KR19990075794A - Calculation method of traveling angle using geomagnetic sensor - Google Patents

Abstract

A traveling direction calculating method using a geomagnetism sensor according to the present invention is a method of calculating a traveling direction using a geomagnetism sensor by analog-to-digital conversion of a signal of a geomagnetism sensor mounted on a moving object to calculate an angle within a predetermined angle range according to a ratio of output of the converted signal, And calculating a progress angle of the moving object according to the calculated weight by calculating a weight according to all the angles divided by the plurality of divided points, thereby calculating the traveling direction of the moving object by simplifying the calculation

By using the geomagnetic sensor according to the present invention, the signal of the geomagnetism sensor mounted on the moving object is subjected to analog / digital conversion and the angle is calculated within a predetermined angle range according to the ratio of the output of the converted signal.

By calculating the weights according to all angles divided by a plurality of geomagnetism sensor outputs, we can calculate the moving angle of the moving object with different simple expressions according to the calculated weights, Can be calculated.

Description

Calculation method of traveling angle using geomagnetic sensor

The present invention relates to a method of calculating a traveling angle using a geomagnetism sensor, which comprises analog to digital conversion of a signal of a geomagnetism sensor mounted on a moving object, comparing the output of the converted signal with each other, The present invention relates to a method of calculating a traveling angle using a geomagnetic sensor.

1 is a block diagram of an apparatus for calculating a traveling angle using a conventional geomagnetic sensor.

2 is a control flowchart of a conventional method of calculating a traveling angle using a geomagnetic sensor.

3 is an explanatory view of a geomagnetic sensor.

4 is an output waveform of the geomagnetic sensor.

Referring to FIG. 1, there is shown a geomagnetic sensor 1 for detecting a geomagnetism as the moving object moves, an analog / digital converter 2 for converting the output of the geomagnetic sensor 1 into digital, A read only memory 4 for storing preset data, and a control unit 3 for outputting an output from the analog / digital converter 2 to the control unit 3, A random access memory 5 for storing data input by the user 3, and the like.

The geomagnetic sensor 1 is a device for detecting a geomagnetic field.

The geomagnetic sensor 1 is a ring-shaped high magnetic permeability permalloy, in which excitation coils are wound in the same direction as the entire circumference, and the detection coils X and Y are wound orthogonally to each other in the radial direction of the core have.

When the geomagnetic sensor is rotated in the clockwise direction with the direction of the Y coils of the geomagnetic sensor 1 set to the north-south direction and the direction of the X coils to the east-west direction, a sinusoidal wave is output from the X coils and the Y coils.

At this time, a cosine wave is outputted from the X coil of the geomagnetic sensor 1, and a sine wave is outputted from the Y coil.

The geomagnetic sensor 1 is mounted on a moving vehicle, and detects the moving direction of the vehicle.

The process of detecting the moving direction of the moving object by using the geomagnetic sensor 1 is as follows.

First, the geomagnetic sensor 1 is mounted on a moving body to calculate an initial value (S10). The initial values are the center values of the respective outputs of the geomagnetic sensor 1.

In order to calculate the initial value, the geomagnetic sensor 1 is mounted on the moving body and then rotated one clockwise.

The respective outputs of the geomagnetic sensor 1 are input to the analog-to-digital converter 2 accordingly. The analog-to-digital converter 2 converts the output of the input geomagnetic sensor 1 into a digital signal and outputs it to the control unit 3.

The control unit 3 receives the data output from the analog-to-digital converter 2 as an input and outputs the intermediate value C _X of the output of the X coil and the output of the Y coil while the geomagnetic sensor 1 rotates by one rotation The value (C _Y ) is obtained.

The control unit 3 obtains the maximum value and the minimum value of the output of the X-coil while the geomagnetic sensor 1 rotates by one rotation to obtain an intermediate value, and obtains an average of the two values to set the value as an intermediate value (C _X ). And the median of the control section 3 is a geomagnetic sensor (1) the intermediate value (C _X) and the output of the Y coil of the two values, obtain the maximum value and the minimum value of the output of the Y coil during the wheel rotation (C _Y) . (C _Y ) of the output of the Y coil.

After the initial setting S10 of the geomagnetic sensor 1 is as follows.

When the moving object equipped with the geomagnetic sensor 1 moves, the output of the geomagnetic sensor 1 changes according to the movement of the moving object. The output of the geomagnetic sensor 1 is input to the A / D converter 2. The analog-to-digital converter 2 receives the output of the geomagnetic sensor 1 as an input and converts it into a digital signal.

The control unit 3 receives the output of the analog-to-digital converter 2 as an input to calculate the traveling angle of the vehicle.

The control unit 3 divides the entire 360 degrees into two sections (0 to 180 degrees, 181 to 359 degrees) in order to calculate the traveling angle of the vehicle, and calculates the ratio of the outputs of the detection coils X and Y to the ratio The process of calculating the running angle [theta] of the vehicle by comparing the value with a predetermined table is as follows.

First, the control unit 3 converts the output (X, Y) of the geomagnetic sensor 1 into digital by the analog / digital converter 2 and stores the input (X, Y) in RAM 5 as a memory (S20).

After storing the output of the geomagnetic sensor 1 in the RAM, the control unit 3 obtains X 'and Y' using the intermediate values (C _X , C _Y ) of the output values of the geomagnetic sensor 1 obtained previously (S30). X ' , Y ' .

When the values of X 'and Y' are obtained, the ratio of X 'and Y' is found, and the ratio (Z _m ) is X '/ Y' (S40).

When the ratio Z _m is obtained, the controller 3 compares the obtained ratio Z _{m with} the value of the look-up table stored in advance in the ROM 4 to obtain the traveling direction h 'of the vehicle (S50 ).

A look-up table is _non-(m Z) are a table and a moving direction (h ') set according to the ratio (Z _m) is in the from 0 to 180 degrees divided angle 360 determined according to the open-circuit.

After obtaining the moving direction h 'of the vehicle by using the data of the lookup table, the control unit 3 determines the moving direction of the moving object in order to obtain the final angle (S60).

The control unit 3 determines whether the output Y of the geomagnetic sensor is greater than 0 in order to determine the section of the traveling direction of the vehicle (S60). The output of the Y coil of the geomagnetic sensor is a sine wave. The sine wave has a positive value at 0 to 180 degrees and a negative value at the other angles.

If it is determined in step S60 that the output Y of the geomagnetic sensor is greater than 0, the controller sets the final moving direction h of the moving object to the moving direction h 'in step S70.

If it is determined in step S60 that the output Y of the geomagnetic sensor is smaller than 0, the controller sets the final moving direction h of the moving object to an angle obtained by adding 180 degrees to the moving direction h ' .

After the final traveling angle of the moving object is set, the control unit outputs the data to the navigation device main body so that the navigation device control unit displays the information using the data (S80).

Lookup table Z _m h ' O ° Z ₁ h'1 10 ° : : : Z ₃₆₀ h ' ₃₆₀ 179.5 DEG

However, in the conventional angular calculation method using the geomagnetic sensor 1, minus (-) components appear in the calculation equations (XC _X ) and (YC _Y ), which makes it difficult to implement an equation.

In addition, since the entire angle (360 degrees) is divided into two tables, the table data becomes vast, requiring a lot of memory for storing table data.

SUMMARY OF THE INVENTION In order to solve the above-described problem, the present invention has been made to solve the above-described problem by providing a geomagnetic sensor that converts a signal of a geomagnetism sensor mounted on a moving object into an analog signal, And calculating a progress angle of the moving object according to the weight value calculated by dividing a plurality of divided weights into a plurality of divided weights, thereby calculating the traveling direction of the moving object by simplifying the calculation There is a purpose.

1 is a block diagram of an apparatus for calculating a traveling angle using a conventional geomagnetic sensor.

2 is a control flowchart of a conventional method of calculating a traveling angle using a geomagnetic sensor.

3 is an explanatory view of a geomagnetic sensor.

4 is an output waveform of the geomagnetic sensor.

5 is a block diagram of an apparatus for calculating a traveling angle using a geomagnetic sensor according to the present invention.

6A and 6B are control flowcharts of a method of calculating a traveling angle using a geomagnetic sensor according to the present invention.

FIG. 7 is an explanatory diagram of a weight setting of a traveling angle calculating method using a geomagnetic sensor according to the present invention.

8 is a table of angle calculation formulas according to the weight setting of the traveling angle calculation method using the geomagnetic sensor according to the present invention.

Description of the Related Art [0002]

11: geomagnetic sensor 12: analog / digital converter 13:

14: a lookup table storage unit 15;

According to an aspect of the present invention, there is provided a geomagnetic sensor comprising: a geomagnetic sensor provided in a moving body for sensing a geomagnetic field to output an X signal and a Y signal; an analog / digital converter for converting the output of the geomagnetic sensor to digital; A geomagnetic sensor angle calculation device comprising: a digital conversion step of receiving an output of a geomagnetism sensor and converting the digital signal into a digital signal and outputting the digital signal to a control unit; An output ratio calculation step of calculating a ratio of the output signal of the geomagnetic sensor according to the set weight after the weight is set after the weight setting step; Converts the ratio of the output signal of the geomagnetism sensor to an angle And an absolute angle calculating step of converting the angles converted in the angle converting step into absolute angles by different calculation formulas according to the weights.

Hereinafter, preferred embodiments will be described in detail with reference to the accompanying drawings.

5 is a block diagram of an apparatus for calculating a traveling angle using a geomagnetic sensor according to the present invention.

6A and 6B are control flowcharts of a method of calculating a traveling angle using a geomagnetic sensor according to the present invention.

FIG. 7 is an explanatory diagram of a weight setting of a traveling angle calculating method using a geomagnetic sensor according to the present invention.

8 is a table of angle calculation formulas according to the weight setting of the traveling angle calculation method using the geomagnetic sensor according to the present invention.

5, a geomagnetism sensor 11 for detecting geomagnetism as the moving object moves, an analog / digital converter 12 for converting the output of the geomagnetism sensor 1 into digital, an analog / digital converter 2, A lookup table storing unit 14 storing previously set data, and a control unit 13 for controlling the operation of the control unit 13 from the analog / digital converter 12, And a memory unit 15 for storing data input by the user.

The geomagnetic sensor according to the present invention will now be described.

First, the geomagnetism sensor 11 is a ring-shaped high permeability permalloy, and an excitation coil (not shown) is wound in the same direction as the entire circumference direction, and the detection coils X, Y Are wound orthogonally to each other in the radial direction of the core.

The geomagnetic sensor 11 is excited by an alternating current flowing in an excitation coil (not shown) to form magnetic force lines inside the ring-shaped core. The lines of magnetic force are formed only inside the core and the core is ring-shaped, so no stimulation is formed.

However, when a magnetic field is applied from the outside in a direction parallel to the Y coil, a maximum voltage is generated in the X coil. When a magnetic field is applied from the outside in a direction parallel to the coil, the coil voltage is induced.

The geomagnetic sensor 11 is installed at the center of the ceiling of the vehicle which is not easily affected by the magnetic field from the electric parts of the vehicle. The geomagnetic sensor 11 outputs a voltage to the X-coil and the Y-coil in accordance with the motion of the vehicle.

Meanwhile, in the progress angle calculating method using the geomagnetism sensor according to the present invention, the total angle (360 degrees) is divided into 8 equal parts, and the weight is divided by 45 degrees (FIG. 7). The weighting is made up of 3 bits (B ₂ B ₁ B ₀ ) binary. Each bit of the weight has its own meaning and its meaning will be explained below.

The operation is as follows.

The output of the geomagnetic sensor 11 is input to the A / D converter 2. The analog-to-digital converter 12 outputs a value ADY obtained by converting the output X of the geomagnetism sensor 11 into a digital value and a value ADY obtained by digitally converting the output Y of the geomagnetic sensor 11 to the control unit 13.

The control unit 13 stores the outputs ADX and ADY of the analog-to-digital converter 12 in the memory unit 15 (S100).

The control unit 13 stores ADX and ADY in the memory unit 15 and then calculates maximum, minimum, and intermediate values for the values (S110).

The control unit 13 calculates a value obtained by subtracting the X intermediate value from the ADX (S120) and determines whether the calculated value is greater than zero (S130).

If determined that the value obtained by subtracting the value X from the intermediate ADX in the determination (S130) greater than zero control unit 13 sets the weight B ₁ by 1 (S131). However, if it is determined the value obtained by subtracting the value X from the intermediate ADX in the determination (S130) is larger than zero control unit 13 sets the weight B ₁ to 0 (S140).

The meaning of the weight B ₁ is as follows.

If the weight B ₁ is 1, the vehicle will proceed westward with the north-south center line. On the other hand, if the weight B ₁ is 0, the vehicle travels to the north-south center line in the east direction.

After setting the weight B ₁ , the controller 13 determines whether the value obtained by subtracting the Y intermediate value from ADY is greater than zero (S150).

If determined that the value obtained by subtracting the value Y from the intermediate ADY the determination (S150) greater than zero control unit 13 sets the weight B ₂ to 1 (S151). However, if it is determined the value obtained by subtracting the value Y from the intermediate ADY the determination (S150) is larger than zero control unit 13 sets the weight B ₂ as 0 (S160).

The meaning of the weight B ₂ is as follows.

If the weight B ₂ is 1, the vehicle will proceed to the south with the east-west center line. On the other hand, if the weight B ₂ is 0, the vehicle will proceed to the north from the east-west center line.

After setting the weight B ₂ , the control unit 13 determines whether the value obtained by subtracting ADY from ADX is greater than zero (S170).

If determined that the value obtained by subtracting the ADY from ADX in the determination (S170) greater than zero control unit 13 sets the weight B ₀ to 1 (S171). Then, the control unit 13 obtains a value Z obtained by dividing ADX by ADY (S172).

However, if it is determined the value obtained by subtracting the ADY from ADX in the determination (S170) is larger than zero control unit 13 sets the weight B ₀ to 0 (S180). Then, the control unit 13 obtains a value Z obtained by dividing ADY by ADX (S190).

The meaning of the weight B ₀ is as follows.

If the weight B ₀ is 1, the vehicle will travel at an angle within 45 degrees from the north-south center line. On the other hand, if the weight B ₀ is 0, the vehicle will proceed at an angle within 45 degrees from the east-west center line.

When the ratio Z of ADX and ADY is obtained, the controller 13 matches the angle corresponding to the Z value (S200). At this time, the controller 13 calculates the angle [theta] by matching the Z value in the lookup table stored in the lookup table storage unit 14 to match the angle.

The lookup table is stored in the lookup table storage unit 14, which is a kind of ROM, and is a preset value. The look-up table has values of 1 to 45 degrees depending on the Z value.

The control unit 13 calculates the angle [theta] according to the Z value in the look-up table storage unit 14 and then checks the weights (S210).

The weight is composed of the binary number B ₂ B ₁ B ₀ . The control unit 13 calculates a final angle according to a given equation for each weight value when the binary weight is 0 to 3 as a decimal number. If the binary number weight is 4 to 7 as a decimal number, Accordingly, the angle is calculated and then 180 degrees is added to calculate the final absolute angle (S220).

An example of the angle calculation method according to the weight is as follows.

First, it is the final angle calculation method when the decimal weight is 0 ~ 3.

If the binary weight (B ₂ B ₁ B ₀ ) is 000 ₍₂₎ , the weight is 0 ₍₁₀₎ in decimal degrees, and the running angle of the vehicle is between 0 and 45 degrees. At this time, the angle (?) Calculated from the look-up table storage unit 14 according to the Z value is the final angle.

If the binary weight (B ₂ B ₁ B ₀ ) is 001 ₍₂₎ , the weight is 1 ₍₁₀₎ in decimal, and the running angle of the vehicle is between 46 and 90 degrees. At this time, the angle obtained by subtracting the angle (?) Calculated from the look-up table storage unit 14 according to the Z value at the 90 degrees is the final angle.

When the binary weight (B ₂ B ₁ B ₀ ) is 011 ₍₂₎ , the weight is 3 ₍₁₀₎ in decimal degrees and the traveling angle of the vehicle is between 91 and 135 degrees. At this time, the angle obtained by adding 90 degrees to the angle? Calculated according to the Z value from the look-up table storage unit 14 is the final angle.

If the binary weight (B ₂ B ₁ B ₀ ) is 010 ₍₂₎ , the weight is 2 ₍₁₀₎ in decimal, and the traveling angle of the vehicle is between 136 and 180 degrees. At this time, the angle obtained by subtracting the angle (?) Calculated from the look-up table storage unit 14 according to the Z value at the 180 degree is the final angle.

On the other hand, the final angle calculation method when the decimal weight is 4 to 7 is as follows.

When the binary weight (B ₂ B ₁ B ₀ ) is 110 ₍₂₎ , the weight is 6 ₍₁₀₎ in decimal and the traveling angle of the vehicle is between 181 and 225 degrees. At this time, the angle obtained by adding 180 degrees to the angle? Calculated according to the Z value from the look-up table storage unit 14 becomes the final angle.

If the binary weight (B ₂ B ₁ B ₀ ) is 111 ₍₂₎ , the weight is 7 ₍₁₀₎ in decimal, and the running angle of the vehicle is between 226 and 270 degrees. At this time, the angle obtained by adding 180 degrees to the angle obtained by subtracting the angle (?) Calculated from the look-up table storage unit 14 according to the Z value at 90 degrees is the final angle.

If the binary weight (B ₂ B ₁ B ₀ ) is 101 ₍₂₎ , the weight is 5 ₍₁₀₎ in decimal, and the running angle of the vehicle is between 271 and 315 degrees. At this time, the angle obtained by adding 180 degrees to the angle (?) Calculated by the lookup table storage unit 14 in accordance with the Z value plus 90 degrees is the final angle.

Also, when the binary weight (B ₂ B ₁ B ₀ ) is 100 ₍₂₎ , the weight is 4 ₍₁₀₎ in decimal and the running angle of the vehicle is between 316 and 359 degrees. At this time, the angle obtained by subtracting the angle (?) Calculated from the look-up table storage unit 14 according to the Z value at 180 degrees plus 180 degrees is the final angle.

The finally calculated angle becomes an absolute angle, and the traveling direction of the vehicle can be determined according to the absolute angle.

The control unit 13 transmits the calculated absolute angle data to the navigation device control unit 21.

The navigation device control unit 21 determines the traveling direction of the vehicle based on the absolute angle data transmitted from the control unit 13 and allows the display control unit 22 to display the traveling direction of the vehicle on the display unit 23. [

As described in detail above, by using the geomagnetic sensor according to the present invention, the signal of the geomagnetism sensor mounted on the moving object is subjected to analog / digital conversion and an angle is calculated within a predetermined angle range according to the ratio of the output of the converted signal do.

By calculating the weights according to all angles divided by a plurality of geomagnetism sensor outputs, we can calculate the moving angle of the moving object with different simple expressions according to the calculated weights, Can be calculated.

Claims (6)

A geomagnetism sensor provided in a moving body for detecting an earth magnetic field and outputting an X signal and a Y signal; an analog / digital converter for converting an output of the geomagnetism sensor into a digital signal; and an output of the geomagnetism sensor converted by the analog / And a controller for calculating a moving direction of the moving object by receiving the input of the geomagnetism sensor angle as input, A digital conversion step of receiving an output of the geomagnetic sensor as an input, converting the digital signal into digital data, And a weight setting step of setting a weight by the data converted and input in the digital conversion step. An output ratio calculating step of calculating a ratio of the output signal of the geomagnetic sensor according to a set weight after the weight is set after the weight setting step, An angle conversion step of converting the ratio of the output signal of the geomagnetic sensor calculated in the output ratio calculation step to an angle, And an absolute angle calculating step of converting the angles converted in the angle converting step into absolute angles by different equations according to weights. The method according to claim 1, The weight setting step may include a first determining step of determining whether a value obtained by subtracting the X intermediate value from the X output value of the geomagnetic sensor input to the control unit is greater than zero and determining whether the X intermediate value is subtracted from the X output value in the first determining step If the value of the weight is greater than zero, the second digit of the weight is set to 0. If it is determined that the value obtained by subtracting the X intermediate value from the X output value is not greater than zero in the first determination step, A second determining step of determining whether a value obtained by subtracting the Y intermediate value from the Y output value of the geomagnetic sensor input to the control unit is greater than zero; and a second determining step of determining a value obtained by subtracting the Y intermediate value from the Y output value in the second determining step And if it is determined that the value obtained by subtracting the Y intermediate value from the Y output value is not greater than zero, the 4th digit of the weight is set to 1 A third determination step of determining whether a value obtained by subtracting the X output value and the Y output value input to the input unit is greater than zero; and a third determination step wherein a value obtained by subtracting the Y output value from the X output value is greater than 0 A third setting step of setting the number of digits on the face 8 to 0; and a third setting step of setting to 1 if the value obtained by subtracting the Y output from the X output value in the third determination step is greater than zero, A method of calculating a traveling angle using a sensor. 3. The method of claim 2, Wherein the X intermediate value of the weight setting step is an intermediate value between the maximum X output value and the minimum X output value and the Y intermediate value is an intermediate value between the maximum Y output value and the minimum Y output value. 3. The method according to claim 1 or 2, Wherein the output ratio calculation step calculates an output ratio by dividing the Y output value by the X output value when it is determined that the value obtained by subtracting the Y output value from the X output value is greater than zero in the third determination step, And calculating the output ratio by dividing the X output value by the Y output value when it is determined that the reduced value is not greater than zero. The method according to claim 1, Wherein the angle conversion step compares the output ratio calculated in the output ratio calculation step with data of a preset lookup table and converts the angle into an angle. The method according to claim 1, Wherein the absolute angle calculating step calculates an absolute angle by subtracting an angle corresponding to the output ratio from 90 degrees when the weight value converted to a decimal number is 1 when the weight value converted into a decimal number according to the weight value is 0, The angle is an absolute angle, and when the weight value converted to the decimal number is 2, the angle obtained by subtracting the angle according to the output ratio is an absolute angle at 180 degrees, and when the weight value converted into the decimal number is 3, The angle obtained by adding 90 degrees is an absolute angle. When the weight value converted into a decimal number is 4, an angle obtained by adding 180 degrees to the angle when the weight is 2 is an absolute angle. If the weight value converted into a decimal number is 5 When the weight is 3, the angle is 180 degrees plus the absolute angle. If the weight is 6, the angle is 180 degrees plus the weight. And when the weight value converted into a decimal number is 7, an angle obtained by adding 180 degrees to the angle when the weight is 1 is an absolute angle.