JP2005140709A - Electrostatic levitation-type gyro device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate a bad influence by switching noise induced in a detection signal by performing the PWM of a control voltage for improving control capacity by fully utilizing a supply voltage Vcc. <P>SOLUTION: A pulse width modulation means is introduced into a control arithmetic circuit 63 and a control output circuit 64. A triangular signal f0 is generated by an application signal generation circuit 65, which is time-shared by a selection circuit 66 to generate application signals f1-f12 for detecting displacement for superposing on respective control voltages V1-V12. When generating the signals, the pulse end of the control voltages V1-V12 is synchronized to the bending points of the application signals f1-f12 for detecting displacement, thus avoiding the influence of switching noise and performing the PWM of the control signal in an embodiment for dispensing with frequency discrimination. <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. 8 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 which is relatively simple and clear (see FIGS. 8D and 8E), 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. 8D, 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. 9A 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 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. 9B). 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. 9A) 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. 9C), the displacement detection detection signal Vp and the sine are connected to the cascade 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.

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

  In such a signal detection circuit of an electrostatic levitation gyro (see FIG. 10A), when the gyro rotor 10 is stationary at a neutral position apart from the rotation about the Z axis, the electrostatic support electrodes 31 and 41 are used. When the constant offset voltage applied to V is Vof and the X-axis control voltage component calculated and changed for attitude control is Vx, the main component (+ V1) output from the control output circuit 54 of the positive voltage V1b is + Vof + Vx. The main component (-V1) of the negative voltage V1a is set to -Vof-Vx, and a displacement detection application signal f1 (sine wave in the figure) having a high frequency and a small amplitude is superimposed on them in phase. The main component (+ V12) of the positive voltage V12b is set to + Vof−Vx, and the main component (−V12) of the negative voltage V12a is set to −Vof + Vx. These are also for another displacement detection having a high frequency and a small amplitude. The applied signal f12 (sine wave in the figure) is superimposed in phase.

  Since the displacement detection application signals f1 to f12 are superimposed on the control voltages V1, V12 and the like in this way, the sum of the two voltages cannot exceed the power supply voltage Vcc of the control output circuit 54. The power supply voltage Vcc is assigned to the amplitude voltage Vf of the applied signal f1 and the maximum voltage V1m of the control voltage V1 (see FIG. 10B). For this reason, when the control voltage is increased, the displacement detection application signal is decreased, and when the displacement detection application signal is increased, the control voltage is decreased. Therefore, it is not possible to increase only one of them for the convenience of either one. Thus, the method of superimposing the displacement detection application signal on the control voltage has a limitation that the range of the power supply voltage that can be effectively used for the control voltage is limited by the amplitude voltage Vf of the displacement detection application signal f1.

  With regard to this restriction, for example, an inconvenience occurs when the electrostatic levitation gyro is miniaturized. Specifically, when the diameter of the gyro rotor 10 that was conventionally about 5 mm is reduced to about 1 mm, the capacity of the plurality of electrodes 31 to 48 is reduced, and the input current Ip that is the detection target of the current detection circuit 51, This is the source of the displacement detection detection signal Vp, but the detection current Ip 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 V1m of the control voltage V1, so that the balance of allocation to both is undesirably broken (FIG. 10 (c)). reference). The same applies to other displacement detection application signals and control voltages.

  There are other restrictions. In the electronic circuit of the conventional electrostatic levitation gyro described above, an analog circuit is used for the control output circuit 54, and in a typical configuration, for example, it is applied to the electrostatic support electrode 31 (that is, the adjacent electrodes 31a and 31b). In the configuration for outputting the control voltage V1 (that is, positive and negative voltages V1a and V1b) (see FIG. 10D), a non-inverting amplifier (Amp, signal amplifier) that operates with a positive power supply (+ Vcc) and generates the positive voltage V1b. ), A level shifter (level conversion circuit) that shifts the signal level from positive to negative, and an inverting amplifier (Amp, signal amplifier) that operates with a negative power supply (−Vcc) to generate the negative voltage V1a. It takes every time. 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. 10 (e)), 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. More specifically, the entire range of the maximum voltage V1m of the control voltage V1 cannot be effectively used for the X-axis control voltage component Vx that changes for posture control. 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 restriction, the use of a pulse width modulation (PWM) method can be considered. For example (see FIG. 10 (f)), a switch circuit SWb (see FIG. 10 (f)) that switches the generated signal of the control arithmetic circuit 53 as a control signal by performing pulse width modulation with a pulse width modulation circuit (PWM) to turn it on / off (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. 10 (g)), 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, since the PWM of the control voltage has a side effect of inducing undesired switching noise, large switching noise is superimposed on the displacement detection application signals f1 to f12 superimposed on the control voltages V1 to V12. It will be done. As a result, the waveform of the detection signal Vp for displacement detection is disturbed, the detection accuracy is lowered, and the control performance is lowered.
Therefore, in order to obtain the advantage of improving the control capability by using the power supply voltage Vcc without waste, the control voltage is converted to PWM so that the adverse effect due to the switching noise induced by the detection signal is eliminated. It is a technical problem to devise the configuration of the detection circuit and the control circuit.

  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, A displacement detection application signal for detecting a relative displacement with respect to the gyro case is superimposed on the control voltage and applied to the plurality of electrodes (specifically, only the electrostatic support electrode of the plurality of electrodes or the static electricity). An applied signal supply circuit to be applied to both the electro-support electrode and the rotation drive electrode, and the displacement from the displacement detection electrode to which the control voltage is not applied among the plurality of electrodes. In the electrostatic levitation gyro apparatus including a detection signal generation circuit that detects a signal component related to the outgoing application signal, generates a detection signal for displacement detection, and sends the detection signal to the control circuit, the application signal supply circuit includes: A voltage signal in the form of a triangular wave is used as the displacement detection application signal, and when the signal is superimposed on the control voltage, the superimposition destination is time-divided, and the control circuit performs pulse width modulation when generating the control voltage. In addition, in the pulse width modulation, the pulse end is synchronized with the bending point of the displacement detection application signal.

  Further, the electrostatic levitation gyro apparatus of the present invention (Solution means 2) includes a gyro case in which a gyro rotor is electrostatically levitated and rotatable, and an electrostatic support among a plurality of electrodes formed on the gyro case. A control circuit that generates and applies control voltages for attitude control and rotation drive of the gyro rotor to the electrodes and the rotation drive electrode, and displacement detection for detecting relative displacement between the gyro rotor and the gyro case An applied signal supply circuit for applying an applied signal to the electrostatic support electrode (or both of the electrostatic support electrode and the rotation drive electrode), and displacement detection of the plurality of electrodes to which the control voltage is not applied A detection signal generation circuit that detects a signal component related to the displacement detection application signal from the electrode for generating 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 uses a triangular-wave voltage signal as the displacement detection application signal and applies it to the electrostatic support electrode (or the electrostatic support electrode and the rotational drive). The application destination is switched in a time-sharing manner when applied, and the control circuit performs pulse width modulation when generating the control voltage, and the pulse is modulated when the pulse is modulated. And the pulse end is synchronized with the bending point of the displacement detection application signal.

In such an electrostatic levitation gyro device of the present invention (Solution 1), the control voltage generated by the control circuit is subjected to pulse width modulation, so that the control voltage and the electrostatic attractive force are Since the relationship is linearized, the power supply voltage can be used without waste to improve the control capability, the output stage circuit can be simplified, and energy waste can be reduced.
In addition, a triangular wave voltage signal is used as the displacement detection application signal superimposed on the control voltage, and the pulse end is synchronized with the bending point of the displacement detection application signal when modulating the pulse width of the control voltage. As a result, the pulse end of the control voltage approaches the bending point of the displacement detection application signal so that it can be regarded as overlapping. It is limited to the bending point of the detection application signal.

  When the voltage waveform of the displacement detection application signal is a triangular wave, the displacement detection detection signal detected by the displacement current from the displacement detection electrode via the control electrode becomes a rectangular wave, and the bending detection point of the displacement detection application signal By the way, since the change is high / low, the switching noise associated with the PWM control voltage is limited to the place where the displacement detection detection signal changes high / low, that is, the transition state is originally transitional. Therefore, by using sampling at other stable state timings, the use of the transition state is easily avoided, and the influence of switching noise is eliminated.

Furthermore, when the displacement detection application signal is superimposed on the control voltage, the superimposition destination is also time-shared, so that frequency discrimination is not required if the corresponding time-division processing is performed on the displacement detection application signal. Therefore, even if the displacement detection application signal includes a harmonic wave unlike a sine wave, it is possible to accurately distinguish and detect the capacitance of each of the plurality of control electrodes even if it is a triangular wave shape that is difficult to discriminate in frequency. The relative displacement between the rotor and the gyro case is accurately detected.
Therefore, according to the present invention, the control voltage is PWMed in a manner that avoids the influence of switching noise and eliminates the need for frequency discrimination. Therefore, the electrostatic levitation gyro that can use the power supply voltage without waste and has high control capability An apparatus can be realized.

Further, in the electrostatic levitation gyro apparatus of the present invention (Solution means 2), the PWM of the control voltage, the triangular wave of the displacement detection application signal, and the synchronization of both are succeeded in the above-mentioned Solution 1. In addition to this, the time-division technique is not limited to switching the application destination of the displacement detection application signal, but is also applied to the switching between the control voltage pulse application and the displacement detection application signal triangular wave application. Yes.
As a result, even if the control voltage application destination and the displacement detection application signal application destination are the same control electrodes as in the past, the active components of both signals will not be superimposed. It is possible to assign the entire range of voltages.

Then, the displacement detection application signal, which tends to be suppressed to be smaller than the control voltage at the time of superimposition, is greatly improved relatively.
Therefore, according to the present invention, the control voltage is converted to PWM in such a manner that the influence of switching noise is avoided, frequency discrimination is not required, and allocation of the power supply voltage to the control voltage and the detection signal is also unnecessary. It is possible to realize an electrostatic levitation gyro apparatus that can use voltage without waste and has high control ability and detection ability.

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 Examples 1 to 4 below.
The embodiment 1 shown in FIGS. 1 to 4 embodies the above-described solution 1 (claim 1 at the beginning of the application), and the embodiment 2 shown in FIG. 5 is a modification thereof. Further, the third embodiment shown in FIG. 6 embodies the above-described solution 2 (claim 2 at the beginning of the application), and the fourth embodiment shown in FIG. 7 is a modification thereof.

In the drawings, the same components as those mentioned in the column of the premise technology in the column of the background technology and the components referred to in the column of the conventional technology in the column of the background technology are denoted by the same reference numerals. Therefore, since the gyro mechanism part described in the column of the premise technology in the column of the background art is also used as it is in each of the following embodiments, the repeated explanation is omitted, and the difference from the prior art is described below. The explanation will be focused on.
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. 1A and 1B show the structure of an electronic circuit unit, where FIG. 1A is an overall circuit diagram including a control circuit and a signal detection circuit, FIG. 1B is a detailed connection diagram of a control output circuit, and FIG. (D) is a frequency dividing circuit for generating a time division clock. 2A is a detailed view of the control output circuit, and FIG. 2B is a signal input circuit.

The electronic circuit of the electrostatic levitation gyro apparatus is different from the conventional example of FIG. 9 described above in that an application signal supply circuit that supplies displacement detection application signals f1 to f12 in the signal detection circuit is applied signal generation circuit 65. And the control circuit 53 and the control output circuit 54 are converted to PWM to form the control operation circuit 63 and the control output circuit 64 (FIG. 1 ( a)).
The displacement detection application signal f1 is superimposed on the control voltage V1 and applied to the electrostatic support electrode 31, and the detection is performed by the current detection circuit 51 from the displacement detection electrodes 38 and 48 in the conventional manner. Yes (see FIGS. 1A and 1B). Other displacement detection application signals f2 to f12 are also superimposed on the control voltages V2 to V12 and applied to the electrostatic support electrodes 32 to 36 and 41 to 46, respectively. Is performed (see FIG. 1A).

  The applied signal generating circuit 65 (see FIG. 1C) is provided with a pair of constant current circuits in the reverse direction to generate a triangular wave voltage signal f0 that is a source of the displacement detection applied signals f1 to f12, Current sending and current suction are alternately repeated by a switch or the like that switches at CLKa. The triangular wave signal f0 generated by such a constant current circuit pair and the switch circuit is sent to the selection circuit 66 via an appropriate coupling capacitor 61a as shown in the figure. Note that the frequency of the clock CLKa is, for example, about several MHz to several tens of MHz. This is a frequency that is much higher than several tens of kHz that affects the motion of the gyro rotor 10, and is higher than the pulse frequency of 1 MHz, which will be described in detail later.

  The selection circuit 66 (see FIG. 1A) is composed of a single input and a number of output destinations (specifically, twelve) demultiplexers, selectors, etc., and receives a triangular wave signal f0 and outputs it. The destination is switched. The switching is performed in order in synchronization with the rise or fall of the clock CLKd. Specifically, a certain period of the clock CLKd is applied to the electrostatic support electrode 31 by superimposing the triangular wave signal f0 as the displacement detection application signal f1 on the control voltage V1, and the next period of the clock CLKd is a triangular wave. When the signal f0 is superimposed on the control voltage V2 as the displacement detection application signal f2 and applied to the electrostatic support electrode 32, the same applies to the displacement detection application signals f3 to f12, and then the displacement detection application signal f1. Go back to repeat the same thing.

  The clock CLKd (see FIG. 1D) is generated by dividing the clock CLKa by L by the frequency divider 67 in order to synchronize the switching timing of the selection circuit 66 with the clock CLKa, and is supplied to the selection circuit 66. It is like that. The frequency division value L may be an appropriate positive integer as long as it satisfies the requirement that the frequency of the clock CLKd be higher than several tens of kHz that affects the motion of the gyro rotor 10.

In addition, the displacement detection application signal f1 is superimposed on the positive and negative control voltages + V1 and -V1 in phase and applied to the adjacent electrodes 31a and 31b in phase. The same applies to the other displacement detection application signals f2 to f12.
Such a selection circuit 66 is a superposition destination switching circuit / time division circuit that switches the superposition destination in a time division manner when superimposing the triangular wave signal f0 on the control voltages V1 to V12.

  Further, with respect to the control circuit (see FIG. 2), the calculation contents for attitude control in the control calculation circuit 63 are the same as those in the control calculation circuit 53, but in order to perform pulse width modulation when generating the control voltages V1 to V12, control is performed. The part that sent the analog signal to the output circuit 54 has been modified to send the digital signal to the control output circuit 64. Specifically (see the broken line portion in FIG. 2A), 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 64 as a digital value.

The control output circuit 64 (see FIG. 2 (a)) is a digital circuit for converting the PWM modulation rate into a pulse width modulation signal Spwm having a logic signal level in order to perform pulse width modulation when generating the control voltage V1 or the like. A pulse width modulation circuit 64b for switching, and an output stage circuit 64a for converting a pulse width modulation signal Spwm of a logical signal level into a pulse width modulation signal pair Vpwm (+ Vpwm, -Vpwm) at a voltage Vcc level. . There is no D / A conversion circuit or analog amplifier.
The pulse width modulation circuit 64b is synchronized with the clock CLKa in the same manner as the application signal generation circuit 65 in order to synchronize the pulse ends with the bending points of the displacement detection application signals f1 to f12 in the pulse width modulation of the control voltages V1 to V12. It is supposed to work.

  More specifically, the pulse width modulation circuit 64b includes a latch 64c that holds the PWM modulation rate received from the control arithmetic circuit 63, and an N-ary counter that advances the count value at the rising or falling edge of the clock CLKa and changes it in a sawtooth shape. 64d and a counter that receives the count value from the N-ary counter 64d and receives the PWM modulation rate from the latch 64c, compares the count value with the PWM modulation rate, and generates a binary pulse width modulation signal Spwm (on / off signal) 64e.

  Similarly to the N-ary counter 64d, the latch 64c 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 64e coincides with the rise or fall of the clock CLKa. It has become. When 100% PWM modulation is used, the control arithmetic circuit 63 performs conversion so that the maximum value of the PWM modulation rate matches N of the N-ary counter 64d. 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 64a 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 ranges from 0V to + Vcc. And is applied to the electrostatic support electrode 31b as the positive voltage V1b after the displacement detection application signal f1 is superimposed.

  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 if smoothed, the waveform becomes a substantially similar shape that closely approximates the negative voltage -V1, but the amplitude is 0V to It spreads over the range of −Vcc, and is applied to the electrostatic support electrode 31a as the negative voltage V1a after the displacement detection application signal f1 is superimposed.

  Such switch circuits SWa and SWb are easily implemented by combining, for example, MOSFET switching transistors. As described above, the control output circuit 64 corresponding to the electrostatic support electrode 31 has a phase relationship opposite to each other. 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. On the other hand, the displacement detection application signal f1 is applied in phase to the adjacent electrodes 31a and 31b. The same applies to each of the other control electrodes 32 to 37 and 42 to 47.

  The signal input portion in the control arithmetic circuit 63 (see FIG. 2B) is also modified in accordance with the triangular wave and time-division application of the displacement detection application signals f1 to f12. That is, when the displacement detection application signals f1 to f12 are triangular waves, the input current Ip of the current detection circuit 51 and the displacement detection detection signal Vp are rectangular waves, so that the displacement detection detection signal Vp is converted by the A / D conversion circuit 63a. It is digitally processed by taking it into a digital operation unit such as a DSP 63b (digital signal processor) shown in the figure and a microprocessor (not shown). The A / D conversion circuit 63a is sampled and sampled at the timing of the clock CLKb and is 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 DSP 63b inputs the digital value of the detection signal Vp for displacement detection every time the clock CLKb, and for example interrupts the rising or falling timing of the clock CLKd generated from the clock CLKa by the frequency dividing circuit 67 and used by the selection circuit 66. Detect at. The digital value of the displacement detection detection signal Vp is distributed to the detection value temporary storage areas g1 to g12 while switching the distribution destination in synchronization with the clock CLKd. Specifically, when the selection circuit 66 uses the triangular wave signal f0 as the displacement detection application signal f1, the detection value temporary storage area g1 is used as a distribution destination of the displacement detection detection signal Vp, and a digital value is temporarily stored therein. deep. When the selection circuit 66 uses the triangular wave signal f0 as the displacement detection application signal f2, the detection value temporary storage area g2 is used as a distribution destination of the displacement detection detection signal Vp, and a digital value is temporarily stored therein.

  Similar distribution is performed at other timings of the clock CLKd so that the digital values of the displacement detection detection signals Vp corresponding to the displacement detection application signals f1 to f12 are distributed to the storage areas g1 to g12. It has become. Each storage area g1 to g12 is continuously input with data for a maximum of L times each time it becomes a distribution destination. Therefore, although it is not essential, the first and last data are usually used to suppress the influence of noise. The process of ignoring and taking the average value of the middle part is also performed. Since the digital values in these detection value temporary storage areas g1 to g12 reflect the capacitances of the electrostatic support electrodes 31 to 36 and 41 to 46, respectively, the subsequent displacement calculation or the like, that is, the gyro rotor 10 and the gyro case 20 The calculation of the relative displacement and the calculation of the posture control based on the relative displacement are performed by a known conventional method.

The use mode and operation of the electrostatic levitation gyro apparatus according to the first embodiment will be described with reference to the drawings. FIGS. 3A to 3G and FIGS. 4A to 4H are examples of signal waveforms.
Here too, in order to clarify the comparison with the above-described examples, the details of the electrode pair 31 of the six pairs of electrostatic support electrodes of the annular rotor type, focusing on the application state of the control voltage V1 and the displacement detection application signal f1. Describe.

  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. The negative voltage V1a is the same except for the negative phase relationship of the main component (Vpwm). Other control voltages are the same, although repeated descriptions and illustrations are omitted. As described above, the displacement detection application signal f1 is applied in phase to the adjacent electrostatic support electrodes 31a and 31b, which will be described in detail with reference to the waveform examples shown in the drawings. The other displacement detection application signals f2 to f12 are also applied to the corresponding control electrodes in the same phase, so that repeated explanations and illustrations are omitted, and the corresponding changes are made in accordance with triangular wave formation and time division application. This is illustrated in detail, and will be described in detail with reference to the waveform example.

  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. 3A), since the control output circuit 64 is converted to PWM, the pulse width modulation signal Vpwm output from the output stage circuit 64a as the main component of the positive voltage V1b is (Refer to FIG. 3 (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.

  Further, since the displacement detection application signals f1 to f12 are generated by time-sharing the triangular wave signal f0 (see FIG. 3C), the displacement detection application signal f1 is one cycle at the clock CLKd. A triangular wave appears only during the L period at the clock CLKa, and after that, there is no signal state (0 V) for a while. When the displacement detection application signal f1 becomes a no-signal state, a triangular wave having the same period appears only in the displacement detection application signal f2 (see FIG. 3D), and when the displacement detection application signal f2 becomes a no-signal state. A triangular wave with the same period appears only in the displacement detection application signal f3 (see FIG. 3E), and when the displacement detection application signal f3 becomes no signal, a triangular wave with the same period appears only in the displacement detection application signal f4. In the same manner, triangular waves appear in order in the displacement detection application signals f5 to f12 (see FIG. 3G), and the displacement detection application signal f12 is in a no-signal state. Then, it returns to the displacement detection application signal f1 and a triangular wave with the same period appears only there (see FIG. 3C). In this way, the displacement detection application signals f1 to f12 are superimposed on the control voltages V1 to V12, respectively, not only for the superimposition destination but also for the effective component superposition timing.

  When the pulse width modulation signal Vpwm and the displacement detection application signal f1 are enlarged (see FIGS. 4A and 4B and FIGS. 4C and 4D), the displacement is detected. The applied signal f1 is bent more frequently than the pulse width modulation signal Vpwm, but the on timing (pulse start and transition timing) and off timing (pulse end and transition timing) of the pulse width modulation signal Vpwm are both within the electronic circuit. If a slight timing shift due to the propagation delay time of the signal is ignored, it coincides with one of the bending timings of the displacement detection application signal f1.

  The waveform of the positive voltage V1b in the control voltage V1 is the same as the positive pulse width modulation signal + Vpwm when the displacement detection application signal f1 is in the no-signal state, but is superimposed when the displacement detection application signal f1 is a triangular wave. Therefore, it is slightly different from the positive pulse width modulation signal + Vpwm itself (see FIG. 4E). The waveform of the negative voltage V1a in the control voltage V1 is the same as the negative pulse width modulation signal −Vpwm when the displacement detection application signal f1 is in the no-signal state, but the displacement detection application signal f1 is a triangular wave. Since this is sometimes a superimposed waveform, it is somewhat different from the negative pulse width modulation signal -Vpwm itself (see FIG. 4 (f)).

  When the control voltage V1, that is, the negative voltage V1a and the positive voltage V1b are applied to the electrostatic support electrode 31, that is, the adjacent electrostatic support electrodes 31a and 31b, the reverse-phase pulse width modulation signal Vpwm, that is, the positive pulse is applied. The width modulation signal + Vpwm and the negative pulse width modulation signal −Vpwm cause an electrostatic attractive force (electrostatic support force) on the electrostatic support electrode 31, but the in-phase displacement detection application signal f <b> 1 is the electrostatic support electrode. No electrostatic attraction is generated in 31. Therefore, the displacement detection application signal f1 is used exclusively for detecting the capacitance of the electrostatic support electrode 31 and thus detecting the relative displacement between the gyro rotor 10 and the gyro case 20 without affecting the attitude control.

  Since the displacement current of the electrostatic support electrode 31 due to the pulse width modulation signal Vpwm of the opposite phase remains as accumulated charge there, it does not reach the displacement detection electrodes 38 and 48, so the current detection circuit 51. However, the displacement current of the electrostatic support electrode 31 due to the in-phase displacement detection applied signal f1 is not limited to the input current Ip or the displacement detection detection signal Vp. , 48, it becomes the input current Ip of the current detection circuit 51, and is thus detected as a rectangular wave-shaped displacement detection detection signal Vp (see FIG. 4G).

  If the bending of the displacement detection applied signal f1 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 signal Vp as described above. However, in this case (see FIG. 4G), since the bending of the displacement detection applied signal f1 and the transition of the pulse width modulation signal Vpwm are synchronized, the switching noise of the pulse width modulation signal Vpwm is detected as displacement. It is limited to the transition timing of the detection signal Vp for use, that is, the rising or falling timing of the rectangular wave.

Then, such a displacement detection detection signal Vp is sampled by the A / D conversion circuit 63a of the control arithmetic circuit 63 at a stable state timing using the clock CLKb (see FIG. 4 (h)). The displacement detection value (g1) input to the DSP 63b of the arithmetic circuit 63 and used for the control calculation completely eliminates the influence of the switching noise of the pulse width modulation. The other displacement detection application signals f2 to f12 are also time-divisioned and thus have different sampling timings, but similarly displacement detection values (g2 to g12) that are not affected by switching noise are obtained.
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 difference between the electrostatic levitation type gyro apparatus of the present invention shown in FIG. 5 as an applied signal generating circuit, a control output circuit, and signal waveform examples is different from that of the first embodiment described above. The circuit 65 is digitized to become an applied signal generation circuit 75, and the control output circuit 64 using the positive and negative power supply voltages + Vcc and -Vcc is modified so as to use only the positive power supply voltage + Vcc.

  The applied signal generation circuit 75 (see FIG. 5A) divides the clock CLKc by M and further shapes the waveform to generate the triangular wave signal f0 and the clock CLKa. For this reason, the frequency is higher than that of the clock CLKa. Generates an M-times higher clock CLKc, an M-ary counter 75a that advances a count value in accordance with the clock CLKc, and receives a count value that changes in a sawtooth form from the M-ary counter 75a to generate a 1-bit clock CLKa A ROM 75b for outputting a multi-bit triangular wave digital value and a D / A converter 75c for inputting the digital value and outputting an analog triangular wave signal f0 are provided. As a result, the same clock CLKa as in the first embodiment and the same triangular wave signal f0 (the original signal of the displacement detection application signals f1 to f12) as generated by the application signal generation circuit 65 described above are generated by the digital circuit. The

  In the control output circuit 64 (see FIG. 5A), the pulse width modulation circuit 64b in the previous stage remains unchanged, but the output stage circuit 64a in the subsequent stage is disconnected from the negative power supply voltage -Vcc. That is, in the output stage circuit 64a, 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 0 V when it is off to generate the pulse width modulation signal + Vpwm of the positive voltage V1b, as described above. However, the pulse width modulation signal + Vpwm of the negative voltage V1a is always set to 0V. The same applies to the control output circuit 64 that outputs other control voltages V12 and the like.

  In this case, the application state of the control voltage V1 is described in detail for the electrode 31 among the six pairs of electrostatic support electrodes of the annular rotor type. The control voltage V1 is divided into a pair of the positive voltage V1b and the negative voltage V1a. As described above, 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. As described above, the displacement detection application signal f1 is included in the positive and negative voltages V1b and V1a in phase. However, the negative voltage V1a is called as such in comparison with the above-described example, but it does not change to the negative side except for the case where the triangular wave component of the displacement detection application signal f1 is superimposed, and is set to 0V. Therefore, even if the superposition of the displacement detection application signal f1 is ignored, it seems that the positive voltage V1b and the negative voltage V1a are not in a reverse phase relationship in terms of the voltage level.

  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. Although the repeated explanation is omitted, the other control voltages are the same.

  Here, the positive voltage V1b (see FIG. 5B) and the negative voltage V1a (see FIG. 5C) at the time of triangular wave superposition are enlarged as in the above example (FIGS. 4E and 4F are also compared). When comparing the pulse width modulation signal Vpwm, which is the main component of the positive voltage V1b, with the displacement detection applied signal f1 and the displacement detection detection signal Vp, it is the same as the above example (FIG. 4C, ( d) and (g)). That is, also in this case, since the bending of the displacement detection applied signal f1 and the transition of the pulse width modulation signal Vpwm are synchronized, the switching noise of the pulse width modulation signal Vpwm is a transition timing of the displacement detection detection signal Vp, that is, a rectangular shape. Limited to the rise or fall timing of the wave.

Further, the in-phase displacement detection application signals f1 to f12 do not affect the posture control, and the capacitance detection of the electrostatic support electrodes 31 to 36 and 41 to 46 is performed. As a result, the relative displacement between the gyro rotor 10 and the gyro case 20 is detected. The same applies to detection.
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 difference between the electrostatic levitation gyro apparatus of the present invention shown in FIG. 6 as an example of the frequency dividing circuit, the pulse width modulation factor conversion and the waveform is different from that of the first embodiment described above. The time-division method for switching the application destination of f12 is also extended to the switching between the application of pulses of control voltages V1 to V12 and the application of displacement detection application signals f1 to f12.
Specifically, the frequency dividing value of the frequency dividing circuit 67 is set so that the pulse period of the control voltages V1 to V12 is the same as the cycle period in which the triangular wave signal f0 appears in succession in the displacement detection application signals f1 to f12. Is set to (12 / N) (see FIG. 6). Here, the value “12” is the time division number of the displacement detection application signals f1 to f12, and N is N of the N-ary counter 64d of the pulse width modulation circuit 64b. A multiple of the time division number “12” is adopted as N so that the frequency division value becomes an integer.

  Further, in order to remove the pulse from the application timing of the displacement detection application signal during the pulse width modulation of the control voltages V1 to V12, the PWM modulation rate p calculated by the control arithmetic circuit 63 at the maximum modulation rate of 100% as described above is used. It is reduced by the reciprocal of the time division number, that is, 1/12. Specifically, the PWM modulation rate recalculated by the conversion equation [{(11 × p) / 12} + (1/12)] is sent to the latch 64c. As a result, the pulse (+ Vpwm, −Vpwm +) does not appear in the first one-twelfth period of the pulse period of the control voltages V1 to V12, and the pulse (+ Vpwm, −Vpwm +) does not appear in the control voltage V1 to V12. It appears only in the subsequent 11/12 period in the pulse period.

  Further, although not shown, the pulse width modulation circuit 64b of the control output circuit 64 that outputs the control voltage V2 from the initial value of the N-ary counter 64d of the pulse width modulation circuit 64b of the control output circuit 64 that outputs the control voltage V1. The initial value of the N-ary counter 64d of the pulse width modulation circuit 64b of the control output circuit 64 that outputs the control voltage V3 is further shifted by (N / 12). Similarly, the initial values of the N-ary counter 64d of the pulse width modulation circuit 64b of the control output circuit 64 that outputs the control voltages V3 to V12 are sequentially shifted by (N / 12), for example. , And the control voltages V1 to V12 are shifted by one clock CLKd, that is, by the time division period of the displacement detection application signals f1 to f12. Triangular wave pulse displacement detection application signal f1~f12 non expression period is also adapted to express.

  In this case, the positive voltage V1b (one of the control voltages V1) applied to the electrostatic support electrode 31b (see FIG. 6C) first causes a triangular wave of the displacement detection application signal f1 to appear and disappears. After that, a pulse of a positive pulse width modulation signal + Vpwm appears. Further, a negative voltage V1a (the other of the control voltages V1) applied to the electrostatic support electrode 31a adjacent to the electrostatic support electrode 31b (see FIG. 6D) is first applied with a displacement detection application signal. A triangular wave of f1 appears, and after it disappears, a pulse of a negative pulse width modulation signal -Vpwm appears. In the positive voltage V2b applied to the electrostatic support electrode 32b (see FIG. 6E), after the triangular wave of the displacement detection application signal f1 disappears from the control voltage V1, the triangular wave of the displacement detection application signal f2 is generated. A pulse of positive pulse width modulation signal + Vpwm appears after it has developed and disappeared. The positive voltage V3b or the like applied to the other electrostatic support electrode 33b or the like (see FIG. 6 (f)), after the triangular wave of another displacement detection application signal disappears, the displacement detection application signal f3 or the like A triangular wave appears, and after it disappears, a pulse such as a positive pulse width modulation signal + Vpwm appears.

  In this way, the displacement detection application signals f1 to f12 are applied to each application destination electrode in a time division manner, and the bending of the displacement detection application signals f1 to f12 and the transition of the control voltages V1 to V12 are also applied to the clock CLKa. In this case as well, accurate displacement detection and appropriate posture control are performed as described above. In addition, in this case, the superposition of the triangular wave (effective component) of the displacement detection application signals f1 to f12 and the pulse of the pulse width modulation signal Vpwm (effective component, main component of the control voltages V1 to V12) is eliminated. Therefore, the amplitude can be increased by changing the triangular wave of the displacement detection application signals f1 to f12 from the positive power supply voltage + Vcc to the negative power supply voltage -Vcc.

  By doing so, the displacement detection detection signal Vp having a sufficient amplitude can be obtained even when the capacitances of the plurality of electrodes 31 to 48 are large as well as small, and the accuracy of displacement detection is further improved. . Although the PWM modulation rate cannot be used up to 100%, the decrease is due to the allocation of the power supply voltage Vcc to the amplitude voltage Vf of the displacement detection application signals f1 to f12 and the maximum voltage V1m of the control voltage V1. Since it becomes unnecessary and the amplitude of the pulse width modulation signal Vpwm is completely expanded to the power supply voltage Vcc, it is compensated, so that the electrostatic attractive force for attitude control is substantially maintained. Depending on the ratio of allocation, the attitude control ability is improved.

  FIG. 7 shows a modified part of the control output circuit and an example of the waveform of the electrostatic levitation gyro apparatus of the present invention, which is different from that of the third embodiment described above. In the control output circuit 64, an N-ary counter 64d and a comparator 64e is connected to a ROM 64f for signal waveform conversion (see FIG. 7A), and the control output circuit 64 uses positive and negative power supply voltages + Vcc and -Vcc (see FIG. 2A). (Refer to FIG. 5 (a)). Since the difference of the latter has been described above, the difference of the former will be described in detail below.

  The introduction of the ROM 64f is performed only for the control output circuit 64 without recalculating the PWM modulation rate by the control arithmetic circuit 63 without removing the pulse from the application timing of the displacement detection application signal in the pulse width modulation of the control voltages V1 to V12. Specifically, when the output value of the N-ary counter 64d is less than (N / 12), the conversion value is set to “0”, and the output value of the N-ary counter 64d is set to (N / 12) ˜ In the case of N, linear conversion is performed so that the conversion value becomes a value of “0” to N.

  In this case, in the positive voltage V1b applied to the electrostatic support electrode 31b (see FIG. 7B), first, a triangular wave of the displacement detection application signal f1 appears, and after it disappears, the positive pulse width modulation is performed. A pulse of signal + Vpwm appears. In addition, in the negative voltage V1a applied to the electrostatic support electrode 31a adjacent to the electrostatic support electrode 31b (see FIG. 7C), only the triangular wave of the displacement detection application signal f1 appears, Even if it disappears, the pulse of the negative pulse width modulation signal −Vpwm does not appear. In the positive voltage V2b applied to the electrostatic support electrode 32b (see FIG. 7D), after the triangular wave of the displacement detection application signal f1 disappears from the control voltage V1, the triangular wave of the displacement detection application signal f2 is generated. A pulse of positive pulse width modulation signal + Vpwm appears after it has developed and disappeared. The positive voltage V3b and the like applied to the other electrostatic support electrode 33b and the like (see FIG. 7 (e)), after the triangular wave of another displacement detection application signal disappears, the displacement detection application signal f3 and the like A triangular wave appears, and after it disappears, a pulse with a positive pulse width modulation signal + Vpwm appears. Although illustration is omitted, the negative voltage V2a and the like, like the negative voltage V1a, only the triangular wave of the displacement detection application signals f2 to f12 appears, and even if it disappears, the pulse of the negative pulse width modulation signal −Vpwm appears do not do.

  Thus, also in this case, the displacement detection application signals f1 to f12 are applied to the respective application destination electrodes in a time division manner, and the bending of the displacement detection application signals f1 to f12 is also a transition of the control voltages V1 to V12. Since this is also synchronized with the clock CLKa, accurate displacement detection and appropriate attitude control are performed as described above. Also in this case, the superposition of the triangular wave (effective component) of the displacement detection application signals f1 to f12 and the pulse of the pulse width modulation signal Vpwm (effective component, main component of the control voltages V1 to V12) is eliminated. In this case, since the negative power supply voltage -Vcc is not used, the amplitude of the triangular wave of the displacement detection application signals f1 to f12 can be expanded from 0 V (ground voltage, reference voltage) to the positive power supply voltage + Vcc. (See FIGS. 7B to 7E).

  Thus, also in this case, the displacement detection detection signal Vp having a sufficient amplitude can be obtained, and the accuracy of displacement detection is improved. As described above, compensation for lowering the PWM modulation rate from 100% and attitude control can be performed even when a control voltage is applied to only one of the adjacent control electrode pairs.

[Others]
In each of the above-described embodiments, the rotor control circuit 52 and its control output circuit 54 remain the same as before, but the same improvements as the control arithmetic circuit 63 and its control output circuit 64 may be applied thereto.
The input means and the distribution means in the A / D conversion circuit 63a and the DSP 63b may be a part of the control arithmetic circuit 63 as described above, but are not part of the control arithmetic circuit but a part of the signal detection circuit. Even if the interface part belongs to both, there is no inconvenience. The DSP 63b of the control arithmetic circuit 63 may be provided separately from the rotor control circuit 52 as described above. However, the control arithmetic circuit 63 and the rotor control circuit 52 may be combined into a DSP in which both programs are installed. . Instead of a DSP or a microprocessor, or in combination with it, a wired logic may be used.

1 shows the structure of an electronic circuit unit of an electrostatic levitation gyro apparatus according to Example 1 of the present invention, where (a) is an overall circuit diagram including a control circuit and a signal detection circuit, and (b) is a detailed connection of a control output circuit. FIG. 4C shows a displacement detection application signal generation circuit, and FIG. 4D shows a frequency division circuit that generates a time-division clock. (A) is a detailed view of the control output circuit, and (b) is a signal input circuit. (A) to (g) are all signal waveform examples. (A) to (h) are all signal waveform examples. Example 2 of the present invention shows the structure of an electronic circuit part of an electrostatic levitation gyro apparatus, (a) is a detailed view of a displacement detection application signal generation circuit and a control output circuit, and (b) and (c) are It is an example of a signal waveform. Example 3 of the present invention shows the structure of an electronic circuit unit of an electrostatic levitation gyro device, (a) is a frequency dividing circuit that generates a time-division clock, (b) is a pulse width modulation rate conversion example, (C) to (f) are all waveform examples. Example 4 of the present invention shows the structure of an electronic circuit part of an electrostatic levitation gyro apparatus, (a) is a detailed view of a modified part of a control output circuit, and (c) to (e) are waveform examples. is there. 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 the electronic circuit part of a conventional electrostatic levitation gyro, (a) is an overall circuit diagram in which a signal detection circuit is added to a control circuit and the like, (b) is a detailed connection diagram of a control output circuit, and (c) is one. Part of the signal input circuit. It is explanatory drawing of the solution subject of this invention, (a) is a signal waveform example, (b) and (c) are voltage distribution examples, (d) is a detailed view of a conventional control output circuit, (e) is a horizontal axis (F) is a detailed diagram of the control output circuit with pulse width modulation, (g) is the horizontal axis and the vertical axis is the electrostatic capacity on the vertical axis. It is a characteristic graph which took attraction.

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)
63 Control arithmetic circuit (control circuit, constraint control system)
63a A / D conversion circuit (signal input circuit, signal detection circuit + control arithmetic circuit)
63b DSP (digital signal processor, control arithmetic circuit, constraint control system)
64 Control output circuit (PWM, control circuit)
64a Output stage circuit (switch circuit)
64b Pulse width modulation circuit 64c Latch (clock synchronous PWM modulation rate holder)
64d N-ary counter (clock synchronous sawtooth generator)
64e comparator (comparator, switch control signal generator)
65 Applied signal generation circuit (applied signal supply circuit, signal detection circuit, displacement detection system)
66 Selection circuit (overlapping destination switching circuit, time division circuit, applied signal supply circuit)
67 Frequency divider (Time division clock generation circuit, signal supply circuit, displacement detection system)
75 Application signal generation circuit (application signal supply circuit, signal detection circuit, displacement detection system)

Claims (2)

  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 for generating and applying control voltages respectively, and an application for applying a displacement detection application signal for detecting a relative displacement between the gyro rotor and the gyro case to the plurality of electrodes by superimposing the control voltage on the control voltage A signal component related to the displacement detection applied signal is detected from a signal supply circuit and a displacement detection electrode to which the control voltage is not applied among the plurality of electrodes, and a displacement detection detection signal is generated and sent to the control circuit In the electrostatic levitation gyro apparatus including the detection signal generation circuit that performs the detection, the applied signal supply circuit outputs a triangular wave voltage signal to the displacement detection mark. When the signal is superimposed on the control voltage, the superimposition destination is switched in a time division manner, and the control circuit performs pulse width modulation when generating the control voltage, and the pulse end is displaced when the pulse width modulation is performed. An electrostatic levitation type gyro apparatus that is synchronized with a bending point of a detection application signal.   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. A control circuit for generating and applying a control voltage for each, and an application signal supply circuit for applying a displacement detection application signal for detecting a relative displacement between the gyro rotor and the gyro case to the electrostatic support electrode; Detecting a signal component related to the displacement detection application signal from a displacement detection electrode to which the control voltage is not applied among the plurality of electrodes, generating a detection signal for displacement detection, and sending the detection signal to the control circuit In the electrostatic levitation gyro apparatus provided with a circuit, the applied signal supply circuit uses a triangular wave voltage signal as the applied signal for displacement detection and When applying to the electrostatic support electrode, the application destination is switched in a time-sharing manner, and the control circuit performs pulse width modulation when generating the control voltage, and applies a pulse for the displacement detection when the pulse width modulation is performed. An electrostatic levitation gyro apparatus characterized in that it removes the signal application timing and synchronizes the pulse end with the bending point of the displacement detection application signal.

Images