自動(dòng)化立體倉(cāng)庫(kù)系統(tǒng)設(shè)計(jì)--堆垛機(jī)及其防墜落裝置及其安全系統(tǒng)、水平運(yùn)行裝置、機(jī)架設(shè)計(jì)含6張CAD圖
自動(dòng)化立體倉(cāng)庫(kù)系統(tǒng)設(shè)計(jì)--堆垛機(jī)及其防墜落裝置及其安全系統(tǒng)、水平運(yùn)行裝置、機(jī)架設(shè)計(jì)含6張CAD圖,自動(dòng)化,立體倉(cāng)庫(kù),系統(tǒng),設(shè)計(jì),堆垛,及其,墜落,裝置,安全,水平,運(yùn)行,機(jī)架,CAD
Development of a Small Scale Material Handling Machine for Automated Storage and Retrieval
System (ASRS)
Saif Ullah Iqbal, C. B. Yeo and UmarNirmal
ABSTRAC
The current works deals with the design and development of an Automated Storage and Retrieval System (ASRS) machine for Flexible Manufacturing System (FMS). The work involved investigating ASRS machine features and operating procedures, evaluating related hardware, software and communication modules for the machine. The work explored on the different options of hardware and software modules offered in the current market and further selected the suitable one for the ASRS machine development. Several design considerations and the limitations faced during the process of the project development and implementation are given. Arduino was used as the coding system for the Arduino UNO board while stainless steel 305 and aluminium was used as the main frame in fabricating the ASRS machine. Lastly, a final working prototype of a fully-developed ASRS machine with dimensions of: 80cm by 73cm by 94cm (length by width by height) is presented.
Keywords: Small scale; material handling; ASRS; FMS; prototype; pick and place machine; Arduino UNO; stainless steel 304; aluminium.
INTRODUCTION
An ASRS involves a selection of computer- controlled structures in order to robotically place and retrieve loads from well-defined stocked places. Their fundamental preferences over usual (pickers to quantities) storeroom systems are vast space practice, decreased work charges, short recovery periods and an improvement in controlling the inventory of stocks. Automated Storage and Retrieval Systems (ASRSs) are generally utilized in stockrooms and primarily in distribution centres in most part of the world. There is a good ground for the idea that this type of automation drive to keep (or even escalate) their wide application in the likely future, along with the discussed model industry trends and certainly all the above benefits. There has been much advancement in Automated Storage and Retrieval technology in the last forty years and the ASRS number is predicted to grow rapidly in the next few decades. The progressing multiplication of item assortment perceptible in numerous businesses expands the assortment of stock-keeping-units (SKUs) to be taken care of in a normal distribution centre. For example, the plant in Dingolfing of German car manufacturer BMW gets material in excess of 13,000 compartments conveyed by around 600 providers on over 400 trucks every day. Taking care of such an enormous measure of parts by solid in-house coordination forms appears to be not really reasonable without mechanized warehousing [1-2]. An ASRS stores stock all the supplementary thickly and, in this manner, dispenses with the requirement for such energy to cool, heat, ventilator, and lighting abundance of storing space. One of the Material Handling Industry of America (MIH, 2009), the food business sets aside to 30% cooling cost in chilled distribution centres put on Automated Storage and Retrieval Systems [3-4]. With a maturing society in many created nations and an expanding authoritative weight (e.g., EU Machinery Directive, 2006/42/EC, 89/391/EEC, Occupational Safety and Health Act) ergonomic perspectives need extraordinary thought for storing. The above statistics should be a wake-up call for industries to consider ways they can make employee safety significant in the workplace. One of the solutions is to introduce automation. By automating manual repetitive tasks, workers can be reassigned to safer areas where they can exercise imagination, adaptability and decision-making skills. As noted by the World Economic Forum, robots are perfect
for physically demanding or dangerous tasks for humans to carry out and, economically, they can work around the clock at a lower cost than human workers among which, the Automated Storage and Retrieval Systems appears to be favourable [5].
Generally, an Automated Storage and Retrieval System is programmed for managing pallets without the interference of a human worker, consequently, the structure is called fully automated. Both in manufacture and supply, locations of Automated Storage and Retrieval Systems are used for putting products (e.g., raw materials or partially finished products) in storage, and for retrieving those products back from storage to complete the task. In designing an Automated Storage and Retrieval System, numerous physical plan and control issues must be tended to in the correct method to completely exploit every one of its professionals. The ASRS will hone the maker's opposition as ASRS can diminish the inventories and process duration, and ideally use the capital and work [6]. Fundamentally, an ASRS system consists of storage shelves, the control system, storage and retrieval column, human user interface and deposit and withdraw bay. An item would be placed and retrieved from the storage shelves by mean of the storage and retrieval column machine where it is to retrieve or store the objects in the storage system. The automation system generally consists of a conveyor system as automation for storage and retrieval machines and frame structure as automation pathway [7]. The automation systems will in charge of vertically, inside/outside and horizontally moving the storage and retrieval mechanism that performs the storage or retrieval course. Therefore, to control the system, The Graphical User Interface is the platform for the user to command a process to either store or retrieve the selected boxes placed on the withdraw and deposit bay or sort the boxes in the shelves of the complete rack itself. The material picking module of ASRS is to meet the targeted user specific operational requirement. After the design phase, the Storage and Retrieval mechanism will be fabricated and used to conduct the storage and retrieve process in an ASRS. The material picking module of ASRS is intended to meet the focused-on consumer- explicit operational necessity. This module consists of a racks structure along with the storage and retrieval column to conduct the storage and retrieval commands by means of ASRS.
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Most of the Automated Storage and Retrieval System accessible in the market is normally high-priced or large in size and it is just focusing on the large enterprise [8,9]. For the medium and small organizations, the issue of the floor plan and economic report frustrate them to execute the Automated Storage and Retrieval System into the operational organization. Mistakes may occur unintentionally loading and retrieving objects at the exclusive area and notice the things in racking can now and then be difficult. About these issues, an Automated Storage and Retrieval System is planned to suit the operational prerequisite of the little and medium firms, just as to diminish the error rates and expanded reliability quality while saving labor costs and floor space [10,11]. Therefore, the current works is aimed to design and develop a state-of-the-art automated storage and retrieval system. The machine will be linked with a developed GUI program to allow users to interact with the machine in a ?user-friendly? manner.
1. METHODOLOGY
1.1 Hardware
In this section, there are sections in assembly movements, selected components design stability and the design itself and its fabrication process, these subparts with its own specific function for serving its own operational purposes. The general assembly of these subparts will able to achieve the project objectives to perform the storage and retrieval operations precisely.
1.1.1 Structure assembly materials
The structure material for this module is chosen as Stainless Steel 305 and Aluminium 5083, while Aluminium is typically not as strong as Stainless Steel and Stainless Steel has excellent corrosion resistance for two reasons. First, Stainless Steel has chromium added which forms an invisible corrosion resistant film around the Steel. Second, it is non-porous which increases the corrosion resistance. The Stainless Steel are used specifically for load carrying segments, and the Aluminium are used just for coupling or to maintain the overall project weight as compare to Stainless Steel, Aluminium is far way lighter compared to stainless steel. The Stainless Steel 305 rectangular tube (5cm x 2.4cm) and (2.5cm x 1.2cm) are used for Shelve frame base and shelve module structure respectively and aluminium plate 5083 are used for coupling of different assemblies.
1.1.2 Information on components used
Following are the hardware components are used for the current work and their brief descriptions.
1.1.2.1 Linear screw
According to Thomson Industries [12-14], the thread of Linear Screw uses a helix angle to make the linear motion. The coefficient of friction between the nut and the screw are aligned with the performance of a lead screw depends heavily on, which relies on the material utilized for the nut and screw. For this project, we used Linear Screw for the three-dimensional shuttle in x, y and z axes so to move the assembly of Storage and Retrieval to left-right, up-down and forward- backward.
1.1.2.2 Hard chrome piston rod
The hard chromium piston rods are produced by Suzhou Weipeng Precision Machinery Co., Ltd. is in Suzhou with JIS S45C material, where the poles initially experience exactness processing and preparing, and are then put through guard surface chromium treatment, permitting a surface accuracy dimension of f7, and a surface hardness coming to HV800 least and up, which help to enhance wear opposition and help to broaden the existence cycle of the bars, hence making a good motion. The module is dual- mounted with the chrome piston rods, for frictionless slider motion of Storage and Retrieval assembly in x, y and z axes. The pair of rods helps the assembly to move precisely in a specific direction using Linear Ball Bearing.
1.1.2.3 Stainless steel support rod
The Stainless Steel rod is installed as a structural support of Z column (Crane) which is fitted vertically, on top with Aluminium plate of Motor base [15].
1.1.2.4 Linear ball bushings
Linear bushing with mechanism utilizes the rolling motion of ball features. As linear motion is achieved with a simple mechanism, the linear bushing can be used in a wide variety of uses, including carriage, food treating, and semiconductor manufacturing tools. Linear slide bushings use a round channel for the guiding axis, causing in space savings, which allows for compacted schemes. The Low Friction, channel
surface is precision ground. Since the contact surface between the ball features and the raceway surface is reduced, linear slide bushing bearings provide low friction related to other linear motion tools. In this module we are using two sizes of Linear Ball Bushings, i.e.,16mm and 20mm for the for the hard chrome plated rods helping the assembly motion [16].
1.1.2.5 Mounting bolts
There are different types and sizes of Allen key and Hex Head bolts used in this project. Further, it is categorized as Button Head Cap, Socket Head Cap, Counter Sunk and Hex Head Cap. In total, the module has 43 Button head cap, 21 Counter Sunk Head, 16 Socket Head Cap and 8 Double Ended bolts of Allen Key plus 4 Hex Head Cap bolts are fitted. So as the net total 92 bolts are fixed in the whole module. Refer Appendix A for more information on the bolds used.
1.1.2.6 Levelling bottom pad
The module is fitted with four Levelling Pads while levelling feet are almost always solid metal; levelling pads usually have a rubber or urethane pad at the bottom, which will provide grip to keep the machine from moving and can help stabilize cabinetry, shelving, machinery and more. Levelling pads may be used instead of levelling feet when a floor may be scarred or marred by a steel foot.
1.1.2.7 Electrical / electronic housing
An electrical box is a cabinet for either electrical or electronic kit to mount controls, knobs, and displays and to stop electrical shockwave to kit users and keep the subjects from the surroundings; This housing is made from Acrylic Sheet 25cm by 15cm, Three parallel plates are connected through Long bolt of 12mm leaving a gap inside of 8cm and 12.5cm respectively, creating a design of open shelves The Bottom shelf is assigned for power supply and the top shelf is to mount the control Motor Drivers, Arduino UNO board and Interface Circuit between the limit Switches and Arduino UNO Board. The top shelf sheet is mounted with Safety Switch for any dangerous situation.
1.1.2.8 Drag chain
Cable carriers, correspondingly well-known as drag chains, drive chains, or cable chains
depending on the producer, are guides planned to surround and guide bendable electrical cables and hydraulic or pneumatic hoses connected to moving robotic equipment. In this module we are using three sizes of Drag Chains 7 x 7 mm, 10 x
15 mm and 15 x 30 mm. For the x-axis, the cables are using 7 x 7 mm size of Drag chain with a length of 450 mm, for z-axis the cable is guided into 10x15 mm Drag Chain with a length of 730 mm whereas for y-axis the cable is hoses into 15x30 mm Drag Chain with a length of 990 mm. The y-axis is carrying all the cables leading from x and z axes where it is acting as a bottleneck to main controller housing. Refer Appendix B for more information on the drag chains used.
1.1.2.9 Coupling
It is a component used for bonding two different rods/shafts composed by their split ends in order to conduct power. Generally, it does not usually let disconnection of shafts through operation, though there are torque controlling couplings in which it slips-up or detaches when some torque perimeter is surpassed. There is only single coupling mounted on z-axis between the motor and lead screw, which was fabricated from Stainless Steel rod of diameter 25mm using a Turning and Milling Machine.
1.1.2.10 Wiring spiral duct
Wire duct application is same as drag chain where it differs only in a way that it?s flexible and can be shaped in any form; generally, it is a kind of cable management product that permits the users to route bulky packs of cabling in a relaxed & organized style. The project wires are bed in with 700 mm and 400mm long size with a diameter of 15mm and 8mm respectively.
1.1.2.11 Frame structure
The Frame is designed with 3 x 3 column and rows. The rows and columns are designed in such a way to achieve the diagonal movement demonstration plus reduction half right angle triangle based to reduce cost and achieve the demonstration objectives. However, the shelf is rack railed with Stainless Steel rail size 10mm wide enough to handle heavy loaded items. The base of the frame is made of Stainless Steel rectangular Tube 503 of size 50 mm x 240 mm, the base dimensions are 600 mm x 600 mm on top of which the shelves are fabricated with Stainless Steel rectangular tube 503 of size 250
mm x 120 mm with each shelf internal dimensions of, i.e.,(L x W x H) 200 mm x 180 mm x 150 mm = 5.4 x 106 mm3. Multiplying this with 8 shelves 43.2 106 mm3 of Storage Capacity, whereas the last shelve at column 3 row 2 is Pick and Place shelf and could be connected to a conveyor or human manual loading. Choosing the Stainless Steel as fabrication for the frame was to make it strong enough to handle fairly heavy loads. Due to the storage and retrieval process, this material has a longer life compare to other options. Fig. 1 illustrates the CAD model of the frame structure design.
Fig. 1. Frame structure design using CAD
1.2 Assembly Motion
The Module assembly is designed in such a way so the motion of the mechanism could be smooth and frictionless. The machine has three assembly motions categorized as coordinated system x, y, and z. The x-axis coordinate
assembly is responsible to store and retrieve the packages from the racks by moving back and forth; c.f. Fig. 2. The assembly maximum moving zone is 360mm. The x-axis is mounted through linear ball bushing with z-axis to lift up or down the mechanism of Storage and Retrieval.
The z-axis coordinates assembly is responsible to move the Storage and Retrieval mechanism up and down to a specific row by following the specific command from the user input; c.f. Fig. 3. The maximum travel area for this axis is 640 mm. This assembly is mounted to y-axis assembly.
The y-axis is the core assembly and it is mounted with frame base to move the other two assemblies in specified directions; the z-axis is mounted with y-axis by linear ball bushings; c.f. Fig. 4. This axis has the maximum allowed movement zone of 650mm either to move the full assemblies together towards left or right to specify the column numbers.
1.3 Design and Fabrication
In designing such a module the first thing to be taken care of is listing down the material required, cut into the exact size required and then assembling them either by mean of welding or bolt joint. Second and most important, the orientation of the tubes to design the frame in such a way to get a higher moment of inertia, as a higher moment of inertia means higher resistance to bending. Following Fig. 4, the orientation of the fabricated tube suggests the greatest moment of inertia in the Iz-axis compared to the other two axes. The following section will provide brief information on the design and development of the module.
Fig. 2. Assemble
Fig. 3. Assemble motion at the Z-Axis
motion at the X-Axis
Fig. 4. Assemble motion at the Y-Axis
1.3.1 Frame and base design
The frame consists of base and shelves column, i.e., nine racks, the 2D dimensions of the base is shown in Fig. 6 respectively. The rectangular frame comprises a rectangular tube of size 50mm x 240mm, each side the tube was cut at 45-degree angle of length 600mm making four equal length bars and brazing them with tungsten torch wire with a cumulative length of 2400mm providing a great solidity to the whole framework.
Remark: All dimensions in mm
Fig. 6. Base dimensions
1.3.2 Rack design and 3D dimensions
On top of the base frame, the shelves are designed with a rectangular tube of dimensions 250 mm x 120 mm making of three columns, Fig. 7 shows the size of each column tube, i.e., the first column height is 600mm consuming four equal lengths of 600mm rectangular tubes, the second column consists of two rectangular tubes of height of 450mm welded with base and the third column approaches the height of 300mm fitted with two rectangular tubes attached from the base. The racks are made with a gap 150mm in height and 200mm in length. The width of each column is 180mm resulting in eight storage and retrieval for storage and one shelf for deposit and pick up bay. With shelves, the Y-axis assembly holder in welded as the core moment of other assemblies. The end plates are mounted on sides of the base frame to hold the two-piston chrome-plated rods with the linear screw, on the left plate a drive motor is connected to move the assembly towards left or right. Fig. 8 shows the base with shelves and Y-axis assembly holder. They are connected with Y, Z and X axes assembly mechanisms, following the same structure method for x assembly. For z holder,
the end supporting plated is connected with Y- axis assembly and the other end in supported by an Aluminium plate with a support of Stainless Steel rod including the linear screw and two piston chrome plated rods.
1.3.3 Control system: Electrical works
· Drive motors: In this module, there are three stepper motors, i.e., NEMA 23, NEMA 23 and NEMA 34, used by X, Y and Z axes respectively. The motors are installed at the end of each assembly to mo
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