EEL 5666C - Intelligent Machine Design Lab Final report

Transcription

1 EEL 5666C - Intelligent Machine Design Lab Final report Date: 04/21/14 Student Name: Shaoyi SHI Robot Name: Alin ssytom@hotmail.com TA: Instructors: Josh Weaver A. Antonio Arroyo Eric M. Schwartz 1

2 Table of Contents Abstract... 3 Executive Summary... 3 Introduction... 4 Integrated System... 5 Mobile Platform... 7 Actuation & Sensors... 8 Behaviors... 9 Conclusion... 9 Appendices References

3 Abstract Alin is the name of a friend of mine, it s a sound control robot based on frequency identification. It looks like a space shuttle, with self-designed structure make of wood by T-tech. The robot is driven by two wheels, it can wonder around and avoid obstacles, and when it hears the special musical note from my flute, it will be under my control, react correspondingly to different notes played by my flute. Executive Summary Alin is designed based on ArduinoMega2560 with various sensors and parts, a digital frequency meter for sound signal is made with Arduino and MIC, also a self-made repeating crossbow. The design, layout, parts and behaviors of Alin are shown in this report. And it looks like this. 3

4 The first picture above is the first design drawn with SolidWorks, the second picture is how it really looks, I made several changes including sensors, geometry of kit locations of parts. Introduction The idea for Alin is inspired by snake charmer, who uses their musical instrument to tame and control the snake. So I decided to use my Bawu (Chinese instrument similar to flute) to control my snake which is actually my robot. I also made a weapon for it, a Zhu Ge repeating crossbow, an invention in Three Kingdoms period(ad ), one of the longest-lived mechanical weapons. I made this with wood board by myself. 4

5 Integrated System Alin has two type of sensors: sonar sensors and digital frequency meter module. And two types of actuators: motors and repeating crossbow. Sonar sensors are fixed at the front, and will return the distances between my robot and obstacles. DC motors with a motor controller are used to drive the robot. Obstacle avoidance My robot can wonder without hit any obstacles, this is achieved by sonar sensors and motors. the principle my this system is shown blow: 5

6 Digital Frequency Meter I made this meter based on comparative method, the basic idea for digital frequency is shown below: First the incoming signal is modified by weaken or magnified and shape to square wave. Then use the gating signal to create an interval. Oscillator is used to generate signal with known frequency, this signal is pre-scaled with time base circuit. A counter is used to count the number of pulses from this pre-scaled signal during the interval created by gating signal, since the frequency of the pre-scaled signal is known, the time period during the gating signal can be obtained. Controlling circuit is used to control the system and calculate the time period. I made this system with Arduino and MIC. The systems works like this: first the MIC will transfer incoming sound signal to electrical signal, then this signal is magnified by Triode magnifying circuit. The MIC is connected to Arduino with digital PIN, which will modify the signal from sin wave to square wave: 6

7 I use Arduino s attachinterrupt() function as gating signal, which will go to ISR when voltage of PIN rise and fall, thus the interval created by this gating signal equals to the period of wave of incoming signal. The processor of Arduino, ATmega2560 is used as Oscillator, and its frequency is 16MHz. TCCR1B is used as prescaler and TCNT1, a 16bit counter is used as the counter, these are all integrated in ArduinoMEGA2560. The period of incoming signal can be calculated by following equation: f = reding of TCNT1 prescaler The frequency of the musical notes I used obtained by my digital frequency meter are: Because my MIC is of kind of low sensitivity, I placed a loudspeaker on my robot, and connected it to my cellphone with blue-tooth. So I can play my flute to my cellphone and transfer this sound to my MIC. I use these notes as commands and my robot will react correspondingly to each of these notes. The whole system is shown as below: The main problem I had was the noise from the background will sometimes interfere this process, my solution was to use times so that my robot only response to sound of certain frequency and lasts for longer than about 0.3s. Mobile Platform The kit of my robot consists of two pieces of space shuttle shape wood. The sonar sensors are placed in the front. Two wheels with motors are placed in the two sides at back. Arduino board, motor controller and loudspeaker are inside the robot. The crossbow with servo and the MIC are fixed on the top. And 5 LED are used to show commands. All the sensors, servo and the motor controller are connected to Arduino board, and the motors are then connected to the wheels. 7

8 Actuation & Sensors The robot is driven by 2 300RPM 6V 0.45A High Torque Mini Electric DC Geared Motors and wheel: The Zhu Ge repeating crossbow is driven by RHX Micro 9g Mini Servo: Three Zitrades Module HC-SR04 Ultrasonic Distance Sensor are used to get distances thus achieve obstacle avoidance: 8

9 The incoming sound signal is transferred to electrical signal with ZITRADES High Sensibility microphone sensor module fit for KY-037 ARDUINO with 2 output: Behaviors Alin will first wonder around and avoid obstacles, and when play my flute with that certain note for twice, it will hear my command and stop moving, mean well the red led will light up showing that it s now tamed by me. Then I can give commands including go ahead, go back, turn left, turn right and shoot by playing different notes. If I play that certain note for twice again, my robot will be freed and start to wonder again. Conclusion Alin was completed on time and employs the behaviors proposed. I can be a snake charmer with my flute and control it. And for most cases the noise form background will not bother my control over it. Through this class, I got basic understanding and hands on experience for embedded design, as well as the complete process for making a simple robot. And I always think it necessary for engineering students to know basic ideas for ECE staffs. I also want to say thanks to Dr. Arroyo, Dr. Schwartz and DR. Jadiaz, and all the TAs. Especially to josh, he was like my babysitter. 9

10 Appendices #include <fix_fft.h> #include <Servo.h> Servo myservo; #define echo1 47 #define echo2 49 #define echo3 51 #define trig 45 #define Lmotor1 6 #define Lmotor2 3 #define Rmotor1 4 #define Rmotor2 5 #define lled 41 #define rled 12 #define fled 53 #define bled 7 #define sled 13 short distance1,distance2,distance3,mind; int divider[6]={0, 1, 8, 64, 256, 1024; int prescaler = 5; double count = 0; double middle = 0, freq; char x = 0; int sonarcount =0; int shootcount=0 ; int backcount=0; int leftcount=0; int rightcount=0; int frontcount=0; int changecount=0; ISR(TIMER1_OVF_vect)//call this interrupt service routine when overflows { if (prescaler < 4) { prescaler++; 10

11 void interrupt() { if (!x)//include x=0,null and so on { count = TCNT1;//16 bit register that saves counter value TCNT1 = 0x000;//set to 0 TCCR1B = prescaler;//set how to divide system clock attachinterrupt(0, interrupt, FALLING); // interrupt pin0, actually digital pin2 else { middle = TCNT1; attachinterrupt(0, interrupt, RISING); x = ~x; void goahead(int a){ digitalwrite(lmotor1, HIGH); digitalwrite(lmotor2, LOW); digitalwrite(rmotor1, LOW); digitalwrite(rmotor2, HIGH); delay(a); digitalwrite(lmotor1, LOW); digitalwrite(lmotor2, LOW); digitalwrite(rmotor1, LOW); digitalwrite(rmotor2, LOW); void justgo(){ digitalwrite(lmotor1, HIGH); digitalwrite(lmotor2, LOW); digitalwrite(rmotor1, LOW); digitalwrite(rmotor2, HIGH); 11

12 void turnleft(int a){ digitalwrite(lmotor1, LOW); digitalwrite(lmotor2, HIGH); digitalwrite(rmotor1, LOW); digitalwrite(rmotor2, HIGH); delay(a); digitalwrite(lmotor1, LOW); digitalwrite(lmotor2, LOW); digitalwrite(rmotor1, LOW); digitalwrite(rmotor2, LOW); void turnright(int a){ digitalwrite(lmotor1, HIGH); digitalwrite(lmotor2, LOW); digitalwrite(rmotor1, HIGH); digitalwrite(rmotor2, LOW); delay(a); digitalwrite(lmotor1, LOW); digitalwrite(lmotor2, LOW); digitalwrite(rmotor1, LOW); digitalwrite(rmotor2, LOW); void stand(){ digitalwrite(lmotor1, LOW); digitalwrite(lmotor2, LOW); digitalwrite(rmotor1, LOW); digitalwrite(rmotor2, LOW); void goback(int a){ digitalwrite(lmotor1, LOW); digitalwrite(lmotor2, HIGH); digitalwrite(rmotor1, HIGH); digitalwrite(rmotor2, LOW); delay(a); digitalwrite(lmotor1, LOW); digitalwrite(lmotor2, LOW); digitalwrite(rmotor1, LOW); digitalwrite(rmotor2, LOW); 12

13 void scan2(){ digitalwrite(trig, LOW); delaymicroseconds(2); digitalwrite(trig, HIGH); delaymicroseconds(20); digitalwrite(trig, LOW); distance2 = pulsein(echo2, HIGH)/58.2; delay(10); void scan1(){ digitalwrite(trig, LOW); delaymicroseconds(2); digitalwrite(trig, HIGH); delaymicroseconds(20); digitalwrite(trig, LOW); distance1 = pulsein(echo1, HIGH)/58.2; delay(10); void scan3(){ digitalwrite(trig, LOW); delaymicroseconds(2); digitalwrite(trig, HIGH); delaymicroseconds(20); digitalwrite(trig, LOW); distance3 = pulsein(echo3, HIGH)/58.2; delay(10); void setup() { myservo.attach(9); Serial.begin (57600); pinmode(trig, OUTPUT); pinmode(lmotor1, OUTPUT); pinmode(lmotor2, OUTPUT); pinmode(rmotor1, OUTPUT); pinmode(rmotor2, OUTPUT); pinmode(echo1, INPUT); pinmode(echo2, INPUT); pinmode(echo3, INPUT); TIMSK1 = 0x01;// enabled global and timer overflow interrupt; TCCR1A = 0x00;// noise cancelling didn't work... attachinterrupt(0, interrupt, RISING); pinmode(lled, OUTPUT); pinmode(rled, OUTPUT); 13

14 pinmode(fled, OUTPUT); pinmode(bled, OUTPUT); pinmode(sled, OUTPUT); digitalwrite(lled, LOW); digitalwrite(rled, LOW); digitalwrite(fled, LOW); digitalwrite(bled, LOW); digitalwrite(sled, LOW); void loop() { freq= / divider[prescaler] / count; // T=n/f(fix) f(fix)= /divider f(signal)=1/t Serial.print("Freq: "); Serial.print(freq); if (prescaler > 1) { prescaler--; delay(20); delay(10); n=count if (freq>=586&freq<=596){ changecount++; Serial.print (changecount); if (changecount>=200){ changecount=0; digitalwrite(sled, LOW); if(changecount<=1){ scan1(); scan2(); scan3(); mind=min(min(distance1,distance2),distance3); if(mind>0){ if (mind>=20){ goahead(800); else if (mind<=8){ goback(500); 14

15 else { if (distance1!=distance3){ if (mind==distance1){ turnright(800); if(mind==distance3){ turnleft(800); if (mind==distance2){ goback(800); if (distance1==distance3){ turnright(800); else{ goahead(800); if (changecount>=2){ digitalwrite(sled, HIGH); if (freq>=352&freq<=365){ frontcount++; if(frontcount==2){ digitalwrite(fled, HIGH); goahead(500); digitalwrite(fled, LOW); frontcount=0; if (freq>=393&freq<=408){ leftcount++; if(leftcount==2){ digitalwrite(lled, HIGH); turnleft(400); digitalwrite(lled, LOW); leftcount=0; if (freq>=438&freq<=449){ rightcount++; if(rightcount==2){ digitalwrite(rled, HIGH); turnright(500); digitalwrite(rled, LOW); rightcount=0; 15

16 if (freq>=521&freq<=533){ backcount++; if(backcount==2){ digitalwrite(bled, HIGH); goback(560); backcount=0; digitalwrite(bled, LOW); if (freq>=297&freq<=308){ shootcount++; if(shootcount==2){ digitalwrite(sled, HIGH); myservo.write(177); delay(400); myservo.write(90); delay(400); shootcount=0; digitalwrite(sled, LOW); References