JP2010223854A - Three-axis detection angular velocity sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a three-axis detection angular velocity sensor that accurately detects angular velocities in an X-axis direction, a Y-axis direction and a Z-axis direction in such a manner that a driving signal in the Y-axis direction and a detection signal by a Coriolis force in the Y-axis direction generated by driving in the Z-axis direction and an angular velocity around an X axis do not have the same phases. <P>SOLUTION: A driving circuit 49 is provided with a phase shift circuit 55b. A driving signal for driving of vibration in the Z-axis direction and a driving signal for driving of vibration in the Y-axis direction have phases different from each other by an angle except 90 degrees. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  In particular, the present invention relates to a triaxial detection angular velocity sensor capable of detecting angular velocities in the triaxial directions of the X axis, the Y axis, and the Z axis.

  Conventional three-axis detection angular velocity sensors of this type are configured as shown in FIGS.

  FIG. 13 is a side sectional view of a conventional triaxial detection angular velocity sensor, and FIG. 14 is a top view of the triaxial detection angular velocity sensor.

  13 and 14, reference numeral 1 denotes a rectangular parallelepiped mass portion made of Si. And this mass part 1 is comprised so that the resonant frequency of a X-axis direction and a Y-axis direction may become substantially the same. Reference numeral 2 denotes a support member made of Si, the inner periphery and the outer periphery of which are octagonal and extended over the entire periphery. The support member 2 supports the mass portion 1 from the entire outer periphery, and a plurality of support members on the upper surface. An outer drive piezoelectric body 3 and an inner drive piezoelectric body 4 made of PZT are provided. An outer detection piezoelectric member 5 and an inner detection piezoelectric member 6 are provided on the upper surface of the support member 2 between the outer drive piezoelectric member 3 and the inner drive piezoelectric member 4. Reference numeral 7 denotes a rectangular cylindrical frame made of Si. The frame 7 integrally supports the support member 2.

  Next, the operation of the conventional three-axis detection angular velocity sensor configured as described above will be described.

  When an AC voltage having a phase difference of 90 degrees between the Z-axis direction and the Y-axis direction as shown in FIGS. 15A and 15B is applied to the outer drive piezoelectric body 3 and the inner drive piezoelectric body 4 in the support member 2. As shown in FIGS. 16A to 16D, the vibrator 1 is driven in a circular vibration so that the phase difference between the Z-axis direction and the Y-axis direction is 90 degrees. In this state, when an angular velocity is generated around the X axis, Y axis, and Z axis of the vibrator 1, F = 2 mV × in the direction perpendicular to both the direction in which the vibrator 1 is driven to vibrate and the direction in which the angular speed is generated. ω Coriolis force is generated. Then, the electric charges generated from the outer detection piezoelectric member 5 and the inner detection piezoelectric member 6 are IV-converted by this Coriolis force, and then detected synchronously to detect angular velocities in the X axis direction, the Y axis direction, and the Z axis direction. Met.

As prior art document information relating to the invention of this application, for example, Patent Document 1 is known.
JP-A-8-145683

  However, in the conventional configuration described above, the phase difference between the drive signal that is driven to vibrate in the Z-axis direction and the drive signal that is driven to vibrate in the Y-axis direction is 90 degrees, and therefore the Y-axis direction shown in FIG. The drive signal and the detection signal based on the Coriolis force in the Y-axis direction generated by the angular velocity around the X-axis and driven in the Z-axis direction shown in FIG. 17B are in the same phase as shown in FIG. Therefore, it is difficult to separate the signals, thereby causing a problem that the angular velocities in the X-axis direction, the Y-axis direction, and the Z-axis direction cannot be accurately detected.

  The present invention solves the above-described conventional problem, and the drive signal in the Y-axis direction and the detection signal based on the Coriolis force in the Y-axis direction generated by the angular velocity around the X-axis driven in the Z-axis direction have the same phase. It is an object of the present invention to provide a triaxial detection angular velocity sensor that can accurately detect angular velocities in the X axis direction, the Y axis direction, and the Z axis direction.

  In order to achieve the above object, the present invention has the following configuration.

  According to a first aspect of the present invention, a mass part that is displaceable in the three-axis directions of the X axis, the Y axis, and the Z axis, the mass part that supports the mass part, and at least a pair of drive piezoelectric bodies and at least one detection Detection on the support member by a support member provided with a piezoelectric body and at least one monitor piezoelectric body, a drive circuit that vibrates and drives the mass portion in the Y-axis direction and the Z-axis direction, and an angular velocity added to the mass portion A detection circuit that detects an output signal generated in the piezoelectric body, and a phase shift circuit is provided in the drive circuit so that a drive signal for driving vibration in the Z-axis direction and a drive signal for driving vibration in the Y-axis direction are other than 90 degrees. According to this configuration, a phase shift circuit is provided in the drive circuit, and a drive signal for driving vibration in the Z-axis direction and a drive signal for driving vibration in the Y-axis direction are provided. Since the phase differences are different from each other other than 0 degrees, phase detection can be performed with different phases, and accordingly, the drive signal in the Y-axis direction, the drive in the Z-axis direction, and the angular velocity around the X-axis Since the generated detection signal due to the Coriolis force in the Y-axis direction does not have the same phase, it is possible to separate the signals by phase detection, and as a result, in the X-axis direction, the Y-axis direction, and the Z-axis direction. This has the effect of being able to accurately detect the angular velocity.

  According to a second aspect of the present invention, there is provided a mass part that is displaceable in the three axial directions of the X-axis, Y-axis, and Z-axis, and supports the mass part, extends in the X-axis direction, and is at least on the upper surface. An X-axis direction support member provided with one detection piezoelectric body; and at least a pair of drive piezoelectric bodies, at least one detection piezoelectric body and at least one monitor that support the mass portion and extend in the Y-axis direction on the upper surface. A Y-axis support member provided with a piezoelectric body, a drive circuit that vibrates and drives the mass part in the Y-axis direction and the Z-axis direction, and an angular velocity added to the mass part, depending on the X-axis direction support member or the Y-axis A detection circuit for detecting an output signal generated in one or both of the direction support members, a drive signal provided with a phase shift circuit in the drive circuit, and driven to vibrate in the Z-axis direction; Y-axis direction The drive signal to be driven to vibrate has a different phase other than 90 degrees. According to this configuration, the drive circuit is provided with a phase shift circuit, and the drive signal to be driven to vibrate in the Z-axis direction and the Y-axis direction. Since the phase difference between the driving signal and the driving signal to be vibrated is different from that other than 90 degrees, phase detection can be performed with a different phase. As a result, the driving signal in the Y-axis direction and the driving signal in the Z-axis direction can be detected. And the detection signal due to the Coriolis force in the Y-axis direction generated by the angular velocity around the X-axis does not have the same phase, so that the signal can be separated by phase detection. This has the effect of being able to accurately detect the angular velocities in the Y-axis direction and the Z-axis direction.

  According to the third aspect of the present invention, in particular, the phase shift circuit causes the drive signal for driving vibration in the Y-axis direction to be delayed or advanced by about 45 degrees from the drive signal for driving vibration in the Z-axis direction. According to this configuration, since the drive signal for driving the vibration in the Y-axis direction is delayed or advanced by about 45 degrees from the drive signal for driving the vibration in the Z-axis direction by the phase shift circuit, the detection signal When the unnecessary signal generated in the phase detection is phase-detected, there is an effect that it can be surely removed.

  As described above, the three-axis detection angular velocity sensor of the present invention includes a mass part that can be displaced in the three-axis directions of the X-axis, the Y-axis, and the Z-axis, and supports at least one pair of driving piezoelectric bodies and at least one. A support member provided with two detection piezoelectric bodies and at least one monitor piezoelectric body; a drive circuit that vibrates and drives the mass section in the Y-axis direction and the Z-axis direction; and an angular velocity added to the mass section. And a detection circuit for detecting an output signal generated in the detection piezoelectric body, and a phase shift circuit is provided in the drive circuit so that a drive signal for driving vibration in the Z-axis direction and a drive signal for driving vibration in the Y-axis direction are 90. In this configuration, the phase shift circuit is provided in the drive circuit to drive the drive signal in the Z-axis direction and the drive signal in the Y-axis direction. Since the phase difference between the motion signal and the moving signal is different from each other other than 90 degrees, phase detection can be performed with a different phase, whereby the drive signal in the Y-axis direction, the drive in the Z-axis direction, and the X-axis Since the detection signal due to the Coriolis force in the Y-axis direction generated by the surrounding angular velocity does not have the same phase, it is possible to separate the signals by phase detection. As a result, the X-axis direction, the Y-axis direction, and This has the effect of providing a three-axis detection angular velocity sensor that can accurately detect the angular velocity in the Z-axis direction.

  Hereinafter, a three-axis detection angular velocity sensor according to an embodiment of the present invention will be described with reference to the drawings.

  1 is a side sectional view of a triaxial detection angular velocity sensor according to an embodiment of the present invention, FIG. 2 is a top view of the triaxial detection angular velocity sensor, and FIG. 3 is a first X-axis direction of the triaxial detection angular velocity sensor. FIG. 4 is a circuit diagram of the triaxial detection angular velocity sensor.

  1-4, 21 is a rectangular parallelepiped mass part which consists of Si. Reference numeral 22 denotes a first X-axis direction support member made of Si. The first X-axis direction support member 22 supports an upper portion of one side surface of the mass portion 21 and a pair of PZTs on the outer side of the upper surface. An outer drive piezoelectric body 23 is provided, and an inner drive piezoelectric body 24 made of a pair of PZTs is provided inside the upper surface. Further, on the upper surface of the first X-axis direction support member 22, an outer detection piezoelectric member 25 is provided between the pair of outer drive piezoelectric members 23. An inner detection piezoelectric body 26 is provided between them.

  Reference numeral 27 denotes a second X-axis direction support member made of Si. The second X-axis direction support member 27 is on the opposite side of the mass portion 21 from the side on which the first X-axis direction support member 22 is provided. While supporting the upper part of one side, the outer side drive piezoelectric material 28 which consists of a pair of PZT is provided in the outer side of the upper surface, and the inner side drive piezoelectric material 29 which consists of a pair of PZT is further provided inside the upper surface. Further, on the upper surface of the second X-axis direction support member 27, an outer detection piezoelectric body 30 is provided between the pair of outer drive piezoelectric bodies 28. The inner detection piezoelectric body 31 is provided between them.

  Reference numeral 32 denotes a first Y-axis direction support member made of Si. The first Y-axis direction support member 32 supports the upper part of one side surface of the mass portion 21 and is made of a pair of PZTs on the outer side of the upper surface. An outer drive piezoelectric body 33 is provided, and an inner drive piezoelectric body 34 made of a pair of PZTs is provided inside the upper surface. Further, on the upper surface of the first Y-axis direction support member 32, an outer detection piezoelectric body 35 is provided between the pair of outer drive piezoelectric bodies 33. An inner detection piezoelectric body 36 is provided between them. Further, on the upper surface of the first Y-axis direction support member 32, an outer monitor piezoelectric body 37 is provided outside the outer drive piezoelectric body 33 and is positioned outside the inner drive piezoelectric body 34. An inner monitor piezoelectric body 38 is provided.

  39 is a second Y-axis direction support member made of Si, and this second Y-axis direction support member 39 is on the opposite side of the mass portion 21 from the side where the first Y-axis direction support member 32 is provided. While supporting the upper part of one side, the outer side drive piezoelectric material 40 which consists of a pair of PZT is provided in the outer side of the upper surface, and the inner side drive piezoelectric material 41 which consists of a pair of PZT is further provided inside the upper surface. Further, on the upper surface of the second Y-axis direction support member 39, an outer detection piezoelectric body 42 is provided between the pair of outer drive piezoelectric bodies 40, and the inner drive piezoelectric body 41 is further provided. An inner detection piezoelectric body 43 is provided between them. Further, on the upper surface of the second Y-axis direction support member 39, a pair of inner monitor piezoelectric bodies 70 are provided outside the pair of inner drive piezoelectric bodies 41.

  Further, as shown in FIG. 3, the outer drive piezoelectric body 23 and the outer detection piezoelectric body 25 located on the upper surface of the first X-axis direction support member 22 are formed of the first X-axis direction support member 22 made of Si. Provided on the upper surface of the common GND electrode 44 made of an alloy thin film of Pt and Ti provided on the upper surface, and provided with a drive electrode 45 on the upper surface of the outer drive piezoelectric member 23 and a detection electrode on the upper surface of the outer detection piezoelectric member 25. 46 is provided. The mass portion 21 is supported by the first X-axis direction support member 22, the second X-axis direction support member 27, the first Y-axis direction support member 32, and the second Y-axis direction support member 39. Thus, the drive frequencies in the X-axis direction, the Y-axis direction, and the Z-axis direction are each set to 40 kHz. The first X-axis direction support member 22, the second X-axis direction support member 27, the first Y-axis direction support member 32, and the second Y-axis direction support member 39 are as shown in FIG. In addition, there are four holes 71 between them, an outer peripheral portion 72 integrally connected on the outer peripheral side, and a processing circuit 48 made of an IC is provided on the upper surface of the outer peripheral portion 72.

  Reference numeral 47 denotes a rectangular cylindrical frame made of Si. The frame 47 includes the first X-axis direction support member 22, the second X-axis direction support member 27, the first Y-axis direction support member 32, and the first X-axis direction support member 32. The outer peripheral portion 72 connected to the two Y-axis direction support members 39 is supported.

  The processing circuit 48 provided on the upper surface of the outer peripheral portion 72 includes the outer driving piezoelectric bodies 23, 28, 33, 40, the inner driving piezoelectric bodies 24, 29, 34, 41, and the outer detection piezoelectric bodies 25, 30, 35, 42. And the inner detection piezoelectric bodies 26, 31, 36, 43 are electrically connected to each other by a circuit pattern (not shown), and an output signal from the processing circuit 48 is passed through a circuit pattern (not shown). The output is to an external circuit (not shown).

  Further, as shown in FIG. 4, the processing circuit 48 includes a drive circuit 49 and a detection circuit 50, and the drive circuit 49 includes a Z-axis direction drive circuit 51a and a Y-axis direction drive circuit 51b. It is what has been. Further, the Z-axis direction drive circuit 51a performs differential output signals from the outer monitor piezoelectric body 37 in the first Y-axis direction support member 32 and the inner monitor piezoelectric body 70 in the second Y-axis direction support member 39. The values are passed through the IV converter 52, the bandpass filter 53 and the AGC circuit 54 in the Z-axis direction drive circuit 51a, and the drive signals are sent to the outer drive piezoelectric bodies 23, 28, 33, 40 and the inner drive piezoelectric bodies 24, 29, 34. , 41, the mass portion 21 is driven to vibrate with a constant amplitude in the Z-axis direction. Similarly, the Y-axis direction drive circuit 51b in the drive circuit 49 includes a multiplier 55a and a drive phase shift circuit 55b, and an output from the AGC circuit 54 in the Z-axis direction drive circuit 51a. After the signal is multiplied by a constant by the multiplier 55a, the phase is delayed by 45 degrees by the driving phase shift circuit 55b and input to the outer driving piezoelectric bodies 33 and 40 and the inner driving piezoelectric bodies 34 and 41, so that the mass part 21 is driven and oscillated with a constant amplitude in the Y-axis direction. Further, a first detection phase shift circuit 56 and a second detection phase shift circuit 57 are provided in parallel at the subsequent stage of the band-pass filter 53 in the Z-axis direction drive circuit 51a, and the first detection phase shift circuit 57 is provided. The phase shift circuit outputs a signal obtained by delaying the output signal from the bandpass filter 53 by 45 degrees, and the second detection phase shift circuit 57 outputs a signal delayed by 135 degrees.

  The detection circuit 50 includes a Y-direction Coriolis force detection circuit 58 and an X-direction Coriolis force detection circuit 59. The Y-direction Coriolis force detection circuit 58 is outside the first Y-axis direction support member 32. The output signals of the detection piezoelectric member 35 and the inner detection piezoelectric member 36 are input to the IV converter 60, and the output signals of the outer detection piezoelectric member 42 and the inner detection piezoelectric member 43 in the second Y-axis direction support member 39 are IV converted. After being input to the detector 61 and taking the difference between the two, the synchronous detector 62 performs phase detection based on the output signal from the second detection phase shift circuit 57 and then smoothes it by the low-pass filter 63. The angular velocity around the X axis is detected. The X-direction Coriolis force detection circuit 59 includes an IV converter 64 for inputting output signals of the outer detection piezoelectric body 25 and the inner detection piezoelectric body 26 in the first X-axis direction support member 22, and a second X-axis. The differential value of the output signal from the IV converter 65 that inputs the output signals from the outer detection piezoelectric member 30 and the inner detection piezoelectric member 31 in the direction support member 27 is converted into a first detection phase shift by the synchronous detector 66. The phase velocity is detected by using the output signal from the circuit 56 as a reference and then smoothed by a low-pass filter 67 to detect the angular velocity around the Y axis. Further, similarly to these, the synchronous detector 68 performs phase detection on the basis of the direct output signal from the bandpass filter 53 in the Z-axis direction drive circuit 51a as a reference, and then smoothes it by the low-pass filter 69, whereby the Z-axis The angular velocity around is detected.

  Next, a method for assembling the three-axis detection angular velocity sensor according to the embodiment of the present invention configured as described above will be described.

  First, a common GND electrode 44 made of an alloy thin film of Pt and Ti is formed by vapor deposition on the upper surface of a substrate (not shown) made of Si prepared in advance, and then made of a PZT thin film on the upper surface of the common GND electrode 44. Outer drive piezoelectric elements 23, 28, 33, 40, inner drive piezoelectric elements 24, 29, 34, 41, outer detection piezoelectric elements 25, 30, 35, 42, inner detection piezoelectric elements 26, 31, 36, 43, outer monitor The piezoelectric body 37 and the inner monitor piezoelectric bodies 38 and 70 are formed by vapor deposition.

  Next, the outer drive piezoelectric members 23, 28, 33, 40, the inner drive piezoelectric members 24, 29, 34, 41, the outer detection piezoelectric members 25, 30, 35, 42, the inner detection piezoelectric members 26, 31, 36, 43. The drive electrode 45, the detection electrode 46, and the monitor electrode (not shown) made of an alloy thin film of Ti and Au are formed on the upper surfaces of the outer monitor piezoelectric member 37 and the inner monitor piezoelectric members 38 and 70.

  Next, while applying a voltage to the common GND electrode 44 side and grounding the drive electrode 45, the detection electrode 46, and the monitor electrode (not shown), the outer drive piezoelectric bodies 23, 28, 33, 40, the inner drive Piezoelectric bodies 24, 29, 34, 41, outer detection piezoelectric bodies 25, 30, 35, 42, inner detection piezoelectric bodies 26, 31, 36, 43, outer monitor piezoelectric bodies 37, and inner monitor piezoelectric bodies 38, 70 are polarized. .

  Finally, by removing unnecessary portions in the base material (not shown), the mass portion 21, the first X-axis direction support member 22, the second X-axis direction support member 27, and the first Y-axis direction After forming the support member 32, the second Y-axis direction support member 39, the outer peripheral portion 72, and the frame body 47, a processing circuit 48 made of IC is soldered to a circuit pattern (not shown).

  Next, the operation of the three-axis detection angular velocity sensor according to the embodiment of the present invention constructed and assembled as described above will be described.

  First, a case where an angular velocity around the X axis is first added to the mass portion 21 will be described.

  When a positive voltage is applied to the inner driving piezoelectric bodies 24, 29, 34, and 41 and a negative voltage is applied to the outer driving piezoelectric bodies 23, 28, 33, and 40, as shown in FIG. 29, 34, and 41 extend, and the outer drive piezoelectric bodies 23, 28, 33, and 40 contract, and as a result, the mass portion 21 moves upward. Next, when a negative voltage is applied to the inner drive piezoelectric bodies 24, 29, 34, and 41 and a positive voltage is applied to the outer drive piezoelectric bodies 23, 28, 33, and 40, the inner drive piezoelectric bodies 24, 29, 34, and 41 shrinks and the outer drive piezoelectric bodies 23, 28, 33, and 40 extend, and as a result, the mass portion 21 moves downward. That is, by applying an AC voltage composed of a sine wave as shown in FIG. 6A to the outer drive piezoelectric bodies 23, 28, 33, and 40 and the inner drive piezoelectric bodies 24, 29, 34, and 41, 21 is a vibration drive at a speed V at a drive frequency in the Z-axis direction. The vibration drive of the mass portion 21 causes the inner drive piezoelectric bodies 24, 29, 34, 41 and the outer drive piezoelectric body 23 so that output signals generated from the outer monitor piezoelectric body 37 and the inner monitor piezoelectric body 70 are constant. , 28, 33, and 40 are adjusted to control the amplitude of vibration drive.

  Similarly, the mass unit 21 is also driven to vibrate in the Y-axis direction. That is, a positive voltage is applied to the outer drive piezoelectric body 33 and the inner drive piezoelectric body 34 in the first Y-axis direction support member 32, and at the same time, the outer drive piezoelectric body 40 and the inner drive piezoelectric element in the second Y-axis direction support member 39. When a negative voltage is applied to the body 41, the outer driving piezoelectric member 33 and the inner driving piezoelectric member 34 are extended, and the outer driving piezoelectric member 40 and the inner driving piezoelectric member 41 are contracted. It moves toward the Y-axis direction support member 32.

  Next, a negative voltage is applied to the outer drive piezoelectric body 33 and the inner drive piezoelectric body 34 in the first Y-axis direction support member 32, and at the same time, the outer drive piezoelectric body 40 and the inner drive in the second Y-axis direction support member 39. When a positive voltage is applied to the piezoelectric body 41, the outer driving piezoelectric body 33 and the inner driving piezoelectric body 34 contract, and the outer driving piezoelectric body 40 and the inner driving piezoelectric body 41 extend, and as a result, the mass unit 21 has the second portion. It moves toward the Y-axis direction support member 39. That is, the driving phase shift circuit 55b applies an AC voltage composed of a sine wave as shown in FIG. 6 (b) delayed by 45 degrees from FIG. 6 (a) to the outer driving piezoelectric bodies 23, 28, 33, 40 and the inner drive piezoelectric bodies 24, 29, 34, 41 are applied so that the mass portion 21 is driven to vibrate at a speed V at a drive frequency in the Y-axis direction. Actually, the mass unit 21 is driven so as to draw an elliptical orbit on the YZ plane. The vibration drive of the mass unit 21 is such that the output signals generated from the inner monitor piezoelectric members 38 and 70 are constant, the outer drive piezoelectric member 33, the inner drive piezoelectric member 34, the outer drive piezoelectric member 40, and the inner drive piezoelectric member 41. The amplitude of the vibration drive is controlled by adjusting the voltage applied to.

  Further, when the mass unit 21 rotates at an angular velocity ω around the central axis in the X-axis direction in a state where the mass unit 21 is driven to vibrate at a drive frequency in the Z-axis direction, as shown in FIG. 21 generates a Coriolis force of F = 2 mV × ω in the Y-axis direction. Due to this Coriolis force, the mass portion 21 is driven to vibrate in the Y-axis direction. Therefore, as shown in FIG. 8, for example, as shown in FIG. A positive charge is generated by the expansion of the piezoelectric body 36, and a negative charge is generated by the contraction of the outer detection piezoelectric element 42 and the inner detection piezoelectric element 43 in the second Y-axis direction support member 39. The electric charges generated from the outer detection piezoelectric member 35 and the inner detection piezoelectric member 36 are converted into output signals by the IV converter 60, and the electric charges generated from the outer detection piezoelectric member 42 and the inner detection piezoelectric member 43 are converted into the IV converter 61. The output signal shown in FIG. 9B is generated by converting the output signal into the output signal and taking the difference between the two. At this time, as described above, since the mass portion 21 is driven and oscillated in the Y-axis direction, the outer detection piezoelectric body 42 and the inner detection piezoelectric body 43 have the same waveform as FIG. ) Is also generated, and the output signal shown in FIG. 9C, which is a combination of FIG. 9A and FIG. 9B, is output. Then, the synchronous detector 62 performs phase detection using the second detection phase shift circuit 57 as a reference signal, so that the signal component shown in FIG. 9B becomes as shown in FIG. The output signal shown in 9 (a) is as shown in FIG. 9 (f). Therefore, by smoothing with the low-pass filter 63, the signal shown in FIG. 9F becomes a zero value, and only the angular velocity component around the X axis can be detected.

  Next, a case where an angular velocity around the Y axis is added to the mass unit 21 will be described. Also in this case, as in the case where the angular velocity around the X axis is detected, the mass portion 21 is angularly rotated around the central axis in the Y axis direction when the mass portion 21 is driven to vibrate in the Z axis direction. As shown in FIG. 10, a Coriolis force of F = 2 mV × ω in the X-axis direction is generated in the mass portion 21 as shown in FIG. Due to this Coriolis force, the mass portion 21 is driven to vibrate in the X-axis direction, so that the outer detection piezoelectric member 23 and the inner detection piezoelectric member 25 in the first X-axis direction support member 22 are extended by this vibration drive. Is generated, and the outer detection piezoelectric member 30 and the inner detection piezoelectric member 31 of the second X-axis direction support member 27 are contracted to generate a negative charge. The electric charge generated from the outer detection piezoelectric member 23 and the inner detection piezoelectric member 26 is converted into an output signal by the IV converter 64, and the electric charge generated from the outer detection piezoelectric member 30 and the inner detection piezoelectric member 31 is converted into the IV converter 65. The output signal shown in FIG. 11A is generated by converting the signal into an output signal and taking the difference between the two.

  Next, a case where an angular velocity around the Z axis is added to the mass portion 21 will be described. When the mass unit 21 is driven to vibrate in the Y-axis direction and the mass unit 21 rotates at the angular velocity ω around the central axis in the Z-axis direction, as shown in FIG. A Coriolis force of F = 2 mV × ω is generated. Due to the Coriolis force, the mass portion 21 is driven to vibrate in the X-axis direction, so that the outer detection piezoelectric body 25 and the inner detection piezoelectric body 26 in the first X-axis direction support member 22 are extended by the vibration drive, thereby causing positive charge. Is generated, and the outer detection piezoelectric member 30 and the inner detection piezoelectric member 31 of the second X-axis direction support member 27 are contracted to generate a negative charge. The electric charges generated from the outer detection piezoelectric member 25 and the inner detection piezoelectric member 26 are converted into output signals by the IV converter 64, and the electric charges generated from the outer detection piezoelectric member 30 and the inner detection piezoelectric member 31 are converted into the IV converter 65. The output signal shown in FIG. 11B is output with the phase delayed by 45 degrees from that in FIG. 11A. Therefore, the output signal shown in FIG. 11C obtained by synthesizing FIG. 11A and FIG. 11B is actually output as the differential output signal. Then, the output signal from the bandpass filter 53 in the Z-axis direction drive circuit 51a is phase-detected by the synchronous detector 68 using FIG. 11 (d) as a reference signal, so that the signal components shown in FIG. On the other hand, as shown in FIG. 11E, the output signal shown in FIG. 11B is as shown in FIG. Therefore, by smoothing with the low-pass filter 69, the signal shown in FIG. 11E becomes a zero value, and only the angular velocity component around the Z axis can be detected.

  Further, when the synchronous detector 66 performs phase detection using the output signal from the first detection phase shift circuit 56 shown in FIG. 11G as a reference signal, the signal component shown in FIG. On the other hand, the output signal shown in FIG. 11 (b) is as shown in FIG. 11 (i). Therefore, by smoothing with the low-pass filter 67, the signal shown in FIG. 11 (i) becomes a zero value, and only the angular velocity component around the Y axis can be detected.

  In the three-axis detection angular velocity sensor according to the embodiment of the present invention, the drive signal for driving vibration in the Y-axis direction by the driving phase shift circuit 55b is approximately 45 degrees from the drive signal for driving vibration in the Z-axis direction. Although it is configured to delay, the same effect can be achieved by a configuration that advances about 45 degrees.

  In the three-axis detection angular velocity sensor according to the present invention, the drive signal in the Y-axis direction and the detection signal due to the Coriolis force in the Y-axis direction generated by the angular velocity around the X-axis driven in the Z-axis direction have the same phase. It is possible to provide a three-axis detection angular velocity sensor that can accurately detect the angular velocities in the X-axis direction, the Y-axis direction, and the Z-axis direction. The present invention is useful when applied to a three-axis detection angular velocity sensor capable of detecting an axial angular velocity.

Side sectional view of a three-axis detection angular velocity sensor in one embodiment of the present invention Top view of the 3-axis detection angular velocity sensor Side sectional view of the first X-axis direction support member in the same three-axis detection angular velocity sensor Circuit diagram of the 3-axis detection angular velocity sensor Side sectional view showing a state in which the 3-axis detection angular velocity sensor is driven to vibrate in the Z-axis direction The figure which shows the signal which drives the same 3 axis detection angular velocity sensor The figure which shows the state which detects the angular velocity around the X-axis of the same 3-axis detection angular velocity sensor Side sectional view showing a state in which the three-axis detection angular velocity sensor is operated by the Coriolis force in the Y-axis direction. The figure which shows an output signal when the same 3 axis detection angular velocity sensor operates The figure which shows the state which detects the angular velocity around the Y-axis of the same 3-axis detection angular velocity sensor The figure which shows an output signal when the same 3 axis detection angular velocity sensor operates The figure which shows the state which detects the angular velocity around the Z-axis of the same 3-axis detection angular velocity sensor Side sectional view of a conventional 3-axis detection angular velocity sensor Top view of the 3-axis detection angular velocity sensor The figure which shows the signal which drives the conventional 3-axis detection angular velocity sensor The figure which shows the state which the conventional 3 axis | shaft detection angular velocity sensor operate | moves. The figure which shows an output signal when the conventional 3-axis detection angular velocity sensor operate | moves

21 Mass part 22, 27 X-axis direction support member 23, 24, 28, 29, 33, 34, 40, 41 Drive piezoelectric body 25, 26, 30, 31, 35, 36, 42, 43 Detection piezoelectric body 32, 39 Y-axis direction support member 37, 38, 70 Monitor piezoelectric body 49 Drive circuit 50 Detection circuit 55b Phase shift circuit

Claims (3)

A mass part that is displaceable in the X-axis, Y-axis, and Z-axis directions, and at least one drive piezoelectric element, at least one detection piezoelectric element, and at least one monitor piezoelectric element are provided to support the mass part. A support circuit, a drive circuit that vibrates and drives the mass part in the Y-axis direction and the Z-axis direction, and a detection circuit that detects an output signal generated in the detection piezoelectric body in the support member by an angular velocity added to the mass part The drive circuit is provided with a phase shift circuit so that the drive signal for driving vibration in the Z-axis direction and the drive signal for driving vibration in the Y-axis direction have different phase differences other than 90 degrees. Axis detection angular velocity sensor. An X-axis direction support that supports a mass part that is displaceable in the X-axis, Y-axis, and Z-axis directions, and that supports the mass part and that extends in the X-axis direction and is provided with at least one detection piezoelectric body on the upper surface. A member, and a Y-axis direction support member that supports the mass portion and extends in the Y-axis direction, and includes at least a pair of drive piezoelectric bodies, at least one detection piezoelectric body, and at least one monitor piezoelectric body on the upper surface. The drive circuit that vibrates and drives the mass unit in the Y-axis direction and the Z-axis direction, and the angular velocity applied to the mass unit, either or both of the X-axis support member and the Y-axis support member A detection circuit for detecting an output signal generated in the detection piezoelectric body, a phase shift circuit is provided in the drive circuit, and a drive signal for driving vibration in the Z-axis direction and a drive signal for driving vibration in the Y-axis direction are 90 3 axis detecting angular velocity sensor configured as a different phase other than. 2. The three-axis detection angular velocity sensor according to claim 1, wherein a drive signal for vibration driving in the Y-axis direction is delayed or advanced by about 45 degrees from a drive signal for vibration driving in the Z-axis direction by a phase shift circuit.

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