JPH10122865A - Detecting and measuring method for rotational angular velocity and gyro for execution of the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detecting and measuring method in which an angular velocity can be measured with high accuracy by a method in which a detected angular-velocity signal which is output from a mechanical part at a gyro is computed and processed and a contained angular-velocity offset is removed. SOLUTION: An angular-velocity output from a mechanical part at a gyro body 1 is input to an offset removing and processing part 2 and an offset measuring and processing part 3. The offset removing and processing part 2 removes an angular- velocity offset from the angular-velocity output on the basis of a processed result by the offset measuring and processing part 3. A result which removes the offset is input to an integrating and processing part 4, and it is integrated and processed so as to obtain an angle output. The offset is removed, integrated and processed numerically by a CPU. At this time, a command is input in a state that a gyro is at a standstill, a normal measuring state is changed over to an angular-velocity offset measuring state, and an angle output which is integrated in a prescribed time within several minutes is measured. The difference between an angle at the start of its measurement and an angle at the finish of its measurement is divided by the prescribed time, and the angular-velocity offset is computed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting and measuring a rotational angular velocity and a gyro for implementing the method. The present invention relates to a method for detecting and measuring a rotational angular velocity for reducing and removing an angular velocity offset included in a gyro and a gyro for implementing the method.

[0002]

2. Description of the Related Art A gyro is known as a sensor for detecting and measuring a rotational angular velocity of a moving body with respect to an inertial space.
Rotational motion with respect to inertial space, that is, motion with respect to absolute space. For example, when a gyro is operated on the earth, the gyro is a combination of the rotational movement of the moving body with the gyro attached to the earth coordinates and the movement of the earth itself in the absolute space, that is, the rotation movement and the orbital movement of the earth. Is output. Such characteristics of the gyro have been known for a long time, and have been used as a method of knowing the direction of the rotation axis of the earth's rotation, that is, true north. However, since the old gyro is based on the characteristics of top music that rotates at a high speed and is extremely expensive because of the need for precision machining during manufacture and other reasons, its application fields are ships,
It has been limited to the field of devices that are rarely supported externally, such as aircraft and space vehicles.

Here, in a gyro, there is generally an angular velocity offset in the detected angular velocity. The angular velocity offset of the gyro is the angular velocity actually output when the gyro is stationary and the angular velocity output should be zero. If an angular velocity offset exists when the rotational angle of the moving body is detected and measured by a gyro, the detected angle obtained by integrating the detected angular velocity includes an angular error obtained by temporally integrating the offset value. Therefore, a gyro used for performing accurate angle detection and measurement must be a gyro having an extremely small angular velocity offset. A gyro with a very small angular velocity offset means that it is a very high performance gyro, ie generally a very expensive gyro. High-grade gyros used for autopilot of aircraft
This means that the gyro has a very small angular velocity offset. This is because the gyro itself is designed and manufactured in order to minimize the output angular velocity offset, and the measurement angle error is as high as 0.01 ° / hour. The accuracy is high, and the price is as high as several million yen. The gyro was not applicable to general industrial equipment from this point, and its application field was limited.

In recent years, optical fiber gyros, vibrating gyros, and other low-cost gyros have been developed, and the gyros have come into wide use in general industrial equipment technical fields. Intermediate gyros used for ordinary aircraft rotation angle detection, radio control of tractors and robots have a measurement angle error with an accuracy of the order of 1 ゜ / 1 hour,
The price is around several hundred thousand yen. The gyro used for car navigation has an accuracy that causes a measurement angle error of 400 ° / 1 hour. That is, in some cases, a large measurement angle error of about one time is generated in one hour. Examples of applications in the technical field of general industrial equipment include direction detection and control of unmanned vehicles, and roll angle control of trains such as pendulum trains. In the case of such an application example, it is almost intended to detect the angle of a specific one axis of the moving body with respect to the ground surface. In such an application example, there is a case where the characteristics of the gyro itself become harmful. In other words, since the gyro detects the rotational movement with respect to the inertial space, the gyro detects the rotation of the earth as described above, and the gyro outputs a constant rotational movement even when the moving body is stationary with respect to the ground surface. Becomes This detection error caused by the rotation of the earth has a maximum angle deviation of 15 ° per hour, which has a considerable effect on the measurement result. In such a case, a countermeasure may be provided by providing a dead zone below a certain level for setting the angular velocity signal to 0 with respect to the gyro output stage. However, in general, the gyro angular velocity signal has an angular velocity offset at rest. Therefore, if a dead zone of the same level is provided in the left-right direction or in the + -direction, a difference occurs in the dead level in the left-right direction or the +-direction, in other words, the detectable level by an offset, and the left-right repetition such as a pendulum motion occurs. When the rotational motion is input, there is a difference between the left and right angular velocity outputs, and a problem that the angle deviation appears in a direction having an angular velocity offset in the stage of calculating the angle by integrating them is left as a problem.

Furthermore, it is known that the angular velocity offset of a gyro generally changes with temperature. This is referred to as the gyro bias temperature drift and is known to indicate the performance grade of the gyro. If the temperature changes during normal angular velocity and angle measurement, the angular velocity offset of the gyro itself, which is the offset value to be removed, changes, which also causes an integration error, that is, an angular drift.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a detected angular velocity signal output from a mechanical portion which is a gyro body is arithmetically processed to reduce and remove an angular velocity offset included in the signal, thereby calculating a detected angular velocity signal of the gyro. It is an object of the present invention to provide a method for detecting and measuring a rotational angular velocity for performing high-accuracy angular velocity measurement as a whole gyro including a processing circuit, and a gyro for implementing the method.

[0007]

SUMMARY OF THE INVENTION A method of detecting and measuring a rotational angular velocity in which a rotational angular velocity of a moving body is detected and measured by a gyro, an offset removing process for a detected angular velocity signal output from a mechanical unit 1 of the gyro is periodically and frequently performed. Was configured. In a gyro for detecting and measuring a rotational angular velocity of a moving body, the gyro includes an offset measurement processing section 3 for inputting a detected angular velocity signal output from the mechanical section 1 of the gyro and measuring an offset. A gyro including an offset removal processing unit 2 for inputting the detected angular velocity signal to be output and inputting the offset output from the offset measurement processing unit 3 and performing an offset removal process on the detected angular velocity signal is configured.

The gyro according to the second aspect of the present invention is configured such that the gyro includes an integration processing unit for integrating the angular velocity output of the angular velocity offset removal processing unit. Claim 4: The gyro according to any one of claims 2 and 3, wherein the gyro includes a CPU for performing arithmetic processing of offset removal and angular velocity integration.

In the gyro according to any one of claims 2 to 4, the angular velocity is integrated during an offset measurement time that is a predetermined time, and the angle at the integration start time and the angle at the integration end time are integrated. A gyro is configured in which the angular difference between the angles is divided by the offset measurement time to calculate the angular velocity offset value, and the angular velocity offset value is subtracted from the measured angular velocity to remove the offset.

Claim 6: In the gyro according to any one of claims 2 to 5, the mechanical portion 1 of the gyro is any one selected from an optical fiber gyro, a vibration gyro, and a silicon gyro. A gyro was constructed. Claim 7: In the gyro according to any one of claims 2 to 6, a dead zone process in which an angular velocity output obtained as a result of the angular velocity offset removal in the offset removing section 2 is input to and a dead zone is set therein. A gyro including the unit 5 was configured.

Claim 8: In the gyro according to claim 7, a gyro for inputting the angular velocity output subjected to the dead processing by connecting the dead processing section 5 to the integration processing section 4. Claim 9: In the gyro according to any one of claims 5 to 8, a gyro having a configuration in which the offset measurement time is variable is provided. Claim 10: In the gyro according to claim 9,
A gyro in which the offset measurement time is changed by a command input from the outside or a changeover switch is configured.

Claim 11: The gyro according to any one of claims 9 and 10, wherein the gyro includes a self-diagnosis unit for setting an optimum offset measurement time.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the embodiment shown in FIG. FIG. 1 shows an example in which an optical fiber gyro is employed as the gyro. Since this is a well-known and conventional one, a special description is omitted. As the gyro, a vibration gyro and a silicon gyro can be employed in addition to the optical fiber gyro.

Reference numeral 1 denotes a mechanical part of the gyro.
The output of the gyro 1 has the dimension of angular velocity, and the angular velocity output is input to the offset removal processing unit 2 and the offset measurement processing unit 3. Offset removal processing unit 2
In, the result obtained by removing the angular velocity offset from the angular velocity output based on the processing result of the offset measurement processing unit 3 is input to the integration processing unit 4 and integrated to obtain an angle output. The offset removal processing and the integration processing are performed numerically by a CPU (not shown).

In the measurement of the angular velocity offset, in the stationary state of the gyro, the operation state of the gyro is changed from the normal angle and angular velocity measurement state to the angular velocity offset measurement state by a command input supplied from the outside or a preset sequence. Switch to the state and measure the angular output integrated over a predetermined time period of about several minutes or less. The angular velocity offset can be calculated by dividing the angle difference between the angle at the start of measurement and the angle at the end of measurement by a predetermined time. In a normal angle and angular velocity measurement state, a process of numerically subtracting the angular velocity offset value from the gyro measurement value is frequently performed by a CPU (not shown), and the previous offset measurement value is measured until a new angular velocity offset measurement is performed. Remember and use.

In the angular velocity offset measurement state, normal angle and angular velocity cannot be measured.
As described above, since the measurement of the angular velocity offset is performed in a stationary state, there is no practical problem by storing the angle immediately before the start of the offset measurement. A flowchart for measuring an angle and an angular velocity according to the present invention is as follows.

1: Gyro switch ON 2: Angular velocity offset measurement 3: Normal angle and angular velocity measurement 4: Returning to this flowchart, the gyro switch is turned ON to start up the gyro, and the angular velocity offset measurement is performed. I do. Next, a normal angle and angular velocity measurement state is entered, and a normal measurement is performed. Angular velocity offset removal is performed regularly and frequently. For example, "frequently and periodically" means that angular velocity offset removal is performed within 30 minutes, for example, and this is repeated.

According to the present invention, the gyro needs to be stationary during a few minutes while the offset measurement is being performed. That is, the moving body on which the gyro is mounted must be stationary. In the general industrial equipment technology field, unmanned vehicles, trains such as pendulum trains as moving bodies equipped with gyros,
Things such as tunnel excavators are well known. Unmanned vehicles in these moving bodies have a stop when refueling,
If it is a train, it will stop at the station, if it is a tunnel excavator, it will be at the time of earth and sand removal, pipe connection and other construction work,
At these times, be sure to stay still. If the offset measurement is performed using such a period, the present invention can be easily implemented without wasting time, and it becomes unnecessary to use a high-precision, that is, expensive gyro.

Another embodiment will be described with reference to FIG. In FIG. 2, reference numeral 1 denotes a mechanical part of the gyro as in FIG. In this embodiment, the angular velocity output resulting from the angular velocity offset removal in the offset removal processing unit 2 is input to the insensitive processing unit 5. Dead processing section 5
In step (1), the angular velocity output subjected to the insensitive processing is input to the integration processing unit 4 for integration processing to obtain an angle output. Dead processing section 5
Sets a dead zone in which the angular velocity signal from which the angular velocity offset has been removed is subjected to dead processing for setting an angular velocity signal of a certain level or less to zero. The angular velocity signal that has been subjected to the insensitive processing is input to the integration processing unit 4, where the integration processing is performed to obtain an angle output. Here, the offset removal processing, the insensitive processing, and the integration processing are numerically performed by a CPU (not shown).

As described above, the angular velocity signal resulting from the frequent angular velocity offset removal is set to a dead zone where the angular velocity signal is set to zero after balancing the detected angular velocities in the left and right directions. Even if such rotational movements are repeated in the left and right direction, there is no problem that an angular deviation appears in a direction with an angular velocity offset, and the angular integration error described above occurs when the detected angular velocities in the left and right directions are balanced. Disappears. The dead zone can be numerically given by the CPU as described above, but can also be processed as an electric circuit by connecting a dead processing circuit to the output of the gyro 1. Any of the blinding processes can employ a conventionally used technique.

Another embodiment will be described. Incidentally, the angular velocity offset of the gyro has a temperature characteristic, and as described above, a temperature drift occurs. This angular velocity offset temperature drift can reduce its effect by frequently performing earlier offset measurements. That is, even if the angular velocity offset itself changes due to the influence of temperature or other external conditions, frequent offset measurement is performed, and the offset value to be removed is updated to the latest one, so that the angle which is an integration error is obtained. This is because the drift can be minimized. However, noise exists in the angular velocity signal detected by the gyro. In the optical fiber gyro of the gyro, the detection limit of the angular velocity of the gyro is determined by the shot noise in the light receiver. This shot noise determines the limit of the final offset removal when performing the offset removal. That is, when the offset amount is calculated by taking the angle difference within a predetermined time, the angle measurement result has an error corresponding to the width of the noise. Need to be longer.

Accordingly, an offset measurement time setting device for appropriately setting the offset measurement time is provided. This setting device is operated by an external command input, a changeover switch, and other control unit devices. In this way, set the offset measurement time according to the required measurement accuracy,
Improve gyro operation convenience. That is, the offset measurement time is set according to the stationary time of the moving body on which the gyro is installed and the time between the stationary and the next stationary. In general, when the offset measurement time is shortened, by making the interval for performing the offset removal processing short and frequent, the angle drift does not diverge, and good measurement accuracy can be maintained. If the offset removal processing interval cannot be shortened, the offset measurement accuracy is increased by increasing the offset measurement time.

Further, the setting of the offset measurement time can be left to the self-diagnosis of the gyro itself. That is, a self-diagnosis unit for measuring the output noise amount of the gyro and setting an optimum offset measurement time according to the noise amount is provided. This self-diagnosis unit is built in the gyro, or a self-diagnosis process corresponding to the amount of noise is performed by a CPU connected to the gyro. These self-diagnosis units can be easily realized by a conventionally used technique.

[0024]

As described above, the present invention measures the angular velocity offset of a gyro, and removes the angular velocity offset by arithmetic processing, thereby eliminating the use of an expensive mechanical part of the gyro. In addition, a gyro having a relatively high accuracy can be constructed at low cost as a whole gyro.

By setting a dead zone in the angular velocity signal obtained as a result of the angular velocity offset removal, even if a repetitive right and left rotational movement such as a pendulum movement is input, the detected angular velocity in the left and right direction can be balanced and the angular integration can be achieved. No error will occur. Similarly, a gyro can be provided in which the influence of the earth rotation is removed by setting the dead zone.

Further, by making the offset measurement time variable, it is possible to carry out optimal offset removal adapted to the operating state of the moving body having the gyro.

[Brief description of the drawings]

FIG. 1 illustrates an embodiment.

FIG. 2 is a diagram illustrating another embodiment.

[Explanation of symbols]

 1 mechanical section of gyro 2 offset removal processing section 3 offset measurement processing section 4 integration processing section 5 insensitive processing section

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mitsutoshi Sato 1-21-2 Dogenzaka, Shibuya-ku, Tokyo Inside Japan Aviation Electronics Industry Co., Ltd. (72) Inventor Toshio Sekiya 1-21-2 Dogenzaka, Shibuya-ku, Tokyo Japan Aviation Electronics Industry, Ltd.

Claims (11)

[Claims] 1. A method for detecting and measuring a rotational angular velocity, wherein when detecting and measuring a rotational angular velocity of a moving body by a gyro, an offset removing process for a detected angular velocity signal output from a mechanical part of the gyro is periodically and frequently performed. . 2. A gyro for detecting and measuring a rotational angular velocity of a moving body, comprising: an offset measurement processing section for inputting a detected angular velocity signal output from a mechanical section of the gyro and measuring an offset, and outputting the mechanical section of the gyro. A gyro, comprising: an offset removal processing unit that receives a detected angular velocity signal and inputs an offset output from an offset measurement processing unit to perform an offset removal process on the detected angular velocity signal. 3. The gyro according to claim 2, further comprising an integration processing section for integrating an angular velocity output of the angular velocity offset removal processing section. 4. The gyro according to claim 2, wherein the CPU performs arithmetic processing for offset removal and angular velocity integration.
A gyro, comprising: 5. The gyro according to claim 2, wherein the angular velocity is integrated during an offset measurement time that is a predetermined time, and the angle at the integration start time and the angle at the integration end time are calculated. A gyro, wherein an angular difference is divided by an offset measurement time to calculate an angular velocity offset value, and the offset is removed by subtracting the angular velocity offset value from the measured angular velocity. 6. The gyro according to claim 2, wherein the mechanical part of the gyro is any one selected from an optical fiber gyro, a vibration gyro, and a silicon gyro. A gyro that features. 7. A gyro according to claim 2, wherein an angular velocity output resulting from the angular velocity offset removal in said offset removal processing section is input to a gyro and a dead zone is set therein. A gyro characterized by comprising a part. 8. The gyro according to claim 7, wherein the insensitive processing section is connected to the integration processing section, and the angular velocity output subjected to the insensitive processing is input. 9. The gyro according to claim 5, wherein the gyro is configured to vary an offset measurement time. 10. The gyro according to claim 9, wherein the offset measurement time is changed by an externally input command or a changeover switch. 11. The gyro according to claim 9, further comprising a self-diagnosis unit for setting an optimum offset measurement time.