JPH08110225A - Tilt angle measuring device - Google Patents

Abstract

(57) [Abstract] [Purpose] Even when vibration is applied, the noise component mixed with the vibration is removed, and the bias voltage of the gyro is removed to obtain a stable and accurate tilt angle signal. An inclination angle measuring device that can be obtained is provided. [Structure] First composed of accelerometer or inclinometer
The tilt angle sensor 11, the low-pass filter 13 that removes noise components that are superimposed on the angle signal output from the first tilt angle sensor, the second tilt angle sensor 21 including an angular velocity meter, and the second tilt angle sensor. The high pass filter 23 removes the bias voltage generated from the high pass filter, the integrator 25 that integrates the output of the high pass filter to convert it into an angle signal, and the adder 15 that adds the outputs of the low pass filter and the integrator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tilt angle measuring device which can be used for detecting the tilt angle of a device having a strong vibration such as a construction machine.

[0002]

2. Description of the Related Art For example, a construction machine such as a pile driver is required to maintain its posture vertical to the ground. In such a case, the tilt angle measuring device is mounted, the posture of the machine, that is, the tilt angle is measured, and the posture control is realized by using the measurement result. 4 and 6 show the structure of a conventional inclination angle measuring device.

Reference numeral 1 shown in FIG. 4 indicates a tilt angle sensor. The tilt angle sensor 1 is configured by, for example, an inclinometer that can be configured by a combination of a pendulum and a potentiometer, or an accelerometer that can be configured by a combination of a weight and a load sensor. Angle signal 2 detected by tilt angle sensor 1
(FIG. 5A) is taken out as the angle signal 4 shown in FIG. 5B through the low pass filter 3 and is output from the output terminal 5. The low-pass filter 3 is inserted to remove the noise component Noise shown in FIG. 5A generated by the vibration of the mounted machine.

FIG. 6 shows a case where an angular velocity meter is used as the tilt angle sensor 1. As an angular velocity meter, for example, an optical fiber is wound in a coil shape, right-handed light and left-handed light are passed through the optical fiber coil, and a clockwise input and a left-handed light are provided by applying a rotation input to the optical fiber coil in the circumferential direction of the coil. An angular velocimeter having a structure that detects the occurrence of a phase difference in the surrounding light and detects the rotational angular velocity can be used.

Therefore, in the case of FIG. 6, the inclination angle sensor 1
The output signal is the angular velocity signal 6 shown in FIG. 7A.
The angular velocity signal 6 is input to the integrator 7 and converted by the integrator 7 into the angle signal 8 shown in FIG. 7B, and the angle signal 8 is output from the output terminal 5.

[0006]

In the example shown in FIG. 4, the low-pass filter 3 is used to remove the noise component Noise superimposed on the angle signal 2 output from the tilt angle sensor 1. As the noise component Noise is removed by the low-pass filter 3, the angle signal 4 is shown in FIG.
As shown in B, a delay time τ occurs, and due to this delay time τ, for example, the responsiveness of attitude control deteriorates.

On the other hand, when an angular velocity meter is used for the tilt angle sensor 1 as in the example shown in FIG. 6, the angular velocity signal 6 includes a bias voltage 9 as shown in FIG. 7A. Is integrated by the integrator 7, and as shown in FIG. 7B, the angle signal 8 gradually changes in the increasing or decreasing direction with the passage of time. An object of the present invention is to eliminate these disadvantages, to prevent a delay in the angle signal, and to prevent the angle signal from unilaterally increasing or decreasing by the bias voltage 9. It is intended to provide an angle measuring device.

[0008]

According to the present invention, a first tilt angle sensor and a second tilt angle sensor are provided. The first tilt angle sensor includes an accelerometer or an inclinometer. The second tilt angle sensor is composed of an angular velocity meter. The angle signal output from the first tilt angle sensor is given to the low-pass filter, and the noise component generated by the vibration superimposed on this angle signal is removed.

On the other hand, the angular velocity signal output from the second tilt angle sensor is given to a high-pass filter which blocks passage of signals of a predetermined frequency or lower (including the frequency of the noise component),
The output of the high pass filter is integrated by an integrator and converted into an angle signal. By adding this angle signal and the angle signal output from the low-pass filter by the adder, it is possible to obtain an angle signal that changes at a timing without delay with respect to the change in the tilt angle. Of course, the angle signal does not include a noise component generated by the applied vibration and a drift that causes the angle signal to unilaterally increase or decrease due to the bias voltage generated by the gyro. Therefore, a stable tilt angle signal can be obtained.

[0010]

FIG. 1 shows an embodiment of the present invention. In the present invention, the first tilt angle sensor 11 and the second tilt angle sensor 21 are provided. The first tilt angle sensor 11 uses an accelerometer or an inclinometer. The second tilt angle sensor 21 uses the angular velocity meter as described with reference to FIG. The first tilt angle sensor 11 and the second tilt angle sensor 21 are mounted on a base 28 as shown in FIG. That is, the tilt sensing direction X of the first tilt angle sensor 11
Then, the input rotation surface Ω of the second tilt angle sensor 21 is arranged so as to exist in parallel planes. When placed in this way,
As shown in FIG. 2, the base 28 is, for example, α ° in the clockwise direction.
If tilted, the angle signal 12 and the angular velocity signal 22 are output from the first tilt angle sensor 11 and the second tilt angle sensor 21.

A noise component Noise generated when the vibration 29 shown in FIG. 2 is applied to the base 28 is superimposed on the angle signal 12 output from the first tilt angle sensor 11, as described with reference to FIG. . This noise component is removed by the low pass filter 13 and input to the adder 15. The angle signal 14 input to the adder 15 is a noise component Nois.
Instead of removing e, as shown in FIG.
have.

On the other hand, the second inclination angle sensor 21 outputs an angular velocity signal 22 shown in FIG. 3C. This angular velocity signal 22
Does not include a noise component associated with the vibration 29. That is,
Since the vibration 29 only gives parallel movement to the input rotation Ω of the second tilt angle sensor 21, even if the vibration 29 is given, its response signal is not output. Therefore, the angular velocity signal 22 of the second tilt angle sensor 21 becomes a signal as shown in FIG. 3C. When the angular velocity signal 22 does not exist, the bias voltage 9 of the angular velocity meter is output.

The bias voltage 9 is removed by a high-pass filter 23 which removes signal components below a predetermined frequency, and an angular velocity signal 24 shown in FIG. 3D is obtained. This angular velocity signal 24
Is integrated by an integrator 25 (or may be a low-pass filter) to convert into an angle signal 26 shown in FIG. 3E. By adding the angle signal 26 and the angle signal 14 obtained by the low-pass filter 13 by the adder 15, the tilt angle signal 27 shown in FIG. 3F can be obtained at the output terminal 30. This tilt angle signal 27 becomes the angle signal without delay by removing the delay time τ of the angle signal 22 shown in FIG. 3B.

[0014]

As described above, according to the present invention, it is possible to obtain the stable tilt angle signal 27 in which the noise component Noise caused by the vibration 29 and the error caused by the bias voltage 9 of the angular velocity meter are eliminated. Therefore, the correct tilt angle can be measured by applying it to a construction machine or the like where vibration is severe.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining an embodiment of the present invention.

FIG. 2 is a side view for explaining the arrangement of first and second tilt angle sensors used in the present invention.

FIG. 3 is a waveform chart for explaining the operation of the embodiment shown in FIG.

FIG. 4 is a block diagram for explaining a conventional technique.

FIG. 5 is a waveform chart for explaining the operation of FIG. 4;

FIG. 6 is a block diagram showing another example of the conventional technique.

7 is a waveform diagram for explaining the operation of FIG.

[Explanation of symbols]

 11 First Tilt Angle Sensor 13 Low Pass Filter 15 Adder 21 Second Tilt Angle Sensor 23 High Pass Filter 25 Integrator

Claims (1)

[Claims] 1. A. First Embodiment A first tilt angle sensor composed of an accelerometer or an inclinometer, and B. A low-pass filter for removing a vibration component from the tilt angle signal output from the tilt angle sensor; A second tilt angle sensor configured by an angular velocity meter that detects rotational acceleration in a plane parallel to the measured tilt direction of the first tilt angle sensor; A high-pass filter that removes a fluctuation signal having a frequency equal to or lower than a predetermined frequency from the measurement output of the second tilt angle sensor; An integrator that integrates an angular velocity signal obtained from this high-pass filter, and F. A tilt angle measuring device comprising an adder for adding the integrated output of the integrator and the output of the low-pass filter.