ABSTRACT:
This project proposes a means of intelligence for an RF based automated storage and retrieval system (ASRS). Main objective of this project is to provide intelligence in the existing Warehouse Management System (WMS), which utilizes man power, on-paper data recording and non- intelligent machines during the operation. So the essence of this project is to implement intelligence in controlling the ASRS with RF module. ASRS having Programmable Logic Controller, which controls and coordinates the movement and performance of ASRS. Intelligence with ASRS is provided for storing or retrieving appropriate amount of load according to the input from users. This new means of control is emulated using a PLC emulator and SCADA.
Keywords - RF module, Warehouse Management System, SCADA.
INTRODUCTION:
PLC technology is rapidly evolving and is playing an increasing role in the automated industrial environment. An automated storage and retrieval system consists of a variety of computer controlled methods for automatically placing and retrieving loads from specific storage locations. ASRS are typically used in applications where there is a very high volume of loads being moved in and out of storage since storage density is important due to space constraints. To avoid expensive damages to the load accuracy is also important. So the ASRS is enhanced with RFID transmitter and tags in the racks for centralized control from PC. And also it makes the centralized control affordable by providing the facility of selecting appropriate quantity.
In modern manufacturing enterprise, auto warehouse with Automated Storage and Retrieval System (ASRS) of Material Handling System (MHS) plays an important role for storing and retrieving of products and parts to cope with fierce global competition and rapid market changes. It allows full-pallet load and layered-pallet inventory to be quickly, safely and precisely within a warehouse environment and thus rapid configuration to the right storage. The control of ASRS can be man- aboard or remote control. In remote controlled ASRS, the system controller is a standalone PC. The software resident on PC will take care of bin/part number. According to the instruction from operator the ASRS store/retrieve load.
LITERATURE SURVEY:
ASRS use the concepts of high rise, high density storage of items with a manually handling of crane system. The material is stored in standard size bins, crates or pallets, which are stacked into high rise racks, with multiple levels. The length of the rack is 100 -150 meters and height is 8 -15m. ASRS have the aisles, in each aisle there is a stacker crane which picks up the load from a station and stores in a location by operators physical interaction and also take the load out from the racks. That is they can place or retrieve loads. ASRS are generally supported on a track and ceiling guided at the top by guide rails or channels to ensure accurate vertical alignment. A pickup and delivery station can be a simple elevated structural pedestal to accommodate the product of load. They are designed to convey, rotate or elevate loads if required. Practically the human operator of the ASRS is provided the cabin in stacker crane, where operator does all the tasks. Person has to sit in the cabin and manually operate the crane. A well trained person for operating the crane is allotted and whenever any load to be moved in or out, operator has to move the crane at required height, length, left, right. The operation and physical verification of operating conditions must be checked regularly. All safety measures for the manual operations are made with care.
PROPOSED IDEA:
This project aims to develop the functionality of remote control for ASRS by RF module such that it stores or retrieves according to the input at the user end. In remote controlled ASRS, software is stored in PC and communicated with the ASRS through wired LAN. After verifying the available database in the system controller, the command has to ply over the wired LAN means to the PLC and as per the commands received by the PLC, control actions have to be performed, and the database has updated continuously. The flexibility of ASRS is enhanced using RF module. ASRS having RF module and racks in WMS having the RFID tags.
Also the exact quantity of input can be selected by the operator using command in the system. Intelligence in ASRS is provided to store or retrieve exact amount of material through selection. Instead of aisle, ASRS is developed with arm for picking or dropping the material.
ASRS DESCRIPTION:
ASRS is a computerized and used for handling the material which is at a height. The system performs the automated stores operation. The system offers effective utilization of space, since the floor space is costly in industrial environment. Minimum man power, computerized store/retrieval operation. Control to the ASRS from pc is provided through wired LAN. The software of ASRS can handle the material management systems and also management information systems (MIS) for effective monitoring and control.
They are divided into four major parts high rise storage racks, crane, storage bins and controllers.
High Rise Storage Racks:
For effective utilization of vertical space, generally the materials are stored in high columns. The racks are designed in these columns, where they are made up of steels and can be installed quickly. Two rails for moving ASRS over the racks, in bottom and top. Bottom fixed with respect to storage racks and top rail for movement between two rows. RFID tags are positioned in front of every rack.
Crane:
This is a twin column structure, handles store/retrieval operations. The fork which extends left/right side or for dropping material into bin. For emergencies, in case the automation is failed operator can manually operate from the cabin.
Storage Bins:
Containers used for store/ retrieval in ASRS. The material or raw products like bolts, pipes etc will be dropped are taken out from these bins. So the bins should be of dust free and correct dimensions are used. RFID readers are fixed in the front end of the bins.
Controllers:
Practically to replace the human operator on the stacker crane and the entire task the operator would do, is automated by micro PLC. It is programmed to execute commands received from system controller, by moving the stacker crane for the desired operations, and giving a feedback to the PC based system controller. The stacker carne controller is connected to several sensors and limit switches to get the physical inputs. The output goes to the operator’s panel for activation of limit switches. The sequencing of operations like inputs from sensors and limit switches are programmed in the PLC. And also the driver and relay operations for rotate, elevate, stretch of arm developed in ASRS also programmed in PLC.
According to the command from microcontroller the PLC make arm for ASRS to respond. ARM processor is used with another support as a controller for ASRS.
