WO2021220574A1 - Sensor module - Google Patents

Abstract

Provided is a sensor module capable of reducing the effects on the sensitivity of the sensor module caused by a displacement in mounting angle of the sensor module from the mounting reference position thereof. A sensor module (1) comprises a support member (6), an angular velocity sensor (2), an inclination sensor (3), and a control unit (4). The angular velocity sensor (2) is mounted on the support member (6) and detects angular velocity. The inclination sensor (3) detects the inclination of the angular velocity sensor (2). The control unit (4) is capable of communication with the angular velocity sensor (2) and the inclination sensor (3). The control unit (4) outputs an angular velocity signal and an inclination signal. The angular velocity signal is based on a detection result which is output from the angular velocity sensor, and on alignment data which pertains to the displacement of the angular velocity sensor (2) from a reference position with respect to the support member (6). The inclination signal includes a detection result output from the inclination sensor (3).

Description

Sensor module

The present disclosure relates to a sensor module in general, and more particularly to a sensor module including a sensor and a support member for supporting the sensor.

Conventionally, a capacitive bulk ultrasonic disc gyroscope is known (see Patent Document 1). The capacitive bulk ultrasonic disk gyroscope (angular velocity sensor) of Patent Document 1 is formed by semiconductor micromachining technology and detects the angular velocity by detecting the physical quantity related to the Coriolis force generated in the bulk ultrasonic vibrating object. do.

On the other hand, when mounting the above-mentioned angular velocity sensor (gyroscope) on the support board, mounting errors may be included. That is, the sensor module to which the angular velocity sensor is attached may not be able to utilize the sufficient performance of the high-performance angular velocity sensor because it includes an error due to the attachment with respect to the original mounting position and mounting angle of the angular velocity sensor. In particular, if the mounting angle of the angular velocity sensor deviates from the reference position, the sensitivity of the sensor module decreases.

Japanese Unexamined Patent Publication No. 2009-531707

The present disclosure has been made in view of the above problems, and an object of the present disclosure is to provide a sensor module capable of suppressing the influence of the deviation amount of the mounting angle of the sensor module from the mounting reference position on the sensitivity of the sensor module.

The sensor module according to one aspect of the present disclosure includes a support member, an angular velocity sensor, an inclination sensor, and a control unit. The angular velocity sensor is mounted on the support member and detects the angular velocity. The tilt sensor detects the tilt of the angular velocity sensor. The control unit can communicate with the angular velocity sensor and the tilt sensor. The control unit outputs an angular velocity signal and a tilt signal. The angular velocity signal is a signal based on the detection result output from the angular velocity signal and the alignment data regarding the amount of deviation of the angular velocity sensor from the reference position with respect to the support member. The tilt signal includes a detection result output from the tilt sensor.

FIG. 1 is a schematic view of an angular velocity sensor of a sensor module according to an embodiment. FIG. 2 is an external view of the angular velocity sensor of the same sensor module. FIG. 3 is a cross-sectional view of X1-X1 of the angular velocity sensor of the same sensor module. FIG. 4A is a diagram illustrating the operating principle of the angular velocity sensor. FIG. 4B is a diagram illustrating the operating principle of the angular velocity sensor. FIG. 5 is a diagram showing a configuration of a sensor module according to an embodiment. FIG. 6 is a diagram for explaining the mounting inclination of the sensor module of the same. FIG. 7A is a diagram illustrating the sensitivity of the other axis of the sensor module of the same. FIG. 7B is a diagram illustrating a method of correcting the sensor sensitivity of the sensor module.

Each embodiment and modification described below is merely an example of the present disclosure, and the present disclosure is not limited to the embodiment and modification. Even if it is not the embodiment and the modified example, various changes can be made according to the design and the like as long as it does not deviate from the technical idea according to the present disclosure. Further, the direction opposite to the gravitational acceleration is defined as the + Z-axis direction, and the plane perpendicular to the Z-axis is defined as the XY plane. The X-axis and the Y-axis are orthogonal, the X-axis and the Z-axis are orthogonal, and the Y-axis and the Z-axis are orthogonal. In FIGS. 1 to 4B, FIGS. 6 and 7, the X-axis, Y-axis, and Z-axis are clearly shown.

(Embodiment)
Hereinafter, the sensor module 1 according to the present embodiment will be described with reference to FIGS. 1 to 7B.

(1) Outline As shown in FIG. 6, the sensor module 1 according to the present embodiment includes an angular velocity sensor 2, an inclination sensor 3, a control unit 4, a memory 5, and a support member 6.

The sensor module 1 converts physical quantities such as rotation angular velocity, rotation angle, and angular velocity into electrical signals, for example. That is, the sensor module 1 of the present embodiment functions as a transducer that converts a physical quantity into an electric signal. The sensor module 1 is used for various devices such as home appliances, mobile terminals, cameras, wearable terminals, game machines, vehicles (including automobiles and two-wheeled vehicles), drones, and moving objects such as aircraft or ships. Be done. In this embodiment, an in-vehicle sensor module is assumed, but it is not intended to be limited to an in-vehicle sensor module.

The angular velocity sensor 2 is also called a gyro sensor, and in the present embodiment, the angular velocity sensor 2 detects the angular velocity of the sensor module 1. As shown in FIGS. 1 to 3, the angular velocity sensor 2 is an angular velocity sensor having a structure utilizing BAW (Bulk Acoustic Wave) vibration, and is superior in noise and bias stability, and has a high Q value. Here, the bias stability is an angle error accumulated per hour. For example, the angular velocity sensor 2 according to the present embodiment is suitable when relatively high-precision angular velocity detection is required as in the automatic driving technology of a vehicle. However, the angular velocity sensor 2 according to the present embodiment can be adopted even when high-precision angular velocity detection is not required.

In the present embodiment, the angular velocity sensor 2 is, for example, a uniaxial angular velocity sensor in the Z-axis direction, and is also called 1DOF (Degree of Freedom). The angular velocity sensor 2 detects the angular velocity of the sensor module 1.

As shown in FIG. 6, the angular velocity sensor 2 is mounted on the support member 6. The mounting deviation of the angular velocity sensor 2 with respect to the control unit 4 with respect to the control unit 4, that is, the alignment information is acquired in the manufacturing process of the sensor module 1. Here, the mounting deviation is defined as the difference between the mounted inclination of the angular velocity sensor 2 and the originally mounted reference position with reference to the control unit 4.

The tilt sensor 3 includes an acceleration sensor 30 in this embodiment. The acceleration sensor 30 is a sensor that measures acceleration, tilt, impact, vibration, and the like. In this embodiment, the acceleration sensor 30 is a low gravity acceleration type MEMS (Micro Electro Mechanical Systems) sensor. The low gravitational acceleration type used in this embodiment includes a capacitance method, a piezo resistance method, a heat detection method, and the like. The acceleration sensor 30 may be a PZT (abbreviation of lead titanium zirconate (Pb (Zr, Ti) O ₃ )) acceleration sensor or the like, in addition to the MEMS sensor.

In the present embodiment, the control unit 4 includes an ASIC (Application specific integrated circuit) that is connected to the angular velocity sensor 2 and the tilt sensor 3 and converts signals from various sensors into electrical signals.

(2) Configuration The detailed configuration of the sensor module 1 according to the present embodiment will be described below with reference to FIGS. 1 to 7B.

In the present embodiment, as shown in FIG. 6, the sensor module 1 includes an angular velocity sensor 2, an inclination sensor 3, a control unit 4, a memory 5, and a support member 6. Further, as shown in FIGS. 2 and 3, the sensor module 1 further includes a pedestal 9, a bonding wire 10, a case 11, and an auxiliary member 12.

As shown in FIG. 1, the angular velocity sensor 2 is an angular velocity sensor having a structure utilizing BAW vibration. As shown in FIG. 1, the angular velocity sensor 2 according to the present embodiment includes a bulk ultrasonic resonance element 7 and a substrate 8. The bulk ultrasonic resonance element 7 includes a movable portion 71, a plurality of (eight in FIG. 1) electrodes 72, and a polycrystalline silicon wiring 74. The movable portion 71 is, for example, a resonance element and is formed in a disk shape (disk shape) having a circular shape in a plan view in the Z-axis direction. Here, the movable portion 71 is a non-piezoelectric material such as single crystal or polycrystalline silicon, and does not need to be made of a piezoelectric material. The moving portion 71 may be made of a semiconductor or metal material such as silicon carbide, gallium nitride, aluminum nitride or quartz.

The plurality of electrodes 72 are arranged at equal intervals around the disk-shaped movable portion 71. The bulk ultrasonic resonance element 7 has a capacitive gap 73 between each electrode 72 and the movable portion 71. The plurality of electrodes 72 include a plurality of (here, four) driving electrodes 721 and a plurality of (here, four) detection electrodes 722. A constant capacitance is generated between the plurality of electrodes 72 and the movable portion 71.

In a state where a drive signal is applied to each drive electrode 721 to vibrate the movable portion 71 at a constant speed, a Coriolis force is generated according to the angular velocity applied to the movable portion 71. When the Coriolis force is generated, the constant capacitance changes. The bulk ultrasonic resonance element 7 detects the angular velocity by detecting the change in capacitance at the detection electrode 722.

The operation of the bulk ultrasonic resonance element 7 will be described with reference to FIGS. 4A and 4B. 4A and 4B are conceptual diagrams for explaining the operating principle of the bulk ultrasonic resonance element 7.

In the present embodiment, as an example, the bulk ultrasonic resonance element 7 is a high frequency (MHz band) driven capacitive bulk ultrasonic gyroscope.

As shown in FIG. 4A, the movable portion 71 vibrates due to the Coriolis force so as to repeatedly expand and contract in two directions (X-axis direction and Y-axis direction) orthogonal to each other on a plane orthogonal to the central axis thereof. do. The bulk ultrasonic resonance element 7 outputs the amount of deformation (movement amount) of the movable portion 71 as an electric signal. That is, as shown in FIG. 4B, the amount of deformation of the movable portion 71 appears as a change in the capacitance between the movable portion 71 and the detection electrode 722, so that the bulk ultrasonic resonance element 7 has this capacitance. Outputs an electrical signal according to the change in.

The bulk ultrasonic resonance element 7 is an element that outputs an electric signal according to the physical quantity to be detected. In the present embodiment, since the detection target is the angular velocity around the Z axis, the bulk ultrasonic resonance element 7 outputs an electric signal corresponding to the angular velocity around the Z axis.

In the bulk ultrasonic resonance element 7, the central portion of the movable portion 71 and one of the plurality of drive electrodes 721, the drive electrode 721, are connected by the polycrystalline silicon wiring 74. The polycrystalline silicon wiring 74 supplies a DC bias to the movable portion 71.

As shown in FIGS. 1 and 3, the substrate 8 is formed on a flat plate and has a thickness in the Z-axis direction.

The element surface 81 of the substrate 8 faces the bulk ultrasonic resonance element 7 in the Z-axis direction. That is, the bulk ultrasonic resonance element 7 is arranged on the element surface 81 side of the substrate 8. Here, the insulating layer 14 may be patterned on the element surface 81 of the substrate 8. That is, the bulk ultrasonic resonance element 7 may be provided with an insulating layer 14 between the bulk ultrasonic resonance element 7 and the element surface 81. In the present embodiment, the insulating layer 14 is provided between the bulk ultrasonic resonance element 7 and the element surface 81. In the present embodiment, as an example, the substrate 8 has a substantially circular shape (disk shape) in a plan view in the Z-axis direction like the bulk ultrasonic resonance element 7 shown in FIG. The substrate 8 is, for example, a silicon substrate.

In the present embodiment, the support member 6 has a substantially square shape in a plan view as an example. Here, the support member 6 is an ASIC package. That is, the support member 6 has a configuration in which the processing circuit 62 is built as a semiconductor chip in a package such as a resin package having electrical insulation. Therefore, the bulk ultrasonic resonance element 7 is mounted on one surface (support surface 61) of the support member 6 as an ASIC package.

The bulk ultrasonic resonance element 7 is fixed to the support surface 61 of the support member 6. The term "fixed" as used in the present disclosure means that the state is kept in a fixed position by various means. That is, it means that the bulk ultrasonic resonance element 7 is in a state of not moving with respect to the support surface 61 of the support member 6.

As a means for fixing the bulk ultrasonic resonance element 7 to the support surface 61 of the support member 6, for example, an appropriate means such as adhesion, adhesion, brazing, welding or crimping can be adopted. In the present embodiment, as an example, the means for fixing the bulk ultrasonic resonance element 7 to the support surface 51 is adhesion with a silicone-based adhesive. The support member 6 is formed to be one size larger than the angular velocity sensor 2, and the bulk ultrasonic resonance element 7 is fixed to the central portion of the support surface 51.

In this embodiment, the pedestal 9 is, for example, ceramic. As shown in FIG. 3, the pedestal 9 fixes the support member 6 on the upper side of the pedestal 9, and the support member 6 fixes the bulk ultrasonic resonance element 7. In the present embodiment, the sensor module 1 has a structure in which the bulk ultrasonic resonance element 7 is laminated on the substrate 8 and the electrode surface of the bulk ultrasonic resonance element 7 integrated with the substrate 8 is fixed to the pedestal 9, so-called. It has a face-down structure. The pedestal 9 is a mounting substrate, and the support member 6 and the pedestal 9 are electrically connected by a bonding wire 10 as shown in FIG.

As shown in FIGS. 2 and 3, the case 11 has a case main body 111 and a flange portion 112. FIG. 2 is an external view of the sensor module 1, and FIG. 3 is a cross-sectional view taken along the line X1-X1 of FIG. The case body 111 has a rounded (R) shape with curved corners. The flange portion 112 is a portion protruding outward from the outer peripheral edge of the case body 111. In the case 11, as a means for fixing the flange portion 112 to the pedestal 9, for example, an appropriate means such as adhesion, adhesion, brazing, welding or crimping can be adopted. In the present embodiment, as an example, the fixing means between the pedestal 9 and the case 11 is adhesive.

Here, in the present embodiment, the case 11 is airtightly coupled to the pedestal 9, so that an airtight space is formed between the case 11 and the pedestal 9. Therefore, the bulk ultrasonic resonance element 7 and the like are housed in the airtight space, and it is possible to suppress the influence of humidity and the like on the sensor module 1.

The auxiliary member 12 is provided with the auxiliary member 12 on the lower side of the pedestal 9 in FIG. The auxiliary member 12 is made by molding a plurality of wirings with resin, and functions as an electrode routing and a cushioning material for the sensor module 1.

As shown in FIG. 3, the sensor module 1 according to the present embodiment has a processing circuit 62. The processing circuit 62 is provided in the ASIC as the support member 6 in the present embodiment. The processing circuit 62 executes processing related to the electric signal output from the bulk ultrasonic resonance element 7. In the present embodiment, the control unit 4 is provided on the support member 6. In other words, the support member 6 includes a processing circuit 62 that executes processing related to an electric signal output from the bulk ultrasonic resonance element 7.

In the present embodiment, the processing circuit 62 converts an analog electric signal (analog signal) output from the bulk ultrasonic resonance element 7 into a digital signal. The processing circuit 62 executes appropriate processing such as noise removal and temperature compensation. Further, the processing circuit 62 gives a drive signal for driving the bulk ultrasonic resonance element 7 to the bulk ultrasonic resonance element 7.

Further, the processing circuit 62 may execute arithmetic processing such as integration processing or differentiation processing, for example. For example, the processing circuit 62 executes integration processing on the electric signal output from the bulk ultrasonic resonance element 7, and the sensor module 1 obtains the integrated value of the angular velocity around the Z axis, that is, the angular velocity around the Z axis. It is possible. On the other hand, for example, when the processing circuit 62 executes the differential processing on the electric signal output from the bulk ultrasonic resonance element 7, the sensor module 1 has the differential value of the angular velocity around the Z axis, that is, the angle around the Z axis. It is possible to obtain the acceleration.

The angular velocity sensor 2 is installed on the support surface 61 of the support member 6. Depending on the mounting accuracy at this time, mounting deviation with respect to the control unit 4 occurs.

The tilt sensor 3 includes a so-called acceleration sensor 30 in this embodiment. The acceleration sensor 30 includes a first sensor 31, a second sensor 32, and a third sensor 33. The first sensor 31 detects the acceleration of the first axis (here, the X axis). The second sensor 32 detects the acceleration of the second axis (here, the Y axis) orthogonal to the first axis X. The third sensor 33 detects the acceleration of the third axis (here, the Z axis) orthogonal to the first axis X and the second axis Y. That is, the acceleration sensor 30 is a three-axis acceleration sensor.

The acceleration sensor 30 is a MEMS chip using MEMS technology in this embodiment. Compared with the case where the X-axis, Y-axis, and Z-axis sensors are separately provided, the acceleration sensor 30 is configured as a MEMS chip having a monolithic structure, so that the orthogonality of the three axes is higher. In this embodiment, the tilt sensor 3 has a monolithic structure.

The sensor module 1 further includes a 3-axis angular velocity sensor 37. The 3-axis angular velocity sensor 37 has a fourth sensor 34, a fifth sensor 35, and a sixth sensor 36. The fourth sensor 34 detects the angular velocity of the first axis, that is, the X axis. The fifth sensor 35 detects the angular velocity of the second axis, that is, the Y axis. The sixth sensor 36 detects the angular velocity of the third axis, that is, the Z axis. The fourth sensor 34, the fifth sensor 35, and the sixth sensor 36 are 3-axis angular velocity sensors composed of one chip in the present embodiment. That is, the 3-axis angular velocity sensor 37 includes a 3-axis angular velocity sensor in which the 4th sensor 34, the 5th sensor 35, and the 6th sensor 36 are integrated into one chip.

In the present embodiment, the tilt sensor 3 includes a 3-axis angular velocity sensor 37 and a 3-axis acceleration sensor 30, and the 3-axis angular velocity sensor 37 and the 3-axis acceleration sensor 30 are configured by one chip. That is, the tilt sensor 3 is a 6-axis inertial sensor including a 3-axis acceleration sensor 30 and a 3-axis angular velocity sensor 37. By realizing the 3-axis acceleration sensor 30 and the 3-axis angular velocity sensor 37 on a single chip, the 6-axis high orthogonality is higher than when the 3-axis acceleration sensor 30 and the 3-axis angular velocity sensor 37 are separately provided. Has sex.

The tilt sensor 3 is installed on the support surface 61 of the support member 6. Depending on the mounting accuracy at this time, mounting deviation with respect to the control unit 4 occurs.

The memory 5 is composed of a device selected from ROM (Read Only Memory), RAM (Random Access Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), and the like.

The memory 5 stores alignment data regarding the amount of deviation of the angular velocity sensor 2 from the reference position with respect to the support member 6. Here, in the sensor module 1, as shown in FIG. 6, the rotation axis C is defined as the detection axis of the sensor module 1. The sensor module 1 is installed so that the rotation axis C is perpendicular to the horizontal plane 64. On the other hand, the detection axis D is also defined in the angular velocity sensor 2. Each angular velocity sensor 2 is installed on the support member 6 so that the detection axis D of the angular velocity sensor 2 is perpendicular to the support member 6. When the angular velocity sensor 2 is attached to the support member 6, there is a possibility that the rotation axis C and the detection axis D do not match because there is an alignment error due to the attachment accuracy. Here, the position where the rotation axis C and the detection axis D coincide with each other is set as the reference position.

The control unit 4 is set to be able to communicate with the angular velocity sensor 2 and the tilt sensor 3. Further, the control unit 4 is set so as to be able to communicate with the memory 5. The control unit 4 is installed on the support member 6 in the present embodiment. The attitude information of the control unit 4 with respect to the gravitational acceleration is grasped in the manufacturing process of the sensor module 1. Here, the posture information is information on the installation state of the control unit 4 with respect to the gravitational acceleration, and is information on alignment.

Finally, for in-vehicle use, there is a possibility that mounting misalignment will occur when the sensor module 1 is installed. In the present embodiment, the angle formed by the second surface 63 of the support member 6 and the horizontal plane 64 is set to the alignment deviation amount θ as shown in FIG.

(3) Outline of Operation The control unit 4 is connected to the angular velocity sensor 2 and the tilt sensor 3 and converts the signals of the angular velocity sensor 2 and the tilt sensor 3 into electrical signals. For example, the control unit 4 converts the capacitance change of the MEMS detected by the acceleration sensor 30 into an electric signal (voltage).

The control unit 4 is set so that it can be connected to the memory 5.

The control unit 4 outputs an angular velocity signal and a tilt signal. The angular velocity signal is a signal based on the detection result output from the angular velocity sensor 2 and the alignment data regarding the amount of deviation of the angular velocity sensor 2 from the reference position with respect to the support member 6. The tilt signal includes the detection result output from the tilt sensor 3.

Alignment data is acquired in advance with the angular velocity sensor 2 and the tilt sensor 3 mounted on the support member 6.

The control unit 4 corrects the detection result of the angular velocity sensor 2 based on the detection result of the tilt sensor 3. The gradient signal includes a first signal, a second signal, and a third signal. Here, the first signal is a signal based on the detection result of the first sensor that detects the acceleration of the first axis. The second signal is a signal based on the detection result of the second sensor that detects the acceleration of the second axis. The third signal is a signal based on the detection result of the third sensor that detects the acceleration of the third axis. More specifically, the first signal is a signal representing acceleration in the first axis. The second signal is a signal representing acceleration in the second axis. The third signal is a signal representing acceleration in the third axis. The first signal, the second signal, and the third signal are signals used for obtaining the inclination of the angular velocity sensor 2 and for correcting the detection result of the angular velocity sensor 2.

Specifically, the control unit 4 shifts the axis for detecting the angular velocity of the angular velocity sensor 2 based on the first signal, the second signal, and the third signal included in the tilt signal and the alignment data stored in the memory 5. Detect the quantity θ. The control unit 4 corrects the detection result of the angular velocity sensor 2 using the deviation amount θ, and outputs the corrected detection result as an angular velocity signal. Further, the control unit 4 outputs the output of the tilt sensor together with the angular velocity signal.

The control unit 4 corrects the signal of the angular velocity sensor 2 by using the detection result of the 3-axis angular velocity sensor 37 included in the tilt sensor 3. Specifically, the outputs from the 4th sensor, the 5th sensor, and the 6th sensor are the 4th signal, the 5th signal, and the 6th signal. Here, the fourth signal is a signal based on the detection result of the fourth sensor that detects the angular velocity of the first axis. The fifth signal is a signal based on the detection result of the fifth sensor that detects the angular velocity of the second axis. The sixth signal is a signal based on the detection result of the sixth sensor that detects the angular velocity of the third axis. More specifically, the fourth signal is a signal representing acceleration in the first axis. The fifth signal is a signal representing acceleration in the second axis. The sixth signal is a signal representing acceleration in the third axis. The rotation axis C, which is the original detection axis of the angular velocity sensor 2, and the Z axis, which is the third axis, coincide with each other. The rotation component of the three-dimensional space of the angular velocity sensor 2 is output as a fourth signal, a fifth signal, and a sixth signal by the three-axis angular velocity sensor 37. Since the sixth signal and the output of the angular velocity sensor 2 should match, it can be used for confirming and correcting the detection result of the angular velocity sensor 2. Further, since the fourth signal and the fifth signal are components that are not originally detected, they can be corrected by introducing an offset so as to cancel the fourth signal and the fifth signal. As described above, the control unit 4 corrects the signal of the angular velocity sensor 2 by using the signal of the three-axis angular velocity sensor 37.

(4) Correction Method A correction method for the sensor module 1 of the present embodiment will be described.

The sensor module 1 can grasp the attitude information of the control unit 4 with respect to the gravitational acceleration in the manufacturing process of the sensor module 1. In other words, in the manufacturing process of the sensor module 1, the inclination due to mounting when the control unit 4 is attached to the support member 6 is grasped.

The method of grasping the alignment information of the tilt sensor 3 will be described. In the present embodiment, the tilt sensor 3 includes a 3-axis acceleration sensor 30 and a 3-axis angular velocity sensor 37. When the tilt sensor 3 is attached to the support member 6 in the manufacturing process of the sensor module 1, the attitude information of the 3-axis accelerometer 30 with respect to the control unit 4 of the 3-axis accelerometer 30 is output from the 3-axis accelerometer 30. Can be grasped by. The posture information means the mounting accuracy to the mounting target and the mounting state. For example, here, the output of the 3-axis accelerometer is the attitude information of the 3-axis accelerometer 30 with respect to the control unit 4.

The control unit 4 stores the obtained attitude information of the acceleration of the three axes in the memory 5.

Next, a method of grasping the alignment information of the angular velocity sensor 2 will be described. As described above, the angular velocity sensor 2 is a uniaxial angular velocity sensor (1DOF). The angular velocity sensor 2 is mounted on the support member 6. In the manufacturing process of the sensor module 1, the angular velocity sensor 2 is mounted, and the control unit 4 acquires the sensitivity output when the attitude information with respect to the gravitational acceleration of the control unit 4 is changed at some points. Specifically, the control unit 4 acquires the outputs of the angular velocity sensor 2 at various angles and searches for the portion having the highest sensitivity. As shown in FIG. 6, the sensitivity of the angular velocity sensor 2 is maximized at the point where the rotation axis C and the detection axis D coincide with each other. The control unit 4 changes the measurement axis for each point to be measured. By measuring several points, the control unit 4 can estimate which point will be the maximum output of the angular velocity sensor 2.

The control unit 4 stores the posture information regarding the maximum point in the memory 5.

Explain the mounting error when mounted on a vehicle. The mounting error of the sensor module 1 when mounted on a vehicle may have a tilt with respect to the gravitational acceleration depending on, for example, the tilt of the mounting location, the tightening method of the screws, and the like. Therefore, the amount of alignment error in the actual mounting of the sensor module 1 is absolutely determined from the information (detection result) of the 3-axis acceleration sensor 30 and the alignment information already stored in the memory 5. The slope as a value can be calculated. For example, if you have an output database of the 3-axis accelerometer 30, you can tell how many times it is tilted just by looking at the output of the 3-axis accelerometer. Similarly, even if the mounting is tilted several times, the tilt of the mounting can be found only by looking at the output of the 3-axis accelerometer 30. When the deviation amount θ is found, the angular velocity sensor 2 may be corrected accordingly. The 3-axis angular velocity sensor 37 supplements the 3-axis acceleration sensor and can be used for verification. By detecting the detected result of the corrected angular velocity sensor 2 with the 3-axis angular velocity sensor 37, the corrected angular velocity sensor 2 can be checked.

In this embodiment, the true inclination of the support member 6 with respect to the gravitational acceleration and the output of the three-axis acceleration sensor 30 are correlated. If there is a correlation, the inclination of the support member 6 can be determined from the output of the three-axis acceleration sensor 30. Similarly, even in the mounted sensor module 1, the inclination of the sensor module 1 can be found by looking at the output of the three-axis acceleration sensor 30. Therefore, if the misalignment amount of the sensor module 1 is known, the control unit 4 can correct the angular velocity sensor 2 from the offset amount at the time of mounting on the vehicle. That is, the alignment can be adjusted again after being mounted on the car.

Assuming that the measurement sensitivity is Sa, the corrected sensitivity is Si, and the alignment error is θ, cos θ is represented by Equation 1, so the corrected sensitivity Si is represented by Equation 2 below. Note that | Sa | and | Si | represent the absolute values of Sa and Si, respectively.

That is, the corrected sensitivity Si can be calculated from the alignment deviation amount θ and the measurement sensitivity Sa.

Sensitivity is correctly output in order to perform sensitivity correction for other axes that performs sensitivity correction based on angle information. Here, assuming that the sensor sensitivity is S and the components of the X-axis, Y-axis, and Z-axis are Sx, Sy, and Sz, respectively, the Z-axis other-axis sensitivity Sensor is represented by the following equation 3.

(5) Advantages The sensor module 1 includes a support member 6, an angular velocity sensor 2, an inclination sensor 3, and a control unit 4. The angular velocity sensor 2 is mounted on the support member 6 and detects the angular velocity. The tilt sensor 3 detects the tilt of the angular velocity sensor 2. The control unit 4 can communicate with the angular velocity sensor 2 and the tilt sensor 3. The control unit 4 outputs an angular velocity signal and a tilt signal. The angular velocity signal is a signal based on the detection result output from the angular velocity sensor and the alignment data regarding the amount of deviation of the angular velocity sensor 2 from the reference position with respect to the support member 6. The tilt signal includes the detection result output from the tilt sensor 3.

According to this configuration, it is possible to provide the sensor module 1 capable of correcting the sensitivity of the angular velocity sensor module.

With the sensor module 1 mounted, the alignment error of the sensor module 1 can be corrected.

(6) Modified Examples The modified examples are listed below. The modifications described below can be applied in combination with the above embodiments as appropriate.

The tilt sensor 3 is configured to be an acceleration sensor using MEMS, but is not limited to this configuration. For example, the tilt sensor 3 may be composed of a mercury switch.

The 3-axis acceleration sensor 30 has a configuration using MEMS, but is not limited to this configuration. As the 3-axis accelerometer 30, three 1-axis accelerometers using MEMS may be used, or three non-MEMS type accelerometers may be used. For example, the 3-axis acceleration sensor 30 may use a piezo resistance type semiconductor type acceleration sensor.

The control unit 4 is configured to correct the detection result of the angular velocity sensor 2 by using the signal from the 3-axis angular velocity sensor 37, but the configuration is not limited to this. If the detection result of the corrected angular velocity sensor 2 is appropriate, the control unit 4 may output the corrected detection result as an angular velocity signal. That is, the 3-axis angular velocity sensor 37 of the tilt sensor 3 may check the angular velocity signal corrected by the control unit 4. Specifically, the control unit 4 corrects the angular velocity sensor 2 from the inclination of the angular velocity sensor 2 detected by the three-axis acceleration sensor 30. By comparing the corrected result of the angular velocity sensor 2 with the detection result of the three-axis angular velocity sensor 37, the control unit 4 can check whether the detection result of the angular velocity sensor 2 is correctly corrected.

In the embodiment, the three-axis acceleration sensor 30 and the three-axis angular velocity sensor 37 are used to correct the detection result of the angular velocity sensor 2, but the configuration is not limited to this. The detection result of the angular velocity sensor 2 may be corrected by the three-axis acceleration sensor 30 without using the three-axis angular velocity sensor 37.

The bulk ultrasonic resonance element 7 has a face-down element structure, but is not limited to this configuration. The bulk ultrasonic resonance element 7 may have a face-up element structure.

The bulk ultrasonic resonance element 7 is not limited to the element using the MEMS technology, and may be another element.

The fact that the support member 6 is an ASIC package including the processing circuit 62 is not an essential configuration for the sensor module 1, and an appropriate configuration can be adopted for the support member 6. That is, the support member 6 does not have to be a member including an electronic component, and may be a simple structure such as a plate material. Further, the shape and material of the support member 6 are not limited to the examples shown in the embodiment. For example, the support member 6 may have a rectangular shape, a circular shape, or the like in a plan view. Further, the support member 6 may be, for example, a member made of resin, silicon, ceramic, or the like.

The control unit 4 and the support member 6 are configured to include a separate ASIC, but the configuration is not limited to this. The control unit 4 and the support member 6 may be configured to include the same ASIC. That is, the ASIC package as the support member 6 may be a circuit including the control unit 4 and the processing circuit 62.

The memory 5 may be configured to be removable from the sensor module 1.

The memory 5 is not an essential configuration for the sensor module 1, and the memory 5 does not have to be mounted on the sensor module 1. It suffices if it is configured so that it can be connected to an external storage device. For example, the sensor module 1 has only a QR code (Quick Reference Code) (registered trademark), and the alignment information of the sensor module 1 may be stored in the cloud.

The bulk ultrasonic resonance element 7 is not limited to one physical quantity, and may be configured to detect a plurality of physical quantities. For example, the bulk ultrasonic resonance element 7 may detect the angular velocity and the acceleration.

(summary)
As described above, the sensor module (1) of the first aspect includes a support member (6), an angular velocity sensor (2), an inclination sensor (3), and a control unit (4). The angular velocity sensor (2) is mounted on the support member (6) and detects the angular velocity. The tilt sensor (3) detects the tilt of the angular velocity sensor (2). The control unit (4) can communicate with the angular velocity sensor (2) and the tilt sensor (3). The control unit (4) outputs an angular velocity signal and a tilt signal. The angular velocity signal is a signal based on the detection result output from the angular velocity sensor and the alignment data regarding the amount of deviation of the angular velocity sensor (2) from the reference position with respect to the support member (6). The tilt signal includes the detection result output from the tilt sensor (3).

According to this configuration, it is possible to provide the sensor module (1) capable of suppressing the influence of the deviation amount (θ) of the mounting angle of the sensor module (1) from the mounting reference position on the sensitivity of the sensor module. Further, it is possible to provide a sensor module (1) capable of correcting the sensitivity of the sensor module (1) including the angular velocity sensor (2) even after mounting the sensor module (1).

In the sensor module (1) of the second aspect, in the first aspect, the tilt sensor (3) includes an acceleration sensor (30).

According to this configuration, the tilt sensor (3) can detect the tilt with high accuracy by including the acceleration sensor (30).

In the sensor module (1) of the third aspect, in the first or second aspect, the tilt sensor (3) is the first sensor (31), the second sensor (32), and the third sensor (33). And, including. The first sensor (31) detects the acceleration of the first axis (X). The second sensor (32) detects the acceleration of the second axis (Y) orthogonal to the first axis (X). The third sensor (33) detects the acceleration of the third axis orthogonal to the first axis (X) and the second axis (Y). The control unit (4) corrects the detection result of the angular velocity sensor (2) based on the detection result of the tilt sensor (3).

According to this configuration, the accuracy of the correction of the angular velocity sensor (2) can be improved by using the 3-axis acceleration sensor (30).

In the sensor module (1) of the fourth aspect, in the third aspect, the tilt signal includes a first signal, a second signal, and a third signal. The first signal is based on the detection result of the first sensor (31). The second signal is based on the detection result of the second sensor (32). The third signal is based on the detection result of the third sensor (33). The control unit (4) detects the amount of deviation (θ) of the axis that detects the angular velocity of the angular velocity sensor (2) based on the first signal, the second signal, the third signal, and the alignment data. , The detection result of the angular velocity sensor (2) is corrected using the deviation amount (θ), and the corrected detection result is output as an angular velocity signal.

According to this configuration, the control unit 4 determines the amount of axial deviation (θ) for detecting the angular velocity of the angular velocity sensor (2) based on the first signal, the second signal, the third signal, and the alignment data. Highly accurate correction can be performed by detecting and correcting the detection result of the angular velocity sensor (2) using the deviation amount (θ).

In the sensor module (1) of the fifth aspect, in any one of the first to fourth aspects, the tilt sensor (3) has a monolithic structure.

According to this configuration, the orthogonality of the three orthogonal axes of the tilt sensor (3) is higher than that in the case of not having a monolithic structure. Therefore, the accuracy of correcting the angular velocity sensor (2) is improved.

In the sensor module (1) of the sixth aspect, in any one of the first to fifth aspects, the alignment data is a state in which the angular velocity sensor (2) and the inclination sensor (3) are mounted on the support member (6). Obtained in advance at.

According to this configuration, alignment information can be acquired in a relatively simple configuration.

The sensor module (1) of the seventh aspect further includes a fourth sensor (34), a fifth sensor (35), and a sixth sensor (36) in the third or fourth aspect. The fourth sensor (34) detects the angular velocity with the first axis (X) as the rotation axis. The fifth sensor (35) detects the angular velocity with the second axis (Y) as the rotation axis. The sixth sensor (36) detects the angular velocity with the third axis (Z) as the rotation axis. The control unit (4) further uses the fourth sensor (34), the fifth sensor (35), and the sixth sensor (36) to correct the detection result of the angular velocity sensor (2).

According to this configuration, the accuracy of correction is improved by using the fourth sensor (34), the fifth sensor (35), and the sixth sensor (36) in addition to the angular velocity sensor (2).

In the sensor module (1) of the eighth aspect, in the seventh aspect, the control unit (4) uses the fourth sensor (34), the fifth sensor (35), and the sixth sensor (36) to perform the angular velocity. The detection result of the sensor (2) is corrected, and if the detection result of the corrected angular velocity sensor (2) is appropriate, the corrected detection result is output as an angular velocity signal.

According to this configuration, the accuracy of the correction is improved by checking the detected detection result after the correction by using the fourth sensor (34), the fifth sensor (35) and the sixth sensor (36) in a complementary manner.

The sensor module (1) of the ninth aspect further includes a memory (5) that stores alignment data and can be connected to the control unit (4) in any one of the first to eighth aspects.

According to this configuration, by storing the alignment data in advance, it is possible to correct the sensitivity of the angular velocity sensor (2) by referring to it.

1 Sensor module 2 Angle speed sensor 3 Tilt sensor 4 Control unit 5 Memory 30 Acceleration sensor 31 1st sensor 32 2nd sensor 33 3rd sensor 34 4th sensor 35 5th sensor 36 6th sensor X 1st axis Y 2nd axis Z 3rd axis θ deviation amount

Claims (9)

Support members and
An angular velocity sensor mounted on the support member to detect the angular velocity,
An inclination sensor that detects the inclination of the angular velocity sensor and
A control unit capable of communicating with the angular velocity sensor and the tilt sensor is provided.
The control unit
An angular velocity signal based on the detection result output from the angular velocity sensor and alignment data regarding the amount of deviation of the angular velocity sensor from the reference position with respect to the support member.
A tilt signal including the detection result output from the tilt sensor is output.
Sensor module. The tilt sensor includes an acceleration sensor.
The sensor module according to claim 1. The tilt sensor includes a first sensor, a second sensor, and a third sensor.
The first sensor detects the acceleration of the first axis and
The second sensor detects the acceleration of the second axis orthogonal to the first axis, and detects the acceleration.
The third sensor detects the acceleration of the first axis and the third axis orthogonal to the second axis, and detects the acceleration.
The control unit corrects the detection result of the angular velocity sensor based on the detection result of the tilt sensor.
The sensor module according to claim 1 or 2. The tilt signal is
The first signal based on the detection result of the first sensor and
The second signal based on the detection result of the second sensor and
Including a third signal based on the detection result of the third sensor,
The control unit detects the amount of deviation of the axis that detects the angular velocity of the angular velocity sensor based on the first signal, the second signal, the third signal, and the alignment data, and the deviation. The amount is used to correct the detection result of the angular velocity sensor, and the corrected detection result is output as the angular velocity signal.
The sensor module according to claim 3. The tilt sensor has a monolithic structure.
The sensor module according to any one of claims 1 to 4. The alignment data is acquired in advance in a state where the angular velocity sensor and the inclination sensor are mounted on the support member.
The sensor module according to any one of claims 1 to 5. Further equipped with a fourth sensor, a fifth sensor and a sixth sensor,
The fourth sensor detects the angular velocity with the first axis as the rotation axis, and detects the angular velocity.
The fifth sensor detects the angular velocity with the second axis as the rotation axis, and detects the angular velocity.
The sixth sensor detects the angular velocity with the third axis as the rotation axis, and detects the angular velocity.
The control unit further uses the fourth sensor, the fifth sensor, and the sixth sensor to correct the detection result of the angular velocity sensor.
The sensor module according to claim 3 or 4. The control unit uses the fourth sensor, the fifth sensor, and the sixth sensor to correct the detection result of the angular velocity sensor, and if the corrected detection result of the angular velocity sensor is appropriate, after correction. Is output as the angular velocity signal.
The sensor module according to claim 7. A memory that stores the alignment data and can be connected to the control unit is further provided.
The sensor module according to any one of claims 1 to 8.

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