KR101280031B1 - detection system of conveyor belt split using fourier coefficients - Google Patents

Abstract

The present invention relates to a conveyor rubber belt breakage detection system using a Fourier coefficient, and a transmission module for transmitting an AC signal that can cause an electric induction action to the conductive conductors placed along the driving direction on the conveyor belt, and in the transmission module And a receiving module for detecting a signal transmitted to the conductive wire and determining whether the conveyor belt is damaged by using the AC signal information of the transmitting module from the detected signal. According to the conveyor rubber belt damage detection system using the Fourier coefficient, the detection accuracy of the belt can be improved remotely.

Conveyor belt, breakage, Fourier coefficient

Description

Detection system of conveyor belt split using fourier coefficients

The present invention relates to a conveyor rubber belt breakage detection system using a Fourier coefficient.

Rubber conveyor belts are generally required for the manufacture of carcasses, which are intended to maintain the belt's tensile strength and to support carriers, cover rubbers used to protect them and other belts. It consists of a rubber adhesive. Therefore, because the material is composed of rubber, the conveyor rubber belt is often broken by the raw material.

Conveyor rubber belts are installed over long distances and there is currently no system for monitoring the belts for long periods of wear or damage to the materials during transportation. Therefore, if the conveyor belt is damaged, the raw materials in transit must be temporarily cleaned up, and maintenance work that requires the replacement or maintenance of the rubber belt is required.

In other words, if a belt breaks during logistics using a rubber conveyor belt, a considerable time is required for repairing and repairing the belt as well as the material or cargo being carried on the belt. During this time, the transport of the material must be stopped. In particular, when the belt is broken, the belt is stopped by using an emergency stop switch or other device installed at regular intervals around the conveyor belt in a way that minimizes time problems and costs associated with repair and maintenance.

The present invention was devised to improve the above problems, and an object of the present invention is to provide a conveyor rubber belt breakage detection system capable of remotely detecting whether the belt is broken by inserting an electrically conductive wire into the belt.

In order to achieve the above object, a conveyor rubber belt breakage detection system using a Fourier coefficient according to the present invention is a transmission module for transmitting an AC signal that may cause an electric induction action to a conductive conductor placed along a driving direction on a conveyor belt. and; And a receiving module for detecting a signal transmitted from the transmitting module and induced in the conductive wire, and determining whether the conveyor belt is damaged by using the AC signal information of the transmitting module from the detected signal.

Preferably, the transmission module includes a signal generator for generating a sine wave signal; A first amplifier for amplifying and outputting the sine wave signal generated by the signal generator; And a dense producer for transmitting a signal output from the first amplifier to the conveyor belt, wherein the receiving module comprises: a receiving sensor detecting a signal induced in a conductive wire of the conveyor belt; A first multiplier for multiplying the output signal of the reception sensor and the output signal of the signal generator; A phase shift unit which phase shifts an output signal of the reception sensor; A second multiplier for multiplying the phase shifted signal in the phase shift unit and the output signal of the signal generator; A first low pass filter for low-pass filtering the signal output from the first multiplier; A second low pass filter for low-pass filtering the signal output from the second multiplier; And a processor configured to determine whether the belt is damaged by using the output signals of the first low pass filter and the second low pass filter.

Integrators are preferably applied to the first low pass filter and the second low pass filter, respectively.

According to the conveyor rubber belt damage detection system using the Fourier coefficient according to the present invention, it is possible to remotely detect whether the conveyor belt is damaged, but also to improve the accuracy of detecting the damage of the belt.

Hereinafter, a conveyor rubber belt breakage detection system using a Fourier coefficient according to a preferred embodiment of the present invention with reference to the accompanying drawings will be described in more detail.

1 is a view schematically showing a conveyor belt applied to the present invention, Figure 2 is a block diagram of a sensing system for detecting whether the conveyor belt of Figure 1 is damaged.

1 and 2, the sensing system includes a conveyor belt 10, a transmission module 20, and a reception module 30.

The conductive belt 15 is implanted in the conveyor belt 10 along the traveling direction.

The transmission module 20 is installed to be spaced apart from the conveyor belt 10 and transmits an exchange signal in which an electric induction action may occur to the conductive conductor 15 implanted along the running direction of the conveyor belt 10.

The transmission module 20 includes a signal generator 21, a first amplifier 23, and a transducer 25.

The signal generator 21 generates and outputs a sine wave signal.

The first amplifier 23 amplifies and outputs the sine wave signal generated by the signal generator 21.

The transducer 25 is installed below the conveyor belt 10 and transmits a signal output from the first amplifier 23 to the conveyor belt 10.

The reception module 30 detects a signal transmitted from the transmission module 20 through the transducer 25 and induced in the conductive wire 15, and converts the AC signal information generated by the transmission module 20 from the detected signal. It is to determine whether or not the conveyor belt 10 is damaged.

The reception module 30 includes a reception sensor 31, a second amplifier 33, a band pass filter 35, a first multiplier 41, a second multiplier 42, a phase shifter 37, and a first An integrator 43, a second integrator 44, and a processor 45 are provided.

The reception sensor 31 remotely detects a signal induced by the conductive wire 15 of the conveyor belt 10.

The second amplifier 33 is for amplifying when the signal output from the reception sensor 31 is weak.

The band pass filter 35 is applied to remove high frequency noise components, and may be applied to output a signal of a band corresponding to the frequency of the AC signal generated by the signal generator 21.

The first multiplier 41 multiplies the output signal of the reception sensor 31 through the band pass filter 35 and the output signal of the signal generator 21 to output the multiplier.

The phase shift unit 37 phase shifts the output signal of the reception sensor 31 through the band pass filter 35 by 90 degrees and outputs it.

The second multiplier 42 multiplies the signal shifted in phase by the phase shift unit 37 and the output signal of the signal generator 21 to output the multiplier.

The first integrator 43 is applied as a first low pass filter for low pass filtering the signal output from the first multiplier 41.

The second integrator 44 is applied as a second low pass filter for low pass filtering the signal output from the second multiplier 42.

The processor 45 determines whether the belt 10 is damaged by using the output signal of the first integrator 43 applied as the first low pass filter and the output signal of the second integrator 44 applied as the second low pass filter. Judgment process.

Preferably, the processor 45 adds the output signals of the first and integrators 43 and 44 to the belt 10 when the threshold value is lower than the threshold value which is set to about 1/2 of the normal output value when it is not damaged. ) Is judged to be broken, and if it is higher than the threshold, it is constructed to judge normal.

Such a monitoring system generates a high frequency-to-power signal that can generate an electric induction phenomenon in the conductive wire 15 installed in the belt 10 to be wirelessly transmitted through the transducer 25, and in the receiving module 30, A small signal induced by the conductive wire 15 installed in the belt 10 may be detected by the reception sensor 31, and amplified to detect breakage of the belt 10 according to the presence or absence of a signal.

Hereinafter, a sensing method using Fourier coefficients in such a sensing system will be further described.

하고 이 파형이 지연 소자 또는 임의의 채널을 통하여 전송할 경우

의 위상 지연을 갖는다고 하자. 그러면, 수신센서(31)를 통해 수신되어 출력되는 신호

는 채널을 통하면서 진폭 감쇠가 발생하고 위상 지연이 생긴다. 따라서

가 되며,

가 된다. 위의 두 함수를 이용하여

와

를 구하면 아래의 수학식 1 및 2와 같다.The waveform of the signal generator 21 for generating a sine wave of the transmission module 20

The waveform is transmitted through a delay element or any channel,

Assume that it has a phase delay of. Then, the signal received and output through the receiving sensor 31

Through the channel, amplitude attenuation occurs and phase delay occurs. therefore

Respectively,

. Using the two functions above

Wow

Is obtained as shown in Equations 1 and 2 below.

나

의 신호가 입력되지 않거나

이외의 다른 주파수를 갖는 신호가 입력되면 0이 된다. 따라서 이를 벨트(10)의 파손에 따른 신호의 유무에 적용할 수 있다.Accordingly, the output of the multiplied or modulated signal of the two functions represented by Equations 1 and 2 changes according to the cosine value of the frequency and phase difference of twice. Therefore, when the modulated signal, which is the product of the two signals, is passed using a low pass filter that can remove twice the frequency, information about the phase difference can be obtained. And

I

No signal from

If a signal with a frequency other than this is input, it becomes zero. Therefore, this can be applied to the presence or absence of a signal due to breakage of the belt 10.

Experimental Example

만큼 천이시켜야 하고, 이를 위해 연산 증폭기를 이용하여 다음과 같은 전달함수 특성을 갖도록 설계하였다.First, with respect to the phase shift unit 37,

To do this, the op amp is designed to have the following transfer function characteristics.

At this time, the phase shift is expressed by Equation 4 below.

로 주어지기 때문에 천이시키고자하는 주파수가 결정되면 이 주파수에 따른

과

를 결정할 수 있다. here

Given this, if the frequency to be shifted is determined,

and

Can be determined.

On the other hand, the power amplifier for supplying sufficient power to the transducer 25 using the signal generated by the signal generator 21 generating the sine wave as the first amplifier 23 may use a power amplifier using a linear circuit. However, considering the problem of price and circuit design, a method of amplifying the power may be advantageous in a switching method using a power device, and an example of the first amplifier 23 considering this point is illustrated in FIG. 3. have.

Referring to FIG. 3, two one-shot multivibrators are used to set the dead-time of each switching element of a full bridge driving the transducer 25. The duty ratio was adjusted, the transformer was driven using the NPN Darlington transistor (Tr), and each switching element of the full bridge (NPN Darlington Tr) was used using the output of the transformer. Was driven.

On the other hand, the reception sensor 31 was designed in a similar manner to the transducer 25 on the transmission side, and applied a winding of 1300 [turn] of a winding having a diameter of 0.4 (φ) to the ferrite core.

In addition, the signal output from the transducer 25 is induced in the conducting wire 15 and then induced as an electrical signal to the receiving sensor 31, and the induced signal is 50 [kHz] by using the bandpass filter 35. Only the signal having the band characteristic was extracted, and the signal was shifted in the manner shown in FIG. 2 and then multiplied with the signal input to the transducer 25 and passed through the low pass filter to obtain only information on the phase difference. This signal contains only the low-pass signal of the phase difference, but also has a negative value. Therefore, the absolute value amplifier is used to convert the signal into a positive value. The sum of these two converted signals is constant regardless of the phase difference.

For transmission, first, a transformer is driven using a NPN Darlington Tr with a sine wave, and then each switching element (NPN Darlington Tr) of the Full-Bridge is driven using the output of the transformer. The frequency response of the receiving sensor was measured to determine the center frequency for driving the amplifier circuit. Since the measured center frequency has the maximum response at 10 [kHz] and 50 [kHz], the driving frequency was determined to be 50 [kHz]. In order to achieve resonance, the transmitter was connected in series with a capacitor to drive the transmission transducer.

The transducer 25 wound a coil having a diameter of 0.4 [mm] on a ferrite core, and the number of windings was 1300. The results of the measurement with an Agilent 4263B LCR meter are shown in Table 1. Measurement conditions are 1000 [mV] and 1 [kHz].

Table 1. Electrical Characteristics of Receive Sensor

Equivalent Power L Equivalent series C Resistance component 297.33 [mH] -85.16 [nF] 22.8 [Ω] Reactance Impedance Size Impedance Angle 1867.0 [Ω] 1867 89.30

The system used Fourier coefficients as a parameter for detecting belt breakage as described above. Since Fourier coefficients have an effect on the phase difference of each signal, the Fourier coefficients are obtained by directly or phase shifting the received signal. By doing in this way, the magnitude | size of the coefficient which arises because of a phase difference does not change and maintains a constant value. And in order to remove the mixed noise of the signal at the receiver side, only the signal which affects the breakage of the belt can be extracted by using the active band and the low pass filter. In this way, when the belt is broken, it can be seen that the detection by the breakage is made correctly.

1 is a view schematically showing a conveyor belt applied to the present invention,

2 is a block diagram of a detection system for detecting whether the conveyor belt of FIG.

3 is a circuit diagram illustrating an example of the first amplifier of FIG. 2.

Claims (3)

delete delete A transmitting module for transmitting an alternating current (AC) signal in which an electric induction action may occur to a conductive conductor placed on the conveyor belt in a continuous connection state along the running direction; And a receiving module for detecting a signal transmitted from the transmitting module and induced in the conductive wire, and determining whether the conveyor belt is damaged by using the AC signal information of the transmitting module from the detected signal. The transmission module A signal generator for generating a sine wave signal; A first amplifier for amplifying and outputting the sine wave signal generated by the signal generator; And a dense producer for transmitting a signal output from the first amplifier to the conveyor belt. The receiving module A reception sensor for detecting a signal induced in a conductive wire of the conveyor belt; A first multiplier for multiplying the output signal of the reception sensor and the output signal of the signal generator; A phase shift unit which phase shifts an output signal of the reception sensor; A second multiplier for multiplying the phase shifted signal in the phase shift unit and the output signal of the signal generator; A first low pass filter for low-pass filtering the signal output from the first multiplier; A second low pass filter for low-pass filtering the signal output from the second multiplier; And a processor configured to determine whether the belt is damaged by using the output signals of the first low pass filter and the second low pass filter. Conveyor rubber belt breakage detection system, characterized in that the integrator is applied to each of the first low pass filter and the second low pass filter.

Images