DE1118509B - Photo camera for the objective measurement of the speed of watercraft - Google Patents

Description

GERMAN

PATENT OFFICE

P 21564 IXb / 42 ο

REGISTRATION DATE: OCTOBER 21, 1958

NOTICE THE REGISTRATION ANDOUTPUTE EDITORIAL: NOVEMBER 30, 1961

The invention relates to a photo camera for the objective measurement of the speed of moving vehicles Objects, especially watercraft, with the inside of the camera a uniform moving, provided with a time scale film tape is provided.

Knowing the exact speed of a watercraft is useful for both operational purposes also for scientific and technical work serving the advancement of the ship industry Meaning. Precise speed measurements are particularly important for the acceptance samples of newly built Vehicles, in the speed control of vehicles in operation, in the determination the dependence of the vehicles on the working parameters of the drive system and in the Calibration of ship boxes.

The previously known speed measurements are based either on the principle of determining the time, in which the vehicle covers a distance of known length, or on the exploitation other physical phenomena accompanying the movement of the hull on the water, which allow the quantitative representation of the magnitude of this movement. These known methods and those necessary for their implementation Devices allow the vehicle speed to be determined either in relation to the Water or in relation to the seabed. However, they differ from each other in terms of the achievable accuracy of the measurement, the range of its applicability as well as with regard to the investment and operating costs of the devices. So z. B. the lodge that the speed of the vehicle in relation to the water in general directly, in principle without Restriction may be applied, but the accuracy of their information is not very great.

In contrast, the "measuring mile" based on the optical basis determined by means of two axes can can be regarded as a significantly more accurate method, but only in the case of favorable coastal and basic conditions and with good visibility is applicable (measurement not far from Beaches). It is also a subjective method.

In other areas of technology there are already devices for measuring the instantaneous speed moving bodies known, in which worked with a light-sensitive film strip will. For example, there is a device for measuring the speed of pneumatic tube carriers Photo camera for the objective measurement of the speed of watercraft

Applicant:

Politechnika Gdanska Zaklad Elektrotechniki ίο Morskiej, Gdansk (Poland)

Representative: Dr. W. P. Radt, patent attorney, Bochum-Weitmar, Heinrich-König-Str. 12th

Claimed priority Poland from April 21, 1958

Dipl.-Ing. Jan Wysoczynski, Gdansk-Wrzeszcz,

and Henryk Markiewicz, Gdynia (Poland),

have been named as inventors

Known at any point on the tube, which is essentially a closed housing acts, in which a highly sensitive film strip by means of clockwork-driven rollers is moved, and in the interior of the housing one of an alternating current with 50 Hz powered glow lamp is provided, which exposes one half of the film through a slot. Below of the aforementioned slot, another slot is provided in the housing through which the other Half of the film is exposed by attaching the housing to the tube on opposite sides Bores is brought to cover. While blackening in the upper part of the film occur, the interval of which corresponds to the time of half an alternating current period, shows the lower one Part of the film has a continuous black stripe with an unexposed gap, the length of which corresponds to the time in which the pneumatic tube carrier covers the lower slot and thus an exposure has prevented the same. With the help of the time scale, the duration of the light beam interruption can be determined determine so that with a known length of the can also the speed of the can can be calculated. This previously known device

109 747/165

3 4

tion is for the measurement of objects, which passes in cal plane, this plane through a

a long distance past the device - the measuring device penetrating and the course of the

move, not suitable. Vehicle crossing axis 0-0 is determined.

It is also a device for the speed The points used for the measurement can

measurement with a focal plane shutter is known, 5 the most advanced sections of the

by means of a repeated recording of the moving crack of the bow and stern or any other,

Object on one and the same light-sensitive well visible, in which through the ship's axis-

common area is made. Points located in this vertical plane, e.g. B.

are in a closed housing between masts or flagpoles.

the lens and the photosensitive surface io It should be noted that the size of the measured

two times provided with slots and recesses neither of the distance between the driving

Tapes with their ends on two rolls each and the location of the measuring point 3 still from

wraps. The fact that there is a slot and the angle between the vehicle course and the

a larger recess than the slot is dependent on axis 0-0.

can be covered by a relative 15 The accuracy of the

shift of the bands among each other for the light-tuned speed v, which corresponds to the quotient of the

sensitive area different effective slot distance s (between the defined points 1

set the distances. When measuring, the and 2) are divided by the time elapsed from the moment of

both bands, after a suitable passage of point 1 through axis 0-0

Slot spacing was set, with the same amount of 20 up to the moment of passing through point 2

speed on the light-sensitive surface passes through the axis 0-0, corresponds to, depends on

at the same time, so that the object is recorded twice due to the precise knowledge of the two quantities s

will. In addition, after the first up and t.

would take the lens under the influence of a knowledge of the length of the section between

Spring brought into another end position. 25 points 1 and 2, more precisely the pro

When evaluating the recorded images jection same on the horizontal plane, based Due to the known length of the object, must be carried out on the construction drawings of the vehicle a proportional equation of the body in time does not present any particular difficulties actually back between the two recordings and is within the bounds of the error of unplaced Can be calculated. Out of the also 30 dangerously 0.1%.

known time that elapses between the two recordings The problem is thus limited to the precise one, the vehicle speed can then be measured by the second of the factors, ie the time t. determine. Quite apart from the fact that this time could in principle be operated by an observer equipped with a directional stopwatch with a relatively complicated structure and a thoroughly cumbersome operation, but it has the rigid weighting which determines its position, the axis 0-0 Disadvantage that they are measured subjectively for an accurate fixed telescope. A speed measurement is unsuitable because for such a measurement, however, the length of the object could be burdened with a significant ratio calculation and the two photographic recordings measured would primarily be a subjective measurement. It is therefore necessary to do what, because of the small dimensions 40, the measurement of the time t to an accuracy that does not guarantee the maximum of an individual image with sufficient accuracy and the control of the can be carried out. Results as well as the objective estimate of the possible

The invention is concerned with the object of allowing for some degree of error

To create a device that can carry out an objective measurement.

of vehicles and for any development

distances between the vehicle and the device are explained in more detail in the graphical representations. In

is reversible. Fig. 1 is schematically the location of the photo

In a photo camera for objective measurement of the camera 3 and at some distance from the

Speed of moving objects, camera moving watercraft at the start

in particular watercraft, shown with a at 5 ° and at the end of the measurement;

Inside the camera, evenly moving Fig. 2 shows a schematic representation of the photo

and film tape provided with a time scale is the camera according to the invention; in

Invention characterized by a diaphragm with Fig. 3 is the diaphragm with the vertical

a vertical slot through which at An slot and a section of the film tape is shown

adjusting the running speed of the film tape 55;

to the speed of the measurement object an original- Fig. 4 also shows a section of the FiIm-

Faithful image of the measurement object on the ship photographed in the tape with the photograph

The optical path behind the tape and the time scales,

net is. The photographic illustrated in FIG

According to a further feature of the invention, the 60 apparatus consists of an immovable photo line located in front of the vertical slot and of graphic chamber 4 with one in the longitudinal direction a timer controlled lamp for making slidable film tape 6. The chamber is also the time scale on the moving film tape. provided with a corresponding telephoto lens 5.

The determination of the vehicle speed with between the lens 5 and the film tape 6 is

the device according to the invention is based on the 65 there is a diaphragm? which in his

Measurement of the time between the passage of two middle parts a vertical slot 8 of not large

Points 1 and 2 of the hull (Fig. 1) of loading width and length, preferably the width of the film

known mutual distance through a verti- cal, possesses.

Determine the light rays passing through the telephoto lens and falling on the slit the vertical plane through which the axis 0-0 passes.

The vehicle 9 located in front of the lens causes the generation of its reduced and inverted image 10 on the diaphragm 7 with a slit (FIG. 3). Only a narrow vertical section of the image of the vehicle 11 falls on the film tape 6 at the point at which the slot permits. If the vehicle is stationary in front of the lens, the vehicle image is also stationary on the diaphragm. If, however, the vehicle is traveling at a speed v, then the image of the vehicle moving at a _{speed v 0, which is} dependent on the degree of reduction of the image, is located on the diaphragm of the immovable apparatus.

The vehicle subjected to the measurement travels approximately perpendicular to the axis 0-0, but its bow has not yet reached the axis. This location will that be on the diaphragm? on one side of the Slot 8 located and approaching it correspond to the vehicle image. The moment that Image of the front of the vehicle reaches the slot, forms the beginning of the measurement and means that the Vehicle has passed the axle with its bow. At that moment the image of the front of the vehicle falls together with the image of the point 1 determined on it through the slot 8 on the film 6 and is on the same fixed in the form of a strip 11.

Since the film, similar to the vehicle image, moves uniformly and in the same direction at approximately the same speed v _f , the successive fragments of the vehicle image falling onto the film through the slit gradually fix the entire vehicle on it. Before the actual measurement, the film speed is set experimentally so that it roughly coincides with the image migration speed. This is done with HiMe a sighting device on which both the image speed of the passing ship and the adjustable film speed can be seen.

The moment of passage of the rear image through the slot corresponds to the passage of the The rear of the vehicle through the axle, which ends the measurement.

If the film tape contains a time division along its length, then on the basis of the photographic Record the transit time through the axis 0-0 for any point on the vehicle body, therefore also for points 1 and 2.

This division forms, so to speak, a dial that is photographed together with the vehicle and the relationship between each image portion falling on the film through the slit and the Accurately represents time to each other.

The division occurs on the film at the same time as the image of the vehicle. That at certain intervals lighting up light of the lamp 12, which is controlled in the time sequence by an exact clock of the time division 13 denotes the lines of the scale 14 through the same slot 8 on the edge of the film. The time measurement is now limited to determining the distance between points 1 and 2 of the vehicle image on the time scale.

With medium sharpness of the positive and with great accuracy of the clock of the time division, the measured Times can be read with an accuracy of approximately 0.5%.

Claims (2)

PATENT CLAIMS: 1. Photo camera for the objective measurement of the speed of moving objects, especially watercraft, with a film tape moving evenly inside the camera and provided with a time scale, characterized by a diaphragm (7) with a vertical slot (8) through which when adapting the running speed of the film tape to the speed of the test object, a true-to-original image of the test object is recorded on the film tape lying underneath in the beam path. 2. Photo camera according to claim 1, characterized by one arranged in front of the vertical slot (8) and by a timer (13) controlled lamp (12) for producing the time scale (14) on the moving film tape (6). Considered publications: German patent specifications No. 579 052, 667 198. 1 sheet of drawings © 109 747/165 11.61