Real-time control system based on roller way conveying line and dynamic speed regulation method of real-time control system

Abstract

The invention discloses a real-time control system based on a roller way conveying line and a dynamic speed regulation method of the real-time control system, and particularly relates to the technical field of conveying line control. The current position information of the goods and the current speed information of the roller way conveying line are obtained through data collected by a sensor; the required speed of the next frame of the roller way conveying line is calculated; preset frequency converter parameters, motor parameters and roller way conveying line parameters are combined with the required speed, and analog quantity current needing to be output is calculated; the obtained analog quantity current is transmitted to a corresponding frequency converter and a motor through a communication module, so that the roller way conveying line is driven to work; dynamic speed regulation of the roller way conveying line is achieved. Parameters of the frequency converter are adjusted according to information of the sensor, motion control over the roller way conveying line is achieved, and the work efficiency is improved; if a plurality of sections of roller way conveying lines exist, the transportation of the goods at the junction is more stable by coordinating the speeds of the two sections of roller way conveying lines.

Description

Technical Field

[0001] The present invention relates to the technical field of conveyor line control, and more specifically, to a real-time control system based on a roller conveyor line and a dynamic speed regulation method thereof. Background Art

[0002] It is known that the roller conveyor line is a mechanized conveying equipment composed of multiple parallel arranged rollers. The rollers are driven to rotate by an electric motor to achieve continuous transmission of materials in the horizontal or inclined direction. Due to its modular design and high adaptability, it has become one of the core components of the modern industrial automation logistics system, and plays an important role in industrial manufacturing, logistics warehousing and other fields.

[0003] However, in the existing roller conveyor line control scheme, PLC equipment is often used to adjust the parameters of the frequency converter; this method has certain functional limitations. For example, when the usage scenario is very complex and there are many external sensors, it is often not possible to complete it efficiently if only PLC is used; therefore, a real-time control system based on a roller conveyor line and its dynamic speed regulation method are proposed as a further improvement. Summary of the invention

[0004] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides a real-time control system based on a roller conveyor line and a dynamic speed regulation method thereof to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a dynamic speed regulation method based on a roller conveyor line, comprising the following steps:

[0006] S1: Preset inverter parameters, motor parameters and roller conveyor line parameters; obtain the position of the goods on the roller conveyor line and the current speed of the roller conveyor line;

[0007] S2: Calculate the required speed v of the roller conveyor line for the next frame based on the position and speed obtained in S1;

[0008] S3: According to the inverter parameters, motor parameters, roller conveyor line parameters preset in S1 and the required speed v obtained in S2, the analog current A to be output is calculated by the formula;

[0009] S31: Based on the roller diameter D of the roller conveyor line and the reduction ratio k of the motor and the reducer, the target speed p of the motor is calculated by the following formula:

[0010]

[0011] S32: Based on the inverter parameters, the target speed p of the motor is converted into the output frequency setting value r of the inverter by the following formula:

[0012] r = p*j+i;

[0013] S33: The output frequency setting value r is converted into the analog current A of the RS485 communication module by the following formula:

[0014] A = m*r;

[0015] S4: The analog current obtained in S33 is transmitted to the corresponding frequency converter and motor through the communication module, so that it drives the roller conveyor line to work; the dynamic speed regulation of the roller conveyor line is realized; and then return to S1.

[0016] Furthermore, the steps S1-S4 are continuously executed in each operation cycle of the roller conveyor line, and the time interval between adjacent operation cycles is no more than 10 ms.

[0017] Furthermore, in S2, the method for calculating the speed required for the next frame of the roller conveyor line comprises the following steps:

[0018] S21: Detect the position of the goods in real time by using a plurality of photoelectric sensors distributedly deployed on the roller conveyor line; the plurality of photoelectric sensors include: a starting point trigger unit, a deceleration zone trigger unit and an end point trigger unit;

[0019] S22: When the starting point trigger unit is triggered, it is determined that the goods are located at the starting point of the current conveying section, and the linear acceleration algorithm is started to increase the roller conveyor line speed from the zero initial value to the rated maximum speed V according to the preset slope. max , and after reaching the maximum value, it switches to a constant speed V max High speed constant speed mode;

[0020] S23: When the through-beam photoelectric sensor is not activated by any trigger unit, it is determined that the goods are in the middle area of ​​the conveyor line, and the roller conveyor line maintains the current speed unchanged;

[0021] S24: When the deceleration zone trigger unit is triggered, it is determined that the goods enter the deceleration zone before the end point, and the linear deceleration algorithm is started to reduce the roller conveyor line speed from the current value to the rated minimum speed V according to the preset slope. min , and after reaching the minimum value, it switches to a constant speed V min Low speed and uniform speed mode;

[0022] S25: When the end point trigger unit is triggered, it is determined that the goods have reached the end of the roller conveyor section, and the roller conveyor line performs a braking operation until it stops completely.

[0023] Furthermore, in S22 and S24, the speed change slope in the linear acceleration algorithm and the linear deceleration algorithm is determined according to the length of the roller conveyor line, the mass of the goods and the rated maximum speed V max and rated minimum speed Vmin Dynamic calculation is performed, and the distance between adjacent photoelectric sensors and the length of the deceleration zone satisfy the following relationship:

[0024] L≥(V max -V min ) / (2a),

[0025] Where L is the length of the deceleration zone and a is the preset maximum acceleration value.

[0026] Further, in said S31, the preset roller conveyor line speed v is in m / s; the motor speed is in r / min;

[0027] In S32, j and i are correction coefficients;

[0028] In S33, m is the correction coefficient: and satisfies A≤20mA.

[0029] Furthermore, in S4, during the operation of the roller conveyor line, there are three safety measures: safety grating emergency stop, button emergency stop, and fault emergency stop.

[0030] A real-time control system based on a roller conveyor line comprises the dynamic speed regulation method based on a roller conveyor line.

[0031] Technical effects and advantages of the present invention:

[0032] Compared with the prior art, the present invention can adjust the inverter parameters according to the information of the sensor, and finally achieve the motion control of the roller conveyor line, thereby improving the work efficiency; if there are multiple sections of roller conveyor lines, the speed of two sections of roller conveyor lines can be coordinated to make the transportation of goods at the junction smoother; three safety measures are used to improve safety; thus solving the problem of low work efficiency of the existing roller conveyor line caused by only using PLC when the usage scenario is very complex and there are many external sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The figure is a flow chart of the method of the present invention.

[0034] Figure 2 It is a schematic diagram of S3 of the present invention.

[0035] Figure 3 Schematic diagram of three safety measures of the present invention.

[0036] Figure 4 It is a system block diagram of the present invention.

[0037] The accompanying drawings are marked as follows:

[0038] 1. Roller conveyor line; 2. Photoelectric sensor; 3. Industrial computer; 4. RS485 to TCP module; 5. Frequency converter; 6. Motor. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0040] As attached Figure 1 and attached Figure 2 A dynamic speed regulation method based on a roller conveyor line is shown, comprising the following steps:

[0041] S1: Preset the inverter parameters, motor parameters and roller conveyor line parameters; use the data collected by the sensor to obtain the current location information of the goods and the current speed information of the roller conveyor line;

[0042] Among them, a socket-based communication will be established. On the one hand, the triggering status of the photoelectric sensor is obtained through digital quantity, and then the current position information of the goods on the roller conveyor line is obtained; on the other hand, the current frequency of the inverter is obtained through analog quantity, and then the current speed information of the roller conveyor line is obtained;

[0043] S2: Calculate the required speed of the next frame of the roller conveyor line based on the data obtained in S1;

[0044] S21: Detect the position of the goods in real time by using a plurality of photoelectric sensors distributedly deployed on the roller conveyor line; the plurality of photoelectric sensors include: a starting point trigger unit, a deceleration zone trigger unit and an end point trigger unit;

[0045] S22: When the starting point trigger unit is triggered, it is determined that the goods are located at the starting point of the current conveying section, and the linear acceleration algorithm is started to increase the roller conveyor line speed from the zero initial value to the rated maximum speed V according to the preset slope. max , and after reaching the maximum value, it switches to a constant speed V max High speed constant speed mode;

[0046] S23: When the through-beam photoelectric sensor is not activated by any trigger unit, it is determined that the goods are in the middle area of ​​the conveyor line, and the roller conveyor line maintains the current speed unchanged;

[0047] S24: When the deceleration zone trigger unit is triggered, it is determined that the goods enter the deceleration zone before the end point, and the linear deceleration algorithm is started to reduce the roller conveyor line speed from the current value to the rated minimum speed V according to the preset slope. min , and after reaching the minimum value, it switches to a constant speed V min Low speed and uniform speed mode;

[0048] S25: When the end point trigger unit is triggered, it is determined that the goods have reached the end of the roller conveyor section, and the roller conveyor line performs a braking operation until it stops completely.

[0049] S3: Combine the inverter parameters, motor parameters and roller conveyor line parameters preset in S1 with the required speed obtained in S2 to calculate the analog current to be output;

[0050] S31: Based on the motor and reducer parameters of the roller conveyor line, the roller diameter D of the roller conveyor line and the reduction ratio k of the motor and reducer are pre-set, and the preset roller conveyor line speed v unit is converted from "m / s" to the motor speed unit "r / min", and the target speed p of the motor is calculated by the following formula:

[0051]

[0052] S32: Based on the inverter parameters, the following formula is obtained through experiments and corrections:

[0053] r = p*j+i; (where j and i are correction coefficients);

[0054] Convert the motor's target speed p into the inverter's output frequency setting value r:

[0055] S33: The output frequency setting value r of the frequency converter is converted into the analog current A of the RS485 communication module by the following formula:

[0056] A=m*r;(wherein m is the correction coefficient): and satisfies A≤20mA.

[0057] S4: The analog current A obtained in S33 is transmitted to the corresponding frequency converter and motor through the communication module, so that it drives the roller conveyor line to work; the dynamic speed regulation of the roller conveyor line is realized; and then return to S1.

[0058] The above formula and the parameters involved therein are described in detail with specific examples:

[0059] If the preset roller conveyor line speed v reaches 0.02m / s,

[0060] The reduction ratio k of the motor and reducer is set to 50.

[0061] The roller diameter D of the roller conveyor line is set to 0.042m.

[0062] According to the formula, the target speed p of the motor is: 454.95r / min;

[0063] In the experimental environment, j is 89.1 and i is -0.61, so the output frequency setting value r of the inverter is calculated according to the formula: 4.49;

[0064] In the experimental environment, m is 2.29, and the analog current A calculated according to the formula is: 1.96mA.

[0065] Among them, the communication module of the RS485 to TCP module will be used to send analog signals using the modbus protocol. The A value calculated in S33 will be used to generate a corresponding message according to the modbus protocol requirements, and the message will be sent to ensure that a normal analog signal is generated.

[0066] Among them, when the goods are at the junction of two sections of roller conveyor lines, a photoelectric sensor is set at the junction of the two sections of roller conveyor lines, and the speed of the two sections of roller conveyor lines is coordinated to make the transportation of goods at the junction more stable;

[0067] The specific method of coordinating the speed of two roller conveyor lines is as follows:

[0068] When the goods on the previous roller conveyor line have been transported to near the end, the next roller conveyor line will be controlled to accelerate in advance. It is necessary to ensure that the speed has been adjusted before the goods touch the next roller conveyor line; that is, when the goods begin to touch the next roller conveyor line, the transportation speeds of the two roller conveyor lines are the same to ensure smooth transportation of the goods; when the goods completely leave the previous roller conveyor line, the previous roller conveyor line begins to decelerate until it stops.

[0069] In a preferred embodiment, as shown in the attached Figure 1 As shown, the steps S1-S4 are continuously executed in each operation cycle of the roller conveyor line, and the time interval between adjacent operation cycles is no more than 10 ms.

[0070] In a preferred embodiment, as shown in the attached Figure 1 As shown, in S22 and S24, the speed change slope in the linear acceleration algorithm and the linear deceleration algorithm is based on the length of the roller conveyor line, the mass of the goods and the rated maximum speed V max and rated minimum speed V min Dynamic calculation is performed, and the distance between adjacent photoelectric sensors and the length of the deceleration zone satisfy the following relationship:

[0071] L≥(V max -V min ) / (2a),

[0072] Where L is the length of the deceleration zone and a is the preset maximum acceleration value.

[0073] In a preferred embodiment, as shown in the attached Figure 3 As shown, in S4, during the operation of the roller conveyor line, there are three safety measures: safety grating emergency stop, button emergency stop, and fault emergency stop.

[0074] When there is a person within the range of the safety grating, the RS485 digital signal will be triggered. After the industrial computer learns this through the TCP to RS485 module, it will control the speed of the roller conveyor line to 0 and stop working until there is no more person in the safety grating. Then the speed will be automatically restored and the roller conveyor line will resume operation.

[0075] When the emergency stop button is pressed, the RS485 digital signal will be triggered, and the roller conveyor line will be controlled to stop working. However, when the signal disappears, it will not automatically resume, but you need to manually press the reset button to resume operation to ensure safety.

[0076] Fault emergency stop means that when the industrial computer program reports an error, the roller conveyor line speed is abnormal, or a communication failure occurs, the roller conveyor line will be controlled to stop working, and the system must be manually restarted to resume operation.

[0077] As attached Figure 4 As shown, a real-time control system based on a roller conveyor line includes the dynamic speed regulation method based on a roller conveyor line.

[0078] Among them, an embodiment of a real-time control system based on a roller conveyor line:

[0079] It includes: roller conveyor line 1, photoelectric sensor 2, industrial computer 3, RS485 to TCP module 4, frequency converter 5 and motor 6;

[0080] If a 2-section roller conveyor line is used, 1, 6 pairs of photoelectric sensors 2, 1 industrial computer 3, 1 RS485 to TCP module 4, 2 inverters 5, 2 motors 6;

[0081] Six pairs of through-beam photoelectric sensors 2 for detecting goods are distributed on both sides of the two sections of roller conveyor lines 1, the signal output end of the through-beam photoelectric sensor 2 is connected to the signal input end of the RS485 to TCP module 4, the signal output end 4 of the RS485 to TCP module is connected to the signal input end of the frequency converter 5, and the signal output end of the frequency converter 5 is connected to the signal input end of the motor 6; the signal input end and the signal output end of the RS485 to TCP module 4 are respectively connected to the signal output end and the signal input end of the industrial computer 3, and then through this control system, the roller conveyor line can realize accurate transportation of goods. In this process, there are three safety mechanisms: safety grating, button emergency stop, and fault emergency stop. When communicating with the frequency converter 5, a conventional speed prediction compensation algorithm is adopted to eliminate the response delay of the frequency converter, so that the control result is more accurate.

[0082] It should be noted that the various embodiments of the systems and methods described above in this article can be implemented in general-purpose computers, special-purpose computers or other programmable data processing devices. It should be understood by those skilled in the art that various functional modules can be added, deleted, modified and combined according to design requirements and other factors, and the communication method with the motor can also be modified and configured according to the needs of the entire intelligent system. The above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention. In this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the term "includes", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such a process, method, article or device.

[0083] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A dynamic speed regulation method based on a roller conveyor line, characterized in that: The steps include: S1: Preset inverter parameters, motor parameters and roller conveyor line parameters; obtain the position of the goods on the roller conveyor line and the current speed of the roller conveyor line; S2: Calculate the required speed v of the roller conveyor line for the next frame based on the position and speed obtained in S1; S3: According to the inverter parameters, motor parameters, roller conveyor line parameters preset in S1 and the required speed v obtained in S2, the analog current A to be output is calculated by the formula; S31: Based on the roller diameter D of the roller conveyor line and the reduction ratio k of the motor and the reducer, the target speed p of the motor is calculated by the following formula: S32: Based on the inverter parameters, the target speed p of the motor is converted into the output frequency setting value r of the inverter by the following formula: r = p*j+i; S33: The output frequency setting value r is converted into the analog current A of the RS485 communication module by the following formula: A = m*r; S4: The analog current obtained in S33 is transmitted to the corresponding frequency converter and motor through the communication module, so that it drives the roller conveyor line to work; the dynamic speed regulation of the roller conveyor line is realized; and then return to S1.

2. The dynamic speed regulation method based on a roller conveyor line according to claim 1 is characterized in that: The steps S1-S4 are continuously executed in each operation cycle of the roller conveyor line, and the time interval between adjacent operation cycles is no more than 10ms.

3. The dynamic speed regulation method based on a roller conveyor line according to claim 1 is characterized in that: In S2, the method for calculating the speed required for the next frame of the roller conveyor line includes the following steps: S21: Detect the position of the goods in real time by using a plurality of photoelectric sensors distributedly deployed on the roller conveyor line; the plurality of photoelectric sensors include: a starting point trigger unit, a deceleration zone trigger unit and an end point trigger unit; S22: When the starting point trigger unit is triggered, it is determined that the goods are located at the starting point of the current conveying section, and the linear acceleration algorithm is started to increase the roller conveyor line speed from the zero initial value to the rated maximum speed V according to the preset slope. max , and after reaching the maximum value, it switches to a constant speed V max High speed constant speed mode; S23: When the through-beam photoelectric sensor is not activated by any trigger unit, it is determined that the goods are in the middle area of ​​the conveyor line, and the roller conveyor line maintains the current speed unchanged; S24: When the deceleration zone trigger unit is triggered, it is determined that the goods enter the deceleration zone before the end point, and the linear deceleration algorithm is started to reduce the roller conveyor line speed from the current value to the rated minimum speed V according to the preset slope. min , and after reaching the minimum value, it switches to a constant speed V min Low speed and uniform speed mode; S25: When the end point trigger unit is triggered, it is determined that the goods have reached the end of the roller conveyor section, and the roller conveyor line performs a braking operation until it stops completely.

4. The dynamic speed regulation method based on a roller conveyor line according to claim 3 is characterized in that: In S22 and S24, the speed change slope in the linear acceleration algorithm and the linear deceleration algorithm is based on the length of the roller conveyor line, the mass of the goods and the rated maximum speed V max and rated minimum speed V min Dynamic calculation is performed, and the distance between adjacent photoelectric sensors and the length of the deceleration zone satisfy the following relationship: L≥(V max -V min ) / (2a), Where L is the length of the deceleration zone and a is the preset maximum acceleration value.

5. The dynamic speed regulation method based on a roller conveyor line according to claim 1 is characterized in that: In the above S31, the preset roller conveyor line speed v is in m / s; the motor speed is in r / min; In said S32, j and i are correction coefficients; In S33, m is the correction coefficient: and satisfies A≤20mA.

6. The dynamic speed regulation method based on a roller conveyor line according to claim 1 is characterized in that: In S4, during the operation of the roller conveyor line, there are three safety measures: safety grating emergency stop, button emergency stop, and fault emergency stop.

7. A real-time control system based on a roller conveyor line, characterized in that: A dynamic speed regulation method based on a roller conveyor line comprising any one of claims 1-6.

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