HU212959B - Position-sensible light barrier - Google Patents

Abstract

The present invention relates to a position sensitive light barrier for measuring athletic jumping performance. The light barrier according to the invention comprises controllable light sources (3) provided on a transmitter support strip (1), the set of which is arranged along a line and similarly arranged light sensor elements (4) mounted on the receiving side rail (2). The outputs of the controllable light sources (3) are connected to the outputs of the light source drive unit (5). The output of the light sensor elements (4) is connected to a signal selection unit (6) input. The output of the light source driver unit (5) and the signal selection unit (6) is connected to the output of a light source selection unit (7). The latter is equipped with a blocking input (11) and a clock generator (8) is connected to the clock input. The output of the signal selection unit (6) directly generates an electrical output (12) of the entire device arrangement by inserting a result storage unit (9) directly or with a wipe input (10). EN 212 959 B Scope of the description: 10 pages (including 4 sheets)

Description

(57) EXTRAS

Field of the Invention The present invention relates to a position-sensitive light barrier for measuring mainly athletic jumping power. The light barrier according to the invention comprises controllable light sources (3) mounted on a transmitter side bar (1), a series of which is arranged along a line and similarly arranged light sensing elements (4) mounted on a receiving side bar (2).

The inputs of the controlled light sources (3) are connected to the outputs of the light source drive unit (5). The outputs of the light sensing elements (4) are connected to the input of a signal selection unit (6). The output of the light source drive unit (5) and the signal selector unit (6) are connected to the output of the light source selection unit (7). The latter is equipped with a blocking input (11) and a clock generator (8) is connected to the clock input. The output of the signal selection unit (6) forms an electrical output (12) of the entire device arrangement either directly or by interposing a result storage unit (9) also provided with an erase input (10).

HU 212 959 B

Description: 10 pages (including 4 pages)

HU 212 959 Β

The present invention relates to a position-sensitive light barrier for measuring mainly athletic performance, especially athletic jumping performance.

It is known that performance in the international forefront of sport is so balanced that differences between them can only be measured using advanced instruments. In some races, the order of rankings is often determined by the time difference of one hundredth of a second. However, in the four jumps of athletics (long, high, triple and pole jumps), the measure of performance is still a centimeter, which means that the resolution of the parameter used to measure performance is quite rough. It would be advisable for the performance to be more precise, e.g. mm could be measured. For high jumps and pole jumps, this would mean that in the case of a valid jump, that is, if the competitor does not beat the jump skip placed in cm steps, it would also be necessary to measure the athlete's passage over the skip.

The situation is more complicated than long jump and triple jump. The jump here is valid if the competitor does not cross the jump line at the start of the jump. However, it would be worthwhile to measure how many millimeters the competitor jumps in front of the jump line. It would also be worthwhile to know how far the competitor is from the jump line before landing on the ground when he or she is passing through a theoretical horizontal plane that is exactly at the level of the jump board that he or she has jumped from. This distance can only be accurately measured if the surface of the sand in the pit is exactly horizontal and its height is exactly the same as that of the platform. However, this requirement in the competition rules is generally not met, but if it were met, it would allow measurement to an accuracy of up to cm.

The object of the present invention is mainly to solve the above problem, that is, to provide a means by which the power of the four athletic jumps can be measured with a resolution of up to mm. This measurement can be solved by creating a light curtain in the vertical plane above the jump bar for high jump and bar jump numbers, e.g. occupies a strip about 10-20 cm upwards from the jump skate along the entire length of the skip. If an object protrudes from above this light curtain, the extent of penetration can be measured, provided that the light barrier is position sensitive, ie its technical solution is capable of detecting and indicating not only the fact of penetration but also the depth of penetration. For long jump numbers, it is advisable to use two such light curtains. One in the form of a 2030 cm wide horizontal bar a few millimeters above the jump board, and the other at the hopper's expected arrival point above the sand, also horizontally about 30 to 100 cm wide at the level of the board. So the required light band for the different jumps is approx

It should be 10-100 cm wide and 3-6 m long. For high-jump numbers, the light bar plane of the position-sensitive barrier is vertical, and for long-range jumps, it is horizontal.

Such a light curtain can be formed by using a light emitting organ at one end of the light bar and a light detecting organ at the other end so that it is not only possible to detect from the signals of the receiving light sensor that the light path is obscured by an object, how much of the path of the light path is covered by the object, and how wide the unobstructed part of that band is from the baseline. Photocell light barriers, which are common in lifts, front doors and other areas, are not relevant as these solutions do not meet the requirements.

In industrial measuring technology, there are several solutions for measuring the position and geometric size, especially diameter, of various workpieces, which accomplish a task similar to the present one, and thus, in principle, could be used to measure athletic performance.

The solution disclosed in EP 0 0157 431, which is a priority of ΓΓ 8 332 384, uses a monochromatic coherent light parallelized on the transmitter side of the photocell. On the receiver side, the parallel beam beam is mapped to an integrated CCD detector array of light detectors using optical optics and the beam power distribution is evaluated by a computer. One of the major drawbacks of this solution for athletic use is its relative slowness. The computer evaluation can take about 0.010.1 seconds. However, in athletics the movement of the human rest at a speed of 10 m / sec is not uncommon, which means a movement of 100 mm or 10 cm in 0.01 sec. This would require a solution in which the response and / or repetition time of the measurements should not exceed 0.001 sec. A further disadvantage of this known solution is that the available light bandwidth is practically no more than 10-20 cm according to the design aspects resulting from the principle of operation.

In this solution, the gap-free modular replication of the detection band is also insoluble.

Laser scanning devices are known for solving a similar type of problem.

GB 2 162 941 discloses a polygon mirror rotating in the focus of a collector lens, the mirror blades of which project the laser beam directed at them to the lens and repeatedly scan it. As the polygon mirror rotates, the beam exiting the other side of the lens moves parallel to itself, thereby repeatedly scanning the light bar of the photocell, where it forms a dynamic light curtain. On the receiving side, the unobstructed light band width or baseline width of the light band can be measured by measuring the length of time the obscuration or obstruction remains. This solution is advantageous in that it is possible to achieve a practically unlimited wide photocell span and to approach the measurement time

HU 212 959 Β

Response time around 0.001 sec. However, the disadvantage of the solution is that it is quite expensive and the available light bandwidth is very limited, in practice about 100-150 mm. A further disadvantage is that modular multiplication of the light bands is also impossible in this solution.

A very noteworthy scanning laser beam photocell solution is found in EP-A-0 245 198, patent number CH 1299/86. In this arrangement, the transmitter-side scanning optics and the receiver-side optics do not consist of lenses, but for this purpose a holographic optical element, called HOE optics, is used. It is nothing more than a holographic patterned glass sheet that acts like an optically corrected lens system due to the interference phenomenon on the slant.

The advantage of this solution is that it provides a much wider scanning light band than the lens optics. However, the disadvantage of the solution is that the production of HOE optics is very costly and the gapless modular replication of the light bands is not possible here.

A further disadvantage of any scanning laser beam solution is that the laser beam can cause eye damage when it reaches the human eye. Therefore, due to accident prevention considerations, only heavily reduced intensity laser beams should be used for athletic measurements, which increases the likelihood of incorrect measurement and / or increases the complexity and cost of the receiver-side signaling and processing system.

The solution described in patent application HU 164 351 is the closest to the present invention. In this case, the light-emitting body consists of a series of light sources, and the light-sensing organ facing it is a series of light-sensing elements. Each light source has a light sensor element. The optical environment of the latter is designed so that each light sensing element detects only the light of the corresponding light source. An electronic digital logic network is connected to the light sensing body, each flip-flop being associated with each light sensing element. The logic network is structured so that the tilt circuits can be reset by pressing a single push button. Then, if part of the light band is obscured, the tilt circles for the obscured part, and for all other light sensing elements away from the baseline, are chain-linked. Therefore, at the end of the obstruction, the position of the tilt circles will be typical of the obscured light path closest to the baseline. The advantage of this solution is, on the one hand, very fast operation and, on the other hand, that the width of the light curtain can in principle be increased by any gap-free modular replication of the light emitting and light sensing organs. The major disadvantage of this solution is the design requirement that each light sensor element should only detect the light of the corresponding opposite light source and be insensitive to the light of adjacent light sources. Due to this requirement, a resolution of less than 1 cm is not achieved with this solution. However, even with a resolution of 1 cm, the apparatus of the solution requires such precise optical adjustment that it causes uncertainty in the position of the light-emitting or light-sensing unit due to its slight inaccuracy, displacement and vibration. A further disadvantage of this solution is that, when a few psec of light is obscured by a single light-sensing element, the device starts to malfunction immediately. Such distractions can occur, for example, in outdoor long jump competitions, where small and short-term distractions can be caused by drizzle rain drops, or by sand particles or dust cloud particles thrown in during a jump.

Our aim is mainly to overcome the disadvantages of the latter solution.

Our goal is to provide a position-sensitive light barrier that has the following advantageous properties:

- have a light bandwidth of at least 200300 mm and a minimum spacing of at least 5 meters,

- the solution should allow for a seamless modular bandwidth extension by placing several devices side by side,

- the solution should allow a resolution of less than cm, if not mm,

- the instrument response time and / or measurement repetition cycle time shall not be greater than 0.001 seconds,

- the device must be insensitive to ambient light and to the obstruction of a single light path for a short time,

- the production costs are moderate.

The basic idea of the present invention is to recognize that if the light sources on the transmitter side of the light barrier, i.e. the light emitting organ, are not continuously lit, but are flashed one after the other, the light sensor for the light source being flashed on the receiving side. By logically selecting its signal, the obstruction of the light path connecting them can be clearly identified. A succession of cyclically repeated flashes of all light sources thus achieves a similar performance. as with scanning laser beam solutions, but the light band may be much wider.

An advantage of the present invention is that, due to the time-multiplex operation, the resolution can in principle be refined as desired, limited only by the physical size of the light sources and light sensing elements. A further advantage is that a logic condition can be easily incorporated into the system operation such that the operation is triggered by the simultaneous obstruction of two or more adjacent light paths or some degree of agreement between the results of two consecutive scan cycles. This eliminates malfunctions due to rain drops or whipped sand. Another advantage of this solution is that since the light sensing elements do not have static illumination

EN 212 959 Β, but responding abruptly so that slowly changing backlight levels do not interfere with the operation of the unit. Interference insensitivity is further enhanced by the fact that each light sensor element is activated for a relatively short period of time during the scan cycle. Therefore, the likelihood of coincidence with pulsed-like interfering optical effects is low.

Another advantage of the solution is that the slight displacement, ejection or vibration of the light emitting organ and / or light sensing organ does not substantially interfere with the operation of the apparatus, since it does not cause any light path to be interrupted.

In addition to athletic performance measurement, the present invention is economically applicable e.g. also for security purposes, intrusion detection, and size control of cargo and workpieces conveyed on roller conveyors or on conveyor belts combined with passage detection.

Accordingly, the present invention relates to a position-sensitive photocell mainly for measuring athletic performance, comprising a light-emitting organ located at one end of the photocell and a photodetector at the opposite end of the photocell. The light-emitting body consists of a series of controllable light sources mounted on a transmitter-side carrier and the light-emitting body consists of a series of light-sensor elements mounted on a receiver-side carrier. The number and pitch of the controllable light sources and the light sensing elements are preferably the same.

SUMMARY OF THE INVENTION The controllable light sources are connected to the inputs of a light source drive unit, the outputs of the light sensing elements are coupled to a signal selection unit input, and the light source drive unit and the signal selector unit input are connected to a light switching unit output, and, the output of the signal selection unit, by interposing a result storage unit with a direct or deletion input, forms the electrical output of the light barrier arrangement of the present invention.

In one of the most preferred embodiments of the position sensitive light barrier device of the present invention, the controllable light sources are infrared LEDs and the light sensing elements are photodiodes. The latter must be chosen so that their maximum spectral sensitivity is as close as possible to the wavelength of the LEDs, and additionally it is advisable to provide them either individually or in groups with narrowband light filters adapted to the wavelength of the LEDs. It is also very advantageous for the light source selection unit to have a blocking input through which its operation can be inhibited by an electrical signal.

An exemplary embodiment of the present invention will be described by way of illustration. On the drawing it is

Figure 1 is a schematic diagram of an optical and electronic arrangement of the present invention;

Figures 2, 3 and 4 illustrate optical conditions during operation.

Fig. 1 shows a series of controllable light sources 3 mounted at one end of the photocell spacer beam on a transmitter side carrier strip, while at the other end of the spacer a series of light sensing elements 4 mounted on a receiver side rail 2. The controllable light sources 3 are connected to the inputs of the light source driver 5. The outputs of the light sensing elements 4 are connected to the input of a signal selection unit 6, the output of the latter forming an electrical output 12 of the arrangement via a result storage unit 9. The result storage unit 9 is equipped with 10 wipe inputs. The output of the light source selection unit 7 is connected to the address inputs of the light source drive unit 5 and the signal selector unit 6, and a clock generator 8 is connected to the latter's clock input. The light source selection unit 7 is also provided with an inhibit input 11.

In Fig. 2, a contour of an object 13 extends from above between the controllable light sources 3 mounted on the transmitter carrier strip and the light sensing elements 4 mounted on the receiver carrier bar and obscures a portion of the parallel rays 14 according to the extent of penetration.

The arrangement shown in Fig. 3 is identical to the arrangement of Fig. 2, but here, by way of example, the beams 14 of light, which touch the contours of the object 13, are shown, not parallel.

The arrangement of Fig. 4 is substantially the same as that of Figs. 2 and 3, with the only difference that now the object 13 shows three distinct shadows in the detection bar of the photocell. This may be due to eg. the concave shape of the object 13, or the possibility that several objects 13 may penetrate the detection band at the same time. In the figure, some beams of light 14 which are directly affecting the contours are shown.

The operation of the optical-electronic arrangement of Figure 1 is described below.

The layout can operate in a variety of modes, depending on the degree of capacity building and programming of each functional component. In the simplest version, the optional result storage unit 9 is not included in the system and the light source selection unit 7 is not provided with a blocking input 11. In this case, the operating program eg. could be:

For each pulse of the stroke generator 8, the light source selection unit 7 moves one step and addresses the first, second, etc., one after the other. 3 controllable light sources, then start this cycle again from the beginning. The address displayed at the output of the light source selection unit 7, which is always the serial number of a controllable light source 3, is transmitted to the signal selection unit 6, which will now monitor the electrical output of the light sensor element 4 corresponding to the address. The same address is transmitted to the light source drive unit 5 which, after a suitable delay, flashes for a brief moment the addressable serial number 3 controlled light source. So if the light source selector 7

The unit selector unit 6 will monitor the signal of the twenty-eighth light sensor element 4 and the light source driver unit 5 will also illuminate the twenty-eighth controllable light source 3. Thus, the sign of the twenty-eighth light sensor plate 4 will indicate whether the line connecting the twenty-eighth controllable light source 3 is obscured, i.e., whether the twenty-eighth parallel light path of Figure 2 is free. Thus, based on the signals of the light sensing elements 4, the output of the signal selection unit 6 can permanently indicate which horizontal light paths are obscured, e.g. the object 13 of Figure 2 covers a portion of the light barrier detection band.

The optional insertion of the result storage unit 9 is particularly useful if the data output is to be compressed by reducing the number of output bits and / or to preserve the trace of a very fast intrusion event and / or not only the depth of the intrusion but also we would like to receive information.

If the purpose is to rely solely on information penetration and, in addition, because of the nature of the task, the intrusion phenomenon of FIG. 2 is required, the result storage unit 9 needs to be constructed with only a single number storage capacity. In this case, the result storage unit 9 is e.g. always the

2 stores the sequence number of the highest, not yet obscured horizontal beam of light 14 as shown in Figure 2, updates this sequence number per cycle, and the output of the most recent refresh cycle is always read from the output.

The situation is different if the intrusion of the type shown in Fig. 2 is only short-term and we want to later identify the coordinate of the deepest intrusion. In this case, the logic circuits of the result storage unit 9 should be constructed so that it also performs the following logical operations in each update cycle:

a) Determine the number of the horizontal ray of 14 which is associated with the current contour point.

b) Compare the sequence number with the sequence number stored in the previous update cycle.

c) If the new sequence number indicates a lower beam of light 14, the stored sequence number is overwritten, otherwise the stored sequence number remains unchanged.

In the case of cyclical repetition of the above sequence of operations, upon completion of the intrusion event, the result storage unit 9 will store the deepest intrusion coordinate and transmit it to the electrical output 12. Of course, before starting another intrusion event, the result storage unit 9 must be reset with the electrical signal applied to the wipe input 10. This is the typical mode of operation that is best suited for performance measurement in athletic jumping. In such a use, a numeric display device, possibly a computer programmed for displaying and administering the results, may need to be connected to the electrical output 12, and preferably a manually operated common push button is preferably attached to the wiper input 10.

A more powerful solution is required to implement both the signal selector unit 6 and the result storage unit 9 if we are interested not only in the depth of penetration but also in the shape and size of the penetrating object 13, especially if the concave object 13 and / or simultaneous penetration of several independent 13 objects. This problem can be solved by identifying the spatial position of the light rays 14 which fit into the contour line of the penetrating object or objects, as illustrated by the examples shown in FIG. 3 and FIG.

In order to identify the position of the light beams 14 associated with the contours, the capacity of the signal selection unit 6 must be constructed by reading out the output signals of all light sensing elements 4 as each serial number controlled light source 3 flashes. The function of the result storage unit 9 is to store the serial numbers of the light sensing elements 4 which define the dark-light boundaries assigned to each sequence number. In this mode of operation, it is not required that the number and / or pitch of the controllable light sources 3 and the light sensing elements 4 be the same, since in this case a computer should be used which is preferably connected online to the electrical output 12.

If the width of the detection bar of the light barrier of the present invention proves to be small for the task, two or more devices can be placed side by side to cover the wider bar. In this case, the blocking inputs 11 of the light source selection unit 7 can be used to prevent the light flashes of the multiple light bars from interfering with each other. Namely, in the case of an electrical signal applied to the blocking input 11, the light source selection unit 7 does not select any serial number, so that during the blocking period all controllable light sources 3 are dark and the output of the signal selection unit 6 remains passive. In this case, for example, the other adjacent photocell may work smoothly. Thus, in the case of multiple photocells, they must be operated in a time-sharing, so-called timesharing mode, by applying a control unit known per se, which allows each photocell to operate cyclically, alternately.

The following aspects should also be taken into account in the practical implementation of each of the functional units shown in Figure 1.

The infrared LED types used in TV remote control units are the most suitable for the 3 controllable light sources, because they are inexpensive due to the very large series production. Their speed and performance are fit for purpose as they have a flash rate in the order of microseconds. Their advantage is also. that the human eye is not harmed. Accordingly, it is desirable to use photodiodes which are employed for the light sensing elements 4

HU 212 959 Β

LED types show maximum sensitivity at the wavelength of radiation and are equipped with a narrow band color filter fitted to the same wavelength. Preferably, the transmitter-side carrier strip and the receiver-side carrier strip 2 are printed circuit boards. The neck, which not only carries the LEDs or the photodiode, but also the light source driver unit 5 and the signal selector unit 6 are incorporated therein.

If the mechanical size of the LEDs or photodiode types used is larger than the resolution to be achieved, a two or more row offset arrangement may be provided. For higher pitch densities, the use of non-enclosed LEDs or photodiode chips, and even integrated LEDs or photodiode sequences, may be considered. In this case, a common screen or a color filter can be used.

The beat generator 8 is a square oscillator known per se, preferably with oscillating quartz frequency stabilization. The light source selection unit 7 may be implemented, for example, as a digital counter in any binary code system. The light source drive unit 5 can be implemented in the form of a series of power switches fitted to the outputs of a digital decoder.

The signal selection unit 6 is e.g. it can be configured to include a preamplifier for each of the 4 light sensing elements, a multi-input and single-output analog demultiplexer, and a comparator circuit. However, the signal selection unit 6 can also be configured such that each light sensor element 4 has a comparator circuit and an appropriate digital logic network is connected to its outputs. In either variation, the design of the signal selection unit 6 based on the functional description detailed above is a routine electrical engineering task. The same applies to the result storage unit 9 consisting exclusively of digital logic circuits.

The resolution of the position-sensitive light barrier of the present invention is not close to that of a scanning laser beam device, often below a micron. However, the present invention has significant advantages in applications requiring coarser resolution. These benefits include:

- a multi-meter span is also available,

- gapless modular replication of photocells is easy,

- simple construction, low cost production, high reliability, mainly due to the lack of moving parts,

- the available operating speed is significantly higher than the known CCD detector and scanning laser beam devices,

- high degree of insensitivity to external disturbances, mounting inaccuracies and orientation instabilities,

- radiation dangerous to the human eye does not occur.

Because of the above-mentioned advantageous properties, the present invention is particularly suitable for use in the open and / or in the human environment and thus may be used in addition to the originally intended athletic performance measurement task. Thus, the position-sensitive light barrier of the present invention is advantageously used to automatically detect the passage and outline size of luggage transmitted on a roller conveyor or conveyor at airports or warehouse material handling systems, passenger counting, burglar alarm and intrusion protection, farm animal movement registration, etc.

Claims (3)

PATENT CLAIMS 1. Position-sensitive photocells, mainly for measuring athletic performance, comprising a light emitting organ located at one end of the photocell ribbon and a photodetector mounted at the other end of the photodevice filament, and a series of light sources mounted on a transducer The light sources and the light sensing elements are preferably of the same number and pitch, characterized in that the light sources are arranged in an electric signal-controlled manner, and these controllable light sources (3) are connected to the outputs of the light source drive unit (5). ) outputs are coupled to the input of a signal selection unit (6), a spinning-off selection unit to the address input of the light source drive unit (5) and the signal selection unit (6) An output of (7) is connected, a clock generator (8) is connected to the input of the latter clock, and the output of the signal selection unit (6) forms an electrical output (12) of the device arrangement either directly or via a result storage unit (9). The position-sensitive light barrier according to claim 1, characterized in that the controllable light sources (3) are infrared LEDs and the light-sensing elements (4) are semiconductor photodiodes having a maximum sensitivity wavelength equal to the radiation wavelength of the controlled light sources (3). and, moreover, are preferably fitted individually or in groups with narrow-band color filters adapted to the emission wavelength of the controllable light sources (3). The position-sensitive photocell according to claim 1 or 2, characterized in that the light source selection unit (7) is also provided with an anti-function inlet (11). HU 212 959 Β Int Cl ⁶ : GOI B 11/00 lobra HU 212 959 Β Int Cl ⁶ : G 01 Β 11/00 Figure 2 HU 212 959 Β Int Cl ⁶ : G 01 Β 11/00