A dual vector geomagnetic gravity wireless attitude measurement device based on rotational motion

Abstract

The application belongs to the technical field of attitude measurement, and particularly relates to a geomagnetic gravity double-vector wireless attitude measurement device based on rotary motion. The device comprises a base, a sensor platform rotor rotatably arranged on the base, a sensor PCB arranged on the sensor platform rotor, a single-axis accelerometer and a magnetometer arranged on the sensor PCB, the sensitive axes of the single-axis accelerometer and the magnetometer being coplanar and non-orthogonal to the rotation axis of the sensor platform rotor, a power mechanism for driving the rotation of the sensor platform rotor, and a rotor angle sensor for detecting the rotation angle of the sensor platform rotor. The application can measure complete geomagnetic gravity vector information through two single-axis sensors based on the rotary motion of the sensor mounting platform, and greatly reduces the sensor cost.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of attitude measurement, and particularly relates to a geomagnetic gravity double-vector wireless attitude measurement device based on rotary motion. BACKGROUND

[0002] The geomagnetic and gravity double-vector attitude measurement technology utilizes the natural characteristics of the geomagnetic field and the gravity field, and accurately measures the attitude information of an object through synchronous collection and analysis of the geomagnetic vector and the gravity vector. Unlike the traditional attitude measurement method relying on a gyroscope, the double-vector attitude measurement does not require a gyroscope, thereby reducing the hardware cost and power consumption, and can realize high-precision measurement without an external reference system in the manner of providing azimuth information through the geomagnetic vector and providing pitch and roll angles through the gravity vector. Although this technology is sensitive to magnetic interference, it performs excellently in a general magnetic environment and is widely applied to fields such as personal navigation, virtual reality, industrial detection and motion analysis. The advantage of this method lies in low cost, miniaturization, efficient measurement and high stability.

[0003] High-precision accelerometers and magnetometers are often in the form of single-axis packaging, and six separate devices need to be orthogonally placed and packaged to build a complete high-precision three-axis double-vector measurement device, which has high device and process costs. However, the existing measurement method and sensor structure can only use complete three-axis information to complete the measurement of vectors, which makes the measurement of high-precision geomagnetic and gravity vectors require high cost. SUMMARY

[0004] The application aims to provide a geomagnetic gravity double-vector wireless attitude measurement device based on rotary motion, which can measure complete geomagnetic and gravity vectors by using two single-axis sensors through the rotary motion of a sensor mounting platform, and overcome the problem of high cost of high-precision vector measurement systems.

[0005] The technical solution for achieving the application is as follows: a geomagnetic gravity double-vector wireless attitude measurement device based on rotary motion, comprising a base, a sensor platform rotor rotatably arranged on the base, a sensor PCB arranged on the sensor platform rotor, a single-axis accelerometer and a single-axis magnetometer arranged on the sensor PCB, the sensitive axes of the single-axis accelerometer and the single-axis magnetometer being coplanar and non-orthogonal to the rotation axis of the sensor platform rotor, a power mechanism for driving the rotation of the sensor platform rotor, and a rotor angle sensor for detecting the rotation angle of the sensor platform rotor.

[0006] Further, the device further comprises a rotor support arranged on the base, the sensor platform rotor is connected to the rotor support through a bearing, and the rotor angle sensor is arranged on one side of the rotor support.

[0007] Further, the electric slip ring has a rotor connected with the sensor platform rotor and a stator connected with the measuring device base.

[0008] Further, the power mechanism includes a motor, a synchronous belt wheel arranged at an output shaft of the motor and an end shaft of the sensor platform rotor, and a synchronous belt connecting the two synchronous belt wheels.

[0009] Further, a motor shield shell is arranged outside the motor.

[0010] Further, a controller is arranged, the rotor of the electric slip ring is connected with the sensor PCB through a signal line, and the stator of the electric slip ring, the motor and the rotor angle sensor are connected with the controller through wires.

[0011] Further, the controller is provided with a WiFi module.

[0012] A method for attitude measurement by the above-mentioned geomagnetic gravity dual-vector wireless attitude measurement device includes the following steps:

[0013] The controller receives the magnetometer signal, the accelerometer signal and the rotor angle signal, calculates the component information of the geomagnetic vector and the gravity vector in the measurement coordinate system according to the signals, and describes the magnetometer measurement signal and the accelerometer measurement signal as:

[0014] Y m =A m sin(ωt+φ m )+B m (1)

[0015] Y a =A a sin(ωt+φ a )+B a (2)

[0016] In the formula, Y m , Y a are the magnetic field values and acceleration values measured by the sensor, A m , A a are the amplitudes of the magnetometer sine signal and the accelerometer sine signal, ω is the rotation speed of the sensor, φ m , φ a are the phases of the two groups of sine signals, and B m , B a are the direct current components of the two groups of sine signals.

[0017] The rotor angle signal is a periodic sawtooth pulse signal:

[0018] Yd = kΘ (3)

[0019] In the formula, k is a proportional coefficient, and Θ is a rotor rotation angle.

[0020] When the controller receives the sampling signal of the sensor, the magnetic field and the accelerometer sine signal in a period are obtained according to the rotor angle signal, and the expression parameters in formula (1) and (2) are obtained through sine and fitting, so that the complete component information of the magnetic field and the gravity vector in the measurement coordinate system can be calculated:

[0021]

[0022]

[0023] The vector information calculated through formula (4) and (5) is used to calculate the measured attitude information by using a double vector attitude determination algorithm.

[0024] Compared with the prior art, the present application has the following advantages:

[0025] The present application is based on the rotation of the sensor installation platform, and the single-axis sensor placed non-orthogonally with the rotation axis is rotated at a constant speed in the measurement process. In a rotation period, the projection of the field component on the rotation plane on the sensitive axis of the sensor forms an alternating current form of a sine signal, and the projection of the field component on the rotation axis on the sensitive axis of the sensor forms a direct current signal. Through detection of the direct current signal and the alternating current signal, the field component in the rotation plane and the field component on the rotation axis can be restored, and the space field vector can be restored by combining the surface component and the axis component. Two single-axis sensors can be used to measure the complete geomagnetic gravity vector information. Compared with the prior art which needs two three-axis sensors, the sensor cost is greatly reduced. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a structure schematic diagram of the geomagnetic gravity double vector wireless attitude measurement device based on rotation motion of the present application.

[0027] Figure 2 It is a controller principle schematic diagram of the geomagnetic gravity double vector wireless attitude measurement device based on rotation motion of the present application.

[0028] Figure 3 It is a sensor arrangement schematic diagram of the geomagnetic gravity double vector wireless attitude measurement device based on rotation motion of the present application.

[0029] Figure 4 It is a magnetometer signal collection diagram of the geomagnetic gravity double vector wireless attitude measurement device based on rotation motion of the present application.

[0030] Figure 5This is an image of the accelerometer-collected signals from the geomagnetic gravity dual-vector wireless attitude measurement device based on rotational motion, as described in this invention.

[0031] Figure 6 This is a diagram of the rotor angle sensor acquiring signals of the geomagnetic gravity dual-vector wireless attitude measurement device based on rotational motion, as described in this invention.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1-Base, 2-Rotor support, 3-Motor shield, 4-Sensor platform rotor, 5-Sensor PCB board, 6-Motor, 7-Synchronous pulley, 8-Synchronous belt, 9-Electric slip ring, 10-Rotor angle sensor. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings.

[0035] This invention is a geomagnetic gravity dual-vector wireless attitude measurement device based on rotational motion, such as... Figure 1 As shown, the device includes a base 1 connected to the device under test, on which a rotor support 2 and a motor shield 3 are mounted. A sensor platform rotor 4 is mounted on the rotor support 2, and a sensor PCB board 5 is bolted to the sensor platform rotor 4. The sensor platform rotor 4 and the rotor support 2 are connected by bearings. A motor 6 is installed inside the motor shield 3, and the motor 6 and the motor shield 3 are connected by bolts. Synchronous pulleys 7 are mounted on both the output shaft of the motor 6 and the shaft end of the sensor platform rotor 4. The synchronous pulleys 7 are fastened to the shaft end by set screws. The sensor platform rotor 4 and the measuring device base 1 are connected by a synchronous belt 8; an electric slip ring 9 is also installed between the sensor platform rotor 4 and the measuring device base 1. The rotor of the electric slip ring 9 is connected to the sensor platform rotor 4 by a set screw, and the stator of the electric slip ring 9 is connected to the measuring device base 1 by bolts; a rotor angle sensor 10 is also fixed to the rotor support 2 by bolts; the rotor of the electric slip ring 9 is connected to the sensor PCB board 5 by a signal line and a wire; the stator of the electric slip ring 9, the motor 6, and the rotor angle sensor 10 are connected to the controller by wires, and the controller structure is as follows. Figure 2 As shown.

[0036] The working principle of this invention is as follows: Figure 3As shown, the single-axis accelerometer and magnetometer are mounted on the sensor PCB board 5 and fixed on the sensor platform rotor 4, the sensitive axis of the single-axis accelerometer and magnetometer is non-orthogonal to the rotor rotation axis, the sensitive axes of the single-axis accelerometer and magnetometer are coplanar, the angle between the sensitive axis of the magnetometer and the rotor rotation axis is θ1, and the angle between the sensitive axis of the accelerometer and the rotor rotation axis is θ2. When the attitude measurement is performed, the measurement device base 1 is fixed on the measured object, the motor 6 drives the sensor platform rotor 4 to rotate at a constant speed through the synchronous pulley 7 and the synchronous belt 8. Since the motor 6 itself and the magnetic field generated during operation, the motor 6 is placed in the motor shielding shell covered by the permalloy 4 to avoid the influence of the magnetic field on the geomagnetic field measurement. After the motor 6 drives the sensor platform rotor 4 to rotate, the magnetometer and the accelerometer on the sensor PCB board 5 start to measure the magnetic field and the gravity acceleration in real time. The sensor signal is transmitted through the wire, and the wire is connected to the slip ring stator wire through the rotor slip ring 9. The function of the rotor slip ring 9 is to connect and transmit the signal of the rotating body, which avoids the winding of the wire. The rotor angle sensor 10 measures the rotation angle of the sensor platform rotor 4 in real time. The wire of the motor 6, the wire of the slip ring 9 stator, and the wire of the rotor angle sensor 10 are connected to the controller as shown in Figure 2 .

[0037] In the controller, as shown in Figure 2 , the geomagnetic signal, the gravity acceleration signal, and the rotor angle signal are collected and converted into digital signals by the analog signal collection converter and transmitted to the main controller for calculation. The main controller sends the calculation results to the WiFi module and remotely transmits them to the operator. The operator's operation instructions for the measurement device can also be transmitted to the main controller through the WiFi module. The main controller analyzes the instructions and executes them. At the same time, the main controller sends the motor speed instruction to the motor controller to control the motor speed.

[0038] The main controller receives the magnetometer signal, the accelerometer signal, and the rotor angle signal as shown in Figure 4 , Figure 5 , Figure 6 . According to these signals, the components of the geomagnetic vector and the gravity vector in the measurement coordinate system can be calculated. The measurement coordinate system adopts the coordinate order of front-right-down, and the reference coordinate system adopts the coordinate order of north-east-ground. The rotation order from the reference coordinate system to the measurement coordinate system is z-y-x, that is, yaw-pitch-roll. Figure 4 , Figure 5 The magnetometer measurement signal and the accelerometer measurement signal are shown in

[0039] Y m = A m sin(ωt + φ m ) + B m(1)

[0040] Y a =A a sin(ωt+φ a )+B a (2)

[0041] In the formula, Y m Y a The magnetic field value and acceleration value measured by the sensor are respectively, A m A a ω represents the amplitude of the sinusoidal signal from the magnetometer and the accelerometer, respectively; ω is the angular velocity of the sensor rotation; and φ is the amplitude of the sinusoidal signal from the accelerometer. m φ a These represent the phases of the two sets of sinusoidal signals, B. m B a These are the DC components of two sets of sinusoidal signals. For example... Figure 6 As shown, the rotor angle signal is a periodic sawtooth pulse signal:

[0042] Y d =kΘ (3)

[0043] In the formula, k is the proportional coefficient and Θ is the rotor angle.

[0044] When the main controller receives the sampling signal from the sensor, it obtains the magnetic field and accelerometer sinusoidal signals within one cycle based on the rotor angle signal. By obtaining the parameters of the expressions in equations (1) and (2) through sine and fitting, it can calculate all component information of the magnetic field and gravity vector in the measurement coordinate system:

[0045]

[0046] The vector information obtained by equations (4) and (5) can be used to calculate the measured attitude information using the dual-vector attitude determination algorithm.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A rotating motion-based geomagnetic-gravitational dual vector wireless attitude measurement device, characterized in that, The application relates to a sensor platform rotor (4) rotatably arranged on a base (1), a sensor PCB (5) arranged on the sensor platform rotor (4), a single-axis accelerometer and a magnetometer arranged on the sensor PCB (5), the sensitive axes of the single-axis accelerometer and the magnetometer being coplanar and non-orthogonal to the rotation axis of the sensor platform rotor (4), a power mechanism for driving the rotation of the sensor platform rotor (4), and a rotor angle sensor (10) for detecting the rotation angle of the sensor platform rotor (4). The application further comprises an electric slip ring (9), the rotor of the electric slip ring (9) being connected with the sensor platform rotor (4), and the stator of the electric slip ring (9) being connected with the base (1) of the measuring device. The power mechanism comprises a motor (6), synchronous pulleys (7) arranged on the output shaft of the motor and one end of the sensor platform rotor (4), and a synchronous belt (8) connecting the two synchronous pulleys (7). The application further comprises a controller, the rotor of the electric slip ring (9) being connected with the sensor PCB (5) through a signal line, and the stator of the electric slip ring (9), the motor (6) and the rotor angle sensor (10) being connected with the controller through wires.

2. The dual vector geomagnetic-gravitational wireless attitude sensing device of claim 1, wherein, The application further comprises a rotor support (2) arranged on the base (1), the sensor platform rotor (4) being connected with the rotor support (2) through a bearing, and the rotor angle sensor (10) being arranged on the rotor support (2) on one side.

3. The dual vector geomagnetic-gravitational wireless attitude sensing device of claim 2, wherein, A motor shield shell (3) is arranged outside the motor (6).

4. The dual geodetic gravity vector wireless attitude measurement device of claim 3, wherein, The controller is provided with a WiFi module.

5. A method for attitude measurement by the geomagnetic-gravitational dual vector wireless attitude measurement device according to any one of claims 1 to 4, characterized in that, The application comprises the following steps: The controller receives the magnetometer signal, the accelerometer signal and the rotor angle signal, calculates the component information of the geomagnetic vector and the gravity vector in the measuring coordinate system according to the signals, and describes the magnetometer measuring signal and the accelerometer measuring signal as sine signals, wherein the zero rotation angle position of the sensor platform rotor is taken as the phase zero point of the sine signal, and the rotor angle signal is a period sawtooth pulse signal. Y m = A m sin(ωt+φ m )+B m (1) Y a = A a sin(ωt+φ a )+B a (2) where Y m , Y a are the magnetic field and acceleration values measured by the sensors, respectively, A m , A a are the amplitudes of the magnetometer and accelerometer sinusoidal signals, respectively, ω is the angular velocity of the rotation of the sensor, φ m , φ a are the phases of the two sinusoidal signals, and B m , B a are the direct current components of the two sinusoidal signals, respectively. In the formula, k is a proportional coefficient, and Theta is the rotor rotation angle. Y d = kΘ (3) When the controller receives the sampling signal of the sensor, the rotor angle signal is used to obtain the magnetic field and the accelerometer sine signal in a period, the expression parameters in the formula (1) and the formula (2) are obtained through sine fitting, and the whole component information of the magnetic field and the gravity vector in the measuring coordinate system can be calculated: The vector information calculated through the formula (4) and the formula (5) is used to calculate the measured attitude information through a double vector attitude calculation algorithm. ​

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