PLC Based Control Of Resistance Spot Welding Operation

Abstract

The automotive industries started the development of the Programmable Logic Controller (PLC) primarily because of massive rewiring that has to be done every time when a model change occurred. PLC modules are much easier to change than the relay panels. This advantage is reflected in the cost of installing and operating the PLC instead of traditional relay system. A PLC is a “digitally operating system” designed for use in an industrial environment , which uses a programmable memory for its internal operation of user orientated instructions and for implementing specific function such as Logic, Sequencing , timing , counting, and arithmetic. PLC controls digital or analog input and outputs in the various types of machines or processes. This major project presents the simulation, design, PLC based control of sequence of operation of welding cycle. This project is divided into four sections. First, a brief introduction about PLC, methods of control and interfacing circuit used in PLC. The introduction to the design of the control scheme employed with the basic block diagram of Resistance Spot Welding and the functioning is presented. Thirdly, the design and development of the control software algorithm is dealt with. Finally, the conclusions is drawn along with its working and future improvements.