PLC Control System Design for Egg Carton Unloader Han-yu ZHAO 1, Zhi-jun HUO 2, Xiao-jiang LAI 3 and Cun-xiang LIU 1,*

Size: px

Start display at page:

Download "PLC Control System Design for Egg Carton Unloader Han-yu ZHAO 1, Zhi-jun HUO 2, Xiao-jiang LAI 3 and Cun-xiang LIU 1,*"

Ethel Farmer
6 years ago
Views:

1 2017 2nd International Conference on Electrical and Electronics: Techniques and Applications (EETA 2017) ISBN: PLC Control System Design for Egg Carton Unloader Han-yu ZHAO 1, Zhi-jun HUO 2, Xiao-jiang LAI 3 and Cun-xiang LIU 1,* 1 College of Mechanical and Electrical Engineering, Agricultural University of Henan, Zhengzhou, , China 2 Henan Mechanical and Electrical Vocational College, Zhengzhou, , China 3 Shenyang Machine Tool(Group) Research & Design Institute Co., Ltd. Shanghai Branch, Shanghai, , China *Corresponding author Keywords: Egg carton unloader, PLC, Control system. Abstract. An egg carton unloader is a device used to feed eggs loaded in cartons to the clean egg production line, and mainly includes three major components: loaded carton conveying mechanism, carton unloading mechanism, and egg feeding platform. In this paper, based on the mechanical and pneumatic systems designed for the device, the Siemens S PLC is selected for control system development for the egg carton unloader, distribution design and program control flow chart design for I/O point, realization of automation control of the carton conveying mechanism, carton unloading mechanism and egg feeding platform. It features high reliability and high cost effectiveness. Introduction As China s economy developed, people s living standards rose and the daily diet s demand for eggs increased, China s egg yield leaped to number one in the world in 1985, and continued to stay ahead. According to statistical data from 2015 from the National Bureau of Statistics, China s egg yield was up to million tons in 2015 [1]. However, the eggs consumed in China are mainly those purchased from vegetable markets, are never treated in any way, and are often stained with feathers, blood or even excrement. Such eggs are neither good looking nor healthful. Owing to people s emphasis on food safety, large breeding enterprises have begun to introduce foreign devices for producing clean eggs and selling such eggs in supermarkets. The so-called clean eggs refer to fresh and shelled eggs which have been processed by technologies such as rinsing, drying, membrane spraying, grading, code spurting, carton loading and freshness-maintaining packaging [2]. The increase of consumption of clean eggs and the improvement of labor costs are bound to bring a large demand for clean egg production equipment. There is a certain difference between China s breeding scale and foreign breeding scale. In general, foreign breeding scale is large, up to several hundred thousand or even million; in general, however, China s breeding scale is small, and only a few poultry farmers breeding scale is up to a hundred thousand [3]. Therefore, introducing foreign clean egg production equipment does not suit China s breeding status quo. In China, large breeding enterprises usually take the lead and purchase eggs of smaller poultry farmers nearby for producing clean eggs for which they need to use a carton unloader. The so-called carton unloader is a device used to feed eggs loaded in cartons to the clean egg production line. The device has the following roles: replacing manual carton unloading or unloading with the aid of simple auxiliary tools, improving production efficiency, and reducing labor intensity. In this paper, it is proposed to provide an introduction of the developed control system for automatic carton unloaders. Structure And Oeration Of Carton Unloader Structure of Carton Unloader The carton unloader is a device used in the first working procedure of the clean egg production line, and as an important device, its production efficiency and reliability will directly affect the 160

2 performance of the whole clean egg production line. Therefore, in order to realize reliability and high efficiency of carton unloading, the carton unloader is composed of the following three parts: (1) carton conveying mechanism, which is mainly composed of a chain conveyor and carton collection device and is used to convey loaded cartons to the carton unloading device for carton unloading and collect unloaded cartons; (2) carton unloading mechanism, which is the core device of the carton unloader and is mainly composed of a guiding cylinder, oscillating cylinder, carton compressing mechanism and egg suction mechanism and is mainly used to suck up the eggs in the cartons and place them on the egg feeding platform so as to realize egg carton unloading; (3) egg feeding platform, which is used to convey eggs placed by carton unloading forwards to other working procedure mainly through one belt conveyor [4]. The structural representation of the carton unloader is shown in Figure I. 1(Egg feeding platform) 2(Egg ) 3(Oscillating cylinder) 4(Connection block) 5(Egg suction mechanism 2) 6(Control cabinet) 7(Carton compressing mechanism) 8( Chain conveyor belt) 9(Guiding cylinder) 10(Rack) Figure I. Structurl represennation of automatic egg carton unloader. Operation of Carton Unloader This device sucks up eggs in loaded cartons conveyed by the chain conveyor belt through the carton unloading structure, rotates them and places them on the egg feeding platform. The specific operation process of the carton unloader which satisfies the technical requirements of carton unloading is as follows: the chain conveyor conveys loaded cartons placed manually (mechanically) on the chain conveyor belt to the carton unloading position; the position detection sensor detects them to see whether they are in place and then sends a signal to the PLC; the PLC sends a signal to the magnetic valve to compress cartons downwards in the compressing mechanism with the cylinder; the egg suction mechanism right above moves downwards through the guiding cylinder and sucks up the eggs with a vacuum; at the same time, the suction cup of the egg suction mechanism on the egg feeding platform is connected with air and puts the eggs down; then the magnetic valve of the guiding cylinder inverts; the egg suction mechanism rises and rotates after reaching its position; at the same time, the chain conveyor belt moves forward for a distance of one carton, the carton compressing cylinder mechanism compresses the cartons with the cylinder; the magnetic valve of the cylinder inverts again; the egg suction mechanism drops and completes the egg suction and placing actions; then the next egg unloading cycle starts [5]. The egg carton unloading process flow diagram is shown in Figure II. 161

3 Figure II. Egg carton unloading process flow diagram. Figure III. Control schematic diagram. Control System Design The designed egg carton unloader, with intricate structure and complex actions, requires accurate coordination of actions among devices, controls many signals, and is applicable to magneto electric situations. Therefore, programmable logic controller (PLC) is selected as its control core. This is because PLC has advantages such as high reliability and strong capacity of resisting disturbance, and requires little system design, programming, installation and debugging. Therefore, the PLC is widely applied to automatic control systems of various mechanical devices and production processes. 162

4 Figure IV. Control Flow Chart. 163

5 Table I. I/O address assignment. Input Output Element Addr Function Element name Addres Function name ess s Button SB1 I0.0 Device start Magnetic valve YA1 Q0.0 Egg connected to vacuum Button SB2 I0.1 Device stop Magnetic valve YA2 Q0.1 Egg connected to vacuum Button SB3 I0.2 Device pause Magnetic valve YA3 Q0.2 Egg combination 1 connected to vacuum Button SB4 I0.3 Device reset Magnetic valve YA4 Q0.3 Egg combination 2 connected to vacuum Change-over switch SA I0.4 Manual/automatic selection: manual Magnetic valve YA5 Q0.4 Egg combination 3 connected to vacuum Change-over switch SA I0.5 Manual/automatic selection: automatic Magnetic valve YA6 Q0.5 Egg combination 4 connected to vacuum Button SB5 I0.6 Guiding cylinder rise Magnetic valve YA7 Q1.0 Egg combination 5 connected to vacuum Button SB6 I0.7 Guiding cylinder drop Magnetic valve YA8 Q1.1 Egg combination 1 connected to vacuum Button SB7 I1.0 Rotating cylinder forwards Magnetic valve YA9 Q1.2 Egg combination 2 connected to vacuum Button SB8 I1.1 Rotating cylinder backwards Magnetic valve YA10 Q1.3 Egg combination 3 connected to vacuum Button SB9 I1.2 Egg suction mechanism 1 connected to vacuum Magnetic valve YA11 Q1.4 Egg combination 4 connected to vacuum Button SB10 I1.3 Egg suction mechanism 1 connected to air Magnetic valve YA12 Q1.5 Egg combination 5 connected to vacuum Button SB11 I1.4 Egg suction mechanism Magnetic valve Q1.6 Oscillating cylinder forwards 2 connected to vacuum YA13 Button SB12 I1.5 Egg suction mechanism Magnetic valve Q1.7 Oscillating cylinder backwards 2 connected to air YA14 Magnetic I1.6 Guiding cylinder - upper Magnetic valve Q2.0 Carton compressing cylinder rise valve BG1 limit YA15 Magnetic I1.7 Guiding cylinder - lower Magnetic valve Q2.1 Carton compressing cylinder drop valve BG2 limit YA16 Magnetic I2.0 Carton compressing Magnetic valve Q2.2 Guiding cylinder rise valve BG3 cylinder - upper limit YA17 Magnetic I2.1 Carton compressing Magnetic valve Q2.3 Guiding cylinder drop valve BG4 cylinder - lower limit YA18 Magnetic I2.2 Rotating cylinder - 0 Running status Q2.4 Running (green) valve BG5 position indicator lamp H1 Magnetic I2.3 Rotating cylinder Running status Q2.5 Pause (yellow) valve BG6 position indicator lamp H2 Optoelectron ic switch GB1 I2.4 Detection of carton position 1 Running status indicator lamp H3 Q2.6 Failure (red) Optoelectron ic switch GB2 switch KP1 switch KP2 switch KP3 switch KP4 switch KP5 switch KP6 I2.5 Detection of carton position 2 I2.6 Detection of of combination 1 in egg I2.7 Detection of of combination 2 in egg I3.0 Detection of of combination 3 in egg I3.1 Detection of of combination 4 in egg I3.2 Detection of of combination 5 in egg I3.3 Detection of of combination 1 in egg Buzzer Q2.7 Alarm Contactor 1 Q3.0 Asynchronous motor of egg feeding platform Contactor 2 Q3.1 Asynchronous motor of carton conveyor belt 164

6 switch KP7 switch KP8 switch KP9 switch KP10 I3.4 Detection of of combination 2 in egg I3.5 Detection of of combination 3 in egg I3.6 Detection of of combination 4 in egg I3.7 Detection of of combination 5 in egg Control System Composition The main task of a control system for an egg carton unloader is to control the various parts of the egg carton unloader according to the rhythm and work flow of the clean egg production line. The main actions to be controlled include: start and stop of the egg feeding platform; start and in-place stop of the carton conveyor belt; and the rise, drop, rotation, suction and putting-down of the egg suction mechanism. To complete the above control requirements, the control system of the device mainly involves the PLC, magnet switch, optoelectronic switch, magnetic valve and asynchronous motor[6][7]. The control schematic diagram is shown in Figure III. PLC Selection The operation method of the egg carton unloader is divided into two modes: manual and automatic continuous. The device has 32 input points and 24 output points in total. In view of reliability and economy, the Siemens S type PLC is selected because this type of PLC features compact design, low price and an instruction set with powerful functions, which is able to provide communication and solutions for various technological tasks, and is especially suitable for meeting the demands of entirely different automatic control in multiple applications. The CPU 1212C DC/DC/DC is selected as the central processing unit (CPU) module, and the two-figure input/output extension module SM1223 is added, which is able to provide 40 input points and 38 output points in total[8]. I/O Address Assignment I/O address assignment of the egg carton unloader is based on the S PLC input and output characteristics and control requirements. Specific assignments are shown in Table I. Program Flow Chart The egg carton unloader requires close and accurate coordination between its various complex actions. Therefore, during control system design, the PLC is taken as the control core; the two-figure input/output extension module SM1223 is added; multiple magnetic switches and optoelectronic switches are used for position detection in order to realize inversion control or actions of elements such as magnetic valves, ensuring the reliability of the device. The control system of the device sets two operation modes: manual and automatic, which considers the actual situation of the device in debugging and repair during the design process. The control flow chart is shown in Fig. IV [9]. Conclusion As people s demand for clean eggs has increased, labor costs have continued to rise, and clean egg production enterprises demands for automatic clean egg production lines have become increasingly large, the egg carton unloader has become one key part of a clean egg production line. It can not only rapidly and accurately move eggs to the egg feeding platform, and but also can adjust the speed of various actions to adapt to the rhythm of the clean egg production line, significantly improving efficiency. In this paper, a control system is designed based on the working principles of the egg carton unloader and research on the designed mechanical and pneumatic systems; PLC 165

7 selection and I/O point assignment are conducted; and a program control flow chart is drawn. The developed egg carton unloader features low price and high reliability, and is bound to be widely applied to automatic clean egg production lines. References [1] [2] S.-F. Yang, M.-H. Ma, K.-M. Zhong, The Importance of Key Techniques of Clean Egg Production and Consumption in Our Country, Modern Food Science and Technology, 2007, 23(3): [3] L. Lv, R.-F. Wu, Egg Industry Development Current Situation and Consumption Trend at Home and Abroad, China Poultry, 2015, 37(1): [4] H.-Y. Zhao, W.-H. Huang, C.-X. Liu, Design of Pneu matic System in Unloading Eggs Machine, Chinese Hydraulics & Pneumatics, 2016, (4): [5] L.-J. Li, Manual of Selection and Design in Packaging Machinery, Beijing: Chemical Industry Press, [6] Y.-Q. Wang, Control System Design of the Manipulator Based on PLC, Chinese Hydraulics & Pneumatics, 2011, (9): [7] X.-J. Wang, B. Hu, Application of PLC and Touch-screen in the Multi-DOF Pneumatic Manipulator, Modular Machine Tool & Automatic Manufaturing Technique, 2016, (3): 58-60, 63. [8] F.-Y. Li, Introduction to Illustration of Siemens S PLC to Practice,Beijing: Mechanical Industry Press, [9] H.-B. Liu, Siemens S PLC Programming and Application, Beijing: Mechanical Industry Press,

An Indian Journal FULL PAPER ABSTRACT KEYWORDS. Trade Science Inc.

An Indian Journal FULL PAPER ABSTRACT KEYWORDS. Trade Science Inc. [Type text] [Type text] [Type text] ISSN : 0974-7435 Volume 10 Issue 13 BioTechnology 2014 An Indian Journal FULL PAPER BTAIJ, 10(13), 2014 [7435-7441] Desalination sewage treatment based on PLC automatic