Automation fault detection in automobile using PLC.

                                                                                                                       

Automobiles is a wide system consisting of internal engines and machineries. In automobiles, there are varied chances of faults in the engines due to the changing temperature, speed, etc., but detecting of such faults can be laborious and time consuming. So using a PLC instead can ease the process. A Programmable Logic Controller (PLC) is a digital computer used for automation of electromechanical processes. Unlike general purpose computers PLC is designed for multiple inputs and outputs arrangement, extended temperature ranges, immunity to electrical noise, and resistance to vibrations and impacts. A PLC is an example of real time system since output results must be produced in response to input conditions within a bound time.

For every PLC controlled system, the larger percentage of its faults are commonly in the actuators and sensors as well as its wiring and not in its PLC. The faults inside PLC are most likely in the output input power supply or channels rather than the CPU itself. There can be two probable cases:

1.              If any output device that fails of turning on even the LED output is on. If you are testing the output PLC voltage and it indicates normality, then its fault may be the device fault or wiring fault. Then, if you will check the device voltage and indicates normality, then its fault is on the device.

2.              Failure of FED input for illuminating as required can be because:

·      The device input it not properly operating

·      The input device is not properly powered

·      Improper wiring connection to input module or input module or LED is defective.

Most PLC are providing built- in procedures for fault analysis that carries out self- testing as well as display fault code. Together with brief messages that can also be translated through looking up codes in the list for giving the fault’s sources and the possible methods of recovery.

The probable detection methods for identifying motor faults are:

·      Chemical analysis

·      Current measurement

·      Voltage measurement

·      Partial discharge method

·      Temperature measurement

·      Vibration monitoring

·      Radio frequency emission monitoring

·      Speed measurement

·      Acoustic noise measurement

 

Though induction machines can be reliable, they also face some undesirable stress that causes of failure in some faults. There are some researches that studied different machine faults which involves conclusions that machine failure includes installation and mechanical faults.

PLC can also be programmed to activate, sense and control the industrial equipment. So, PLC is incorporating number of I/O point that allows the electrical signal for interfacing. Output and input components of a certain process are connected on the PLC; control programs are loaded to PLC memory.

Different results showed that reliable PLC-based system for protection that includes operators and variable of IM has been developed. Using PLC can definitely reduce the efforts and time required to detect faults in automobiles.