Robot Project by Ahmad Shtaiyat Supervised by Dr. Salem Al-Agtash

Robot: An electromechanical device which is capable of reacting in some way to its environment, and take autonomous decisions or actions in order to achieve a specific task My robot operation : It will use Ultrasonic sensors to detect the distances, and enable it to move in many degrees then go to the distance if there is no wall or barrier,and the distance larger than 20 cm, if it become less than 20 after movement then stop, detect the distance in the other directions then choose the best direction and move.

Is this Robot Mobile Robot ? It has Mechnical parts ( DC motors, wheels, chasse, H-bridge, sensor, servo motor …), and has Microcontroller (Arduino ). Microcontroller receive the information from the sensor, then according to this information it will determine the distance, then change the servo angle, then force the sensor to recompute the distance, then determine the direction of movement. Force the DC-motor to move So this Robot function autonomously, it has its own decision according to the environment sensing, this decision change with these information directly, it doesn’t keep doing the same task every time. According to these four points its mobile Robot not just industrial one.

Is this Robot Real time system ? 1. Perception : We sensing the information from the environment using ultrasonic sensor, which send ultrasound waves with specific predetermined angle, these wave will be reflected from the surface when collide with it, then the sensor give us the trigger time (sending time ), and the echo time ( receiving time ). 2. Localization : The ultrasonic.h library give us a function Ranging(CM) ; which determine the distance according to the equation : distance = speed *time. time = echo time - trigger time. speed of ultrasonic wave constant in space = 345 m/sec. this distance represent our location with reference to the barrier.

3. Cognition : According to this distance the microcontroller will determine the path. a. while ( distance >= 20 ) : move forward, So our path will be forward. b. while ( distance < 20 ) : change the angle to left, Then recalculate the distance. change the angle to right, Then recalculate the distance. move in the direction of the larger distance. still doing this until the distance become larger than 20 cm then go to a and move forward.

4. Motion control : After the Robot move forward, during walking there is a closed loop, which will keep taking the measuring distance, still compared it with 20 cm, if it become less than it, stop then repeat the step 3-b. Sensing value, or process value Set point (20 CM) Controlled system Microcontroller

Applications : Work as cleaning machine. By adding small camera and register device, we can use it to collect information ( pictures and sounds) for locations which we can't reach. By replace the DC-motors by stepper motors, we can use it for planting seeds.

Disturbances : The major problem is when we used it outside the house, is that the wind, because its weight is too small.

The code : As the following code there are four tasks : Sensing the distance. Changing the angle. Determine the direction. Control the motion And they operate concurrently

#include unsigned int Time; unsigned int distance; unsigned int left1 ; unsigned int left2 ; unsigned int right1 ; unsigned int right2 ; int IN1 = 3; int IN2 = 5; int IN3 = 6; int IN4 = 9; int sensor_reading = 0; Servo myservo; int A = 0; Ultrasonic ultrasonic (12, 13); void setup () { myservo.attach(10);

pinMode(IN1, OUTPUT); pinMode(IN4, OUTPUT); pinMode(IN2, OUTPUT); pinMode(IN3, OUTPUT); pinMode(A0, INPUT); Serial.println("Robot initialize"); } void forword() { digitalWrite(IN1, LOW); digitalWrite(IN2, HIGH); digitalWrite(IN3, LOW); digitalWrite(IN4, HIGH); delay(50); } void background() { digitalWrite(IN1, HIGH); digitalWrite(IN2, LOW); digitalWrite(IN3, HIGH); digitalWrite(IN4, LOW); delay(50); }

void right() { digitalWrite(IN1, HIGH); digitalWrite(IN2, LOW); digitalWrite(IN3, LOW); digitalWrite(IN4, HIGH); delay(50);} void left(){ digitalWrite(IN1, LOW); digitalWrite(IN2, HIGH); digitalWrite(IN3, HIGH); digitalWrite(IN4, LOW); delay(50);} void STOP() { digitalWrite(IN1, LOW); digitalWrite(IN2, LOW); digitalWrite(IN3, LOW); digitalWrite(IN4, LOW); delay(50);}

void loop () { myservo.write(90); delay(15) ; sensor_reading = ultrasonic.Ranging(CM); Serial.print("Distance= "); Serial.println(sensor_reading); while (sensor_reading > 20) { forword(); Serial.print("Distance= "); Serial.println(sensor_reading); Serial.println("Forward,distance>20"); } while (sensor_reading < 20) { STOP(); myservo.write(165); left1 = ultrasonic.Ranging(CM); delay(1000); myservo.write(135); left2 = ultrasonic.Ranging(CM);

delay(1000); if ( (left1 - left2) >= 0); else left1 = left2 ; delay(50); delay(1000); myservo.write(0); right1 = ultrasonic.Ranging(CM); delay(1000); myservo.write(45); right2 = ultrasonic.Ranging(CM); if ( (right1 - right2) >= 0); else right1 = right2 ; if ( (left1 - right1) >= 0) left(); else right(); sensor_reading = ultrasonic.Ranging(CM); } }

Robot parts: Frame / Platform : I will use Aluminum or Plastics because these materials are light weight,moderately and easy to work can also be found at Home Hardware or I can use Re-purposed Materials: There are a lot of items around the house which can be turned into a robot frame.

Motors : Continuous Rotation Servos ( Servos already have all of the control circuitry built in and are easy to control; they have 3 wires which represent signal, Voltage, and ground. By pulsing the signal line you can go forward, stop, or backward. ), or Gear motors ( Gear motors will require additional control circuitry (normally an H-bridge) to allow forward and reverse motion and in some cases braking. Gear motors can provide great flexibility but usually cost more compared to servos)

Wheels : we can use wheels from old toys or buy wheels from a shop or air-filled wheels for model aircraft are very easy to use. Note that often wheels from toys don’t have the right hole size, so we might have to do some customizing to get them to fit the motor

Power : Batteries ( we need to decide what type of batteries to use. It can quickly become very expensive replacing non-rechargeable batteries. Rechargeable batteries are really the best and we need corresponding charger to charge them with, though there are a number of different types to choose from.), and Power supply ( We need a voltage regulator to drop the voltage from the battery to the 5 volts needed by the Microcontroller and other parts of the Brain for the robot )

Microcontroller or brain : There are three different types of them, Atom,PIC16F876, Arduino, I will use Arduino : Arduino: The “newest” contender on the market is Arduino; it’s open source and there are a LOT of different versions. It has become wildly popular with the robotics community and seems to be incredibly versatile.

Motor driver L298 It's used to control the movement of two motors with maximum current of two ampere for each of them

Sensors : there is a lot of different sensors according to their types, manufacture and functionality, but for my robot I need sensors to sense distance there a lot of types of them like laser, infrared and ultrasonic, I will chose the ultrasonic sensor : Ultrasonic Range Finders: Ultrasonic range finders use acoustics to measure the time between when a signal is sent versus when its echo is received back. Ultrasonic range finders can measure a range of distances.

The circuit :. Servo : DC motors : Ultrasonic sensor :

Thanks