SU1084157A1 - Apparatus for measuring the rotation speed of vehicle wheel pair - Google Patents

Abstract

1. A DEVICE FOR THE DETERMINATION OF THE SPEED OF THE ROTATION OF THE WHEEL-PAIRED VEHICLE, containing a tachogenerator, to the output of which a rectifier is connected and successively connects a single adder, a smoothing filter, a controlled oscillator and a frequency divider, which is used by a set of combos. In order to improve accuracy, it is equipped with an angular acceleration sensor and an analog key, one input of which is connected to the output of the tachogenerator, the other - with the output output sharing the frequencies, and the output - with one of the inputs of the adder, the other and the third inputs ootvetstvenno connected to outputs of the rectifier and angular acceleration sensor. 2. The device according to p. 1, about tl and .4 ayu with the fact that the frequency divider consists of a counter of two logical elements And a trigger, the inputs of which are respectively connected to the outputs of logical elements And, the inputs of which are connected to the outputs the corresponding bits of the counter, (O whose input and trigger output are respectively the input and output of the frequency divider.

Description

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The invention relates to a measurement technique and can be used in devices that detect excessive slip, for example, vehicle wheel pairs.

A device is known for determining the rotational speed of a vehicle's wheel pair, which contains a tachogenerator, to the output of which a rectifier is connected, and subsequently connected an adder, a smoothing filter, a controlled oscillator and a frequency divider ij.

A disadvantage of the known device is the presence of a dynamic error in measurement due to the inertia of the smoothing filter. With high demands on the static accuracy of the device, the time constant of the smoothing filter should be significant, which leads to its increased inertia. As a result, the multiplication of the input frequency occurs with a delay, and in some x a spontaneous change in the multiplication factor may occur.

The aim of the invention is to increase accuracy.

This goal is achieved by the fact that the device is equipped with an angular acceleration sensor and an analog key, one input of which is connected to the output of the tachogenerator, the other - with the output of a frequency divider, and the output - with one of the inputs of the adder, the other and third inputs of which are respectively connected to the outputs of the rectifier and angular acceleration sensor ..

In addition, the frequency divider consists of a counter, two logical elements AND and a trigger, the inputs of which are respectively connected to the outputs of logical elements AND, whose inputs are connected to the outputs of the corresponding bits of the counter, whose input and output of the trigger are respectively the input and output of the divider frequencies.

Figure 1 shows a block diagram of a device for determining the speed of rotation of a vehicle's wheel pair; figure 2 is a functional diagram of the frequency divider.

The device contains a synchronous tachogenerator 1, to the output of which a rectifier 2 is connected, series-connected adder 3, a smoothing filter 4, a controlled generar 5 and a frequency divider, an angular acceleration sensor 7 and an analog switch one input of which is connected to the output of the tacho generator 1, the other with the output of the frequency divider b, and the output with one of the inputs of the adder 3 / the other and the third inputs, of which, respectively, are connected to

The outputs are rectifier 2 and the angular acceleration sensor 7. The frequency divider 6 (FIG. 2) consists of a counter 9, two logical elements 10 and 11 and a trigger 12, the inputs of which are respectively connected to the outputs of the logic elements 10 and 11, whose inputs are connected to the outputs of the corresponding bits of the counter 9 /, whose input and the output of the trigger 12, is respectively the input and output of the frequency divider 6.

A device for determining the rotational speed of a vehicle wheel pair operates as follows.

The synchronous tachogenerator 1 generates a variable signal, the voltage and frequency of which are directly proportional to the angular velocity of the wheelset. Rectifier 2 converts the signal of the tachogenerator 1 into a single line voltage U.

The voltage Uj at the output of the angular acceleration sensor is directly proportional to the magnitude of the angular acceleration of the wheel pair. In adder 3, the voltages U- and U. c1 | Flip signal and U + Vf are added to filter 4, since the average voltage Vg supplied to the first input of cylater 3 from analog key 8, at nominal values of parameters of nodes equals zero. The parameters of the nodes are chosen in such a way that a speed-free speed conversion occurs in voltage 04- at the output of filter 4. The voltage Uj from sensor 7 acts as a correction signal, which, due to U2 f, eliminates the delay in converting the signal from the tachogenerator 1 and eliminate the ding1mic error,

The output voltage U4 converts the controlled oscillator 5 into the frequency f of the output signals, which also go through the feedback circuit consisting of frequency divider 6 and analog switch 8 to the adder 3. The frequency divider b (Fig. 2) works the way that the continuous input to the input of the counter 9 pulses with the frequency fc at the output of the trigger 12 produces pulses with the frequency f, and the duration of the capacitance of the counter is selected

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equal to the desired multiplication factor fk / t

Impulses with divider

arrive at the analog switch 8, at the output of which a signal appears, the duration and form of which corresponds to that part of the signal of tachogenerator 1, which is determined by the pulse duration, At nominal values of the parameters of the nodes, the output pulse is divided; 1B is symmetrical about the moment of signal passage tachogenerator (TOR 1 through zero value, therefore, the average voltage value on the output of the analog key 8 is zero. This state is stable. If the symmetry breaks, this will lead to a change, you the output voltage of the adder 3, and consequently, to a change in the output frequency fgf that, through the feedback circuit, will restore the symmetry of the output signal of the key 8..

Since the duration of a pulse at one input of a key 8 is directly proportional to the signal period of tachogenerator 1, the dependence of the voltage Ug at the output of the key 8 on the phase shift of the voltages on the one and the other is functional. the inputs remain constant over a wide range of amplitude variation of the voltage and frequency f, i.e. over a wide range of variation in wheelset speed.

When deviations from the nominal values of the parameters of the nodes in the device, the set-value of the frequency reduction factor ff / fn t is automatically stabilized, and the average voltage at the output of the switch 8 deviates from the zero value.

Thus, an increase in accuracy is achieved due to the fact that the circuit is changed, frequency multiplication and the use of an angular acceleration sensor, and the signals from the tachogenerator, torus and acceleration sensor are corrective, and the main scrap in the device is analog signal from the output rectifier.

Claims (2)

1. DEVICE FOR DETERMINING THE ROTATION SPEED OF A WHEEL PAIR OF A VEHICLE, comprising a tachogenerator, to the output of which is connected a rectifier and a series-connected adder, a smoothing filter, a controlled generator and a frequency divider, which, in order to increase accuracy, it is equipped with an angular acceleration sensor and an analog key, one input of which is connected to the output of the tachogenerator, the other with. the output of the frequency divider, and the output with one of the inputs of the adder, the other and third inputs of which are respectively connected to the outputs of the rectifier and the angular acceleration sensor. · 2. The device according to claim 1, with the proviso that the frequency divider consists of a counter of two logical elements AND and a trigger, the inputs of which are respectively connected to the outputs of the logical · elements And the inputs of which are connected to the outputs of the corresponding bits of the counter, the input of which and the output of the trigger are respectively the input and output of the frequency divider.