KR101564020B1 - A method for attitude reference system of moving unit and an apparatus using the same - Google Patents

Abstract

An acceleration sensor for measuring the acceleration in the X-axis, Y-axis, and Z-axis directions of a moving object, an X-axis gyro sensor for measuring an angular velocity in the X-axis direction of the moving object, Axis gyro sensor and a Y-axis gyro sensor which is different from the X-axis gyro sensor and measures the angular velocity in the Z-axis direction of the moving object and measures the Z-axis gyro sensor of the same kind as the Y-axis gyro sensor, The pitch angle and the yaw angle based on the measured values of the traveling surface of the moving object, the Y-axis gyro sensor and the Z-axis gyro sensor, and the calculation unit calculates the pitch angle and the yaw angle To predict an electronic tax of a moving object.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic three-

The present invention relates to a method for predicting the electronic tax of a moving object and an electronic tax predicting apparatus using the same.

An attitude heading reference system (AHRS) is an apparatus that measures the attitude of a moving object such as a robot, a vehicle, or an aircraft using an inertial sensor. Most AHRSs use an accelerometer, a gyro, and a magnetometer to calculate the posture. The gyro is a sensor that measures the angular velocity of the fuselage. The accelerometer is a sensor that measures the acceleration of the fuselage. The earth magnetic field is a sensor that measures the magnetic field of the earth. Independent posture calculation is possible with only one AHRS Do. In the conventional inertial sensor, the posture is calculated by integrating the angular velocity using a gyro to calculate the roll angle, pitch angle, and yaw angle. However, if the posture calculations are performed, the errors existing in the gyro output accumulate through the integration, resulting in the divergence of the posture error. In this case, the roll angle and the pitch angle can be compensated to some extent by the Kalman filter using the accelerometer sensor output, but since the yaw angle can not be calculated by the accelerometer, it is calculated using only the gyro, It always diverges. Thus, when the yaw angle is critical, the geomagnetic sensor detects the magnetic north and compensates the gyro cal- culation. However, in case of a mobile body running on the surface of iron like a surface of a ship, the earth sensor which detects the magnetic force due to the hull material contains many errors. Therefore, there arises a problem that the yaw angle of the moving object can not be accurately expressed.

It is an object of the present invention to provide a method for calculating a more accurate angle than when the geomagnetic sensor includes many errors due to the surrounding environment.

Another object of the present invention is to provide a method for correcting pitch angle and yaw angle when traveling on the side and bottom of a ship surface to more accurately predict the electronic tax of a moving vehicle traveling on the surface of a ship.

According to an aspect of the present invention, there is provided an apparatus for predicting an electronic aging of a moving object, comprising: an acceleration sensor for measuring accelerations in the X axis, Y axis, and Z axis directions of the moving object; An X-axis gyro sensor for measuring an angular velocity in the X-axis direction of the moving body; A Y-axis gyro sensor which measures an angular speed in the Y-axis direction of the moving body and is different from the X-axis gyro sensor; A Z-axis gyro sensor of the same kind as the Y-axis gyro sensor measuring an angular velocity in the Z-axis direction of the moving body; A calculating unit calculating a roll angle, a pitch angle and a yaw angle of the moving object based on the acceleration measurement result and the angular velocity measurement result of the moving object; Wherein the calculation unit corrects the pitch angle and the yaw angle based on the traveling surface of the moving object and the measured values of the Y-axis gyro sensor and the Z-axis gyro sensor to estimate the electronic tax of the moving object Prediction device.

The Y-axis gyro sensor and the Z-axis gyro sensor may be an optical fiber gyro.

Also, the calculation unit may be an electronic three-wheel prediction device that compensates the calculated roll angle, pitch angle, and yaw angle based on the latitude at which the moving object is located, the rotational angular velocity of the earth, and the attitude of the sensor.

If the traveling surface of the moving body is the side of the hull, it may be an electronic tax prediction apparatus that corrects the pitch angle and the yaw angle using the measured value of the Z axis gyro sensor.

Also, when the traveling surface of the moving body is the undersurface of the hull, it may be an electronic tax prediction apparatus for correcting the pitch angle and the yaw angle using measured values of the Y-axis gyro sensor.

According to another aspect of the present invention, there is provided a method for predicting an electronic aging of a moving object, comprising the steps of: measuring acceleration and angular velocity applied to the moving object using a three-axis acceleration sensor and a three-axis gyro sensor; Calculating a roll angle, a pitch angle and a yaw angle of the mobile object based on the measured acceleration information and the angular velocity information; Determining a position of the moving object based on the roll angle and correcting the pitch angle and the yaw angle using the position of the moving object and the measured values of the three-axis gyro sensor; Lt; RTI ID = 0.0 > a < / RTI >

In addition, the Y-axis gyro sensor and the Z-axis gyro sensor of the gyro sensor may be an electronic tax prediction method which is an optical fiber gyro sensor.

Compensating for the calculated roll angle, pitch angle and yaw angle based on the latitude at which the moving body is located, the rotational angular velocity of the earth, and the attitude of the sensor; Lt; RTI ID = 0.0 > a < / RTI >

In addition, the step of correcting may further include, when the roll angle is 90 degrees, 180 degrees, or 270 degrees,

Correcting the pitch angle and the yaw angle using measured values of the Y-axis gyro sensor and the Z-axis gyro sensor; Lt; RTI ID = 0.0 > a < / RTI >

According to an aspect of the present invention, more accurate angles can be calculated than when the geomagnetic sensor includes many errors due to the surrounding environment.

According to another aspect of the present invention, it is possible to predict the electronic tax of a moving object more accurately by correcting the pitch angle and the yaw angle when the moving body traveling on the ship surface travels on the side and bottom of the ship.

1 is a view for explaining a roll angle, a pitch angle and a yaw angle for expressing the electronic tax of a moving body.
2 is a view showing an error between a yaw angle measured by a conventional sensor and an actual posture.
3 shows an optical fiber gyro used in an embodiment of the present invention.
4 illustrates an example of an electronic tax prediction apparatus according to an embodiment of the present invention.
5 is a graph comparing an actual compensation value with an actual compensation value according to an embodiment of the present invention.
6 is a diagram illustrating a traveling path of a moving object according to an exemplary embodiment of the present invention.

Other advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

Unless defined otherwise, all terms (including technical or scientific terms) used herein have the same meaning as commonly accepted by the generic art in the prior art to which this invention belongs. Terms defined by generic dictionaries may be interpreted to have the same meaning as in the related art and / or in the text of this application, and may be conceptualized or overly formalized, even if not expressly defined herein I will not.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. As used herein, the terms' comprise 'and / or various forms of use of the verb include, for example,' including, '' including, '' including, '' including, Steps, operations, and / or elements do not preclude the presence or addition of one or more other compositions, components, components, steps, operations, and / or components.

The term 'and / or' as used herein refers to each of the listed configurations or various combinations thereof.

It should be noted that the terms such as 'to', 'to', 'to block', and 'to module' used in the entire specification may denote a unit for processing at least one function or operation. For example, a hardware component, such as a software, FPGA, or ASIC. However, '~ part', '~ period', '~ block', '~ module' are not meant to be limited to software or hardware. Modules may be configured to be addressable storage media and may be configured to play one or more processors. ≪ RTI ID = 0.0 > Thus, by way of example, the terms 'to', 'to', 'to block', 'to module' may refer to components such as software components, object oriented software components, class components and task components Microcode, circuitry, data, databases, data structures, tables, arrays, and the like, as well as components, Variables. The functions provided in the components and in the sections ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ' , '~', '~', '~', '~', And '~' modules with additional components.

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a method and a device for predicting an electronic tax of a moving object using an inertial sensor and a high-precision optical fiber gyro. In this specification, the moving body may be a robot, and in particular, may be a cleaning robot for cleaning the surface of a ship while traveling on the surface of the vessel. In addition, although the electronic tax prediction method according to an embodiment of the present invention is described for predicting the electronic tax of a robot traveling on the surface of a ship, it can be applied to an environment in which the environment of the robot causes errors There will be. Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

), Y축을 기준으로 회전한 정도를 피치(pitch,

), Z축을 기준으로 회전한 정도를 요(yaw,

)로 표현한다. 오일러각을 이용하는 방법은 동체 좌표계에서 표현한 고정 좌표계와 동체 좌표계 사이의 회전 각속도와 오일러각의 미분치 사이의 관계를 이용하여 좌표 변환에 필요한 롤, 피치, 요를 계산하고, 이들 세 각을 이용하여 좌표변환 행렬을 구성한다. 이에 대해서는 후에 상세히 서술할 것이다.
1 shows the Euler angles used to express the electronic tax of a moving object. The degree of rotation based on the X axis of the fixed coordinate system is defined as roll (roll,

), The degree of rotation about the Y axis is referred to as pitch (pitch,

), The degree of rotation about the Z axis is required (yaw,

). Euler angles are calculated by calculating the roll, pitch, and yaw required for coordinate transformation using the relationship between the rotational angular velocity between the fixed coordinate system and the body coordinate system expressed in the body coordinate system and the derivative of the Euler angles, Thereby constructing a coordinate transformation matrix. This will be described in detail later.

Fig. 2 shows the results of measurement using an inertial measurement unit (IMU), which is generally used. As described above, the error due to the integral constant is accumulated through the process of estimating the position by integrating the angular velocity, and the posture error is diverted. In FIG. 2, it can be seen that the measurement value diverges due to the error due to integration. In addition, the geomagnetic sensor for compensating the yaw angle can not accurately predict the electronic tax if it contains a lot of errors depending on the surrounding environment.

, 빛의 속도를

라고 하면, 간섭무늬의 이동량

는

가 된다. 따라서, 간섭무늬 이동량

를 측정하면 물체의 각속도

를 구할 수 있고, 광로가 코일 모양으로 감긴 광섬유로 구성되어 있기 때문에

을 크게 할 수 있어서 고정밀, 고감도의 각속도 측정을 할 수 있다.
FIG. 3 shows a fiber optic gyro (FOG) used in an embodiment of the present invention. The principle is that the gyro is a gyro composed of an optical fiber using an optical phenomenon known as the Sagnac effect, which interferes with two beams traveling in a single mode optical fiber. The radius of the coil is R, the length of the single mode optical fiber is L, the wavelength of light in the medium is

, The speed of light

, The movement amount of the interference fringe

The

. Therefore, the interference fringe movement amount

The angular velocity of the object

And since the optical path is composed of an optical fiber wound in a coil shape

It is possible to measure the angular velocity with high precision and high sensitivity.

FIG. 4 shows an apparatus 100 for predicting an electronic watermark according to an embodiment of the present invention. Axis sensors 130, 150 and 170 for measuring three-axis angular velocities of X-axis, Y-axis and Z-axis, and accelerometer sensors 120, 140 and 160 for measuring three axis acceleration of X-, Y- and Z- . Here, the gyroses 150 and 170 for measuring the angular velocity of the Y-axis and the Z-axis may be an optical fiber gyro. Then, the calculation unit 180 can perform the calculation necessary for the electronic tax prediction using the acceleration sensor and the gyro measurement result. In addition, the electronic tax prediction apparatus according to an embodiment of the present invention may include a geomagnetic sensor (not shown).

, Y축으로

, Z축으로

만큼 회전했을 때의 회전 행렬을 나타낸 것이고, 수학식 2는 X축->Y축->Z축 순으로 회전 했을 때 고정 좌표계에서 동체 좌표계로의 변환 행렬을 나타낸 것이다. 수학식 2의 현재 회전 행렬과 수학식 3의 각속도의 변화율의 회전행렬을 구하여 곱하여(수학식4) 적분하는 방법으로 요각을 추출할 수 있다. 이 때 사용되는 Y축 및 Z축의 각속도는 광 섬유 자이로들(150, 170)에서 보다 정확하게 측정된 각속도를 사용하며, X축의 각속도는 롤 각의 변화로 계산한다. 이렇게 되면 보다 정밀한 각속도 측정값을 사용하기 때문에 요 각에 대한 출력이 보다 정밀해 진다.
First, the calculation unit 180 calculates the roll angle, the pitch angle, and the three-axis acceleration information and the three-axis angular velocity information, using the Kalman filter. The roll angle and the pitch angle calculated by the Kalman filter do not cause cumulative error and exhibit an error range of -2 to 2 degrees in a dynamic environment depending on the performance of the sensor. Next, we explain how to calculate the angle. Methods for extracting the yaw angle include a method using a matrix that converts angular velocity to Euler angle in dynamics, an integration method using quaternion, and an integration method using rotation matrix. In the electronic tax prediction method according to an embodiment of the present invention, the yaw angles are extracted using the following Equations 1 to 5 below. Equation (1) can be expressed as

, On the Y axis

, In the Z-axis

And equation (2) shows a transformation matrix from the fixed coordinate system to the body coordinate system when rotated in the order of X, Y, and Z axes. The yaw angle can be extracted by obtaining the rotation matrix of the rate of change of the angular velocity of Equation (3) and multiplying the current rotation matrix of Equation (2) by Equation (4). The Y-axis and Z-axis angular velocities used at this time use angular velocities more accurately measured by the optical fiber gyroses 150 and 170, and the angular velocity of the X-axis is calculated by the change of the roll angle. This results in a more precise angular velocity measurement, resulting in a more accurate output for the yaw angle.

The error of the bias, the sensor attitude, and the integration error are included in the electronic three-leg prediction apparatus according to the embodiment of the present invention. Therefore, it is necessary to compensate for the above error. The sensor includes the earth rotation angular velocity which occurs at the current latitude, and its value changes according to the attitude of the sensor. Equations (6) and (7) below calculate the drift amount according to the sensor attitude measured according to the latitude.

FIG. 5 shows the amount of actual sensor drift measured and the amount calculated using the above equation. As shown in FIG. 6, since the drift amount of the actual sensor is very similar to the theoretical calculated value, the error can be compensated by using the same.

FIG. 6 illustrates an example of a ship cleaning robot including an electronic tax prediction apparatus according to an embodiment of the present invention. In the case of a ship cleaning robot, the entire surface of the ship travels, but it is attached to the side and bottom of the ship and travels. The bow and stern parts of the ship have somewhat curvature, but most of the side and bottom parts have vertical and horizontal planes, and run as shown in Fig. 6 (a) and (b). (a) is a side view, and (b) shows a bottom view. The roll angle of the robot is 90 degrees, 180 degrees, 270 degrees or the like at the side portion and the bottom portion, so that the relationship between the measured value of the electronic aged prediction apparatus according to an embodiment of the present invention and the Euler angular- The error to be diverged can be corrected.

When the robot is located at the side of the ship, the roll angle is 90 degrees or 270 degrees, so that the Z axis gyroscope measures the angular velocity of the Y axis when it is based on the fixed coordinate system. Therefore, the pitch angle can be corrected using the measured value of the Z-axis gyro.

Also, since the roll angle is 0 degrees or 180 degrees at the bottom of the hull, the Y-axis gyro measures the Y-axis angular velocity with reference to the fixed coordinate system. Therefore, the pitch angle can be corrected by using the measured value of the Y-axis gyro.

Calibrations using this method can extract better angles. The following equation indicates that the attitude angle is corrected using the above-described method.

It is to be understood that the above-described embodiments are provided to facilitate understanding of the present invention, and do not limit the scope of the present invention, and it is to be understood that various modifications may be made within the scope of the present invention. For example, each component shown in the embodiment of the present invention may be distributed and implemented, and conversely, a plurality of distributed components may be combined. Therefore, the technical protection scope of the present invention should be determined by the technical idea of the claims, and the technical protection scope of the present invention is not limited to the literary description of the claims, The invention of a category.

100: Electronic tax prediction device
120, 140, 160: acceleration sensor
130, 150, 170: Gyro
180:

Claims (9)

An electronic tax prediction apparatus for a moving object,
An acceleration sensor for measuring acceleration in the X-axis, Y-axis, and Z-axis directions of the moving object;
A gyro sensor for measuring an angular velocity in the X-axis, Y-axis, and Z-axis directions of the moving body; And
A calculating unit calculating a roll angle, a pitch angle and a yaw angle of the moving object based on the acceleration measurement result and the angular velocity measurement result of the moving object;
Lt; / RTI >
The calculation unit predicts the electronic tax of the moving object by correcting the pitch angle and the yaw angle based on at least one of the running surface of the moving object and the measured values of the Y-axis gyro sensor or the Z-axis gyro sensor,
Wherein the Y-axis gyro sensor and the Z-axis gyro sensor are optical fiber gyros,
Axis gyro sensor is corrected using the pitch angle of the moving object when the roll angle of the moving object is 0 degrees or 180 degrees,
Axis gyro sensor is corrected using the pitch angle of the moving object when the roll angle of the moving object is 90 degrees or 270 degrees,
Axis gyro sensor and the Z-axis gyro sensor, and calculates the yaw angle using the corrected measured values of the Y-axis gyro sensor and the Z-axis gyro sensor.
delete The method according to claim 1,
The calculation unit
A pitch angle, and a yaw angle based on a latitude at which the moving body is located, a rotation rate of the rotation of the earth, and a posture of the sensor.
delete delete A method for predicting an electronic tax of a moving object,
Measuring acceleration and angular velocity applied to the moving body using a three-axis acceleration sensor and a three-axis gyro sensor;
Calculating a roll angle, a pitch angle and a yaw angle of the mobile object based on the measured acceleration information and the angular velocity information; And
Correcting the pitch angle and the yaw angle by determining the position of the moving body based on the roll angle and correcting the position of the moving body and the measured values of the Y-axis gyro sensor and the Z-axis gyro sensor of the tri- ;
Lt; / RTI >
The step of correcting
And correcting the yaw angle by correcting the measured values of the Y-axis gyro sensor and the Z-axis gyro sensor constituted by the optical fiber gyro sensor of the 3-axis gyro sensor,
The step of calibrating the angle
Axis gyro sensor is corrected using the pitch angle of the moving object when the roll angle of the moving object is 0 or 180 degrees and the pitch of the moving object when the roll angle of the moving object is 90 degrees or 270 degrees, Correcting the measured value of the Z-axis gyro sensor using the angle; And
And calculating the yaw angle using the corrected measured values of the Y-axis gyro sensor and the Z-axis gyro sensor.
The method according to claim 6,
The step of calculating the angle
The moving body is moved along the X axis

, On the Y axis

, In the Z-axis

And calculating a yaw angle by multiplying the rotation matrix by the rotation matrix of the rate of change of the angular velocity and integrating the rotation matrix when the rotation matrix is rotated in the x-axis, y-axis and z-axis.
The method according to claim 6,
Compensating the calculated roll angle, pitch angle and yaw angle based on the latitude at which the moving body is located, the rotational angular velocity of the earth, and the attitude of the sensor;
Further comprising the steps of:
delete

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