JPS63117211A - Clinometer - Google Patents

Abstract

PURPOSE:To obtain an apparatus permitting no intervention of an error even at the times of the advance and turning of a moving body, by correcting the angle of inclination of the moving body and the output signal of the acceleration sensor arranged to the moving body during running by the acceleration signal in the advancing direction. CONSTITUTION:An acceleration sensor 1 is arranged to a moving body and the displacement in inclination of the moving body with reference to the direction of gravity is detected. A speed sensor 2 is engaged with the running wheel of the moving body and the speed signal to an oblique surface of the moving body in the advance direction thereof proportional to the rotational speed of the wheel is generated. This voltage signal is differentiated to obtain the acceleration signal of the moving body in the advancing direction thereof. From the output signal of the sensor 1, only the acceleration signal in the advancing direction is subtracted by an operation circuit 4 and the effect of acceleration generated by the running or revolving motion of the moving body is removed and, further, when the moving body runs at a high speed, the acceleration component of the high frequency generated by the unevenness of the inclined surface is removed using a filter 5 and an accurate angle-of-inclination signal is outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application] The present invention relates to an inclinometer used for measuring the inclination angle of a slope on which a moving body is traveling, and particularly to inclination angle measurement while the vehicle is running.

[Prior Art] FIG. 4 is a sectional view of an acceleration sensor used in a conventional inclinometer, for example. In the figure, U is an acceleration sensor, 10 is a case, 11 is a beam that deflects in response to acceleration, 12 is a flexible hinge that supports the beam 11 to the case 10; 13 is a pair of one-position detectors that optically detects the deviation of the beam 11; 14 is fixed to the beam 11; A torquer coil that performs position control; 15 is a permanent magnet attached to the case 10 on both sides of the torquer coil 14; 16 is a permanent magnet that amplifies the unbalanced output of the deflection detector 13 and sends the output to the torquer coil 1;
4 is a servo amplifier, and 17 is an output circuit. The acceleration sensor unit used in a conventional inclinometer is constructed as described above. When acceleration occurs, since the case 10 is fixed to the moving body via the flexure hinge 12, the beam 11 to which the torquer coil 14 is fixed is accelerated, and the beam 11 is brought to an equilibrium point due to the mechanical force. deviate from.

The deviation position θ is detected by the deviation detector 13, converted into an electric signal, and inputted to the servo amplifier 16.The output of the servo amplifier 16 is fed back to the torquer coil 14.The output of the servo amplifier 16 is fed back to the torquer coil 14. generates a torque that restores it to its equilibrium position. Since this restoring current is proportional to the acceleration applied to the beam 11, a force balance type acceleration sensor unit is used which measures the restoring current and obtains an acceleration signal.

Therefore, the signal generated in the output circuit 17 is composed of the inclination angle signal of the acceleration sensor unit and the acceleration signal caused by running.

[Problems to be Solved by the Invention] In the conventional inclinometer as described above, the inclinometer installed on the moving object moves due to the acceleration/deceleration or turning motion of the moving object, except when the moving object is traveling at a constant speed. Acceleration occurs in the direction.

When a moving object runs on a slope, the acceleration sensor unit used in the inclinometer assumes an inclined position, and is further affected by the respective accelerations caused by the moving object or turning, so the output circuit 17 outputs the accelerations of both. Since the signals are generated in a superimposed manner, it is difficult to distinguish the acceleration signal due only to the tilted position, resulting in an error in measuring the tilt angle, and there is a problem in that the tilt angle cannot be measured accurately.

The present invention was made in order to solve such problems, and an object of the present invention is to provide an inclinometer in which errors do not occur even when a moving object is running or turning.

[Means for Solving the Problems] The inclinometer according to the present invention includes: an acceleration sensor installed on a moving body that outputs an acceleration signal in response to a tilt angle in the traveling direction with the direction of gravity as a reference; The vehicle is equipped with a speed sensor that detects the speed in the traveling direction, a differential circuit that converts the speed signal into an acceleration signal, and an arithmetic circuit that subtracts the differential circuit output signal from the acceleration sensor output signal.

[Operation] In this invention, an acceleration sensor and a speed sensor are installed in a moving object, and the speed sensor detects a speed signal of the moving object when traveling and turning, and this signal is differentiated to produce an acceleration signal, and the acceleration sensor The acceleration signal of the moving object obtained from the speedometer is subtracted from the output signal of the inclinometer, and the inclination angle signal, which is based on the direction of gravity and is not affected by the running or turning of the moving object, is obtained from the inclinometer output.

[Embodiment] FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, yu is exactly the same as the conventional device described above, 2 is a speed sensor that detects the traveling speed of a moving object, 3 is a differential circuit that converts the output signal of the speed sensor 2 into an acceleration signal; 4 is an arithmetic circuit that subtracts the output signal of the differential circuit 3 from the output signal of the acceleration sensor; and 5 is a filter that removes high frequency components.

In the inclinometer configured as described above, for example, an acceleration sensor unit is installed on the moving body to detect the tilt deviation of the moving body with respect to the direction of gravity.

The speed sensor 2 is, for example, a rotary generator or a rotary pulse generator that is attached to a running wheel of a moving body and generates a speed signal for a slope in the traveling direction of the moving body in proportion to the rotational speed of the wheel. A voltage proportional to the rotational speed of the wheel is generated, and since the rotational pulse generator generates a pulse signal proportional to the rotational speed, it is converted into a voltage signal using an F/V converter.

In either case, a voltage signal proportional to the traveling speed of the moving body is obtained, and by differentiating this voltage signal, a traveling acceleration signal in the traveling direction of the moving body can be obtained.

The horizontal cross-sectional shape of the beam 11, which is sensitive to the angle of inclination and the acceleration during running, is rectangular, and one end is connected to the flexure hinge 1.
Since the beam 1 is fixed to the case 10 via the beam 1
1 is deflected in the direction of arrow A-A, but not in the direction perpendicular thereto. Therefore, the structure is sensitive only to acceleration applied in a single direction in the direction of arrow A-A.

If the arrow A-△ is installed in the direction that matches the moving direction of the moving object, the acceleration sensor will be sensitive to inclination and acceleration in the moving direction of the moving object, but will not be sensitive to inclination and acceleration in the direction perpendicular to the moving direction. .

Figure 2 shows an example of the reference direction when a moving body runs in a straight line,
An acceleration 21 in the moving direction of the moving body is generated in response to an acceleration 20 in the direction of gravity, and the reference direction is deviated in the direction of the resultant acceleration 22.

Fig. 3 shows an example when a moving body turns. An acceleration 21 in the moving direction (linear velocity direction) of the moving body and an acceleration 22 in the centrifugal force direction perpendicular to this are generated. Since the structure is not affected by acceleration, it is only necessary to correct the acceleration 21 in the direction of travel.

A calculation circuit 4 subtracts only the forward direction acceleration signal obtained from the speed sensor 2 from the output signal of the acceleration sensor unit, which includes information on the inclination angle of the moving object and the acceleration generated by running. The effect of acceleration caused by motion is removed, and furthermore, when the moving body travels at a high speed, a high frequency acceleration component due to unevenness of the slope is generated in the output of the JJo speed sensor unit, so the filter 5 having low frequency passband characteristics is used. The result is an inclinometer that outputs the correct inclination angle signal.

Since the acceleration sensor unit is of a force balance type that feeds back the deflection signal of the heel 11, it has excellent operational stability, a wide acceleration response frequency, and high accuracy and resolution.

In addition to the above-mentioned sensor, the speed sensor 2 of the moving object may be provided with a speed sensor 2 that uses ultrasonic waves, optics, etc. to detect the relative speed between the slope and the moving object, and the same performance can be obtained.

As mentioned above, the acceleration that occurs during various operations related to the running of a moving object, such as starting, stopping, and shifting gears, as well as the effects of unevenness on slopes when moving at high speeds, are eliminated.
Since the correct direction of gravity can be detected, it is possible to measure the tilt angle of a moving object as precisely as when it is stationary, even when the object is moving.

The present invention installs an inclinometer on a moving body and can be applied to precise surveying that is not affected by acceleration when moving or turning. It is ideal for making precise measurements of small inclination angles over long distances, such as on expressways and railroad tracks, while the vehicle is running.

[Effects of the Invention] As explained above, the present invention transmits the output signal of an acceleration sensor installed on a moving body, which is sensitive to the inclination angle in the direction of travel and the acceleration during running, to the speed sensor attached to the wheels of the moving body. With a simple structure in which the output signal is corrected using a differentiated acceleration signal in the traveling direction, the output signal of the acceleration sensor installed on the moving object is only the inclination angle signal, and the output signal is only the inclination angle signal. The correct direction of gravity can be obtained without being affected by acceleration such as turning, and the tilt angle of the moving object can be measured using this direction as a reference, and the acceleration sensor can also receive a deflection signal. It is a force-balanced type that feeds back the current, and has excellent stability and frequency response, as well as high accuracy and resolution, so it is possible to precisely measure small angles of inclination over long distances and to minimize the effects of moving vehicles. It has the effect of being able to do it efficiently without being affected.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is an example of the reference direction when the moving body is running in a straight line, Fig. 3 is an example when the moving body is turning, and Fig. 4 is an example of the conventional tilting direction. This is a cross-sectional view of the h■ speed sensor used in the meter. In the figure, U is an acceleration sensor, 2 is a speed sensor, 3 is a differential circuit, 4 is an arithmetic circuit, 5 is a filter, and 7 is an output. Note that the same reference numerals in each figure indicate the same or corresponding parts. hmm

Claims (1)

[Claims] An acceleration sensor is installed on a moving object running on a slope and outputs an acceleration signal based on the direction of gravity in response to the inclination angle of the moving direction and the acceleration/deceleration of the moving object, and an acceleration sensor is installed on the moving object to detect the speed in the moving direction. An inclinometer comprising: a speed sensor that converts the output of the speed sensor into an acceleration signal; a differential circuit that converts the output of the speed sensor into an acceleration signal; and an arithmetic circuit that subtracts the output signal of the differential circuit from the output signal of the acceleration sensor.