JP2011141210A - Method of adjusting angular velocity detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of adjusting an angular velocity detection device capable of compensating a characteristic difference of a weight in a mode uninfluenced by magnitude of a disturbance. <P>SOLUTION: The method of adjusting the angular velocity detection device for detecting angular velocity based on vibration in a vertical direction to a driving direction of two weights driven in mutually reverse phases includes: a driving step for driving the two weights in reverse phases mutually; an operation step for applying a carrier signal for amplitude modulation to detection electrodes of the two weights during driving; an excitation step for applying the same acceleration so that the two weights are vibrated in the same phase mutually in the vertical direction to the driving direction during the operation step; a signal extraction step for extracting a signal showing a vibration component in the vertical direction to the driving direction, from an electric signal acquired from the two weights during the excitation step; and an amplitude adjusting step for adjusting an amplitude of the carrier signal for amplitude modulation so that each amplitude of signals related to the two weights acquired in the signal extraction step becomes the same. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an adjustment method for an angular velocity detection device that includes two weights driven in opposite phases and detects angular velocity based on vibrations of the two weights in a direction perpendicular to the driving direction.

  Conventionally, an angular velocity sensor having a weight supported on a substrate in a displaceable manner is mounted, and a displacement amount acting on the weight when an angular velocity around a predetermined axis is generated is output from the angular velocity sensor, and a predetermined amount is determined based on the displacement amount. An angular velocity detection device that detects an angular velocity around an axis is known (for example, see Patent Document 1). In this angular velocity detection device, two weights are provided symmetrically, and these two weights are excited and oscillated in a reverse phase in a predetermined first direction, and the first direction is caused by the Coriolis force according to the angular velocity. Displacement vibration is performed in a reverse phase in a predetermined second direction orthogonal to each other. Then, a difference in displacement amount between the two weights in the second direction is detected, and an angular velocity around a predetermined axis orthogonal to both the first direction and the second direction is detected based on the displacement difference.

  As described above, in the mechanical quantity detection device described above, the angular velocity is detected based on the displacement difference between the two weights that displace and vibrate in opposite phases when the angular velocity is generated. In such a configuration, when two weights displace and vibrate in phase with each other due to disturbance vibrations or the like, there should be almost no displacement difference between the two weights. For this reason, the influence of disturbance on the angular velocity detection is eliminated, and erroneous detection of the angular velocity can be suppressed as much as possible.

  However, due to variations in processing of sensor elements of the angular velocity sensor, a difference in mass, spring characteristics, or the like may occur between the two weights described above. When such a situation occurs, a displacement difference appears when the two weights are displaced in phase due to a disturbance or the like. As a result, the configuration such as the above-described mechanical quantity detection device causes erroneous detection of angular velocity. There is a fear.

  As one approach method for preventing such erroneous detection of angular velocity, an approach method disclosed in Patent Document 2 is known. This Patent Document 2 includes two weights that are displaced in opposite phases when a predetermined mechanical quantity acts, and outputs a signal corresponding to a displacement difference between the two weights as a signal corresponding to the predetermined dynamic quantity. An angular velocity detection device that calculates the sum of the time differential values or the sum of the time differential values of the in-phase displacement component in the detection direction of the two weights, based on the calculated value by the calculation means, An angular velocity detection device is disclosed that includes a damping control unit that feedback-drives the two weights in the in-phase direction of the detection direction.

Japanese Patent No. 351004 JP 2009-47649 A

  However, in the method disclosed in Patent Document 2 described above, when a large disturbance that cannot be attenuated by the damping control means occurs, vibration due to the disturbance may be erroneously detected as an angular velocity.

  Therefore, an object of the present invention is to provide an adjustment method of an angular velocity detection device that can compensate for a characteristic difference of a weight in a manner that is not affected by the magnitude of disturbance.

In order to achieve the above object, according to one aspect of the present invention, two weights driven in opposite phases are provided, and an angular velocity is detected based on vibrations of the two weights in a direction perpendicular to the driving direction. A method for adjusting an angular velocity detection device, comprising:
A driving step for driving the two weights in mutually opposite phases;
An operation step of applying a carrier signal for amplitude modulation to each of the detection electrodes of the two weights during the driving step;
An excitation step for applying the same acceleration to the two weights so that the two weights vibrate in phase with each other in a direction perpendicular to the driving direction during the operation step;
A signal extraction step of extracting a signal representing a vibration component in a direction perpendicular to the driving direction from each electric signal obtained from two weights during the vibration step;
An adjustment method of the angular velocity detection device, comprising: an amplitude adjustment step of adjusting the amplitude of the carrier signal for amplitude modulation so that the amplitudes of the signals related to the two weights obtained in the signal extraction step are the same. Provided.

  ADVANTAGE OF THE INVENTION According to this invention, the adjustment method of the angular velocity detection apparatus etc. which can compensate the characteristic difference of a weight in the aspect which is not influenced by the magnitude of a disturbance are obtained.

It is sectional drawing which shows the principal part cross section of an example of the electronic component mounting package 10 incorporating the angular velocity detection apparatus 1 by one Example of this invention. FIG. 2 is a top view schematically showing a main part of a sensor chip 60 in the electronic component mounting package 10 of FIG. 1. It is a figure which shows the model of a yaw rate detection principle. It is a figure which shows the characteristic of the vibrator | oscillator (weight) of a yaw rate sensor. It is explanatory drawing of the yaw rate detection principle of the yaw rate detection part 70 of a tuning fork structure. FIG. 6A is a diagram illustrating various waveforms when two weights vibrate symmetrically, and FIG. 6B is a diagram illustrating various waveforms when two weights vibrate in phase. FIG. 6 is a diagram showing various waveforms when two weights vibrate in phase when there is a characteristic difference between two weights 74a and 74b. It is a block diagram which shows the principal part relevant to the adjustment function in the angular velocity detection apparatus 1 of a present Example. It is a figure which shows the hardware constitutions of the adjustment apparatus 100 used with the adjustment method of the angular velocity detection apparatus 1 of a present Example. It is a flowchart which shows the flow of the adjustment method of the angular velocity detection apparatus 1 of a present Example. It is explanatory drawing of an amplitude adjustment process. It is a block diagram which shows the principal part relevant to the adjustment function in the angular velocity detection apparatus 1 by other Examples.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a cross section of a main part of an example of an electronic component mounting package 10 incorporating an angular velocity detection device 1 according to an embodiment of the present invention. FIG. 2 is a top view schematically showing the main part of the sensor chip (sensor substrate) 60 of this embodiment.

  The electronic component mounting package 10 includes a package body 17. The package body 17 defines an internal space (cavity) 17a by a bottom portion and side walls standing from the bottom portion. Various electronic components (a sensor chip 60 and a control IC chip 40 described later) of the angular velocity detection device 1 are accommodated in the internal space 17a. The upper side of the internal space 17 a is open and is covered with the lid member 16. The package body 17 may be made of any material such as a ceramic material, or may be made of a resin material (for example, epoxy resin).

  The package body 17 includes a plurality of leads 14. The lead 14 is made of a conductive material. Each electrode of the control IC chip 40 and the lead 14 are electrically connected by wire bonding of a wire 32.

  The lid member 16 is made of a conductive material (typically a metal material). Since the lid member 16 performs a shielding function, the lid member 16 may be connected to a ground potential by a ground structure (not shown).

  The angular velocity detection device 1 mainly includes a control IC chip 40, a cap substrate 50, and a sensor chip 60.

  The control IC chip 40 includes an integrated circuit (IC) that is electrically connected to a yaw rate detection unit 70 (described later) of the sensor chip 60 and has a function of processing a signal from the yaw rate detection unit 70 of the sensor chip 60. . For example, in a vehicle mounted state, the control IC chip 40 is connected to an external control device (not shown) via the lead 14 by the wire 32. The main part of the control IC chip 40 will be described later with reference to FIG.

  The cap substrate 50 is provided so as to cover the sensor chip 60 from below, and seals and protects movable parts such as the yaw rate detection part 70 of the sensor chip 60. Further, the cap substrate 50 may be electrically protected from the yaw rate detection unit 70 of the sensor chip 60 by being connected to a constant potential such as ground. In other words, the cap substrate 50 may have an electrical shielding function and guarantee a stable operation of the yaw rate detection unit 70. Note that the cap substrate 50 may be omitted.

  The sensor chip 60 includes a substrate on which a later-described yaw rate detector 70 is formed on one side. In the illustrated example, the sensor chip 60 is disposed on the cap substrate 50 so that the installation side of the yaw rate detection unit 70 is on the cap substrate 50 side. The sensor chip 60 may be arranged so that the installation side of the yaw rate detection unit 70 is on the upper side. In this case, the cap substrate 50 may be provided so as to cover the upper side of the sensor chip 60. In addition, the sensor chip 60 and the control IC chip 40 do not necessarily have a laminated structure, and may be arranged side by side.

  The sensor chip 60 may function as a yaw rate sensor mounted on a vehicle, for example. In this case, the sensor chip 60 outputs an acceleration sensor that outputs a signal corresponding to the acceleration in the vehicle body longitudinal direction or the vehicle width direction generated in the mounted vehicle, and a yaw rate that outputs a signal corresponding to the angular velocity generated around the center of gravity axis of the vehicle. You may comprise a sensor integrally (refer FIG. 2). In this case, the electronic component mounting package 1 is embodied as a vehicle control sensor unit in which the sensor chip 60 is integrated. In this case, the electronic component mounting package 1 is provided in the vicinity of the center of gravity of the vehicle (floor tunnel or the like) with the sensor chip 60 or the like mounted therein, and the sensor chip 60 includes the yaw rate and acceleration generated at the mounting position. Is detected. The detected yaw rate and acceleration may be used, for example, for vehicle travel control that prevents side slipping and stabilizes the behavior of the vehicle.

  The sensor chip 60 is typically manufactured by a micromachine technique using an SOI (Silicon on Insulator) wafer. In this case, each element of the sensor chip 60 is configured by MEMS (Micro Electro Mechanical Systems).

  The sensor chip 60 generally includes a yaw rate detector 70 having a tuning fork structure in which left and right weights 74a and 74b are coupled by a link spring 78 as shown in FIG. The weights 74a and 74b are arranged at symmetrical positions in the X-axis direction in a state where they are lifted from the sensor chip substrate surface. The weights 74a and 74b are connected to the drive frame 72 via a detection spring 77 that can vibrate in the Y-axis direction. The drive frame 72 is connected to a fixed portion 75 (portion fixed to the sensor chip substrate) via a drive spring 71 that can vibrate in the X-axis direction. The structure of the yaw rate detector 70 of the sensor chip 60 may be arbitrary as long as it is a tuning fork structure in which the left and right weights (vibrators) are coupled by link springs as described above. For example, details of the yaw rate detection unit 70 may employ a structure described in JP 2006-242730 A (however, the damping unit may be omitted).

  3 and 4 are explanatory diagrams of the yaw rate detection principle in the yaw rate detection unit 70, and FIG. 3 is a diagram showing a model of the yaw rate detection principle and the characteristics of the weight of the yaw rate sensor.

  If angular velocity is applied in a state in which drive vibration (X-axis direction) with a constant amplitude is applied to the weight, Coriolis force acts in the direction (Y-axis direction) perpendicular to the drive vibration and the angular velocity rotation axis (Z-axis), and the detection direction ( Detection vibration is excited in the Y-axis direction). An angular velocity is detected based on the amplitude of the detected vibration. Generally, as shown in FIG. 4, the resonance frequency of the drive vibration and the detection vibration of the weight is separated by a certain amount. The drive vibration is driven at the resonance frequency. Since the detected vibration is synchronized with the drive frequency, the detection is performed at a frequency (detuning frequency) slightly away from the resonance peak of the detected vibration. The higher the resonance peak of detection (higher the Q value) and the lower the detuning frequency, the higher the sensor element sensitivity.

  FIG. 5 is an explanatory diagram of the yaw rate detection principle of the yaw rate detection unit 70 having a tuning fork structure, and FIG. 6 (A) is a diagram showing various waveforms when the two weights 74a and 74b vibrate symmetrically. (B) is a diagram showing various waveforms when two weights 74a and 74b vibrate in phase. 6A and 6B, in order from the top, the waveform of the vibration displacement A1 of the first weight 74a, the waveform of the vibration displacement A2 of the second weight 74b, and the waveform of the angular velocity signal (A1-A2). , And the waveform of the acceleration signal (A1 + A2).

  In the tuning fork structure, since the two weights 74a and 74b are symmetric vibrations, the Coriolis force also acts in the symmetric direction (see FIG. 6A). On the other hand, as shown in FIG. 6B, vehicle vibration (disturbance vibration) works in the same direction with respect to the two weights (because they are in phase), and therefore, shown in FIGS. 6A and 6B. Thus, Coriolis force and vehicle vibration can be distinguished.

  However, even in the yaw rate detection unit 70 having such a tuning fork structure, if there is a characteristic difference between the two weights 74a and 74b, a difference occurs in the in-phase vibration amplitude due to disturbance vibration, as shown in FIG. This difference generates an angular velocity signal component. That is, as shown in FIG. 6B and FIG. 7 in contrast, if there is no characteristic difference between the two weights 74a and 74b, as shown in FIG. Although there is no difference in the vibration amplitude and no component of the angular velocity signal is generated, if there is a characteristic difference between the two weights 74a and 74b, a difference occurs in the in-phase vibration amplitude due to disturbance vibration, as shown in FIG. An angular velocity signal component is generated. The characteristic difference between the two weights 74a and 74b is caused by a difference in mass or a characteristic difference between springs connected to the two weights 74a and 74b.

  Therefore, in this embodiment, it is possible to eliminate such an error factor due to the characteristic difference between the weights 74a and 74b by realizing the adjustment method and configuration described in detail below.

  FIG. 8 is a configuration diagram illustrating a main part related to the adjustment function in the angular velocity detection device 1 of the present embodiment.

  The control IC chip 40 includes an angular velocity detection circuit 42 connected to the weights 74a and 74b of the yaw rate detection unit 70 via the charge amplifier 41, and a carrier generation circuit connected to the detection electrodes (capacitors) of the weights 74a and 74b. 46.

  The charge amplifier 41 converts charges generated in the weights 74a and 74b into voltages (electric signals).

  The angular velocity detection circuit 42 detects vibration components in the detection direction (Y direction in this example) from the electric signals obtained from the weights 74a and 74b via the charge amplifier 41 (displacement signals A1 and A2 shown in FIG. 6 and the like). And an angular velocity signal is generated by taking the difference between them.

  The carrier generation circuit 46 generates a carrier signal (carrier wave) for AM modulation with vibrations (signal waves) of the weights 74a and 74b. The carrier generation circuit 46 applies carrier signals having opposite phases to the weights 74a and 74b. The carrier generation circuit 46 applies inverted carrier signals to the detection electrodes on both sides of each of the weights 74a and 74b. As shown in FIG. 8, the carrier generation circuit 46 is configured to perform voltage level shift of the carrier signal by dividing the voltage from the constant voltage source. Here, in the present embodiment, the carrier generation circuit 46 includes a variable resistor 48 that changes (adjusts) the amplitude of each carrier signal applied to each of the weights 74a and 74b. The amplitude adjusting means may be other than the variable resistor 48 and is arbitrary as long as the amplitude of each carrier signal is changed with respect to each other. In the example shown in FIG. 8, the carrier generation circuit 46 is configured to divide the voltage independently from a common constant voltage source and set the amplitude (level) of the carrier signal for each of the weights 74a and 74b. By using the variable resistor 48 for this voltage division, the amplitude of the carrier signal with respect to the weight 74a is made variable. The example shown in FIG. 8 is a configuration in which the amplitude of the carrier signal for the weight 74a is varied and the amplitude of the carrier signal for the weight 74a is adjusted with respect to the amplitude (fixed) of the carrier signal for the weight 74b. The reverse may be possible. That is, the amplitude of the carrier signal for the weight 74b may be similarly varied, and the amplitude of the carrier signal for the weight 74b may be adjusted with respect to the amplitude (fixed) of the carrier signal for the weight 74a.

  FIG. 9 is a diagram illustrating a hardware configuration of the adjusting device 100 used in the adjusting method of the angular velocity detecting device 1 according to the present embodiment.

  The adjustment device 100 is installed, for example, in the manufacturer of the angular velocity detection device 1 and performs the adjustment described later before the angular velocity detection device 1 is shipped. Alternatively, the adjustment device 100 is installed, for example, at a supplier manufacturer (for example, a vehicle manufacturer) of the angular velocity detection device 1 and performs the adjustment described later before the angular velocity detection device 1 is mounted on a product (for example, a vehicle).

  The adjustment device 100 includes a controller 102, a vibration exciter 104, a power source 106, a signal generator 108, and a measuring device 110. The functions of the signal generator 108 and the measuring device 110 may be built in the controller 102. In addition, some functions of the controller 102 (for example, an instruction / adjustment of an excitation frequency for the shaker 104 described later) may be realized by a manual operation by an operator.

  The vibrator 104 has a function of adding vibration to the angular velocity detection device 1 (the electronic component mounting package 10 in a finished product state). The vibration direction added by the shaker 104 corresponds to the detection direction of the yaw rate detection unit 70 of the angular velocity detection device 1 (in this example, the Y direction in FIG. 2). However, the vibration direction added by the shaker 104 only needs to include a component in the detection direction of the yaw rate detection unit 70. The vibration exciter 104 can adjust the vibration frequency. This adjustment is performed according to an instruction from the controller 102. The vibration by the vibrator 104 is effective for the electronic component mounting package 10 including the angular velocity detection device 1, but the angular velocity detection device in a state before being assembled as the electronic component mounting package 10. It may be performed for one single item.

  The power supply 106 has a function of supplying a power supply voltage to the angular velocity detection device 1.

  The signal generator 108 transmits various instruction signals to the control IC chip 40 of the angular velocity detection device 1. The various instruction signals include a signal for changing a resistance value of a variable resistor 48 described later, and a signal for instructing various writing to the memory in the control IC chip 40.

  The measuring device 110 measures the self-excited frequency (the driving frequency of each of the weights 74 a and 74 b) of the angular velocity detection device 1 and outputs the measurement result to the controller 102. Further, the measuring instrument 110 measures the angular velocity from the angular velocity signal (angular velocity output in FIG. 8) output from the angular velocity detection device 1 and outputs the measurement result to the controller 102. Note that the function of the measuring instrument 110 may be set on the control IC chip 40 side of the angular velocity detection device 1.

  FIG. 10 is a flowchart showing a flow of an adjustment method for the angular velocity detection device 1 of the present embodiment.

  In step 1000, the controller 102 supplies a power supply voltage from the power supply 106 to the angular velocity detection device 1 to be adjusted. In response to this, the angular velocity detection device 1 starts operating. That is, the angular velocity detection device 1 enters a normal operation state (for example, when mounted on a vehicle, the angular velocity detection device 1 is turned on when the ignition switch is turned on and is equivalent to a state in which the angular velocity can be detected). In this state, the control IC chip 40 drives the two weights 74a and 74b in the driving direction (in this example, the X direction in FIG. 2) in the same phase, and the carrier generation circuit 46 sends the carrier signal to the weights 74a and 74b. Applied to each detection electrode. At this time, since the amplitude of the carrier signal applied to each detection electrode of the weights 74a and 74b is before adjustment, it may be at an arbitrary level (that is, the resistance value of the variable resistor 48 may be arbitrary). . Typically, the amplitudes of carrier signals applied to the detection electrodes of the weights 74a and 74b are initially set to equal amplitude values.

  In step 1010, the controller 102 measures the self-excited frequencies of the weights 74 a and 74 b using the measuring instrument 110. The self-excited frequencies of the weights 74a and 74b correspond to the drive frequency when the control IC chip 40 drives the two weights 74a and 74b in the drive direction. This drive frequency corresponds to the resonance frequency in the drive direction of the weights 74a and 74b. The measuring instrument 110 may receive information representing the self-excited frequency from the control IC chip 40.

  In Step 1020, the controller 102 vibrates the weights 74a and 74b with the vibration exciter 104 at the self-excited frequency (the self-excited frequency based on the measurement result obtained in Step 1010) in the detection direction. Here, the reason for exciting at the self-excited frequency is that disturbance vibration at the self-excited frequency has the greatest influence on angular velocity detection (see FIG. 4).

  In step 1030, the controller 102 determines whether or not the angular velocity indicated by the angular velocity signal output from the angular velocity detection device 1 is zero based on the measurement result from the measuring instrument 110. The zero here does not need to be completely zero, and may include an allowable level of error. For example, the variable resistor 48 may cause a certain amount of error depending on the minimum change width (resolution) of the resistance value. If the angular velocity is zero, it is determined that the adjustment has been successfully performed or no adjustment is necessary, and the process proceeds to step 1050. On the other hand, if the angular velocity indicated by the angular velocity signal output from the angular velocity detecting device 1 is not zero, it is determined that adjustment is necessary, and the process proceeds to step 1040.

  In step 1040, the controller 102 performs amplitude adjustment processing of the carrier signal generated by the carrier generation circuit 46. That is, the controller 102 changes the resistance value of the variable resistor 48 via the signal generator 108 so that the angular velocity indicated by the angular velocity signal output from the angular velocity detection device 1 becomes zero.

Here, the amplitude adjustment processing in step 1040 will be described with reference to FIG. FIG. 11 shows waveforms of carrier signals (amplitudes are Vm1 and Vm2) applied to the upper and lower detection electrodes of the weights 74a and 74b, respectively. In the example shown in FIG. 11, the capacitance of the detection electrode of the weight 74a is C1, and the capacitance of the detection electrode of the weight 74b is C2. When the vibration of step 1020 (corresponding to disturbance) is applied, the output Vout of the charge amplifier 41 can be expressed as follows.
Vout = 2 × (ΔC1 × Vm1−ΔC2 × Vm2) / Cf Equation (1)
Here, ΔC1 and ΔC2 represent the amount of change in capacitance due to the vibration component applied in step 1020. The difference between ΔC1 and ΔC2 reflects the characteristic difference between the weight 74a and the weight 74b. Cf represents the capacitance of the feedback capacitor between the output terminal and the inverting input terminal of the charge amplifier 41 as shown in FIG.

  In Formula (1), when Vm1 = Vm2, if there is a characteristic difference between the weight 74a and the weight 74b, Vout is not zero, and the angular velocity indicated by the angular velocity signal does not become zero. On the other hand, if Vm1 (the amplitude of the carrier signal of the weight 74a) is adjusted so that the output Vout of the charge amplifier 41 becomes zero even if there is a characteristic difference between the weight 74a and the weight 74b, the weight 74a and the weight 74b. The characteristic difference between the two can be compensated. That is, in this case, even if there is a characteristic difference between the weight 74a and the weight 74b, the angular velocity indicated by the angular velocity signal when the disturbance occurs becomes zero, and the angular velocity output due to the disturbance can be zero.

  Therefore, in step 1040, the controller 102 adjusts the amplitude Vm1 of the carrier signal of the weight 74a so that the output Vout of the charge amplifier 41 becomes zero. The adjustment of the carrier signal amplitude Vm1 of the weight 74a can be realized by changing the resistance value of the variable resistor 48 as described above. For example, when Vout> zero, the controller 102 increases the resistance value of the variable resistor 48 so that the output Vout of the charge amplifier 41 becomes zero. On the other hand, when Vout <zero, the controller 102 decreases the resistance value of the variable resistor 48 so that the output Vout of the charge amplifier 41 becomes zero.

  In this manner, the controller 102 performs the carrier signal amplitude adjustment process in step 1040 until an affirmative determination is obtained in step 1030 (that is, until the angular velocity indicated by the angular velocity signal output from the angular velocity detector 1 becomes zero). Do.

  In step 1050, the controller 102 writes the adjustment value (the adjusted resistance value of the variable resistor 48) in the control IC chip 40 of the angular velocity detection device 1 via the signal generator 108. The control IC chip 40 generates a carrier signal by the carrier generation circuit 46 based on this adjustment value during actual operation. Therefore, during actual operation, even if there is a characteristic difference between the weight 74a and the weight 74b, the angular velocity output due to the disturbance becomes zero.

  FIG. 12 is a configuration diagram illustrating a main part related to the adjustment function in the angular velocity detection device 2 according to another embodiment. In the embodiment shown in FIG. 12, the carrier signal generated by the carrier generation circuit 46 is applied to the weights 74a and 74b. The role of the carrier signal itself is the same as in the above-described embodiment, and the carrier signal is AM-modulated by the vibrations of the weights 74a and 74b (capacitance change signal caused by the vibration in the Y direction).

  Electric signals taken out from the upper and lower detection electrodes of the weight 74a are input to the subtractor 45 through the charge amplifier 43a. Similarly, electrical signals extracted from the upper and lower detection electrodes of the weight 74b are input to the subtracter 45 through the charge amplifier 43b. The charge amplifier 43a has a variable capacitance feedback capacitor 47a. The variable-capacitance feedback capacitor 47a functions to vary the gain of the charge amplifier 43a as will be described later. The charge amplifier 43b includes a feedback capacitor 47b having a fixed capacity. The feedback capacitor 47a adjusts its capacitance, thereby adjusting the gain related to the electrical signal (capacitance change signal) output from the weight 74a (the gain of the charge amplifier 43a) to the gain related to the electrical signal output from the weight 74b ( The gain of the charge amplifier 43b is changed (adjusted). In the example shown in FIG. 12, the gain related to the electric signal output from the weight 74a is varied, and the amplitude of the detection signal (angular velocity component displacement signal) output from the weight 74a is detected from the weight 74b. Although it is the structure which adjusts with respect to the amplitude of a signal, the reverse may be sufficient. That is, by configuring the feedback capacitor 47b to have a variable capacity, the gain related to the electrical signal output from the weight 74b is varied, and the amplitude of the detection signal (angular velocity component displacement signal) output from the weight 74b is changed to the weight 74a. It is good also as adjusting with respect to the amplitude of the detection signal output from.

  The adjustment device used for adjustment in the angular velocity detection device 2 shown in FIG. 12 may be substantially the same as the adjustment device 100 shown in FIG. However, the controller 102 sends an instruction for changing the capacitance of the feedback capacitor 47a via the signal generator 108 (instead of an instruction for changing the resistance value of the variable resistor 48 in the above-described embodiment) to the angular velocity detection device. 2 to send.

  The adjustment method in the angular velocity detection device 2 shown in FIG. 12 may be substantially the same as the adjustment method shown in FIG. However, in step 1040, the controller 102 adjusts the capacity of the feedback capacitor 47a so that the angular velocity indicated by the angular velocity signal output from the angular velocity detecting device 1 becomes zero. As a result, even if there is a characteristic difference between the weight 74a and the weight 74b, the angular velocity indicated by the angular velocity signal when the disturbance occurs becomes zero, and the angular velocity output due to the disturbance can be zero.

  According to the angular velocity detectors 1 and 2 of the embodiment described above, the following excellent effects are achieved, among others.

  As described above, even if there is a characteristic difference between the weight 74a and the weight 74b (mass is a characteristic difference caused by a slight deviation in the spring constant), the characteristic difference is compensated by adjusting the amplitude of the carrier signal. The angular velocity output due to disturbance can be made zero. Thereby, even when there is a characteristic difference between the weight 74a and the weight 74b, the angular velocity detection accuracy can be increased with a simple (and low cost) configuration. In the above description, the adjustment is illustrated at the time of shipment. However, the same adjustment can be performed even after the shipment, and an opportunity for adjustment can be provided at an arbitrary timing.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

DESCRIPTION OF SYMBOLS 1, 2 Angular velocity detection apparatus 10 Electronic component mounting package 14 Lead 16 Lid member 17 Package body 17a Internal space 32 Wire 40 Control IC chip 41 Charge amplifier 42 Angular velocity detection circuit 43a, 43b Charge amplifier 45 Subtractor 46 Carrier generation circuit 47a, 47b Feedback capacitor 48 Variable resistance 50 Cap substrate 60 Sensor chip 70 Yaw rate detection unit 71 Drive spring 72 Drive frame 74a, 74b Weight 75 Fixed unit 77 Detection spring 78 Link spring 100 Adjustment device 102 Controller 104 Exciter 106 Power supply 108 Signal generator 110 Measuring instrument

Claims (8)

An adjustment method of an angular velocity detection device comprising two weights driven in opposite phases to each other, and detecting an angular velocity based on vibrations of the two weights in a direction perpendicular to the driving direction,
A driving step for driving the two weights in mutually opposite phases;
An operation step of applying a carrier signal for amplitude modulation to each of the detection electrodes of the two weights during the driving step;
An excitation step for applying the same acceleration to the two weights so that the two weights vibrate in phase with each other in a direction perpendicular to the driving direction during the operation step;
A signal extraction step of extracting a signal representing a vibration component in a direction perpendicular to the driving direction from each electric signal obtained from two weights during the vibration step;
An adjustment method of the angular velocity detection device, comprising: an amplitude adjustment step of adjusting the amplitude of the carrier signal for amplitude modulation so that the amplitudes of the signals related to the two weights obtained in the signal extraction step are the same. An adjustment method of an angular velocity detection device comprising two weights driven in opposite phases to each other, and detecting an angular velocity based on vibrations of the two weights in a direction perpendicular to the driving direction,
A driving step for driving the two weights in mutually opposite phases;
An operation step of applying a common carrier signal for amplitude modulation to the two weights during the driving step;
An excitation step for applying the same acceleration to the two weights so that the two weights vibrate in phase with each other in a direction perpendicular to the driving direction during the operation step;
A signal extraction step of extracting a signal representing a vibration component in a direction perpendicular to the drive direction from each electrical signal obtained from the respective detection electrodes of the two weights;
A gain adjustment step of adjusting the gain of each electrical signal obtained from the respective detection electrodes of the two weights so that the respective amplitudes of the signals related to the two weights obtained in the signal extraction step are the same. Adjustment method of angular velocity detection device.   The angular velocity detection device according to claim 1 or 2, wherein the vibration step causes the same acceleration to act on the two weights so that the two weights vibrate in phase with each other at the same frequency as the driving frequency in the driving step. Adjustment method. An angular velocity detecting device comprising two weights driven in opposite phases to each other, and detecting an angular velocity based on vibrations of the two weights in a direction perpendicular to the driving direction,
A carrier generation circuit for applying a carrier signal for amplitude modulation to each detection electrode of the two weights,
The carrier generation circuit comprises an angular velocity detecting device comprising amplitude adjusting means for adjusting the amplitude of the carrier signal for amplitude modulation for one weight with respect to the amplitude of the carrier signal for amplitude modulation for the other weight.   The angular velocity detection device according to claim 4, wherein the amplitude adjusting unit includes a variable resistor.   The amplitude adjusting means is 2 under the situation where the two weights vibrate in phase with each other in the direction perpendicular to the driving direction due to the same acceleration acting on the two weights in the direction perpendicular to the driving direction. The amplitude of each carrier signal is adjusted such that the amplitude of each electrical signal obtained from two weights and the amplitude of each electrical signal representing a vibration component in a direction perpendicular to the driving direction is the same. 4. An angular velocity detection device according to 4. An angular velocity detecting device comprising two weights driven in opposite phases to each other, and detecting an angular velocity based on vibrations of the two weights in a direction perpendicular to the driving direction,
An angular velocity detection circuit that generates an angular velocity signal by taking the difference between the detection signals output from the detection electrodes of the two weights;
The angular velocity detection circuit is provided with a gain adjusting means for adjusting a gain related to a detection signal of one weight with respect to a gain related to the detection signal of the other weight.   The gain adjusting means is 2 in a situation where the two weights vibrate in phase with each other in the direction perpendicular to the driving direction due to the same acceleration acting on the two weights in the direction perpendicular to the driving direction. The angular velocity detection device according to claim 7, wherein the gain is adjusted so that the amplitudes of the detection signals obtained from two weights are the same.

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