KR20060101999A - Method of compensating for sensor signal of magnetic encoder - Google Patents

Abstract

The present invention relates to a method for compensating detection signals of a rotor position sensing device of an AC motor. When an error occurs in the magnitude of a detection signal input from the linear hall sensor due to an assembly error of the linear hall sensor, the more accurate rotation angle can be detected. It relates to a detection signal compensation method of the rotor position sensing device of the AC motor.

,

를 입력 받는 단계; (b) 상기 감지신호

,

를

에 대해 연산하여 회전각 검출 신호 θa 를 산출하는 단계; (c) 상기 감지신호를 변환행렬

에 의해 축변환하여 축변환 신호

(단,

) 를 산출하는 단계; (d) 상기 회전각 검출 신호 θa 가

간격마다 확인되는 상기 축변환 신호값 α= a 및 α=b를 산출하여 일시 저장하는 단계; (e) 상기 감지신호

에 상기 일시저장된 α=b를 상기 감지신호

에 상기 일시저장된 α= a를 곱하여 두 감지신호의 크기를 ab로 동일하게 보상하는 단계 및 (f) 상기 보상된 감지신호를

에 대해 연산하여 회전각 검출 신호 θa를 산출하여 회전각을 확인하는 단계를 포함하여 이루어진다.The detection signal compensation method of the rotor position sensing device of the AC motor of the present invention is provided at the bottom of the rotor of the motor, the permanent magnet formed with two poles with respect to the center axis and the permanent magnet surface in the position off the center of the permanent magnet In the rotor position sensing apparatus of an AC motor comprising two linear Hall sensors installed at an angle of 90 degrees apart from the predetermined distance from the sensor, (a) a sensing signal having amplitudes a and b from the respective linear Hall sensors, respectively.

,

Receiving an input; (b) the detection signal

,

To

Calculating a rotation angle detection signal [theta] a by operating on; (c) converting the detected signal into a matrix

Axis conversion signal by axis conversion by

(only,

Calculating; (d) The rotation angle detection signal θa is

Calculating and temporarily storing the axis transform signal values α = a and α = b which are checked at intervals; (e) the detection signal

The detected signal is stored in

Compensating the magnitudes of the two detection signals equally to ab by multiplying the temporarily stored α = a by (b) correcting the compensated detection signals.

Calculating the rotation angle detection signal θa to confirm the rotation angle.

AC motor, EPS, magnetic encoder, hall sensor

Description

Method for compensating detection signal of rotor position sensor of AC motor {method of compensating for sensor signal of magnetic encoder}

1 is a perspective view schematically showing a magnetic encoder,

2 is a schematic cross-sectional view of a motor having a magnetic encoder;

3A and 3B are graphs of a sensing signal and a sensing signal inputted from a linear Hall sensor without assembly error;

3C and 3D are graphs of a sensed signal inputted from a linear hall sensor having an assembly error and an output signal processed from the sensed signal;

4 is an electrical block diagram for sensing signal compensation of a magnetic encoder according to the present invention.

5 is a graph illustrating an axis transformation according to the present invention;

6A and 6B are graphs of α- and β-axis signals before and after applying the present invention;

7 is a flowchart of a sensing signal compensation method of the rotor position sensing apparatus of the AC motor according to the present invention.

*** Explanation of symbols for the main parts of the drawing ***

100: motor 110: magnetic encoder

111: permanent magnet 113, 115: linear hall sensor

120: rotor 130: stator

210: rotation angle detection 220: axis conversion

230: sampling

The present invention relates to a method for compensating detection signals of a rotor position sensing device of an AC motor. In particular, when an error occurs in a magnitude of a detection signal input from a linear hall sensor due to an assembly error of the linear hall sensor, the detection of a more accurate rotation angle is detected. It relates to a detection signal compensation method of the rotor position sensing device of the AC motor.

Electric Power Steering (EPS) is a system that assists steering power by using the power of the motor when the driver wants to steer in the desired direction. The device enables the driver to easily steer with a small force. . Most of the motors used in EPS have used DC motors in the past, but most of them use AC motors. AC motors should have an encoder that senses the absolute position of the rotor that rotates inside the motor. The encoder is mainly a magnetic SINCOS encoder.

1 is a perspective view schematically showing a magnetic encoder.

As shown in FIG. 1, the magnetic encoder 110 is installed to be spaced apart from the permanent magnet 111 and the permanent magnet 111 installed on the rotor 120 shaft of the motor 100 by a predetermined position. FIG. 2 includes two linear hall sensors 113 and 115 installed to generate a phase difference.

Accordingly, as the rotor 120 rotates, the permanent magnets 111 also rotate, and the linear magnetic sensors 113 and 115 detect a magnetic field that is changed due to the rotation of the permanent magnets 111. By outputting, the absolute position of the rotor 120 is detected.

On the other hand, the magnetic encoder 110, the precision of each measurement varies depending on the accuracy of the detection position of the linear Hall sensors 113, 115, bar of the linear Hall sensors 113, 115 when assembling the magnetic encoder If an error occurs in the position, the magnitudes of the magnetic fields measured by the two linear Hall sensors 113 and 115 are different, which makes accurate rotation angle measurement impossible.

2 is a cross-sectional view schematically illustrating a motor having a magnetic encoder, and illustrates a case in which a linear hall sensor assembly error occurs.

As shown in FIG. 2, a permanent magnet 111 is attached to one surface of the rotor 120 of the motor 110 provided with the rotor 120 and the stator 130, and a predetermined distance from the permanent magnet 111. Linear Hall sensors 113 and 115 spaced apart from each other may cause errors during assembly.

As such, according to the conventional magnetic encoder 110, the price is very low, and the durability and environmental resistance is strong, while the rotation angle measurement according to the accuracy of the detection position of the linear Hall sensors 113 and 115 There was a problem that the precision will be different.

The present invention has been made to solve the above-mentioned problems, the rotor position detection apparatus of the AC motor to correct the rotation angle by correcting the error when the size of the detection signal due to the assembly error of the linear Hall sensor It is an object of the present invention to provide a sensing signal compensation method.

,

를 입력 받는 단계; (b) 상기 감지신호

,

를

에 대해 연산하여 회전각 검출 신호 θa 를 산출하는 단계; (c) 상기 감지신호를 변환행렬

에 의해 축변환하여 축변환 신호

(단,

) 를 산출하는 단계; (d) 상기 회전각 검출 신호 θa 가

간격마다 확인되는 상기 축변환 신호값 α= a 및 α=b를 산출하여 일시 저장하는 단계; (e) 상기 감지신호

에 상기 일시저장된 α=b를 상기 감지신호

에 상기 일시저장된 α= a를 곱하여 두 감지 신호의 크기를 ab로 동일하게 보상하는 단계 및 (f) 상기 보상된 감지신호를

에 대해 연산하여 회전각 검출 신호 θa를 산출하여 회전각을 확인하는 단계를 포함하여 이루어진 교류모터의 로터위치 감지장치의 감지신호 보상 방법을 제공한다.The detection signal compensation method of the rotor position sensing device of the AC motor of the present invention for achieving the above object is provided at the bottom of the rotor of the motor, the center of the permanent magnet and two permanent magnets formed with two poles based on the central axis In the rotor position sensing device of an AC motor comprising two linear Hall sensors installed at an off position at an angle of 90 degrees away from the permanent magnet surface by a predetermined distance, (a) the amplitude a and the respective from each linear Hall sensor. sensing signal with b

,

Receiving an input; (b) the detection signal

,

To

Calculating a rotation angle detection signal [theta] a by operating on; (c) converting the detected signal into a matrix

Axis conversion signal by axis conversion by

(only,

Calculating; (d) The rotation angle detection signal θa is

Calculating and temporarily storing the axis transform signal values α = a and α = b which are checked at intervals; (e) the detection signal

The detected signal is stored in

Multiplying the temporarily stored α = a by and equally compensating the magnitudes of the two sensed signals with ab and (f) correcting the compensated sensed signals.

Comprising the step of calculating the rotation angle detection signal θa to determine the rotation angle provides a sensing signal compensation method of the rotor position sensing apparatus of the AC motor.

Hereinafter, an output signal compensation method of a magnetic encoder according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3A and 3B are graphs of sensing signals inputted from the linear Hall sensors 113 and 115 without assembly errors, and output signal graphs of the sensing signals. FIG. 3A shows the sensing signals, and FIG. 3B shows the output signals. Serve

As shown in FIG. 3A, two signals having the same magnitude and period show a phase difference of 90 °, and when the sense signal is processed, that is, ADC conversion is taken and arctan is used, the ripple is reduced as shown in FIG. 3B. The output signal is omitted, that is, the rotation angle detection signal is converted.

3C and 3D are graphs of a sensing signal inputted from a linear hall sensor having an assembly error and an output signal, and FIG. 3C shows a sensing signal, and FIG. 3D shows an output signal.

As shown in FIG. 3C, two signals having the same period but different in magnitude have a phase difference of 90 °, and when the sense signals are processed, that is, ADC converter takes arctan, as shown in FIG. 3D. The ripple output signal is converted into a rotation angle detection signal.

Therefore, when there is a magnitude error in the detection signal input from the linear Hall sensor as shown in FIG. 3c, in order to convert to the output signal without ripple as shown in FIG. The size error compensation process of multiplying the sampled value by the sensing signal should be added, which will be described with reference to FIGS. 4 and 5.

4 is an electrical block diagram for sensing signal compensation of a magnetic encoder according to the present invention.

As shown in FIG. 4, a block diagram for compensating the detection signal of the magnetic encoder 110 according to the present invention is a rotation angle detection block 210 for generating a rotation angle detection signal by arctanting the detection signal with an ADC and a detection signal. And an sampling block 230 for sampling the axis conversion signal based on the rotation angle detection signal and temporarily storing the axis conversion block 220 to generate an axis conversion signal by performing an axis conversion.

Therefore, the detection signals x and y output from the respective linear Hall sensors 113 and 115 are input to the rotation angle detection block 210 and the axis conversion block 220 so that the detection signals are output from the rotation angle detection block 210. The output signal is processed and output to the sampling block 230. In the axis conversion block 220, the detection signal is converted into an axis conversion signal and output to the sampling block 230. The sampling block 230 receiving the axis conversion 220 signal and the output signal from the axis conversion block 220 and the rotation angle detection block determines an axis corresponding to 0 ° and 90 ° by determining 0 ° and 90 ° of the output signal. By temporarily storing each value of the converted signal and multiplying the stored value by the detection signals x and y so that the two corrected detection signals have the same size, an output signal without ripple, that is, a rotation angle detection signal, can be obtained. .

,

라 할 수 있으며, x, y를 두 축으로 하여 각각의 입력신호에 제곱을 취해주고 정리하면,On the other hand, Figure 5 is a graph for explaining the axis conversion in accordance with the present invention, when the magnitude error of a and b occurs in each of the detection signals of the two linear Hall sensors 113, 115, each input signal is

,

If you take the x and y as two axes and square each input signal,

,

,

,

,

The axis transformation trace g1 of the two input signals on the x and y planes is created.

In this case, the variable is defined as in Equation 1,

축 두 파형을 한번 더 축변환 하면, 수학식2와 같은 가상 축 α, β를 얻을 수 있다.

When the axis two waveforms are converted once again, the virtual axes α and β as shown in Equation 2 can be obtained.

의 관계에 있으며 수학식1 및 수학식2에 의해 β축은 항상 0이 되고 본 발명에서 이용하는

일 경우에 한해 α축을 다음과 같이 전개할 수 있다. here

The β axis is always 0 by the equations (1) and (2).

In one case, the α-axis can be developed as follows.

를 각각 집어넣고 정리하면, 다음과 같은 결론을 얻을 수 있다.In equation (3)

Putting each in and organizing them gives us the following conclusions:

를 곱하고, y축에

을 곱하면, 두 축의 사인파의 크기가 a x b로 동일하게 되어 감지신호의 크기 오차를 보상할 수 있게 된다.These values are the maximum and minimum values of the α axis and are equal to the magnitude error values of each axis. So we can use these values on the x axis

Multiply by the y-axis

When multiplying by, the magnitude of the sine wave of the two axes is equal to axb to compensate for the magnitude error of the detection signal.

When the magnitude error is compensated and there is no difference in the magnitudes of the two axis detection signals, the α axis appears as a straight line having axb as shown in FIG. 6B, and the β axis still outputs 0, so that the detection input to the rotation angle detection block is performed. The signal remains in a size compensated state.

Fig. 6a shows a r-axis signal with ripple and a zero value before application of the present invention, and Fig. 6b shows a β-axis signal with a r-axis and zero value with ripple after application of the present invention. After application, it can be confirmed that α value, that is, axb is 1.

7 is a flowchart of a sensing signal compensation method of the rotor position sensing apparatus of the AC motor according to the present invention.

,

를 입력 받는 단계이며, 단계 S13은 입력받은 감지신호

,

를

에 대해 연산하여 회전각 검출 신호 θa 를 산출하고, 감지신호를 변환행렬

에 의해 축변환하여 축변환 신호

(단,

) 를 산출하는 단계이다.Step S11 is a detection signal from each linear hall sensor

,

Is a step of receiving an input, and step S13 is an input detection signal.

,

To

Compute the rotation angle detection signal θa by converting

Axis conversion signal by axis conversion by

(only,

) Is calculated.

간격마다 확인되는 상기 축변환 신호값 즉, θa 가 0 및

일 때의 축변환 신호값 α=a 및 α=b를 산출하여 일시 저장하는 단계 이며, 단계 S17은 감지신호

에 상기 일시저장된 α=b를 감지신호

에 상기 일시저장된 α=a를 곱하여 두 감지신호의 크기를 ab로 동일하게 보상하는 단계이다.Next step S15 is that the rotation angle detection signal θa is

The axis transform signal value checked every interval, i.e., θa is 0 and

Is a step of calculating and temporarily storing the axis converted signal values α = a and α = b at step S17.

Detects the temporarily stored α = b at

Multiplying the temporarily stored α = a by to equally compensate the magnitude of the two detection signals with ab.

에 대해 연산하여 회전각 검출 신호 θa 를 산출하여 회전각을 확인하는 단계이다.Finally, in step S19, the compensated detection signal is

Calculating a rotation angle detection signal θa to confirm the rotation angle.

이외에

값의 배수 간격을 갖는 두 신호면 어떠한 값이든 허용될 수 있다.On the other hand, when checking the a value from θa in step S15, θa is 0 and

besides

Any value can be allowed if the two signals have multiple intervals of the value.

The detection signal compensation method of the rotor position sensing apparatus of the AC motor of the present invention is not limited to the above-described embodiment and can be modified in various ways within the scope of the technical idea of the present invention.

According to the detection signal compensation method of the rotor position detection device of the AC motor of the present invention as described above, when an error occurs in the magnitude of the detection signal input from the linear Hall sensor due to the assembly error of the linear Hall sensor, it is separately corrected by software. There is an effect that can detect a more accurate rotation angle without the added device of.

Claims (2)

It is provided at the bottom of the rotor of the motor, the permanent magnet with two poles formed on the center axis and two linear Hall sensors installed at an angle of 90 degrees away from the permanent magnet surface by a predetermined distance at a position off the center of the permanent magnet In the rotor position detection device of the AC motor made, including, (a) sensing signals having amplitudes a and b from the respective linear Hall sensors;

,

Receiving an input; (b) the detection signal

,

To

Calculating a rotation angle detection signal [theta] a by operating on; (c) converting the detected signal into a matrix

Axis conversion signal by axis conversion by

(only,

Calculating; (d) The rotation angle detection signal θa is

Calculating and temporarily storing the axis transform signal values α = a and α = b which are checked at intervals; (e) the detection signal

The detected signal is stored in

Multiplying the temporarily stored α = a by and equally compensating the magnitudes of the two detection signals with ab; and (f) the compensated detection signal

And calculating the rotation angle detection signal θa to check the rotation angle. The method of claim 1, In the step (d), the rotation angle detection signal θa is 0 and

Detection signal compensation method of the rotor position detection device of the AC motor.

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