JPS62102128A - Method and instrument for measuring partial pressure - Google Patents

Abstract

PURPOSE:To remove the influence of vibration applied to a fixing part and to reduce a measuring error by measuring component force applied to an object in a required axial direction, measuring acceleration in the same axial direction which is generated by the vibration of the fixing part and executing the arithmetic processing of both the measured values. CONSTITUTION:An air duct testing model 2 is fitted to the surface of a multi- component force detector 1 for detecting 6 component force. The model 2 is arranged in an air duct 3 and air is carried in the white arrow direction. The detector 1 is fixed on a fixed base 4. In the detector 1, the output of a component force detector 31 for detecting component force in a required direction is amplified by an amplifier 32 and the amplified signal is applied to one terminal of an adder 33. The output of an acceleration detector 34 for the component force in the same direction is level-regulated by an amplifier 35 and an output gain-regulated by an output voltage adjuster 36 is supplied to the other terminal of the adder 33. The output of the adder 33 is level-adjusted by an amplifier 37 and outputted to an output terminal 38. Even in a place having large external vibration, multi-component force can be detected without the influence of vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a component force measuring method and apparatus using a component force detector.

In recent years, measurements using component force detectors have become widespread. The multi-force detector is X.

The purpose is to detect component forces acting on each of the Y and Z three axes as respective forces and moments, and to accurately measure the overall state of force acting on the relevant region. In this case, if the fixed base part on which the component force detector is attached vibrates, the influence of the vibration will appear as an error, making it impossible to perform accurate measurements.

An object of the present invention is to provide a method and a device for reducing measurement errors in measurements made by a component force detector attached to a fixed base that vibrates as described above.

The purpose is to provide a force measuring method and device having the structure set forth in the claims, that is, to measure a desired axial component of force acting on an object, and at the same time to measure the acceleration in the same axial direction caused by vibrations of a fixed part. A component force measuring method that removes the influence of vibrations acting on a fixed part by measuring and calculating both measured values, a component force measuring device that measures a desired axial component force acting on an object, and a fixed part This is achieved by a component force measuring device that includes an acceleration measuring device that measures acceleration in the same axial direction of the fixed portion caused by vibration of the fixed portion, and an arithmetic circuit that processes the outputs of both measuring devices.

According to the component force measurement method and device according to the present invention, even when vibrations of various components act on the component force detector fixing base, component force measurement with few errors is possible.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A component force measuring method and device according to the present invention will be described below with reference to the accompanying drawings showing examples.

FIG. 1 shows a state in which a multiforce detector measures component forces acting on an aircraft model within a wind barrel. In the figure, a wind tunnel test model 2 is mounted on a multi-force detector 1 for detecting six component forces. The model 2 is inside a wind tunnel 3, and air is blown in the direction shown by the white arrow. Note that the multi-force detector 1 is mounted on a fixing foundation 4.

As the multiforce detector 1, a strain gauge type or a piezoelectric element type is widely used, but approximately 1 in each component force direction.
It is thought that elastic bodies with degrees of freedom are combined. The same applies to moment measurement. In addition to the above-mentioned type, a spring type or other type can be used as the multi-force detector as long as it can convert displacement into a load.

FIG. 2 shows a conceptual diagram of a component force detector in the X direction. According to FIG. There is. Assuming that the motion of the object 12 from a resting state is X and the motion of the fixed side 13 is x2, the equation of motion in this case becomes a second-order differential equation as shown below, if friction loss is ignored.

Assuming that the vibration x2 on the fixed side is the following formula, x2=Xz
sin art (2
)=KX, Sinωt (3), and the acceleration of x2 is as follows.

αxzSin ωt = -X2 ω"5in6Jt Substituting this equation (4) into equation (3), this equation (5) is the forcing force of the above one degree of freedom system, or the equation. Solution of equation (5) is as follows.

− to αxz/ω21 ・Sinωt ω2　1−ω2/ω. ′ Here, ω(1″=Kg/M).

The error force F measured by the detector due to vibration on the fixed side is g ωt 1−ω2/ω. 'Sinω becomes AF=--or B-5inωt (7). This equation (7) shows that the error force generated in the detector when the fixed side is vibrating is proportional to the acceleration of the fixed side.

Therefore, by installing an accelerometer in the X direction on the fixed side and calculating its output with the output of the load detector as shown in Figure 3, the output can be made unaffected by vibrations on the fixed foot side. can do. In the figure, the output of a component force detector 31 in a desired direction in a multiforce detector is amplified by an amplifier 32 and then applied to one terminal of an adder 33. The other terminal of the adder 33 is supplied with an output whose level is defined by an appropriate amplifier 35 and whose gain is adjusted by an output voltage regulator 36 from an acceleration detector 34 for component forces in the same direction.

An output terminal 38 receives the output of the adder 33 adjusted to an appropriate level by an amplifier 37.

Thus, according to the method and apparatus according to the present invention,
Even in locations with severe external vibrations, multi-force detection is possible without being affected by vibrations. Therefore, it is possible to accurately detect multiple forces in areas with vibration, which was previously considered impossible, and a new aspect will be developed in the field of measurement technology.

[Brief explanation of drawings]

FIG. 1 shows a state in which a component force detector is used to measure component forces acting on an aircraft model within a wind barrel. FIG. 2 shows a conceptual diagram of the X-direction component force detector. FIG. 3 is a block diagram showing an example of an arithmetic circuit for implementing the method according to the invention. The correspondence of the main reference symbols in the figure is as follows. 11-Elastic body 12: Object 13: Fixed side

Claims (1)

[Claims] 1. A method for measuring a component force acting on an object elastically supported by a fixed part, which measures a desired axial component force acting on the object and at the same time A component force measurement method characterized in that the influence of vibration acting on a fixed part is removed by measuring the acceleration in the same axial direction that occurs and calculating and processing both measured values. 2. In a device for measuring the component force acting on an object elastically supported by a fixed part, there is a component force measuring device that measures the desired axial component force acting on the object, and a component force measuring device that measures the component force acting on the object in the desired axial direction, and It has an acceleration measuring device that measures the acceleration in the same axial direction of the fixed portion, and an arithmetic circuit that processes the outputs of both measuring devices, and uses the calculated output to remove the influence of vibrations acting on the fixed portion. Features component force measuring device.