TWI812410B - Method for monitoring conveyor belt - Google Patents

Abstract

Method for monitoring a conveyor belt includes the following steps. A f first vibration signal of a first side of the conveyor belt and a second vibration signal of a second side of the conveyor belt are obtained. The first and second vibration signals are utilized to determine whether the conveyor belt is in running or stopped state. When the conveyor belt is in the running state, the first and second vibration signals are utilized to determine whether the conveyor belt is loaded with or without material. When the conveyor belt is in the running state and loaded with material, a first back-tape temperature the first side and a second back-tape temperature of the second side are obtained, so that the first and second vibration signals, and the first and second back-tape temperatures are utilized to determine whether one side of the conveyor belt is skewed and abnormally high temperature.

Description

Monitoring methods for conveyor belts

The present invention relates to a monitoring method, and in particular to a monitoring method for a conveyor belt.

There are many reasons for fires due to high temperature on conveyor belts, such as insufficient lubrication of rotating parts, careless hot work, weather, equipment aging, conveyor belt/roller wear causing deflection, blanking material accumulation and other multiple factors. If only a single detection method or technology is used, it is often impossible to effectively detect potential abnormal high temperatures and prevent fires in the bud.

Looking back at the past, the methods to prevent conveyor belt fires were to detect the flame/smoke components produced when the conveyor belt burns, the cutting-off mechanism of hot-wire thermal conductivity detectors, fire sprinkler nozzle sensing, or thermal imaging. Device to suppress or extinguish the fire to prevent the conveyor belt from continuing to burn and causing greater losses.

According to the scenarios of past accidents, if there is a high temperature source during the operation of the conveyor belt, the belt will continue to be heated. However, if the conveyor belt is still in operation, the temperature of the conveyor belt will be effectively dispersed, although the conveyor belt itself will generate a certain degree of temperature. liters, but conveyor belt burning accidents are less likely to occur. At the same time, based on past experience, there is a high probability that the high temperature source is caused from one side and then extends to the entire conveyor belt. Specifically, the deflection of the conveyor belt may not only cause poor raw material transportation efficiency, but also be one of the potential main causes of fires. In addition, severe deflection will directly trigger the emergency stop switch of the conveyor, causing the production line to shut down unexpectedly. Therefore, how to conduct real-time monitoring of deviations or high temperature abnormalities in the conveyor belt's operating status is a matter of concern to those skilled in the field.

The object of the present invention is to provide a method for monitoring a conveyor belt, which includes: obtaining a first vibration signal on the first side of the conveyor belt and a second vibration signal on the second side of the conveyor belt, wherein the first side and the second side are Opposite each other in the first direction, where the conveyor belt is transported in a second direction perpendicular to the first direction; according to the first vibration signal and the second vibration signal, it is determined whether the conveyor belt is starting or stopped; when it is determined that the conveyor belt is starting , based on the first vibration signal and the second vibration signal, determine whether the conveyor belt is carrying material or is empty; and when it is determined that the conveyor belt is starting to operate and is carrying material, obtain the first adhesive temperature of the first side of the conveyor belt and the second adhesive temperature on the second side of the conveyor belt. Based on the first vibration signal, the second vibration signal, the first adhesive temperature and the second adhesive temperature, it is determined whether the conveyor belt has unilateral deflection and whether the conveyor belt has unilateral deflection. Extremely high temperatures.

In some embodiments, the above-mentioned monitoring method of the conveyor belt further includes: using two sets of three-axis accelerometers respectively provided on the first side and the second side of the conveyor belt to obtain the first vibration signal of the first side of the conveyor belt. and the second vibration signal on the second side; and using two sets of wireless temperature detectors respectively provided on the first side and the second side of the conveyor belt to obtain the first adhesive temperature and the second back glue temperature on the first side of the conveyor belt. The second adhesive temperature on the side.

In some embodiments, the above-mentioned monitoring method of the conveyor belt further includes: obtaining a third vibration signal of the first side and a fourth vibration signal of the second side of the conveyor belt at a previous time point; At the current time point, obtain the first vibration signal on the first side of the conveyor belt and the second vibration signal on the second side; and determine the conveyor belt based on the first vibration signal, the second vibration signal, the third vibration signal and the fourth vibration signal. It is running or stopped at the current time.

In some embodiments, each of the first vibration signal, the second vibration signal, the third vibration signal and the fourth vibration signal is a three-axis vibration value. The first vibration signal of the current time point i on the first side of the conveyor belt is represented by (A _x1i ,A _y1i ,A _z1i ), and the second vibration signal of the current time point i on the second side of the conveyor belt is represented by (A _x2i ,A _y2i ,A _z2i ) means that the third vibration signal of the previous time point (i-1) on the first side of the conveyor belt is expressed as (A _x1(i-1) ,A _y1(i-1) ,A _z1(i-1) ) means that the fourth vibration signal of the previous time point (i-1) on the second side of the conveyor belt is represented by (A _x2(i-1) , A _y2(i-1) , A _z2(i-1 ). The above The monitoring method of the conveyor belt further includes: subtracting the third vibration signal from the first vibration signal and performing the following calculation, (A _x1i -A _x1(i-1) )+(A _y1i -A _y1(i-1) )+(A _z1i -A _z1(i-1) ) to obtain the first vibration change amplitude of the first side of the conveyor belt between the previous time point and the current time point; subtract the fourth vibration signal from the second vibration signal And perform the following formula calculation, (A _x2i -A _x2(i-1) )+(A _y2i -A _y2(i-1) )+(A _z2i -A _z2(i-1) ) to obtain the conveyor belt The second vibration change amplitude of the second side between the previous time point and the current time point; and when the absolute value of any one of the first vibration change amplitude and the second vibration change amplitude is greater than the first threshold, it is determined The conveyor belt is running at the current time.

In some embodiments, the above-mentioned monitoring method of the conveyor belt further includes: when neither the absolute value of the first vibration change amplitude nor the absolute value of the second vibration change amplitude is greater than the first threshold, it is determined that the conveyor belt is in The current time point is in a stopped state; when the absolute value of either the first vibration change amplitude and the second vibration change amplitude is greater than the second threshold, it is determined that the conveyor belt is started and is carrying materials at the current time point, where The second threshold is greater than the first threshold; and when the absolute value of either the first vibration change amplitude and the second vibration change amplitude is greater than the first threshold but not greater than the second threshold, the conveyor belt is determined to be At the current point in time, the operation is started and there is no material and no load.

In some embodiments, the above-mentioned monitoring method of the conveyor belt further includes: using an upper wireless temperature detector located above the conveyor belt to obtain the ambient temperature at the current point in time and the raw material temperature of the raw materials on the conveyor belt; when the first When either the back glue temperature or the second back glue temperature is greater than the raw material temperature and greater than the ambient temperature, the following formula is calculated for the first vibration signal and the second vibration signal of the conveyor belt at the current time point i, (A _x1i + A _y1i +A _z1i )-(A _x2i +A _y2i +A _z2i ) to obtain the deflection detection amount of the conveyor belt at the current point in time; and when the absolute value of the deflection detection amount is greater than or equal to the third threshold , then it is determined that the conveyor belt has unilateral deflection and abnormal high temperature on one side at the current point in time.

In some embodiments, the above-mentioned monitoring method of the conveyor belt further includes: when the deflection detection amount is greater than or equal to 0 and greater than or equal to the third threshold, then determining that the first side of the conveyor belt is unilateral at the current time point. Deflection occurs unilaterally Abnormally high temperature; and when the deflection detection amount is less than or equal to 0 and the absolute value of the deflection detection amount is greater than or equal to the third threshold, it is determined that the second side of the conveyor belt is unilaterally deflected at the current point in time and A unilateral abnormal high temperature occurs.

In some embodiments, the above-described conveyor belt monitoring method further includes: when the absolute value of the deflection detection amount is less than a third threshold, it is determined that the conveyor belt has not unilaterally deflected at the current time point; When the belt does not deflect on one side at the current time point, the weighted moving average algorithm is used to estimate the fifth adhesive temperature on the first side of the conveyor belt at the next time point immediately after the current time point and estimate The sixth adhesive temperature of the second side of the conveyor belt at the next time point; and predicting whether a temperature rise abnormality will occur on the conveyor belt at the next time point based on the fifth adhesive temperature and the sixth adhesive temperature.

In some embodiments, the fifth back glue temperature is represented by the following formula, W ₁ T _bt1i +W ₂ T _bt1(i-1) +W ₃ T _bt1(i-2) +W ₄ T _bt1(i-3) +W ₅ T _bt1(i-4) , where W ₁ , W ₂ , W ₃ , W ₄ , and W ₅ are weight values and W ₁ >W ₂ >W ₃ >W ₄ >W ₅ , where T _bt1i is the transport The first adhesive temperature of the first side of the conveyor belt at the current time point i, where T _{bt1 (i-1)} is the adhesive temperature of the previous time point (i-1) of the first side of the conveyor belt, where T _{bt1 (i- 2)} is the adhesive temperature at one time point before the previous time point on the first side of the conveyor belt, where T _{bt1 (i-3)} is the adhesive temperature at two time points before the previous time point on the first side of the conveyor belt, where T _{bt1 ( i-4)} is the adhesive temperature at three time points before the previous time point on the first side of the conveyor belt. The above-mentioned sixth adhesive temperature is expressed by the following formula, W ₁ T _bt2i +W ₂ T _bt2(i-1) +W ₃ T _bt2(i-2) +W ₄ T _bt2(i-3) +W ₅ T _{bt2( i-4)} , where T _bt2i is the second adhesive temperature at the current time point i on the second side of the conveyor belt, where T _bt2(i-1) is the temperature of the previous time point (i-1) on the second side of the conveyor belt. Back glue temperature, where T _bt2(i-2) is the temperature of the back glue one time point before the previous time point on the second side of the conveyor belt, where T _bt2(i-3) is two times before the previous time point on the second side of the conveyor belt The adhesive temperature at the time point, where T _{bt2 (i-4)} is the adhesive temperature at three time points before the previous time point on the second side of the conveyor belt.

In some embodiments, the above-mentioned monitoring method of the conveyor belt further includes: when it is determined that the conveyor belt is in a stopped state, using a weighted moving average algorithm to estimate the conveyor belt at the next time point immediately after the current time point. The adhesive temperature on one side is estimated to be the adhesive temperature on the second side of the conveyor belt at the next point in time, thereby predicting whether a temperature rise abnormality will occur in the stopped conveyor belt at the next point in time.

In some embodiments, the above-mentioned monitoring method of the conveyor belt further includes: when it is determined that the conveyor belt is running and has no material or load, using a weighted moving average algorithm to predict the next time point immediately after the current time point. The temperature of the adhesive on the first side of the conveyor belt is estimated at the next point in time, so as to predict whether the conveyor belt will be warm at the next point in time when it is started and has no material or load. Exception.

In order to make the above-mentioned features and advantages of the present invention more obvious and easy to understand, embodiments are given below and described in detail with reference to the accompanying drawings.

122,124: Three-axis accelerometer

142,144,146:Wireless thermometer

200,220: Conveyor belt

300:Roller

400:Raw materials

D1: first direction

D2: second direction

S1-S10: Steps

The aspect of the present invention can be better understood from the following detailed description combined with the accompanying drawings. It should be noted that, in accordance with standard industry practice, features are not drawn to scale. In fact, to make the discussion clearer, The size of each feature can be increased or decreased as desired.

[Fig. 1] is a schematic diagram of component layout of a conveyor belt monitoring technology according to an embodiment of the present invention.

[Fig. 2] is a flowchart of a conveyor belt monitoring method according to an embodiment of the present invention.

Embodiments of the present invention are discussed in detail below. It is to be appreciated, however, that the embodiments provide many applicable concepts that can be embodied in a wide variety of specific contexts. The embodiments discussed and disclosed are for illustration only and are not intended to limit the scope of the invention. The terms "first", "second", ..., etc. used in this article do not specifically refer to the order or order, but are only used to distinguish components or operations described with the same technical terms.

The invention relates to a monitoring technology for conveyor belts. FIG. 1 is a schematic diagram of component layout of a conveyor belt monitoring technology according to an embodiment of the present invention. What is shown in FIG. 1 is a front view. The conveyor belt 200 is driven by the rollers 300 to be conveyed in a direction parallel to the second direction D2, wherein the conveying direction of the upper half of the conveyor belt 200 in Figure 1 is opposite to the conveying direction of the lower half of the conveyor belt 220 in Figure 1 Direction, for example, if the conveying direction of the conveyor belt 200 in the upper half of FIG. 1 is the direction that goes out of the drawing, then the conveying direction of the conveyor belt 220 in the lower half of FIG. 1 is the direction that goes into the drawing. It should be noted that the following statements in this article are all described with respect to the upper half of the conveyor belt 200 in FIG. 1 .

The conveyor belt 200 of the present invention is used to transport raw materials. For example, the conveyor belt can be a coal conveyor belt used for coal mine transportation, or, The conveyor belt can also be, for example, an iron conveyor belt, and the present invention does not limit the application of the conveyor belt.

In the present invention, a wireless temperature detector and a three-axis accelerometer are respectively provided on opposite sides of the back of the conveyor belt 200 . As shown in FIG. 1 , the present invention provides a wireless temperature detector 142 and a three-axis accelerometer 122 on the first side of the conveyor belt 200 (ie, the left side in FIG. 1 ), and the present invention sets a wireless temperature detector 142 on the second side of the conveyor belt 200 (ie, the left side in FIG. 1), a wireless temperature detector 144 and a three-axis accelerometer 124 are provided. The first side and the second side are opposite to each other in a direction parallel to the first direction D1, and the first direction D1 is perpendicular to the second direction D2.

The present invention uses wireless temperature detectors (i.e., wireless temperature detectors 142 and 144) to obtain the surface temperature of the adhesive backing of the conveyor belt 200 in a non-contact manner. In the embodiment of the present invention, the wireless temperature detector is, for example, an infrared detector. Thermostat. The present invention will also utilize a three-axis accelerometer (ie, the three-axis accelerometer 122, 124) fixed on the bracket of the roller 300 for driving the conveyor belt 200 to obtain the vibration measurement function of the conveyor belt 200. vibration signal.

Specifically, the present invention uses the wireless temperature detector 142 to obtain the glue temperature on the first side of the conveyor belt 200, and uses the wireless temperature detector 144 to obtain the glue temperature on the second side of the conveyor belt 200. Specifically, the present invention uses the three-axis accelerometer 122 to obtain the vibration signal on the first side of the conveyor belt 200 , and uses the three-axis accelerometer 124 to obtain the vibration signal on the second side of the conveyor belt 200 .

FIG. 2 is a flow chart of a monitoring method of the conveyor belt 200 according to an embodiment of the present invention. In step S1, the three-axis accelerometer 122 provided on the first side of the conveyor belt 200 is used to obtain the first vibration of the first side of the conveyor belt 200. The vibration signal is obtained, and the three-axis accelerometer 124 provided on the second side of the conveyor belt 200 is used to obtain the second vibration signal of the second side of the conveyor belt 200 . The details of step S1 are stated below. First, at a previous time point, the third vibration signal of the first side of the conveyor belt 200 and the fourth vibration signal of the second side of the conveyor belt 200 are obtained. Then, at a current time point immediately after the previous time point, the first vibration signal of the first side of the conveyor belt 200 and the second vibration signal of the second side of the conveyor belt 200 are obtained. In step S2, it is determined whether the conveyor belt 200 is running or stopped at the current time point based on the first vibration signal, the second vibration signal, the third vibration signal and the fourth vibration signal. In step S3, when it is determined that the conveyor belt 200 is running, it is determined based on the first vibration signal, the second vibration signal, the third vibration signal and the fourth vibration signal whether the conveyor belt 200 is carrying material or is empty at the current time point. In step S4, the wireless temperature detector 146 (also known as the upper wireless temperature detector) provided above the conveyor belt 200 is used to obtain the ambient temperature and the temperature of the raw material 400 (such as coal or iron, etc.) on the conveyor belt 200. Raw material temperature. In step S5, the wireless temperature detector 142 provided on the first side of the conveyor belt 200 is used to obtain the first adhesive temperature on the first side of the conveyor belt 200, and the wireless temperature detector 142 provided on the second side of the conveyor belt 200 is used. The thermometer 144 is used to obtain the second adhesive temperature on the second side of the conveyor belt 200 . In step S6, when it is determined that the conveyor belt 200 is started and is carrying materials, it is determined whether the conveyor belt 200 is unilaterally deflected based on the first vibration signal, the second vibration signal, the first adhesive temperature and the second adhesive temperature. It is tilted and abnormal high temperature occurs on one side. In step S7, when it is determined that the conveyor belt 200 is unilaterally deflected and an abnormally high temperature occurs on one side, a corresponding alarm is issued (for example, a fire extinguishing system is used to implement automatic water spray cooling to achieve Predict the occurrence of conveyor belt fires in advance and prevent fire accidents before they occur). In step S8, when it is determined that the conveyor belt 200 does not deflect on one side, temperature rise abnormality detection is performed. In step S9, when it is determined that the conveyor belt 200 is in a stopped state, stationary temperature rise detection is performed. In step S10, when it is determined that the conveyor belt 200 is started and has no material and no load, no-load temperature rise detection is performed. Other steps can also be added before, after, and between each step of the process in Figure 2 . Each step in Figure 2 can be implemented using computers (such as personal computers, industrial computers, embedded computers, etc.), circuits (such as programmable logic controllers, embedded circuits, etc.) or computerized software. This disclosure is not limited thereto. .

Among them, the details of step S1 and step S2 are as follows. First, at a previous time point, the third vibration signal of the first side of the conveyor belt 200 and the fourth vibration signal of the second side of the conveyor belt 200 are obtained. Then, at a current time point immediately after the previous time point, the first vibration signal of the first side of the conveyor belt 200 and the second vibration signal of the second side of the conveyor belt 200 are obtained. Then, based on the first vibration signal, the second vibration signal, the third vibration signal and the fourth vibration signal, it is determined whether the conveyor belt 200 is in a running or stopped state at the current time point.

In an embodiment of the present invention, each of the above-mentioned first vibration signal, second vibration signal, third vibration signal and fourth vibration signal is a three-axis (i.e. x-axis, y-axis, z-axis) vibration value. . The first vibration signal of the current time point (represented by i in this article) of the first side of the conveyor belt 200 is represented by (A _x1i , A _y1i , A _z1i ) in this article, and the current time point i of the second side of the conveyor belt 200 The second vibration signal of is represented by (A _x2i , A _y2i , _Az2i ) in this article, and the third vibration signal of the previous time point (represented by (i-1) in this article) of the first side of the conveyor belt 200 is represented by (i-1) in this article. represented by (A _x1(i-1) ,A _y1(i-1) ,A _z1(i-1) ), the fourth vibration signal of the previous time point (i-1) on the second side of the conveyor belt 200 is at This article is represented by (A _x2(i-1) , A _y2(i-1) , A _z2(i-1 ).

The details of determining whether the conveyor belt 200 is running or stopped at the current point in step S2 are as follows. For the first side of the conveyor belt 200, subtract the third vibration signal from the above-mentioned first vibration signal and perform the calculation of the following formula (1): A _{( p - p ) 1} = ( A _{x 1 i} - A _{x 1 ( i -1)} ) + ( A _{y 1 i} - A _{y 1 ( i -1)} ) + ( A _{z 1 i} - A _{z 1 ( i -1)} ) (1) to obtain the first side of the conveyor belt 200 The first vibration change amplitude A _(pp)1 between the previous time point (i-1) and the current time point i. In addition, for the second side of the conveyor belt 200, subtract the fourth vibration signal from the above-mentioned second vibration signal and perform the calculation of the following formula (2): A _{( p - p ) 2} = ( A _{x 2 i} - A _{x 2( i -1)} )+( A _{y 2 i} - A _{y 2( i -1)} )+( A _{z 2 i} - A _{z 2( i -1)} ) (2) to obtain the conveyor belt 200 The second vibration change amplitude A _(pp)2 between the previous time point (i-1) and the current time point i. Finally, when the absolute value of either the first vibration change amplitude A _{(pp) 1} or the second vibration change amplitude A _{(pp) 2} is greater than the first threshold, it is determined that the conveyor belt 200 is started at the current point in time. operation.

Specifically, the present invention uses the vibration signal at the previous time point and the vibration signal at the current time point to perform calculations and compares the calculation result with a first threshold value to determine the start and stop status of the conveyor belt 200. The first threshold value can be the operator The empirical value or the reference value calculated based on historical data. In other words, the present invention detects the start and stop status of the conveyor belt 200 through the three-axis vibration measurement function of the three-axis accelerometers 122 and 124 in steps S1 and S2.

Next, in step S3, when it is determined that the conveyor belt 200 is running at the current time point, it is further determined based on the first vibration signal, the second vibration signal, the third vibration signal and the fourth vibration signal that the conveyor belt 200 is carrying material at the current time point. Or no material or load. The details of determining whether the conveyor belt 200 is loaded with material or empty at the current point in step S3 are as follows. When the absolute value of any one of the first vibration change amplitude A _{(pp) 1} and the second vibration change amplitude A _{(pp) 2} is greater than the second threshold, it is determined that the conveyor belt 200 is starting to operate at the current time point and To carry materials. The second threshold is greater than the first threshold.

Specifically, the present invention uses the vibration signal at the previous time point and the vibration signal at the current time point to perform calculations and compares the calculation result with a second threshold value greater than the first threshold value to further determine whether the conveyor belt 200 is unloaded or loaded. status, the second threshold can be the operator's experience value or a reference value calculated based on historical data. In other words, the present invention detects the no-load/loaded state of the conveyor belt 200 through the three-axis vibration measurement function of the three-axis accelerometers 122 and 124 in steps S1 and S3.

Among them, the details of step S4, step S5 and step S6 are as follows. First, in step S4, the wireless temperature detector 146 provided above the conveyor belt 200 is used to obtain the ambient temperature at the current point in time (indicated by _Te in this article) and the raw material at the current point in time of the raw material 400 on the conveyor belt 200. Temperature (expressed in this article as _Tm ). Next, in step S5, the wireless temperature detector 142 provided on the first side of the conveyor belt 200 is used to obtain the first adhesive temperature (in This article is represented by T _bt1i ) and the wireless temperature detector 144 provided on the second side of the conveyor belt 200 is used to obtain the second back glue temperature at the current point in time (represented by i in this article) of the second side of the conveyor belt 200 (Denoted as T _bt2i in this article). Then, in step S6, based on the current ambient temperature _Te , raw material temperature T _m , first adhesive temperature T _bt1i , second adhesive temperature T _bt2i , and first vibration signal (A _x1i , A _y1i , _Az1i ) and the second vibration signal (A _x2i , A _y2i , _Az2i ) to determine whether the conveyor belt 200 is unilaterally deflected and has an abnormally high temperature on one side at the current point in time.

T_bt1i≧T_m,T_e或

T_bt2i≧T_m,T_e)的情況下，對於輸送帶200於當前時點i的第一振動訊號(A_x1i,A_y1i,A_z1i)與第二振動訊號(A_x2i,A_y2i,A_z2i)進行下式式(3)之運算：△A _diff =(A _x1i +A _y1i +A _z1i )-(A _x2i +A _y2i +A _z2i ) (3)以取得輸送帶200於當前時點的偏斜偵測量(在本文中以△A_diff表示)。最後，當偏斜偵測量△A_diff的絕對值|△A _diff |大於或等於第三閥值時，則進入步驟S7，判定輸送帶200於當前時點發生單側偏斜且發生單側異況高溫。 The details of determining whether the conveyor belt 200 has unilateral deflection and abnormal high temperature on one side at the current point in step S6 are as follows. First, determine whether either of the first adhesive temperature T _bt1i and the second adhesive temperature T _bt2i is greater than the raw material temperature T _m and greater than the ambient temperature _Te . Then, when either of the first adhesive temperature T _bt1i and the second adhesive temperature T _bt2i is greater than the raw material temperature T _m and greater than the ambient temperature Te ( _i.e.

T _bt1i ≧T _m ,T _e or

In the case of T _bt2i ≧T _m , _Te ), for the first vibration signal (A _x1i , A _y1i , A _z1i ) and the second vibration signal (A _x2i , A _y2i , A _z2i ) of the conveyor belt 200 at the current time point i ) perform the calculation of the following formula (3): △ A _diff =( A _{x 1 i} + A _{y 1 i} + A _{z 1 i} )-( A _{x 2 i} + A _{y 2 i} + A _{z 2 i} ) (3 ) to obtain the deflection detection amount of the conveyor belt 200 at the current point in time (expressed as ΔA _diff in this article). Finally, when the absolute value of the deflection detection quantity ΔA _diff | ΔA _diff | is greater than or equal to the third threshold, step S7 is entered to determine that the conveyor belt 200 has a unilateral deflection and a unilateral abnormality at the current point in time. Conditions of high temperature.

Specifically, the present invention uses the vibration signals of the opposite sides of the conveyor belt 200 at the current time point to perform calculations and compares the calculation results with a third threshold to determine the deviation phenomenon of the conveyor belt 200. The third threshold can be operate The experience value of personnel or the reference value calculated based on historical data. In other words, the present invention detects the deviation phenomenon of the conveyor belt 200 through the three-axis vibration measurement function of the three-axis accelerometers 122 and 124 in step S6.

The specific method of determining whether the conveyor belt 200 has unilateral deflection and abnormal high temperature on one side at the current point in step S6 is described below. When the deflection detection amount is greater than or equal to 0 (that is, △A _diff ≧0) and the deflection detection amount is greater than or equal to the third threshold (that is, △A _diff ≧the third threshold), it is determined that the conveyor belt 200 The first side has a unilateral deflection and a unilateral abnormal high temperature at the current time point (step S7). In addition, when the deflection detection amount is less than or equal to 0 (i.e., △A _diff ≦0) and the absolute value of the deflection detection amount is greater than or equal to the third threshold (i.e., |△ A _diff |≧the third threshold) , then it is determined that the second side of the conveyor belt 200 has unilateral deflection and unilateral abnormal high temperature at the current point in time (step S7).

In addition, if in step S6, the absolute value of the deflection detection amount is less than the third threshold (i.e. |△ A _diff | Unilateral deflection, and then perform temperature rise abnormality detection.

Among them, the specific method of detecting abnormal temperature rise in step S8 is described below. First, a weighted moving average (WMA) algorithm is used to estimate the conveying at the next time point immediately following the current time point based on the adhesive temperatures of the first side of the conveyor belt 200 at the last five time points. The fifth adhesive temperature on the first side of the conveyor belt 200 is estimated to be the sixth adhesive temperature on the second side of the conveyor belt 200 at the next time point based on the adhesive temperatures on the second side of the conveyor belt 200 at the last five time points. Glue temperature. Then, predict the conveyor belt 200 at the next time point based on the fifth adhesive temperature and the sixth adhesive temperature. Whether any abnormal temperature rise occurs.

The details of the temperature rise abnormality detection in step S8 are as follows. A weighted moving average algorithm is used to obtain the fifth adhesive temperature (T _{bt1(i+1) in this article) of the first side of the conveyor belt 200 at the next time point (in this article, (i+1)).} Expressed), the calculation formula of the fifth adhesive temperature is as follows: T _{bt 1( i +1)} = W ₁ T _{bt 1 i} + W ₂ T _{bt 1( i - i )} + W ₃ T _{bt 1 ( i -2)} + W ₄ T _{bt 1( i -3)} + W ₅ T _{bt 1( i -4)} (4) Where W ₁ , W ₂ , W ₃ , W ₄ , W ₅ are weight values and W ₁ >W ₂ >W ₃ >W ₄ >W _5. The weight values W ₁ , W ₂ , W ₃ , W ₄ , and W ₅ can be the operator's experience values or reference values calculated based on historical data. Where T _bt1i is the first adhesive temperature of the first side of the conveyor belt 200 at the current time point i, and T _{bt1 (i-1)} is the adhesive temperature of the first side of the conveyor belt 200 at the previous time point (i-1). , where T _{bt1 (i-2)} is the back glue temperature one time point before the previous time point on the first side of the conveyor belt 200 , where T _{bt1 (i-3)} is two time points before the previous time point on the first side of the conveyor belt 200 The adhesive temperature of T _{bt1 (i-4)} is the adhesive temperature of the first side of the conveyor belt 200 three time points before the previous time point. In addition, a weighted moving average algorithm is used to obtain the sixth adhesive temperature of the second side of the conveyor belt 200 at the next time point (represented by T _{bt2 (i+1)} in this article), and the calculation formula of the sixth adhesive temperature is As shown in the following equation (5): T _{bt 2( i +1)} = W ₁ T _{bt 2 i} + W ₂ T _{bt 2( i - i )} + W ₃ T _{bt 2( i -2)} + W ₄ T _{bt 2( i -3)} + W ₅ T _{bt 2( i -4)} (5) where T _bt2i is the second adhesive temperature at the current time point i on the second side of the conveyor belt 200 , where T _bt2(i-1) is the adhesive temperature at the previous time point (i-1) on the second side of the conveyor belt 200, where T _bt2(i-2) is the adhesive temperature at a time point before the previous time point on the second side of the conveyor belt 200, where T _bt2(i-3) is the adhesive temperature at two time points before the previous time point on the second side of the conveyor belt 200, where T _bt2(i-4) is the adhesive temperature at three time points before the previous time point on the second side of the conveyor belt 200 temperature.

Specifically, the present invention uses a weighted moving average algorithm to predict the adhesive temperatures on opposite sides of the conveyor belt 200 at the next point in time and determine abnormal temperature rises accordingly. Among them, the reason why the present invention uses a weighted moving average algorithm to predict the adhesive temperature at the next point in time is that if the adhesive temperature measured by a wireless thermodetector is used, the adhesive temperature may obtain outliers due to some uncertain factors. ), thus causing subsequent misjudgments. Regarding the method of judging abnormal temperature rise, for example, we can set the temperature warning threshold of the first side of the conveyor belt 200. In this way, the fifth adhesive temperature of the first side of the conveyor belt 200 at the next time point When the temperature warning threshold of the first side of the conveyor belt 200 is exceeded, a corresponding alarm may be issued. For example, we can set the temperature warning threshold on the second side of the conveyor belt 200 , so that when the sixth adhesive temperature on the second side of the conveyor belt 200 at the next time point exceeds the temperature on the second side of the conveyor belt 200 When the temperature warning threshold is reached, the corresponding alarm can be issued. For example, we can set a temperature difference warning threshold between the first side and the second side of the conveyor belt 200 . In this way, when the temperature difference between the fifth adhesive temperature on the first side of the conveyor belt 200 and the sixth adhesive temperature on the second side at the next time point exceeds the temperature difference warning threshold between the first side and the second side of the conveyor belt 200 When, the corresponding alarm can be issued. Therefore, corresponding precautions can be taken according to the alarms issued, such as using a fire extinguishing system and implementing automatic water spraying to cool down, so as to predict the occurrence of conveyor belt fires in advance and prevent fire accidents before they occur.

In addition, if in step S2, when neither the absolute value of the first vibration change amplitude nor the absolute value of the second vibration change amplitude is greater than the first threshold, then Entering step S9, it is determined that the conveyor belt 200 is in a stopped state at the current time point, and then static temperature rise detection is performed.

In addition, if in step S3, when the absolute value of either the first vibration change amplitude or the second vibration change amplitude is greater than the first threshold but not greater than the second threshold, then step S10 is entered to determine whether the conveyor belt 200 starts operation at the current time point and is no-load and no-load, and then performs no-load temperature rise detection.

The above-mentioned static temperature rise detection in step S9 and no-load temperature rise detection in step S10 are basically similar to the temperature rise abnormality detection in step S8, that is, a weighted moving average algorithm will be used to predict the next time. Point the glue temperature on the opposite sides of the conveyor belt 200 and judge the temperature rise abnormality accordingly. Since the method is similar, it will not be described again here. However, it should be noted that the weight values W ₁ , W ₂ , W ₃ , and W ₄ and W ₅ may adopt different values. This is because the abnormal temperature rise in step S8 is detected as material carrying, the static temperature rise in step S9 is detected as a stopped state, and the no-load temperature in step S10 is detected. The temperature rise detection is in the case of no material and no load. The temperature rise abnormality performance in these cases will be different. For example, the temperature rise abnormality performance of the static temperature rise in the stopped state may be a relatively rapid temperature rise (such as exponential type). temperature rise), and the abnormal temperature rise performance of the no-load temperature rise without material and no load may be a slower temperature rise (such as a linear temperature rise). Therefore, the different temperature rise performances of these situations should be based on the to select appropriate weight values.

Based on the above, the present invention proposes a method for monitoring conveyor belts. In addition to effectively identifying potential abnormal high temperatures on conveyor belts, the present invention can also perform conveyor belt monitoring. Operation status monitoring. Specifically, while there are many causes of conveyor belt fires, the conveyor belt remains the last and most critical concern. Therefore, the present invention proposes a method for monitoring conveyor belts. In a non-contact (wireless temperature detection) manner, wireless temperature detectors (two groups) are installed on the left and right sides of the same position on the conveyor belt to detect the adhesive surface of the conveyor belt. Temperature, while also detecting the raw material temperature and ambient temperature of the raw materials carried by the conveyor belt as a reference basis, a weighted moving average algorithm is used to effectively identify abnormal temperature rises on the conveyor belt, and is equipped with a fire extinguishing system to implement automatic water spraying to cool down. It can predict the occurrence of conveyor belt fires in advance and prevent fire accidents before they happen. In addition, the present invention also has a three-axis vibration measurement function. Through the vibration signals provided by the three-axis accelerometers installed on both sides of the conveyor belt, the start-stop and empty/heavy-load status of the conveyor belt can be effectively known. At the same time, the conveyor belt is in The deflection phenomenon that occurs during operation can also be effectively detected; before the roller is damaged due to high temperature due to severe friction, the present invention can also detect it through vibration signals. By comparing the temperature of the adhesive on the opposite sides of the conveyor belt, on the one hand, the possible fire accident caused by the temperature rise on one side due to belt deviation can be avoided; on the other hand, the conveyor belt can be installed in advance before it is seriously damaged. Before an emergency shutdown occurs due to deviation, the user is reminded in advance so that appropriate adjustments can be made. This invention refers to the types and types of conveyor belt fire accidents in the past, and uses wireless temperature detectors and three-axis accelerometers to monitor the conveyor belt status. In addition to quickly and accurately detecting abnormal temperature rise of the conveyor belt, it also has the ability to detect the conveyor belt operating status and Deflection detection and other functions. In addition to information provision and deflection detection that can monitor the operating status of the conveyor belt, fire accidents can be avoided immediately and quickly by combining a water spray cooling system.

The invention proposes a monitoring method for conveyor belts to avoid the expansion of disasters. This invention is an integrated technology based on wireless temperature detectors and three-axis accelerometers to identify abnormal high temperatures and detect operating conditions of conveyor belts. Therefore, the present invention will be able to identify the detected abnormalities based on the status of the conveyor belt, so as to facilitate the classification and display of alarms, so as to quickly grasp the situation, take corresponding measures, and immediately provide early warning for early abnormalities, effectively controlling the occurrence of accidents. Scope.

The invention can effectively achieve the result of early identification of abnormal conditions of the conveyor belt. For example: temperature rise caused by friction between the conveyor belt and the bearing contact surface, temperature rise caused by poor bearing lubrication, conveyor belt skew operation, conveyor belt temperature rise detection, etc. Therefore, through the conveyor belt monitoring method of the present invention, in addition to all-round abnormality confirmation of the conveyor belt, the operating status of the conveyor belt can also be monitored, so as to provide users with reliable and real-time alarm messages.

The features of several embodiments are summarized above, so that those skilled in the art can better understand the aspects of the present invention. Those skilled in the art should understand that they can easily use the present invention as a basis to design or modify other processes and structures to achieve the same goals and/or achieve the same advantages as the embodiments introduced here. . Those skilled in the art should also understand that these equivalent structures do not deviate from the spirit and scope of the present invention, and they can make various changes, substitutions and changes without departing from the spirit and scope of the present invention.

S1-S10: Steps

Claims (10)

A method for monitoring a conveyor belt, including: at a previous time point, obtaining a third vibration signal of a first side of a conveyor belt and a fourth vibration signal of a second side of the conveyor belt; and immediately following At a current time point after the previous time point, a first vibration signal of the first side of the conveyor belt and a second vibration signal of the second side of the conveyor belt are obtained, wherein the first side and the second side Opposite each other in a first direction, wherein the conveyor belt is transported toward a second direction perpendicular to the first direction; according to the first vibration signal, the second vibration signal, the third vibration signal and the fourth vibration signal to determine whether the conveyor belt is running or stopped at the current point in time; when it is determined that the conveyor belt is running, based on the first vibration signal, the second vibration signal, the third vibration signal and the fourth vibration signal To determine whether the conveyor belt is loaded with material or without material at the current point in time; and when it is determined that the conveyor belt is running and loaded with material at the current point in time, obtain a first adhesive on the first side of the conveyor belt temperature and a second adhesive temperature on the second side of the conveyor belt. Based on the first vibration signal, the second vibration signal, the first adhesive temperature and the second adhesive temperature, it is determined whether the conveyor belt Unilateral deflection occurs and unilateral abnormal high temperature occurs. The monitoring method of the conveyor belt as described in claim 1 further includes: using two sets of three monitors respectively provided on the first side and the second side of the conveyor belt. use a shaft accelerometer to obtain the first vibration signal on the first side of the conveyor belt and the second vibration signal on the second side; and use the accelerometers respectively provided on the first side and the second side of the conveyor belt. Two sets of wireless temperature detectors are used to obtain the first adhesive temperature on the first side of the conveyor belt and the second adhesive temperature on the second side. The method for monitoring a conveyor belt according to claim 1, wherein each of the first vibration signal, the second vibration signal, the third vibration signal and the fourth vibration signal is a three-axis vibration value; wherein The first vibration signal of the current time point i on the first side of the conveyor belt is represented by (A _x1i , A _y1i , A _z1i ); wherein the second vibration signal of the current time point i on the second side of the conveyor belt The vibration signal is represented by (A _x2i ,A _y2i ,A _z2i ); wherein the third vibration signal of the previous time point (i-1) on the first side of the conveyor belt is represented by (A _x1(i-1) ,A _y1(i-1) ,A _z1(i-1) ) represents; wherein the fourth vibration signal of the previous time point (i-1) on the second side of the conveyor belt is represented by (A _x2(i-1) ,A _y2(i-1) ,A _z2(i-1 ) represent; the monitoring method of the conveyor belt further includes: subtracting the third vibration signal from the first vibration signal and performing the following calculation, (A _x1i -A _x1(i-1) )+(A _y1i -A _y1(i-1) )+(A _z1i -A _z1(i-1) ) to obtain the first side of the conveyor belt A first vibration change amplitude between the previous time point and the current time point; subtract the fourth vibration signal from the second vibration signal and perform the following formula calculation, (A _x2i -A _x2(i-1) )+ (A _y2i -A _y2(i-1) )+(A _z2i -A _z2(i-1) ), to obtain a second value of the second side of the conveyor belt between the previous time point and the current time point. The vibration change amplitude; and when the absolute value of any one of the first vibration change amplitude and the second vibration change amplitude is greater than a first threshold, it is determined that the conveyor belt is starting to run at the current time point. The monitoring method of the conveyor belt as described in claim 3 further includes: when neither the absolute value of the first vibration change amplitude nor the absolute value of the second vibration change amplitude is greater than the first threshold, then It is determined that the conveyor belt is in a stopped state at the current time point; when the absolute value of any one of the first vibration change amplitude and the second vibration change amplitude is greater than a second threshold, it is determined that the conveyor belt is in the stopped state. The current time point is when the operation is started and there is material transportation, wherein the second threshold is greater than the first threshold; and when the absolute value of any one of the first vibration change amplitude and the second vibration change amplitude is greater than the third When a threshold value is not greater than the second threshold value, it is determined that the conveyor belt is running at the current time point and has no material or load. The monitoring method of the conveyor belt as described in claim 4 further includes: when it is determined that the conveyor belt is running and carrying materials at the current time point, using an upper wireless temperature detector located above the conveyor belt to detect Obtain an ambient temperature at the current time point and a raw material temperature of the raw material on the conveyor belt; when either the first adhesive temperature and the second adhesive temperature are greater than the raw material temperature and greater than the ambient temperature Next, perform the following formula calculation on the first vibration signal and the second vibration signal of the conveyor belt at the current time point i, (A _x1i +A _y1i +A _z1i )-(A _x2i +A _y2i +A _z2i ), To obtain a deflection detection amount of the conveyor belt at the current point in time; and when the absolute value of the deflection detection amount is greater than or equal to a third threshold, it is determined that the conveyor belt is unilateral at the current point in time. Deflection and abnormal high temperature occur on one side. The monitoring method of the conveyor belt as described in claim 5 further includes: when the deflection detection amount is greater than or equal to 0 and greater than or equal to the third threshold, then determining that the first side of the conveyor belt is A unilateral deflection occurs at the current time point and a unilateral abnormally high temperature occurs; and when the deflection detection amount is less than or equal to 0 and the absolute value of the deflection detection amount is greater than or equal to the third threshold, it is determined The second side of the conveyor belt has a unilateral deflection and a unilateral abnormally high temperature at the current point in time. The method for monitoring a conveyor belt as described in claim 5 further includes: when the absolute value of the deflection detection amount is less than the third threshold, it is determined that the conveyor belt has not unilaterally deflected at the current time point. Skew; when it is determined that the conveyor belt does not deflect on one side at the current point in time, borrow A weighted moving average algorithm is used to estimate a fifth adhesive temperature of the first side of the conveyor belt at the next time point immediately after the current time point and to estimate the temperature of the conveyor belt at the next time point. A sixth adhesive temperature on the second side; and predicting whether a temperature rise abnormality will occur in the conveyor belt at the next time point based on the fifth adhesive temperature and the sixth adhesive temperature. The monitoring method of the conveyor belt as described in claim 7, wherein the fifth adhesive temperature is expressed by the following formula, W ₁ T _bt1i +W ₂ T _bt1(i-1) +W ₃ T _bt1(i-2) + W ₄ T _bt1(i-3) +W ₅ T _bt1(i-4) , where W ₁ , W ₂ , W ₃ , W ₄ , and W ₅ are weight values and W ₁ >W ₂ >W ₃ >W ₄ >W ₅ , where T _bt1i is the first adhesive temperature at the current time point i on the first side of the conveyor belt, and T _bt1(i-1) is the previous time point on the first side of the conveyor belt. The adhesive temperature of (i-1), where T _{bt1 (i-2)} is the adhesive temperature of the first side of the conveyor belt at a time point before the previous time point, where T _{bt1 (i-3)} is the conveyor belt temperature. The adhesive temperature of the first side of the belt two time points before the previous time point, where T _{bt1 (i-4)} is the adhesive temperature of the first side of the conveyor belt three time points before the previous time point, where the th The six-back glue temperature is expressed by the following formula, W ₁ T _bt2i +W ₂ T _bt2(i-1) +W ₃ T _bt2(i-2) +W ₄ T _bt2(i-3) +W ₅ T _{bt2(i- 4)} , where T _bt2i is the second adhesive temperature at the current time point i on the second side of the conveyor belt, and T _bt2(i-1) is the previous time point on the second side of the conveyor belt ( The adhesive temperature of i-1), where T _{bt2 (i-2)} is the adhesive temperature of the second side of the conveyor belt at a time point before the previous time point, where T _{bt2 (i-3)} is the conveyor belt The glue temperature of the second side two time points before the previous time point, where T _{bt2 (i-4)} is the glue temperature of the second side of the conveyor belt three time points before the previous time point. The monitoring method of the conveyor belt as described in claim 1 further includes: when it is determined that the conveyor belt is in a stopped state at the current time point, using a weighted moving average algorithm to estimate the next time immediately after the current time point. The adhesive temperature of the first side of the conveyor belt at one time point is estimated to be the adhesive temperature of the second side of the conveyor belt at the next time point, so as to predict the stop state of the conveyor belt at the next time. Whether any abnormal temperature rise occurs at any time. The monitoring method of the conveyor belt as described in claim 4 further includes: when it is determined that the conveyor belt is running and has no material and no load at the current time point, using a weighted moving average algorithm to estimate the time immediately following the conveyor belt. The glue temperature of the first side of the conveyor belt at the next time point after the current time point is estimated to be the glue temperature of the second side of the conveyor belt at the next time point, so as to predict the start of operation and no material. Whether the temperature rise of the unloaded conveyor belt will occur at the next point in time.

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