SU460451A1 - Method of weighing moving objects - Google Patents

Description

one

The invention relates to the field of weighing technology.

Methods are known for weighing moving objects, for example, by integrating a weight sensor signal from the beginning of the first positive half cycle of the low frequency harmonic interference.

These methods do not provide the required accuracy.

The proposed method differs in that, starting from an arbitrary point in time until the end of the measurements, a time interval not less than the period of low-frequency interference remains, at equal intervals of time two consecutive measurements are performed, starting from the beginning of the first half-positive low-frequency noise and end at a predetermined time interval, and select the smallest value from all the measurements made as a result of weighing.

FIG. 1 shows a graph of the output signal of the weight sensor as a function of time; in fig. 2 is a block diagram of a device that allows the described weighing method to be implemented.

Weighing begins at the beginning of the first positive half-period of interference (see Fig. 1) and continues for some period of time (), and, starting with

the time point / i inside the interval (O-AI), up to the time / and at certain intervals of time D /, the measurement results are recorded, i.e. the integrals for different periods of time: from O to / 1, then from O to (i + Aif), etc., and the last dimension from O to c. Of all the results, by successive comparison, occurring in the interval

between adjacent measurements, select the result with the smallest value, which in this case is the most accurate of the total results obtained.

The time interval (/ i-gi) is chosen equal to or greater than the expected period of low-frequency interference.

Presented in FIG. 2 device for implementing the described method contains

the weighing platform 1 with the weight sensor 2 and the pedal 3. The weight sensor 2 through the element "And 4 is connected to the integrator 5, the output of which is connected to the switch 6 connected to the dividing units 7 and 8 connected to the comparison unit 9, the output of which is connected to the switch 10. To the division blocks 7 and 8 is also connected the element "OR 11, the output of which is connected to the elements" And 12, the second input is connected to the control unit 13.

The device works as follows.

When driving over the weighing platform 1 of the object to be weighed from the weight sensor 2 to the element “I 4”, a signal containing information about the weight of the moving object and the low-frequency harmonic interference is received. At the same time, the control unit 13 receives a signal from the pedal 3, and after one of the known methods for starting the first positive half-period of the interference is detected, the control unit 13 outputs the enabling signal to the “AND 4” circuit. After that, the signal from the weight sensor 2 through the “4” circuit goes to the integrator five.

At the moment of time, the signal from the control unit 13 via the switch 6 transfers the contents of the integrator 5 to the division unit 7, in which the average value of the weight is calculated during the time ti. After a time D, a new reading of the contents of integrator 5 (integral value over time (.t), which now goes to division unit 8, where the determination of the average weight per time takes place (i + AO) occurs after the signal from control unit 13 (i + AO) It has both division blocks 7 and 8 in comparison block 9. The latter is designed so that after comparison through switch 10 that division block 7 or 8 is cleared, the result of which turned out to be larger than the other. At the same time, this block 7 or 8 prepares through switch 6to receive new content integrator 5.

These operations are performed in a time Dg between two adjacent readings of the contents of the integrator.

After time 2D / (from the moment of the first reading), the following readings of the integrator contents (the integral value over time (/ 1-г2Дг)), which enters the 7 or 8 division block prepared for reception, occurs.

Then, the remaining and the newly obtained results are compared and the division block 7 or 8 is cleared with a great result.

The described selection of minimum results is made successively until the end of measurement 4g. After completing the measurements, the smallest value of the measured value (weight) will be stored in one of the division blocks 7 or 8, and the other block will be cleared.

Thereafter, the signal from the control unit 13 (the end of the measurements) is transmitted through the element “PLI AND and the element” And 12, the remaining result is sent for further processing or registration.

The accuracy of measurements depends on the number and magnitude of the time intervals between two adjacent measurements, on the number of processed interference periods, and on the accuracy of determining the beginning of a positive half period.

Subject invention

The method of weighing moving objects by integrating a weight sensor signal of the moment of the beginning of the first positive half-cycle of low-frequency harmonic interference, characterized in that, in order to improve accuracy, starting from an arbitrary time when the time interval not less than the period of low-frequency interference remains, no less than the same time intervals are made by successive comparison of two adjacent measurements, starting from the beginning of the first positive half-period of the disturbance, and ending they are with a given time interval, and the smallest value is chosen from all the measurements made as a result of weighing.

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