DE1256454B - Electronic device for measuring the speed of moving objects - Google Patents

Description

Electronic device for measuring the speed of moving objects The task of increasing the speed of moving objects between two fixed points measure has been solved in a variety of ways. Mechanical and so-called electromechanical Facilities should not be considered here. On electronic equipment are known the radar speedometers that reflect the time by means of Measure electromagnetic impulses that a moving object moves between two points covered. Timers are also known as counters in which impulses are known the time interval between a start and a stop signal can be counted. A value is displayed or registered here that corresponds to the time that was used during Passing through an object between two fixed points. It is known, by one revolution from the known distance and the measured time, the speed to calculate which is inversely proportional to the time. These facilities require take a certain amount of time to determine the speed and are therefore unsatisfactory. It is also known to use one of the pulses which is proportional to the number of pulses per unit of time Voltage by converting the pulses into an analog value proportional to their number to generate, to feed a measuring instrument with this voltage, which then immediately is calibrated in speed values. There are two flaws in this facility, once the inaccuracy of the reading on a scale limited in length, for others resulting from the function "speed equals distance through time" non-linear scale.

It has also become known, the analog value formed from the pulses to be represented as a resistor which is arranged in a bridge circuit. In a Follow-up control is used to adjust the bridge and the one resulting from the follow-up Value calibrated in speed. There is also a display with a scale here performed. The disadvantages are already mentioned, the time until the speed value can be read is even longer.

It is also known to also have values that are directly digitally available digitally display, e.g. B. As already mentioned, measured times can be used Digitally display counting pulses in a counter. That way you can too Speeds are displayed digitally. Here is an unknown number of pulses counted within a fixed, known time given by an encoder the speed is obtained when the impulses from a speed sensor be delivered.

However, this facility is not designed to measure speed moving objects that are to be measured between two points. It is therefore not possible to use it for the task at hand.

The device according to the invention avoids all of the above Disadvantages and allows a display as quickly as desired after the measurement has been carried out, namely directly the speed, as well as a digital representation of the measured Value in decimal numbers.

The invention is based on an arrangement with two of the continuous Object operated switching devices arranged at a fixed distance from each other and the input of pulses from a frequency generator into an electronic Control digital counting device via a gate circuit and an electronic Use memory for the first count result.

The object is achieved according to the invention in that the Contents of the first memory in a second memory of fixed counting capacity several times is entered and the number of entries to fill the second memory as Digital value of the speed is represented.

So that the speed is displayed immediately in kilometers per hour the pulse frequency It of the generator including a frequency divider, the distance between the switching devices (barriers) and the storage capacity according to the relation s v =. k matched to one another in such a way that the digital numerical value corresponds to the display of the unit kilometers per hour.

The principle of the invention is shown in the figure. In one Generator 1 high accuracy pulses are generated via a line 2 a Gate 3 can be fed. When measuring the speed, the Contacts at measuring points 4 (start) and 5 (stop) closed.

When the contact 4 is closed, the gate 3 is opened, when it is closed from 5 it will be closed. In the time between these two points in time a certain number of pulses is allowed to pass through gate 3 and arrive via line 6 to a frequency divider 7, from there via line 8 to an OR circuit 9 and via line 10 to a pulse counter. In this counter there is one of the runtime the number of pulses proportional to the moving object to be examined, for example 512 saved. After actuation of the contact 5, however, is also via line 12 triggered an interrogator 13. This ensures that the memory 11 via line 14 an AND circuit 15 and a line 16 to a second memory 17 is read out with OR circuit 18 and memory 19, which has a much larger, preferably has 10 times the capacity as memory 11. In memory 17, 19 is now preselected a memory number which, according to the invention, is so large that there is a distance the measuring points and generator frequency as well as the capacity of the memory 11 directly an end display proportional to the speed results. Querying or emptying of the memory 11 takes place until the memory 17, 19 is empty, whereby in the memory 17, 19 is counted backwards. Every time memory 11 is queried once, gets the counter 20 via line 21, switch 22 with position from 23 to 24 and Line 25 a pulse. If you have preselected the number of 1350 in memory l7, 19, so the memory 11, if it is occupied with 512 pulses, so a maximum of twice read out, which would correspond to a speed of 20 km / h if measuring point distance and the frequency of the generator are selected appropriately. Memory 17, 19 is now empty, the preselection of the number 1350 is no longer effective.

That would already explain the principle. In addition, you can do without Survey of the generator frequency and the storage capacity a greater accuracy obtained by expanding the circuit according to the figure, for example, as follows: After the memory 11 has been read out twice with the aid of the interrogation device 13 and thus a number of preselections in the memory reduced by twice the number of pulses 17, 19 and the number of the query in the counter 20 is shown again queried. But now the remaining number in memory 17, 19 is not reached, and after a further 326 pulses result in a pulse that causes the memory 17 to be emptied, 19 indicates. It is taken from line 26.

An auxiliary memory is also provided, which is supplied via line 28 each with the query of the memory 11 was filled. He stands when it appears of the identification pulse on line 26 on the number 326, namely the number that appears after two It is still necessary to enter 512 pulses in memory 17, 19 until they become empty was.

1350-512) = 326.

The impulse appearing on line 26 now calls the following logical Measures: a) The switch 22 is brought to position 23, 30 via line 28 and switches line 21 via switch 22 to line 31 and thus to another Decade 32 to counter 20. b) The auxiliary memory 27 is initiated via line 33 to give a blocking pulse on line 34, which the AND circuit 15 for the further Transmission of pulses from line 14 via 16 is prevented until auxiliary memory 27 is restored is empty. c) The auxiliary memory 27 is simultaneously read out via line 33 after line 35, the OR circuit 18 in the memory 19 causes.

The readout controls the interrogation device via line 36. Memory 18 and 19 were empty or what is the same, on the value O.

Since the pulses stored in the memory 27 are now only available after part 19 of the memory 7, 19 come, after the emptying of the auxiliary memory 27 is the Number 326 in memory 19 or, which is the same, in memory 17, 19 the number 3260.

The auxiliary memory 27 is, after it is empty, now again the Switching 34 for pulses from memory 11 to memory 17 free while over Line 35 no more impulses arrive. The switch 22 remains in position 23-30. The interrogation of the memory 11 with the aid of the interrogation device 13 now begins again. In the memory 17, 19 the number 3260 in it is increased by 521 Pulses decreased until the remainder is less than 521. That gives over the line 21 from the interrogation device 13 to the switch 22 in the course 23-30, line 31 on counter 32 now six pulses.

The number 26 is in the counter 30, 32, corresponding to 26 km / h.

If more pulses get from memory 11 to memory 17, 19, it becomes empty after 3260 - (6 512) = 188 pulses. The control pulse from line 26 now puts everything to a standstill. You can of course with this impulse through a Further switching of the switch 22 to a display unit gain further positions.

Claims (2)

Claims: 1. Arrangement for measuring the speed of a Object in which the object is consecutively two at a fixed distance from each other arranged switching devices operated and this the input of pulses of a Normal frequency generator into an electronic digital counting device via a Control gate circuit and an electronic memory for the counting result is provided is that the content of a first memory is correct (11) is entered several times in a second memory (19) of fixed counting capacity and the number of inputs for filling the second memory (19) as a digital value the speed is displayed. 2. Device according to claim 1, characterized in that the pulse frequency t of the generator (1) including a frequency divider (7), the distance between the two barriers and the capacity k of the memory (19) according to the relationship 8 v = s. k t are coordinated in such a way that the holding digital display indicates the speed directly in kilometers per hour. Considered publications: "AEG-Mitteilungen", 1960, booklet 1/2, pp. 41 to 48; 1961, issue 3/4, pp. 137 to 139; "Electronics" from October 1952, Pp. 158 to 161; Electronic Engineering, February 1958, p. 77.