Project 2 - Implement the Code for controlling the retraction and extension of Airplane’s landing gear
Output:
State Machine is initialized & Program is in Gear_Down_state & Light_Status:Green
Current State: GearDown
Enter the pilot's Lever Position, Squat Switch Status
0 0 (Lever = Raising,Squat Switch = Open)
Current State: Checking Before Take Off
Light State: Green
Current State: Checking Before Take Off
Enter the pilot's lever Position, Squat Switch Status and Hydraulic Mechanism Status:2 0 0
(Lever = Up, Squat status = Open, Hydraulic Pump = Working
Current State: Raising Gear
Light Status: Red
Direction valve Status: Up
Current State: Raising Gear
Enter the Limit Switch Status, Pilots Lever Status:
1 2 (Limit switch = Close, Lever = Up)
Current State: GearDown
Enter the pilot's Lever Position, Squat Switch Status
0 0 (Lever = Raising,Squat Switch = Open)
Current State: Checking Before Take Off
Light State: Green
Current State: Checking Before Take Off
Enter the pilot's lever Position, Squat Switch Status and Hydraulic Mechanism Status:2 0 0
(Lever = Up, Squat status = Open, Hydraulic Pump = Working
Current State: Raising Gear
Light Status: Red
Direction valve Status: Up
Current State: Raising Gear
Enter the Limit Switch Status, Pilots Lever Status:
1 2 (Limit switch = Close, Lever = Up)
Current State: Gear Up
Light State: Off
Hydraulic Control for landing Gear Status: Disabled
Current State: Gear Up
Airborne
Enter the Pilot's lever Position 1 (Lever = Falling)
Current State: Checking Before Landing
Light Status: Red
Hydraulic Control for Landing Gear Status: Enabled
Current State: Checking Before Landing
Enter the Pilot's Lever Position and HydraulicMechanism Status:
3 0 (Lever = Down, Hydraulic Pump = Working)
Current State: Lowering Gear
Light State: Green
Direction Valve Status: Down
Current State: Lowering Gear
Enter the limit Switch Status, pilot's lever Position
0 3 (Limit switch = 0, Lever Position = Down)
Current State: GearDown
Light Status: GreenHydraulic Control for Landing Gear Status: Enabled
Current State: GearDown
Current State: GearDown
Light Status: GreenHydraulic Control for Landing Gear Status: Enabled
Current State: GearDown
Landed Successfully!
C program:
#include <stdio.h>
void LoweringGear(void);
void CheckingBeforeTakeoff(void);
void CheckingBeforeLanding(void);
void RaisingGear(void);
void GearDown(void);
void GearUp(void);
void InitiateStateMachine(void);
//define the State_Type variable with the different enumerated values
//GEAR_DOWN=0, CHECK_BEFORE_TAKEOFF=1, RAISING_GEAR=2, GEAR_UP=3, CHECK_BEFORE_LANDING=4, LOWERING_GEAR=5
typedef enum State
{
GEAR_DOWN,
CHECK_BEFORE_TAKEOFF,
RAISING_GEAR,
GEAR_UP,
CHECK_BEFORE_LANDING,
LOWERING_GEAR
}State_Type;
//define the Switch_Status variable with the different enumerated values
//Open=0, Close=1
typedef enum Switch
{
Open,
Close
}Switch_Status;
//define the Pilot_Lever_Status variable with the different enumerated values
//Raising=0, Falling=1, UP=2, DOWN=3
typedef enum Pilot_Lever
{
Raising,
Falling,
UP,
DOWN
}Pilot_Lever_Status;
//define the Hydraulic_Mechanism_Status variable with the different enumerated values
//Working=0, Malfunctioning=1
typedef enum Hydraulic_Mechanism
{
Working,
Malfunctioning
}Hydraulic_Mechanism_Status;
//Defining enum data type as static to indicate to the compiler to retain the values of the previous state
//Defining enum data type as volatile qualifier the compiler of changing values across iterations
static volatile Switch_Status Squat_Switch;
static volatile Switch_Status limit_switch;
static volatile Pilot_Lever_Status pilot_lever;
static volatile Hydraulic_Mechanism_Status hydraulic_mechanism;
State_Type current_state; //auto variable
//Define structure
typedef struct
{
char* current_state_indication;
char* light_status;
char* direction_valve_status;
char* hydraulic_pump_control_status;
char* gas_pressurized_spring_status[2];
}State_Table;
State_Table State_Machine[6]={
{"GearDown","Green","Down","Enabled",0,0},
{"Checking Before Take Off","Green","Down","Enabled",0,0},
{"Raising Gear","Red","Up","Enabled",{"Disabled","Enabled"}},
{"Gear Up","Off","Null","Disabled",0,0},
{"Checking Before Landing","Red","Down","Enabled",0,0},
{"Lowering Gear","Green","Down","Enabled",{"Disabled","Enabled"}}
};
//function pointer
static void (*state_table[])(void) = {GearDown,CheckingBeforeTakeoff, RaisingGear, GearUp, CheckingBeforeLanding, LoweringGear};
int main()
{
InitiateStateMachine();//Calling the function
while(1)
{
state_table[current_state]();
}
}
void LoweringGear()
{
current_state = LOWERING_GEAR;
printf("\n Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("\n Enter the limit Switch Status,pilot's lever Position");//switch status and lever position
fflush(stdout);
scanf("%d %d", &limit_switch, &pilot_lever);
if(limit_switch == Close && pilot_lever == Raising )
{
current_state=CHECK_BEFORE_TAKEOFF;
printf("\n Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("\nLight Status: %s",State_Machine[current_state].light_status);
}
if(limit_switch == Open && pilot_lever == DOWN)
{
current_state = GEAR_DOWN;
printf("\n Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("\nLight Status: %s",State_Machine[current_state].light_status);
printf("Hydraulic Control for Landing Gear Status:%s\n",State_Machine[current_state].hydraulic_pump_control_status);
}
else
{
LoweringGear();
}
}
//Defining the function to indicate Checking_Before_Takeoff
void CheckingBeforeTakeoff()
{
current_state = CHECK_BEFORE_TAKEOFF;
printf("\n Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("\n Enter the pilot's lever Position, Squat Switch Status and Hydraulic Mechanism Status:");
fflush(stdout);
scanf("%d %d %d",&pilot_lever, &Squat_Switch, &hydraulic_mechanism);
if(pilot_lever == Falling ||Squat_Switch == Close)
{
GearDown();
}
else if(pilot_lever==UP && Squat_Switch==Open && hydraulic_mechanism==Working)
{
current_state=RAISING_GEAR;
printf("\n Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("\nLight Status: %s\n",State_Machine[current_state].light_status);
printf("Direction valve Status:%s\n\n",State_Machine[current_state].direction_valve_status);
}
else if (pilot_lever== UP && Squat_Switch == Open && hydraulic_mechanism ==Malfunctioning)
{printf("Light Status:%s\n", State_Machine[current_state].light_status);
printf("Direction Valve Status:%s\n",State_Machine[current_state].direction_valve_status);
printf("Gas Pressurized Spring System Status:%s\n",State_Machine[current_state].gas_pressurized_spring_status[hydraulic_mechanism]);
}
}
//Defining the function to indicate Checking_Before_Landing
void CheckingBeforeLanding()
{
current_state = CHECK_BEFORE_LANDING;
printf("\n Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("\n Enter the Pilot's Lever Position and HydraulicMechanism Status:\n");
fflush(stdout);
scanf("%d %d",&pilot_lever, &hydraulic_mechanism);
if(pilot_lever == DOWN && hydraulic_mechanism == Working)
{
current_state = LOWERING_GEAR;
printf("\n Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("\nLight State: %s\n",State_Machine[current_state].light_status);
printf("Direction Valve Status:%s\n",State_Machine[current_state].direction_valve_status);
}
else if(pilot_lever== DOWN && hydraulic_mechanism == Malfunctioning)
{
current_state = LOWERING_GEAR;
printf("\n Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("\nLight Status: %s\n",State_Machine[current_state].light_status);
printf("Direction Valve Status:%s\n",State_Machine[current_state].direction_valve_status);
printf("Gas Pressurized Spring System Status:%s\n",State_Machine[current_state].gas_pressurized_spring_status[hydraulic_mechanism]);
}
if(pilot_lever == (UP||Raising||Falling))
{
CheckingBeforeLanding();
}
}
//Defining the function to indicate Raising Gear
void RaisingGear()
{
current_state = RAISING_GEAR;
printf("\nCurrent State:%s\n",State_Machine[current_state].current_state_indication);
printf("\n Enter the Limit Switch Status,Pilots Lever Status:\n");
fflush(stdout);
scanf("%d %d",&limit_switch, &pilot_lever);
if(pilot_lever == Falling && limit_switch == Open)
{
current_state=CHECK_BEFORE_LANDING;
printf("\n Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("\nLight State: %s\n",State_Machine[current_state].light_status);
printf("Hydraulic Control for Landing Gear State:%s\n",State_Machine[current_state].hydraulic_pump_control_status);
}
else if(limit_switch == Close && pilot_lever == UP)
{
current_state=GEAR_UP;
printf("\n Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("\n Light State: %s\n",State_Machine[current_state].light_status);
printf("\n Hydraulic Control for landing Gear Status:%s\n",State_Machine[current_state].hydraulic_pump_control_status);
}
else
{
RaisingGear();
}
}
//Defining the function to indicate Gear Down
void GearDown()
{
current_state = GEAR_DOWN;
printf("\nCurrent State:%s\n",State_Machine[current_state].current_state_indication);
printf("\n Enter the pilot's Lever Position, Squat Switch Status \n");
fflush(stdout);
scanf("%d %d",&pilot_lever, &Squat_Switch);
if(pilot_lever == Raising && Squat_Switch == Open)
{
current_state=CHECK_BEFORE_TAKEOFF;
printf("\n Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("\nLight State: %s\n",State_Machine[current_state].light_status);
}
else
{
GearDown();
}
}
//Defining the function
void InitiateStateMachine()
{
current_state = GEAR_DOWN;
printf("\n State Machine is initialized & Program is in Gear_Down_state & Light_Status:%s\n",State_Machine[current_state].light_status);
}
//Defining the function to indicate Gear Up
void GearUp()
{
current_state = GEAR_UP;
printf("\n Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("\n Enter the Pilot's lever Position ");
fflush(stdout);
scanf("%d",&pilot_lever);
if(pilot_lever == Falling)
{
current_state=CHECK_BEFORE_LANDING;
printf("\n Current State:%s\n",State_Machine[current_state].current_state_indication);
printf("\nLight Status: %s\n",State_Machine[current_state].light_status);
printf("Hydraulic Control for Landing Gear Status:%s\n",State_Machine[current_state].hydraulic_pump_control_status);
}
else
{
GearUp();
}
}