JP7028150B2 - Temperature compensation method for rotation angle detection using a sensor module equipped with a magnetic sensor and a magnetic sensor - Google Patents

Description

The present disclosure relates to a sensor module having a built-in magnetic sensor and a temperature compensation method for rotation angle detection using a magnetic sensor.

Conventionally, a rotation angle detecting device has been used in which a Hall element or an MR element that detects a change in the direction of a magnetic field is used, and a rotation angle of an object to be detected, for example, a valve or the like, is detected in a non-contact manner. There is a temperature dependency in the output of such a detector. Therefore, various methods for compensating the temperature of the detection device have been conventionally proposed (Patent Documents 1, 2, etc. below). Patent Document 1 discloses a configuration in which temperature compensation is performed in a circuit, and Patent Document 2 discloses a configuration in which the non-linearity existing in the output after temperature compensation is compensated. Such a detection device may be molded in the manufacturing process and finally provided in a packaged form (for example, Patent Document 3).

Japanese Unexamined Patent Publication No. 10-38611 Japanese Unexamined Patent Publication No. 2000-2505 Special Table 2010-506157 Gazette

However, when such a rotation angle detection device is mounted on a moving body such as an automobile or equipment in a factory, sufficient accuracy may not be obtained even if temperature compensation is performed. For example, when a rotation angle detection device is used as the throttle valve opening sensor, the angle detection value may include an error depending on the ambient temperature, and the angle detection accuracy may be insufficient. ..

The present disclosure can be realized in the following forms.

According to one embodiment of the present disclosure, a sensor module (100) is provided. This sensor module is a magnetic sensor in which a plurality of detection elements (61, 62) whose characteristics change depending on the direction of the magnetic field are arranged at different rotation angle positions with respect to the object to be detected (15) rotating in the direction of the magnetic field. (60), a temperature specifying unit (85) that specifies the environmental temperature of the magnetic sensor, a fixing material (40) that fixes the magnetic sensor, and the plurality of detections of the magnetic sensor fixed by the fixing material. A correction information storage unit (81, 82) for storing correction information prepared in advance for each detection element corresponding to a temperature error that may occur in each of the elements, and the correction information according to the specified environmental temperature. By referring to the information, the correction calculation unit (71, 72) that individually corrects the signal output by each detection element and the correction calculation signal are used to correspond to the rotation angle of the detected object. It is provided with an angle calculation unit (80) for obtaining and outputting a detected value.

According to the sensor module of this form, the temperature error of a plurality of detection elements is individually corrected and calculated, and the rotation angle of the object to be detected is obtained using the result, so that the detection element is fixed by the fixing material. The angle error caused by the generated ambient temperature can be suppressed.

The schematic diagram which shows typically the cross section of the electronically controlled throttle in 1st Embodiment. The perspective view of the sensor module in 1st Embodiment. A block diagram showing the internal configuration of the sensor module. The schematic diagram which shows the relationship between the detection element contained in a magnetic sensor, and a magnetic field. An explanatory diagram schematically showing the stress generated in the sensor module. An explanatory diagram for explaining an aspect of an error due to the temperature of the detection element in the first embodiment and a method for correcting the error of each aspect. An explanatory diagram for explaining an actual correction method in the first embodiment. The block diagram which shows the internal structure of the sensor module in 2nd Embodiment.

A. First Embodiment:
The sensor module 100 of the first embodiment has a function of detecting the angle of the object to be detected. As shown in FIG. 1, the sensor module 100 of the present embodiment is used for the electronically controlled throttle 10 that controls the amount of intake air to the engine of the vehicle. Specifically, the sensor module 100 of the present embodiment outputs a signal corresponding to the rotation angle of the throttle valve device 13. Of course, the sensor module 100 is provided in another valve, for example, in the case of a vehicle, an EGR valve that controls the exhaust gas recirculation amount of the EGR device, various valves used in the supercharger, a valve that controls the water flow, and the like. It can also be used to detect the opening degree of the rotated valve. It may be used for moving objects other than vehicles and equipment of facilities such as factories, and may be used for detecting the rotation angle of various rotating objects. The rotation angle range to be detected may be 360 degrees or less, or may be geared down to detect a rotation angle of 360 degrees or more.

Prior to the description of the sensor module 100, the electronically controlled throttle 10 will be described. The electronically controlled throttle 10 includes a throttle valve device 13, a housing 14 for accommodating the throttle valve device 13, a magnetic field forming portion 15, a housing cover 16, and a sensor module 100. The housing 14 is formed with an intake passage 17 for introducing air into the engine.

The throttle valve device 13 includes a substantially disk-shaped butterfly valve 12, a rotating shaft 18 that rotatably supports the butterfly valve 12, and a motor 19 that rotates the butterfly valve 12 via the rotating shaft 18. Although not shown, both ends of the rotating shaft 18 are rotatably supported by the housing 14.

The motor 19 of the throttle valve device 13 is controlled by the ECU 25 that controls the operation of the engine, and when the output of the engine is increased by depressing the accelerator pedal (not shown), the butterfly valve 12 is rotated to take in air. The flow path of the passage 17 is opened to increase the amount of intake air. On the other hand, when the output of the engine is reduced, the butterfly valve 12 is rotated in the fully closed direction to reduce the intake air amount.

The ECU 25 detects the opening degree of the butterfly valve 12 in order to control the opening degree of the butterfly valve 12 of the throttle valve device 13 to the target opening degree. The device that detects the rotation angle of the butterfly valve 12 of the throttle valve device 13 is the sensor module 100. As will be described later, this sensor module 100 uses a Hall element to detect the rotation angle of the butterfly valve 12 in a non-contact manner. For this purpose, a cylindrical holder 20 is provided at the end of the rotating shaft 18 on the opposite side of the motor 19. Two magnets 21 and 22 constituting the magnetic field forming portion 15 are provided on the inner wall of the holder 20. The magnetic field forming unit 15 forms a magnetic field in a direction orthogonal to the axial direction of the rotation axis 18 of the throttle valve device 13.

The sensor module 100 is fixed to the housing cover 16. The housing cover 16 is fixed to the housing 14 by screws 23. When the housing cover 16 is fixed by the screw 23, the sensor module 100 is positioned in a non-contact manner and coaxially with the holder 20 which is the magnetic field forming portion 15. The sensor module 100 can exchange electrical signals with the outside, here, the ECU 25, through the wiring 24. The communication between the sensor module 100 and the ECU 25 may be performed by an analog signal or by a communication method for transmitting and receiving a digital signal by a predetermined protocol.

Next, the sensor module 100 will be described with reference to FIG. The sensor module 100 includes a detection element unit 50 and terminals 30 to 33. The detection element unit 50 is a component that outputs an electric signal according to the direction of the magnetic field formed by the magnetic field forming unit 15 (see FIG. 1). The terminals 30 to 33 are members that electrically connect the detection element portion 50 and the wiring 24. The detection element portion 50 and the terminals 30 to 33 are fixed by a fixing material 40 such as resin. In the present embodiment, the detection element portion 50 and the terminals 30 to 33 are housed together with other circuit members described later and integrally molded with a thermosetting resin, but the detection element portion 50 is molded. Since the shape is different from the portion below it, the upper portion is referred to as a detection element fixing portion 41, and the lower portion is referred to as a base portion 43.

As shown in FIG. 3, the detection element unit 50 constituting the sensor module 100 includes an analog / digital converter (hereinafter, ADC) that converts two analog signals output from the magnetic sensor 60 and the magnetic sensor 60 into digital signals. The angle calculation unit 80 and the first are connected to the first and second correction calculation units 71 and 72 and the first and second correction calculation units 71 and 72 connected to the 65, 66 and the ADC 65 and 66, respectively. , The first and second correction information storage units 81 and 82 that output correction information to the second correction calculation units 71 and 72, the environmental temperature sensor 85 that detects the environmental temperature of the detection element unit 50, and the like are built-in. .. The output of the angle calculation unit 80 is connected to the terminal 31. As a result, the terminal 31 is used as a terminal for outputting the detected angle θ, which is the rotation angle signal. The terminal 32 is a terminal for supplying power of voltage Vcc between the terminal and the terminal connected to the ground line GND. The terminal 30 is a metal terminal that is the base of the entire sensor module 100. Each of the circuit components and each of the terminals 30 to 33 are integrally molded by a thermosetting resin which is a fixing material 40.

Inside the magnetic sensor 60, first and second detection elements 61 and 62 for detecting the direction of the magnetic field formed by the magnetic field forming unit 15 are provided. The outputs of the first and second detection elements 61 and 62 are connected to the above-mentioned ADCs 65 and 66, respectively. The first and second detection elements 61 and 62 of the magnetic sensor 60 have a relationship in which the detection angles of the magnetic fields are offset by 90 degrees from each other. This situation is schematically shown in FIG. The magnets 21 and 22 of the magnetic field forming portion 15 are provided at positions facing each other in the radial direction inside the holder 20, and the magnetic sensor 60 is provided at a position at the center of the holder 20. Therefore, the magnetic field MF formed by the magnets 21 and 22 passes through the center of the magnetic sensor 60. Although the holder 20 has an annular shape in FIG. 4, it may have an elliptical shape or the like. Further, in FIG. 4, the first and second detection elements 61 and 62 are provided on opposite surfaces of the rectangular parallelepiped and on surfaces orthogonal to each other, but the phase is relative to the center of the magnetic flux MF. As long as the positional relationship is offset by 90 degrees, the arrangement may be such that they intersect each other or are displaced vertically.

The first and second detection elements 61 and 62 are all Hall elements, are actually extremely small elements, and are arranged in a positional relationship orthogonal to each other. When the magnetic field MF rotates, signals out of phase by 90 degrees are output from the first and second detection elements 61 and 62 in accordance with the rotation. The Hall element outputs a signal according to the strength of the magnetic field penetrating the element from the front. Therefore, the output signal is strongest at the position where the element faces the magnetic field MF, weakest at the position where the magnetic field MF and the element are parallel to each other, and takes positive and negative values depending on the direction of the magnetic field. Therefore, the output of the first detection element 61 and the output of the second detection element 62 have a relationship of cos wave on one side and sine wave on the other side with respect to the angle of the magnetic field MF, that is, the rotation angle θ of the holder 20. There is. Hereinafter, for convenience of explanation, the signal detected by the first detection element 61 is treated as a cos wave, and the signal detected by the second detection element 62 is treated as a sine wave. In the present embodiment, Hall elements are used as the first and second detection elements 61 and 62, but AMR (Anisotropic Magneto Resistive) elements and TMR (Tunnel Magneto Resistance) elements may be used, and GMR (Giant Magneto) may be used. A Resistive) element may be used. Although only the first and second detection elements 61 and 62 arranged in the positional relationship orthogonal to each other are shown in FIG. 4, the magnetic flux in the direction further orthogonal to the detection direction of the magnetic fields of both detection elements 61 and 62 is shown. A chip provided with a third detection element for detection is distributed as a 3D sensor. As the magnetic sensor 60, such a 3D sensor may be used, and two of the detection elements may be used in combination.

In the sensor module 100 of the first embodiment described above, the rotation angle θ of the magnetic field forming unit 15 that rotates according to the rotation angle of the butterfly valve 12 driven by the motor 19 is detected by the detection element unit 50. The error that may occur in the detection of the rotation angle by this sensor module 100 is
(A) Error due to runout between the rotating shaft 18, the magnetic field forming unit 15, and the detection element unit 50 (B) There is an error caused by the temperature of the detection element unit 50. The former error is eliminated by accurately aligning the arrangements of the three so that the rotating shaft 18, the magnetic field forming unit 15, and the detection element unit 50 are coaxial with each other. The latter error is generated by the change in the environmental temperature of the sensor module 100 even if the former error is eliminated.

Therefore, the mechanism of the error generated by the environmental temperature and the method of suppressing this error by the present embodiment will be described with reference to FIGS. 5 and 6. As shown in FIG. 5, the sensor module 100 has a shape in which the detection element fixing portion 41 is formed on the base portion 43. Both are integrally formed to form the fixing material 40, but in order to facilitate die cutting at the time of molding, they have a trapezoidal shape in which the thickness and width become smaller toward the upper part. Further, the detection element fixing portion 41 is provided with a magnetic sensor 60 inside, and is thin so that the magnitude of the magnetic flux component in the sensor normal direction, that is, the direction of the magnetic field can be accurately detected among the magnetic flux penetrating the element. It is made. The arrangement of the components inside the detection element fixing portion 41 is not particularly limited, but among the components shown in FIG. 3, the magnetic sensor 60 is arranged inside the detection element fixing portion 41, and other components other than the magnetic sensor 60 are excluded. The components may be arranged in the base portion 43, or other circuit components may be arranged in the detection element fixing portion 41 together with the magnetic sensor 60. In the arrangement of such parts, it is sufficient that the detection accuracy of the magnetic sensor 60 can be ensured without causing disturbance of the magnetic flux MF.

As shown in FIG. 5, the magnitude of expansion / contraction of the fixing material 40 of the sensor module 100 differs depending on the portion due to the change in the environmental temperature. The width of the upper side of the sensor module 100 is smaller than that of the base portion 43, but as a result of thermal expansion due to a predetermined temperature rise, the stress SC applied in the width direction on the upper side of the detection element fixing portion 41 is in the width direction of the base portion 43. It is smaller than the generated stress SB. Further, the detection element fixing portion 41 is generally thin so as not to interfere with the penetration of the magnetic flux, whereas the base portion 43 accommodates a large number of parts inside, and the thickness thereof is the detection element fixing portion. Thicker than 41. Therefore, the total stress ST related to the detection element fixing portion 41 has at least a two-dimensional stress distribution with respect to the magnetic sensor 60, as shown in FIG. That is, the stresses caused by the temperature changes applied to both the detection elements 61 and 62 built in the magnetic sensor 60 are different.

As described with reference to FIG. 4, the outputs from the first detection element 61 and the second detection element 62 are cos waves and sine waves with respect to an angle of 0 to 360 degrees with respect to the magnetic field MF. The outputs of the first detection element 61 and the second detection element 62 when the alignment is perfect and there is no temperature error are shown in FIG. 6 as <pre-fixation characteristics>. Reference numeral M in FIG. 6 indicates the output before the first detection element 61 is fixed by the fixing material 40, that is, the output of the element alone, and reference numeral N indicates the output before fixing the second detection element 62 from the fixing material 40. The output of each element is shown.

When the first and second detection elements 61 and 62 and other circuit components are fixed by the fixing material 40 and molded and sealed as the detection element fixing portion 41 and the base portion 43, the first detection element 61 and the other circuit components are sealed. The output of the second detection element 62 receives stress due to the molding by the fixing material 40, and causes an error. As shown in FIG. 6, the error occurs as an amplitude error, an offset error, and a phase error even at a reference temperature (for example, 25 ° C. as normal temperature), and these errors depend on the temperature when the temperature further fluctuates. Fluctuate. The error varies depending on the temperature because the fixing material 40 used for the mold expands and contracts depending on the temperature.

The temperature errors of the first detection element 61 and the second detection element 62 show independent characteristics. As shown in FIG. 4, since the first detection element 61 and the second detection element 62 are arranged at right angles, the direction of the stress received by each element is different due to the thermal expansion / contraction of the detection element fixing portion 41. Because. In the present embodiment, these characteristics are measured in advance by the test sensor module, and the first correction information storage unit 81 and the second correction information storage unit 81 and the second are used as information for correcting the error amount generated in the first detection element 61 and the second detection element 62. Each is stored in the correction information storage unit 82. Then, the correction operation is performed. It is the first correction calculation unit 71 and the second correction calculation unit 72 that perform this correction calculation. The first correction calculation unit 71 and the second correction calculation unit 72 are configured as a digital signal processor (DSP), and the first and second detection elements 61 and 62 converted into digital signals via the ADCs 65 and 66. The output is digitally calculated using the correction functions stored in the first and second correction information storage units 81 and 82, and the amplitude error, the offset error, and the phase error are suppressed.

The amplitude error is an error in which the amplitude of the output signals from the first and second detection elements 61 and 62 fluctuates depending on the temperature. The offset error is an error in which the 0 point of the output signal from the first and second detection elements 61 and 62 fluctuates depending on the temperature. The phase error is an error in which the phase of the output signals from the first and second detection elements 61 and 62 fluctuates depending on the temperature. Therefore, as for the information for correcting these errors, a correction function corresponding to the amplitude fluctuation, a correction function corresponding to the offset error, and a correction function corresponding to the phase fluctuation are required for each detection element. In FIG. 6, these correction functions for the first detection element 61 are shown with a “first signal” such as amplitude fluctuation_first signal. Further, the correction function for the second detection element 62 is shown with a “second signal”.

Since each of the amplitude fluctuation, the offset fluctuation, and the phase fluctuation depends on the temperature, the first correction calculation unit 71 and the second correction calculation unit 72 read the environment temperature X from the environment temperature sensor 85 and correspond to the temperature. The first and second signals for correction are read out, and the correction calculation for correcting the outputs of the first detection element 61 and the second detection element 62 is performed using the first and second signals. Since such correction calculation is performed, the outputs of the first correction calculation unit 71 and the second correction calculation unit 72 are <before fixing> regardless of the fluctuation of the environmental temperature, as shown in FIG. 6 as <corrected temperature characteristics>. The characteristics are close to the temperature characteristics>.

The signal ring input after the above correction calculation is completed by the first correction calculation unit 71 and the second correction calculation unit 72, and the angle calculation unit 80 outputs the rotation angle θ of the butterfly valve 12. The angle calculation unit 80 converts the values obtained from the first correction calculation unit 71 and the second correction calculation unit 72 that perform digital calculation into analog signals, and combines the cos wave and the sine wave to obtain the rotation angle θ. Uniquely determined and output in the range of angles 0 to 360 degrees.

An example of a specific operation will be described with reference to FIG. 7. The uppermost part of FIG. 7 shows the breakdown of the sensitivity error generated in the detection element unit 50 fixed by the fixing material 40, <first detection element amplitude error> <second output element amplitude error> <first detection element offset error>. It is shown as <second detection element offset error>. On the other hand, the correction formulas for the correction calculation stored in the first correction information storage unit 81 and the second correction information storage unit 82 are shown as <first detection element correction formula> and <second detection element correction formula>. These correction formulas are obtained as a quadratic function of the environmental temperature X. In fact, the coefficients α1, β1, γ1 of the formula are used for the first detection element correction formula, and the coefficients α1, β1, γ1 of the formula are used for the second detection element correction formula. , The coefficients α2, β2, γ2 of the equation are stored in the first correction information storage unit 81 and the second correction information storage unit 82, respectively. For each coefficient of the quadratic function, the quadratic function that minimizes the error is obtained from the error measured by the test sensor module by using the least squares method or the like.

In this embodiment, a quadratic function is used as the function of the correction formula. Therefore, even if a resin having a glass transition point is used for the fixing material 40 and the properties of the resin (thermal expansion coefficient, etc.) change at the transition point, correction corresponding to this can be performed. Further, the semiconductor used for the magnetic sensor 60 generally generates a leakage current at a predetermined temperature or higher, but even if the characteristics change depending on the presence or absence of the generation of the leak current, the correction corresponding to the leakage current can be performed. It should be noted that the correction formula may be specified by using not only a quadratic function but also a higher-order function. Further, when a material having no transition point is used as the fixing material 40, or when the magnetic sensor 60 is used in a region where a leakage current does not occur, sufficient accuracy can be obtained even with a linear correction formula using a linear function. be able to.

In FIG. 7, as the sensitivity error, the amplitude error and the offset error are collectively corrected by one correction formula, and the phase error is not included. This is because the phase error is corrected differently from the sensitivity error. If necessary, the phase error may be corrected by a correction formula that moves the output signals from the first detection element 61 and the second detection element 62 back and forth on the time axis. However, since the rotation speed of the butterfly valve 12 is not constant, it is desirable to specify the phase error by using the timing when the butterfly valve 12 is fully closed and fully opened and correct it. Of course, the phase error may be excluded from the correction target.

As shown in FIG. 7, the temperature errors of the first detection element 61 and the second detection element 62 have different characteristics. Therefore, by preparing correction formulas corresponding to the temperature errors, the first detection after correction can be performed. The sensitivity fluctuation of the element 61 and the sensitivity fluctuation of the second detection element 62 are corrected, respectively, and the sensitivity fluctuation with respect to the temperature change is sufficiently suppressed. By inputting the corrected signal, the angle calculation unit 80 can calculate the rotation angle θ of the butterfly valve 12 by using the cos wave and the sine wave in which the sensitivity fluctuation is sufficiently suppressed. Therefore, the rotation angle θ of the butterfly valve 12 driven by the motor 19 can be detected with high accuracy, and the amount of air taken into the engine by the throttle valve device 13 can be controlled with high accuracy.

Further, the first correction information storage unit 81 and the second correction information storage unit 82 of the sensor module 100 store only the coefficients α1, β1, γ1 and the coefficients α2, β2, γ2 of the correction formula, and perform the first correction calculation. Since the unit 71 and the second correction calculation unit 72 perform the correction calculation according to the correction formula of the quadratic function using this coefficient, the information to be stored in order to perform the correction calculation with high accuracy can be reduced in capacity.

B. Second embodiment:
Next, the second embodiment will be described. Similar to the first embodiment, the sensor module 200 of the second embodiment detects the rotation angle of the butterfly valve 12 of the throttle valve device 13, and is used in place of the sensor module 100 shown in FIG. Similar to the first embodiment, the sensor module 200 is molded with the detection element portion 150 and other circuit components by the fixing material 40 which is a thermosetting resin.

The internal configuration of the sensor module 200 is shown in FIG. In FIG. 8, the terminals and the like are not shown. In the second embodiment, only one detection element 161 constituting the magnetic sensor 160 is drawn, but as in the first embodiment, two Hall elements are used. Of course, in the second embodiment, a configuration using a single detection element may be used. A temperature compensation circuit 163 is incorporated in the detection element 161. The temperature compensation circuit 163 is a circuit that compensates for the temperature characteristics of the detection element 161 alone. The temperature compensation circuit 163 receives the signal from the temperature sensor 164 and compensates for the fluctuation of the signal of the detection element 161 in a circuit manner. As such a temperature compensation circuit, for example, the circuit shown in Patent Document 1 can be adopted.

In the sensor module 200 of the second embodiment, the magnetic sensor 160 itself performs temperature compensation. The temperature-compensated angle signal (cos wave or sine wave) is output to the angle calculation unit 180 via the ADC 165. The angle calculation unit 180 includes a correction calculation unit 171 and a correction information storage unit 181. Similar to the first embodiment, the correction information storage unit 181 stores information for compensating for an error caused in the magnetic sensor 160 due to fluctuations in the environmental temperature due to being molded by the fixing material 40, for example, a correction formula. .. The angle calculation unit 180 can obtain the correction amount Y from the correction formula using the environment temperature X detected by the environment temperature sensor 185 provided inside the detection element unit 150, and can correct the output of the magnetic sensor 160. As a result, even if the magnetic sensor 160 whose temperature is compensated by the detection element 161 alone is used, the temperature error caused by fixing by the fixing material 40 can be further suppressed, and the accuracy of the sensor module 200 can be improved. .. Of course, it has the same effects as those of the first embodiment, such as using a quadratic function as a correction formula and storing only coefficients. In the second embodiment, the environmental temperature sensor 185 is provided in addition to the temperature sensor 164, but both may be used in combination.

C. Other embodiments:
In the above embodiment, the correction operation uses a quadratic function, but other functions such as a third-order or higher function and a spline function may be used. Further, the calculation may be performed by using linear interpolation or the like in which the section is finely divided. Alternatively, the relationship between the temperature and the sensitivity error is measured in advance, this is stored in the first correction information storage unit 81 or the like in the form of a lookup table, and the lookup table is referred to according to the environmental temperature to obtain the sensitivity error. The correction amount may be obtained and the correction calculation may be performed. The correction operation may be multiplication or addition / subtraction.

In the above embodiment, the detection element as the magnetic sensor is molded by using the resin as the fixing material, but as the material, a material other than the resin, for example, silicon rubber or the like may be used. The resin may be a thermosetting resin that cures when heated and does not return to its original state, or a photocurable resin that cures with light, or a type of resin that has fluidity at the time of filling and then cures, for example, by mixing two liquids. It may be a type of resin. Further, the fixing method is not limited to the molding, and other methods such as potting and hot melt molding may be used. Of course, various types of resins and other materials (such as silicone rubber) can be used for these methods. Further, the detection element may be adhered and fixed to a fixing substrate or the like with a material that also functions as an adhesive. In this case, the adhesive may function not only as a fixing agent but also as a sealing agent. It is also possible to appropriately combine these multiple materials and methods. Further, the fixing material may be any material that fixes the magnetic sensor, and does not necessarily have to be sealed. Regardless of which method is used for fixing, the method of the present disclosure is effective because the output of the magnetic sensor is affected by the change in temperature.

In the above embodiment, the environmental temperature of the magnetic sensor is specified by using the environmental temperature sensors 85, 185, etc., but the temperature specifying part does not have to be limited to the temperature sensor. The temperature may be specified from this.

In the first embodiment, it has been described that the temperature compensation circuit for the magnetic sensor 60 is not particularly provided, but a circuit for performing temperature compensation by the magnetic sensor 60 alone may be provided. In this case, the temperature compensation process as the magnetic sensor 60 may be incorporated into the correction calculation of the first correction calculation unit 71 and the second correction calculation unit 72. Even if the temperature compensation process as the magnetic sensor 60 is incorporated into the correction calculation of the first correction calculation unit 71 and the second correction calculation unit 72, the correction calculation is individually performed for each of the first detection element 61 and the second detection element 62. Therefore, it is possible to improve the detection accuracy of the rotation angle detected by the sensor modules 100 and 200 having different sensitivity errors for each detection element.

In the above embodiment, the two detection elements 61 and 62 are arranged in an orthogonal positional relationship, but it is not necessary to limit them to orthogonality, and if they are shifted by a predetermined angle smaller than 360 degrees, the output signals from the two detection elements can be transmitted. By using it, the rotation angle can be uniquely obtained in the range of 0 to 360 degrees.

In the first embodiment, two detection elements are used, but three or more detection elements may be used. For example, if a magnetic field in a predetermined direction is formed inside a hemispherical object to be detected and the strength of the magnetic field is detected by three Hall elements arranged at positions orthogonal to each other, the rotation of the hemispherical object to be detected can be detected. It can be detected three-dimensionally. Such detection can be applied to detect movements of robot joints and the like.

D. Other aspects:
It can also be implemented by the sensor module shown in the present disclosure or the following aspects. For example, as a first aspect of the sensor module, a magnetic sensor in which a plurality of detection elements whose characteristics change depending on the direction of the magnetic field are arranged at different rotation angle positions with respect to the object to be detected rotating in the direction of the magnetic field. Corresponds to the temperature error that can occur in each of the temperature specifying part that specifies the environmental temperature of the magnetic sensor, the fixing material that fixes the magnetic sensor, and the plurality of detection elements of the magnetic sensor that are fixed by the fixing material. By referring to the correction information storage unit that stores the correction information prepared in advance for each detection element and the correction information according to the specified environmental temperature, the signal output by each detection element can be obtained. It is possible to configure a sensor module including a correction calculation unit for individual correction and an angle calculation unit for obtaining and outputting a detection value corresponding to the rotation angle of the object to be detected by using the correction calculation signal. To perform individual corrections for a plurality of detection elements, the fixing by the fixing material of the sensor module may be released, for example, the two detection elements may be exchanged, and the output of the rotation angle may be observed. If multiple detection elements are individually corrected, even if the same detection element is used, the output of the rotation angle will change if the connection relationship is changed, so know that individual corrections are being performed. Can be done.

In such a sensor module, the magnetic sensor may be sealed with a resin as a fixing material or a potting agent. By doing so, the water resistance and durability of the magnetic sensor can be improved.

In such a sensor module, two detection elements out of the plurality of detection elements are arranged at a predetermined angle of less than 360 degrees with respect to the magnetic field changed by the rotation of the object to be detected, and the correction calculation unit is used. By referring to the information for correction according to the specified environmental temperature, the two output signals output by the two detection elements are assumed to have a phase difference corresponding to the predetermined angle, and correspond to the rotation angle. The detected value may be uniquely obtained. In this way, the sensor module can uniquely determine the rotation angle, and is highly useful as a device for determining the rotation angle.

In such a sensor module, it is also desirable that the two detection elements are arranged at positions orthogonal to each other and the phase difference is 90 degrees. If the phase difference is arranged so as to be 90 degrees, the signals output from the two detection elements have a relationship between a cos wave and a sine wave, and the rotation angle can be easily calculated.

In such a sensor module, the correction information stored in the correction information storage unit corrects an error generated in each detection element according to the stress generated in the magnetic sensor due to the environmental temperature by fixing with the fixing material. It may be information. By doing so, it is possible to correct the error based on the stress caused by the fixing by the fixing material and suppress the decrease in the detection accuracy of the rotation angle due to the environmental temperature.

In such a sensor module, the individual correction performed by the correction calculation unit for the signal output by each detection element may be a correction using a quadratic or higher-order function having the environmental temperature as a variable. By using a higher-order function of a quadratic function or higher, the accuracy of correction can be improved.

In this sensor module, the correction information storage unit stores the coefficient of the higher-order function for each detection element, and the correction calculation unit is stored in the correction information storage unit for each detection element. The correction may be performed by the higher-order function using the coefficient. In this case, it is sufficient to store the coefficients for the correction calculation, and the amount of information to be stored for the correction calculation can be reduced. As a result, the memory capacity and the like can be reduced.

In such a sensor module, the magnetic sensor is provided non-contact with an object to be detected that is rotationally driven by an actuator used in any one of an intake amount control device, an exhaust gas recirculation device, and a supercharger. May be. In this way, the rotation angles of various devices can be detected accurately in a non-contact manner. As a result, the engine can be controlled more accurately.

In such a sensor module, the detection element may be a Hall element or an MR element. An inexpensive commercially available sensor can be used to improve the detection accuracy of the rotation angle.

As a second aspect of the sensor module of the present disclosure, it is a detection element whose characteristics change depending on the direction of the magnetic field, and is a detection element with a temperature compensation circuit incorporating a circuit that compensates for an error due to the temperature of the detection element by itself. Is fixed by the magnetic sensor arranged for the object to be detected rotating in the direction of the magnetic field, the fixing material for fixing the magnetic sensor, the environmental temperature sensor for specifying the environmental temperature of the magnetic sensor, and the fixing material. By referring to the correction information storage unit that stores the correction information prepared in advance and the correction information according to the specified environmental temperature in response to the temperature error that may occur in the magnetic sensor. It is possible to configure a sensor module including a calculation unit that corrects a signal output by the detection element with a temperature compensation circuit and outputs a detection value corresponding to the rotation angle of the object to be detected.

By doing so, it is possible to reduce the temperature error that still exists even if the temperature is compensated by the detection element alone in the sensor module. Whether or not the output of the detection element with the temperature compensation circuit is further corrected by the environmental temperature in this way may be determined by observing the output of the detection value corresponding to the rotation angle in the state where the fixing by the fixing material is released. When the output of the detection element with a temperature compensation circuit is further corrected by the environmental temperature, when the environmental temperature changes, it rotates more when it is not fixed by the fixing material than when it is fixed by the fixing material. The error of the detected value of the angle becomes large. On the other hand, if the output of the detection element with a temperature compensation circuit is not further corrected by the environmental temperature, when the environmental temperature changes, the fixing material is fixed as compared with the case where the fixing material is used for fixing. The error of the detection value of the rotation angle is smaller when there is no fixing by. Therefore, by comparing the case where the fixing material is used and the case where the fixing material is not used, it is possible to easily know which configuration is adopted.

The first aspect of the temperature compensation method for detecting the rotation angle using the magnetic sensor of the present disclosure is to rotate a plurality of detection elements, which are built in the magnetic sensor and whose characteristics change depending on the direction of the magnetic field, in the direction of the magnetic field. The plurality of magnetic sensors of the magnetic sensor fixed by the fixing material are arranged at different rotation angle positions with respect to the detected object, the magnetic sensor is fixed by using the fixing material, the environmental temperature of the magnetic sensor is specified, and the magnetic sensor is fixed by the fixing material. The correction information for each detection element is stored in advance in response to the temperature error that may occur in each of the detection elements, and the correction information is referred to according to the specified environmental temperature. After individually correcting the signal to be output, the detection value corresponding to the rotation angle of the object to be detected is obtained and output. According to the temperature compensation method for detecting the rotation angle using this magnetic sensor, it is possible to suppress fluctuations due to the environmental temperature and accurately detect the detection of the rotation angle of the object to be detected.

The present disclosure is not limited to the above-described embodiment, and can be realized by various configurations within a range not deviating from the gist thereof. For example, the technical features in the present embodiment and modifications corresponding to the technical features in each of the embodiments described in the column of the outline of the invention may be used to solve some or all of the above-mentioned problems, or the above-mentioned ones. It is possible to replace or combine them as appropriate in order to achieve some or all of the effects of. Further, if the technical feature is not described as essential in the present specification, it can be appropriately deleted.

10 electronically controlled throttle, 12 butterfly valve, 13 throttle valve device, 14 housing, 15 magnetic field forming part, 16 housing cover, 17 intake passage, 18 rotating shaft, 19 motor, 20 holder, 21.22 magnet, 23 screw, 24 wiring , 30-34 terminal, 40 fixing material, 41 detection element fixing part, 43 base part, 50 detection element part, 60 magnetometer, 61 first detection element, 62 second detection element, 71 first correction calculation unit, 72nd 2 Correction calculation unit, 80 angle calculation unit, 81 1st correction information storage unit, 82 2nd correction information storage unit, 85 environmental temperature sensor, 100 sensor module, 150 detection element unit, 160 magnetic sensor, 161 detection element, 163 temperature Compensation circuit, 164 temperature sensor, 165 ADC, 171 correction calculation unit, 180 angle calculation unit, 181 correction information storage unit, 185 environmental temperature sensor, 200 sensor module

Claims (11)

It is a sensor module (100)
A magnetic sensor (60) in which a plurality of detection elements (61, 62) whose characteristics change depending on the direction of the magnetic field are arranged at different rotation angle positions with respect to the object to be detected (15) rotating in the direction of the magnetic field.
A temperature specifying unit (85) that specifies the environmental temperature of the magnetic sensor, and
A fixing material (40) for fixing the magnetic sensor and
Each of the plurality of detection elements of the magnetic sensor fixed by the fixing material stores information for correction prepared in advance for each detection element in response to the temperature error that may occur due to the fixing by the fixing material . Correction information storage unit (81,82) and
A correction calculation unit (71, 72) that individually corrects the signal output by each detection element by referring to the correction information according to the specified environmental temperature.
Using the corrected signal, an angle calculation unit (80) that obtains and outputs a detection value corresponding to the rotation angle of the object to be detected, and
Equipped with
The magnetic sensor is sealed with a resin as a fixing material or a potting agent, and is fixed at a position corresponding to the object to be detected.
Sensor module. The sensor module according to claim 1.
Two of the plurality of detection elements are arranged with a predetermined angle within 360 degrees with respect to the magnetic field changed by the rotation of the object to be detected.
The correction calculation unit refers to the information for correction according to the specified environmental temperature, and assumes that the two output signals output by the two detection elements have a phase difference corresponding to the predetermined angle. A sensor module that uniquely obtains a detection value corresponding to the rotation angle. The sensor module according to claim 2 , wherein the two detection elements are arranged at right angles to each other and the phase difference is 90 degrees. The sensor module according to any one of claims 1 to 3 .
The correction information stored in the correction information storage unit is information for correcting an error generated in each of the detection elements according to the stress generated in the magnetic sensor due to the environmental temperature due to the fixing by the fixing material. .. It is a sensor module (100)
A magnetic sensor (60) in which a plurality of detection elements (61, 62) whose characteristics change depending on the direction of the magnetic field are arranged at different rotation angle positions with respect to the object to be detected (15) rotating in the direction of the magnetic field.
A temperature specifying unit (85) that specifies the environmental temperature of the magnetic sensor, and
A fixing material (40) for fixing the magnetic sensor and
A correction information storage unit (81,) that stores correction information prepared in advance for each detection element in response to a temperature error that may occur in each of the plurality of detection elements of the magnetic sensor fixed by the fixing material. 82) and
A correction calculation unit (71, 72) that individually corrects the signal output by each detection element by referring to the correction information according to the specified environmental temperature.
Using the corrected signal, an angle calculation unit (80) that obtains and outputs a detection value corresponding to the rotation angle of the object to be detected, and
Equipped with
The correction information stored in the correction information storage unit is information for correcting an error generated in each of the detection elements according to the stress generated in the magnetic sensor due to the environmental temperature due to the fixing by the fixing material. .. The sensor module according to any one of claims 1 to 5.
The individual correction performed by the correction calculation unit for the signal output by each detection element is a correction using a quadratic or higher-order function with the environmental temperature as a variable. The sensor module according to claim 6.
The correction information storage unit stores the coefficient of the higher-order function for each detection element.
The correction calculation unit is a sensor module that performs the correction by the higher-order function using the coefficient stored in the correction information storage unit for each detection element. The sensor module according to any one of claims 1 to 7.
The magnetic sensor is a sensor module provided in a non-contact manner with respect to an object to be detected, which is rotationally driven by an actuator (19) used in any one of an intake amount control device, an exhaust gas recirculation device, and a supercharger. The sensor module according to any one of claims 1 to 8.
The detection element is a sensor module which is a Hall element or an MR element. It is a sensor module (200)
A detection element (161) whose characteristics change depending on the direction of the magnetic field, and a detection element with a temperature compensation circuit incorporating a circuit (163) that compensates for an error due to the temperature of the detection element by itself, is the direction of the magnetic field. A magnetic sensor (160) placed on the rotating object to be detected, and
A fixing material for fixing the magnetic sensor and
An environmental temperature sensor (185) that specifies the environmental temperature of the magnetic sensor, and
A correction information storage unit (181) for storing correction information prepared in advance in response to a temperature error that may occur in the magnetic sensor due to being fixed by the fixing material.
A calculation that corrects the signal output by the detection element with a temperature compensation circuit and outputs a detection value corresponding to the rotation angle of the object to be detected by referring to the correction information according to the specified environmental temperature. Part (180) and
Sensor module with. It is a temperature compensation method for rotation angle detection using a magnetic sensor.
A plurality of detection elements built in the magnetic sensor whose characteristics change depending on the direction of the magnetic field are arranged at different rotation angle positions with respect to the object to be detected rotating in the direction of the magnetic field.
By sealing the magnetic sensor with a resin as a fixing material or a potting agent, the magnetic sensor is fixed at a position corresponding to the object to be detected .
Identify the environmental temperature of the magnetic sensor and
In each of the plurality of detection elements of the magnetic sensor fixed by the fixing material, information for correction for each detection element is stored in advance in response to the temperature error that may occur due to the fixing by the fixing material .
By referring to the information for correction according to the specified environmental temperature, the signal output by each detection element is individually corrected, and then the detection value corresponding to the rotation angle of the object to be detected is obtained and output. A temperature compensation method for rotation angle detection using a magnetic sensor.

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