JPS63275913A - Inclinometer - Google Patents

Abstract

PURPOSE:To enable the measurement of a constantly correct angle of inclination and also to improve the stability of operation, by a method wherein an output of an accelerometer being sensitive to the inclination of a running vehicle is corrected by an output of a running speed meter and an output of a gyrosensor detecting a gyratory angle speed. CONSTITUTION:A gyratory angle detection output of a gyrosensor 2 and a detection output of a speed meter 3 are supplied to an adder 5 through a multiplier 4, and an output of an accelerometer 1 being sensitive to the inclination of a running vehicle is corrected thereby in the adder. This corrected output is calibrated with a gravitational acceleration in a coefficient unit 6 and subjected to inverse sine conversion in a signal converter circuit 7, and thereby it turns to be a constantly correct angle of inclination which is not affected by an acceleration due to a change in a speed and by a gyratory acceleration at the time of turning of the running vehicle. In addition, the stability of operation is improved by this construction having no sliding element.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an inclinometer that is mounted on a vehicle running on a road with a cross slope and measures the inclination angle of the vehicle, particularly when the vehicle is turning. This invention relates to preventing measurement errors caused by acceleration when increasing or decelerating the traveling speed.

[Prior Art] FIG. 7 is a block diagram of a conventional tilt exercise, for example. In the figure, 26 is a two-degree-of-freedom gyro that measures tilt angles in two directions, pitch angle and roll angle, from the vertical axis, and an upright device. The vertical gyro 26 is conventionally used as an inclinometer to measure the inclination angle of a vehicle running on a road with a cross slope. The vertical gyro 26 uses the inertia of a rotor that rotates at high speed to keep the spin axis constant in space, and uses an upright device to always align the spin axis with the vertical axis. As a reference, the angle of inclination has been measured by measuring the direction in which the vehicle is traveling and the direction perpendicular thereto, that is, the pitch angle and roll angle.

In order to always align the spin axis of the gyro with the direction of the vertical axis, the vertical gyro 26 uses an upright device as its tracking mechanism. To detect the inclination angle of the upright device, an electrolyte level detector was used, for example, in which electrodes were provided at both ends and the center of a bent glass tube, and air bubbles and electrolyte were sealed in the tube. When the vertical gyro 26 tilts and the bubble moves,
When the internal resistance changes and deviation from the equilibrium state is detected, a torque is generated in the torque motor to perform standing control.

Since the orthostatic device is sensitive to accelerations other than those in the vertical direction,
When an increase/deceleration acceleration is added to the rotational acceleration or running speed during turning from the running state of the running vehicle, the spin axis attempts to follow the resultant direction, causing an error in measuring the inclination angle using the vertical gyro 26. Therefore, when the error correction device is not used, the upright device may stop operating when turning, and the measurement of the inclination angle of the vehicle is temporarily interrupted.

[Problems to be Solved by the Invention] The conventional inclinometer as described above continuously measures the inclination angle of a vehicle traveling on a road with a cross slope. When increasing or decelerating, the upright device receives interference from rotational acceleration and increasing/decelerating acceleration, and the spin axis of the vertical gyro 26 used for the inclinometer cannot accurately follow the direction of the earth's gravity, resulting in measurement errors.

Therefore, if the measurement error is not corrected, the operation of the upright device must be stopped when the vehicle is turning or increasing or decelerating, and the measurement of the inclination angle must be interrupted. In other words, correct measurements cannot be taken while the vehicle is running.

In addition, since the vertical gyro 26 constantly rotates at high speed, drift may occur due to wear on the bearings.The rotating and sliding parts are subject to a limited wear life, and must be periodically maintained and inspected to ensure long-term stability. There was a problem that operation could not be obtained.

This invention was made in order to solve this problem, and the inclination angle of the 11 vehicles is always correct even when traveling without being interfered with by the rotational acceleration of the traveling vehicle when turning or the acceleration/deceleration acceleration of the traveling speed. The purpose of the present invention is to obtain an inclinometer that can perform measurements and operate stably for a long period of time without using rotating and sliding parts.

[Means for Solving the Problems] The inclinometer according to the present invention has an accelerometer that is sensitive to the inclination of a traveling vehicle, and is designed to eliminate the influence of interference between the rotational acceleration and acceleration/deceleration acceleration when the traveling vehicle turns. It is equipped with a speedometer that detects speed, a gyro sensor that detects turning angular velocity, and a signal conversion circuit that performs inverse sine conversion of a signal obtained by correcting the output of the hO speedometer using the output of the speedometer and the gyro sensor.

[Function] In this invention, the output of the accelerometer that is sensitive to the inclination of the vehicle is corrected by the signals of the speedometer that detects the traveling speed of the vehicle and the gyro sensor that detects the turning angular velocity when turning. Even if the vehicle turns or increases or slows down its running speed, the inclinometer is not affected by these changes, so it can always accurately measure the inclination angle of the vehicle.

[Example] An example of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, 1 is an accelerometer that outputs a signal responsive to the inclination angle of the vehicle, and 2 is a rate that detects the angular velocity when the vehicle is turning. A gyro sensor using a gyro, 3 a speedometer that detects the running speed of a traveling vehicle, 4 a multiplier, 5 an adder,
Reference numeral 6 indicates a coefficient unit, and reference numeral 7 indicates a signal conversion circuit for inverse sine conversion of the input signal.

In the inclinometer configured as described above, for example, when eight servo accelerators are used as the accelerometer 1, Fig. 2 shows an example of a configuration diagram of the servo accelerometer. A beam that is deflected in response to acceleration; 13 is a coil attached to the beam 12; 14;
15 is an optical pickup that detects the deflection of the pendulum; 16 is a case 11 on both sides of the coil 13;
The magnet provided at 17 indicates a servo amplifier, and when gravitational acceleration acts on a pendulum holding a heavy pyramid with a hinge 14, the pendulum is deflected, and a force or torque is generated to return the heavy forceps to its original equilibrium position. This is a force-balanced servo that measures the deviation from the feedback current that generates the output, and the output is obtained by calibrating the feedback current with the tilt angle.

The accelerometer 1, which is not shown above, does not use high-speed rotation or rotating sliding parts, and is only sensitive to acceleration in one direction, so it is installed in the direction of inclination.

Fig. 3 is an explanatory diagram when the vehicle is traveling. When the vehicle is traveling on a road with a cross slope, the output E of the accelerometer 1 is E=G Sinθ G; Gravitational acceleration 9.8 m/S2 θ: Traveling Inclination angle of the car Fig. 4 is an explanatory diagram when the running car is turning, and the output E of the accelerometer 1 is E = G Sinθ ±3 3: The sign of the rotational acceleration ± is determined by the turning direction. It is an explanatory diagram of the turning motion of the car, and the traveling speed V
The rotational acceleration when turning at +V °Q)) The inclination angle of the vehicle is determined as described above.

Therefore, the angular velocity ±ω whose polarity is determined by the turning direction during turning by the gyro sensor 2 and the traveling speed V signal by the speedometer 3 using a speed generator etc. are input to the multiplier 4, and the rotational acceleration is calculated from the product of the signals. Obtain Shi■・ω. The output E of the accelerometer 1 and the rotational accelerometer ■ and ω are input to the adder 5, and the added output is calibrated with the gravitational acceleration by the coefficient unit 6, and the signal conversion circuit 7
The inclination angle θ of the vehicle can be measured by inverse sine transformation.

FIG. 6 shows an example of a block diagram of a signal conversion circuit, and the signal conversion circuit 7 performs inverse sine conversion of an input signal.

In the figure, 7 is the same as in the above embodiment, 20 is an operational amplifier, 21 is a subtracter, 22 is an inverting operational amplifier, 2
3 indicates a sine circuit.

For example, when performing signal conversion of θ=5in-IA, when A is added to the input of the operational amplifier 20, the subtractor 2
1 and is input to the operational amplifier 22. Operational amplifier 22
forms an integrating circuit, and outputs an angle signal θ via a variable resistor R.

On the other hand, the angle signal θ is converted into a sine signal in the sine circuit 23, passed through the coefficient unit 7, and is calculated with the output of the operational amplifier 20 in the subtracter 21, and when the difference signal becomes zero, the angle signal θ of the integration circuit output is The output of the sine circuit 23 becomes equal to the input signal A.

Therefore, the angle signal θ of s r n-1A of the input signal @A becomes an output calibrated with the sine signal of the corresponding angle.

Unlike conventional inclinometers, the inclinometer according to the present invention does not use an upright device, so the inclination angle measurement is not temporarily interrupted. Therefore, by installing it in the direction of inclination to be measured, it will not be affected by acceleration/deceleration in the running direction.

When a vehicle makes a turn while driving on a road with a cross slope,
An error occurs in the measurement of rotational acceleration or IJn twist on the inclinometer, but
Since it is corrected by the output signals of the gyro sensor 2 and speedometer 3, the inclinometer can always output a correct inclination angle signal of the vehicle.

Furthermore, when the vehicle makes a turn while driving on a flat road, the vehicle tilts and the bank angle of the vehicle can also be measured.

Accelerometer 1 does not rotate at high speed, and gyro sensor 2
By using a photographic gyro or a gas rate gyro, there are no rotating and sliding parts, so there is no drift caused by friction on the bearing, and there is no limit to the wear life. Therefore, the period of maintenance and inspection can be extended, and the maintenance period can be extended for a long time. Stable operation is possible.

As mentioned above, even when a vehicle makes a turn and at the same time increases or decelerates its traveling speed, the vehicle's inclination angle corresponding to the cross slope can always be measured, and the inclination angle of the road can also be measured at the same time. It prevents the risk of falling and allows safe driving at all times.

The present invention relates to an inclinometer for vehicles running on roads with a cross slope, but can also be applied to measuring inclination angles of vehicles running on roads with a vertical slope.

[Effects of the Invention] As described above, the inclinometer mounted on the vehicle includes an accelerometer that outputs the tilt angle signal of the vehicle, a gyro sensor that detects the turning angular velocity, and a speed that detects the traveling speed. With a simple structure that includes a sensor and a signal conversion circuit, the accelerometer output is corrected and converted into a signal by the gyro sensor and speedometer output even if rotational acceleration when the vehicle turns or acceleration or deceleration is applied in the direction of travel. Since the angle of inclination of the vehicle is obtained, there is no measurement error in the inclinometer and the W is always correct.
It is possible to measure the inclination angle of the vehicle and the road.

Furthermore, since no upright device is used, even if acceleration in a direction other than the direction of gravity is applied due to the movement of the vehicle, the tilt angle can be measured at all times without interrupting the measurement.

Furthermore, since accelerometers and gyro sensors do not rotate at high speeds like vertical gyros, there are no rotating and sliding parts, and there is no drift caused by friction in the bearings and no limitations on wear life, so maintenance and inspection periods can be extended. Can operate stably for a long time.

When driving on a flat road, the bank angle of the vehicle when turning can be measured, which has the effect of preventing the vehicle from falling over and contributing to safe driving of the vehicle.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing one embodiment of the present invention, Fig. 2 is an example of a configuration diagram of an accelerometer, Fig. 3 is an explanatory diagram when the vehicle is running, and Fig. 4 is an illustration when the vehicle is turning. FIG. 5 is an explanatory diagram of the turning motion of a traveling vehicle, FIG. 6 is an example of a block diagram of a signal conversion circuit, and FIG. 7 is a block diagram of a conventional inclinometer. In the figure, 1 is an accelerometer, 2 is a gyro sensor, 3 is a speedometer, 4 is a multiplier, 5 is an adder, 6 is a coefficient unit, and 7 is a signal conversion circuit. Note that the same reference numerals in each figure indicate the same or corresponding parts. Patent applicant Tokyo Co., Ltd. Instrument Figure 1 Figure 2 Figure 6 Figure 7

Claims (1)

[Claims] An inclinometer that is mounted on a vehicle and measures the angle of inclination of the vehicle includes an accelerometer that is sensitive to the inclination of the vehicle, a speedometer that detects the speed of the vehicle, and a turning angular velocity of the vehicle. and a signal conversion circuit that performs inverse sine conversion, the outputs of the speedometer and the gyro sensor are multiplied and added to the accelerometer output, and the added output is subjected to inverse sine conversion in the signal conversion circuit. An inclinometer characterized by: