WO2020121929A1

WO2020121929A1 - Sensor module comprising magnetic sensor and method for compensating for temperature in rotation angle detection using magnetic sensor

Info

Publication number: WO2020121929A1
Application number: PCT/JP2019/047547
Authority: WO
Inventors: 卓祐伊藤; 河野　禎之; 智之滝口
Original assignee: 株式会社デンソー
Priority date: 2018-12-10
Filing date: 2019-12-05
Publication date: 2020-06-18
Also published as: JP7028150B2; JP2020094816A

Abstract

A fixing material 40 is used to fix a magnetic sensor 60 in which a plurality of detection elements 61, 62 having characteristics that vary according to a magnetic field direction are disposed at different rotation angle positions in relation to an object 15 for detection that is to have the magnetic field direction thereof rotated. For each of the plurality of detection elements of the magnetic sensor fixed using the fixing material, correction information is stored beforehand that corresponds to the temperature error that can occur in the detection element. A detection value corresponding to the rotation angle of the object for detection is determined after the signals output by the detection elements are individually corrected through referencing of the correction information according to the ambient temperature, and the determined detection value is output. This makes it possible to detect the rotation angle of the object for detection while suppressing accuracy reduction resulting from ambient temperature fluctuation.

Description

SENSOR MODULE WITH MAGNETIC SENSOR AND TEMPERATURE COMPENSATION METHOD FOR Detecting Rotation Angle Using Magnetic Sensor

Cross-reference of related applications

This application is based on Patent Application No. 2018-230750 filed in Japan on Dec. 10, 2018 and claims the benefit of its priority, and the entire content of the patent application is , Incorporated herein by reference.

The present disclosure relates to a sensor module including a magnetic sensor and a temperature compensation method for detecting a rotation angle using the magnetic sensor.

Conventionally, a rotation angle detection device that detects the rotation angle of an object to be detected, such as a valve, in a non-contact manner by using a Hall element or MR element that detects changes in the direction of the magnetic field has been used. The output of such a detection device has temperature dependence. Therefore, various methods for compensating the temperature of the detection device have been conventionally proposed. For example, Japanese Patent Application Laid-Open No. 10-39611 discloses a circuit for temperature compensation, and Japanese Patent Application Laid-Open No. 2000-2505 describes a configuration for compensating for non-linearity existing in an output after temperature compensation. Each is disclosed. Such a detection device may be provided in the form of being molded during the manufacturing process and finally housed in a package, as described in Japanese Patent Publication No. 2010-506157.

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

The present disclosure can be implemented as the following forms.

According to one aspect of the present disclosure, a sensor module is provided. This sensor module includes a magnetic sensor in which a plurality of detection elements whose characteristics change according to the direction of a magnetic field are arranged at different rotation angle positions with respect to an object rotating in the direction of the magnetic field, and an environmental temperature of the magnetic sensor. Corresponding to the temperature error that may occur in each of the plurality of detecting elements of the magnetic sensor fixed by the fixing member that fixes the magnetic sensor and the temperature specifying unit that specifies the magnetic sensor. The correction information storage unit that stores the correction information prepared in advance, and the correction calculation that individually corrects the signal output from each detection element by referring to the correction information according to the specified environmental temperature. And an angle calculation unit that obtains and outputs a detection value corresponding to the rotation angle of the detected object using the corrected and calculated signal.

According to the sensor module of this aspect, the temperature error of the plurality of detection elements is individually corrected and calculated, and the rotation angle of the detected object is obtained using the result, whereby the detection element is fixed by the fixing member. It is possible to suppress the angle error caused by the generated environmental temperature.

FIG. 1 is a schematic view schematically showing a cross section of the electronically controlled throttle according to the first embodiment, FIG. 2 is a perspective view of the sensor module according to the first embodiment, FIG. 3 is a block diagram showing the internal configuration of the sensor module, FIG. 4 is a schematic diagram showing the relationship between the detection element included in the magnetic sensor and the magnetic field, FIG. 5 is an explanatory view schematically showing the stress generated in the sensor module, FIG. 6 is an explanatory diagram for explaining a mode of an error due to the temperature of the detection element and a method of correcting the error of each mode in the first embodiment, FIG. 7 is an explanatory diagram for explaining an actual correction method in the first embodiment, FIG. 8 is a block diagram showing the internal configuration of the sensor module according to the second embodiment.

A. First embodiment:
The sensor module 100 of the first embodiment has a function of detecting the angle of the detected object. As shown in FIG. 1, the sensor module 100 of this embodiment is used for an electronically controlled throttle 10 that controls the amount of intake air to the engine of a vehicle. Specifically, the sensor module 100 of the present embodiment outputs a signal according 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 a supercharger, a valve that controls a water flow, or the like. It can also be used to detect the opening of a rotated valve. It may be used in a moving body other than a vehicle or in equipment of a facility such as a factory, and may be used to detect the rotation angles of various rotating bodies. The rotation angle range to be detected may be 360 degrees or less, or may be gear 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 that houses the throttle valve device 13, a magnetic field forming unit 15, a housing cover 16, and a sensor module 100. An intake passage 17 for introducing air into the engine is formed in the housing 14.

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

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

The ECU 25 detects the opening of the butterfly valve 12 in order to control the opening of the butterfly valve 12 of the throttle valve device 13 to the target opening. The sensor module 100 is a device that detects the rotation angle of the butterfly valve 12 of the throttle valve device 13. 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 reason, a cylindrical holder 20 is provided at the end of the rotary shaft 18 opposite to the motor 19. On the inner wall of the holder 20, two

magnets

21 and 22 forming the magnetic field forming unit 15 are provided. The magnetic field forming unit 15 forms a magnetic field in a direction orthogonal to the axial direction of the rotary shaft 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 with screws 23. When the housing cover 16 is fixed with the screws 23, the sensor module 100 is positioned coaxially with the holder 20 that is the magnetic field forming unit 15 in a non-contact manner. The sensor module 100 is capable of exchanging electrical signals with the outside, here the ECU 25, through the wiring 24. The sensor module 100 and the ECU 25 may be exchanged by an analog signal or a communication method of 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 section 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 unit 50 and the wiring 24. The detection element unit 50 and the terminals 30 to 33 are fixed by a fixing member 40 such as resin. In the present embodiment, the detection element unit 50 and the terminals 30 to 33 are housed together with other circuit members described later and are integrally molded with the thermosetting resin. Since the shape is different from that of the lower part, the upper part is called the detection element fixing part 41 and the lower part is called the base part 43.

As shown in FIG. 3, the detection element unit 50 constituting the sensor module 100 includes a magnetic sensor 60 and an analog-digital converter (hereinafter referred to as ADC) that converts two analog signals output from the magnetic sensor 60 into digital signals. 65, 66, first and second correction calculation units 71, 72 connected to the ADCs 65, 66, respectively, an angle calculation unit 80 connected to the first and second correction calculation units 71, 72, a first The first and second correction

information storage units

81 and 82 that output information for correction 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 incorporated. .. The output of the angle calculator 80 is connected to the terminal 31. As a result, the terminal 31 is used as a terminal for outputting the detected rotation angle signal angle θ. The terminal 32 is a terminal that supplies a power supply of the voltage Vcc to the terminal connected to the ground line GND. The terminal 30 is a metal terminal that serves as a base for the entire sensor module 100. The above-mentioned circuit constituent members and the terminals 30 to 33 are integrally molded with a thermosetting resin which is the fixing member 40.

Inside the magnetic sensor 60, first and

second detection elements

61 and 62 that detect 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 field are deviated from each other by 90 degrees. This state is schematically shown in FIG. The

magnets

21 and 22 of the magnetic field forming unit 15 are provided inside the holder 20 at positions facing each other in the radial direction, and the magnetic sensor 60 is provided at the center position 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 the surfaces of the rectangular parallelepiped which are opposed to each other and are orthogonal to each other, but the phase with respect to the center of the magnetic flux MF is different. As long as the positional relationship is shifted by 90 degrees, the arrangement may intersect with each other or the arrangement may be shifted vertically.

Each of the first and

second detection elements

61 and 62 is a Hall element, and is actually an extremely small element, and they are arranged in a positional relationship orthogonal to each other. When the magnetic field MF rotates, the first and

second detection elements

61 and 62 correspondingly output signals whose phases are shifted by 90 degrees. The Hall element outputs a signal according to the strength of the magnetic field that penetrates 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 has 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 that one is a cos wave and the other is a sin wave 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, a signal detected by the first detection element 61 is treated as a cos wave, and a signal detected by the second detection element 62 is treated as a sin wave. In the present embodiment, Hall elements are used as the first and

second detection elements

61 and 62, but an AMR (Anisotropic Magneto Resistive) element or a TMR (Tunnel Magneto Resistance) element may be used, and a GMR (Giant Magnetoto). Resistive) element may be used. Although FIG. 4 shows only the first and

second detection elements

61 and 62 arranged in a positional relationship orthogonal to each other, a magnetic flux in a direction further orthogonal to the magnetic field detection direction of both

detection elements

61 and 62 is shown. A chip including a third detection element for detecting is distributed as a 3D sensor. Such a 3D sensor may be used as the magnetic sensor 60, and two detection elements may be used in combination.

In the sensor module 100 of the first embodiment described above, the detection element unit 50 detects the rotation angle θ of the magnetic field forming unit 15 that rotates in accordance with the rotation angle of the butterfly valve 12 driven by the motor 19. The error that can occur in the detection of the rotation angle by the sensor module 100 includes
(A) An error due to center deviation of the rotary 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 three positions so that the rotary shaft 18, the magnetic field forming unit 15, and the detection element unit 50 are coaxial. The latter error occurs due to the environmental temperature of the sensor module 100 changing even if the former error is eliminated.

Therefore, the mechanism of the error caused by the environmental temperature and the method of suppressing this error according to 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 of them are integrally formed to form the fixing member 40, but have a trapezoidal shape in which the thickness and the width become smaller toward the upper part in order to facilitate the die cutting at the time of molding. 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 of the magnetic flux penetrating the element, that is, the direction of the magnetic field can be accurately detected. Is made. The arrangement of 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 the magnetic sensor 60 other than the magnetic sensor 60 is arranged. The components may be arranged on the base portion 43, or other circuit components may be arranged on the detection element fixing portion 41 together with the magnetic sensor 60. The arrangement of such components may be such that the magnetic flux MF is not disturbed and the detection accuracy of the magnetic sensor 60 can be secured.

As shown in FIG. 5, the magnitude of expansion/contraction of the fixing member 40 of the sensor module 100 varies depending on the site due to changes in the environmental temperature. The width of the upper side of the sensor module 100 is smaller than that of the base portion 43. However, as a result of thermal expansion accompanying a predetermined temperature rise, the stress SC applied to the upper side of the detection element fixing portion 41 in the width direction 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 prevent the penetration of magnetic flux, whereas the base portion 43 accommodates a large number of components therein, and therefore the thickness is the same as 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 stress due to the temperature change applied to both the

detection elements

61 and 62 incorporated in the magnetic sensor 60 is different.

As described with reference to FIG. 4, the outputs from the first detection element 61 and the second detection element 62 become cos wave and sin wave with respect to the angle 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 they are perfectly aligned and have no temperature error are shown in FIG. 6 as <characteristics before fixation>. Reference numeral M in FIG. 6 indicates the output before the first detection element 61 is fixed by the fixing member 40, that is, the output of the element alone, and reference numeral N indicates before the second detection element 62 is fixed by the fixing member 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 output of the second detection element 62 receives stress due to the molding by the fixing material 40 and causes an error. The error occurs as an amplitude error, an offset error, and a phase error even at a reference temperature (for example, 25° C. as a normal temperature) as shown in FIG. 6, but these errors depend on the temperature when the temperature further fluctuates. Fluctuates. The error fluctuates 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 orthogonally to each other, the directions of stress applied to the respective elements by the thermal expansion/contraction of the detection element fixing portion 41 are different. Because. In the present embodiment, such characteristics are measured by the test sensor module in advance, and as the information for correcting the error amount generated in the first detection element 61 and the second detection element 62, the first correction information storage section 81 and the second correction information storage section are used. Each is stored in the correction information storage unit 82. Then, correction calculation is performed. The first correction calculation unit 71 and the second correction calculation unit 72 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 of 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 to suppress the amplitude error, offset error, and phase error.

The amplitude error is an error in which the amplitudes of the output signals from the first and

second detection elements

61 and 62 vary with temperature. The offset error is an error in which the zero point of the output signals from the first and

second detection elements

61 and 62 varies depending on the temperature. The phase error is an error in which the phases of the output signals from the first and

second detection elements

61 and 62 vary with temperature. Therefore, information for correcting these errors also requires 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 for each detection element. In FIG. 6, these correction functions for the first detection element 61 are shown with the “first signal” added, such as “amplitude variation_first signal”. The correction function for the second detection element 62 is shown with the "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 environmental temperature X from the environmental temperature sensor 85 and respond to the temperature. The correction first and second signals are read out and the correction signals are used to perform the correction calculation for correcting the outputs of the first detection element 61 and the second detection element 62. Since such correction calculation is performed, the outputs of the first correction calculation unit 71 and the second correction calculation unit 72 are as shown in FIG. 6 as <corrected temperature characteristics>, regardless of variations in the environmental temperature. The characteristics are close to the temperature characteristics>.

The signal wheel that has undergone the above-described correction calculation by the first correction calculation unit 71 and the second correction calculation unit 72 is input, and the angle calculation unit 80 outputs the rotation angle θ of the butterfly valve 12. The angle calculation unit 80 converts the value obtained from the first correction calculation unit 71 and the second correction calculation unit 72 that perform digital calculation into an analog signal, and combines the cos wave and the sin wave to calculate the rotation angle θ. It is uniquely determined and output in the range of an angle of 0 to 360 degrees.

An example of a specific calculation will be explained using 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 member 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 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><second detection element correction formula>. These correction equations are obtained as a quadratic function of the ambient temperature X. In practice, the coefficients α1, β1, γ1 of the equations for the first detection element correction equation are 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. Each coefficient of the quadratic function is obtained from the error measured by the test sensor module by using a least square method or the like to obtain a quadratic function that minimizes the error.

In this embodiment, a quadratic function is used as the function of the correction formula. Therefore, even if the resin having the glass transition point is used for the fixing material 40 and the property (coefficient of thermal expansion or the like) of the resin changes at the transition point, the corresponding correction can be performed. Further, a semiconductor used for the magnetic sensor 60 generally causes a leak current at a temperature equal to or higher than a predetermined temperature. However, even if the characteristics change depending on whether or not the leak current is generated, it is possible to perform a correction corresponding thereto. Note that the correction equation may be specified using a higher-order function instead of the quadratic 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 leak current does not occur, sufficient accuracy can be obtained even with a linear correction equation using a linear function. be able to.

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

As shown in FIG. 7, the temperature error between the first detection element 61 and the second detection element 62 has different characteristics. Therefore, by preparing the correction formulas corresponding to the temperature error respectively, the first detection after the correction The sensitivity fluctuation of the element 61 and the sensitivity fluctuation of the second detection element 62 are respectively corrected, and the sensitivity fluctuation with respect to the temperature change is sufficiently suppressed. By inputting the corrected signal, the angle calculator 80 can calculate the rotation angle θ of the butterfly valve 12 by using the cos wave and the sin wave in which the sensitivity variation is sufficiently suppressed. Therefore, the rotation angle θ of the butterfly valve 12 driven by the motor 19 can be accurately detected, and the intake air amount to the engine by the throttle valve device 13 can be accurately controlled.

Furthermore, 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 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 stored in order to perform the accurate correction calculation can have a small capacity.

B. Second embodiment:
Next, a second embodiment will be described. The sensor module 200 of the second embodiment detects the rotation angle of the butterfly valve 12 of the throttle valve device 13 as in the first embodiment, 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 section 150 and other circuit components by the fixing material 40 which is a thermosetting resin.

The internal structure of this sensor module 200 is shown in FIG. In FIG. 8, terminals and the like are omitted. In the second embodiment, only one detection element 161 forming the magnetic sensor 160 is drawn, but two Hall elements are used as in the first embodiment. Needless to say, the second embodiment may have a configuration using a single detection element. A temperature compensating circuit 163 is incorporated in the detecting element 161. The temperature compensating circuit 163 is a circuit that compensates the temperature characteristic of the detection element 161 alone. The temperature compensating circuit 163 receives the signal from the temperature sensor 164 and compensates the fluctuation of the signal of the detecting 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 sin wave) is output to the angle calculator 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 an error generated in the magnetic sensor 160 due to a change in environmental temperature due to being molded by the fixing material 40, for example, a correction formula. .. The angle calculation unit 180 can use the environmental temperature X detected by the environmental temperature sensor 185 provided inside the detection element unit 150 to obtain the correction amount Y from the correction formula and 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 with the fixing member 40 can be further suppressed, and the accuracy of the sensor module 200 can be improved. .. Needless to say, the same operational effects as those of the first embodiment can be obtained in that a quadratic function is used as the correction formula, only the coefficient is stored, and the like. In addition, in the second embodiment, the environmental temperature sensor 185 is provided in addition to the temperature sensor 164, but both may be used together.

C. Other embodiments:
Although the quadratic function is used for the correction calculation in the above-described embodiment, other functions such as a cubic or higher function and a spline function may be used. Further, the calculation may be performed using linear interpolation or the like in which the section is finely divided. Alternatively, by measuring the relationship between the temperature and the sensitivity error in advance and storing this in the form of a lookup table in the first correction information storage unit 81 or the like, and referring to the lookup table according to the environmental temperature, the sensitivity error A correction amount may be obtained and correction calculation may be performed. The correction calculation 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 a material other than the resin, for example, silicon rubber may be used as the material. 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 by light, or a resin of a type that has fluidity when filled and that cures afterwards, for example, a mixture of two liquids. It may be a resin of the type. The fixing method is not limited to the mold, and other methods such as potting and hot melt molding may be used. It goes without saying that various types of resins and other materials (for example, silicone rubber) can be used for these methods. Further, the detection element may be adhered and fixed to the 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. Further, it is also possible to appropriately combine a plurality of such materials and methods. Further, the fixing material may be one that fixes the magnetic sensor and does not necessarily need to be sealed. Whichever method is used, the output of the magnetic sensor is affected by the change in temperature, so the method of the present disclosure is effective.

In the above-described embodiment, the environmental temperature of the magnetic sensor is specified by using the

environmental temperature sensors

85, 185 and the like, but the temperature specifying unit does not need to be limited to the temperature sensor. Alternatively, the temperature may be detected from the above, and the temperature may be specified from this.

In the first embodiment, the temperature compensation circuit for the magnetic sensor 60 has been described as not particularly provided, but the magnetic sensor 60 may be provided with a circuit for performing temperature compensation by itself. In this case, the temperature compensation processing as the magnetic sensor 60 may be incorporated in the correction calculation of the first correction calculation unit 71 and the second correction calculation unit 72. Even if the temperature compensation processing as the magnetic sensor 60 is incorporated in the correction calculation of the first correction calculation unit 71 and the second correction calculation unit 72, individual correction calculation is 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, 62 are arranged in a positional relationship orthogonal to each other. However, the detection signals need not be limited to the orthogonal ones. If they are shifted by a predetermined angle smaller than 360 degrees, the output signals from the two detection elements are 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 hemisphere-shaped object to be detected and the strength of this magnetic field is detected by three Hall elements arranged at mutually orthogonal positions, rotation of the hemispherical object to be detected is detected. It can be detected three-dimensionally. Such detection can be applied to detect the movement of the joints of the robot.

D. Other aspects:
It can 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 according to the direction of a magnetic field are arranged at different rotation angle positions with respect to an object to be detected rotating in the direction of the magnetic field, Corresponding to a temperature error that may occur in each of the temperature specifying unit that specifies the environmental temperature of the magnetic sensor, the fixing member that fixes the magnetic sensor, and the plurality of detection elements of the magnetic sensor that are fixed by the fixing member. Then, 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 from each detection element It is possible to configure a sensor module that includes a correction calculation unit that individually corrects and an angle calculation unit that calculates and outputs a detection value corresponding to the rotation angle of the detected object by using the corrected calculation signal. In order to individually correct a plurality of detection elements, it is sufficient to release the fixation of the sensor module by the fixing material, replace two detection elements, and observe the output of the rotation angle. If individual corrections are made to multiple detection elements, 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 made. You can

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 of the plurality of detection elements are arranged so as to be displaced by a predetermined angle of less than 360 degrees with respect to the magnetic field that changes due to rotation of the object to be detected, and the correction calculation unit By referring to the correction information according to the specified environmental temperature, the two output signals output by the two detection elements are regarded as having 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 preferable that the two detection elements are arranged at positions orthogonal to each other and the phase difference is 90 degrees. If they are arranged so that the phase difference is 90 degrees, the signals output from the two detection elements have a relationship between the cos wave and the sin wave, and the rotation angle can be easily calculated.

In such a sensor module, the correction information stored in the correction information storage unit is fixed by the fixing material to correct an error generated in each of the detection elements according to a stress generated in the magnetic sensor due to the environmental temperature. It may be information. This makes it possible to correct an error based on the stress generated by the fixing by the fixing member and suppress the decrease in the detection accuracy of the rotation angle due to the ambient temperature.

In such a sensor module, the individual correction performed by the correction calculation unit with respect to the signal output from each of the detection elements may be a correction using a quadratic or higher-order function having the environmental temperature as a variable. The accuracy of correction can be improved by using a higher-order function that is a quadratic function or higher.

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 coefficient may be used to perform the correction by the higher-order function. In this case, it is sufficient to store the coefficient 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 in non-contact with an object to be detected, which is rotationally driven by an actuator used for any one of an intake air amount control device, an exhaust gas recirculation device, and a supercharger. May be This makes it possible to accurately detect the rotation angles of various devices 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. The detection accuracy of the rotation angle can be increased by using an inexpensive commercially available sensor.

As a second aspect of the sensor module of the present disclosure, a detection element whose characteristics change depending on the direction of a magnetic field, the detection element with a temperature compensation circuit incorporating a circuit for compensating an error due to the temperature of the detection element by the detection element alone. A magnetic sensor arranged with respect to an object rotating in the direction of the magnetic field, a fixing member for fixing the magnetic sensor, an environmental temperature sensor for specifying the environmental temperature of the magnetic sensor, and the fixing member for fixing By referring to the correction information according to the temperature error that may occur in the magnetic sensor, the correction information storage unit that stores the correction information prepared in advance and the correction information according to the specified environmental temperature. And a calculation unit that corrects a signal output from the detection element with the temperature compensation circuit and outputs a detection value corresponding to the rotation angle of the detected object.

By doing this, it is possible to reduce the temperature error that still exists even if temperature compensation is performed on the detection element alone in the sensor module. In this way, whether the output of the detection element with the temperature compensation circuit is further corrected by the ambient temperature can be determined by observing the output of the detected 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 temperature compensation circuit is further corrected by the ambient temperature, when the ambient temperature changes, the rotation without fixing by the fixing material is better than that by fixing with 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 the temperature compensation circuit is not corrected by the ambient temperature, the fixing material will not be used when the ambient temperature changes, compared to when the fixing material is used. The error in the detected value of the rotation angle is smaller when there is no fixation due to. 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 used.

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

The present disclosure is not limited to the above-described embodiments, and can be realized with various configurations without departing from the spirit thereof. For example, in order to solve some or all of the above-mentioned problems, the present embodiment corresponding to the technical features in each mode described in the section of the summary of the invention, the technical features in the modification, or the above In order to achieve a part or all of the effect of (1), it is possible to appropriately replace or combine. If the technical features are not described as essential in this specification, they can be deleted as appropriate.

Claims

A sensor module (100),
A magnetic sensor (60) in which a plurality of detection elements (61, 62) whose characteristics change according to the direction of the magnetic field are respectively arranged at different rotation angle positions with respect to the detected object (15) rotating in the direction of the magnetic field;
A temperature specifying unit (85) for specifying the ambient temperature of the magnetic sensor,
A fixing member (40) for fixing the magnetic sensor,
A correction information storage section (81, for storing correction information prepared in advance for each detection element corresponding to a temperature error that may occur in each of the plurality of detection elements of the magnetic sensor fixed by the fixing member). 82),
A correction calculation unit (71, 72) for individually correcting the signal output from each of the detection elements by referring to the correction information according to the specified environmental temperature;
An angle calculation unit (80) that obtains and outputs a detection value corresponding to the rotation angle of the detected object using the corrected signal,
A sensor module including.
The sensor module according to claim 1, wherein
A sensor module in which the magnetic sensor is sealed with a resin as a fixing material or a potting agent.
The sensor module according to claim 1 or 2, wherein
Two detection elements of the plurality of detection elements are arranged so as to be displaced by a predetermined angle within 360 degrees with respect to the magnetic field that changes due to rotation of the detected object,
The correction calculation unit refers to the correction information according to the specified environmental temperature, and determines 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 3, wherein the two detection elements are arranged at positions orthogonal to each other, and the phase difference is 90 degrees.
The sensor module according to any one of claims 1 to 4, wherein:
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 a stress generated in the magnetic sensor due to the environmental temperature by fixing with the fixing material. ..
The sensor module according to any one of claims 1 to 5, wherein:
In the sensor module, the individual correction performed by the correction calculation unit on the signal output from each of the detection elements is a correction using a higher-order function of quadratic or higher with the environmental temperature as a variable.
The sensor module according to claim 6, wherein
The correction information storage unit stores the coefficient of the higher-order function for each of the detection elements,
A sensor module in which the correction calculation unit performs the correction by the higher-order function using the coefficient stored in the correction information storage unit for each of the detection elements.
The sensor module according to any one of claims 1 to 7, wherein:
A sensor module in which the magnetic sensor is provided in a non-contact manner with an object to be detected that is rotationally driven by an actuator (19) used in any one of an intake air amount control device, an exhaust gas recirculation device, and a supercharger.
The sensor module according to any one of claims 1 to 8, wherein:
The sensor module, wherein the detection element is a Hall element or an MR element.
A sensor module (200),
A detector element (161) whose characteristics change according to the direction of the magnetic field, wherein the detector element with a temperature compensation circuit, which incorporates a circuit (163) for compensating an error due to the temperature of the detector element by the detector element, is used. A magnetic sensor (160) arranged with respect to the object to be rotated,
A fixing material for fixing the magnetic sensor,
An environmental temperature sensor (185) for specifying the environmental temperature of the magnetic sensor;
A correction information storage unit (181) for storing correction information prepared in advance corresponding to a temperature error that may occur in the magnetic sensor due to being fixed by the fixing member;
A calculation for correcting the signal output from the detection element with the temperature compensation circuit by referring to the correction information according to the specified environmental temperature and outputting a detection value corresponding to the rotation angle of the detected object. Part (180)
A sensor module including.
A temperature compensation method for detecting a rotation angle using a magnetic sensor,
A plurality of detection elements built in the magnetic sensor, the characteristics of which change depending on the direction of the magnetic field, are arranged at different rotation angle positions with respect to the detected object rotating in the direction of the magnetic field.
Fixing the magnetic sensor using a fixing material,
Specify the ambient temperature of the magnetic sensor,
Corresponding to a temperature error that may occur in each of the plurality of detection elements of the magnetic sensor fixed by the fixing member, pre-store information for correction for each detection element,
By referring to the correction information in accordance with the specified environmental temperature, the signals output from the detection elements are individually corrected, and then a detection value corresponding to the rotation angle of the detected object is obtained and output. A temperature compensation method for rotation angle detection using a magnetic sensor.