Sensor module, electronic apparatus, moving object positioning device, and moving object

Abstract

The invention discloses a sensor module, an electronic apparatus, a moving object positioning device, and a moving object. A sensor module is provided with: a plurality of inertial sensor elements including: a first inertial sensor element that detects a first physical quantity; and a second inertial sensor element that detects the first physical quantity, the second inertial sensor element being different from the first inertial sensor element in type, and a plurality of inertial sensor elements each detecting the first physical quantity; and a calculation unit that uses a plurality of weighting coefficients to weight-average the detection signals of the plurality of inertial sensor elements.

Description

Technical Field

[0001] The present invention relates to a sensor module, an electronic device, a mobile object positioning device, and a mobile object. Background Art

[0002] Patent Document 1 describes a scheme in which a plurality of angular velocity sensor devices are provided and an average value of Z-axis angular velocity data from these plurality of angular velocity sensor devices is calculated by a microcontroller, thereby enabling the Z-axis angular velocity data to be more accurate.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2019-163955

[0004] As a method for using multiple angular velocity sensor devices for the purpose of achieving higher accuracy, a combination of different types of sensor devices has been studied. In this case, the effects of combining different types of sensor devices must be considered. Summary of the Invention

[0005] A sensor module according to one aspect of the present application comprises: a plurality of inertial sensor elements, including: a first inertial sensor element for detecting a first physical quantity; and a second inertial sensor element for detecting the first physical quantity, wherein the second inertial sensor element is of a different type from the first inertial sensor element, and the plurality of inertial sensors respectively detect the first physical quantity; and a calculation unit for performing a weighted average of the detection signals of the plurality of inertial sensor elements using a plurality of weight coefficients.

[0006] An electronic device according to one aspect of the present application includes the sensor module described above.

[0007] One aspect of the present application relates to a mobile object positioning device comprising: a plurality of inertial sensor elements, including a first inertial sensor element for detecting a first physical quantity; and a second inertial sensor element for detecting the first physical quantity. The plurality of inertial sensor elements are of different types from the first inertial sensor element, each detecting the first physical quantity; a calculation unit for performing a weighted average of detection signals from the plurality of inertial sensor elements using a plurality of weight coefficients; a receiving unit for receiving satellite signals superimposed with position information from positioning satellites; an acquisition unit for acquiring the position information based on the satellite signals; and a calculation unit for calculating the position of the mobile object based on the position information and the weighted average detection signal from the calculation unit.

[0008] A moving object according to one aspect of the present application includes the above-described moving object positioning device. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a block diagram of the sensor module according to the first embodiment.

[0010] Figure 2 This is a diagram illustrating the sensor coordinate system.

[0011] Figure 3 It is a perspective view showing the appearance of the sensor module.

[0012] Figure 4 This is a block diagram of the correction circuit.

[0013] Figure 5 This is a block diagram of a sensor module according to the second embodiment.

[0014] Figure 6 This is a perspective view showing an example of an electronic device according to a third embodiment.

[0015] Figure 7 This is a perspective view showing another example of the electronic device according to the third embodiment.

[0016] Figure 8 This is a block diagram of a mobile object positioning device according to a fourth embodiment.

[0017] Figure 9 This is a diagram showing the operation of the mobile object positioning device.

[0018] Description of reference numerals:

[0019] 1: Frame; 2: Box; 3: Cover; 4: Screw hole; 7: Screw; 8: Mounting surface; 10: First sensor; 20: Second sensor; 23: Third sensor; 24: Fourth sensor; 30: Arithmetic circuit; 31: Multiplication unit; 32: Multiplication unit; 33: Addition unit; 40: Correction circuit; 41, 42, 43, 44, 45, 46: Single-axis correction unit; 47: Inter-axis correction unit; 50: Data processing circuit; 60: I / F circuit; 61: Fault detection circuit; 62: Weight coefficient storage circuit; 100: Inertial measurement unit; 100a: Sensor module; 110: Smartphone; 111: Control unit; 130: Automobile; 131: Vehicle body; 132: Vehicle posture control device; 133: Wheel; 140: Tractor; 150: Arithmetic processing unit; 200: Host; 30 0: Arithmetic circuit; 311, 312, 313, 314: Switch; 321, 322, 323, 324: Multiplication unit; 331, 332, 333: Addition unit; 341, 342, 343: Addition unit; 351: Division unit; 410: Receiving antenna; 420: GPS receiving unit; 430: Position information acquisition unit; 500: Position synthesis unit; 610: Processing unit; 620: Communication unit; 630: Display unit; 1000: Mobile object positioning device; Ax: X-axis acceleration sensor element; Ay: Y-axis acceleration sensor element; Az: Z-axis acceleration sensor element; Gx: X-axis angular velocity sensor element; Gy: Y-axis angular velocity sensor element; Gz1, Gz2, Gz3, Gz4: Z-axis angular velocity sensor element; A1, A2, A3, A4: Weight coefficients. DETAILED DESCRIPTION

[0020] In order to make components easier to see, the components may be shown in different scales in the drawings.

[0021] 1. Implementation Method 1

[0022] 1.1. Inertial Measurement Unit

[0023] Figures 1 to 4 An inertial measurement unit 100 (IMU: Inertial Measurement Unit) is shown as a sensor module.

[0024] Figure 1 2 is a block diagram showing the configuration of inertial measurement device 100 . Figure 2 This is a diagram illustrating the sensor coordinate system. Figure 3 1 is a perspective view showing the appearance of inertial measurement device 100 . Figure 4 2 is a block diagram showing the configuration of correction circuit 40 of inertial measurement device 100 .

[0025] In the present embodiment, inertial measurement device 100 measures angular velocity and / or acceleration of inertial measurement device 100 in a sensor coordinate system.

[0026] The inertial measurement unit 100 is installed in electronic devices such as portable devices like smartphones and mobile objects like automobiles, as described later, to detect the posture and behavior of these electronic devices. Furthermore, the inertial measurement unit 100 is used in the mobile object positioning device described later. This mobile object positioning device is installed in mobile objects such as automobiles and is used to calculate the posture and position of the mobile object.

[0027] 1.2. Sensor Coordinate System

[0028] The sensor coordinate system of inertial measurement device 100 is a three-dimensional orthogonal coordinate system composed of three coordinate axes: the X-axis, the Y-axis, and the Z-axis.

[0029] Figure 2 1 is a diagram illustrating the relationship between the sensor coordinate system of inertial measurement device 100 and the moving direction of vehicle 130 equipped with inertial measurement device 100. Inertial measurement device 100 is mounted on vehicle 130 so that the sensor coordinate system satisfies the following predetermined relationship with respect to vehicle 130.

[0030] In this embodiment, the X-axis of the sensor coordinate system of inertial measurement device 100 is the front-rear direction of vehicle 130. The positive direction of the X-axis of the sensor coordinate system is the forward direction (moving direction) of vehicle 130.

[0031] The Y-axis of the sensor coordinate system of the inertial measurement device 100 is the left-right direction of the car 130 . The positive direction of the Y-axis of the sensor coordinate system is the right direction of the car 130 .

[0032] The Z-axis of the sensor coordinate system of inertial measurement unit 100 is perpendicular to the X-axis and Y-axis and represents the vertical direction of vehicle 130. The positive Z-axis direction of the sensor coordinate system represents the downward direction of vehicle 130. Because vehicle 130 moves in a substantially horizontal plane, the XY plane represents the plane of motion of the moving object, and the positive Z-axis direction is considered to coincide with the direction of gravity.

[0033] The posture of vehicle 130 is represented by the roll angle around the X-axis, the pitch angle around the Y-axis, and the yaw angle around the Z-axis. The roll angle corresponds to the left-right tilt of vehicle 130, the pitch angle corresponds to the front-back tilt of vehicle 130, and the yaw angle corresponds to the direction of movement or orientation of vehicle 130.

[0034] The inventors' experiments and discussions have led to the following conclusion: When the inertial measurement device 100 is used in a mobile body positioning device, in order to effectively improve the positioning accuracy, it is best to make the accuracy of the yaw angle measurement value of the inertial measurement device 100 higher than the accuracy of the roll and pitch angle measurement values.

[0035] In the inertial measurement unit 100 of this embodiment, the accuracy of the angular velocity around the Z axis, which represents the yaw angle, is higher than the accuracy of the angular velocity around the X axis and the angular velocity around the Y axis. Therefore, inertial measurement unit 100 is designed to include multiple different types of Z-axis angular velocity sensor elements, and these multiple types of Z-axis angular velocity sensor elements are used to obtain higher-accuracy angular velocity around the Z axis. Details will be described in Section 1.4 below.

[0036] 1.3. Appearance

[0037] Figure 3 1 is a perspective view showing the appearance of inertial measurement device 100 .

[0038] like Figure 3 As shown, inertial measurement device 100 includes housing 1. Housing 1 is in the shape of a cube, and has dimensions such that the length of one side of the square is, for example, approximately 24 mm and the thickness is approximately 10 mm.

[0039] The housing 1 is a housing that houses a plurality of inertial sensors described below and is composed of a case 2 and a cover 3 .

[0040] A plurality of inertial sensors and the like described later are housed in the case 2 .

[0041] Frame 1 has screw holes 4. Screws 7 are inserted through these two screw holes 4, whereby inertial measurement device 100 is fixed to a mounting surface 8 of a mounting device such as automobile 130 for use.

[0042] 1.4. Functional block composition

[0043] Figure 1 is a block diagram showing the functional block configuration of inertial measurement device 100 .

[0044] like Figure 1 As shown, inertial measurement unit 100 includes a first sensor 10 , a second sensor 20 , a data processing circuit 50 , and an I / F circuit 60 .

[0045] 1.4.1. Inertial Sensors

[0046] Inertial measurement device 100 includes first sensor 10 and second sensor 20 as inertial sensors that detect angular velocity and / or acceleration as physical quantities.

[0047] First sensor 10 and second sensor 20 are different types of inertial sensors. In other words, first sensor 10 and second sensor 20 are inertial sensors with different performance and / or characteristics. Furthermore, inertial measurement unit 100 is designed to perform high-precision detection using these different types of first and second sensors 10, 20.

[0048] In the present embodiment, the first sensor 10 is a Si-MEMS (Micro Electro Mechanical Systems) sensor using silicon (Si) as a material.

[0049] In this embodiment, the second sensor 20 is a crystal gyro sensor using crystal (SiO 2 ) as a material.

[0050] The first sensor 10 and the second sensor 20 are not limited to Si-MEMS sensors or crystal gyro sensors. For example, the first sensor 10 and the second sensor 20 may employ a MEMS sensor made of LiNbO3 (lithium niobate), a fiber-optic gyroscope (FOG), a ring laser gyroscope (RLG), an aerodynamic gyro sensor, or a rotary gyro sensor. In other words, in the inertial measurement unit 100 of this embodiment, the first sensor 10 and the second sensor 20 employ different types of inertial sensors from these.

[0051] The first sensor 10 and the second sensor 20 are inertial sensors that detect the same physical quantity. Inertial measurement device 100 has redundancy by including a plurality of inertial sensors that detect the same physical quantity.

[0052] In this embodiment, the first sensor 10 and the second sensor 20 detect the same physical quantity, the angular velocity about the Z axis. In this embodiment, the angular velocity about the Z axis is an example of the first physical quantity. The first physical quantity is not limited to the angular velocity about the Z axis. The first physical quantity may also be the angular velocity about the X axis, the angular velocity about the Y axis, the acceleration in the X-axis direction, the acceleration in the Y-axis direction, or the acceleration in the Z-axis direction, and the first physical quantity may be appropriately selected depending on the purpose and application.

[0053] 1.4.1.1. First sensor

[0054] The first sensor 10 is a multi-axis inertial sensor that detects three-dimensional inertial motion. Specifically, the first sensor 10 is a six-axis inertial sensor that detects translational and rotational motion in three orthogonal directions of the sensor coordinate system. In other words, the first sensor 10 is a 6Dof (Degrees of Freedom) sensor.

[0055] The first sensor 10 includes an X-axis acceleration sensor element Ax, a Y-axis acceleration sensor element Ay, a Z-axis acceleration sensor element Az, an X-axis angular velocity sensor element Gx, a Y-axis angular velocity sensor element Gy, and a Z-axis angular velocity sensor element Gz1.

[0056] The X-axis acceleration sensor element Ax detects the acceleration in the X-axis direction and outputs the acceleration α x As a detection signal.

[0057] The Y-axis acceleration sensor element Ay detects the acceleration in the Y-axis direction and outputs the acceleration α y As a detection signal.

[0058] The Z-axis acceleration sensor element Az detects the acceleration in the Z-axis direction and outputs the acceleration α z As a detection signal.

[0059] The X-axis angular velocity sensor element Gx detects the angular velocity around the X-axis and outputs the angular velocity ω x As a detection signal.

[0060] The Y-axis angular velocity sensor element Gy detects the angular velocity around the Y-axis and outputs the angular velocity ω y As a detection signal.

[0061] The Z-axis angular velocity sensor element Gz1 detects the angular velocity around the Z axis and outputs the angular velocity ω z1 As the detection signal In the present embodiment, the Z-axis angular velocity sensor element Gz1 is an example of a first inertial sensor element among a plurality of inertial sensor elements.

[0062] In this embodiment, the first sensor 10 is a capacitance-variable Si-MEMS sensor. The X-axis acceleration sensor element Ax, the Y-axis acceleration sensor element Ay, the Z-axis acceleration sensor element Az, the X-axis angular velocity sensor element Gx, the Y-axis angular velocity sensor element Gy, and the Z-axis angular velocity sensor element Gz1 are preferably formed on a single silicon chip. Alternatively, they may be formed on multiple separate silicon chips and packaged in a single packaging material.

[0063] 1.4.1.2. Second sensor

[0064] The second sensor 20 is a crystal gyro sensor.

[0065] The second sensor 20 includes a Z-axis angular velocity sensor element Gz2 that detects an angular velocity around the Z axis based on the Coriolis force applied to the crystal oscillator and outputs an angular velocity ω. z2As the detection signal In the present embodiment, the Z-axis angular velocity sensor element Gz2 is an example of a second inertial sensor element among the plurality of inertial sensor elements.

[0066] Angular velocity ω of the Z-axis angular velocity sensor element Gz2 z2 The error is less than the angular velocity ω of the first sensor 10 z1 In other words, the Z-axis angular velocity sensor element Gz2 is a high-precision sensor element compared to the Z-axis angular velocity sensor element Gz1.

[0067] 1.4.2. Data processing circuit

[0068] The data processing circuit 50 includes a calculation circuit 30 and a correction circuit 40 .

[0069] The data processing circuit 50 is comprised of a processor such as an MPU (Micro Processing Unit), a DSP (Digital Signal Processor), or an ASIC (Application Specific Integrated Circuit). The data processing circuit 50 executes various processes in the calculation circuit 30 and the correction circuit 40 based on programs stored in a memory unit (not shown). The calculation circuit 30 and the correction circuit 40 may also be programs that cause the processor to perform calculation and correction functions. The data processing circuit 50 is preferably a single-chip processor, but may also be comprised of multiple chips.

[0070] 1.4.2.1. Operational Circuit

[0071] The calculation circuit 30 calculates the angular velocity ω of the Z-axis angular velocity sensor element Gz1. z1 The angular velocity ω of the Z-axis angular velocity sensor element Gz2 z2 Perform weighted averaging and output the composite angular velocity ω as the weighted average detection signal z .

[0072] Resultant angular velocity ω z The accuracy is higher than the angular velocity ω of the Z-axis angular velocity sensor element Gz1 z1 and the angular velocity ω of the Z-axis angular velocity sensor element Gz2 z2 In other words, the calculation circuit 30 uses a plurality of Z-axis angular velocity sensor elements Gz1 and Gz2 of different types, and outputs an angular velocity ω of the Z-axis angular velocity sensor elements Gz1 and Gz2. z1 、ω z2 High-precision synthetic angular velocity ω z .

[0073] The arithmetic circuit 30 includes multiplication units 31 and 32 and an addition unit 33 .

[0074] The multiplication unit 31 calculates the angular velocity ω of the Z-axis angular velocity sensor element Gz1 of the first sensor 10. z1 Multiply by weight coefficient A1. In this embodiment, weight coefficient A1 is an example of a first weight coefficient.

[0075] The multiplication unit 32 calculates the angular velocity ω of the Z-axis angular velocity sensor element Gz2 of the second sensor 20. z2 Multiply by weight coefficient A2. In this embodiment, weight coefficient A2 is an example of a second weight coefficient.

[0076] The adding unit 33 adds the output of the multiplying unit 31 and the output of the multiplying unit 32, and outputs a resultant angular velocity ω z .

[0077] Resultant angular velocity ω z Calculate using the following mathematical formula 1.

[0078] [Mathematical formula 1]

[0079]

[0080] The weight coefficient A1 and the weight coefficient A2 are values based on the performance of the Z-axis angular velocity sensor element Gz1 of the first sensor 10 and the performance of the Z-axis angular velocity sensor element Gz2 of the second sensor 20 , respectively.

[0081] In this embodiment, the weight coefficient A1 and the weight coefficient A2 are calculated based on the error RMS (Root Mean Square) of the Z-axis angular velocity sensor element Gz1 of the first sensor 10 and the error RMS of the Z-axis angular velocity sensor element Gz2 of the second sensor 20 .

[0082] When the RMS error of the Z-axis angular velocity sensor element Gz1 of the first sensor 10 is σ1 and the RMS error of the Z-axis angular velocity sensor element Gz2 of the second sensor 20 is σ2, the weight coefficient A1 is calculated by the following equation 2, and the weight coefficient A2 is calculated by the following equation 3. The calculated weight coefficients A1 and A2 are stored in a storage unit (not shown) and used for calculations in the calculation circuit 30.

[0083] [Mathematical formula 2]

[0084]

[0085] [Mathematical formula 3]

[0086]

[0087] Resultant angular velocity ω z The RMS errorσ z Calculate using Formula 4.

[0088] [Formula 4]

[0089]

[0090] Resultant angular velocity ω z The RMS error σ z Less than the RMS error σ of the Z-axis angular velocity sensor element Gz1 z And the error RMSσ2 of the Z-axis angular velocity sensor element Gz2.

[0091] The angular velocity ω of the Z-axis angular velocity sensor element Gz1 z1 and the angular velocity ω of the Z-axis angular velocity sensor element Gz2 z2 The included error (error dispersion σ 2 ), the width of the bandwidth B is related to the angular velocity noise density N0 or the angular random walk R ω The relevant components are considered to be decisive. Therefore, the angular velocity ω of the Z-axis angular velocity sensor element Gz1 is z1 and the angular velocity ω of the Z-axis angular velocity sensor element Gz2 z2 The included error dispersion σ 2 It can be estimated approximately by using Mathematical Formula 5. In other words, the weight coefficient can be based on the angular velocity noise density N0 or the angle random walk R ω To calculate.

[0092] [Formula 5]

[0093]

[0094] For example, in the following case, if the angular velocity noise density N of the Z-axis angular velocity sensor element Gz1 is 0，z1 The angular velocity noise density N of the Z-axis angular velocity sensor element Gz2 0，z2 The bandwidth B is the same, then the weight coefficient A1, weight coefficient A2 and synthetic noise density N 0，z Calculate using the following equations 6, 7, and 8.

[0095] [Formula 6]

[0096]

[0097] [Formula 7]

[0098]

[0099] [Formula 8]

[0100]

[0101] Synthetic noise density N 0，z is the angular velocity noise density N of the Z-axis angular velocity sensor element Gz1 0，z1 and the angular velocity noise density N of the Z-axis angular velocity sensor element Gz2 0，z2 In this example, the accuracy can be improved by 7% compared to using the high-precision Z-axis angular velocity sensor element Gz2 alone.

[0102] In this embodiment, the calculation circuit 30 is an example of a calculation unit. The sensor module 100a shown by the dotted line includes a Z-axis angular velocity sensor element Gz1, a Z-axis angular velocity sensor element Gz2, and the calculation circuit 30, and shows a minimum configuration as an example of a sensor module.

[0103] 1.4.2.2. Correction Circuit

[0104] Figure 4 is a block diagram of the correction circuit 40 .

[0105] like Figure 4 As shown, the correction circuit 40 includes single-axis correction units 41 , 42 , 43 , 44 , 45 , and 46 and an inter-axis correction unit 47 .

[0106] The uniaxial correction unit 41 corrects the acceleration α of the X-axis acceleration sensor element Ax. x Perform the desired calibration process, which may include temperature calibration, zero point calibration, sensitivity adjustment, filtering, etc.

[0107] The uniaxial correction unit 42 corrects the acceleration α of the Y-axis acceleration sensor element Ay. y Perform the desired correction process.

[0108] The uniaxial correction unit 43 corrects the acceleration α of the Z-axis acceleration sensor element Az. z Perform the desired correction processing.

[0109] The uniaxial correction unit 44 calculates the angular velocity ω of the X-axis angular velocity sensor element Gx. x Perform the desired correction processing.

[0110] The uniaxial correction unit 45 calculates the angular velocity ω of the Y-axis angular velocity sensor element Gy. y Perform the desired correction processing.

[0111] The uniaxial correction unit 46 calculates the composite angular velocity ω of the Z-axis angular velocity sensor element Gz1 and the Z-axis angular velocity sensor element Gz2. zIn this embodiment, the uniaxial correction unit 46 is arranged at the rear stage of the calculation circuit 30. The uniaxial correction unit 46 can be arranged between the Z-axis angular velocity sensor element Gz1 and the calculation circuit 30 and between the Z-axis angular velocity sensor element Gz2 and the calculation circuit 30. In this case, the calculation circuit 30 calculates the angular velocity ω after the correction process. z1 、ω z2 The resultant angular velocity ω z Perform calculation processing.

[0112] The inter-axis correction unit 47 performs alignment correction. Alignment correction is also called installation error correction. It is used to correct the acceleration α according to the deviation of the X-axis, Y-axis, and Z-axis directions of the first sensor 10 and the second sensor 20 from the reference. x , α y , α z , angular velocity ω x 、ω y and the resultant angular velocity ω z Make corrections.

[0113] 1.4.3.I / F Circuit

[0114] The I / F circuit 60 communicates with the host 200 based on a communication standard such as SPI (Serial Peripheral Interface) or I2C (Inter Integrated Circuit), including the detected composite angular velocity ω. z Interface processing related to the transmission and reception of data including inertial data.

[0115] Host 200 is a device that is electrically connected to inertial measurement device 100 and acquires inertial data output from inertial measurement device 100 .

[0116] The host 200 includes a processing unit (not shown), which can be implemented by a processor or the like, similarly to the aforementioned data processing circuit 50 .

[0117] For example, host 200 may be an electronic device as described below. The electronic device may be a mobile object such as automobile 130, an airplane, or a ship, or a portable device such as a smartphone, a personal computer, a touchscreen terminal, or a clock. The electronic device, such as a smartphone, calculates the posture of the electronic device based on inertial data output from inertial measurement unit 100.

[0118] For example, host computer 200 may also be part of a mobile positioning device, described below. The mobile positioning device includes, for example, an inertial measurement unit 100, a GPS receiver, and a receiving antenna for GPS reception. The mobile positioning device is mounted on a mobile object, such as a car 130, and calculates the attitude and position of the mobile object based on data from the inertial measurement unit 100 and the GPS receiver.

[0119] As described above, inertial measurement device 100 as a sensor module according to this embodiment achieves the following effects.

[0120] Inertial measurement device 100 of this embodiment includes: a plurality of inertial sensor elements, including: a Z-axis angular velocity sensor element Gz1 as a first inertial sensor element, which detects an angular velocity about the Z axis as a first physical quantity; and a Z-axis angular velocity sensor element Gz2 as a second inertial sensor element, which detects an angular velocity about the Z axis, and the plurality of inertial sensor elements are of a different type from that of Z-axis angular velocity sensor element Gz1, and each of the plurality of inertial sensor elements detects an angular velocity about the Z axis; and an arithmetic circuit 30 as a computing unit, which uses weight coefficients A1 and A2 as a plurality of weight coefficients to calculate angular velocity ω as detection signals of the plurality of inertial sensor elements. z1 、ω z2 Perform weighted average.

[0121] As described above, inertial measurement device 100 according to the present embodiment includes a plurality of inertial sensor elements of different types, and performs weighted averaging of detection signals from the plurality of inertial sensor elements using weight coefficients.

[0122] Therefore, inertial measurement device 100 of this embodiment can suppress the influence of combining multiple different types of inertial sensor elements and improve the accuracy of inertial measurement device 100. Specifically, inertial measurement device 100 can obtain more accurate detection results than using multiple different types of inertial sensor elements individually.

[0123] In the inertial measurement device 100 of this embodiment, the plurality of weight coefficients include a first weight coefficient A1 used by the Z-axis angular velocity sensor element Gz1 and a second weight coefficient A2 used by the Z-axis angular velocity sensor element Gz2 , and the weight coefficient A1 is different from the weight coefficient A2 .

[0124] As described above, inertial measurement device 100 according to the present embodiment includes a plurality of different types of inertial sensor elements, and performs weighted averaging on detection signals from the plurality of inertial sensor elements using different weighting coefficients.

[0125] Therefore, inertial measurement device 100 according to this embodiment can enhance the effectiveness of improving accuracy in a configuration including different types of inertial sensor elements.

[0126] In inertial measurement device 100 of this embodiment, the plurality of weight coefficients include weight coefficient A1 as a first weight coefficient based on error information of Z-axis angular velocity sensor element Gz1 and weight coefficient A2 as a second weight coefficient based on error information of Z-axis angular velocity sensor element Gz2.

[0127] As described above, inertial measurement device 100 according to the present embodiment includes different types of inertial sensor elements, and performs weighted averaging on detection signals from the plurality of inertial sensor elements using weighting coefficients based on error information of the inertial sensor elements.

[0128] Therefore, in the inertial measurement device 100 of the present embodiment, in a configuration including different types of inertial sensor elements, the effectiveness of improving accuracy can be enhanced by using the inertial sensor elements according to their performance.

[0129] 2. Implementation Method 2

[0130] Figure 5 This is a block diagram showing a functional block configuration of an inertial measurement unit 100 as a sensor module according to the second embodiment.

[0131] Embodiment 2 differs from Embodiment 1 in that it includes a fault detection circuit 61 and eliminates the detection signal of a faulty inertial sensor. Components identical or similar to those in Embodiment 1 are denoted by the same reference numerals, and their description is omitted.

[0132] 2.1. Inertial Sensors

[0133] Inertial measurement device 100 according to the second embodiment includes third sensor 23 and fourth sensor 24 in addition to first sensor 10 and second sensor 20 according to the first embodiment.

[0134] First sensor 10, second sensor 20, third sensor 23, and fourth sensor 24 are each different types of inertial sensors. In other words, first sensor 10, second sensor 20, third sensor 23, and fourth sensor 24 are inertial sensors with different performance and / or characteristics. Furthermore, inertial measurement unit 100 of Embodiment 2 is designed to perform high-precision detection using these different types of first sensor 10, second sensor 20, third sensor 23, and fourth sensor 24.

[0135] In the second embodiment, the third sensor 23 is a MEMS sensor made of LiNbO3, for example. The third sensor 23 has an output angular velocity ω z3 The Z-axis angular velocity sensor element Gz3 detects the signal.

[0136] In the second embodiment, the fourth sensor 24 is, for example, a fiber optic gyroscope. The fourth sensor 24 has an output angular velocity ω. z4 The Z-axis angular velocity sensor element Gz4 detects the signal.

[0137] The first sensor 10, the second sensor 20, the third sensor 23, and the fourth sensor 24 are not limited to Si-MEMS sensors, crystal gyro sensors, MEMS sensors using LiNbO3, and fiber optic gyroscopes. Any two of the first sensor 10, the second sensor 20, the third sensor 23, and the fourth sensor 24 may be different types of inertial sensors from the aforementioned inertial sensors. Furthermore, the first sensor 10, the second sensor 20, the third sensor 23, and the fourth sensor 24 may each be a different type of inertial sensor from the aforementioned different types, or any two of the first sensor 10, the second sensor 20, the third sensor 23, and the fourth sensor 24 may be the same type of inertial sensor from the aforementioned inertial sensors.

[0138] First sensor 10 , second sensor 20 , third sensor 23 , and fourth sensor 24 are inertial sensors that detect the same physical quantity. Inertial measurement device 100 includes a plurality of inertial sensors that detect the same physical quantity, thereby providing redundancy.

[0139] 2.2. Data processing circuit

[0140] The data processing circuit 50 includes a calculation circuit 300 , a correction circuit 40 , a fault detection circuit 61 , and a weight coefficient storage circuit 62 .

[0141] The fault detection circuit 61 monitors the first sensor 10 , the second sensor 20 , the third sensor 23 , and the fourth sensor 24 , and when a fault is detected, outputs information about the faulty inertial sensor to the calculation circuit 300 .

[0142] The weight coefficient storage circuit 62 outputs the weight coefficients A1, A2, A3, and A4 corresponding to the first sensor 10, the second sensor 20, the third sensor 23, and the fourth sensor 24, respectively, and resets the weight coefficient corresponding to the malfunctioning inertial sensor to zero. The reset weight coefficients are used to reset the detection signal of the malfunctioning inertial sensor to zero. In other words, the reset weight coefficients are used to eliminate the detection signal of the malfunctioning inertial sensor.

[0143] The weight coefficients A1, A2, A3, and A4 are values based on the performance of the Z-axis angular velocity sensor element Gz1 of the first sensor 10, the performance of the Z-axis angular velocity sensor element Gz2 of the second sensor 20, the performance of the Z-axis angular velocity sensor element Gz3 of the third sensor 23, and the performance of the Z-axis angular velocity sensor element Gz4 of the fourth sensor 24, respectively.

[0144] The calculation circuit 300 calculates the angular velocity ω of the Z-axis angular velocity sensor element Gz1. z1 , angular velocity ω of the Z-axis angular velocity sensor element Gz2 z2 , angular velocity ω of the Z-axis angular velocity sensor element Gz3 z3 and the angular velocity ω of the Z-axis angular velocity sensor element Gz4 z4 Perform weighted averaging and output the composite angular velocity ω as the weighted average detection signal z .

[0145] The arithmetic circuit 300 includes switches 311 , 312 , 313 , and 314 , multiplication units 321 , 322 , 323 , and 324 , addition units 331 , 332 , and 333 , addition units 341 , 342 , and 343 , and a division unit 351 .

[0146] Switch 311 switches the weight coefficient path to either the weight coefficient A1 side or the weight coefficient zero side output from weight coefficient storage circuit 62 based on the output from fault detection circuit 61. When fault detection circuit 61 detects a fault in first sensor 10, switch 311 switches the weight coefficient path from the weight coefficient A1 side to the zero side.

[0147] The switch 312 switches the path of the weight coefficient to one of the weight coefficient A2 side output from the weight coefficient storage circuit 62 or the weight coefficient zero side based on the output from the fault detection circuit 61 .

[0148] The switch 313 switches the path of the weight coefficient to either the weight coefficient A3 side output from the weight coefficient storage circuit 62 or the weight coefficient zero side based on the output from the fault detection circuit 61 .

[0149] The switch 314 switches the path of the weight coefficient to one of the weight coefficient A4 side output from the weight coefficient storage circuit 62 or the weight coefficient zero side based on the output from the fault detection circuit 61 .

[0150] The multiplication unit 321 calculates the angular velocity ω of the Z-axis angular velocity sensor element Gz1 of the first sensor 10. z1 The weight coefficient A1 supplied via the switch 311 is multiplied or the weight coefficient is reset to zero.

[0151] The multiplication unit 322 calculates the angular velocity ω of the Z-axis angular velocity sensor element Gz2 of the second sensor 20. z2 The weight coefficient A2 supplied via the switch 312 is multiplied or the weight coefficient is reset to zero.

[0152] The multiplication unit 323 calculates the angular velocity ω of the Z-axis angular velocity sensor element Gz3 of the third sensor 23. z3 The weight coefficient A3 supplied via the switch 313 is multiplied or the weight coefficient is reset to zero.

[0153] The multiplication unit 324 calculates the angular velocity ω of the Z-axis angular velocity sensor element Gz4 of the fourth sensor 24. z4 The weight coefficient A4 supplied via the switch 314 is multiplied or the weight coefficient is reset to zero.

[0154] The outputs of the multiplication units 321 , 322 , 323 , and 324 are summed by the addition units 331 , 332 , and 333 , and are supplied to the division unit 351 .

[0155] The outputs of the switches 311 , 312 , 313 , and 314 are summed by the adders 341 , 342 , and 343 and supplied to the divider 351 .

[0156] The division unit 351 divides the total value of the values obtained by multiplying the detection signals of the Z-axis angular velocity sensor elements Gz1, Gz2, Gz3, and Gz4 by their respective weight coefficients by the sum of the weight coefficients used for the multiplication, and uses the obtained value as the composite angular velocity ω z Output to the correction circuit 40.

[0157] As described above, according to inertial measurement unit 100 as a sensor module according to the second embodiment, in addition to the effects of the first embodiment, the following effects can be obtained.

[0158] The inertial measurement device 100 of the second embodiment further includes a fault detection circuit 61 as a detection unit for detecting a faulty inertial sensor element among the plurality of inertial sensor elements. The calculation circuit 300 as a calculation unit resets the weight coefficient used for the inertial sensor element detected to be faulty to zero through the fault detection circuit 61.

[0159] In this manner, inertial measurement device 100 according to the second embodiment resets the weighting coefficient used for the inertial sensor element in which a failure is detected to zero.

[0160] Therefore, inertial measurement device 100 according to the second embodiment can eliminate the influence of a failed inertial sensor in a configuration including different types of inertial sensor elements, thereby enhancing the effectiveness of improving accuracy.

[0161] 3. Implementation Method 3

[0162] In the third embodiment, an electronic device including inertial measurement device 100 will be described.

[0163] Hereinafter, as examples of electronic devices, portable devices such as smartphones and mobile objects such as automobiles 130 will be described.

[0164] 3.1. Overview of portable devices

[0165] Figure 6 1 is a perspective view of a portable device as an electronic device according to Embodiment 3, and is a diagram showing the configuration of a smartphone 110 as an example of the portable device.

[0166] Smartphone 110 is equipped with inertial measurement unit 100 .

[0167] The inertial data of the inertial measurement device 100 is received by the control unit 111. The control unit 111 recognizes the posture and behavior of the smartphone 110 based on the received inertial data and can change the displayed image, sound an alarm or sound effects, or drive a vibration motor to vibrate the main body.

[0168] The inertial measurement device 100 can also be installed in portable devices other than the smartphone 110. For example, it can be installed in portable devices such as smart watches, portable activity meters, HMDs (head-mounted displays), mobile PCs (personal computers), touch PCs, cameras, and PDAs (personal digital assistants). In this way, the portable device can recognize the device's posture and behavior based on inertial data from the inertial measurement device 100, and can change the displayed image, generate alarms or sound effects, or drive a vibration motor to vibrate the device.

[0169] As described above, in the third embodiment, a portable device such as a smartphone 110 as an electronic device is equipped with an inertial measurement unit 100 .

[0170] Therefore, according to the third embodiment, the performance of a portable device including inertial measurement device 100 can be improved.

[0171] 3.2. Overview of Mobile Objects

[0172] Figure 7 1 is a perspective view of a moving object as an electronic device according to Embodiment 3, and is a diagram showing the configuration of a car 130 as an example of the moving object.

[0173] Automobile 130 is equipped with inertial measurement device 100 .

[0174] The inertial measurement device 100 detects the posture of the vehicle body 131 and transmits inertial data to the vehicle body posture control device 132. The inertial data includes angular velocity and acceleration.

[0175] Upon receiving inertial data from the inertial measurement device 100 , the vehicle posture control device 132 that controls the posture of the vehicle body 131 detects the posture of the vehicle body 131 based on the signal, and controls the stiffness of the suspension or the braking of each wheel 133 according to the detection result.

[0176] In addition, the inertial measurement device 100's inertial data can be used in ECUs (electronic control units) for keyless entry, engine immobilizer, car navigation systems, car air conditioning, anti-lock braking systems (ABS), airbags, tire pressure monitoring systems (TPMS), engine controllers, control devices for inertial navigation used in autonomous driving, and battery monitors for hybrid and electric vehicles.

[0177] Inertial measurement unit 100 can be mounted on other mobile objects besides automobile 130. Examples of other mobile objects include bipedal robots, trains, airplanes, ships, radio-controlled airplanes, radio-controlled helicopters, drones, agricultural machinery such as tractors, and construction equipment. A mobile object equipped with inertial measurement unit 100 can utilize inertial data from the inertial measurement unit for posture control, position measurement, and other purposes.

[0178] As described above, in this embodiment, inertial measurement device 100 is mounted on a mobile object such as automobile 130 as an electronic device.

[0179] Therefore, according to the third embodiment, the performance of a mobile object including inertial measurement device 100 can be improved.

[0180] 4. Implementation Method 4

[0181] 4.1. Mobile Positioning Device

[0182] Figure 8 1 is a block diagram showing the entire system of the mobile object positioning device 1000 according to the fourth embodiment. Figure 9 1000 is a diagram showing the operation of the mobile object positioning device 1000 .

[0183] like Figure 9 As shown, the mobile object positioning device 1000 is, for example, a device that is mounted on a tractor 140 as a mobile object and measures the position of the tractor 140 .

[0184] The mobile object positioning device 1000 includes an inertial measurement device 100 , a processing unit 150 , a receiving antenna 410 , a GPS receiving unit 420 , a position information acquiring unit 430 , a position synthesis unit 500 , a processing unit 610 , a communication unit 620 , and a display unit 630 .

[0185] The processing unit 150 receives inertial data including three-axis acceleration and three-axis angular velocity from the inertial measurement device 100 , performs inertial navigation processing based on this inertial data, and outputs inertial navigation positioning data. The inertial navigation positioning data indicates the acceleration and posture of the tractor 140 .

[0186] The GPS receiving unit 420 receives satellite signals from GPS satellites via the receiving antenna 410. The GPS satellites transmit GPS carrier waves on which position information is superimposed as satellite signals.

[0187] Based on the satellite signals received by the GPS receiving unit 420, the position information acquisition unit 430 outputs GPS positioning data indicating the position, speed, and orientation of the mobile positioning device 1000. The GPS positioning data includes latitude, longitude, and altitude. Furthermore, the GPS positioning data also includes status data indicating the reception status and reception time.

[0188] The position synthesis unit 500 calculates the position of the mobile positioning device 1000 , specifically, the position on the ground where the tractor 140 is traveling, based on the inertial navigation positioning data output from the processing unit 150 and the GPS positioning data output from the position information acquisition unit 430 .

[0189] For example, even if the position of the tractor 140 included in the GPS positioning data is the same, as in Figure 9 As shown by the solid and dotted lines, the tractor 140's posture varies due to the influence of the ground tilt, causing the tractor 140 to travel at different locations on the ground. Therefore, the mobile positioning device 1000 cannot calculate the tractor 140's correct position based solely on GPS positioning data.

[0190] Therefore, the position synthesis unit 500 uses the inertial navigation positioning data from the processing unit 150, particularly data regarding the posture of the tractor 140, to calculate the position on the ground where the tractor 140 is traveling. This calculation can be performed relatively simply by using trigonometric functions, namely, calculating the tilt θ relative to the vertical direction.

[0191] The position data output from the position synthesis unit 500 is subjected to predetermined processing by the processing unit 610 and displayed as visual information on the display unit 630. Alternatively, the position data may be transmitted to an external device by the communication unit 620.

[0192] While the mobile positioning device 1000 of Embodiment 4 uses GPS as the satellite positioning system, other global navigation satellite systems (GNSS) may also be used. For example, one or more of the following satellite positioning systems may be used: EGNOS (European Geostationary-Satellite Navigation Overlay Service), QZSS (Quasi Zenith Satellite System), GLONASS (Global Navigation Satellite System), GALILEO, BeiDou (BeiDou Navigation Satellite System). Furthermore, a geostationary satellite-based navigation assistance system (SBAS), such as WAAS (Wide Area Augmentation System), may be used in at least one of the satellite positioning systems.

[0193] As described above, according to the mobile object positioning device 1000 of the fourth embodiment, in addition to the effects of the first, second, and third embodiments, the following effects can be obtained.

[0194] The mobile object positioning device 1000 according to the fourth embodiment includes: a plurality of inertial sensor elements, including: a Z-axis angular velocity sensor element Gz1 as a first inertial sensor element, which detects an angular velocity about the Z axis; a Z-axis angular velocity sensor element Gz2 as a second inertial sensor element, which detects an angular velocity about the Z axis and is of a different type from the Z-axis angular velocity sensor element Gz1, wherein the plurality of inertial sensor elements respectively detect an angular velocity about the Z axis; and an arithmetic circuit 30 as a calculation unit, which uses a plurality of weight coefficients A1 and A2 as a calculation unit to calculate the angular velocity ω of the detection signals of the plurality of inertial sensor elements. z1 、ω z2 The GPS receiving unit 420 as a receiving unit receives a satellite signal superimposed with position information from a positioning satellite; the position information acquiring unit 430 as an acquiring unit acquires the position information of the GPS receiving unit 420 based on the satellite signal; and the position synthesis unit 500 as a calculating unit calculates the position of the automobile 130 or the tractor 140 as a moving body based on the position information and the weighted averaged detection signal from the operation circuit 30.

[0195] As described above, the mobile object positioning device 1000 of the fourth embodiment performs weighted averaging of detection signals from a plurality of inertial sensor elements using weight coefficients, acquires position information based on satellite signals on which position information is superimposed, and calculates the position of the mobile object based on the position information and the weighted average detection signal.

[0196] Therefore, the mobile object positioning device 1000 of the fourth embodiment can suppress the influence of combining different types of inertial sensor elements, thereby improving the accuracy of the mobile object positioning device 1000. Specifically, compared to using multiple different types of inertial sensor elements individually, the inertial measurement device 100 can obtain higher-precision detection results, thereby improving the accuracy of the mobile object positioning device 1000 including the inertial measurement device 100.

[0197] Furthermore, as described above, in the inertial measurement device 100 of embodiments 1 and 2, the accuracy of the angular velocity around the Z axis, which is the yaw angle, is higher than the accuracy of the angular velocity around the X axis and the accuracy of the angular velocity around the Y axis. Therefore, the mobile object positioning device 1000 including the inertial measurement device 100 can provide a mobile object positioning device with high industrial application value.

[0198] In the fourth embodiment, a mobile object such as a car 130 or a tractor 140 is equipped with a mobile object positioning device 1000 .

[0199] Therefore, according to this embodiment, the performance of a mobile object including the mobile object positioning apparatus 1000 can be improved.

[0200] While preferred embodiments have been described above, the present invention is not limited to the above embodiments. The configuration of each part of the present invention can be replaced with any configuration that exhibits the same functions as the above embodiments, and any configuration can be added.

Claims

1. A sensor module, characterized in that: have: a plurality of inertial sensor elements, including: a first inertial sensor element that detects a first physical quantity; and a second inertial sensor element that detects the first physical quantity and is of a different type from the first inertial sensor element, wherein the plurality of inertial sensor elements respectively detect the first physical quantity; and The calculation unit performs weighted averaging on the detection signals of the plurality of inertial sensor elements using a plurality of weight coefficients.

2. The sensor module according to claim 1, wherein: The plurality of weight coefficients include a first weight coefficient used by the first inertial sensor element and a second weight coefficient used by the second inertial sensor element. The first weight coefficient is different from the second weight coefficient.

3. The sensor module according to claim 1, wherein: The plurality of weight coefficients include a first weight coefficient based on error information of the first inertial sensor element and a second weight coefficient based on error information of the second inertial sensor element.

4. The sensor module according to claim 1, wherein: The sensor module includes an inspection unit that inspects a malfunctioning inertial sensor element among the plurality of inertial sensor elements. The calculation unit resets the weighting coefficient used for the inertial sensor element detected as having a fault to zero according to the inspection unit.

5. An electronic device, characterized in that: A sensor module according to any one of claims 1 to 4 is provided.

6. A mobile body positioning device, characterized in that: have A plurality of inertial sensor elements, including: a first inertial sensor element that detects a first physical quantity; and a second inertial sensor element that detects the first physical quantity and is of a different type from the first inertial sensor element, wherein the plurality of inertial sensor elements respectively detect the first physical quantity; a calculation unit configured to perform a weighted average on the detection signals of the plurality of inertial sensor elements using a plurality of weight coefficients; a receiving unit that receives a satellite signal on which position information is superimposed from a positioning satellite; an acquiring unit that acquires the position information based on the satellite signal; and The calculation unit calculates the position of the moving object based on the position information and the weighted average detection signal from the calculation unit.

7. A mobile object, characterized in that: A mobile object positioning device according to claim 6 is provided.

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