KR20030015650A - Pitch/Roll angle sensing mean using accelerometer and method thereof - Google Patents

Abstract

PURPOSE: An apparatus for measuring a pitch angle and a roll angle using an accelerometer and a method thereof are provided to reduce the size and the power consumption of the apparatus by using a semiconductor chip type acceleration sensing element. CONSTITUTION: An apparatus(100) for measuring a pitch angle and a roll angle using an accelerometer includes an acceleration sensing part(110) sensing acceleration by movement, a memory part(120) storing errors of data measured by the acceleration sensing part(110), a control part(130) compensating errors by using the data measured at the acceleration sensing part(110) and error data stored at the memory part(120) and calculating a pitch angle and a roll angle, a display part(140) displaying the error-compensated pitch angle and roll angle, and a communication part(150) transmitting the error-compensated pitch angle and roll angle to the other device or equipment.

Description

Pitch / Roll angle sensing mean using accelerometer and method

The present invention relates to a measuring device for measuring the angle in the horizontal to vertical state of an object or device located in a three-dimensional space, and more particularly by using an acceleration sensing means in the form of a compact and low power semiconductor chip The present invention relates to a pitch angle / roll angle measuring device using an acceleration sensing means that can be mounted on various machinery, electronic devices, etc., and can also be used as a portable device.

In general, the device and the device should be made in the correct horizontal state for operation, even if the ground is flat, it is not easy to establish the exact horizontal state due to the overall slope.

That is, for example, in the case of a washing machine or a refrigerator, such as home appliances, the washing machine is a washing machine, the load of the laundry including water by the drive of the motor is applied to the ground and all sides, if the correct level is not made, Since the motor of the washing machine is affected by the rotation of the washing machine, a lot of load is applied, and the rotation of the washing tank is also affected, which may damage the washing tank. In addition, even in the case of the refrigerator is not the exact horizontal state, when the flow of the refrigerant by the drive motor is affected by the flow of the refrigerant is not smooth, there is a problem that the refrigeration efficiency is lowered and the power consumption of the refrigerator is increased. In addition, in the case of a large load of equipment, if the horizontal state is unstable, it may adversely affect the fixed state when the equipment is operated, thereby increasing the vibration and noise, as well as shortening the durability.

In addition, in the construction site, the necessity to accurately set the vertical reference line and the horizontal reference line occurs, such as building blocks vertically or horizontally to install the wood. Thus, in order to set the horizontal reference line and the vertical reference line in a very primitive way or to maintain the level at the time of installation of the device and the device, the height of the support for supporting the device and the device was adjusted to establish the level of the device and the device.

In addition, various kinds of conventional techniques for measuring a pitch angle / roll angle during installation or management of various machinery, electronic products, civil engineering, and building construction are known. That is, the device for measuring the pitch angle / roll angle to visually check the movement of water droplets or bubbles in accordance with the change of the inclination angle (Korean Utility Model Publication No. 87-001067, 88-001138, 90-007093, 95- 031155, 96-005899), Apparatus for visually or electronically inspecting the movement of weight due to gravity through a goniometer, ruler or indicator needle (Korean Utility Model Publication No. 85-002826, 86-008314, 89-007366, 98-063558), Apparatus or method for measuring the inclination of inclination angle using a laser and a reflector (Korean Patent Publication Nos. 96-001738, 00-037230, Utility Model Registration No. 122508 , No. 178908, No. 199303), Method of inspecting the liquid having electrical conductivity and its inclination according to the inclination angle through the electrode sensing unit (Korean Patent Registration No. 157106), Current induced in the iron core according to the iron core and the inclination angle To measure changes in Patent Publication No. 90-017504), using a pressure sensor and an acceleration sensor (Korean Patent Registration No. 159627), or using an acceleration sensor, an inclination sensor, a geomagnetic sensor (Korean Patent Registration No. 164659) to determine the inclination angle of a moving object. Measuring method;

The conventional method as described above has a problem that it is difficult to accurately measure when visually measuring, and it is difficult to miniaturize the measuring apparatus because a bulky sensor such as a laser or a pressure sensor is used, and the measured value of the pitch angle / roll angle is obtained. There was a problem that it is difficult to configure the horizontal or vertical holding device by connecting to the device.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to be equipped with various types of machinery, electronic devices, etc. as well as portable by using an acceleration sensing means in the form of a miniaturized and low power semiconductor chip. It is to provide a pitch angle / roll angle measuring device using the acceleration detection means that can be used.

Another object of the present invention is to provide a measuring method for measuring an accurate pitch angle / roll angle by using an acceleration sensing means in the form of a semiconductor chip, by compensating for an error generated.

1 is a schematic block diagram illustrating a pitch angle / roll angle measuring device using an acceleration sensing means according to the present invention;

2 is a schematic configuration diagram of an acceleration sensing unit according to the present invention.

3 is an explanatory diagram for explaining the principle of inclination angle measurement for explaining the present invention,

4 is an explanatory diagram for explaining a process of calculating a pitch angle / roll angle using an acceleration sensing means in a three-dimensional space for explaining the present invention;

5 is an explanatory diagram for explaining an experiment for bias compensation of the acceleration sensing means according to the present invention,

6 is an explanatory diagram for explaining a process of calculating by inputting + G for the compensation of the acceleration detection means conversion coefficient error according to the present invention;

7 is an explanatory diagram for explaining a process of calculating by inputting -G for the compensation of the acceleration detection means conversion coefficient error according to the present invention;

8 is a graph showing the experimental results of the bias error estimation according to the present invention,

9 is a graph showing the experimental results of the conversion coefficient error estimation according to the present invention,

10 is a graph showing a result of the normal error compensation according to the present invention;

11 is a graph showing the correlation function of the irregular error of the acceleration detection means according to the present invention,

12 is a graph showing the frequency characteristics of the irregular error of the acceleration sensing means according to the present invention,

FIG. 13 is an explanatory diagram for explaining an estimation of a square angle through acceleration detection means irregular error compensation according to the present invention; FIG.

14 is a graph showing an irregular error compensation result of the acceleration detecting means according to the present invention;

15 is a flowchart illustrating a pitch angle / roll angle measuring method using an acceleration sensing means according to the present invention.

Explanation of symbols on the main parts of the drawings

100: pitch angle / roll angle measuring device 110: acceleration detection unit

111: first acceleration detection means 112: second acceleration detection means

115: A / D converter 116: acceleration detection means

117: low pass filter 120: memory

130: control unit 131: regular error compensation unit

132: irregular error compensation unit 133: pitch angle / roll angle calculation unit

140: display unit 150: communication unit

In order to achieve the above object, the present invention is a measuring device for measuring the angle of the range from the horizontal to vertical state of the object or device located in the three-dimensional space, the acceleration detection unit for detecting the acceleration by the movement and And a memory unit for storing the error of the data measured by the acceleration sensing unit, a control unit for compensating the error using the data measured by the acceleration sensing unit and the error data stored in the memory unit, and calculating a pitch angle / roll angle. And a display unit for displaying a pitch angle / roll angle in which an error is compensated under the control of the controller, and a communication unit for transmitting the pitch angle / roll angle in which the error is compensated under the control of the controller to another device or device. Characterized in that configured.

The acceleration detection unit is characterized in that the acceleration detection means of the semiconductor chip form installed on at least two on the three-dimensional axis.

In addition, in the method for calculating the pitch angle / roll angle of the device in a three-dimensional space, the first step of detecting the acceleration force by the movement by the acceleration sensing means as the acceleration force for the plurality of axes, and in the first step Compensating the normal error of the accelerometer sensing means used in the second step of calculating the plurality of axial components with respect to gravity by using the acceleration force for the plurality of axes sensed by the acceleration sensing means. And a roll angle using the axial component of the accelerometer in which the irregular error is compensated in the second and fourth steps, and the fourth step of compensating the irregular error in the acceleration detecting means for which the normal error is compensated in the third step. And a sixth step of calculating a pitch angle using the axial component and the roll angle calculated in the second and fifth steps.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. In addition, this embodiment does not limit the scope of the present invention, but is presented by way of example only.

1 is a schematic block diagram for explaining a pitch angle / roll angle measuring device using an acceleration sensing means according to the present invention.

As shown, the pitch angle / roll angle measuring device 100 using the acceleration detection means according to the present invention and the acceleration detection unit 110 for detecting the acceleration by the movement of the device, and the acceleration detection unit 110 measured Compensation for the error by using the memory unit 120 for storing the error of the data, the data measured by the acceleration detection unit 110 and the error data stored in the memory unit 120 and calculates the pitch angle / roll angle The controller 130 to display the pitch angle / roll angle calculated by the controller 130 and the communicator 150 transmitting the pitch angle / roll angle calculated by the controller 130 to another device or device. It consists of.

As shown in FIG. 2, the acceleration detecting unit 110 includes a first acceleration detecting unit 111 and a second acceleration detecting unit 112, wherein two of three three-dimensional axes X, Y, and Z are included. It is placed on one axis so that it is positioned at right angles on one plane.

In the present embodiment, the first acceleration detecting means 111 is disposed on the X axis, and the second acceleration detecting means 112 is disposed on the Y axis.

In addition, the first and second acceleration detecting means 111 and 112 may be formed in the form of a semiconductor chip to reduce the size of the measuring device of the present invention and to be mounted on a predetermined portion of a device to be installed.

Therefore, in the acceleration detecting unit 110 of the present embodiment, the first acceleration detecting unit 111 detects the acceleration in the X-axis direction, and the second acceleration detecting unit 112 detects the acceleration in the Y-axis direction.

The detected acceleration force values in the axial direction are input to the control unit 130. In this case, the signals are A / D converted through the A / D conversion unit 115 and input to the control unit 130 as shown in FIG. 1. do.

The control unit 130 compensates for the acceleration force input by using the normal error of the x-axis acceleration detecting means 111 and the y-axis acceleration detecting means 111 stored in the memory unit 120. ), A non-normal error compensator 132 for compensating an irregular error in the signal of the acceleration force compensated by the normal error compensator 131, and an acceleration signal value at which the irregular error is compensated by the irregular error compensator 133. It comprises a pitch angle / roll angle calculation unit 133 for calculating the pitch angle / roll angle of the device using.

The irregular error compensator 132 may be configured as a low pass filter for filtering high frequency noise components.

The display device 140 is installed on one side of the pitch angle / roll angle measuring device using the acceleration detecting means of the present invention to visually check the values of the pitch angle and the roll angle calculated by the pitch angle / roll angle calculation unit 133.

In addition, the communication unit 150 transmits the values of the pitch angle and the roll angle calculated by the pitch angle / roll angle calculation unit 133 to an external device so as to use the calculated values of the pitch angle and the roll angle.

The pitch angle / roll angle measuring device and the method using the acceleration sensing means according to the present invention configured as described above will be described in more detail with reference to the accompanying drawings.

First, the gravitational acceleration of the earth can be measured by the acceleration sensing means for measuring the acceleration of the object. The gravitational acceleration affects differently depending on the attitude of the accelerometer placed on an object or device. As shown in FIG. 3, when the acceleration sensing means 116 is attached to the inclined surface, the acceleration sensing means detects a gravity acceleration component that matches the sensing direction of the acceleration sensing means.

The output f of the acceleration sensing means is ideal , The angle of inclination of the object ( ) Becomes

When the concept of FIG. 3 is expanded, when the three-dimensional space is represented by using the X, Y, and Z axes, the present invention may, as shown in FIG. 4, include the first acceleration detecting means 111 installed in the x-axis direction in the xy plane. Pitch angle of the xy plane using the second acceleration detecting means 112 installed in the y-axis direction ( ) And roll angle ( ) Can be measured. Pitch angle in three-dimensional space ) And roll angle ( ) Is given by

From here, Is the output of the first acceleration detecting means 111 installed in the X-axis direction, Is the output of the second acceleration sensing means 112 provided in the T-axis direction.

However, since the acceleration sensing means in the form of a semiconductor chip used for miniaturization includes many error factors, the error must be compensated for to obtain an accurate pitch angle / roll angle.

Accordingly, the errors of the first and second acceleration detecting means 111 and 112 are classified into regular errors such as bias errors and conversion coefficient errors caused by manufacturing processes and electrical circuit errors, and irregular errors having random components.

The method for compensating for the normal error includes an explanatory diagram of FIG. 5 for acceleration sensing means bias compensation and a conversion coefficient of acceleration sensing means of FIG. Referring to FIG. 7, which is an explanatory diagram of an experiment in which -1G is input for error compensation, is as follows. 5 to 7, A represents the direction of gravity and B represents the direction of acceleration measurement.

That is, after setting the input / output model of the acceleration sensing means 116, the change is recorded while applying the correct input, and the normal error compensation is performed based on this data. Through this, the conversion coefficient error and the bias error of the acceleration detecting means 116 are compensated. That is, for normal error compensation, the bias is applied to the first and second acceleration sensing means 111 and 112 of the present invention using gravity as the acceleration input of the horizontal plane -G, 0G, G, and then the bias and conversion coefficient error are determined. Calculate the stability of

Here, 1G is a value representing gravity acceleration, that is, 9.8 m / sec ² .

Therefore, when the calculated bias error and the conversion coefficient error are stored in the memory unit 120, the errors of the first and second acceleration detection means 111 and 112 can be compensated for.

8 is a graph showing the experimental results of the bias error estimation, it can be seen that the bias error of the x-axis and y-axis represented as a function of the angle and time can be estimated and compensated.

9 is a graph showing the experimental results of the conversion coefficient error estimation as a function of the acceleration force and the output signal, showing the difference between the conversion coefficient error and the nonlinear error.

Accordingly, the measurement model of the first and second acceleration detecting means 111 and 112 including an error factor for the compensation of the normal error is as follows.

From here, , Are the outputs of the first and second acceleration detecting means 111 and 112 provided on the x and y axes, respectively. , Is the conversion factor, , Is the bias of the first and second acceleration detecting means (111, 112), , Is the measurement noise, , Is the input acceleration.

Ideally, the bias of the first and second acceleration detecting means 111 and 112 should have a value of zero, but in reality, the bias of the first and second acceleration detecting means 111 and 112 will be different from zero due to an error in the manufacturing process, noise by an electric circuit, and the like. Therefore, the correction should be performed through the normal error compensation method.

The ideal conversion factor may be obtained according to the measurement range of the first and second acceleration detection means 111 and 112 and the output range of the first and second acceleration detection means 111 and 112. For example, if the measurement range of the first and second acceleration detecting means 111 and 112 is -G to + G and the output is -2.5 volts to +2.5 volts, then the ideal conversion factor Becomes 2G / 5volts.

However, the error exists due to manufacturing error and electrical noise, so it must be compensated for.

To this end, first, the input acceleration of the horizontal plane 0G is applied to the first and second acceleration detecting means 111 and 112 using gravity to determine the x-axis bias error, and the following method is performed. As shown in FIG. 5, when the first and second acceleration detecting means 111 and 112 are placed at right angles to the center direction of the earth (the direction of the geoid) on the flat plate maintained at the correct horizontality, the input of the horizontal plane 0G is first and second. 2 Acceleration sensing means 111 and 112 The output obtained at this time is a bias error.

To reduce the error of random components, the output is accumulated and averaged to find the bias error. The obtained bias error is stored in the memory unit 120 via the A / D converter 115 and the controller 130.

Next, the x-axis conversion coefficient error is Because of The conversion coefficients of the first and second acceleration detecting means 111 and 112 ideally obtained ) And conversion factor error ( Can be separated.

As shown in FIG. 6 again, when the first and second acceleration detecting means 111 and 112 are placed in a positive vertical direction on a flat plate having an accurate level, the input of the horizontal plane + G is applied to the first and second acceleration sensing. It is applied to the means (111, 112) and stores the output of the first and second acceleration detection means (111, 112) in the memory unit 120.

As shown in FIG. 7, when the first and second acceleration sensing means 111 and 112 are placed in the negative vertical direction, an input of a horizontal plane -G is applied to the first and second acceleration sensing means 111 and 112 and output. Record cumulatively.

Bias in Uses the values obtained in the previous bias estimation process, Uses the conversion factors of the first and second acceleration detection means (111, 112) ideally obtained. f_x is the input acceleration applied to the horizontal plane + G or -G Is the output value of the measured first and second acceleration detection means (111, 112). In order to reduce the error of the random component, the average of the measured values is obtained, and the conversion coefficient error is obtained and stored in the memory unit 120. When the error is compensated in this way, a perfect compensation is achieved as shown in the graph showing the compensation result of the normal error in FIG. 10. Also, if used for the y-axis in the same way as above, ) And conversion factor error ( ) Can be obtained.

Measurement errors of the first and second acceleration detecting means 111 and 112 measured after compensating for the normal error may be classified into irregular errors. FIG. 11 is a graph showing a correlation function of acceleration detecting means irregular errors. As shown in FIG. 12, which is a graph illustrating the frequency characteristics of the acceleration detection means irregular error, the correlation function and the frequency characteristic analysis result of the measurement errors of the first and second acceleration detection means 111 and 112 can be modeled as white noise. The signals of the first and second acceleration detecting means 111 and 112 obtained after compensating the normal error are composed of components (low frequency) caused by the reaction of gravity and components (high frequency) represented by noise. Accordingly, when the inclination angle is obtained by using the first and second acceleration detecting means 111 and 112, the low pass filter 117 as shown in FIG. Use

Therefore, the measured noise (C) and the measured component (D) mixed in the acceleration sensing means are the measured noise (C) which is a high frequency passing through the low pass filter (117) is blocked and the measured value compensated by passing only the measured component (D). Component (E) can be obtained. That is, after passing through the low pass filter 117, the component by the reaction of gravity can be extracted (absolute inclination angle estimation). The result of compensating the irregular error using the low pass filter 117 is shown as a graph of the irregular error compensating result in FIG. 14.

In order to measure the pitch angle / roll angle, the acceleration sensing means are installed at right angles to each other as shown in FIG. 2, and the method for calculating the pitch angle / roll angle after A / D conversion of the measured acceleration values is as follows.

The normal error such as bias and conversion factor error is measured by the controller 130 by reading the value stored in the memory unit 120 and compensating for the error, and measuring the first and second acceleration sensing means 111 and 112 remaining after the normal error compensation. The value is a component of the reaction of irregularity and gravity.

A lowpass digital filter is used to compensate for the irregular error. After passing through the low pass digital filter, the measured values of the first and second acceleration detecting means 111 and 112 remain only as components of acceleration due to the reaction of gravity. , Speaking of the pitch angle / roll angle calculation of the control unit 120 , The pitch angle / roll angle can be measured by.

The measured tilt angle may be displayed numerically by the display apparatus 140 or transmitted to another device through the communication unit 150 to utilize pitch angle / roll angle data.

That is, the first and second acceleration sensing means 111 and 112 in the form of semiconductor chips are used, but the error compensation and the roll angle ( ), Pitch angle ( Attaching the control unit 120 for a calculation can be configured a miniaturized pitch angle / roll angle measuring device.

In addition, since the controller 120 may output the pitch angle / roll angle displayed as a digital value, a horizontal or vertical holding device may be configured through connection with various devices.

Accordingly, when the pitch angle / roll angle is measured by the pitch angle / roll angle measuring device using the acceleration sensing means of the present invention, as shown in FIG. 15 to illustrate the measuring method in a different axial direction among three-dimensional axes A first step 201 for measuring the acceleration of the device with two or more acceleration sensing means respectively installed; and the plurality of gravity-dependent forces using the acceleration force for the respective axes sensed by the acceleration sensing means in the first step. A second step 202 of calculating two axial components, a third step 203 of compensating a normal error of acceleration components for each axis calculated in the first and second steps, and a normal error in the third step A fourth step (204) of compensating an irregular error of the acceleration component compensated for, and a fifth step (205) of calculating the roll angle using the acceleration component of the acceleration sensing means compensated for the irregular error in the second and fourth steps. Wow, said agent The sixth step 206 of calculating the pitch angle using the axial components and the roll angles calculated in steps 2 and 5 is to measure the acceleration and calculate the pitch angle / roll angle.

Therefore, as described above, the present invention can reduce the size of the measuring device by using the acceleration sensing means in the form of a semiconductor chip. There is an advantage that can be used as, the pitch angle and the roll angle is a digital value output from the control unit and transmits to other devices through the communication unit has the advantage that the utilization is high.

In addition, there is an advantage that the pitch angle / roll angle can be accurately measured by compensating the normal and irregular errors through the control unit.

Claims (7)

In order to achieve the above object, the present invention is a measuring device for measuring the angle of the range from the horizontal to vertical state of the object or device located in the three-dimensional space, the acceleration detection unit for detecting the acceleration by the movement and , A memory unit for storing an error of data measured by the acceleration detector; A controller for compensating for the error by using the data measured by the acceleration sensing unit and the error data stored in the memory unit, and calculating a pitch angle / roll angle; A display unit for displaying a pitch angle / roll angle whose error is compensated under the control of the controller; Pitch angle / roll angle measuring device using an acceleration sensing means characterized in that it comprises a communication unit for transmitting to the other device or device the pitch angle / roll angle, the error is compensated under the control of the controller. The apparatus of claim 1, wherein the acceleration sensing unit is in the form of a semiconductor chip, and two or more acceleration sensing units are installed on a three-dimensional axis. The pitch angle using the acceleration sensing means according to claim 2, wherein the acceleration sensing unit comprises first acceleration sensing means and second acceleration sensing means arranged on two axes among three-dimensional axes to form a right angle on one plane. Roll angle measuring device. The apparatus of claim 1, wherein an A / D conversion unit is formed between the acceleration detection unit and the control unit. The method of claim 1, wherein the control unit A normal error compensator for compensating for bias error and conversion factor error, A non-normal error compensator for filtering the high frequency of the noise component, Pitch angle / roll angle measuring device using the acceleration sensing means, characterized in that consisting of a pitch angle / roll angle calculation unit for calculating the pitch angle and the roll angle as a measurement value of the acceleration sensing means compensated for the normal error and the irregular error. 6. The pitch angle / roll angle measuring device using acceleration sensing means according to claim 5, wherein the irregular error compensating part is a low pass filter. In the measuring method for measuring the pitch angle / roll angle, A first step of measuring the acceleration of the device by two or more acceleration sensing means respectively installed in different axial directions of the three-dimensional axis A second step of calculating the plurality of axis components for gravity by using the acceleration force for each axis sensed by the acceleration sensing means in the first step; A third step of compensating the normal error of the acceleration component for each axis calculated in the first and second steps; A fourth step of compensating an irregular error of the acceleration component whose normal error is compensated in the third step; A fifth step of calculating a roll angle using the acceleration component of the acceleration sensing means, in which the irregular error is compensated in the second and fourth steps; And a sixth step of calculating a pitch angle using the axial components and the roll angles calculated in the second and fifth steps.