109] Further, the first angular velocity ω1, the second angular velocity ω2, the third angular velocity ω3, the fourth angular velocity ω4 and the angle The following formula (11) is satisfied:

[0110]

[0111] ω1 represents the first angular velocity, ω2 represents the second angular velocity, ω3 represents the third angular velocity, ω4 represents the fourth angular velocity, represents the angle of the direction to be detected, θ1 represents the included angle between the first direction and the direction to be detected, θ2 represents the included angle between the second direction and the direction to be detected, θ3 represents the included angle between the third direction and the direction to be detected, θ4 represents the included angle between the fourth direction and the direction to be detected, and ω ie represents the earth rotation angular velocity, L represents the local latitude, and ε F represents the gyro measurement zero offset value.

[0112] In other words, after obtaining the first angular velocity, the second angular velocity, the third angular velocity, and the fourth angular velocity through S103, the angle of the direction to be detected can be obtained by substituting the first angular velocity, the second angular velocity, the third angular velocity, and the fourth angular velocity into the above equation (11). This allows us to determine the second location information.

[0113] In one possible design, considering that: as can be seen from equation (11):

[0114]

[0115] In addition, it can be known that:

[0116]

[0117] Where X[1] represents the first term of vector X, and X[2] represents the second term of vector X.

[0118] Therefore, we can first calculate vector X, and then obtain the angle of the direction to be detected based on vector X.

[0119] Therefore, S104 may specifically include:

[0120] S1041. Based on the first angular velocity, the second angular velocity, the third angular velocity, and the fourth angular velocity, determine the vector X that satisfies the following equation (14).

[0121] X = (B T B) -1 B T Formula A (14)

[0122] in, ω1 represents the first angular velocity, ω2 represents the second angular velocity, ω3 represents the third angular velocity, ω4 represents the fourth angular velocity, θ1 represents the angle between the first direction and the direction to be detected, θ2 represents the angle between the second direction and the direction to be detected, θ3 represents the angle between the third direction and the direction to be detected, and θ4 represents the angle between the fourth direction and the direction to be detected.

[0123] S1042. Determine the angle of the direction to be detected based on vector X.

[0124] Among them, the angle of the direction to be detected The following equation (15) must be satisfied:

[0125]

[0126] Specifically, in an implementation manner, after the second orientation information is obtained through the process of S104, the second orientation information can be taken as a measurement result, so that the measurement result can be output to a display device for a technician to know the measurement result, or the measurement result can also be output to other devices for subsequent processing.

[0127] In another implementation manner, after the second orientation information is obtained through the process of S104, the first orientation information and the second orientation information can also be fused, so as to further improve the accuracy of the measurement result.

[0128] Specifically, the method further includes:

[0129] S105, the orientation detection device determines a measurement result of the to-be-detected direction according to the first orientation angle and the second orientation angle.

[0130] The first orientation angle is an angle of the to-be-detected direction included in the first orientation information. The second orientation angle is an angle of the to-be-detected direction included in the second orientation information.

[0131] For example, the first orientation angle and the second orientation angle can be weighted and summed to obtain the measurement result of the to-be-detected direction. Then, the measurement result can be output to a display device for a technician to know the measurement result, or the measurement result can also be output to other devices for subsequent processing.

[0132] In the above orientation detection method provided by the embodiments of the present application, after the first orientation information with low accuracy is obtained, four directions (i.e., the first direction is a direction corresponding to the east direction minus a preset angle, the second direction is a direction corresponding to the east direction plus the preset angle, the third direction is a direction corresponding to the west direction minus the preset angle, and the fourth direction is a direction corresponding to the west direction plus the preset angle. The preset angle is less than 90°) that meet the condition can be determined according to the first orientation information. Then, the earth rotation angular velocity (i.e., the first angular velocity, the second angular velocity, the third angular velocity, and the fourth angular velocity) measured when the gyroscope is turned to the first direction, the second direction, the third direction, and the fourth direction is determined. Then, the second orientation information used to indicate the current orientation is determined according to the first angular velocity, the second angular velocity, the third angular velocity, and the fourth angular velocity. In this way, more accurate orientation information (i.e., the second orientation information) can be obtained.

[0133] For example, when the orientation detection method provided by the embodiments of the present application is applied to a MEMS gyro north seeker, the actual measurement results show that when the preset angle is 5°, the north-seeking error is reduced by 26.4%; and when the preset angle is 20°, the north-seeking error is reduced by 22.6%.

[0134] Based on the above method embodiments, the device provided by the embodiments of the present application is described below. As shown in Figure 5 FIG. 1 is a structural schematic diagram of a gyro north finder provided by an embodiment of the present application. The gyro north finder 20 can include a gyroscope 201, a rotating mechanism 202, and an azimuth detection device 203.

[0135] The gyroscope 201 is configured to rotate to a corresponding direction under the driving of the rotating mechanism 202. The gyroscope 201 can be a MEMS gyroscope or a fiber-optic gyroscope, or the gyroscope 201 can also be another type of gyroscope.

[0136] The azimuth detection device 203 can be configured to control the rotating mechanism 202 to drive the gyroscope 201 to the corresponding direction, and can be configured to acquire and process the earth rotation angular velocity measured by the gyroscope 201 after the gyroscope 201 rotates to the corresponding direction, and can be configured to detect the azimuth according to the method shown in Figure 4

[0137] In actual applications, the gyro north finder 20 can be used as a functional module in a navigation module for realizing a navigation function, so as to provide the azimuth information for the navigation module. In addition, the gyro north finder 20 can also be used as an independent product to provide the azimuth information for users.

[0138] In addition, as shown in Figure 6 FIG. 3 is a structural schematic diagram of an azimuth detection device provided by an embodiment of the present application. Specifically, the azimuth detection device 30 can be a chip or a system on chip, and the azimuth detection device 30 can be configured to realize the functions of the azimuth detection device in Figure 4

[0139] In one implementation manner, the functions of the azimuth detection device 30 can be realized by a software or hardware module in the gyro north finder, and at this time, the azimuth detection device 30 can be understood as the azimuth detection device 20 in Figure 5

[0140] In another implementation manner, the functions of the azimuth detection device 30 can be realized by a software or hardware module independent of the gyro north finder. For example, the functions of the azimuth detection device can be realized by all or part of the software or hardware in a desktop computer, a tablet computer, a desktop computer, a laptop computer, a handheld computer, a notebook computer, an ultra-mobile personal computer, a netbook, and an electronic device such as a cellular phone, a personal digital assistant, and an augmented reality / virtual reality device.

[0141] Specifically, the azimuth detection device 30 can include:

[0142] ​​​The acquisition unit 301 is configured to acquire first orientation information, and the first orientation information is used to indicate an east direction and a west direction.

[0143] The processing unit 302 is configured to determine a first direction, a second direction, a third direction and a fourth direction according to the first orientation information, wherein the first direction is a direction corresponding to the east direction minus a preset degree, the second direction is a direction corresponding to the east direction plus the preset degree, the third direction is a direction corresponding to the west direction minus the preset degree, and the fourth direction is a direction corresponding to the west direction plus the preset degree, and the preset degree is less than 90°.

[0144] The processing unit is further configured to determine a first angular velocity, a second angular velocity, a third angular velocity and a fourth angular velocity, wherein the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity are respectively measured angular velocities of the earth rotation when the gyroscope rotates to the first direction, the second direction, the third direction and the fourth direction respectively.

[0145] The processing unit is further configured to determine second orientation information according to the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity, and the second orientation information is used to indicate a current orientation.

[0146] In an implementation manner, the acquisition unit 301 is configured to acquire the first orientation information, and the acquisition unit 301 is configured to acquire orientation information obtained by using a gyrosphere four-position method.

[0147] In an implementation manner, the acquisition unit 301 is configured to acquire the first orientation information, and the acquisition unit 301 is configured to acquire orientation information obtained by using a compass.

[0148] In an implementation manner, the second orientation information includes an angle of a to-be-detected direction, and the first angular velocity, the second angular velocity, the third angular velocity, the fourth angular velocity and the orientation information of the to-be-detected direction satisfy the following formula I:

[0149]

[0150] wherein ω1 represents the first angular velocity, ω2 represents the second angular velocity, ω3 represents the third angular velocity, ω4 represents the fourth angular velocity, represents the angle of the to-be-detected direction, θ1 represents an included angle between the first direction and the to-be-detected direction, θ2 represents an included angle between the second direction and the to-be-detected direction, θ3 represents an included angle between the third direction and the to-be-detected direction, θ4 represents an included angle between the fourth direction and the to-be-detected direction, and ω ie represents the angular velocity of the earth rotation, L represents a local latitude, and ε F represents a gyroscope measurement zero offset value.

[0151] In an implementation, the second orientation information includes an angle of the direction to be detected; the processing unit 302 is further configured to determine the second orientation information according to the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity, including:

[0152] The processing unit 302 is further configured to determine a vector X satisfying the following Formula Two according to the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity:

[0153] X = (B T B) -1 B T A Formula Two

[0154] wherein, ω1 represents the first angular velocity, ω2 represents the second angular velocity, ω3 represents the third angular velocity, ω4 represents the fourth angular velocity, θ1 represents an included angle between the first direction and the direction to be detected, θ2 represents an included angle between the second direction and the direction to be detected, θ3 represents an included angle between the third direction and the direction to be detected, and θ4 represents an included angle between the fourth direction and the direction to be detected;

[0155] The processing unit 302 is further configured to determine the angle of the direction to be detected according to the vector X; wherein the angle of the direction to be detected satisfies the following Formula Three:

[0156]

[0157] wherein, X[2] represents a first item of the vector X, and X[1] represents a second item of the vector X.

[0158] Figure 7 Another structure diagram of an orientation detection device provided by the embodiment is shown in FIG. 4. The orientation detection device 40 can be a chip or a system on chip.

[0159] In an implementation, the functions of the orientation detection device 40 can be realized by hardware modules in a gyroscopic north finder, and in this case, the orientation detection device 40 can be understood as Figure 5 the orientation detection device 20 in the gyroscopic north finder.

[0160] In another implementation, the functions of the orientation detection device 40 can be realized by software or hardware modules independent of the gyroscopic north finder. For example, the functions of the orientation detection device can be realized by software or hardware of all or part of electronic devices such as desktop computers, tablet computers, desktop computers, laptop computers, handheld computers, notebook computers, ultra-mobile personal computers, netbooks, and cellular phones, personal digital assistants, and augmented reality / virtual reality devices.

[0161] The orientation detection device 40 may include some or all of the following components: processor 401, communication line 402, memory 403, and at least one communication interface 404.

[0162] The processor 401 is used to execute this embodiment. Figure 4 The method shown refers to all or part of the steps performed by the orientation detection device.

[0163] Specifically, processor 401 may include a general-purpose central processing unit (CPU), and processor 401 may also include a microprocessor, a field-programmable gate array (FPGA), a digital signal processor (DSP), or an application-specific integrated circuit (ASIC), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0164] In a specific implementation, as one example, processor 401 may include one or more CPUs, for example... Figure 7 CPU0 and CPU1 in the CPU.

[0165] In a specific implementation, as one embodiment, device 40 may include multiple processors, for example... Figure 7 Processors 401 and 408 are mentioned. Each of these processors can be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. A processor here can refer to one or more devices, circuits, and / or processing cores used to process, for example, data (computer program instructions).

[0166] In addition, the memory 403 can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically EPROM (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM) used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), double data rate synchronous dynamic RAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM), and direct rambus RAM (DR RAM). The memory 403 can exist independently, and be connected to the processor 401 through the communication line 402. The memory 403 can also be integrated with the processor 401.

[0167] The memory 403 stores computer instructions. The processor 401 can execute the computer instructions stored in the memory 403 to perform all or part of the steps of the method provided in the embodiments.

[0168] Optionally, the computer execution instructions in the embodiments can also be referred to as application program codes, which are not specifically limited in the embodiments.

[0169] In addition, the communication interface 404 uses any transceiver-like device for communicating with other devices or communication networks, such as an Ethernet, a radio access network (RAN), a wireless local area networks (WLAN), etc.

[0170] In addition, the communication line 402 is used to connect various components in the orientation detection device 40. Specifically, the communication line 402 can include a data bus, a power supply bus, a control bus, and a status signal bus, etc. However, for the purpose of clear illustration, all kinds of buses are marked as the communication line 402 in the figure.

[0171] In a particular implementation, as an example, the orientation detection apparatus 40 can further include an output device 407 and an input device 406. The output device 407 can be in communication with the processor 401 and can present information in a variety of manners. The input device 406 can be in communication with the processor 401 and can receive input in a variety of ways.

[0172] In addition, the orientation detection apparatus 40 can further include a storage medium 405. The storage medium 405 is used to store computer instructions and various data for implementing the technical solutions of the present embodiment. In order for the orientation detection apparatus 40 to execute the above-mentioned method of the present embodiment, the computer instructions and various data stored in the storage medium 405 are loaded into the memory 403, so that the processor 401 can execute the computer instructions stored in the memory 403 to execute the method provided by the present embodiment.

[0173] The method steps in the present embodiment can be implemented by hardware or by the processor executing software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in a RAM, a flash memory, a ROM, a PROM, an EPROM, an EEPROM, a register, a hard disk, a mobile hard disk, a CD-ROM, or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor, so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in the orientation detection apparatus. Of course, the processor and the storage medium can also exist as discrete components in the orientation detection apparatus.

[0174] In the above embodiments, all or part can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part can be implemented in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer programs or instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments are performed. The computer can be a general purpose computer, a special purpose computer, a computer network, a communication device, a user equipment or other programmable device. The computer programs or instructions can be stored in a computer readable storage medium or transferred from one computer readable storage medium to another computer readable storage medium, for example, the computer programs or instructions can be transferred from one website site, computer, server or data center to another website site, computer, server or data center through wired or wireless manner. The computer readable storage medium can be any available medium accessible by a computer or a data storage device such as a server, data center and the like integrated with one or more available media. The available media can be a magnetic medium, such as a floppy disk, a hard disk, a magnetic tape; an optical medium, such as a digital video disc (digital video disc, DVD); and a semiconductor medium, such as an SSD.

[0175] In the embodiments, the terms and / or descriptions among different implementation manners are consistent and can be referred to each other if there is no special description and logical conflict, and the technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0176] In the embodiments, "at least one" means one or more, "multiple" means two or more, and other quantifiers are similar. The association relationship of the associated objects is described by "and / or", which means that there can be three relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. In addition, for the elements (element) appearing in the singular form "a", "an" and "the", unless the context clearly specifies otherwise, it does not mean "one or only one", but means "one or more than one". For example, "a device" means one or more such devices. Furthermore, "at least one of" means one or any combination of the subsequent associated objects, for example, "at least one of A, B and C" includes A, B, C, AB, AC, BC or ABC. In the literal description of the embodiments, the character " / ", generally represents that the preceding and following associated objects are in an "or" relationship; in the formulas of the embodiments, the character " / ", represents that the preceding and following associated objects are in a "division" relationship.

Claims

1. An orientation detection method, characterized by, The method comprises: obtaining first orientation information; the first orientation information is used for indicating east direction and west direction; determining first direction, second direction, third direction and fourth direction according to the first orientation information; wherein the first direction is a direction corresponding to the east direction minus a preset degree, the second direction is a direction corresponding to the east direction plus the preset degree, the third direction is a direction corresponding to the west direction minus the preset degree, and the fourth direction is a direction corresponding to the west direction plus the preset degree; the preset degree is less than 90°; determining first angular velocity, second angular velocity, third angular velocity and fourth angular velocity; wherein the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity are respectively the angular velocity of the earth rotation measured when the gyroscope rotates to the first direction, the second direction, the third direction and the fourth direction respectively; determining second orientation information according to the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity; the second orientation information is used for indicating current orientation.

2. The method of claim 1, wherein, The first orientation information is obtained by using a gyroscope to find north.

3. The method of claim 1, wherein, The first orientation information is obtained by using the earth magnetic field.

4. The method according to any one of claims 1 to 3, characterized in that, The second orientation information includes the angle of the direction to be detected; the first angular velocity, the second angular velocity, the third angular velocity, the fourth angular velocity and the orientation information of the direction to be detected satisfy the following formula one: wherein ω1 represents the first angular velocity, ω2 represents the second angular velocity, ω3 represents the third angular velocity, and ω4 represents the fourth angular velocity, represents the angle of the direction to be detected, θ1 represents the included angle between the first direction and the direction to be detected, θ2 represents the included angle between the second direction and the direction to be detected, θ3 represents the included angle between the third direction and the direction to be detected, and θ4 represents the included angle between the fourth direction and the direction to be detected, ω ie represents the angular velocity of the earth rotation, L represents the local latitude, and ε F represents the gyroscopic measurement zero offset value.

5. The method according to any one of claims 1 to 4, characterized in that, The second orientation information includes the angle of the direction to be detected; the determination of the second orientation information according to the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity comprises: determining vector X satisfying the following formula two according to the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity: X = (B T B) -1 B T A formula two wherein, ω1 represents the first angular velocity, ω2 represents the second angular velocity, ω3 represents the third angular velocity, ω4 represents the fourth angular velocity, θ1 represents the included angle between the first direction and the direction to be detected, θ2 represents the included angle between the second direction and the direction to be detected, θ3 represents the included angle between the third direction and the direction to be detected, and θ4 represents the included angle between the fourth direction and the direction to be detected. According to the vector X, the angle of the direction to be detected is determined; wherein the angle of the direction to be detected Satisfies the following formula three: Wherein, X[2] represents the first item of vector X, and X[1] represents the second item of vector X.

6. The method according to any one of claims 1 to 5, characterized in that, The method further comprises: determining the measurement result of the direction to be detected according to the first azimuth angle and the second azimuth angle; wherein the first azimuth angle is the angle of the direction to be detected included in the first orientation information; and the second azimuth angle is the angle of the direction to be detected included in the second orientation information.

7. The method according to any one of claims 1 to 6, characterized in that, The method is applied to a micro-electro-mechanical system (MEMS) gyroscope for finding north, or the method is applied to an optical fiber gyroscope for finding north.

8. An orientation detection device, characterized by The orientation detection device comprises: an acquisition unit, configured to obtain first orientation information; the first orientation information is used for indicating east direction and west direction; a processing unit, configured to determine first direction, second direction, third direction and fourth direction according to the first orientation information; wherein the first direction is a direction corresponding to the east direction minus a preset degree, the second direction is a direction corresponding to the east direction plus the preset degree, the third direction is a direction corresponding to the west direction minus the preset degree, and the fourth direction is a direction corresponding to the west direction plus the preset degree; the preset degree is less than 90°; The processing unit is further configured to determine a first angular velocity, a second angular velocity, a third angular velocity and a fourth angular velocity, wherein the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity are respectively measured angular velocities of the earth rotation when the gyroscope is rotated to the first direction, the second direction, the third direction and the fourth direction respectively. The processing unit is further configured to determine a second orientation information according to the first angular velocity, the second angular velocity, the third angular velocity and the fourth angular velocity, wherein the second orientation information is used to indicate a current orientation.

9. An orientation detection device, characterized by A device comprising a processor and an interface, wherein the processor is configured to receive or send data via the interface, and the processor is configured to implement the method according to any one of claims 1-7.

10. A microelectromechanical system (MEMS) gyroscopic north seeker, characterized by, A device comprising: a MEMS gyroscope and the orientation detection apparatus according to claim 8 or 9.

11. An optical fiber gyroscope north seeker, characterized by, A device comprising: an optical fiber gyroscope and the orientation detection apparatus according to claim 8 or 9.

12. A computer-readable storage medium, characterized in that, A computer readable storage medium storing instructions, which when executed on a processor, implement the method according to any one of claims 1-7.

13. A computer program product, characterised in that, A computer program product comprising instructions, which when executed on a processor, implement the method according to any one of claims 1-7.

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