This application is based upon and claims the benefit of priority from Japanese Patent Application No.2021-187034, filed on Nov. 17, 2021; the entire contents of which are incorporated herein by reference.
Embodiments described herein relate generally to a sensor and an electronic device.
There is a sensor such as a gyro sensor or the like. It is desirable to improve the detection accuracy of a sensor and an electronic device.
According to one embodiment, a sensor includes a sensor element, and a controller. The sensor element includes a first sensor part. The first sensor part includes a first movable part which can vibrate. Vibration of the first movable part includes a first component in a first direction and a second component in a second direction. The second direction crosses the first direction. The controller is configured to perform a first mode operation, a second mode operation, and a third mode operation. In the first mode operation, the controller is configured to derive a first rotation angle of the first movable part based on a first amplitude of the first component and a second amplitude of the second component. In the second mode operation, the controller is configured to derive a first angular velocity of the first movable part based on a change of a control signal. The control signal causes a rotation angle of the first movable part to be constant. In the third mode operation, the controller is configured to supply a third mode signal to the first sensor part. The third mode signal causes the rotation angle of the first movable part to change.
According to one embodiment, a sensor includes a sensor element, and a controller. The sensor element includes a first sensor part and a second sensor part. The first sensor part includes a first movable part which can vibrate. Vibration of the first movable part includes a first component in a first direction and a second component in a second direction. The second direction crosses the first direction. The second sensor part includes a second movable part which can vibrate. Vibration of the second movable part includes a third component in a third direction and a fourth component in a fourth direction. The fourth direction crosses the third direction. The controller is configured to perform a first mode operation, a second mode operation, a third mode operation, and a fourth mode operation. In the first mode operation, the controller is configured to derive a first rotation angle of the first movable part based on a first amplitude of the first component and a second amplitude of the second component. In the second mode operation, the controller is configured to derive a second angular velocity of the second movable part based on a change of a control signal. The control signal causes a rotation angle of the second movable part to be constant. In the third mode operation, the controller is configured to supply a third mode signal to the first sensor part. The third mode signal causes a rotation angle of the first movable part to change. In the fourth mode operation, the controller is configured to supply a fourth mode signal to the second sensor part. The fourth mode signal causes the rotation angle of the second movable part to change.
According to one embodiment, an electronic device includes the sensor described above, and a circuit controller. The circuit controller is configured to control a circuit based on a signal obtained from the sensor.
Various embodiments are described below with reference to the accompanying drawings.
The drawings are schematic and conceptual; and the relationships between the thickness and width of portions, the proportions of sizes among portions, etc., are not necessarily the same as the actual values. The dimensions and proportions may be illustrated differently among drawings, even for identical portions.
In the specification and drawings, components similar to those described previously or illustrated in an antecedent drawing are marked with like reference numerals, and a detailed description is omitted as appropriate.
As shown in
For example, the controller 70 includes a first detector 71a, a second detector 71b, and a third detector 71c. The first detector 71a is configured to detect the amplitude (first amplitude Ax) of the first component in the first direction D1 based on the signal obtained from the first sensor part 10U. The second detector 71b is configured to detect the amplitude (second amplitude Ay) of the second component in the second direction D2 based on the signal obtained from the first sensor part 10U.
The third detector 71c is configured to derive a rotation angle θ based on a ratio of the first amplitude Ax and the second amplitude Ay, for example. For example, the rotation angle θ corresponds to, for example, tan-1 (-Ay / Ax).
The controller 70 is configured to perform a first mode operation OP1, a second mode operation OP2, and a third mode operation OP3. These operations are switched and performed.
For example, the controller 70 includes, for example, a mode controller 75. The first to third mode operations OP1 to OP3 are switched by the operation of the mode controller 75.
In the first mode operation OP1, the controller 70 is configured to derive the first rotation angle θ1 of the first movable part 10M based on the first amplitude Ax of the first component and the second amplitude Ay of the second component. In the first mode operation OP1, the rotation angle θ based on the above ratio is output as the first rotation angle θ1. The first mode operation OP1 corresponds to, for example, a WA (Whole Angle) mode.
For example, the controller 70 includes a first drive circuit 72a and a second drive circuit 72b. A first drive signal Vd1 is supplied from the first drive circuit 72a to the first sensor part 10U. A second drive signal Vd2 is supplied from the second drive circuit 72b to the first sensor part 10U. These drive signals cause the first movable part 10M to vibrate.
For example, an external force (acceleration) accompanied by rotation is applied to the first sensor part 10U. The vibration state (rotation angle) of the first movable part 10M changes according to the external force. For example, the vibration state changes due to the action of Coriolis force. Due to the change in the vibration state, the first amplitude Ax of the first component and the second amplitude Ay of the second component change. By detecting the ratio of these amplitudes, the rotation angle generated by the external force can be detected.
In the second mode operation OP2, the controller 70 is configured to derive a first angular velocity Ω1 of the first movable part based on a change of a control signal Sc0 so that the rotation angle of the first movable part 10M becomes constant. As described above, for example, the rotation angle of the first movable part 10M changes according to the external force. In the second mode operation OP2, when the external force is applied, the control signal Sc0 in which the rotation angle does not change and becomes constant is detected. For example, in the second mode operation OP2, the first drive signal Vd1 and the second drive signal Vd2 change based on the control signal Sc0. By controlling the control signal Sc0, the rotation angle of the first movable part 10M can be made constant regardless of the rotation due to the external force. By detecting such a control signal Sc0 (or the first drive signal Vd1 and the second drive signal Vd2), the angular velocity due to the external force (first angular velocity Ω1) can be known. The second mode operation OP2 corresponds to, for example, the FR (Force Rebalance) mode.
In the third mode operation OP3, the controller 70 is configured to supply a third mode signal Sm3 (for example, a voltage signal) to the first sensor part 10U. The third mode signal Sm3 arbitrarily changes the rotation angle of the first movable part 10M. For example, the controller 70 supplies a third mode control signal Sc3, which is the basis of the third mode signal Sm3, to the first drive circuit 72a and the second drive circuit 72b. The third mode signal Sm3 based on the third mode control signal Sc3 is supplied to the first sensor part 10U from the first drive circuit 72a and the second drive circuit 72b. The third mode signal Sm3 can vibrate the first movable part 10M at an arbitrary (desired) angle of rotation. The third mode operation OP3 is, for example, a VR (Virtual Rotation) mode. The third mode operation OP3 is performed, for example, at the time of calibrating the sensor.
As will be described later, in the first mode operation OP1, when the angular velocity of the vibration of the first movable part 10M is high, the first rotation angle θ1 can be detected with high accuracy. In the second mode operation OP2, when the angular velocity of the vibration of the first movable part 10M is low, the first angular velocity Ω1 can be detected with high accuracy. By switching and performing these operation modes, it is possible to detect with high accuracy over a wide dynamic range. On the other hand, the third mode operation OP3 is configured to be performed in which the first movable part 10M is vibrated at an arbitrary rotation angle. This facilitates calibration. According to the embodiment, it is possible to provide a sensor capable of improving accuracy.
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Hereinafter, an example of the operation of the controller 70 will be described.
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The first state ST1 and the second state ST2 may be switched, for example, by setting of the user. Alternatively, the mode controller 75 may detect a vibration state (for example, angular velocity) of the first movable part 10M, and distinguish the detection state or the calibration state based on the detection result.
In the second state ST2, the third mode operation OP3 is performed (step S13).
For example, in the first state ST1, the angular velocity Q is detected (estimated) (step S14). The detection of the angular velocity Q is performed by, for example, the angular velocity detector 76. The angular velocity detector 76 is included in the controller 70. The detection of the angular velocity Q may be performed by, for example, the first detector 71a and the second detector 71b.
The mode controller 75 selects the first mode operation OP1 and the second mode operation OP2 based on the detected angular velocity Q (mode control process: step S10). For example, the controller 70 performs the second mode operation OP2 when the detected angular velocity Q of the first movable part 10M is not more than a first threshold value Qth (step S12). The controller 70 performs the first mode operation OP1 when the detected angular velocity Q exceeds the first threshold value Qth (step S11).
In the first state ST1, the selection of the first mode operation OP1 and the second mode operation OP2 may be repeatedly performed according to the detected angular velocity Q.
As described above, in the first mode operation OP1, the controller 70 derives the first rotation angle θ1 based on a ratio of the first amplitude Ax of the first component and the second amplitude Ay of the second component. In the second mode operation OP2, the controller 70 derives the first angular velocity Ω1 based on a change of the control signal Sc0 so that the vibration state of the first movable part 10M becomes constant.
Hereinafter, an example of the characteristics of the sensor in the first to third mode operations OP1 to OP3 will be described.
In the first mode operation OP1 of
In the second mode operation OP2 of
The characteristics in the first mode operation OP1 and the characteristics in the second mode operation OP2 are complementary. By switching and performing these operations, highly accurate detection becomes possible over a wide range of angular velocities.
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Hereinafter, an example of the structure of the sensor 110 will be described.
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The sensor element 10D is between the first member 81a and the second member 81b. A direction from the first member 81a to the second member 81b corresponds to the Z-axis direction.
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The first sensor part 10U is, for example, an angle gyro sensor. The first sensor part 10U is, for example, a RIG (Rate Integrating Gyroscope). The first sensor part 10U can directly measure the rotation angle of the detection target.
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A direction from the first fixed part 10F to the first counter vibration electrode 11CE and a direction from the first fixed part 10F to the second counter vibration electrode 12CE cross the Z-axis direction (the direction from the first base body region 50Sa to the first fixed part 10F). In this example, a direction from the first fixed part 10F to the first counter vibration electrode 11CE is along the Z-axis direction. A direction from the first fixed part 10F to the second counter vibration electrode 12CE is along the Y-axis direction.
The direction from the first fixed part 10F to the first counter vibration electrode 11CE (for example, the X-axis direction) crosses the direction from the first fixed part 10F to the second counter vibration electrode 12CE (for example, the Y-axis direction).
For example, the controller 70 is configured to supply the first drive signal Vd1 (for example, the first drive voltage) between the first vibration electrode 11E and the first counter vibration electrode 11CE. The controller 70 supplies the second drive signal Vd2 (for example, the second drive voltage) between the second vibration electrode 12E and the second counter vibration electrode 12CE. The first movable part 10M vibrates due to these drive signals. Vibration has components in two directions.
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The first fixed part 10F is between the first vibration electrode 11E and the first sensing electrode 11sE. The first fixed part 10F is between the second vibration electrode 12E and the second sensing electrode 12sE. For example, with the vibration of the first movable part 10M, the first sense signal Vs1 is generated between the first sensing electrode 11sE and the first counter sensing electrode 11CsE. For example, with the vibration of the first movable part 10M, the second sense signal Vs2 is generated between the second sensing electrode 12sE and the second counter sensing electrode 12CsE. The controller 70 acquires these signals.
The controller 70 includes, for example, a first amplifier 17a and a second amplifier 17b. The first sense signal Vs1 is input to the first amplifier 17a. The second sense signal Vs2 is input to the second amplifier 17b. The sense signal is amplified by these amplifiers.
In the first mode operation OP1, the controller 70 detects a first rotation angle θ1 (see
In the second mode operation OP2, the controller 70 supplies, for example, a signal (a first drive signal Vd1 and a second drive signal Vd2) based on a control signal Sc0 (see
In the third mode operation OP3, the controller 70 supplies a signal corresponding to the third mode signal Sm3 (for example, voltage) to at least one of the first counter vibration electrode 11CE or the second counter vibration electrode 12CE.
The first gap g1 (see
The first counter vibration electrode 11CE, the second counter vibration electrode 12CE, the first counter sensing electrode 11CsE, and the second counter sensing electrode 12CsE are fixed to the base body 50S.
As shown in
For example, the first sensor part 10U includes the first movable part 10M that can vibrate. The vibration of the first movable part 10M includes a first component of the first direction D1 and a second component of the second direction D2 crossing the first direction D1 (see
For example, the second sensor part 20U includes a second movable part 20M that can vibrate. The vibration of the second movable part 20M includes a third component in a third direction and a fourth component in a fourth direction crossing the third direction. The third direction may be along one of the first direction D1 and the second direction D2 (for example, the first direction D1). The fourth direction may be along the other one of the first direction D1 and the second direction D2 (for example, the second direction D2).
In this example, the sensor element 10D includes the base body 50S. As shown in
The first sensor part 10U includes the first fixed part 10F and the first supporter 10S. The first fixed part 10F is fixed to the first base body region 50Sa. The first supporter 10S is supported by the first fixed part 10F. The first supporter 10S supports the first movable part 10M. The first gap g1 is provided between the base body 50S and the first supporter 10S, and between the base body 50S and the first movable part 10M.
The second sensor part 20U includes a second fixed part 20F and a second supporter 20S. The second fixed part 20F is fixed to the second base body region 50Sb. The second supporter 20S is supported by the second fixed part 20F. The second supporter 20S supports the second movable part 20M. A fourth gap g4 is provided between the base body 50S and the second supporter 20S, and between the base body 50S and the second movable part 20M.
In this example as well, the housing 80 is provided. As shown in
Hereinafter, an example of the operation in the sensor 120 will be described.
As shown in
In the first state ST1, a first mode operation OP1 is applied to the first sensor part 10U. In the first state ST1, a second mode operation OP2 is applied to the second sensor part 20U. In the second state ST2, a third mode operation OP3 is applied to the first sensor part 10U. In the second state ST2, a fourth mode operation OP4 is applied to the second sensor part 20U. Such operations are controlled by the controller 70.
The controller 70 is configured to perform the first mode operation OP1, the second mode operation OP2, the third mode operation OP3, and the fourth mode operation OP4. The first mode operation OP1 and the third mode operation OP3 are switched and performed. The second mode operation OP2 and the fourth mode operation OP4 are switched and performed.
In the first mode operation OP1, the controller 70 is configured to derive the first rotation angle θ1 of the first sensor part 10U based on the first amplitude Ax of the first component and the second amplitude Ay of the second component.
In the second mode operation OP2, the controller70 is configured to derive a second angular velocity Ω2 of the second sensor part 20U based on a change in the control signal Sc0 (see
In the third mode operation OP3, the controller 70 is configured to supply the third mode signal Sm3 for changing the rotation angle of the first movable part 10M to the first sensor part 10U. In the third mode operation OP3, the first movable part 10M can be vibrated at an arbitrary rotation angle (third mode angle).
In the fourth mode operation OP4, the controller 70 is configured to supply a fourth mode signal Sm4 for changing the rotation angle of the second movable part 20M to the second sensor part 20U. In the fourth mode operation OP4, the second movable part 20M can be vibrated at an arbitrary rotation angle (fourth mode angle). For example, at the time of calibration, the third mode operation OP3 and the fourth mode operation OP4 are performed.
As described above with respect to the first embodiment, for example, the first angular velocity Ω1 may be derived from the first rotation angle θ1 obtained in the first mode operation OP1. The second angle of rotation θ2 may be derived from the second angular velocity Ω2 obtained in the second mode operation OP2,
In the first state ST1, a calculation result VA1 based on the first rotation angle θ1 derived in the first mode operation OP1 and the second angular velocity Ω2 derived in the second mode operation OP2 may be output from the controller 70.
For example, the controller 70 may include an angle calculator 77. The angle calculator 77 is configured to output tile calculation result VA1 derived by the calculation based on the first rotation angle θ1 and the second angular velocity Ω2. The calculation result VA1 is a rotation angle. In another example, the calculation result VA1 is an angular velocity. For example, the calculation result VA1 includes one of the first rotation angle θ1 and the second rotation angle θ2 derived from the second angular velocity Q2. For example, when the angular velocity Q exceeds the threshold value Qth, the first rotation angle θ1 is output as the calculation result VA1. For example, when the angular velocity Q is not more than the threshold value Qth, the second rotation angle θ2 derived from the second angular velocity Ω2 may be output as the calculation result VA1.
In another example, multiple regions are defined with respect to the angular velocity Q, and in the multiple regions, the calculation result of the detection result by the first mode operation OP1 and the calculation result of the detection result by the second mode operation OP2 are output as the calculation result VA1. The content of the calculation may be changed according to the multiple regions relating to the angular velocity Q. In the calculation, for example, a weight related to the detection result by the first mode operation OP1 and the detection result by the second mode operation OP2 may be set. The weight may be changed depending on the multiple regions with respect to the angular velocity Q.
The sensor 120 can detect with high accuracy in a wide dynamic range.
In the sensor 120, the configuration of the first sensor part 10U may be the same as the configuration of the first sensor part 10U in the sensor 110 (see
As described with respect to
Hereinafter, an example of the second sensor part 20U will be described.
The second movable part 20M includes a third vibration electrode 23E and a fourth vibration electrode 24E. The second sensor counter electrode 20CE includes a third counter vibration electrode 23CE facing the third vibration electrode 23E and a fourth counter vibration electrode 24CE facing the fourth vibration electrode 24E. A direction from the second fixed part 20F to the third counter vibration electrode 23CE and a direction from the second fixed part 20F to the fourth counter vibration electrode 24CE cross the above-mentioned stacking direction (for example, the Z-axis direction). The direction from the second fixed part 20F to the third counter vibration electrode 23CE (for example, the X-axis direction) crosses the direction from the second fixed part 20F to the fourth counter vibration electrode 24CE (for example, the Y-axis direction).
The second movable part 20M includes a third sensing electrode 23sE and a fourth sensing electrode 24sE. The second sensor counter electrode 20CE includes a third counter sensing electrode 23CsE facing the third sensing electrode 23sE and a fourth counter sensing electrode 24CsE facing the fourth sensing electrode 24sE. The second fixed part 20F is between the third vibration electrode 23E and the third sensing electrode 23sE. The second fixed part 20F is between the fourth vibration electrode 24E and the fourth sensing electrode 24sE.
For example, with the vibration of the second movable part 20M, a third sense signal Vs3 is generated between the third sensing electrode 23sE and the third counter sensing electrode 23CsE. For example, with the vibration of the second movable part 20M, a fourth sense signal Vs4 is generated between the fourth sensing electrode 24sE and the fourth counter sensing electrode 24CsE. The controller 70 acquires these signals.
The controller 70 includes, for example, a third amplifier 17c and a fourth amplifier 17d. The third sense signal Vs3 is input to the third amplifier 17c. The fourth sense signal Vs4 is input to the fourth amplifier 17d. The sense signals are amplified by these amplifiers.
The controller 70 supplies a third drive signal Vd3 to the third counter vibration electrode 23CE. The third drive signal Vd3 is applied between the third vibration electrode 23E and the third counter vibration electrode 23CE. The controller 70 supplies a fourth drive signal Vd4 to the fourth counter vibration electrode 24CE, The fourth drive signal Vd4 is applied between the fourth vibration electrode 24E and the fourth counter vibration electrode 24CE. These drive signals cause the second movable part 20M to vibrate.
For example, in the second mode operation OP2, the third drive signal Vd3 and the fourth drive signal Vd4 change based on the control signal Sc0 (see
For example, in the fourth mode operation OP4, the controller 70 supplies a signal corresponding to the fourth mode signal Sm4 (for example, voltage) to at least one of the third counter vibration electrode 23CE and the fourth counter vibration electrode 24CE,
The third embodiment relates to an electronic device.
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The embodiment may include the following configurations (e.g., technical proposals).
A sensor, comprising:
The sensor according to Configuration 1, wherein
in the first mode operation, the controller is configured to derive the first rotation angle based on a ratio of the first amplitude of the first component and the second amplitude of the second component.
The sensor according to Configuration 1 or 2, wherein
the controller performs the third mode operation at a time of calibrating the first sensor part.
The sensor according to any one of Configurations 1 to 3, wherein
The sensor according to any one of Configurations 1 to 4, wherein
The sensor according to Configuration 5, wherein
in a plane crossing a direction from the first base body region to the first fixed part, the first movable part is provided around at least a part of the first fixed part.
The sensor according to Configuration 5, wherein
The sensor according to Configuration 7, wherein
The sensor according to Configuration 8, wherein
the controller derives the first rotation angle based on a first sense signal between the first sensing electrode and the first counter sensing electrode, and a second sense signal between the second sensing electrode and the second counter sensing electrode in the first mode operation.
The sensor according to any one of Configurations 7 to 9, wherein
the controller supplies a signal based on the control signal to at least one of the first counter vibration electrode or the second counter vibration electrode in the second mode operation.
The sensor according to any one of Configurations 7 to 9, wherein
the controller supplies the third mode signal to at least one of the first counter vibration electrode or the second counter vibration electrode in the third mode operation.
A sensor, comprising:
The sensor according to Configuration 12, wherein
The sensor according to Configuration 13, wherein
The sensor according to Configuration 14, wherein
The sensor according to Configuration 15, wherein
The sensor according to any one of Configurations 1 to 16, further comprising:
The sensor according to Configuration 17, wherein
An electronic device; comprising:
According to the embodiment, a sensor and an electronic device can be provided in which accuracy can be improved.
Hereinabove, exemplary embodiments of the invention are described with reference to specific examples. However, the embodiments of the invention are not limited to these specific examples. For example, one skilled in the art may similarly practice the invention by appropriately selecting specific configurations of components included in sensors such as sensor elements, sensor parts, movable parts, fixed parts, supporters, base bodies, controllers, etc., from known art. Such practice is included in the scope of the invention to the extent that similar effects thereto are obtained.
Further, any two or more components of the specific examples may be combined within the extent of technical feasibility and are included in the scope of the invention to the extent that the purport of the invention is included.
Moreover, all sensors practicable by an appropriate design modification by one skilled in the art based on the sensors described above as embodiments of the invention also are within the scope of the invention to the extent that the purport of the invention is included.
Various other variations and modifications can be conceived by those skilled in the art within the spirit of the invention, and it is understood that such variations and modifications are also encompassed within the scope of the invention.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the invention.
Number | Date | Country | Kind |
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2021-187034 | Nov 2021 | JP | national |