JPS6288903A - Body position detecting device - Google Patents

Abstract

PURPOSE:To detect electrically the position of a body which moves at a high speed such as a blade by detecting a quantity corresponding to the distance from the reference point in a visual field to a point to be measured on the body from the video signal of a linear image pickup device and a scan correspondence signal. CONSTITUTION:The disk 51 of a rotor sensor is rotated in synchronism with a rotor 5. Two couples of light sources 52 and photodetectors 53 are arranged across the disk 51 of the rotor sensor. The output of one photodetector 53 is utilized to lock the rotor and the output of the other photodetector 53 is utilized as a reset pulse G. A peak detecting circuit 65 selects and outputs a maximum value among held signals. This signal D is sent out to a multiplexer 7 with a rotor clock F from the rotor sensor and outputted as a serial or parallel signal. Resetting operation is performed with the reset pulse G after signals corresponding to all blades are outputted, and the 1st operation is restarted. Consequently, the position of a body which moves fast such as a blade is detected electrically.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an object position detection device suitable for detecting mutual positional deviation between blades of a helicopter rotating at high speed.

(Prior Art) The tip of a helicopter blade rotates at an opening speed close to the speed of sound, and the air vortex generated at the tip creates a large resistance and vibrates.

For this reason, the blade not only rotates when being driven, but is also constantly subjected to mechanical vibrations.

In order to prevent the blade from breaking due to total bending fatigue of the blade material due to this vibration, it is necessary to replace the rotor periodically.

Helicopters control lift by changing the pitch of the blades, so when the rotor is replaced it must be adjusted to equalize the load on all blades during rotation.

A helicopter has 2 to 8 blades depending on the type of blade, and if one of the blades has a larger pinch angle than the others, the load on that one blade will be greater and it will warp more upwardly than the other plates.

Therefore, greater stress is applied than the other blades, and if one of them were to break, the rotational balance would be lost and the rotor would disintegrate in the air, resulting in a fatal accident.

In order to ensure safe flight of a helicopter, it is necessary to accurately adjust the blades.

For this reason, conventionally, when replacing the rotor, a strobe light is emitted in synchronization with the rotation of the rotor, the blades are visually observed, and adjustments are made so that all the blades are on the same rotational surface.

(Problems to be Solved by the Invention) According to the above-described method, a skilled maintenance person can qualitatively know the condition of the blades of a helicopter, and can adjust the rotor etc. based on the result.

However, with this method, accurate measurement of the rotation surface is impossible.

Further, there is a problem in that adjustment using the above method takes a considerable amount of time.

Also, the method cannot be carried out in helicopter flight conditions.

An object of the present invention is to provide an object position detection device that can electrically detect the position of an object moving at high speed, such as a blade.

(Means for Solving the Problems) In order to achieve the above object, the object position detection bag T according to the present invention includes a one-dimensional imaging device that images an object entering the field of view multiple times each time it enters the field of view, and a one-dimensional a scanning-compatible signal generation circuit that generates a scanning-compatible signal whose magnitude changes over time in synchronization with the scanning cycle of the imaging device; A sample-and-hold circuit detects a quantity corresponding to the distance to a point on an object to be measured, samples and holds it for each scan, and generates a plurality of sample-and-hold outputs; It consists of a peak detection circuit that outputs the value or minimum value.

(Example) Hereinafter, the present invention will be described in more detail with reference to the drawings and the like.

FIG. 1 is a schematic diagram showing the relative position of a one-dimensional CCD camera, which is an embodiment of the imaging unit of the object position detection device according to the present invention, and a helicopter blade.

A one-dimensional CCD camera 3 is mounted inside the helicopter 1 so that the tip of the blade 2 in various rotational states can be seen in its field of view 4. FIG. 3 is a waveform diagram showing the scanning relationship.

The scanning direction of the one-dimensional CCD camera 3 is always from bottom to top in the left-hand diagram of FIG. 2, and the blade 2 that enters its field of view is imaged.

Although this figure depicts a large number of scanning lines, in reality the CCD is fixed, and for convenience, one of the blades 2 is shown rotating from left to right.

At this time, the output signal of the CCD camera 3 is only for the portion corresponding to the blade 2, t1 to 12, 1, as shown in the figure cloth.
．． As shown in ~t5, multiple pieces of blade 2 can be seen at the same time.

As a result, for each blade 2, its lower end t,
t4. t7 can be detected.

FIG. 3 is a block diagram showing an embodiment of the circuit of the object position detection device according to the present invention.

An example of a helicopter with four blades will be explained.

FIGS. 4 and 5 are waveform diagrams showing signal waveforms of each part in the block diagram.

Next, the embodiment circuit will be explained with reference mainly to FIGS. 3, 4, and 5.

An imaging signal A from a one-dimensional CCD camera 3 forming a one-dimensional imaging device is input to a comparator 61 of a position processing circuit 6, and a synchronization signal is input to a pulse forming circuit 9.

The sawtooth wave generating circuit 66 of the position processing circuit 6 generates a pulse forming circuit 9 in synchronization with the scanning of the one-dimensional COD camera 3.
A sawtooth wave is output based on the reset pulse VD2 generated by , forming the scanning compatible signal generation circuit of the present invention.

The imaging signal A from the one-dimensional CCD camera 3 is converted into a binary signal by a comparator 61 (the level of a pixel without a blade image is O, and the level of a pixel with a blade image is 1).

The level of the sawtooth wave generated by the sawtooth wave generation circuit 66 is sampled and held by a sample and hold circuit 63.

The output of the sample and hold circuit 63 is shown in FIG. 4B.

Furthermore, by the pulse VDI created by the pulse forming circuit 9,
The next sample-and-hold circuit 64 is operated to extract only the held level.

The output of this sample and hold circuit 64 is shown in FIG. 4C.

FIG. 6 is a plan view showing an embodiment of the disk of the rotor sensor.

The disk 51 of the rotor sensor is rotated in synchronization with the rotor 5 (see FIG. 3).

Two pairs of light sources 52 sandwiching the disk 51 of the rotor sensor
and a photodetector 53 are arranged.

The output of one photodetector 53 is used as a rotor clock F, and the output of the other photodetector 53 is used as a reset pulse G.

The peak detection circuit 65 selects and outputs the maximum value of the held signals (FIG. 5D).

In this way, a signal corresponding to one blade was obtained.

This signal is sent to the multiplexer 7 by the rotor clock F from the rotor sensor mentioned above, and is output as a serial signal or a parallel signal (Fig. 5E
).

After outputting signals corresponding to all the blades, it is reset by a reset pulse G and returns to the initial operation.

In the above manner, the signal shown in FIG. 5E is obtained on the monitor 8, which corresponds to the distance of the lower end of each blade from a certain reference point.

Therefore, if these levels are all at the same level, there will be no discrepancy in the pitch angle between the blades.

Actually, while watching this monitor 8, the rotor is adjusted so that these levels are all the same.

In the above-mentioned embodiment, in order to know the position of the blade, it is possible to measure the position by scanning the blade 2 two to three times, so when the rotation of the blade 2 is 200 to 300 PPM, the clock frequency of the COD is 2 to 5 KHz is sufficient.

In this case, a 256 or 512 bit COD is used.

Further, the position of the tip of the blade is determined by many factors such as the attitude of the rotor (tilting forward when moving forward, tilting backward when moving backward), the bending of the blade, and the vibration of the tip. Large aircraft can move several meters, so field-of-view tracking may be necessary.

In this case, the CCD camera 3 may be installed on a tracking servo stand.

(Effects of the Invention) As explained in detail above, the object position detection device according to the present invention includes a one-dimensional imaging device that images an object that enters the field of view multiple times for each entry, and a scanning period of the one-dimensional imaging device. a scan-compatible signal generation circuit that generates a scan-compatible signal whose magnitude changes over time in synchronization with the image pickup device; It includes a sample-and-hold circuit that detects a quantity corresponding to the distance to a point, samples and holds it for each scan, and generates a plurality of sample-and-hold outputs.

Therefore, each time an object such as a helicopter blade enters the field of view of the one-dimensional imaging device, the amount corresponding to the distance from the reference point in the field of view to the blade is detected, and a sample is held for each scan to create multiple sample holds. can generate output.

Furthermore, the object position detection device according to the present invention includes a peak detection circuit that outputs the maximum value or minimum value from among the plurality of sample-and-hold outputs for each intrusion.

Therefore, each time an object such as a helicopter blade enters the field of view of the one-dimensional imaging device, the maximum or minimum value of the deflection can be detected and output.

By using the above device to detect deflection of a helicopter blade, the tip position of a helicopter blade can be electrically measured accurately and quickly.

Furthermore, it is also possible to measure the rotational surface and vibration of the blade in various flight conditions.

Therefore, adjustment data for helicopter blades can be easily obtained, which can greatly contribute to safe helicopter flight.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the relative position of an embodiment of an imaging unit of an object position detection device according to the present invention and a blade of a helicopter. Figure 2 shows a helicopter blade and a one-dimensional CCD (fi
FIG. 3 is a waveform diagram showing the scanning relationship of the (I image portion). FIG. 3 is a block diagram showing an embodiment of the circuit of the object position detection device according to the present invention. FIGS. 4 and 5 are waveform diagrams showing signal waveforms of each part in the block diagram. FIG. 6 is a plan view showing an embodiment of the disk of the rotor sensor. ' 1...Helicopter 2...Blade 3...One-dimensional CCD camera 4...Field of view of one-dimensional COD camera 5...Rotor 51...Rotor sensor disk 52...Light source of rotor sensor 53...Photodetector of rotor sensor 6...Position process circuit 61...Comparator 62...Flip-flop 63.64...Sample hold circuit 65...Peak detection circuit 66...Sawtooth Wave generation circuit 7... Multiplexer 8... Monitor 9... Pulse forming circuit VDI, VD2... Pulse forming circuit output A... Imaging signal (COD output) B... Sample hold circuit 63 Output C... Output D of sample hold circuit 64... Peak detection circuit 6
5 output E...Multiplexer output F...Rotor clock (rotor sensor output) G...
Reset pulse (rotor sensor output) Patent applicant Hamamatsu Photonics Co., Ltd. Agent Patent attorney Inoro Jusai Figure 11

Claims (2)

[Claims] (1) A one-dimensional imaging device that images an object entering the field of view multiple times each time it enters the field of view, and a scanning device that generates a scanning-compatible signal whose size changes over time in synchronization with the scanning cycle of the one-dimensional imaging device. A corresponding signal generation circuit detects a quantity corresponding to the distance from a reference point in the field of view to a point to be measured on the object from the video signal of the one-dimensional imaging device and the scanning corresponding signal, and samples and holds the detected quantity for each scan. An object position detection device comprising a sample hold circuit that generates a plurality of sample and hold outputs, and a peak detection circuit that outputs a maximum value or a minimum value from among the plurality of sample and hold outputs for each intrusion. (2) The object position detection device according to claim 1, wherein the object entering the field of view is a helicopter blade.