Project 2 - Implement the Code for controlling the retraction and extension of Airplane’s landing gear

Implement the code for controlling the retraction and extensioin of Airplane's Landing gear.

Introduction:

An airplne has three gears for landing:

Nose Gear

• Left Gear

Right Gear

The hydraulic pump are used for exerting pressure to the gears to bring it down or pull it up and that pump is electrically driven.

Limit switches: Every leg of the gear has one limit switch.

Squat switch: only nose gear have squat switch to determine whether the airplan is in ground or not.

Switch state

State of Gears

Limit Switch CLOSED

Gear is UP

Limit Switch OPENED

Gear is DOWN

Switch State

Squat Switch CLOSED

Squat Switch OPENED

State of Airplane

Airplane is grounded and gears are locked Airplane is taking off/ landing/ airborne

A direction valve is controlled by software to allow the hydraulic pressure to either raise or lower the landing gear

Status of Direction Valve

Direction valve = Down

Direction valve = Up

Control of hydraulic pump for the landing gear part is disabled

States of landing gear

(Gear Down) (Parked at bay or Landed)

Raising Gear (Taking Off)

Gear up (Airborne)

Direction valve = down

Lowering Gear (Landing)

Input for the direction valve:

Pilot's Lever State

Lever UP

Lever Down

Direction Valve State

Direction valve = Up

Direction valve Down

Pilot's Lever State

Lever Rising Edge

Lever Falling Edge

Light Status

Red

Red

Every gear has one light. According to the state of the gear, color of the light is changing.

Landing Gear State

Light Status

Gear is up

OFF

Gear is down

Green

Gear in transit

Red

By incorperating all these constraints we can come to result as shown below