PLC control system of sorting machine

Abstract

The utility model provides a PLC (Programmable Logic Controller) control system of a sorting machine, an annular trolley conveying line of the sorting machine is divided into a plurality of trolley subareas which are sequentially connected end to end, and each trolley subarea is provided with a positive integer of trolleys; the sorting machine PLC control system comprises an upper computer and trolley PLCs, the trolley PLCs and the trolley partitions are arranged in a one-to-one correspondence mode, the trolley PLCs are installed on any trolley in the corresponding trolley partitions, the trolley PLCs are in communication connection with driving elements of all the trolleys in the corresponding trolley partitions, and the trolley PLCs are in wireless communication connection with the upper computer. The sorting machine is suitable for sorting by driving a trolley through an electric roller and sorting by driving the trolley through an electromagnetic clutch.

Description

Technical Field

[0001] The utility model relates to the technical field of express sorting, in particular to a PLC control system for a sorting machine. Background Art

[0002] In the field of express sorting, automation and intelligent control technologies have developed rapidly. With the continuous increase in industrial and commercial land and labor costs, intensive sorting systems have higher operating efficiency because they can fully utilize space efficiency and correspondingly reduce labor requirements.

[0003] Currently, sorting machine control systems mostly use a single medium-to-large PLC to communicate with the WCS data server and control each execution unit. Control units such as the grid lock button and full grid photoelectric sensors are controlled using distributed remote IO. The trolley control unit is controlled based on leaky cable communication. External devices such as scanning cameras (used to identify package numbers) and grayscale meters (used to detect empty trays on trolleys) exchange information via serial port communication. As sorting systems become larger and larger, the number of controlled execution units increases, making PLC programs increasingly complex. The heavy processing tasks of a single PLC and the congestion of leaky cable cables greatly increase the program scanning cycle. The PLC scanning cycle determines the control accuracy of the system. For a scanning cycle of 20ms, at a high speed of 3 meters per second, a system deviation of 6cm in the package sorting action will occur, making it impossible to guarantee sorting accuracy.

[0004] To this end, a distributed PLC control system for sorting machines has emerged on the market. See Chinese invention patent application number CN116520760A, filed May 9, 2023, published August 1, 2023. This distributed PLC control system includes an infeed PLC, a loop management PLC, a slot PLC, and a host computer. The infeed PLC, loop management PLC, and slot PLC are all connected to the host computer. By modularizing and layering the content processed by a single PLC, using multiple PLCs to implement the functions of each module, and distributing processing requirements, the entire control system achieves higher execution accuracy and provides system redundancy. The failure of a single PLC will not affect the normal operation of the entire system.

[0005] At present, the distributed PLC control system is mainly used in the sorting machine with cylinder-driven trolley sorting. The sorting machine with cylinder-driven trolley sorting (see the Chinese utility model patent with application date of August 20, 2021, announcement date of February 25, 2022, and announcement number CN215902225U) generally includes a track, a cylinder arranged on the track and corresponding to the grid position, and a trolley carried on the track and capable of moving along the track. The bottom of the trolley has a drive roller for driving the conveyor belt on the trolley to rotate. The cylinder is connected to the friction part. When the trolley is required to sort the package into the grid, the cylinder drives the friction part to move in the direction close to the drive roller so that the friction part contacts the drive roller. When the trolley is not required to sort the package into the grid, the cylinder drives the friction part to move in the direction away from the drive roller so that the friction part is out of contact with the drive roller. Since the cylinder is always fixed, the grid PLC is directly connected to the cylinder through a cable to control the operation of the cylinder. In addition to the sorting machines that use cylinders to drive trolleys for sorting, there are also sorting machines on the market that use electric rollers to drive trolleys for sorting and electromagnetic clutches to drive trolleys for sorting. In these two types of sorting machines, the electric roller is installed on the trolley and moves continuously with the trolley, and the electromagnetic clutch is installed on the trolley and moves continuously with the trolley. The loop management PLC cannot communicate with the electric roller or electromagnetic clutch through cables. How to communicate with the electric roller or electromagnetic clutch has become the main problem faced by the distributed PLC control system when applied to sorting machines with electric rollers driving trolleys and electromagnetic clutches driving trolleys for sorting.

[0006] Therefore, an improved distributed PLC control system is urgently needed. Utility Model Content

[0007] (1) Technical issues to be resolved

[0008] In view of the problems existing in the above technologies, the present invention aims to solve them to at least a certain extent. To this end, the present invention aims to provide a PLC control system for a sorting machine, which is suitable for sorting machines that use electric rollers to drive trolleys for sorting, and sorting machines that use electromagnetic clutches to drive trolleys for sorting.

[0009] (2) Technical solution

[0010] In order to achieve the above-mentioned purpose, the main technical solutions adopted by this utility model include:

[0011] The utility model provides a PLC control system for a sorting machine. The circular trolley conveying line of the sorting machine is divided into a plurality of trolley partitions connected in sequence at the head and tail ends, and each trolley partition has a positive integer number of trolleys connected in sequence.

[0012] The sorting machine PLC control system includes a host computer and a trolley PLC. The trolley PLC corresponds to each trolley partition one by one. The trolley PLC is installed on any trolley in its corresponding trolley partition. The trolley PLC is connected to the driving element of each trolley in its corresponding trolley partition, and the trolley PLC is connected to the host computer via wireless communication.

[0013] Optionally, the sorting machine PLC control system further includes a loop line management PLC, an infeed table PLC and a slot PLC, and the loop line management PLC, the infeed table PLC and the slot PLC are all communicatively connected to the host computer.

[0014] Optionally, at least two of the host computer, the trolley PLC, the loop line management PLC, the infeed table PLC and the slot PLC are integrated to form a control device.

[0015] Optionally, the driving element of the trolley is an electric roller or an electromagnetic clutch.

[0016] Optionally, all infeeds of the sorting machine are divided into at least two infeed partitions arranged in sequence along the conveying direction of the trolley, each infeed partition has a positive integer number of infeeds, the infeed PLCs are set in one-to-one correspondence with the infeed partitions, and the infeed PLCs are communicatively connected with each infeed in its corresponding infeed partition.

[0017] Optionally, the number of the infeed station PLC is one, and the infeed station PLC is communicatively connected with all the infeed stations of the sorter.

[0018] Optionally, all the slots of the sorting machine are divided into at least two slot partitions arranged in sequence along the conveying direction of the trolley, each slot partition has a positive integer number of slots, the slot PLC is set in one-to-one correspondence with the slot partition, and the slot PLC is communicated with each slot in its corresponding slot partition.

[0019] Optionally, the number of the slot PLC is 1, and the slot PLC is communicatively connected to all the slots of the sorting machine.

[0020] Optionally, at least one trolley in the circular trolley conveyor line is provided with an identification device, at least one slot of the sorting machine is provided with a slot identity marker for identification by the identification device, and the identification device is communicatively connected to the trolley PLC.

[0021] Optionally, each trolley in the circular trolley conveyor line is provided with an identification device, and each slot of the sorting machine is provided with a slot identity marker for identification by the identification device.

[0022] Optionally, the car PLC is connected to the host computer via a Bluetooth module, a WiFi module or a Lora wireless gateway.

[0023] (3) Beneficial effects

[0024] The beneficial effects of the utility model are:

[0025] The sorting machine PLC control system provided by the present invention divides the trolley circular conveyor line into trolley zones and sets a trolley PLC for each trolley zone. The trolley PLC is communicatively connected with the driving element of each trolley in its corresponding trolley zone, and the trolley PLC is wirelessly connected with the host computer, thereby realizing the communication connection between the host computer and the trolley driving element (including the electric roller or the electromagnetic clutch). Therefore, the distributed PLC control architecture is applicable to the sorting machine in which the electric roller drives the trolley sorting and the electromagnetic clutch drives the trolley sorting by leveraging, thereby improving the execution accuracy of the sorting machine control system and providing system redundancy. The failure of some single PLCs will not affect the normal operation of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention is described with the help of the following drawings:

[0027] Figure 1 The figure is a network topology diagram of a sorting machine PLC control system according to a specific embodiment of the present utility model.

[0028] Reference numerals

[0029] 1: Host computer;

[0030] 2: Grid PLC;

[0031] 3: Induction table PLC;

[0032] 4: Loop management PLC;

[0033] 5: Trolley PLC. DETAILED DESCRIPTION

[0034] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation methods in conjunction with the accompanying drawings.

[0035] Example 1

[0036] like Figure 1 As shown, this embodiment provides a sorting machine PLC control system. The PLC control system is used to control a sorting machine. The sorting machine's circular trolley conveyor line is divided into multiple trolley partitions connected in sequence head to tail. That is, multiple trolley partitions connected in sequence head to tail form a circular trolley conveyor line, and each trolley partition has a positive integer number of trolleys. The PLC control system includes a host computer and a trolley PLC5. The trolley PLC5 is set in a one-to-one correspondence with the trolley partition. The trolley PLC5 is installed on any trolley in its corresponding trolley partition. The trolley PLC5 is communicatively connected to the drive element of each trolley in its corresponding trolley partition. The trolley PLC5 is wirelessly connected to the host computer.

[0037] The sorting machine PLC control system set up in this way divides the trolley circular conveyor line into trolley zones and sets a trolley PLC5 for each trolley zone. The trolley PLC5 is communicated with the driving element of each trolley in its corresponding trolley zone, and the trolley PLC5 is wirelessly communicated with the host computer, which can realize the communication connection between the host computer and the trolley driving element (including the electric roller or electromagnetic clutch), thereby making the distributed PLC control architecture suitable for sorting machines with electric rollers driving trolley sorting and sorting machines with electromagnetic clutches driving trolley sorting, improving the execution accuracy of the sorting machine control system and providing system redundancy. The failure of some single PLCs will not affect the normal operation of the entire system.

[0038] In this embodiment, each car partition has a positive integer number of cars, which means that each car partition has 1, 2, 3, 4... cars.

[0039] In this embodiment, the sorting machine PLC control system also includes a loop management PLC4, an infeed table PLC3, and a slot PLC2, all of which are connected to the host computer 1. In this way, a complete distributed PLC control architecture for the sorting machine is formed.

[0040] It should be noted that the driving element of the trolley specifically refers to the element on the trolley that drives the trolley conveyor belt. The sorting machine PLC control system provided in this embodiment is an improvement on the distributed PLC control architecture based on the Chinese invention patent application with publication number CN116520760A. The functions implemented by the infeed station PLC3, loop line management PLC4, grid opening PLC2, and host computer 1 in this utility model are the same or similar to the functions implemented by the infeed station PLC3, loop line management PLC4, grid opening PLC2, and host computer 1 in the Chinese utility model patent application with publication number CN116520760A, and will not be repeated here.

[0041] Preferably, at least one of the carts in the circular cart conveyor line is equipped with an identification device, and at least one slot of the sorter is provided with a slot identification marker for the identification device to recognize. The identification device is communicatively connected to the cart PLC5. This provides a structural basis for identifying the moving position of the circular cart conveyor line, thereby facilitating control of the docking of the target cart with the target slot.

[0042] Furthermore, preferably, each trolley in the circular trolley conveyor line is equipped with an identification device, and each slot of the sorter is provided with a slot identification marker for identification by the identification device. This provides a structural basis for the trolley PLC5 to identify the slot and, when the slot information identified by the trolley PLC5 matches the slot information of the trolley to be unloaded within the corresponding trolley zone, provides a structural basis for the trolley PLC to control the trolley to unload the package, thereby making the sorter PLC control system more responsive.

[0043] The identification device can be a through-beam sensor, a reflective sensor, an EDP camera, a barcode scanner, or the like. When the identification device is a through-beam sensor or a reflective sensor, the grid identification marker is a reflective sticker. When the identification device is an EDP camera or a barcode scanner, the grid identification marker is a QR code, barcode, or digital sticker. Using an identification device to identify grid openings is a relatively mature technology and will not be further described here.

[0044] In this embodiment, the supply table PLC3 and the host computer 1 can be connected by wired communication or wireless communication; the loop management PLC4 and the host computer 1 can be connected by wired communication or wireless communication; the grid PLC2 and the host computer 1 can be connected by wired communication or wireless communication; the trolley PLC5 and the driving elements of each trolley in its corresponding trolley partition can be connected by wired communication or wireless communication.

[0045] In this embodiment, the car PLC5 is connected to the host computer 1 through a Bluetooth module, a WiFi module or a Lora wireless gateway.

[0046] As an example, a sorting machine in which an electric roller drives a trolley for sorting, wherein the structure of the trolley refers to the Chinese utility model patent with an application date of November 10, 2023, an announcement date of August 16, 2024, and an announcement number of CN221543171U. The driving element of the trolley is the electric roller, and the trolley PLC5 is communicatively connected to the electric roller.

[0047] As an example, an electromagnetic clutch is used to drive a sorting trolley for sorting. The structure of the trolley can be found in the Chinese utility model patent application with application number 202410212049.7 and application date of February 27, 2024. The driving element of the trolley is an electromagnetic clutch, and the trolley PLC5 is communicatively connected to the electromagnetic clutch.

[0048] Preferably, the sorter is equipped with a loop management PLC4, an infeed PLC3 for each infeed, a slot PLC2 for every 28 to 34 slots, and each trolley zone has 40 to 65 trolleys. This PLC allocation facilitates the use of small and micro PLCs for the loop management PLC4, infeed PLC3, slot PLC2, and trolley PLC5, meeting processing requirements, improving system control accuracy, and reducing costs.

[0049] It should be noted that a programmable controller with less than 256 input / output (I / O) points and less than 2K steps of user program memory capacity is called a small PLC; among small PLCs, a PLC with less than 64 I / O points is also called a micro PLC.

[0050] More preferably, the loop management PLC 4 is a Schneider TM241 PLC, the infeed table PLC 3 is a Schneider TM221 PLC or TM200 PLC, the slot PLC 2 is a Schneider TM241 PLC, and the trolley PLC 5 is a Schneider TM241 PLC. In this way, different types of PLCs can be selected to process different levels of data based on processing requirements, ensuring overall system control accuracy while further reducing costs.

[0051] Further preferably, one slot PLC2 is configured for every 32 slots, and each trolley has 56 trolleys.

[0052] Optionally, all the infeed tables of the sorting machine are divided into at least two infeed table partitions arranged in sequence along the conveying direction of the trolley, each infeed table partition has a positive integer number of infeed tables, the infeed table PLC3 is set in a one-to-one correspondence with the infeed table partition, and the infeed table PLC3 is communicatively connected with each infeed table in its corresponding infeed table partition.

[0053] Optionally, the number of the slot PLC2 is 1, and the slot PLC2 is communicatively connected to all the slots of the sorting machine.

[0054] The PLC control system for the sorting machine provided by the utility model is applied to the sorting machine in which the electric roller drives the trolley for sorting and the electromagnetic clutch drives the trolley for sorting. It can improve the execution accuracy of the entire system, thereby increasing the loop speed to 4 meters per second and the sorting accuracy rate to one millionth.

[0055] Example 2

[0056] The main difference between this embodiment and embodiment 1 is:

[0057] The loop management PLC4 and the infeed table PLC3 are integrated to form a control device. The control device and the grid PLC2 are both connected to the host computer 1 for communication. The trolley PLC5 is connected to the host computer 1 for wireless communication.

[0058] The rest of the contents are the same as those in Example 1 and will not be repeated here.

[0059] Example 3

[0060] The main difference between this embodiment and embodiment 1 is:

[0061] The grid PLC2 and the infeed table PLC3 are integrated to form a control device. The control device and the loop management PLC4 are both connected to the host computer 1 for communication. The trolley PLC5 is connected to the host computer 1 for wireless communication.

[0062] The rest of the contents are the same as those in Example 1 and will not be repeated here.

[0063] Example 4

[0064] The main difference between this embodiment and embodiment 1 is:

[0065] The loop management PLC4 and the grid PLC2 are integrated to form a control device. The control device and the infeed table PLC3 are both connected to the host computer 1 for communication. The trolley PLC5 is connected to the host computer 1 for wireless communication.

[0066] The rest of the contents are the same as those in Example 1 and will not be repeated here.

[0067] Example 5

[0068] The main difference between this embodiment and embodiment 1 is:

[0069] The loop management PLC4, the grid PLC2 and the infeed table PLC3 are integrated to form a control device, the control device is connected to the host computer 1 for communication, and the trolley PLC5 is connected to the host computer 1 for wireless communication.

[0070] The rest of the contents are the same as those in Example 1 and will not be repeated here.

[0071] Example 6

[0072] The main difference between this embodiment and embodiment 1 is:

[0073] The trolley PLC5 and the infeed table PLC3 are integrated to form a control device, which is wirelessly connected to the host computer 1. The loop management PLC4 and the grid PLC2 are both connected to the host computer 1 for communication.

[0074] The rest of the contents are the same as those in Example 1 and will not be repeated here.

[0075] Example 7

[0076] The main difference between this embodiment and embodiment 1 is:

[0077] The host computer 1 and the loop management PLC4 are integrated to form a control device, the trolley PLC5 is wirelessly connected to the control device, and the infeed table PLC3 and the grid PLC2 are both connected to the control device.

[0078] The rest of the contents are the same as those in Example 1 and will not be repeated here.

[0079] In this utility model, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0080] In the present invention, unless otherwise expressly specified or limited, when a first feature is “above” or “below” a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, when a first feature is “above,” “above,” or “above” a second feature, it may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is “below,” “below,” or “below” a second feature, it may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0081] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0082] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are illustrative and cannot be understood as limitations on the present invention. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A sorting machine PLC control system, characterized in that: The circular trolley conveyor line of the sorting machine is divided into multiple trolley partitions connected in sequence from head to tail, and each trolley partition has a positive integer number of trolleys; The sorting machine PLC control system includes a host computer (1) and a trolley PLC (5). The trolley PLC (5) is arranged in a one-to-one correspondence with the trolley partition. The trolley PLC (5) is installed on any trolley in its corresponding trolley partition. The trolley PLC (5) is communicatively connected with a driving element of each trolley in its corresponding trolley partition. The trolley PLC (5) is wirelessly connected with the host computer (1).

2. The sorting machine PLC control system according to claim 1, characterized in that: It also includes a loop line management PLC (4), a feeding platform PLC (3) and a grid opening PLC (2). The loop line management PLC (4), the feeding platform PLC (3) and the grid opening PLC (2) are all connected to the host computer (1) for communication.

3. The sorting machine PLC control system according to claim 2, characterized in that: At least two of the host computer (1), the trolley PLC (5), the loop line management PLC (4), the infeed table PLC (3) and the slot PLC (2) are integrated to form a control device.

4. The sorting machine PLC control system according to claim 1, characterized in that: The driving element of the trolley is an electric roller or an electromagnetic clutch.

5. The sorting machine PLC control system according to claim 1, characterized in that: All the infeeds of the sorting machine are divided into at least two infeed partitions arranged in sequence along the conveying direction of the trolley, each infeed partition has a positive integer number of infeeds, an infeed PLC (3) is arranged in one-to-one correspondence with the infeed partition, and the infeed PLC (3) is communicatively connected with each infeed in its corresponding infeed partition.

6. The sorting machine PLC control system according to claim 1, characterized in that: The number of the infeed station PLC (3) is one, and the infeed station PLC (3) is communicatively connected with all the infeed stations of the sorting machine.

7. The sorting machine PLC control system according to claim 1, characterized in that: All the slots of the sorting machine are divided into at least two slot partitions arranged in sequence along the conveying direction of the trolley, each slot partition has a positive integer number of slots, the slot PLC (2) is set in a one-to-one correspondence with the slot partition, and the slot PLC (2) is communicatively connected with each slot in its corresponding slot partition.

8. The sorting machine PLC control system according to claim 1, characterized in that: The number of the slot PLC (2) is one, and the slot PLC (2) is connected to all slots of the sorting machine for communication.

9. The sorting machine PLC control system according to claim 1, characterized in that: At least one trolley in the circular trolley conveyor line is provided with an identification device, at least one slot of the sorting machine is provided with a slot identity marker for identification by the identification device, and the identification device is communicatively connected with the trolley PLC (5).

10. The sorting machine PLC control system according to claim 9, characterized in that: Each trolley in the circular trolley conveyor line is provided with an identification device, and each slot of the sorting machine is provided with a slot identity marker for identification by the identification device.

11. The sorting machine PLC control system according to claim 1, characterized in that: The car PLC (5) is connected to the host computer (1) via a Bluetooth module, a Wi-Fi module or a Lora wireless gateway.

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