JP2005140708A - Electrostatic levitation-type gyro device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To combine advantages without causing both improvements to spoil each other even if a signal detection circuit is improved so that the amplitude voltage of an application signal for detecting displacement is increased without sacrificing a control voltage, and a control circuit is improved so that a supply voltage is utilized efficiently and control capacity is improved. <P>SOLUTION: A voltage signal V0 for detecting displacement is applied to electrodes 38, 48 for detecting displacement, and is divided when it is transmitted to a plurality of control electrodes 31-37, 41-47 through a gyro rotor 10, and is detected by in-phase detection circuit 92+93 attached to it, when the voltage signal reaches the output side of an output circuit 108 of each corresponding control output circuit 104. Additionally, control voltages V1a, V1b are subjected to pulse wave modulation, and the pulse end is overlapped to the sudden change point of the voltage signal V0 for detecting displacement. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to an electrostatic levitation gyro apparatus including a gyro mechanism and an electronic circuit.
The gyro mechanism unit includes a gyro rotor and a gyro case, and supports the gyro rotor in a floating manner in the gyro case by electrostatic support force. The gyro rotor is placed in a vacuum for proper operation.
The electronic circuit unit is connected to the gyro mechanism unit, detects the relative displacement between the gyro rotor and the gyro case, and performs attitude control and rotational driving of the gyro rotor.
More specifically, the present invention relates to a signal detection circuit that detects the displacement and a control voltage output method in a control circuit that generates a control voltage for posture control and rotation driving.

[Prerequisite technology]
Electrostatic levitation type gyro suitable for miniaturization is used not only for ships and aircraft but also for moving objects such as automobiles, and for detecting acceleration etc. with respect to inertial space, it is composed of mechanical parts with inertia. And an electronic circuit unit for controlling electrostatic support force and detecting relative displacement.
FIG. 17 shows two gyro mechanism parts in such an electrostatic levitation gyro. (A) to (c) are known examples of the disk-shaped rotor type (see, for example, Patent Document 1), and (d) and (e) are known examples of the annular rotor type (for example, Patent Document 2). In the figure, (a) and (d) are longitudinal sectional front views, and (b), (c) and (e) are developed perspective views of built-in components.

  When the portions that are the premise of the implementation and description of the present invention are scratched and reprinted, the gyro rotor 10 is built in the gyro case 20 in a state where the gyro rotor 10 can be electrostatically levitated and rotated. The gyro case 20 is configured by combining an upper bottom member 21, a lower bottom member 22, and a spacer 23 made of an insulating material such as glass, and a disk-like or annular vacuum space is formed therein. The gyro rotor 10 is made of a conductor such as silicon, and is formed in a disk shape or in an annular shape so as to rotate stably around one spin axis. In order to apply an electrostatic supporting force and a rotational driving force from the gyro case 20 to the gyro rotor 10, a large number of electrodes made of a metal film pattern or the like are formed on the surfaces of both. The electrodes of the gyro rotor 10 and the electrodes of the gyro case 20 are arranged so as to satisfy a predetermined correspondence relationship such as a facing distance and a pitch according to their roles.

  The electrodes (multiple electrodes) of the gyro case 20 connected to the electronic circuit will be described in detail. The gyro case 10 is divided into a plurality of pairs opposed to each other with the gyro rotor 10 interposed therebetween. In particular, the electrodes for electrostatic support are further divided into groups and pairs arranged adjacent to each other. Specifically, the adjacent electrodes 31a and 31b and the adjacent electrodes 41a and 41b form an opposing pair, the adjacent electrodes 32a and 32b and the adjacent electrodes 42a and 42b form an opposing pair, and the adjacent electrodes 33a and 33b and the adjacent electrode 43a. , 43b form a counter pair, and the adjacent electrodes 34a, 34b and the adjacent electrodes 44a, 44b form a counter pair. In the case of the annular rotor type, there are many pairs of electrostatic support electrodes, the adjacent electrodes 35a and 35b and the adjacent electrodes 45a and 45b form an opposing pair, and the adjacent electrodes 36a and 36b and the adjacent electrodes 46a and 46b also face each other. Paired.

In addition, among the plurality of electrodes, the rotation driving electrode includes a rotor driving electrode 37 arranged in a circle on the lower surface of the upper bottom member 21 and a rotor driving electrode 47 arranged in a circle on the upper surface of the lower bottom member 22. And make an opposing pair.
Also in the displacement detection electrode, the displacement detection electrode 38 and the displacement detection electrode 48 form an opposing pair.
In the figure, the electrodes provided on the upper bottom member 21 are denoted by reference numerals in the 30th order, and the electrodes provided on the lower bottom member 22 are denoted by reference numerals in the 40th order. Further, in other illustrations and explanations, when calling any one of them without distinguishing the adjacent electrodes 31a and 31b, or calling them together, they are referred to as electrodes 31 with the final alphabet omitted. The same applies to the other electrodes 32 and the like.

  Furthermore, with respect to the ring rotor type gyro mechanism that is relatively simple and clear (see FIGS. 17D and 17E), the specific roles of the electrostatic support electrodes 31 to 36 and 41 to 46 are described. explain. The three axes that are orthogonal in space are the X, Y, and Z axes, respectively. In FIG. 17D, the X axis is placed in the left-right direction of the paper surface, the Y axis is placed in a direction penetrating the paper surface, and the vertical direction of the paper surface. The Z axis is set, the rotation around the X axis is φ, and the rotation around the Y axis is θ. Then, the electrode 31 is applied with a control voltage to generate an electrostatic supporting force in the X direction according to the applied voltage, and changes the capacitance with the surface of the gyro rotor 10 according to the displacement of the gyro rotor 10 in the X direction. ing. The opposing electrode 41 is also applied with a control voltage to generate an X-direction electrostatic supporting force, and changes the capacitance with the surface of the gyro rotor 10 in accordance with the displacement of the gyro rotor 10 in the X direction. However, the electrode 31 has a reverse characteristic. The electrode pairs 32 and 42 perform the same function in the Y direction, the electrode pairs 33 and 43 perform the same function in the Z + φ direction, the electrode pairs 34 and 44 perform the same function in the Z + θ direction, 35 and 45 exhibit the same function in the Z-φ direction, and the electrode pairs 36 and 46 perform the same function in the Z-θ direction.

[Conventional technology]
FIG. 18A illustrates an electronic circuit that is connected to the plurality of electrodes 31 to 48 of the gyro case 20 and constitutes an electrostatic levitation type gyro together with the gyro mechanism. Here again, for the sake of clarity, the electronic circuit portion of the annular rotor type gyro is taken as a specific example, and a portion useful for comparison with the embodiment of the present invention is scratched and reprinted.
This electronic circuit includes a control arithmetic circuit 53 (control circuit) that constitutes a constraint control system together with the electrodes 31 to 36 and 41 to 46 for electrostatic support, and a rotor control that constitutes a rotor drive system together with the electrodes 37 and 47 for rotor drive. The circuit 52 (control circuit) and the signal detection circuit which comprises a displacement detection system with the displacement detection electrodes 38 and 48 are provided. In the drawing, the control output circuit 54 is clearly shown for the control arithmetic circuit 53, but the rotor control circuit 52 is omitted.

  The control arithmetic circuit 53 calculates the relative displacement of the gyro rotor 10 and the gyro case 20 other than around the Z axis, that is, the X-direction displacement ΔX, the Y-direction displacement ΔY, the Z-direction displacement ΔZ, the φ-direction displacement Δφ, and the θ-direction displacement Δθ. Perform known calculations to generate control voltages V1, V12, etc. for posture control and apply them to the electrostatic support electrodes 31-36, 41-46 among the plurality of electrodes 31-48, etc. Therefore, attitude control is performed to make those relative displacements zero. These relative displacements are detected from capacitance changes of the electrostatic support electrodes 31 to 36 and 41 to 46. Each control voltage V1, V12, etc. is amplified to a required level before being applied by a control output circuit 54 that outputs a positive voltage signal and a negative voltage signal obtained by inverting the positive voltage signal.

The rotor control circuit 52 also performs a known calculation from the rotation state around the Z axis of the gyro rotor 10 to generate a rotation drive control voltage, for example, a three-phase pulse signal, and outputs them to the rotor drive electrode 37. , 47 and the like, the rotation control for rotating the gyro rotor 10 at a constant speed is performed. The rotational state of the gyro rotor 10 is detected from the capacitance change of the rotor driving electrodes 37 and 47. These control voltages are also amplified to a required level before being applied by the control output circuit 54 or a similar output circuit.
Unlike the electrostatic support electrodes 31 to 36 and 41 to 46 and the rotor drive electrodes 37 and 47 to which such a control voltage is directly applied, the displacement detection electrodes 38 and 48 among the plurality of electrodes 31 to 48 are used. In contrast, a control voltage that affects the motion of the gyro rotor 10 is not applied.

  In order to detect the relative displacement between the gyro rotor 10 and the gyro case 20, the signal detection circuit uses the displacement detection application signals f1 to f12 having a high frequency so as not to affect the motion of the gyro rotor 10. An application signal supply circuit for applying the detection application signals f1 to f12 to a part of the plurality of electrodes 31 to 48, and the displacement detection application signals f1 to f12 after the displacement detection electrodes 38 and 48 are displaced. A current detection circuit 51 (detection signal generation circuit) that detects a signal component related to the detection application signals f1 to f12 and generates a displacement detection detection signal Vp is provided.

  Specifically, the application signal supply circuit generates displacement detection application signals f1 to f12 by combining five sine wave signals w1 to w5 having different frequencies so as to be discriminated based on a well-known relational expression. The displacement detection application signals f1 to f12 are applied not to the displacement detection electrodes 38 and 48 but to the electrostatic support electrodes 31 to 36 and 41 to 46. In addition, at this time, application is performed by superimposing displacement detection application signals f1 to f12 on the control voltages V1, V12, and the like on the output side of the control output circuit 54.

  In the annular rotor type, there are six opposing pairs of electrostatic support electrodes. Of these, the electrode pairs 31 and 41 will be described in detail (see FIG. 18B). The control voltage V1 is a positive voltage + V1 and a negative voltage -V1. Are generated in pairs, and the positive voltage + V1 is applied to the electrostatic support electrode 31b after superimposing the displacement detection application signal f1, and the negative voltage -V1 is applied to the adjacent electrostatic support after superimposing the same displacement detection application signal f1. Applied to the electrode 31a. The control voltage V12 is generated as a pair of a positive voltage + V12 and a negative voltage −V12. The positive voltage + V12 is applied to the electrostatic support electrode 41b after the displacement detection application signal f12 is superimposed, and the negative voltage −V12 is the same. After the displacement detection application signal f12 is superimposed, it is applied to the adjacent electrostatic support electrode 41a.

  On the other hand, the current detection circuit 51 (see FIG. 18A) is not connected to the control output circuit 54 side, but is connected to the displacement detection electrodes 38 and 48 among the plurality of electrodes 31 to 48. The current detection circuit 51 includes an amplifier for signal amplification and the like, and its input line is connected to the parallel connection point of the displacement detection electrodes 38 and 48. The displacement detection detection signal Vp output from the current detection circuit 51 is also sent to the rotor control circuit 52 and the input circuit of the control arithmetic circuit 53.

Here, referring to the input circuit of the displacement detection detection signal Vp in the control arithmetic circuit 53 (see FIG. 18C), the displacement detection detection signal Vp and the sine are connected to the subordinate connection circuit of the synchronous detector and the band pass filter. For example, the X-direction displacement ΔX is detected by inputting the wave signal w1 and extracting the component of the sine wave signal w1 from the detection signal Vp for displacement detection. The same applies to the other displacements ΔY, ΔZ, Δφ, Δθ.
The signal detection circuit detects the relative displacements ΔX, ΔY, ΔZ, Δφ, Δθ and the rotation state based on the capacitance changes of the control electrodes 31 to 37, 41 to 47. In addition, the gyro rotor 10 floats to the neutral position in the gyro case 20 and continues to rotate by the attitude control and the rotational drive of the control arithmetic circuit 53 and the rotor control circuit 52 that have received the input. Furthermore, based on them, the acceleration etc. which acted on the electrostatic levitation type gyro are calculated and detected.

  Although illustration is omitted, implementation of such a gyro apparatus will also be described. An electrostatic levitation type gyro apparatus including an electronic circuit and a gyro mechanism as described above is mounted on a printed circuit board or the like to establish an electrical connection. In this case, the printed circuit board on which the gyro case 20 is mounted is mounted. Part of the electronic circuit was also implemented. At that time, circuit portions such as the control output circuit 54 and the current detection circuit 51 that are directly connected to the electrodes 31 to 48 of the gyro case 20 are preferentially mounted on the same substrate. In addition, the preamplifier of the current detection circuit 51 may be mounted on the upper surface of the gyro case 20 or the like. In any case, the vacuum space remains in the gyro case 20, and the gyro mechanism and the electronic circuit are mounted in the atmosphere. Moreover, in order to ensure a vacuum state in the gyro rotor 10 housing space in the gyro case 20, the gyro rotor 10 is assembled in a vacuum atmosphere or evacuated after being assembled. In order to maintain the vacuum state for a long period of time, a getter member (vacuum maintaining member) is also housed in the vacuum space.

Japanese Patent No. 3008074 (FIGS. 1, 2, 4, and 8) JP 2001-235329 A (FIGS. 1, 2, 3, and 6)

[Undisclosed prior art useful for explaining solution issues]
[Prior Patent Application 1] Japanese Patent Application No. 2003-050223 [Prior Patent Application 2] Japanese Patent Application No. 2002-362031 [Prior Patent Application 3] Japanese Patent Application No. 2003-099695 By the way, when the miniaturization of the electrostatic levitation type gyro device advances. Specifically, when the diameter of the gyro rotor 10 is reduced to about several millimeters or less, it is difficult to perform the work in each stage regardless of whether the assembly is performed in a vacuum atmosphere or vacuuming after the assembly. Become. For this reason, it is difficult to ensure a vacuum state, and it may lead to an undesired cost increase due to an increase in man-hours and a decrease in yield. In addition, since the burden on the getter increases due to the dimensional effect associated with downsizing, it is difficult to maintain a vacuum state. Moreover, since the cost of the through hole of the glass gyro case 20 is increased, the cost is increased. Therefore, in order to achieve both a request for downsizing and a request for cost reduction, the same applicant has devised a specific embodiment in consideration of the mounting state with respect to securing and maintaining a vacuum state. The main point is that by introducing a vacuum package and expanding the vacuum space more than the gyro mechanism part and taking in the vacuum maintenance member and electronic circuit in it, miniaturization can be promoted without increasing the difficulty of vacuum maintenance etc. It is possible to realize a small electrostatic levitation gyro device at a low cost (refer to the prior patent application 1).

Further, regarding the signal detection circuit for detecting the relative displacement between the gyro rotor and the gyro case, an improvement plan has been created by the same applicant (refer to the prior patent application 2), and the main points thereof will be described.
In the conventional signal detection circuit described above, since the displacement detection application signals f1 to f12 are superimposed on the control voltages V1, V12, etc., the sum of both voltages does not exceed the power supply voltage Vcc of the control output circuit 54. Since this is not possible, the power supply voltage Vcc is assigned to the amplitude voltage Vf of the displacement detection application signal f1 and the maximum voltage of the control voltage V1 (see FIG. 18D). However, when the mechanism of the electrostatic levitation gyro is reduced in size, specifically, for example, when the diameter of the gyro rotor 10 which is conventionally about 5 mm is reduced to about 1 mm, the capacity of the plurality of electrodes 31 to 48 is increased. Get smaller. In particular, the input current Ip to be detected by the current detection circuit 51, which is the source of the displacement detection detection signal Vp, is drastically reduced. For this reason, in order to obtain a displacement detection detection signal Vp of an appropriate level necessary for accurately obtaining the displacement ΔX and the like, it is necessary to increase the amplitude voltage Vf of the displacement detection application signal f1.

  However, increasing the amplitude voltage Vf under the predetermined power supply voltage Vcc is accompanied by a decrease in the maximum voltage of the control voltage V1, so that the balance of allocation to both is undesirably broken (see FIG. 18 (e)). ). The same applies to other displacement detection application signals. Therefore, it is important to improve the signal detection circuit so that the amplitude voltage of the displacement detection application signal can be increased under the same power supply voltage without sacrificing the control voltage. An improved solution to meet such a demand is achieved by reversing the flow of the displacement detection signal from the conventional one so that the superposition of the control voltage and the displacement detection signal is performed by the voltage significant signal and the current significant signal. As a result, it is possible to increase the amplitude voltage of the displacement detection applied signal without sacrificing the control voltage. As a result, even if the electrode capacitance is decreased, an appropriate level of displacement detection detection signal can be easily obtained. As a result, an electrostatic levitation gyro signal detection circuit suitable for miniaturization can be realized.

  Since many of the technical matters described in these unpublished prior patent applications 1 and 2 are the premise of the inventive idea, they will be reprinted here before presenting the problems of the present invention. First, a specific configuration of the electrostatic levitation gyro apparatus will be described with reference to the drawings. 1A and 1B show the structure of the device packaging, in which FIG. 1A is a front view of the device, FIG. 1B is a plan view of the device with the lid removed, and FIG. 2A is an overall circuit diagram including a signal detection circuit, FIG. 2B is a displacement detection application signal generation circuit, and FIG. 2C is a current detection circuit. 3A shows a signal input circuit for the constraint control system, and FIG. 3B shows a signal input circuit for the rotor drive system. In the drawings, the same reference numerals are given to the same components as those in the prior art, and the gyro mechanism described in the column of the premise technique is also used as it is in the following prior art examples. Therefore, it demonstrates centering on difference with the past. Again, for the sake of clear contrast, the electronic circuit unit is a specific example of an annular rotor type gyro, and the electronic circuit unit will be described after describing the gyro mechanism unit.

  This gyro device 70 (see FIG. 1) is provided with a sealable device package (vacuum container) consisting of a cap 71 (lid) and a box 72 (box, can). Are a gyro mechanism part composed of the gyro rotor 10 and the gyro case 20 described above, a base 73 (mounting substrate) made of an insulating substrate such as glass, a getter 75 (vacuum maintaining member), and ICs 77 and 78 (integrated circuits). And are stored.

  The cap 71 and the box 72 are made of a member that is excellent in air tightness and easy to process, for example, metal. When the box 71 is covered with the cap 71 and exhausted from the vacuum suction port 76 formed through the front wall of the box 72, When the space is evacuated and the vacuum suction port 76 is further plugged, it is hermetically sealed and a vacuum state is established. A large number of pins 74 (external connection terminals) are planted on the bottom surface of the box 72. The pin 74 is used to establish electrical continuity inside and outside the device package and to support the package when mounted on a printed circuit board. For example, the pin 74 is made of a good conductor similar to a pin of a multi-pin IC PGA (Pin Grid Array) package. Thus, in this example, they are generally arranged in a quadrilateral shape, and all of them penetrate the bottom surface of the box 72. The through hole of the pin 74 is filled with, for example, molten glass for fixing, airtightness and insulation.

  The base 73 is a flat plate that is slightly smaller than the inner bottom of the box 72, is supported by a number of pins 74 in the box 72, and is slightly separated from the bottom surface of the box 72. Although illustration is omitted, a wiring pattern is formed on the upper surface of the base 73, and an appropriate wiring is connected to each pin 74. This connection is made of metal or the like and serves as a connection between the pin 74 and the base 73. The gyro case 20 and the ICs 77 and 78 are mounted on the upper surface of the base 73. The wiring pattern can be connected to the gyro case 20 by wire bonding. In this example, the ICs 77 and 78 are mounted as bare chips. Therefore, the COG (Chip On Glass) method is used in which gold bumps, solder balls, and the like are connected together.

The gyro mechanism section may be a vacuum-sealed storage space of the gyro rotor 10 of the gyro case 20 as described above, but in this case, since the gyro case 20 is entirely housed in a vacuum device package, there is no need for sealing. There is no need to incorporate a getter member in the gyro case 20.
The getter 75 maintains a vacuum state by adsorbing a gas such as oxygen or nitrogen remaining in or entering the vacuum space in the apparatus package. The getter 75 is a conventional getter member built in the gyro case 20. In comparison, the material is the same, but the size is considerably larger. The getter 75 may be mounted on the base 73, but in this example, a non-evaporable getter that is activated by energization heating is adopted, so the two pins 74 are connected via a wire. It is supported.

  The ICs 77 and 78 are obtained by integrating the control output circuit 54, the current detection circuit 51, the supply circuits for the application signals f1 to f12, and the like if the electronic circuit has the configuration shown in FIG. However, here, since the electronic circuit is improved centering on the signal detection circuit, the integrated parts in the ICs 77 and 78 are also partially different accordingly. A specific integrated portion will be described after detailed differences in electronic circuits, but the ICs 77 and 78 are mounted on the base 73 as bare chips. The number of chips may be two as shown, may be combined into one, or may be three or more.

  Next, the electronic circuit unit will be described. This electronic circuit is different from that of the above-described conventional example (see FIG. 2A), in which an applied signal generating circuit 61 (applied signal supply circuit) is replaced with the displacement detecting electrodes 38 and 48 in place of the current detecting circuit 51. , The point that the displacement detection application signals f1 to f12 are not superimposed on the output of the control output circuit 54, and instead the control output circuit 54 is provided with a current detection circuit 64, and the control circuit 52 , 53 are digitized to become a rotor control circuit 62 and a control arithmetic circuit 63.

  The applied signal generation circuit 61 may generate a sine wave signal as the displacement detection application signal V0 as long as it satisfies the requirement that the frequency is high enough not to affect the motion of the gyro rotor 10, and the amplitude of the displacement detection application signal V0. May be arbitrarily set within the range allowed by the power supply voltage, but here (see FIG. 2B), in order to generate a triangular wave voltage signal as the displacement detection application signal V0, a pair of constant current circuits are reversed. Current sending and current suction are alternately repeated by a switch or the like provided in the direction and switched by the clock CLKa.

  The displacement detection applied signal V0 generated by such a constant current circuit pair and the switch circuit is directly connected to the displacement detection electrode via an appropriate coupling capacitor 61a as shown in the drawing or not. 38, 48. With this configuration, the displacement detection application current i0 supplied from the application signal generation circuit 61 to the parallel connection point of the displacement detection electrodes 38 and 48 has a rectangular wave shape in which the direction of the constant current is inverted in synchronization with the clock CLKa. The displacement detection application signal V0 is a triangular wave voltage signal. The frequency of the clock CLKa is set to 1 MHz or more, for example. This is much higher than several tens of kHz, which is the effective frequency of the control voltage, and the above requirement is satisfied.

  The current detection circuit 64 (see FIG. 2A) is a set of twelve or twelve sets for sending control voltages V1, V12, etc. for posture control from the control arithmetic circuit 63 to the electrostatic support electrodes 31-36, 41-46. Each of the control output circuits 54 is also attached to each of the control output circuits 54 for sending a control voltage for rotational driving from the rotor control circuit 62 to the rotor driving electrode 37. Each current detection circuit 64 (see FIG. 2C) performs a signal amplification, noise removal, and the like on a pair of current mirrors 64a and 64b, a differential output line 64c connecting the output lines. It comprises an amplifier 64d that outputs a detection current i1 for displacement detection and the like.

  The current mirror 64a is inserted and connected to the high potential side (+) of the power supply line of the control output circuit 54 (particularly the output stage circuit) of the attachment destination on the input side, and the current mirror 64b is attached to the attachment side of the current mirror 64b. Of the power supply lines of the control output circuit 54 (particularly, the output stage circuit), the power supply line is inserted and connected to the low potential side (−), and both output sides are connected to the differential output line 64c. As a result, each of the current detection circuits 64 detects the output current of the corresponding control output circuit 54 and generates displacement detection detection currents i1 to i12 and r1 to r6 that are the same as or correspond to them. It has become.

  The calculation contents of the control arithmetic circuit 63 are basically the same as the conventional example, but the circuit configuration (see FIG. 3A) is digitized by the adoption of the DSP 66 (digital signal processor). A / D conversion circuit 65 is provided. In this example, six A / D conversion circuits 65 are provided, and all of them are sampled and sampled at the timing of the clock CLKb and quantized with, for example, 12 bits. The clock CLKb is obtained by shifting the phase of the clock CLKa described above by 90 °, for example, and is synchronized with the clock CLKa. If the transient state at the time of switching is removed, the phase difference may be other than 90 °, and the frequency may be multiplied or decreased.

  The six A / D conversion circuits 65 take the difference between the displacement detection detection current i1 to the electrostatic support electrode 31 and the displacement detection detection current i12 to the electrostatic support electrode 41 to obtain the X-direction displacement ΔX. The component of the Y-direction displacement ΔY is obtained by taking the difference between the signal obtained by extracting the above-mentioned component, the detection current i2 for detecting displacement to the electrostatic support electrode 32, and the detection current i11 for detecting displacement to the electrostatic support electrode 42. A signal obtained by taking the difference between the extracted signal and the detection current i3 for displacement detection to the electrostatic support electrode 33 and the detection current i10 for displacement detection to the electrostatic support electrode 43 and extracting the component of the displacement ΔZ + Δφ in the Z + φ direction And a signal obtained by extracting the component of the displacement ΔZ + Δθ in the Z + θ direction by taking the difference between the detection current i4 for displacement detection to the electrostatic support electrode 34 and the detection current i9 for displacement detection to the electrostatic support electrode 44, Detection current i5 for detecting displacement to the electrode 35 for electric support and electrostatic A signal obtained by extracting the component of the displacement ΔZ−Δφ in the Z-φ direction by taking the difference from the detection current i8 for detecting the displacement to the holding electrode 45 and the detection current i6 for detecting the displacement to the electrostatic support electrode 36 and static It is assigned to a signal obtained by extracting the component of the displacement ΔZ-Δθ in the Z-θ direction by taking the difference from the detection current i7 for detecting the displacement to the electrode 46 for electric support.

  The calculation content of the rotor control circuit 62 is basically the same as that of the conventional example, but the circuit configuration (see FIG. 3B) is also digitized by the adoption of the DSP 67, so that quantization means is provided in the previous stage. It has been. The quantization means may be the same as that of the A / D conversion circuit 65. However, in order to perform the rotor rotation control, it is sufficient to grasp one or more phases of the displacement detection detection currents r1 to r6. A comparator COMP simpler than the / D conversion circuit 65 is provided for each of the detection currents r1 to r6 for displacement detection. Each binarized displacement detection signal is input to the DSP 67 at any time by the sampling program processing of the DSP 67 and is sampled, and then a three-phase pulse signal or the like based on the rotation state of the gyro rotor 10 around the Z-axis. The rotation driving control voltage is generated by a known calculation.

  Among such electronic circuits, the control output circuit 54, the current detection circuit 64, the applied signal generation circuit 61, and the like are integrated in the ICs 77 and 78. The DSPs 66 and 67 may be dedicated products, but general-purpose commercially available products are sufficient, and such DSPs 66 and 67 are not integrated in the ICs 77 and 78.

  The use mode and operation of the electrostatic levitation gyro apparatus having such a configuration will be described with reference to the drawings. FIG. 1D is a perspective view showing a device mounting state. 4A is a detailed view of a control voltage application portion, and FIGS. 4B to 4F are signal waveform examples. Also here, the mounting mode of the mechanism part will be described first, and then the operation of the electronic circuit will be described.

  In order to mount the gyro device 70 on the printed circuit board 80 (see FIG. 1D), prior to that, a through hole corresponding to the pin 74 and a wiring pattern for electrical connection are formed on the printed circuit board 80. ICs such as DSPs 66 and 67 and other electronic components are mounted on the printed circuit board 80 using a general IC mounting technique. A regulator IC 81, a smoothing capacitor 82, and the like constituting the power supply circuit are also mounted. Then, a pin 74 is inserted into the through hole of the printed board 80 and connected by soldering or the like.

  Then, the gyro device 70 is fixed to the printed circuit board 80, and the gyro case 20 is fixed to the printed circuit board 80, and the electrical connection between the electrodes 31 to 48 of the gyro case 20 and the electronic circuit is established. . Specifically, the ICs 77 and 78 which are built-in parts of the electronic circuit are connected to the gyro case 20 by the wiring pattern of the base 73 when the assembly of the gyro device 70 is completed. Are connected via the wiring pattern of the printed circuit board 80 and the pins 74. Thus, when the electrostatic levitation gyro device is mounted on the printed circuit board 80 and incorporated in an automobile or the like, the gyro mechanism and the electronic circuit can be operated.

  As is apparent from the above description, the gyro device 70 can be easily mounted in substantially the same manner as a familiar IC such as a PGA type IC. Furthermore, regarding the vacuuming of the gyro device 70, since it is a device package that is larger and more durable than the gyro case 20 and is easy to handle, the work becomes easier and the existing equipment and jigs can be used continuously. Regarding the maintenance of the vacuum state, the getter 75 can be made sufficiently large. For example, the getter 75 can be made so large that it does not fit in the gyro case 20, so that the vacuum state is maintained for a long period of time. The vacuum space was conventionally sealed with thin glass or the like, but since it is sealed with a package 71 + 72 made of a metal that is thicker and more deformable, the hermetic performance is improved. A vacuum state is maintained over a long period of time. Moreover, the gyro device 70 includes not only the gyro case 20 but also ICs 77 and 78, which are part of the electronic circuit, in a bare chip state, thereby enabling compact mounting of the electronic circuit unit. It is further advanced. The ICs 77 and 78 are mounted on a bare chip. However, the internal space of the gyro device 70 surrounding the ICs 77 and 78 is in a vacuum state, so that it does not deteriorate due to oxidation or the like.

  Next, the operation of the electronic circuit will be described (see FIG. 4A). For the sake of clarity and comparison with the conventional example, the electrode pairs 31 and 41 of the six pairs of electrostatic rotor support electrodes of the annular rotor type will be described. The application state of the control voltage will be described in detail. The control voltage V1 is also divided into a pair of a positive voltage V1b and a negative voltage V1a, the positive voltage V1b is applied to the electrostatic support electrode 31b, and the negative voltage V1a is applied to the adjacent electrostatic support electrode 31a. . The control voltage V12 is also divided into a pair of a positive voltage V12b and a negative voltage V12a. The positive voltage V12b is applied to the electrostatic support electrode 41b, and the negative voltage V12a is applied to the adjacent electrostatic support electrode 41a. The

  And (see FIG. 4 (b)), a constant offset voltage applied to the electrostatic support electrodes 31, 41 when the gyro rotor 10 is stationary at the neutral position apart from the rotation around the Z axis is Vof, If the X-axis control voltage component calculated and changed for attitude control is Vx, the main component output from the control output circuit 54 of the positive voltage V1b is + Vof + Vx, and the main component of the negative voltage V1a is −Vof−Vx. The main component of the positive voltage V12b is set to + Vof−Vx, and the main component of the negative voltage V12a is set to −Vof + Vx. The steps so far are basically the same as in the conventional example, but the displacement detection signal is superimposed differently from the conventional example, so that the displacement detection application signal V0 is directly superimposed on these control voltages V1, V12, etc. There is nothing wrong. However, it is affected by the transmission of the displacement detection application signal V0.

  That is, (see FIG. 4C), the applied signal generation circuit 61 generates a displacement detection application signal V0 whose voltage waveform changes in a triangular wave shape, and this generates the displacement detection electrodes 38 and 48, the gyro rotor 10, and the electrostatic The voltage is superimposed on the control voltages V1 and V12 through the support electrodes 31 and 41 in order. The amplitude of the applied voltage signal V0 for displacement detection can exceed the power supply voltage Vcc of the control output circuit 54 if a booster circuit or the like is added to the applied signal generation circuit 61. It is considerably larger than f12. On the other hand (see FIG. 4B), since the voltage component superimposed on the control voltages V1 and V12 is extremely small, the waveform of the positive voltage V1b does not greatly deviate from the waveform of the main component + Vof + Vx, and the negative voltage V1a is Along the principal component −Vof−Vx, the positive voltage V12b is along the principal component + Vof−Vx, and the negative voltage V12a is along the principal component −Vof + Vx.

  On the other hand, the displacement detection applied current i0 (see FIG. 4 (d)) as well as the displacement detection applied voltage signal V0 are controlled through the displacement detection electrodes 38, 48, the gyro rotor 10, the electrostatic support electrodes 31, 41, etc. in order. At this time, the displacement detection applied current i0 is divided based on the capacitances of the plurality of electrodes 31 to 48, and at the transmission destination, the current detection circuit 64 at the corresponding location is used for displacement detection. Detected as detected current signals i1 to i12. These current signals (see the displacement detection detection current i1 in FIG. 4 (e)) show a clear current value corresponding to the division, and become a rectangular wave having a frequency corresponding to the clock CLKa.

  And (see FIG. 4 (f) and FIG. 3 (a)), the current signal (i1-i12) reflecting the X-direction displacement ΔX at the timing of the clock CLKb that is synchronized with the clock CLKa but out of phase. A similar signal is quantized by the A / D conversion circuit 65, and a known calculation for posture control is performed by the DSP 66 that has taken them in. Also, the angular velocity and acceleration with respect to the inertial space are calculated. Thus, also in this case, posture control, acceleration detection, and the like are appropriately performed. Further, the displacement detection detection currents r1 to r6 are binarized and taken into the DSP 67, and a known calculation for rotational driving is performed by the D67SP that has taken them. The upper limit of the fundamental frequency of the rotational drive control voltage is about several hundreds Hz. However, since the fundamental frequencies of the detection currents r1 to r6 for displacement detection are high as described above, both are easily and accurately discriminated. Thus, the rotor rotational drive is also appropriately performed.

  As is clear from the above description, in the signal detection circuit of the electrostatic levitation type gyro, the applied voltage signal V0 for displacement detection can be expanded as required, and the control voltage V1, Since V12 and the like can be expanded to near the power supply voltage Vcc of the control output circuit 54, a sufficient signal level can be secured even if the capacity of the plurality of electrodes 31 to 48 is reduced due to the downsizing of the gyro mechanism. In addition to properly detecting displacement, it also contributes to improved attitude control performance.

In addition to the technical matters described in these unpublished prior patent applications 1 and 2, the technical matters described in the unpublished prior patent application 3 are also the premise of the present invention, and many Since this part has been taken over by the present invention, the outline will be re-posted.
As described above, even if the gyro mechanism or electronic circuit is incorporated into the vacuum package in order to reduce the size in consideration of the mounting situation, or even if the electrode capacity decreases due to the downsizing of the gyro mechanism, the detection signal for detecting the displacement at an appropriate level Thus, the flow of the displacement detection signal is reversed from that of the prior art to reduce the size of the electrostatic levitation gyro device, and the application range of the electrostatic levitation gyro device is expanded. However, just because miniaturization has become possible, not everything is replaced with a smaller one.

In the case of an electrostatic levitation type gyro apparatus that utilizes the inertia by rotating the gyro rotor, the detection accuracy cannot be avoided depending on the size of the gyro rotor. Various voltages are adopted for the power supply voltage Vcc, the control voltage V1, and the like according to the size. For example, when the rotor diameter is 1 to 2 mm, a voltage of about 3 V or 5 V is sufficient, but when the rotor diameter exceeds 5 mm, a voltage of 12 V or 15 V is often used.
However, if the voltage of the electronic circuit is high, usable electronic parts are limited or expensive. In particular, when a semiconductor component that operates at a high speed such as 1 MHz and requires a wide dynamic range such as a current mirror of the current detection circuit 64 is required to have a high breakdown voltage performance of about 15 V or more, it can be realized at an appropriate price. It becomes difficult.

In that case, the conventional technique of superimposing the displacement detection application signal directly on the control voltage is continuously used.
However, the method of detecting the signal component related to the displacement detection application signal in the output stage circuit of the control voltage by reversing the flow of the displacement detection signal from that of the prior art requires almost no sacrifice of the control voltage. In addition, there are many advantages over the prior art in that the level of the displacement detection application signal can be set almost freely without being restricted by the control voltage.

  Accordingly, a signal detection circuit having a new configuration different from any of the above has been devised on the premise of adopting a technique of applying a displacement detection signal to the displacement detection electrode and performing detection closer to the control circuit than the control electrode. The main point is that when a displacement detection signal is applied to the displacement detection electrode and the detection is performed closer to the control circuit than the control electrode, a reverse-phase control voltage is applied to the adjacent control electrode and an in-phase displacement detection is performed. An electrostatic levitation type gyro apparatus in which the flow of the displacement detection signal is reversed from that of the prior art by performing signal detection by extracting the in-phase component based on the transmission of the applied signal. The thing was able to be realized. In addition, further contrivance has been added so that the influence of the power supply voltage and the control voltage does not reach the detection signal generation circuit as much as possible. For example, when detecting the flow of the displacement detection signal by reversing the conventional flow, the voltage such as the control voltage The common-mode detection circuit can be implemented with a passive element so that the restriction by level becomes loose.

A specific configuration of the signal detection circuit of the electrostatic levitation gyro apparatus will be described with reference to the drawings. 5A is an overall circuit diagram including a signal detection circuit, FIG. 5B is a displacement detection application signal generation circuit, FIG. 5C is a detection signal generation circuit, and FIG. 6A is a control. It is a detailed view of a voltage application part and a detection signal generation circuit.
When the difference is described, the signal detection circuit shown in FIGS. 5 and 6 is different from that shown in FIGS. 2 to 4 in that the applied signal generation circuit 61 for generating a rectangular wave current is used for generating a rectangular wave voltage. And the common-mode detection circuit 91 instead of the current detection circuit 64 has become the main part of the detection signal generation circuit. Others are basically the same.

  The applied signal generation circuit 90 (see FIG. 5B), like the applied signal generation circuit 61, is a sinusoidal wave as the displacement detection application signal V0 if the frequency is high enough not to affect the motion of the gyro rotor 10. In this case, in order to generate a rectangular wave signal suitable for digitization, the clock CLKa is amplified by an amplifier to generate the displacement detection applied voltage signal V0. Also in this case, since the displacement detection applied voltage signal V0 is applied to the displacement detection electrodes 38 and 48, the amplitude of the displacement detection applied signal V0 can be arbitrarily set within the range allowed by the power supply voltage.

The common-mode detection circuit 91 is provided for each control output circuit 54 (see FIG. 5A), and each (see FIG. 5C) includes one midpoint voltage detection circuit 92 and two current limiting circuits 93. Therefore, it is attached to the output side of the control output circuit 54.
The control output circuit 54 that applies the control voltage V1 to the electrostatic support electrode 31 will be described as a specific example (see FIG. 5C). As described above, the electrostatic support electrodes 31 are adjacent to each other. The control electrode V1 is composed of a support electrode 31a and an electrostatic support electrode 31b, and the control voltage V1 is divided into a pair of a negative voltage V1a and a positive voltage V1b that are in opposite phase to each other, and the positive voltage V1b is an electrostatic support electrode. The negative voltage V1a is applied to the adjacent electrostatic support electrode 31a.

  On the premise of this, the common-mode detection circuit 91 detects the signal component m1 related to the displacement detection applied voltage signal V0 by extracting the common-phase component from the reverse-phase outputs V1a and V1b of the control output circuit 54 to which it is attached. Then, this is sent as a displacement detection detection signal m1 to the control arithmetic circuit 63 instead of the displacement detection detection current i1, and therefore, the midpoint voltage detection circuit 92 is connected to the negative voltage V1a line. The current limiting circuit 93 is connected to both the positive voltage V1b line as a bridge, and one current limiting circuit 93 is interposed between the midpoint voltage detection circuit 92 and the control output circuit 54, and is connected to the negative voltage V1a line. The other is connected to the positive voltage V1b line.

  As a specific circuit configuration example (see FIG. 6A), the midpoint voltage detection circuit 92 is composed of a circuit in which two capacitors C (capacitance elements) having the same capacitance are connected in series. One end is connected to the positive voltage V1b line and the other end is connected to the negative voltage V1a line. The detection signal m1 is taken out from the connection point between the capacitors C, and this signal line extends to the control arithmetic circuit 63. Each of the current limiting circuits 93 includes a resistor R, and is connected between the output terminal of the control output circuit 54 and the connection point of the capacitor C with respect to each of the negative voltage V1a and positive voltage V1b lines. . Although a detailed description that will be repeated is omitted, the electrostatic support electrode 41 that is opposed to the electrostatic support electrode 31 is similarly provided with a midpoint voltage detection circuit 92 and a current limiting circuit 93 to detect displacement. The detection signal m12 is generated and sent to the control arithmetic circuit 63. Although the detailed view is omitted, the same applies to the other control electrodes 32 to 36 and 42 to 46.

The use mode and operation of the signal detection circuit of such an electrostatic levitation gyro apparatus will be described with reference to the drawings. 6B to 6E are examples of signal waveforms. Here again, the electrode 31 among the six pairs of electrostatic rotor supporting electrodes of the annular rotor type will be described in detail.
Then (see FIG. 6B), the offset voltage Vof applied to the electrostatic support electrode 31 and the X-axis control voltage component Vx calculated and changed for the attitude control are the same as those in the aforementioned prior patent applications 1 and 2. Since it is the same as the description example, the main component output from the control output circuit 54 of the positive voltage V1b is set to + Vof + Vx, and the main component of the negative voltage V1a is set to -Vof-Vx. The main component of the positive voltage V12b is + Vof−Vx, and the main component of the negative voltage V12a is −Vof + Vx.
The negative phase control voltage V1, that is, the negative voltage V1a and the positive voltage V1b are also sent from the control output circuit 54 to the electrostatic support electrode 31, and the displacement detection application signal V0 is directly superimposed thereon. The displacement detection application signal V0 is transmitted from the electrostatic support electrode 31 to the control output circuit 54 in the reverse direction.

  That is, (see FIG. 6C), the applied signal generating circuit 90 generates a displacement detection application signal V0 whose voltage waveform is a rectangular wave with a duty ratio of 50%, and this is applied to the displacement detection electrode 38, the gyro rotor 10, and the like. The voltage is superposed on the control voltage V1 through the electrostatic support electrodes 31 in order. The amplitude of the applied voltage signal V0 for displacement detection can exceed the power supply voltage Vcc of the control output circuit 54 as in the case of the applied signal generating circuit 61 if a booster circuit or the like is added to the applied signal generating circuit 90. It is considerably larger than the conventional displacement detection application signal f1 and the like. On the other hand (see FIG. 6B), since the voltage component superimposed on the control voltage V1 is extremely small, the waveform of the positive voltage V1b does not greatly deviate from the waveform of the main component + Vof + Vx, and the negative voltage V1a is the main component. Along the −Vof−Vx, each draws a waveform almost the same as the main component.

  Since the applied voltage signal V0 for displacement detection is transmitted in phase to the adjacent electrostatic support electrodes 31a and 31b, it is transmitted to the output line of the control output circuit 54 via the electrostatic support electrode 31. In this case, the control voltages V1a and V1b having opposite phases are superimposed on the same phase (see the solid line graph in FIG. 6B). When this voltage component is m1, the positive voltage V1b is + Vof + Vx + m1, and the negative voltage V1a is -Vof-Vx + m1. Then, the midpoint voltage detection circuit 92 detects a voltage just between the two. This detection signal m1 (see FIG. 6D) contains only the in-phase component related to the displacement detection applied voltage signal V0 because the anti-phase component of the control voltage V1 cancels out and does not remain. If the disturbance at the edge or the like is ignored, the waveform becomes a rectangular wave having a frequency corresponding to the clock CLKa, and the amplitude thereof includes the electrostatic capacitance of the electrostatic support electrode 31 and the gyro rotor 10 and the relative displacement between the two. ΔX is accurately reflected.

  Then (see FIGS. 6 (e) and 6 (a)), the detection signal m1 reflecting the X-direction displacement ΔX at the timing of the clock CLKb synchronized with the clock CLKa but shifted in phase, and the electrostatic support electrode The detection signal m12 obtained in the same manner from the 41 side is appropriately amplified and then quantized by the A / D conversion circuit 65, and the other electrostatic support electrodes 32-36 and electrostatic support electrodes 42-46. Similarly, a displacement detection detection signal is obtained by the in-phase detection circuit 91, quantized by the A / D conversion circuit 65, and a known calculation for posture control is performed by the DSP 66 that has taken them in. Also, the angular velocity and acceleration with respect to the inertial space are calculated. Thus, also in this case, posture control, acceleration detection, and the like are appropriately performed. Further, although the signs of the displacement detection detection signals r1 to r6 are not changed in the drawing, they are also obtained as voltage signals instead of current signals, binarized and taken into the DSP 67, and the DSP 67 that takes them in. Thus, a known calculation for rotational driving is performed.

  The capacitance of the capacitor C and the resistance value of the resistor R are the main components of the control voltage V1 in consideration of the capacitance between the electrostatic support electrode 31 and the gyro rotor 10, the output voltage of the control output circuit 54, and the like. The current of the frequency component included in Vof + Vx passes through the current limiting circuit 93 well (that is, the resistance can be ignored if viewed in a long cycle), but the current of the frequency component of the displacement detection applied voltage signal V0 passes through the current limiting circuit 93. It is selected so that it hardly passes (that is, resistance cannot be ignored when viewed in a short period). For example, the frequency of the negative phase component Vx of the control voltage V1 is at most several tens of kHz, the frequency of the displacement detection applied voltage signal V0, that is, the basic frequency of the detection signal m1 is 1 MHz, and the electrostatic support electrode 31 is static. When the capacitance is about 0.1 pF, the capacitor C and the resistor R may be 20 pF and 250 kΩ, respectively.

Thus, the control voltage V1 is appropriately applied to the electrostatic support electrode 31 regardless of the presence or absence of the in-phase detection circuit 91. In addition, the signal component related to the applied voltage signal V0 for displacement detection is generally transmitted to the midpoint voltage detection circuit 92 by the current limiting circuit 93 without being absorbed by the control output circuit 54 having a small output impedance. Therefore, the detection signal m1 is reliably detected with a small amplitude. The same applies to the other detection signals for displacement detection.
Thus, the rotor attitude control is appropriately performed. Similarly, rotor rotation driving with a fundamental frequency of at most several hundred Hz is also appropriately performed.

  As is clear from the above description, in the signal detection circuit of the electrostatic levitation type gyro, the applied voltage signal V0 for displacement detection can be expanded as required, and the control voltage V1, Since V12 and the like can be expanded to near the power supply voltage Vcc of the control output circuit 54, a sufficient signal level can be secured even if the capacity of the plurality of electrodes 31 to 48 is reduced due to the downsizing of the gyro mechanism. In addition to properly detecting displacement, it also contributes to improved attitude control performance. Furthermore, even if the capacitor C and the resistor R as described above correspond to a frequency of several MHz or more, those having a withstand voltage performance of several tens of V or more can be easily obtained. The present invention is applicable not only to a small gyro device having a power supply voltage Vcc, control voltage V1, etc. of several volts, but also to an electrostatic levitation type gyro device having a power supply voltage Vcc, control voltage V1, etc. exceeding tens of volts. be able to.

[Technical problem to be solved by the invention]
As described above, regarding the electrostatic levitation type gyro device, diversification of mechanisms (refer to Patent Documents 1 and 2), improvement of mounting mode (refer to Prior Patent Application 1), improvement of signal detection circuit (refer to Prior Patent Applications 2 and 3) The control output circuit 54 uses an analog circuit as it is in the past. In the typical configuration, for example, in the typical configuration that outputs the control voltage V1 (that is, positive and negative voltages V1a and V1b) applied to the electrostatic support electrode 31 (that is, the adjacent electrodes 31a and 31b) (FIG. 7A). )), A non-inverting amplifier (Amp, signal amplifier) that operates with a positive power supply (+ Vcc) to generate a positive voltage V1b, a level shifter (level conversion circuit) that shifts the signal level from positive to negative, and a negative power supply (− An inverting amplifier (Amp, signal amplifier) that operates at Vcc) and generates the negative voltage V1a is required for each control output circuit 54. In addition, as described above, a circuit for setting the offset voltage Vof is attached to each amplifier.

  The electrostatic attractive force F (electrostatic support force) acting on the electrostatic support electrode 31 of the capacitor structure is non-linearly related to the control voltage V1 applied to the electrostatic support electrode 31 (secondary expression, (Refer to FIG. 7B), in order to stabilize the control, the X axis is set within a predetermined range centered on the offset voltage Vof, that is, a range that can be regarded as approximately satisfying the linear relationship. Since the control voltage component Vx is limited, the entire range of the power supply voltage Vcc cannot be effectively used for the control voltage. The other control voltages V12 and the like are the same as those generated by the analog control output circuit 54.

  As an improvement plan for this, it is conceivable to adopt a pulse width modulation method. For example (see FIG. 7 (c)), the switch circuit SWb (see FIG. 7C) generates a signal generated by the control arithmetic circuit 63 by pulse width modulation by a pulse width modulation circuit (PWM) to generate an on / off signal (binary signal). Another switching circuit that selects the positive power supply voltage + Vcc when turned on in the switching circuit) and selects the ground voltage (0 V, reference voltage) when turned off to generate the positive voltage V1b and switches the same on / off signal as a control signal When the SWa (switching circuit) is turned on, the negative power supply voltage -Vcc is selected, and when it is turned off, the ground voltage (0 V, reference voltage) is selected to generate the negative voltage V1a.

  Thus, the electrostatic attractive force F acting on the electrostatic support electrode 31 and the pulse width modulation rate (%) of the control voltage V1 applied to the electrostatic support electrode 31 are (0 to 100%) over the entire range. Since it becomes a linear relationship (proportional expression, linear function) (see FIG. 7 (d)), it is not necessary to limit the variable range (corresponding to Vx) of the control voltage component, so the entire range of the power supply voltage Vcc is controlled by the control voltage. It can be used effectively for V1. For other control voltages V12 and the like, the same effect can be obtained by converting the control output circuit to PWM (pulse width modulation). That is, the control capability can be improved by using the power supply voltage Vcc without waste. Further, it is possible to obtain the advantages of simplification of the output stage circuit and reduction of energy waste, which are general effects of PWM.

  However, there is a side effect of inducing undesired switching noise in such control voltage PWM. More specifically (see FIGS. 7E to 7G), the displacement detection applied current i0 (see FIG. 7E) generated by switching from the applied signal generating circuit 61 or the applied signal generating circuit 90. The displacement detection application signal V0 (see FIG. 7 (e)) generated by amplifying the clock in step 1 passes through the displacement detection electrode 38, the gyro rotor 10, and the electrostatic support electrode 31, and then is subjected to pulse width modulation. Since it is superimposed on the generated control voltage V1 (see FIG. 7 (f)), current detection and midpoint voltage detection are performed there, and a displacement detection detection current i1 and a displacement detection detection signal m1 are generated. A large switching noise is superimposed on these displacement detection detection signals i1 and m1.

For this reason, if the sampling timing (signal input timing) of the detection signals i1 and m1 is unlucky and coincides with the switching noise, the detection accuracy is lowered and the control performance is lowered.
Therefore, in order to maintain the advantage that displacement can be detected almost without sacrificing the control voltage, and the level of the applied signal for displacement detection can be set almost freely without being restricted by the control voltage, displacement detection is performed on the displacement detection electrode. The control voltage is converted to PWM to obtain the advantage of improving the control capability by using the power supply voltage Vcc without waste, on the premise of adopting a method for detecting a signal closer to the control circuit than the control electrode. In addition, it becomes a technical problem to devise the configuration of the signal detection circuit and the control circuit so that the adverse effect due to the switching noise induced by the detection signal is eliminated.

  The electrostatic levitation type gyro apparatus of the present invention (Solution 1) was devised to solve such a problem, and a gyro case incorporating a gyro rotor so as to be capable of electrostatic levitation and rotation, and the gyro case A control circuit for generating and applying control voltages for attitude control and rotation drive of the gyro rotor to the electrostatic support electrode and the rotation drive electrode among the plurality of electrodes formed on the substrate, and the gyro rotor, An applied signal supply circuit for applying a displacement detection application signal for detecting a relative displacement with the gyro case to a part of the plurality of electrodes, and a displacement detection electrode to which the control voltage is not applied among the plurality of electrodes. A detection signal generation circuit that detects a signal component related to the displacement detection application signal through a position, generates a displacement detection detection signal, and sends the detection signal to the control circuit In the electrostatic levitation gyro apparatus, the application signal supply circuit applies the displacement detection application signal to the displacement detection electrode, and the detection signal generation circuit controls the control in the control circuit. The control circuit performs pulse width modulation when generating the control voltage, and the pulse end is changed suddenly in the displacement detection application signal. It is characterized by being synchronized with a point.

  Here, the above-mentioned “sudden change point” means the timing at which the signal waveform suddenly changes. “Sudden change” includes not only a discontinuous change but also a bend change in which an angle is recognized in the waveform whether it is an acute angle or an obtuse angle. Applicable. For example, if it is a pulse signal, the pulse end, that is, the start point and end point of the pulse is a sudden change point, if it is a rectangular wave, the point at which the vertical line appears is a sudden change point, and if it is a triangular wave, there are break points that appear alternately above and below. It is a sudden change point.

  Further, the electrostatic levitation type gyro apparatus of the present invention (Solution means 2) is the electrostatic levitation type gyro apparatus of Solution means 1, wherein the detection signal generation circuit is distributed and attached to the output stage circuit. A plurality of current detection circuits are provided, and each of the current detection circuits detects a signal component related to the displacement detection application signal with respect to an output current of an output stage circuit as an attachment destination. To do.

  Furthermore, the electrostatic levitation type gyro apparatus of the present invention (Solution means 3) is the electrostatic levitation type gyro apparatus of Solution means 1, wherein the output stage circuit relates to at least one of the control voltages for posture control. Is to generate a reverse phase and apply it to the adjacent one of the plurality of electrodes, and the detection signal generation circuit has a plurality of in-phase detection circuits attached to the output side of each of the output stage circuits. The common-mode detection circuit detects the signal component related to the displacement detection application signal by extracting the common-phase component from the reverse-phase output of the output stage circuit of the attachment destination. And

  In such an electrostatic levitation gyro device of the present invention (Solution 1), the application signal supply circuit, the detection signal generation circuit, and the connection destination are switched, and the displacement detection application signal is applied to the displacement detection electrode. At the same time, detection of the signal component used for generating the displacement detection detection signal is performed in a distributed manner at the output stage circuit of the control voltage in the control circuit. In this way, by adopting a technique for applying a displacement detection signal to the displacement detection electrode and performing detection closer to the control circuit than the control electrode, displacement detection can be performed with almost no sacrificing control voltage. The level of the displacement detection application signal can be set almost freely without being restricted by the control voltage.

In addition, since the control voltage generated by the control circuit is also pulse-width modulated, the power supply voltage can be used without waste to improve the control capability, and the output stage circuit can be simplified, and the energy Waste can also be reduced.
Further, by synchronizing the pulse end with the sudden change point of the displacement detection application signal during the pulse width modulation, the pulse end of the control voltage can be regarded as overlapping or overlapping with the sudden change point of the displacement detection application signal. Therefore, the switching noise induced in the detection signal for displacement detection due to the PWM control voltage is limited to the sudden change point of the applied signal for displacement detection.

  When there is a sudden change point in the displacement detection application signal, a transitional transition state often appears in the displacement detection detection signal, but it is not preferable to use such a transition state for displacement detection. Therefore, the use of transition states is generally avoided by sampling at other stable state timings. If the use of such a transition state is avoided in the signal detection circuit, the switching noise that appears only at the sudden change point of the displacement detection applied signal is also accompanied by the displacement detection. Removed from use.

  Therefore, according to the present invention, the signal detection circuit is improved so as to increase the amplitude voltage of the displacement detection applied signal without sacrificing the control voltage, and the control circuit uses the power supply voltage without waste to enhance the control capability. It is possible to realize an electrostatic levitation type gyro apparatus which is improved and has both advantages without damaging each other.

Further, in the electrostatic levitation type gyro apparatus of the present invention (Solution means 2), when the signal detection is performed in the output stage circuit of the control voltage by reversing the flow of the displacement detection signal from the conventional one, it is installed in a distributed manner. Since the current detection circuit is also used, a detection signal for displacement detection at an appropriate level can be easily obtained even if the electrode capacitance is reduced.
Therefore, according to the present invention, the signal detection circuit is improved so as to increase the amplitude voltage of the displacement detection applied signal without sacrificing the control voltage, and the control circuit uses the power supply voltage without waste to enhance the control capability. It is an electrostatic levitation type gyro apparatus which is improved, and both improvements have the advantages without impairing each other, and an electrostatic levitation type gyro apparatus suitable for miniaturization can be realized.

  Further, in the electrostatic levitation gyro apparatus of the present invention (solution 3), when detecting the signal at the output stage circuit of the control voltage by reversing the flow of the displacement detection signal from the conventional one, the adjacent control is performed. Based on the fact that the control voltage having the opposite phase is applied to the electrodes and the application signal for detecting the in-phase displacement is transmitted, the signal detection for detecting the displacement is performed by extracting the in-phase component. The extraction of the in-phase component can be realized by using a low-voltage electronic component that has a high withstand voltage and high responsiveness, such as a passive element, and can be performed by, for example, a method of adding signals or dividing a signal. As a result of such extraction, the detection signal for displacement detection is separated from the control voltage and becomes a single signal. Therefore, high voltage resistance performance like the output stage circuit of the control circuit is no longer required for the subsequent processing. Not.

  Therefore, according to the present invention, the signal detection circuit is improved so as to increase the amplitude voltage of the displacement detection applied signal without sacrificing the control voltage, and the control circuit uses the power supply voltage without waste to enhance the control capability. An electrostatic levitation type gyro device which is improved and has both advantages without damaging each other, and can be used for a small size, but not limited thereto, and to realize a useful electrostatic levitation type gyro device. it can.

About the electrostatic levitation type gyro apparatus of the present invention as described above, specific modes for carrying out this will be described with reference to the following first to third embodiments.
The first embodiment shown in FIGS. 8 to 11 embodies the above-described solving means 1 and 3 (claims 1 and 3 as originally filed), and the second embodiment shown in FIGS. The above-described solving means 1 and 2 (claims 1 and 2 at the beginning of the application) are embodied, and the third embodiment shown in FIG. 16 is a modification thereof.

In addition, in the illustrations, reference was made in the column of the premise technology in the column of background technology, the column of conventional technology in the column of background technology, and the column of undisclosed prior art in the column of problems to be solved by the invention. Since the same reference numerals are given to the same constituent elements as the constituent elements, the gyro mechanism described in the premise technique column in the background art section is also used as it is in the following embodiments. The repeated description will be omitted, and the following description will focus on differences from known prior art and undisclosed prior art.
Also here, for the sake of clear contrast and the like, a specific example of the electronic circuit unit corresponding to the annular rotor type gyro is taken.

  A specific configuration of the electrostatic levitation gyro apparatus according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 8A is a plan view with the lid removed, and FIG. 8B is a longitudinal front view. 9A is an entire circuit diagram including a control circuit and a signal detection circuit, FIG. 9B is a displacement detection application signal generation circuit, and FIG. 9C is a detection signal generation circuit. 10A is a detailed view of a control voltage application portion, and FIG. 10B is a detailed view of a control output circuit.

This electrostatic levitation type gyro device (see FIGS. 8 to 11) is different from the examples described in the prior patent applications 1 and 3 (see FIGS. 1, 5 and 6). (FIG. 1 → FIG. 8) and improvements regarding the control circuit (FIG. 5, FIG. 6 → FIGS. 9 to 11). The gyro mechanism and the signal detection circuit are the same as described above (see FIG. 17, see FIGS. 5 and 6).
Hereinafter, the differences will be described in detail.

  First, improvements regarding the packaging method will be described. The electrostatic levitation type gyro device 97 shown in FIG. 8 is a further improvement of the one shown in FIG. 1 described above, and the base 73 has a disk shape in order to make the base 73 of the glass substrate difficult to break. ing. Accordingly, the pins 74 are also arranged in a circular shape. The package also has a structure in which a box 71 is covered with a cap 71 and a disk-shaped bottom plate 72 is covered with a circular cap-shaped cap 71.

  Further, the pin 74 is disengaged from the base 73 toward the outer peripheral side, and the joint between them is no longer a rigid joint. The electrical connection between the two is made by a bonding wire 99, and the mechanical connection for supporting the base 73 by floating from the package bottom plate 72 is made by an elastic support member 98 made of, for example, a leaf spring. Thus, the elastic support member 98 is interposed between the pin 74 and the base 73 so that the base 73 is elastically supported only by the elastic support member, thereby improving the function of absorbing the impact. As a problem when an impact is applied, in addition to damage to the base 73, if the rotor collides with the electrode or the stopper and the rotation of the rotor stops, it is necessary to repeat the flying and rotation sequence. It can be avoided.

Next, regarding differences in the control circuit, in order to perform pulse width modulation when generating the control voltages V1 to V12, the rotor control circuit 62 is partially modified to become the rotor control circuit 102, and the control arithmetic circuit 63 A part of the control arithmetic circuit 103 is modified and the control output circuit 54 is a control output circuit 104 (see FIG. 9).
The signal input and calculation contents in the rotor control circuit 102 and the control calculation circuit 103 are the same as those of the rotor control circuit 62 and the control calculation circuit 63. The rotor control circuit 102 and the control calculation circuit 103 are the same as the rotor control circuit 62 and the control calculation circuit 63. The only difference is the portion that sent the analog signal to the control output circuit 54. Specifically (see the broken line portion in FIG. 10B), a digital value obtained by a known calculation is converted into a PWM modulation rate (pulse width modulation rate) by digital calculation without converting to an analog signal. It is converted and sent to the control output circuit 104 as a digital value.

The control output circuit 104 (see FIG. 10 (b)) is composed of digital circuits, each of which includes a pulse width modulation circuit 105 to 107 that converts the PWM modulation rate into a pulse width modulation signal Spwm of a logical signal level, and a switch circuit. And an output stage circuit 108 for converting the pulse width modulation signal Spwm at the signal level into a pulse width modulation signal pair Vpwm (+ Vpwm, −Vpwm) at the voltage Vcc level.
There is no D / A conversion circuit or analog amplifier.

  The pulse width modulation circuits 105 to 107 include a latch 105 that holds the PWM modulation rate received from the control arithmetic circuit 103, an N-ary counter 106 that advances the count value at the rising or falling edge of the clock CLKa, and changes it in a sawtooth shape. A comparator 107 that receives the count value from the N-ary counter 106, receives the PWM modulation rate from the latch 105, compares the count value with the PWM modulation rate, and generates a binary pulse width modulation signal Spwm (on / off signal); Is provided. Similarly to the N-ary counter 106, the latch 105 performs a latch operation at the rise or fall of the clock CLKa so that the pulse end of the pulse width modulation signal Spwm output from the comparator 107 coincides with the rise or fall of the clock CLKa. It has become. When 100% PWM modulation is used, the control arithmetic circuit 103 performs conversion so that the maximum value of the PWM modulation rate matches N of the N-ary counter 106. The specific value of N is “2”, “64” represented by 6 bits, “256” represented by 8 bits, etc., but other values may be used. .

  The output stage circuit 108 is provided with two-input one-output switch circuits SWa and SWb (switching circuits) that switch the pulse width modulation signal Spwm as a control signal. The switch circuit SWb selects the positive power supply voltage + Vcc when the pulse width modulation signal Spwm is on, and selects the ground voltage (0 V, reference voltage) when it is off to generate the pulse width modulation signal + Vpwm. It has become. The pulse width modulation signal + Vpwm corresponds to, for example, the positive voltage + V1 of the control voltage V1, and if smoothed, the waveform becomes a substantially similar shape that closely approximates the positive voltage + V1, but the amplitude is in the range of 0V to + Vcc. It spreads and becomes large, and is applied to the electrode 31b for electrostatic support as a positive voltage V1b through the current limiting circuit 93.

  The switch circuit SWa selects the negative power supply voltage -Vcc when the pulse width modulation signal Spwm is on, and selects the ground voltage (0 V, reference voltage) when the pulse width modulation signal Spwm is off, and selects the ground voltage (0 V, reference voltage) with respect to the pulse width modulation signal + Vpwm. A pulse width modulation signal -Vpwm having an inverted waveform is generated. The pulse width modulation signal -Vpwm corresponds to, for example, the negative voltage -V1 of the control voltage V1, and when smoothed, the waveform becomes a substantially similar shape that closely approximates the negative voltage -V1, but the amplitude ranges from 0V to- The voltage spreads over a range of Vcc and is applied to the electrostatic support electrode 31a as a negative voltage V1a via a current limiting circuit 93.

  Such switch circuits SWa and SWb are easily realized by combining, for example, MOSFET switching transistors, and have a phase relationship with each other from the control output circuit 104 corresponding to the electrostatic support electrode 31 as described above. A certain pulse width modulation signal + Vpwm, -Vpwm is generated, the positive pulse width modulation signal + Vpwm is applied to the electrostatic support electrode 31b, and the negative pulse width modulation signal -Vpwm is applied to the adjacent electrostatic support electrode 31a. It has become so. The same applies to each of the other control electrodes 32 to 37 and 42 to 47.

  On the other hand, the signal detection circuit is the same as that described in the aforementioned prior patent application 3 (see FIGS. 5 and 6). That is, (see FIGS. 9B, 9C, and 10), the applied signal generation circuit 90 that applies the displacement detection application signal V0 to the displacement detection electrodes 38 and 48 amplifies the clock CLKa to generate a rectangular wave voltage. The displacement detection application signal V0 is generated, and the detection signal generation circuit is distributed corresponding to the output stage circuit 108 of the control output circuit 104 such as the control voltages V1 and V12 in the control circuits 102 and 103. Is provided. More specifically, the detection signal generation circuit includes a plurality of common-mode detection circuits 91 attached to the output side of each of the output stage circuits 108, and each of the common-mode detection circuits 91 is connected to the output stage circuit 108 of the attachment destination. The signal component related to the displacement detection application signal V0 is detected by extracting the in-phase component from the negative-phase output.

  In the displacement detection application signal V0 generated by amplifying the clock CLKa in this way, the rising and falling timings of the rectangular wave, which is the sudden change point, coincide with the rising and falling timings of the clock CLKa. Further, as described above, the pulse width modulation signals Spwm and Vpwm generated by the clock synchronous circuit based on the same clock CLKa have the pulse ends coincident with the rising or falling timing of the clock CLKa. Therefore, this control circuit synchronizes the pulse end with the sudden change point of the displacement detection application signal during the pulse width modulation. Since the effective frequency of the control voltage is about several tens of kHz, the frequency of the pulse width modulation signal Vpwm is set to a higher frequency, for example, about several MHz (1 to 5 MHz). (10 to 50 MHz).

  The use mode and operation of the electrostatic levitation gyro apparatus according to the first embodiment will be described with reference to the drawings. 11A to 11G are signal waveform examples.

  Here, in order to clarify the comparison with the above-described example, the application state of the control voltage V1 will be described in detail for the electrode pair 31 among the six pairs of electrostatic rotor-type electrostatic support electrodes. The control voltage V1 is divided into a pair of a positive voltage V1b and a negative phase negative voltage V1a. The positive voltage V1b is applied to the electrostatic support electrode 31b, and the negative voltage V1a is applied to the adjacent electrostatic support electrode 31a. Since it is as described above, the positive voltage V1b applied to the electrostatic support electrode 31b in the electrode pair 31 will be described in detail with reference to the illustrated waveform example. Although the illustration is omitted, the negative voltage V1a is the same except for the reverse phase relationship, and the repeated explanation is omitted, but the other control voltages are also the same.

  If the positive voltage V1b is an analog signal, the positive voltage V1b has an amplitude smaller than the voltage Vcc because the main component is + Vof + Vx obtained by adding the X-axis control voltage component Vx for posture control to the constant offset voltage Vof as described above. Although it changes smoothly and gently (see FIG. 11A), since the control output circuit 104 is PWM, the pulse width modulation signal Vpwm output from the output stage circuit 108 as the main component of the positive voltage V1b is (Refer to FIG. 11 (b)), and changes frequently in a pulse shape with a constant amplitude of the voltage Vcc. The effective value of the X-axis control voltage component is expanded by changing the duty ratio instead of changing the amplitude.

  When the pulse width modulation signal Vpwm is enlarged (see FIG. 11C) and compared with the displacement detection application signal V0 (see FIG. 11D), the displacement detection application signal V0 is the pulse width modulation signal Vpwm. On-off (high / low transition, transition) more frequently, but both the on-timing (pulse start and transition timing) and off-timing (pulse termination and transition timing) of the pulse width modulation signal Vpwm propagate in the electronic circuit. If a slight timing shift due to a delay time or the like is ignored, it coincides with either the on timing or the off timing (abrupt change point) of the displacement detection application signal V0.

  The waveform of the positive voltage V1b of the control voltage V1 is slightly different from the main component pulse width modulation signal Vpwm itself, and is applied from the application signal generation circuit 90 to the displacement detection electrode 38 in the same manner as in the prior patent application 3 described above. The displacement detection application signal V0 is determined by being superimposed on the pulse width modulation signal Vpwm via the gyro rotor 10 and the electrostatic support electrode 31 (see FIG. 11E). In contrast, similarly to the above-mentioned prior patent application 3, the in-phase detection circuit 91 detects the midpoint voltage, and a displacement detection detection signal m1 having a waveform corresponding to the displacement detection application signal V0 is obtained. Is obtained (see FIG. 11F).

  If the transition of the displacement detection application signal V0 and the transition of the pulse width modulation signal Vpwm are asynchronous, as described above, the switching noise of the pulse width modulation signal Vpwm is randomly superimposed on the displacement detection detection signal m1. (See FIG. 7 (g)), in this case (see FIG. 11 (f)), the transition of the displacement detection application signal V0 and the transition of the pulse width modulation signal Vpwm are synchronized. The switching noise of Vpwm is limited to the transition timing of the displacement detection detection signal m1.

Then, such a displacement detection detection signal m1 is sampled by the A / D conversion circuit 65 of the control arithmetic circuit 103 at a stable state timing using the clock CLKb (see FIG. 11 (g)). From the displacement detection value that is input to the arithmetic circuit 103 and used for the control calculation, the influence of switching noise of pulse width modulation is completely eliminated.
Thus, even in this electrostatic levitation type gyro device, accurate displacement detection is performed, and publicly known computations for posture control are appropriately performed based on the displacement detection. Furthermore, angular velocity and acceleration with respect to the inertial space are also appropriately performed. Calculated.

A specific configuration of the electrostatic levitation gyro apparatus according to the second embodiment of the present invention will be described with reference to the drawings. 12A is an overall circuit diagram including a control circuit and a signal detection circuit, and FIG. 12B is a circuit for generating a displacement detection application signal. FIG. 13 is a detailed view of the detection signal generation circuit, FIG. 14 is a detailed view of the control voltage application portion, and FIG. 14B is a detailed view of the control output circuit.
The electrostatic levitation type gyro apparatus is different from that of the first embodiment described above in that the control output circuit 104 is changed to the control output circuit 114, and the applied signal supply circuit generates an applied signal from the applied signal generating circuit 90. The circuit 110 is changed, and the detection signal generation circuit is changed from the in-phase detection circuit 91 to the current detection circuit 64.

Compared with the above-described examples of the prior patent applications 1 and 2 (see FIGS. 1 to 4), the electrostatic levitation gyro device (see FIGS. 12 to 15) is different from the examples of the prior patent application. Similar to the first embodiment, the packaging method is improved (FIG. 1 → FIG. 8), and the control output circuit in the control circuit is improved (FIGS. 2, 4 → FIGS. 12 to 15). It is. The signal detection circuit may be the same as described above (see FIG. 2), and the detection signal generation circuit is a current detection circuit 64 substantially the same as described above (see FIG. 13). The signal supply circuit is changed from the applied signal generating circuit 61 to the applied signal generating circuit 110 (see FIGS. 12 and 14). The gyro mechanism is the same as described above (see FIG. 17).
Hereinafter, the applied signal generation circuit 110 and the control output circuit 114 which have not been described will be described in detail.

  The application signal generation circuit 110 (FIG. 12B) generates the displacement detection application signal V0 and the clock CLKa by dividing the clock CLKc by M and further shaping the waveform. b)), an oscillation circuit that generates a clock CLKc whose frequency is M times higher than that of the clock CLKa, an M-ary counter 111 that advances a count value in accordance with the clock CLKc, and a count value that changes in a sawtooth shape to the M-ary counter ROM 112 which receives 1-bit clock CLKa and a multi-bit triangular wave digital value received from 111, and D / A converter 113 which inputs the digital value and outputs analog displacement detection application signal V0 It is. As a result, the same clock CLKa as in the first embodiment and the same triangular wave displacement detection application signal V0 as the application signal generation circuit 61 described above are generated by the digital circuit.

  As the control output circuit 114 (see FIG. 14B), the control output circuit 104 described above may be used as it is, and the pulse width modulation circuits 105 to 107 in the previous stage are left as they are, but the output stage circuit 108 in the subsequent stage. Is the output stage circuit 115. In this output stage circuit 115, the switch circuit SWb on the positive voltage V1b side remains among the two-input one-output switch circuits SWa and SWb that switch the pulse width modulation signal Spwm as a control signal, but on the negative voltage V1a side. The switch circuit SWa is omitted. The switch circuit SWb selects the positive power supply voltage + Vcc when the pulse width modulation signal Spwm is on and selects the ground voltage 0V when it is off to generate the pulse width modulation signal + Vpwm of the positive voltage V1b. However, the negative voltage V1a is always set to 0V. The same applies to the control output circuit 114 that outputs other control voltages V12 and the like.

  Since this control output circuit 114 does not have a D / A conversion circuit or an analog amplifier, the current mirrors 64a and 64b of the current detection circuit 64 are not directly connected to the control output circuit 114, but the control voltage V1. Are inserted and connected to a positive voltage V1b line and a negative voltage V1a line (see FIG. 13).

  The use mode and operation of the electrostatic levitation gyro apparatus according to the second embodiment will be described with reference to the drawings. 15A to 15G are signal waveform examples.

  Here again, in order to clarify the comparison with the above-described example, as in Example 1, the application state of the control voltage V1 is detailed for the electrode pair 31 among the six pairs of electrostatic rotor-supporting electrodes of the annular rotor type. Describe. The control voltage V1 is divided into a pair of a positive voltage V1b and a negative voltage V1a, the positive voltage V1b is applied to the electrostatic support electrode 31b, and the negative voltage V1a is applied to the adjacent electrostatic support electrode 31a. Is as described above. Of course, the negative voltage V1a is called as such in comparison with the above-described example, but since it does not change to the negative side and is maintained at 0V, the positive voltage V1b and the negative voltage V1a are in reverse phase in terms of voltage level. It also seems unrelated.

  However, since the electrostatic support electrodes 31a and 31b are adjacent to each other and the electric charges of both are balanced by the application of the control voltage V1, the positive voltage V1b and the potential of the intermediate portion of the gyro rotor 10 are taken as a reference. The negative voltage V1a maintains a reverse-phase relationship, and the electrostatic attraction in the X-axis direction with respect to the gyro rotor 10 also corresponds to the control voltage V1 in this case, and in particular, the positive voltage mainly including the pulse width modulation signal Vpwm. Appropriately occurs corresponding to the voltage V1b. Therefore, the positive voltage V1b applied to the electrostatic support electrode 31b in the electrode pair 31 will be described in detail with reference to the illustrated waveform example. Although the repeated explanation is omitted, the other control voltages are the same.

  Again, the pulse width modulation signal Vpwm, which is the main component of the positive voltage V1b, is enlarged (see FIG. 15A) and compared with the displacement detection applied signal V0 and the displacement detection applied current i0 (FIG. 15). (Refer to (b) and (c)), the triangular wave displacement detection applied signal V0 and the rectangular wave displacement detection applied current i0 change more rapidly (bend, invert) than the pulse width modulation signal Vpwm. Displacement detection application if the slight timing shift caused by the propagation delay time in the electronic circuit is ignored for both the on timing (pulse start and transition timing) and off timing (pulse end and transition timing) of the modulation signal Vpwm It coincides with the bending timing of the signal V0 and the inversion timing (abrupt change point) of the displacement detection applied current i0.

  The waveform of the positive voltage V1b of the control voltage V1 is the same as that of the aforementioned prior patent application 2 in that the displacement detection application signal V0 applied from the application signal generation circuit 110 to the displacement detection electrode 38 is the same as that of the gyro rotor 10. It is determined by being superimposed on the pulse width modulation signal Vpwm via the electrode 31 for electric support (see FIG. 15 (d)). Thus, a displacement detection detection current i1 having a waveform corresponding to the displacement detection applied current i0 is obtained (see FIG. 15E).

  If the bending of the displacement detection applied signal V0 and the transition of the pulse width modulation signal Vpwm are asynchronous, the switching noise of the pulse width modulation signal Vpwm is randomly superimposed on the displacement detection detection current i1 as described above. (See FIG. 7 (g)), in this case (see FIG. 15 (e)), since the bending of the displacement detection application signal V0 and the transition of the pulse width modulation signal Vpwm are synchronized, the pulse width modulation signal The switching noise of Vpwm is limited to the inversion timing of the displacement detection detection current i1.

Then, such a detection current i1 for displacement detection is sampled by the A / D conversion circuit 65 of the control arithmetic circuit 103 at a stable state timing using the clock CLKb (see FIG. 15 (f)). From the displacement detection value that is input to the arithmetic circuit 103 and used for the control calculation, the influence of switching noise of pulse width modulation is completely eliminated.
Thus, even in this electrostatic levitation type gyro device, accurate displacement detection is performed, and publicly known computations for posture control are appropriately performed based on the displacement detection. Furthermore, angular velocity and acceleration with respect to the inertial space are also appropriately performed. Calculated.

The electrostatic levitation type gyro apparatus of the present invention whose signal waveform example and signal input circuit are shown in FIG. 16 is different from those of the first and second embodiments described above because the signal input circuit of the control arithmetic circuit 103 is modified. It is a point.
When the signal input circuit 120 samples the displacement detection detection current i1 output from the amplifier or the like 64d or the displacement detection detection signal m1 output from the midpoint voltage detection circuit 92, the input signal i1 (m1) is sampled. Sampling is performed over a plurality of locations, and then digitized.

  Specifically, after the changeover switch 121 is changed over to discharge the capacitor 122, the changeover switch 121 is changed over between the signal connection side and the release side, and a current corresponding to the input signal i1 (m1) is supplied to the capacitor 122. Add together. This addition of current is repeated only for a certain time during which the input signal i1 (m1) is stable in the positive state, and over a plurality of times (four times in the figure). Then, the voltage of the electric charge accumulated in the capacitor 122 is digitized by the A / D conversion circuit 123 at the timing of the clock (CLKb / 4 in the figure) obtained by dividing the clock CLKb by the number of times of addition, and taken into the DSP 66.

  In parallel with this, the changeover switch 124 is changed over to discharge the capacitor 125, and then the changeover switch 124 is changed over between the signal connection side and the release side, and a current corresponding to the input signal i1 (m1) is caused to flow into the capacitor 125. Add together. This addition of current is repeated only for a certain time during which the input signal i1 (m1) is stable in a negative state, and over a plurality of times (four times in the figure). The voltage stored in the capacitor 125 is digitized by the A / D conversion circuit 126 at the timing of the clock (CLKb / 4 in the figure) obtained by dividing the clock CLKb by the number of additions, and this is also taken into the DSP 66.

The DSP 66 uses the adding means 127 embodied in the program to invert one of the two digital values so that they are leveled and averaged, and then add them to ½.
In this electrostatic levitation type gyro device, the displacement detection value obtained in this way as a digital value is mitigated / suppressed by instantaneous noise leveling and averaging over a predetermined time period. More stable posture control is performed.

[Others]
In each of the above embodiments, an apparatus package including a plate-shaped cap 71 and a box-shaped box 72 and an apparatus package including a cap-shaped cap 71 and a disk-shaped bottom plate 72 are used. The device package is not limited to this. The device package may be any container that can be hermetically sealed. The vacuum suction port 76 is not limited to the front, but may be located anywhere in the package. When evacuation is not required as in assembly in a vacuum atmosphere, it is not necessary to form the vacuum suction port 76.

  In the first embodiment, the elastic support member 98 is provided between the base 73 and the pin 74. However, the elastic support of the base 73 is not limited thereto. For example, the elastic support member is connected to the base 73. It may be interposed between the packages 71 and 72. The elastic support member is not limited to a leaf spring, and may be made of an elastic member such as a coil spring or silicon rubber, or a combination thereof.

  Various modifications can be made to the signal detection circuit described above. For example, a sequential selection switching circuit may be provided upstream of the A / D conversion circuit 65 to reduce the number of A / D conversion circuits 65. Note that the A / D conversion circuit 65 and the like existing between the current detection circuit 64 and the DSP 66 may be a part of the control arithmetic circuit 103 as described above. Even if it forms a part of the detection circuit, there is no inconvenience even as an interface unit belonging to both. The DSP 66 of the control arithmetic circuit 103 and the DSP 67 of the rotor control circuit 102 may be provided separately as described above, but may be combined into a DSP in which both programs are installed.

(A) is a front view of the device, (b) is a plan view of the device with the lid removed, (c) is a longitudinal sectional perspective view, and (d) is a device mounting. It is a perspective view which shows a condition. (A) is an overall circuit diagram including a signal detection circuit, (b) is a displacement detection application signal generation circuit, and (c) is a current detection circuit. (A) is a signal input circuit of the constraint control system, and (b) is a signal input circuit of the rotor drive system. (A) is a detailed view of a control voltage application portion, and (b) to (f) are all signal waveform examples. (A) is an entire circuit diagram including other signal detection circuits, (b) is a displacement detection application signal generation circuit, and (c) is a detection signal generation circuit. (A) is a detailed view of the control voltage application portion and the detection signal generation circuit, and (b) to (e) are signal waveform examples. It is explanatory drawing of the solution subject of this invention, (a) is a detailed figure of the conventional control output circuit, (b) is the characteristic graph which took the applied voltage on the horizontal axis, and took the electrostatic attraction on the vertical axis, (c). Is a detailed diagram of a control output circuit with pulse width modulation, (d) is a characteristic graph in which the horizontal axis indicates the modulation factor and the vertical axis indicates the electrostatic attractive force, and (e) to (g) are examples of signal waveforms. It is. About Example 1 of this invention, (a) is a top view of the place which removed the cover, (b) is a longitudinal front view. (A) is an overall circuit diagram including a control circuit and a signal detection circuit, (b) is a displacement detection application signal generation circuit, and (c) is a detection signal generation circuit. (A) is a detailed view of a control voltage application part, (b) is a detailed view of a control output circuit. (A) to (g) are all signal waveform examples. In Embodiment 2 of the present invention, (a) is an overall circuit diagram including a control circuit and a signal detection circuit, and (b) is a circuit for generating a displacement detection application signal. It is a detailed diagram of a detection signal generation circuit. (A) is a detailed view of a control voltage application part, (b) is a detailed view of a control output circuit. (A) to (g) are all signal waveform examples. In Example 3 of the present invention, (a) is an example of a signal waveform, and (b) is a signal input circuit of a constraint control system. The mechanism part of the conventional electrostatic levitation type gyro is shown, (a)-(c) is an example of a disk-shaped rotor type, (d) and (e) are examples of an annular rotor type, (a) and ( d) is a longitudinal front view, and (b), (c), and (e) are exploded perspective views of built-in components. Regarding a conventional signal detection circuit, (a) is an overall circuit diagram in which a signal detection circuit is added to a control circuit or the like, (b) is a detailed connection diagram of a control output circuit, (c) is a part of a signal input circuit, (D) and (e) are voltage distribution examples.

Explanation of symbols

10 Gyro rotor (gyro mechanism)
20 Gyro case (Gyro mechanism)
21 Upper bottom member (gyro case, gyro mechanism)
22 Lower bottom member (gyro case, gyro mechanism)
23 Spacer (gyro case, gyro mechanism)
31-36 Electrostatic support electrodes (attitude control electrodes, control electrodes, restraint control system)
37 Rotor drive electrode (rotary electrode, rotor drive system)
38 Electrode for displacement detection (detection electrode, displacement detection system)
41-46 Electrostatic support electrodes (posture control electrodes, control electrodes, restraint control system)
47 Rotor drive electrode (rotary electrode, rotor drive system)
48 Electrode for displacement detection (detection electrode, displacement detection system)
51 Current detection circuit (displacement detection system)
52 Rotor control circuit (control circuit, rotor drive system)
53 Control arithmetic circuit (control circuit, constraint control system)
54 Control output circuit (control circuit, restraint control system)
61 Application signal generation circuit (application signal supply circuit, signal detection circuit, displacement detection system)
62 Rotor control circuit (control circuit, rotor drive system)
63 Control arithmetic circuit (control circuit, constraint control system)
64 Current detection circuit (detection signal generation circuit, signal detection circuit, displacement detection system)
64a, 64b Current mirror (current inversion circuit)
65 A / D conversion circuit (signal input circuit, signal detection circuit + control arithmetic circuit)
66 DSP (digital signal processor, control arithmetic circuit, restraint control system)
67 DSP (digital signal processor, control arithmetic circuit, rotor drive system)
70 Gyroscope (Electrostatic Levitation Gyroscope)
71 Cap (lid, vacuum container, hermetically sealed package)
72 boxes (box, can, vacuum container, hermetically sealed package)
73 Base (Glass substrate, insulating substrate, mechanism and circuit board)
74 pins (lead, external connection terminal)
75 Getter (Vacuum maintenance member)
76 Vacuum suction port (through hole + sealing plug)
77, 78 IC (current detection circuit, control output circuit, etc.)
80 Printed circuit board (circuit printed circuit board, gyro device mounting circuit board)
81 Regulator IC (Power supply circuit)
82 Smoothing capacitor (power circuit)
90 Application signal generation circuit (application signal supply circuit, signal detection circuit, displacement detection system)
91 In-phase detection circuit (detection signal generation circuit, signal detection circuit, displacement detection system)
92 Midpoint voltage detection circuit (common-mode detection circuit)
93 Current limiting circuit (low-pass filtering, common-mode detection circuit)
97 Gyro Device (Electrostatic Levitation Type Gyro Device)
98 Elastic support member 99 Bonding wire 102 Rotor control circuit (control circuit, rotor drive system)
103 Control arithmetic circuit (control circuit, constraint control system)
104 Control output circuit (PWM, control circuit)
105 Latch (clock synchronous PWM modulation rate holder)
106 N-ary counter (clock synchronous sawtooth wave generator)
107 comparator (comparator, switch control signal generator)
108 Output stage circuit (switch circuit)
110 Application signal generation circuit (application signal supply circuit, signal detection circuit, displacement detection system)
114 Control output circuit (PWM, control circuit)
115 Output stage circuit (switch circuit)
120 signal input circuit (control circuit, constraint control system)
121 selector switch (selection input circuit, sampling circuit)
122 capacitor (hold circuit, sampling circuit)
123 A / D conversion circuit (sampling circuit)
124 selector switch (selection input circuit, sampling circuit)
125 capacitor (hold circuit, sampling circuit)
126 A / D conversion circuit (sampling circuit)
127 addition means (averaging means, leveling means, integration means)

Claims (3)

  A gyro case in which the gyro rotor is electrostatically levitated and rotatably incorporated, and among the plurality of electrodes formed on the gyro rotor, the electrostatic support electrode and the rotation drive electrode are used for attitude control and rotation drive of the gyro rotor. And a control circuit that generates and applies control voltages for each of the control signals, and an application signal supply that applies a displacement detection application signal for detecting relative displacement between the gyro rotor and the gyro case to a part of the plurality of electrodes. A signal component related to the displacement detection application signal is detected by passing through a circuit and a displacement detection electrode to which the control voltage is not applied among the plurality of electrodes, and a detection signal for displacement detection is generated and supplied to the control circuit In the electrostatic levitation gyro apparatus including a detection signal generation circuit to be sent, the application signal supply circuit converts the displacement detection application signal into the displacement detection signal. The detection signal generation circuit is provided in a distributed manner corresponding to the control voltage output stage circuit in the control circuit, and the control circuit generates the control voltage. An electrostatic levitation type gyro apparatus which performs pulse width modulation and synchronizes a pulse end with a sudden change point of the displacement detection application signal during the pulse width modulation.   The detection signal generation circuit includes a plurality of current detection circuits attached to the output stage circuit in a distributed manner, and each of the current detection circuits detects the displacement of the output current of the output stage circuit at the attachment destination. 2. The electrostatic levitation gyro apparatus according to claim 1, wherein a signal component related to the applied signal is detected.   The output stage circuit generates at least one of the control voltages having a phase opposite to that for attitude control and applies it to an adjacent one of the plurality of electrodes, and the detection signal generation circuit includes Each of the output stage circuits has a plurality of common-mode detection circuits attached to the output side, and each of the common-mode detection circuits extracts the common-mode component from the negative-phase output of the output stage circuit to which the output stage circuit is attached. 2. The electrostatic levitation gyro apparatus according to claim 1, wherein a signal component relating to the detection application signal is detected.

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