KR20230149964A - Apparatus for sensing - Google Patents

Abstract

Examples include rotors; A stator disposed to correspond to the rotor; A first collector disposed above the stator and a second collector disposed below the stator; and a first sensor and a second sensor disposed between the first collector and the second collector, wherein the first collector is It includes a first unit collector and a second unit collector, and a compensation coefficient based on the difference between the sensing value of the first sensor transmitted to the first unit collector and the sensing value of the second sensor transmitted to the second unit collector Compensates the sensing value of at least one of the first sensor and the second sensor based on the offset multiplied by the offset of the latest offset among the plurality of sequentially input offsets and the average value of the plurality of sequentially input offsets. If the difference value is greater than the reference value, the sensing value of at least one of the first sensor and the second sensor is compensated based on the latest offset, and if the difference value between the latest offset and the average value is not greater than the reference value, A sensing device that compensates for the sensing value of at least one of the first sensor and the second sensor based on the average value may be provided.

Description

Sensing device {APPARATUS FOR SENSING}

Embodiments relate to sensing devices.

The power steering system (Electronic Power System, hereinafter referred to as 'EPS') drives a motor from an electronic control unit according to driving conditions to ensure turning stability and provide rapid restoration, thereby ensuring driver safety. Makes driving possible.

EPS includes a sensor device that measures steering shaft torque and steering angle to provide appropriate torque. The sensor device is a device that measures the degree of twist of the torsion bar. The torsion bar's steering shaft is an input shaft connected to the handle, an output shaft connected to the power transmission component on the wheel side, and a member connecting the input shaft and the output shaft.

The sensor device includes a housing, a rotor, a stator including stator teeth, and a collector. At this time, the collector is placed outside the stator tooth. Therefore, when an external magnetic field is generated, there is a problem that the collector acts as a path for the external magnetic field, affecting the magnetic flux value of the sensor. If the sensor is affected in this way, the output value of the sensor device changes, causing a problem in which the degree of twist of the torsion bar cannot be accurately measured.

The purpose of the embodiment is to provide a sensing device that can compensate for the amount of change in the output value of the sensor due to external magnetism.

The embodiment includes a rotor, a stator disposed to correspond to the rotor, a first collector disposed above the stator, a second collector disposed below the stator, and disposed between the first collector and the second collector. Includes a first sensor and a second sensor, wherein the first collector includes a first unit collector and a second unit collector, and the sensed value of the first sensor and the second unit collector are transmitted to the first unit collector. The sensing value of at least one of the first sensor and the second sensor is compensated based on an offset obtained by multiplying the difference value of the sensing value of the second sensor transmitted by a compensation coefficient, and among the plurality of offsets that are sequentially input If the difference between the latest offset and the average value of the plurality of sequentially input offsets is greater than the reference value, the sensing value of at least one of the first sensor and the second sensor is compensated based on the latest offset, and If the difference between the latest offset and the average value is not greater than the reference value, a sensing device can be provided that compensates for the sensing value of at least one of the first sensor and the second sensor based on the average value.

The embodiment has the advantage of securing the performance of the sensor device by varying the magnetic resistance of the collector and compensating for the change in output value due to external magnetism.

The embodiment has the advantage of reducing the size of the compensation value because it utilizes the difference in magnetic flux values between collectors even if the external magnetism greatly increases.

The embodiment has the advantage of being able to compensate for the change in output value due to external magnetism without significantly changing the existing collector structure.

The embodiment has the advantage of removing noise generated in the process of compensating for the change in output value due to external magnetism.

The embodiment has the advantage of preventing compensation time delay that may occur in the process of removing noise.

1 is a perspective view showing a sensing device according to an embodiment;
Figure 2 is an exploded view of the sensing device shown in Figure 1;
Figure 3 is a front view of the sensing device shown in Figure 1;
4 is a perspective view showing a first unit collector;
5 is a perspective view showing a second unit collector;
6 is a perspective view showing a third unit collector;
7 is a perspective view showing a fourth unit collector;
8 and 9 are diagrams showing a first unit collector, a second unit collector, a third unit collector, and a fourth unit collector;
10 is a diagram showing a first unit collector and a second unit collector;
11 is a diagram showing a sensing device according to another embodiment;
FIG. 12 is a diagram showing the first unit collector, second unit collector, and third unit collector shown in FIG. 11;
Figure 13 is a graph showing the process of compensating the sensitivity of the first sensor and the sensitivity of the second sensor in the absence of external magnetism;
Figure 14 is a graph showing the process of compensating the sensitivity of the first sensor and the sensitivity of the second sensor in the presence of external magnetism;
Figure 15 is a graph comparing the sensing value of the first sensor and the sensing value of the second sensor when there is no external magnetism;
Figure 16 is a graph comparing the sensing value of the first sensor and the sensing value of the second sensor when there is external magnetism (1500A/m);
Figure 17 is a graph comparing the sensing value of the first sensor and the sensing value of the second sensor when there is relatively strong external magnetism (4500A/m);
Figure 18 is a diagram showing the compensation coefficient corresponding to the change in the third gap and the shape of the collector;
Figure 19 is a diagram showing the process of removing noise generated in the process of compensating for the change in output value due to external magnetism;
20 is a table showing the average value of offset,
21 is a graph comparing the output voltage of the sensing device according to the comparative example and the output voltage of the sensing device according to the embodiment;
Figure 22 is a table showing the delay phenomenon according to application of the average value of the offset;
23 is a graph showing the delay phenomenon according to application of the average value of the offset;
Figure 24 is a diagram showing a process for reducing compensation delay in the process of removing noise;
Figure 25 is a graph showing a state in which compensation delay is reduced.

Hereinafter, the direction perpendicular to the axial direction of the sensing device is called the radial direction, and the direction along a circle with a radial radius centered on the axis is called the circumferential direction.

FIG. 1 is a perspective view showing a sensing device according to an embodiment, FIG. 2 is an exploded view of the sensing device shown in FIG. 1, and FIG. 3 is a front view of the sensing device shown in FIG. 1.

1 to 3, the sensing device according to the embodiment includes a stator 100, a rotor 200 partially disposed on the stator 100, a first collector 300, a second collector 400, and It may include a first sensor (T1) and a second sensor (T2).

Here, the stator 100 may be connected to an output shaft (not shown), and the rotor 200, at least a portion of which is rotatably disposed on the stator 100, may be connected to an input shaft (not shown), but is not necessarily limited thereto. At this time, the rotor 200 may be arranged to rotate with respect to the stator 100. Hereinafter, the inside refers to a direction disposed toward the center based on the radial direction, and the outside may refer to a direction opposite to the inside.

The stator 100, the first collector 300, and the second collector 400 may be fixed to separate holders or housings.

The stator 100 may include a first stator tooth 110 and a second stator tooth 120.

The rotor 200 may include a magnet 210. The magnet 210 may be placed inside the stator 100. The magnet 210 may be connected to the input shaft through a separate holder.

The first sensor T1 and the second sensor T2 detect changes in the magnetic field that occur between the stator 100 and the rotor 200, respectively. The first sensor (T1) and the second sensor (T2) may be Hall ICs. Based on the detected change in magnetic field, the sensing device measures torque.

The first collector 300 may be placed above the stator 100. The second collector 400 may be placed below the stator 100 . The first sensor T1 is disposed to correspond to the first collector 300 and the second collector 400. The second sensor T2 is also disposed to correspond to the first collector 300 and the second collector 400.

The first collector 300 may include a first unit collector 310 and a second unit collector 320. The first unit collector 310 is a collector that is relatively less affected by external magnetism, and the second unit collector 320 is a collector that is relatively more affected by external magnetism. The difference in the sensed value between the first unit collector 310 and the second unit collector 420 is used to compensate for the change in the sensed value due to the external magnetic field.

The first unit collector 310 may include a first plate 311 and a first leg 312. The first leg 312 protrudes from the first plate 311 and is disposed to extend in a direction toward the first collector 300. The first leg 312 is disposed to correspond to the first sensor T1.

The second unit collector 320 may include a second plate 321 and a second leg 322. The second plate 321 is disposed to overlap the first plate 311 in the axial direction. The second plate 321 may be placed above the first plate 311. The second leg 322 protrudes from the second plate 321 and is disposed to extend in a direction toward the second collector 400 . The second leg 322 is disposed to correspond to the second sensor T2.

The second collector 400 may include a third unit collector 410 and a fourth unit collector 420. The third unit collector 410 is a collector that is relatively less affected by external magnetism, and the fourth unit collector 420 is a collector that is relatively more affected by external magnetism. The difference in the sensed value between the third unit collector 410 and the fourth unit collector 420 is used to compensate for the change in the sensed value due to the external magnetic field.

The third unit collector 410 may include a third plate 411 and a third leg 412. The third leg 412 protrudes from the third plate 411 and is disposed to extend in a direction toward the first collector 300 . The third leg 412 is disposed to correspond to the first sensor T1.

The fourth unit collector 420 may include a fourth plate 421 and a fourth leg 422. The fourth plate 421 is arranged to overlap the third plate 411 in the axial direction. The third plate 411 may be disposed below the fourth plate 421. The fourth leg 422 protrudes from the fourth plate 421 and is disposed to extend in a direction toward the first collector 300 . The fourth leg 422 is disposed to correspond to the second sensor T2.

Figure 4 is a perspective view showing the first unit collector 310.

Referring to FIG. 4 , the first unit collector 310 may include a first plate 311 and a first leg 312. The first plate 311 is a flat member and may include a first body 311a and a first extension portion 311b. The first body 311a may have a curved inner surface. The first body 311a may include a plurality of fastening holes H1 for fixing the first unit collector 310. The first extension portion 311b is disposed to extend outward from the first body 311a. This first plate 311 may be fixed to a separate housing. The first leg 312 may be formed by bending the first extension portion 311b. The first leg 312 may include a first leg body 312a and a first tip 312b. The first leg body 312a is arranged to be bent downward from the first extension portion 311b. And the first tip 312b is bent in the circumferential direction on the first leg body 312a and disposed opposite to the first sensor T1.

Figure 5 is a perspective view showing the second unit collector 320.

Referring to FIG. 5 , the second unit collector 320 may include a second plate 321 and a second leg 322. The second plate 321 is a flat member and may include a second body 321a and a second extension portion 322b. The second body 321a may have a curved inner surface. The second body 321a may include a plurality of fastening holes H2 for fixing the second unit collector 320. The second extension portion 322b is disposed to extend outward from the second body 321a. This second plate 321 may be fixed to a separate housing. The second leg 322 may be formed by bending the second extension portion 322b. The second leg 322 may include a second leg body 322a and a second tip 322b. The second leg body 322a is disposed to be bent downward from the second extension portion 322b. And the second tip 322b is bent to the second leg body 322a and disposed to face the second sensor T2.

Figure 6 is a perspective view showing the third unit collector 410.

Referring to FIG. 6 , the third unit collector 410 may include a third plate 411 and a third leg 412. The third plate 411 is a flat member and may include a third body 411a and a third extension portion 411b. The third body 411a may have a curved inner surface. The third body 411a may include a plurality of fastening holes H3 for fixing the third unit collector 410. The third extension portion 411b is disposed to extend outward from the third body 411a. This third plate 411 may be fixed to a separate housing. The third leg 412 may be formed by bending the third extension portion 411b. The third leg 412 may include a third leg body 412a and a third tip 412b. The third leg body 412a is disposed to be bent upward from the third extension portion 411b. And the third tip 412b is bent in the circumferential direction on the third leg body 412a and disposed opposite to the first sensor T1. This third unit collector 410 may have the same shape and size as the first unit collector 310.

Figure 7 is a perspective view showing the fourth unit collector 420.

Referring to FIG. 7 , the fourth unit collector 420 may include a fourth plate 421 and a fourth leg 422. The fourth plate 421 is a flat member and may include a fourth body 421a and a fourth extension portion 421b. The fourth body 421a may have a curved inner surface. The fourth body 421a may include a plurality of fastening holes H4 for fixing the fourth unit collector 420. The fourth extension portion 421b is disposed to extend outward from the fourth body 421a. This fourth plate 421 may be fixed to a separate housing. The fourth leg 422 may be formed by bending the fourth extension portion 421b. The fourth leg 422 may include a fourth leg body 422a and a fourth tip 422b. The fourth leg body 422a is disposed to be bent upward from the fourth extension portion 421b. And the fourth tip 422b is bent in the circumferential direction on the fourth leg body 422a and disposed to face the second sensor T2. This fourth unit collector 420 may have the same shape and size as the second unit collector 320.

8 and 9 are diagrams showing a first unit collector 310, a second unit collector 320, a third unit collector 410, and a fourth unit collector 420.

Referring to FIGS. 1, 8, and 9, the first collector 300 may be disposed on one side of the first sensor T1 and the second sensor T2 in the axial direction. The second collector 400 may be disposed on the other side of the first sensor T1 and the second sensor T2. In the axial direction, a first gap G1 is disposed between the first leg 312 of the first collector 300 and the third leg 412 of the second collector 400. The first leg 312 and the third leg 412 are arranged to overlap in the axial direction. Additionally, a second gap G2 is disposed between the second leg 322 of the first collector 300 and the fourth leg 422 of the second collector 400 in the axial direction. The second leg 322 and the fourth leg 422 are arranged to overlap in the axial direction. The first gap G1 and the second gap G2 each act as magnetic resistance.

The first plate 311 of the first unit collector 310 and the second plate 321 of the second unit collector 320 form an overlap area A1 in the axial direction. The second plate 321 is disposed above the first plate 311 to block external magnetism from flowing toward the first plate 311 and guides the external magnetism to the first leg 312. The first plate 311 and the second plate 321 are arranged with a third gap G3 in the axial direction. This gap acts as magnetic resistance in the first unit collector 310.

The third plate 411 of the third unit collector 410 and the fourth plate 421 of the fourth unit collector 420 may form an overlap area A2 in the axial direction. The fourth plate 421 is disposed below the third plate 411 to block external magnetism from flowing toward the third plate 411 and guides the external magnetism to the fourth leg 422. The third plate 411 and the fourth plate 421 are disposed with a fourth gap G4 in the axial direction. This gap acts as magnetic resistance in the third unit collector 410.

When external magnetism is generated, the external magnetism flows along the first path (P1) passing through the second plate (321), the second leg (322), the second sensor (T2), and the fourth leg (422). also. External magnetism flows along the second path P2 that passes through the second plate 321, the first plate 311, the first leg 312, the first sensor T1, and the third leg 412.

While the first path (P1) has only magnetic resistance due to the second gap (G2), the second path (P2) has magnetic resistance in addition to the first gap (G1) due to the third gap (G3). exist. Therefore, a relatively large amount of magnetic flux flows through the first path (P1). Therefore, in response to external magnetism, a difference occurs between the sensing value measured by the first sensor (T1) and the sensing value measured by the second sensor (T2).

Although not shown in the drawing, when external magnetism flows from the second collector 400 side, it is the same as when it flows from the first collector 300 side. A magnetic flux flow is formed, causing a difference between the sensing value measured by the first sensor (T1) and the sensing value measured by the second sensor (T2).

In this first collector 300, first, the second plate 321 covers the first plate 311, and guides the external magnetism flowing toward the first leg 312 to flow toward the second leg 322, and secondly, By forming resistance to external magnetism through the third gap G3 formed between the first plate 311 and the second plate 321, the sensing value measured by the first sensor T1 and the 2 Creates a difference in the sensing value measured by the sensor (T2). This is the same for the second collector 400.

The size of the third gap G3 may be 2.0 mm to 3.5 mm. If the size of the third gap G3 is less than 2.0 mm, the magnetic resistance for the third gap G3 is not sufficient, and if the size of the third gap G3 is larger than 3.5 mm, there is a limit to the compensation coefficient. There is a problem that the axial length of the sensing device increases.

Meanwhile, the axial length L2 of the second leg 322 is longer than the axial length L1 of the first leg 312. And the axial length L3 of the third leg 412 is longer than the axial length L4 of the fourth leg 422. For example, the ratio of the axial length L1 of the first leg 312 and the axial length L2 of the second leg 322 may be 1:1.1 to 1:1.2. Additionally, the ratio of the third length to the fourth leg 422 in the axial direction may be 1:1.1 to 1:1.2.

FIG. 10 is a diagram illustrating a first unit collector 310 and a second unit collector 320.

Referring to FIG. 10, the size of the first unit collector 310 is set in consideration of the overlap area and position with the second unit collector 320. For example, when viewed in the axial direction, the area of the overlap area A1 of the first plate 311 and the second plate 321 may be within 50% to 100% of the area of the first plate 311. there is. The overlap area (A1) of the first plate 311 and the second plate 321 must be at least 50% of the area of the first plate 311 in order for the sensing value measured by the first sensor (T1) and the second sensor to be calculated. In (T2), a meaningful difference value between the measured sensing values can be derived. Although not shown in the drawing, when viewed in the axial direction, the area of the overlap area of the third plate 411 and the fourth plate 421 may also be within 50% to 100% of the area of the third plate 411. .

Meanwhile, the ratio of the circumferential length K1 of the inner surface of the first plate 311 and the circumferential length K2 of the inner surface of the second plate 321 may be within 1:1.3 to 1:1.7. Although not shown in the drawing, the ratio of the circumferential length of the inner surface of the third plate 411 to the circumferential length of the inner surface of the fourth plate 421 may be within 1:1.3 to 1:1.7.

FIG. 11 is a diagram showing a sensing device according to another embodiment, and FIG. 12 is a diagram showing the first unit collector 310, the second unit collector 320, and the third unit collector 410 shown in FIG. 11. It is a drawing.

11 and 12, a sensing device according to another embodiment is a first collector 300, including a first unit collector 310 and a second unit collector 320, and a second collector 400. As such, it may include only the third unit collector 410. That is, the collector corresponding to external magnetism may be disposed on only one side of the stator 100.

For example, only the third unit collector 410 is disposed on the lower side of the stator 100, and the third unit collector 410 includes a third plate 411, a third leg 412, and a fifth leg 413. ) may include. The third leg 412 extends from one side of the third plate 411, and the fifth leg 413 extends from the other side of the third plate 411.

A second gap G2 is disposed between the second leg 322 of the first collector 300 and the fifth leg 413 of the second collector 400 in the axial direction. The second leg 322 and the fifth leg 413 are arranged to overlap in the axial direction.

When external magnetism is generated, the external magnetism flows along the first path (P1) passing through the second plate (321), the second leg (322), the second sensor (T2), and the fifth leg (413). also. External magnetism flows along the second path P2 that passes through the second plate 321, the first plate 311, the first leg 312, the first sensor T1, and the third leg 412.

In this sensing device, the process of compensating the sensing value of the first sensor (T1) and the sensing value of the second sensor (T2) corresponding to external magnetism is as follows.

The sensing value of the first sensor T1 is compensated by Equation 1 below.

Here, T1c is the compensated sensing value of the first sensor (T1), T1o is the sensing value before compensation of the first sensor (T1), T2o is the sensing value before compensation of the second sensor (T2), and a is the sensing value before compensation of the first sensor (T1). 1 It is a compensation coefficient corresponding to the axial separation distance (third gap G3) between the first unit collector 310 and the second unit collector 320 in the sensor T1.

And the sensing value of the second sensor T2 is compensated by Equation 2 below.

Here, T2c is the compensated sensing value of the second sensor (T2), T1o is the sensing value before compensation of the second sensor (T2), T2o is the sensing value before compensation of the second sensor (T2), and b is It is a compensation coefficient corresponding to the axial separation distance (third gap G3) between the first unit collector 310 and the second unit collector 320 in the second sensor T2.

a and b may be preset values corresponding to the third gap G3. a and b may also vary depending on the shape of the second unit collector 320 or the third unit collector 410.

Hereinafter, the description will be based on the case where a is 2.72 and b is 3.72.

Figure 13 is a graph showing the process of compensating the sensitivity of the first sensor (T1) and the sensitivity of the second sensor (T2) in the absence of external magnetism. As shown in (a) in FIG. 13, there is a difference in sensitivity between the first sensor T1 and the second sensor T2 in the absence of external magnetism in response to magnetic flux. The sensitivity of the second sensor (T2) is lower than that of the first sensor (T1). In the absence of external magnetism, the sensitivity of the first sensor (T1) and the sensitivity of the second sensor (T2) are as shown in (b) in FIG. 13, the sensing value (output angle) of the first sensor (T1) and the second sensor Compensation can be made immediately in the process of outputting the sensing value (output angle) of (T2).

Figure 14 is a graph showing the process of compensating the sensitivity of the first sensor (T1) and the sensitivity of the second sensor (T2) in the presence of external magnetism.

As shown in (a) of FIG. 14, when there is external magnetism, the first sensor (T1) and the second sensor (T2) are affected by the external magnetism. Accordingly, an offset (G1) occurs in the first sensor (T1), and a relatively large offset (G2) occurs in the second sensor (T2). Therefore, in the condition of external magnetism, as shown in (b) in FIG. 14, the sensing value (T1o) of the first sensor (T1) even after compensating for the sensitivity of the first sensor (T1) and the sensitivity of the second sensor (T2) An offset occurs in the sensing value (T2o) of the and second sensor (T2), respectively.

Due to this offset, the sensing value (T1o) of the first sensor (T1) and the sensing value (T2o) of the second sensor (T2) have a constant difference value (T1o-T2o) in the entire angle range.

Figure 15 is a graph comparing the sensing value of the first sensor (T1) and the sensing value of the second sensor (T2) when there is no external magnetism. In Figure 15, (a) shows the sensing value of the first sensor (T1) and the sensing value of the second sensor (T2) before compensation, and (b) in Figure 15 shows the sensing value of the first sensor (T1) after compensation. It shows the value and the sensing value of the second sensor (T2).

In the case where there is no external magnetism, as can be seen in Equations 1 and 2, the sensing value of the first sensor (T1) and the sensing value of the second sensor (T2) are the same, that is, T2o-T1o becomes 0, so compensation The sensing value of the first sensor T1 before and the sensing value of the first sensor T1 after compensation are the same. And the sensing value of the second sensor (T2) before compensation and the sensing value of the second sensor (T2) after compensation are the same.

Figure 16 is a graph comparing the sensing value of the first sensor (T1) and the sensing value of the second sensor (T2) when there is external magnetism (1500 A/m). In FIG. 16, (a) shows the sensing value of the first sensor (T1) and the sensing value of the second sensor (T2) before compensation, and (b) in FIG. 16 shows the sensing value of the first sensor (T1) after compensation. It shows the value and the sensing value of the second sensor (T2). When there is external magnetism (1500A/m), the difference value (T2o-T1o) between the sensing value of the first sensor (T1) and the sensing value of the second sensor (T2) is detected as 0.54. When a is 2.72 and b:3.72, the compensated sensing value of the first sensor (T1) is obtained through Equation 1, and the compensated sensing value of the second sensor (T2) is obtained through Equation 2. As shown in (b) in Figure 16, it can be confirmed that the compensated sensing value of the first sensor (T1) and the compensated sensing value of the second sensor (T2) match, so that offset does not occur and is compensated.

Figure 17 is a graph comparing the sensing value of the first sensor (T1) and the sensing value of the second sensor (T2) when there is relatively strong external magnetism (4500A/m). In FIG. 17, (a) shows the sensing value of the first sensor (T1) and the sensing value of the second sensor (T2) before compensation, and (b) in FIG. 17 shows the sensing value of the first sensor (T1) after compensation. It shows the value and the sensing value of the second sensor (T2).

When there is a relatively strong external magnetism (4500A/m), the difference value (T2o-T1o) between the sensing value of the first sensor (T1) and the sensing value of the second sensor (T2) is detected as 1.62. When a is 2.72 and b:3.72, the compensated sensing value of the first sensor (T1) is obtained through Equation 1, and the compensated sensing value of the second sensor (T2) is obtained through Equation 2. As shown in (b) in Fig. 17, a small offset (0.002deg) occurs. It can be seen that the compensated sensing value of the first sensor (T1) and the compensated sensing value of the second sensor (T2) are almost identical.

Figure 18 is a diagram showing the compensation coefficient corresponding to the change in the third gap G3 and the shape of the collector.

In FIG. 18 (a) shows a sensing device with the third gap G3 set to 3.15 mm, and in FIG. 18 (b) shows a sensing device with the third gap G3 set to 2.15 mm. In Figure 18, (c) is set the same as (b) with the third gap (G3) set to 2.15 mm, and a part of the collector is removed like M in (c) to change the collector size to (a) or (b). ) is set smaller than that.

Comparing (b) and (c), there is almost no difference in compensation coefficient, and it can be seen that the shape of the collector does not significantly affect the compensation coefficient. However, when comparing (a) and (b), the difference in compensation coefficient is large, and it can be seen that the difference in the third gap G3 greatly affects the compensation coefficient.

Meanwhile, due to the self-noise of the first sensor (T1) or the self-noise of the second sensor (T2), noise in the sensing value of the compensated first sensor (T1) or the self-noise of the compensated second sensor (T2) Noise in sensing values may increase significantly.

FIG. 19 is a diagram illustrating the process of removing noise generated in the process of compensating for the change in output value due to external magnetism, and FIG. 20 is a table showing the average value of the offset.

Referring to FIGS. 19 and 20, in order to remove such noise, the sensing device according to the embodiment detects the sensing value of the first sensor T1 or the second sensor based on the average value of a plurality of sequentially input offsets. The sensing value of (T2) can be compensated.

What is offset? As a value obtained by multiplying the difference between the sensing value of the first sensor (T1) transmitted to the first unit collector 310 and the sensing value of the second sensor (T2) transmitted to the second unit collector 320 by the compensation coefficient , is the value represented by a*(T2o-T1o) in Equation 1 or b*(T2o-T1o) in Equation 2, respectively.

This offset can be calculated at regular intervals. For example, as shown in FIG. 20, based on the input sensing value of the first sensor (T1) and the sensing value of the second sensor (T2), the order 1, 2, 3... . Offsets can be calculated at regular intervals. The offset of order 1 may be 0.003V, the offset of order 2 may be 0.0051V, and the offset of order 3 may be 0.0051V.

In order to remove noise, the sensing value of the first sensor (T1) or the sensing value of the second sensor (T2) can be compensated based on the average value from the nth offset to the n-(m-1)th offset. there is. m is a positive integer greater than 1. n is a positive integer greater than m. For example, the sensing value of the first sensor (T1) or the sensing value of the second sensor (T2) may be compensated based on the average value of the most recent m offsets among the plurality of offsets.

The specific process for removing noise is as follows.

Offsets are calculated and input sequentially (S10).

Check whether the number of offsets is greater than m. (S20)

If the number of offsets is greater than m, for example, if m is 4 and the number of offsets becomes 4, the average value of the four most recent offsets is calculated. (S30) For example, the current offset is the offset of order 4. If so, 0.0047V, which is the average value of the offset in order 1, the offset in order 2, the offset in order 3, and the offset in order 4, can be selected as the offset.

And if the current offset is the offset of order 5, 0.0051V, which is the average value of the offset of order 2, the offset of order 3, the offset of order 4, and the offset of order 5, can be selected as the offset.

Using the average value calculated in this way (e.g., 0.0047V, 0.0051V) as an offset, the sensor value of the first sensor (T1) is compensated and the sensor value of the second sensor (T2) is compensated through Equation 1 or Equation 2, respectively. Sensor values can be compensated (S40).

Figure 21 is a graph comparing the output voltage of the sensing device according to the comparative example and the output voltage of the sensing device according to the embodiment.

Referring to FIG. 21, the output voltage of the sensing device according to the comparative example is obtained by compensating the sensor value of the first sensor (T1) and the sensor value of the second sensor (T2) without applying an average value, and in the embodiment The output voltage of the corresponding sensing device is obtained by compensating the sensor value of the first sensor (T1) and the sensor value of the second sensor (T2) through an offset obtained by applying the average value of the four latest offsets.

As a result of measuring about 5000 offsets, in the case of the comparative example, the process of compensating the sensor value of the first sensor (T1) and the sensor value of the second sensor (T2) through Equation 1 and Equation 2, respectively, involves a compensation coefficient In the multiplied state, since the offset is applied as is in Equation 1 and Equation 2, it can be confirmed that the amplitude of the output voltage appears large and the noise is amplified.

On the other hand, in the case of the embodiment, since the offset obtained by applying the average value of the latest four offsets is applied to Equation 1 and Equation 2, it can be confirmed that the amplitude of the output voltage appears relatively small and noise amplification is prevented.

FIG. 22 is a table showing the delay phenomenon according to application of the average value of the offset, and FIG. 23 is a graph showing the delay phenomenon according to the application of the average value of the offset.

Referring to FIGS. 22 and 23, when the average value of the offset is used to compensate for the sensing value of the first sensor (T1) or the sensing value of the second sensor (T2), there is a delay in reaching the actual offset value. A phenomenon occurs.

For example, when an offset is applied in order 12 by an external magnetic field, when applying the average value of the latest 5 offsets, when order 16 is reached, compensation is performed normally, so the time until compensation is It is delayed.

Therefore, the sensing device according to the embodiment seeks to solve this problem by selectively applying the offset and the average value of the offset when making compensation.

FIG. 24 is a diagram showing a process for reducing compensation delay in the process of removing noise, and FIG. 25 is a graph showing a state in which compensation delay is reduced.

Referring to FIG. 24, offsets are sequentially calculated and input (S10), and it is checked whether the number of offsets is greater than m (S20). If the number of offsets is greater than m, the average value of the most recent m offsets is calculated. .(S30)

Then, it is compared to see whether the difference between the most recent offset and the average value of the most recent m offsets is greater than the reference value (R) (S50). The reference value (R) is a preset value. For example, the reference value may be 0.003.

If the difference between the most recent offset and the average value of the most recent m offsets is greater than the reference value, it is considered that compensation delay has occurred, and the average value is not applied for compensation, but the latest offset is applied, and the first sensor ( The sensor value of T1) or the sensor value of the second sensor (T2) is compensated.

For example, when the reference value is 0.003, as shown in FIG. 22, at number 12, the difference between 10.0, the most recent offset, and 2.0, the average value of the five most recent offsets, is 8.0, so at number 12 Instead of applying 2.0, which is the average value of the offset, 10.0, which is the offset of sequence number 12, is applied to compensate for the sensor value of the first sensor (T1) or the sensor value of the second sensor (T2).

On the other hand, if the difference between the most recent offset and the average value of the most recent m offsets is not greater than the reference value, it is considered that there is no compensation delay, and the average value is applied to compensate for the sensor value of the first sensor (T1) or The sensor value of the second sensor (T2) is compensated. In sections where there is no compensation delay, compensation is performed by applying the average value, which has the advantage of improving noise.

As shown in FIG. 25, V1 represents the output change amount obtained by applying compensation only through offset without the process of improving noise by applying the average value. Through V1 in Figure 25, it can be seen that the amplitude of the output change appears large and the noise is amplified.

V2 represents the output change amount with noise improved by applying the average value. Unlike V1, it can be seen that the amplitude of the output change is greatly reduced and the noise is improved. However, when the output fluctuates significantly due to an external magnetic field, such as in the section with 20m/s as the starting point, and when applying the average value to improve noise, the output change converges to the compensated value only at the 35ms point. This can be confirmed by the occurrence of delayed compensation.

In this delay compensation section, the output change can be directly compensated like V3 by applying offset instead of applying the average value. And at the end of the delay compensation section, the average value can be applied to obtain the output change with noise improved.

The above-described embodiments can be used in various devices such as vehicles or home appliances.

100: Stater
200: rotor
210: Magnet
300: first collector
310: first unit collector
311: first plate
312: first leg
320: second unit collector
321: second plate
322: second leg
400: second collector
410: Third unit collector
411: third plate
412: Third leg
420: Fourth unit collector
421: fourth plate
422: 4th leg
410: third plate
420: Third unit collector
421: Third leg
430: fourth plate
440: Fourth unit collector
441: 4th leg

Claims (10)

rotor;
A stator disposed to correspond to the rotor;
A first collector disposed above the stator and a second collector disposed below the stator; And
Comprising a first sensor and a second sensor disposed between the first collector and the second collector,
The first collector includes a first unit collector and a second unit collector,
Based on an offset obtained by multiplying the difference between the sensing value of the first sensor transmitted to the first unit collector and the sensing value of the second sensor transmitted to the second unit collector, the first sensor and the second sensor 2 Compensate the sensing value of at least one of the sensors,
If the difference between the latest offset among the plurality of sequentially input offsets and the average value of the plurality of sequentially input offsets is greater than the reference value, at least one of the first sensor and the second sensor is based on the latest offset. Compensating for one sensing value,
A sensing device that compensates for the sensing value of at least one of the first sensor and the second sensor based on the average value, if the difference between the latest offset and the average value is not greater than a reference value. According to claim 1,
The average value is an average value from the nth offset to the n-(m-1)th offset, where m is a positive integer greater than 1, and n is a positive integer greater than m. According to clause 2,
A sensing device that is the average value of the most recent m offsets among a plurality of offsets. According to claim 1,
A sensing device in which the sensing value of the first sensor is compensated with a compensation value calculated by Equation 1 below.
Equation 1
T1c=T1o-a*(T2o-T1o)
Here, T1c is the compensated sensing value of the first sensor, T1o is the pre-compensated sensing value of the first sensor, T2o is the pre-compensated sensing value of the second sensor, and a is the first unit collector and the second sensor. It is a compensation coefficient corresponding to the axial separation distance of the unit collector. According to clause 4,
A sensing device that compensates the sensing value of the second sensor with a compensation value calculated by Equation 2 below.
Equation 2
T2c=T2o-b*(T2o-T1o)
Here, T2c is the compensated sensing value of the second sensor, T1o is the pre-compensated sensing value of the second sensor, T2o is the pre-compensated sensing value of the second sensor, and b is the first unit collector and the second sensor. It is a compensation coefficient corresponding to the axial separation distance of the unit collector. According to claim 1,
The first unit collector includes a first plate and a first leg protruding from the first plate and extending in a direction toward the second collector,
The second unit collector includes a second plate and a second leg protruding from the second plate and extending in a direction toward the second collector,
A sensing device wherein the first plate and the second plate are spaced apart from each other. According to clause 6,
A sensing device in which the first plate overlaps and is spaced apart from the second plate in the axial direction. According to clause 7,
A sensing device wherein the axial length of the second leg is longer than the axial length of the first leg. According to clause 8,
The second collector includes a third unit collector and a first unit collector,
The third unit collector includes a third plate and a third leg protruding from the third plate and extending in a direction toward the first collector,
The fourth unit collector includes a fourth plate and a fourth leg protruding from the fourth plate and extending in a direction toward the first collector,
The third plate and the fourth plate are spaced apart from each other. According to clause 9,
The third plate is spaced apart from the fourth plate in the axial direction and overlaps.

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