Auto Fuel Supply Controller for starter engine for aircraft

GUIDE

Mrs. HEMAVATHI N VASST.PROF ECE DEPARTMENT

GROUP

SARLIDHA D SHILPA B N PADMA K N SWETHA J

Fuel system is one of the most important subsystems of aircraft and engine control unit which forms the base for fuel control.

Fuel flow of a starter engine varies with ambient conditions, such as temperature pressure and the amount of fuel flow to the engine is different at various altitudes.

In this project, we developed a program using C and implement it on a MICROCONTROLLER system to control the flow of fuel for the starter engine of an aircraft.

ABSTRACT

Our aim is to develop an open loop system which responds to the subsequent changes in the system environment such as speed, temperature and pressure

Sensors are used to sense these ambient conditions, and gives to the microcontroller as input and rotates the stepper motor in desired direction

Continue….

Many variations of aircraft engine starting have been used since the wright brothers made their first powered flight in 1903.

The methods used have been designed for weight saving, simplicity of operation and reliability.

Early piston engines were started by hand, with geared hand starting, electrical and cartridge-operated systems for larger engines being developed between the wars.

INTRODUCTION

Gas turbine aircraft engines such as turbojets, turboshafts and turbofans often use air/pneumatic starting with the use of bleed air from auxiliary power units (APUs) now seen as a common starting method.

Here fuel flow is controlled based on the temperature and the pressure.

Continue….

FUNCTIONAL BLOCK DIAGRAM

Microcontroller PIC16F877A

Temperature sensor LM35

  Stepper motordriver

Stepper Motor

Signal conditioner

Force resistive sensor 555 timer

As speed input

16*2 LCD

Start key

The program is written in C language

Then the program is compiled

If there is no error then the program is downloaded on PICKIT 2

And then downloaded on microcontroller

5v power supply is given to the microcontroller

All the hardware’s supply is 5v expect for the stepper motor which is 12v

The pressure is varied by pressing the sensor & temperature is varied using a lighter

Depending upon these parameter the stepper motor is rotated through stepper motor driver.

1. Microcontroller PIC16F877A

Microcontroller PIC16F877A is one of the PIC Micro Family microcontroller which is popular at this moment, start from beginner until all professionals

It uses FLASH memory technology so that can be write-erase until thousand times. 

HARDWARE REQUIRMENT

PIC16F877A perfectly fits many uses, from automotive industries and controlling home appliances to industrial instruments, remote sensors, electrical door locks and safety devices.

It is also ideal for smart cards as well as for battery supplied devices because of its low power consumption

Stepper motor is a brushless DC electric motor  that divides a full rotation into a number of equal steps.

The motor's position can then be commanded to move and hold at one of these steps without any feedback sensor (an open loop controller), as long as the motor is carefully sized to the application.

STEPPER MOTOR

TWO PHASE STEPPER MOTOR

There are two basic winding arrangements for the electromagnetic coils in a two phase stepper motor: bipolar and unipolar.

LM35 is a precision IC temperature sensor with its output proportional to the temperature (in 0C).

The sensor circuitry is sealed and therefore it is not subjected to oxidation and other processes.

TEMPERATURE SENSOR LM35

With LM35, temperature can be measured more accurately than with a thermistor.

 It also possess low self heating and does not cause more than 0.1 oC temperature rise in still air.    

The operating temperature range is from -55°C to 150°C.

The output voltage varies by 10mV in response to every oC rise/fall in ambient temperature, i.e., its scale factor is 0.01V/ oC.

 

FORCE RESISTIVE SENSOR

A force-sensing resistor is a material whose resistance changes when a force or pressure is applied.

They are also known as "force-sensitive resistor"

Force-sensing resistors are commonly used to create pressure-sensing "buttons" and have applications in many fields

Applying a force to the surface of the sensing film causes particles to touch the conducting electrodes, changing the resistance of the film

 Compared to other force sensors, the advantages of FSRs are their size (thickness typically less than 0.5 mm), low cost and good shock resistance.

 

LCD (Liquid Crystal Display) screen is an electronic display module and find a wide range of applications.

A 16x2 LCD display is very basic module and is very commonly used in various devices and circuits.

2 LINE LCD

These modules are preferred over seven segments and other multi segment LEDs

A 16x2 LCD means it can display 16 characters per line and there are 2 such lines.

 This LCD has two registers, namely, Command and Data.

The command register stores the command instructions given to the LCD to do a predefined task like initializing it, clearing its screen, setting the cursor position, controlling display etc.

The data register stores the data to be displayed on the LCD.

MPLABX Microchip IDE XC8 “C” compiler

SOFTWARE REQUIRMENTS

MPLABX IDE is a software program that is used to develop applications for Microchip microcontrollers and digital signal controllers.

This development tool is called an Integrated Development Environment, or IDE, because it provides a single integrated “environment” to develop code for embedded microcontrollers

MPLAB XC Compilers produce highly optimized code

We have developed a program in C and implemented it on a MICROCONTROLLER system to control the flow of the fuel into the starter engine of an aircraft .

System responds to the subsequent changes oil disturbances in the system environment such as speed, temperature and pressure

Sensors are used to sense these ambient conditions, and gives the corresponding output

CONCLUSION

[1] Kassa Kian, J.G; Wolf, H, -C; Miller, J M; Hurton, C.J.(1996) “Automotive electrical systems area 2005-IEEE spectrum”. IEEE spectrum(IEEE) 33(8); 22. doi: 10.1109/6.511737.

[2] Gunston Bill(1989). World encyclopedia of Aero Engine.Cambridge, England; Patrick Stephens Limited. P.26.ISBNI-85260-163-9.

[3] F.Herntz and E.Zabler( “Problems in the applications of sensors in motor vehicles ”) Sens.rol.3 PP.327-341, 1982/83.

[4] D.Dlugos (“Wergand effect sensors theory and application”) sensor PP-32-34 may 1998.

REFERENCE

REFERENCE HAL

THANK YOU