JP2008224509A - Vibration type gyro sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration type gyro sensor capable of detecting an angular velocity imparted to a vibrator and a rotation direction of the vibrator without complicating structure and a circuit of the gyro sensor. <P>SOLUTION: In this vibration type gyro sensor for determining the angular velocity imparted to the vibrator 20 based on a phase difference between the phase of a driving signal from a driving part and the phase of a detection signal from a detection part, four magnetometric sensors 22, 24, 26, 28 as detection parts are arranged mutually separately in two rows and two columns and used, and while vibrating the vibrator along a diagonal of an arrangement body of the four magnetometric sensors, a differential signal of the four magnetometric sensors is detected, and the rotation direction of the vibrator is detected based on positiveness/negativeness to a center time point between the four magnetometric sensors of a zero cross point of the differential signal on the middle point of the four magnetometric sensors. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vibration type gyro sensor that detects an angular velocity applied to a vibrator by using a Coriolis force. More specifically, the vibration type gyro sensor detects the angular velocity based on a phase difference between a drive signal and a detection signal. It relates to sensors.

  Conventionally, as a vibratory gyro sensor that detects an angular velocity applied to a vibrator using Coriolis force, the vibrator, a drive unit that applies vibration to the vibrator, and a detection unit that detects vibration of the vibrator are provided. In addition, a vibration type gyro sensor that obtains an angular velocity applied to the vibrator based on a phase difference between the phase of the drive signal of the drive unit and the phase of the detection signal of the detection unit has been proposed (see Patent Documents 1 to 3). .

  On the other hand, in the vibration type gyro sensor, when detecting the rotation direction of the vibrator, a sensor other than the detection unit for detecting the vibration of the vibrator, such as an acceleration sensor, is provided in the vibration element.

  Also, paying attention to the vibration phase in the transverse direction of the vibrator, the phase of the vibration in the transverse direction changes by 180 degrees depending on the rotation direction, so the detection direction of the vibrator can be detected by performing phase detection of the detection signal of the detection unit. Has also been proposed (see Patent Document 4).

Japanese Patent Publication No. 4-14734 Japanese Patent Laid-Open No. 10-153432 JP-A-10-206166 JP-A-5-312579

  However, the method of providing the vibration element with a sensor different from the detection unit for detecting the vibration of the vibrator in order to detect the rotation direction of the vibrator has a problem that the structure of the gyro sensor becomes complicated.

  In addition, in the method of detecting the phase of the detection signal of the detection unit in order to detect the rotation direction of the vibrator, it is necessary to provide a circuit for performing phase detection, which causes a problem that the circuit of the gyro sensor becomes complicated. It was.

  The present invention has been made in view of the above-described circumstances, and a vibration gyro capable of detecting the angular velocity applied to the vibrator and the rotation direction of the vibrator without complicating the structure and circuit of the gyro sensor. An object is to provide a sensor.

  In order to achieve the above object, the present invention includes, as a first invention, a vibrator made of a magnetic material, a drive unit that applies vibration to the vibrator, and a detection unit that detects vibration of the vibrator. A vibration type gyro sensor for obtaining an angular velocity applied to the vibrator based on a phase difference between a phase of a drive signal of the drive unit and a phase of a detection signal of the detection unit, and two magnetic sensors as the detection unit Are used while the vibrators are vibrated along the longitudinal direction of the array of the two magnetic sensors, and the differential signals of the two magnetic sensors are detected. A vibration type die that detects a rotation direction of the vibrator based on a positive / negative of a zero cross point of the differential signal in the intermediate portion of the magnetic sensor with respect to a central time point between the two magnetic sensors. To provide a Irosensa.

  In order to achieve the above object, the present invention includes, as a second invention, a vibrator made of a magnetic material, a drive unit that applies vibration to the vibrator, and a detection unit that detects vibration of the vibrator. A vibration type gyro sensor that obtains an angular velocity applied to the vibrator based on a phase difference between a phase of a drive signal of the drive unit and a phase of a detection signal of the detection unit, and includes four magnetic sensors as the detection unit Are arranged in two rows and two columns separated from each other, and the vibrators are vibrated along diagonal lines of the array of the four magnetic sensors, and the differential signals of the four magnetic sensors are detected. The rotation direction of the vibrator is detected based on the positive / negative of the zero cross point of the difference signal in the intermediate part of the four magnetic sensors with respect to the central time point between the four magnetic sensors. To provide a dynamic type gyro sensor.

  In the vibration-type gyro sensor of the first invention, in order to detect a differential signal between the two magnetic sensors while vibrating the vibrator along the longitudinal direction of the array of the two magnetic sensors, The difference signal is zero at both longitudinal ends of the array of two magnetic sensors. This is because the outputs of the two magnetic sensors are equal when the magnetic sensor is located in the middle of the two magnetic sensors, and the magnetic sensors are located at both longitudinal ends of the array of the two magnetic sensors. This is because the outputs of the two magnetic sensors are both zero. Therefore, the output waveforms of the differential signals of the two magnetic sensors are obtained when the rotation direction of the magnetic sensor shown in FIG. 1A is a right rotation and when the rotation direction of the magnetic sensor shown in FIG. 1B is a left rotation. Thus, the positive / negative of the zero cross point X of the difference signal in the intermediate part of the two magnetic sensors with respect to the central time point Y between the two magnetic sensors is reversed. That is, in FIG. 1A, the zero cross point X is located on the plus side with respect to the center time point Y, and in FIG. 1B, the zero cross point X is located on the minus side with respect to the center time point Y. Note that the central time point refers to a half of the time during which the vibrator vibrates between both longitudinal ends of the array of two magnetic sensors in the waveform diagram. Therefore, according to the first aspect of the invention, the angular velocity applied to the vibrator can be obtained based on the magnitude of the difference signal between the two magnetic sensors, and the zero cross point of the difference signal at the intermediate portion between the two magnetic sensors can be obtained. It is possible to determine the rotational direction of the vibrator based on positive / negative with respect to the central time point between the two magnetic sensors. Therefore, in the first invention, in order to detect the rotation direction of the vibrator, a sensor different from the detection unit for detecting the vibration of the vibrator is not provided in the vibration element, or a circuit for performing phase detection is not provided. Both the angular velocity applied to the vibrator and the direction of rotation of the vibrator can be detected with a simple structure and circuit.

  In the vibration-type gyro sensor according to the second aspect of the invention, in order to detect the differential signal of the four magnetic sensors while vibrating the vibrator along the diagonal line of the array of four magnetic sensors, The difference signal becomes zero at the diagonal portion of the array of two magnetic sensors. This is because the outputs of the four magnetic sensors are equal when the magnetic sensor is located in the middle of the four magnetic sensors, and when the magnetic sensor is located at the diagonal part of the array of the four magnetic sensors. This is because the outputs of the four magnetic sensors are all zero. For this reason, the output waveforms of the difference signals of the four magnetic sensors are the same as in the first invention, when the rotation direction of the magnetic sensor shown in FIG. 1A is clockwise and when the rotation direction of the magnetic sensor shown in FIG. When the rotation direction is the left rotation, the positive / negative of the zero cross point X of the difference signal in the middle part of the four magnetic sensors with respect to the central time point Y between the four magnetic sensors is reversed. Note that the central time point refers to a half of the time during which the vibrator vibrates between the diagonal portions of the array of four magnetic sensors in the waveform diagram. The central time point refers to a half of the time during which the vibrator vibrates between both longitudinal ends of the two magnetic sensor arrays in the waveform diagram. Therefore, according to the second invention, the angular velocity applied to the vibrator can be obtained based on the magnitudes of the difference signals of the four magnetic sensors, and the zero cross point of the difference signal at the intermediate portion of the four magnetic sensors can be obtained. The rotational direction of the vibrator can be obtained based on positive / negative with respect to the central time point between the four magnetic sensors. Therefore, in the second invention, in order to detect the rotation direction of the vibrator, a sensor different from the detection unit for detecting the vibration of the vibrator is not provided in the vibration element, or a circuit for performing phase detection is not provided. Both the angular velocity applied to the vibrator and the direction of rotation of the vibrator can be detected with a simple structure and circuit.

  Hereinafter, the present invention will be described in more detail. In the present invention, the material of the vibrator is not limited, and can be appropriately selected from, for example, a magnetic material, a piezoelectric material, and a constant elastic material. Further, the shape of the vibrator is not limited, and can be appropriately selected from, for example, a sound type, a beam type, a plate type, a ring type, a ball type, a linear type, and a reed relay type.

  In the present invention, as the element used for the drive unit, for example, an element that uses electromagnetic induction (transformer, coil, etc.), an element that uses the galvanomagnetic effect (magnetoresistance effect element, Hall element, magnetic transistor, etc.), Although the thing using an electrostatic force, the thing using a piezoelectric effect, etc. can be mentioned, It is not limited to these.

  In the present invention, examples of the magnetic sensor used in the detection unit include, but are not limited to, an MR element, a Hall element, a magnetic transistor, and a coil.

  In the present invention, the vibrator can be disposed inside the tubular container. In this case, as the tubular container, for example, a glass, metal (aluminum, nonmagnetic stainless steel, copper, brass, etc.), ceramic, plastic, or the like can be used.

  In the present invention, the means for detecting the angular velocity applied to the vibrator based on the phase difference between the phase of the drive signal of the drive unit and the phase of the detection signal of the detection unit is not limited. For example, the difference signal of the magnetic sensor Means for detecting the phase difference can be used by comparing the differential value with the differential value of the drive signal of the drive unit.

  In the present invention, there is no limitation on the means for detecting the rotation direction of the vibrator based on the positive / negative of the zero cross point of the difference signal in the intermediate part of the magnetic sensor with respect to the central time point between the magnetic sensors. For example, the difference of the magnetic sensor Means for determining the rotation direction based on the positive / negative of the differential value of the signal can be used.

  According to the vibration type gyro sensor of the present invention, the angular velocity applied to the vibrator and the rotation direction of the vibrator can be detected without complicating the structure and the circuit.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following examples. In any of the vibration type gyro sensors of the following embodiments, the angular velocity applied to the vibrator is detected using Coriolis force.

(First embodiment)
2A and 2B show an example of a vibration type gyro sensor according to the first invention. FIG. 2A is a schematic plan view and FIG. 2B is a schematic side view. The vibration-type gyro sensor of this example includes a vibrator 10 made of a magnetic material, a drive unit (not shown) that vibrates the vibrator 10, and two MR elements 12 and 14 having the same performance, separated from each other. And arranged detectors. The vibrator 10 is disposed so as to face the MR elements 12 and 14 while being separated from the MR elements 12 and 14. In FIG. 2A, the vibrator 10 is indicated by a chain line.

  Specifically, for example, the vibrator 10 shown in FIG. 3 can be used. In the vibrator of this example, a sound type vibrator 42 made of a magnetic material (for example, Ni, Fe, Co, etc.) is attached to the distal end portion of the linear support body 40, and a coil 44 is used as a drive element in the vicinity of the vibrator 42. Is arranged. In the vibrator of this example, the proximal end side of the linear support body 40 and the coil 44 are enclosed in a mold body 48 made of an elastomer, and the distal end side of the linear support body 40 and the vibrator 42 are in the mold body 48. It is arranged inside a tubular container 50 having a circular cross section made of glass enclosed in the inside. The coil 44 is enclosed in a mold body 48 in a state of being wound around the outer periphery of the tubular container 50. The vibrator 10 of the present example applies a vibration in the direction of the arrow in the figure to the vibrator 42 by the coil 44 so that the tip of the vibrator 42 opens and closes.

  The vibration type gyro sensor according to the present embodiment obtains the angular velocity applied to the vibrator 10 based on the phase difference between the phase of the drive signal of the drive unit and the phase of the detection signal of the detection unit, and the MR elements 12 and 14 The rotation direction of the vibrator 10 is detected based on the positive / negative of the zero cross point of the difference signal in the intermediate portion with respect to the central time point between the MR elements 12 and 14.

  In this case, in the vibration type gyro sensor of the present embodiment, the vibrator 10 is vibrated along the longitudinal direction 18 of the array 16 of the two MR elements 12 and 14, and the differential signal of the two MR elements 12 and 14 is obtained. At the same time, the angular velocity applied to the vibrator 10 is obtained based on the magnitude of the difference signal, and the two MR elements 12 and 14 at the zero crossing point of the difference signal at the intermediate portion between the two MR elements 12 and 14 are obtained. The rotation direction of the vibrator 10 is obtained based on the positive / negative with respect to the central time point (see FIG. 1). More specifically, by comparing the zero-cross point of the differential value of the detection signal of the detection unit and the differential value of the drive signal of the drive unit, the phase difference is detected and the angular velocity given to the vibrator is obtained. The rotational direction of the vibrator is determined based on whether the differential value of the detection signal of the detection unit is positive or negative.

  In the vibration type gyro sensor of the first embodiment, examples of means for detecting the angular velocity applied to the vibrator and detecting the rotation direction of the vibrator include means using a circuit shown in FIG. In FIG. 4, 60 is a basic signal, 62 is a frequency dividing circuit for converting the frequency of the basic signal 60 to ½ to generate a drive signal 64 for the vibration element, 66 is a differentiating circuit for differentiating the basic signal, 14 is an MR element, 68 and 70 are resistors, 72 is an operational amplifier (differential amplifier circuit) that outputs a differential signal of the MR elements 12 and 14, 74 is a differential circuit that differentiates the differential signal, and 76 is a basic signal. A comparison circuit (an AND circuit in this example) that outputs a comparison signal between the differential signal of the MR element and the differential signal of the differential signal of the MR elements 12 and 14 is shown. In the circuit of this example, the angular velocity applied to the vibrator and the rotation direction of the vibrator are detected based on the output signal (AND circuit signal) of the comparison circuit 76.

(Second Embodiment)
FIG. 5 shows an example of a vibration-type gyro sensor according to the second invention, wherein (a) is a schematic plan view and (b) is a schematic side view. The vibration-type gyro sensor of this example includes a vibrator 20 made of a magnetic material, a drive unit (not shown) that gives vibration to the vibrator 20, and four MR elements 22, 24, 26, and 28 having the same performance. And detection units arranged in two rows and two columns apart from each other. The MR elements 22 and 26 are sensitive to magnetism in the vertical direction in the figure, and the MR elements 24 and 28 are sensitive to magnetism in the vertical direction in the figure. The vibrator 10 is disposed so as to face the MR elements 22, 24, 26, 28 in a state of being separated from the MR elements 22, 24, 26, 28. In FIG. 3A, the vibrator 20 is indicated by a one-dot chain line. Specifically, for example, the vibrator 20 shown in FIG. 3 can be used.

  The vibration type gyro sensor according to the present embodiment obtains the angular velocity applied to the vibrator 20 based on the phase difference between the phase of the drive signal of the drive unit and the phase of the detection signal of the detection unit, and the MR elements 22, 24, The rotational direction of the vibrator is detected based on the positive / negative of the zero cross point of the differential signal at the intermediate part of 26 and 28 with respect to the central time point between the MR elements 22, 24, 26 and 28.

  In this case, in the vibration type gyro sensor of the present embodiment, the four MR elements 22, 24, 26 are vibrated along the diagonal line 32 of the array 30 of the four MR elements 22, 24, 26, 28. , 28 difference signals are detected, and the angular velocity applied to the vibrator 20 is obtained based on the magnitude of the difference signal, and the zero cross points of the difference signals at the intermediate portions of the four MR elements 22, 24, 26, 28 are obtained. The rotational direction of the vibrator 20 is obtained based on positive / negative with respect to the central time point between the four MR elements MR elements 22, 24, 26, and 28 (see FIG. 1). More specifically, by comparing the zero cross point of the differential value of the detection signal of the detection unit with the drive signal of the drive unit, the phase difference is detected to obtain the angular velocity applied to the vibrator 20, and the detection unit The rotational direction of the vibrator 20 is determined based on whether the differential value of the detection signal is positive or negative.

  In the vibration type gyro sensor according to the second embodiment, as means for detecting the angular velocity applied to the vibrator and detecting the rotation direction of the vibrator, for example, means using a circuit shown in FIG. In FIG. 6, 60 is a basic signal, 62 is a frequency dividing circuit for converting the frequency of the basic signal 60 to ½ to generate a driving signal 64 for the vibration element, 66 is a differentiating circuit for differentiating the basic signal, 22, Reference numerals 24, 26, and 28 denote MR elements, 72 denotes an operational amplifier (differential amplifier circuit) that outputs a differential signal of the MR elements 22, 24, 26, and 28, 74 denotes a differential circuit that differentiates the differential signal, and 76 denotes a basic circuit. 2 shows a comparison circuit (AND circuit in this example) that outputs a comparison signal between the differential signal of the signal and the differential signal of the differential signal of the MR elements 22, 24, 26, and 28. In the circuit of this example, the angular velocity applied to the vibrator and the rotation direction of the vibrator are detected based on the output signal (AND circuit signal) of the comparison circuit 76. An example of the differential waveform of the detection signal of the detection unit in the present embodiment is shown in FIG. The rotational direction of the vibrator can be determined by checking the positive / negative of the digital value of the detection signal in FIG.

It is a graph which shows typically the output waveform of the difference signal of a magnetic sensor. An example of the vibration-type gyro sensor which concerns on 1st invention is shown, (a) is a typical top view, (b) is a typical side view. An example of a vibrator is shown, (a) is a schematic front view, and (b) is a schematic side view. It is a circuit diagram which shows an example of the angular velocity and rotation direction detection circuit used for the vibration type gyro sensor of 1st Embodiment. An example of the vibration-type gyro sensor which concerns on 2nd invention is shown, (a) is a typical top view, (b) is a typical side view. It is a circuit diagram which shows an example of the angular velocity and rotation direction detection circuit used for the vibration type gyro sensor of 2nd Embodiment. It is a graph which shows an example of the differential waveform of the detection signal of a detection part.

Explanation of symbols

10 vibrator 12, 14 MR element 16 MR element array 18 longitudinal direction 20 vibrator 22, 24, 26, 28 MR element 30 MR element array 32 diagonal

Claims (3)

  A vibrator formed of a magnetic material; a drive unit that applies vibration to the vibrator; and a detection unit that detects vibration of the vibrator; and a phase of a drive signal of the drive unit and a detection signal of the detection unit A vibration type gyro sensor for obtaining an angular velocity applied to the vibrator based on a phase difference from a phase, wherein two magnetic sensors are arranged apart from each other as the detection unit, and the two magnetic sensors are used. While detecting the differential signal of the two magnetic sensors while vibrating the vibrator along the longitudinal direction of the sensor array, the 2 cross-points of the zero cross point of the differential signal in the intermediate part of the two magnetic sensors are detected. A vibration type gyro sensor that detects a rotation direction of the vibrator based on positive or negative with respect to a central time point between two magnetic sensors.   A vibrator formed of a magnetic material; a drive unit that applies vibration to the vibrator; and a detection unit that detects vibration of the vibrator; and a phase of a drive signal of the drive unit and a detection signal of the detection unit A vibration type gyro sensor that obtains an angular velocity applied to the vibrator based on a phase difference from a phase, wherein four magnetic sensors are separated from each other and arranged in two rows and two columns as the detection unit. , While detecting the difference signal of the four magnetic sensors while vibrating the vibrator along the diagonal line of the array of the four magnetic sensors, and the zero cross point of the difference signal in the intermediate portion of the four magnetic sensors A vibration type gyro sensor that detects a rotation direction of the vibrator based on positive / negative with respect to a central time point between the four magnetic sensors.   3. The vibration gyro sensor according to claim 1, wherein the magnetic sensor is an MR element.

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