SU1255938A1 - Method and apparatus for measuring velocity of mobile object - Google Patents

Abstract

The invention relates to the telecontrol of mobile objects and can be used in rail track transport. The purpose of the invention is to simplify and reduce the speed measurement error. When moving a moving object in the receiving antenna 3 is induced EMF. The frequency signal in measurement channel 4 is converted to potential. The selector level 5 activates and starts a differentiation unit 6, in which the maxima of the second derivative of the frequency signal envelope are determined. At the time of the occurrence of the maxima of the second derivative, differentiation unit 6 acts on the calculating unit 1, which measures the time interval between the maxima of the second derivative, and then converts it into the velocity value of the moving object. 2 sec. f-ly, 3 ill. with (L JY JV CO 00

Description

The invention relates to the telecontrol of mobile objects and can be applied to rail vehicles.

The aim of the invention is to simplify and reduce the error of the speed meter of a moving object.

FIG. 1 shows the relative position of the transmitting and receiving frame; in fig. 2 - the nature of the signals in the measuring channel; in fig. 3 is a block diagram of a possible implementation of a velocity meter.

The sequence of operations of the method is illustrated in FIG. 2, where in FIG. 2 (a) shows the shape of the envelope E EMF induced in the receiving antenna, in FIG. 2 (b) - the first derivative of the envelope E and in FIG. 2 (c) the second derivative of the envelope E k -function of the distances for some value of h. As follows from FIG. 2, the length of the segment x ,. for a fixed h depends only on the geometric dimensions of the frame antennas, and the speed of movement of the mobile unit is equal to

V S ..,

where (. is the time interval between the arrival of the characteristic maxima of the second derivative of the envelope / E /.

As can be seen from the above ratio, the accuracy of determining v depends only on the geometrical dimensions a, b, h, the accuracy of the measurement of the time interval and does not depend on the scatter of the magnitude of / E / dl for different mobile units caused by the instability of the currents in the antennas and for other reasons. Geometrical dimensions a, b. h can be observed with a high degree of accuracy (fractions of a percent), and, the measurement error taking into account the shape of the maxima E (almost the delta function) and the instability of the time interval sensor (a quartz oscillator) can be reduced to hundredths of a percent.

The device (Fig. 3) contains an excitation generator 1 with a transmitting loop antenna 2, an inductive communication channel, a receiving loop antenna 3 connected to the measuring channel 4 provided on the frequency converter into the potential level selector 5, unit

5 0 5

0

five

0

five

0

five

6 differentiation and scaling block 7, while the output of the receiving antenna 3 is connected to the input of the measuring channel, the output of which is connected to the level selector 5 and differentiation unit 6, the output of the level selector acting on the control input of the differentiation unit which output is connected to the scaling unit 7 .

A device that implements the proposed method works as follows.

When moving a moving object in the receiving antenna 3 is induced EMF. The frequency signal in measurement channel 4 is converted to potential. When the signal reaches the maximum level in the first lobe of the joint antenna pattern. Point m (Fig. 2) triggers the level 5 selector and starts block 6 of differentiation. In the differentiation unit, the maxima of the second derivative of the frequency signal envelope are determined. At the instants of occurrence of the Maxima of the second derivative, the differentiation unit acts on the Enumerator 1, which measures the time interval between the maxima of the second derivative and then recalculates it into the velocity value of the moving object.

Claims (2)

1. A method for measuring the speed of a moving object, consisting in exciting a receiving loop antenna with a frequency signal, transforms. SRI of the frequency signal in the potential, the allocation of the time interval characterizing the speed; : an object, and calculating from an obtained time interval the speed of an object, characterized in that, in order to simplify and reduce the error, the time interval characterizing the speed of the object is separated from the maxima of the second derivative signal of the receiving loop antenna. 2. A device for measuring the speed of a moving object, comprising an excitation generator with a transmitting antenna and a measuring channel consisting of a receiving loop antenna, a frequency signal converter .3 1 to a potential and differentiating unit, characterized in that it is additionally equipped with a level selector and a conversion unit, the output of the receiving antenna being connected through a frequency converter Front frame 2559384 the signal to the potential with the input of the level selector and the differentiation unit, the output of the level selector is connected to the control input of the differentiation unit J, the output of which is connected to the input of the counting unit. FIG. one FIG, g VNIIPI Order 4816/44 Circulation 778 Subscription Proizv.-polygr. pr-tie, Uzhgorod, st. Project, 4