StateMachine.cpp

00001 /*
00002  * StateMachine.cpp
00003  * Copyright (c) 2020, ZHAW
00004  * All rights reserved.
00005  */
00006 
00007 #include <cmath>
00008 #include "StateMachine.h"
00009 
00010 using namespace std;
00011 
00012 const float StateMachine::PERIOD = 0.01f;                   // period of task in [s]
00013 const float StateMachine::DISTANCE_THRESHOLD = 0.2f;        // minimum allowed distance to obstacle in [m]
00014 const float StateMachine::TRANSLATIONAL_VELOCITY = 0.5f;    // translational velocity in [m/s]
00015 const float StateMachine::ROTATIONAL_VELOCITY = 2.0f;       // rotational velocity in [rad/s]
00016 
00017 /**
00018  * Creates and initializes a state machine object.
00019  */
00020 StateMachine::StateMachine(Controller& controller, DigitalOut& enableMotorDriver, DigitalOut& led0, DigitalOut& led1, DigitalOut& led2, DigitalOut& led3, DigitalOut& led4, DigitalOut& led5, DigitalIn& button, IRSensor& irSensor0, IRSensor& irSensor1, IRSensor& irSensor2, IRSensor& irSensor3, IRSensor& irSensor4, IRSensor& irSensor5) : controller(controller), enableMotorDriver(enableMotorDriver), led0(led0), led1(led1), led2(led2), led3(led3), led4(led4), led5(led5), button(button), irSensor0(irSensor0), irSensor1(irSensor1), irSensor2(irSensor2), irSensor3(irSensor3), irSensor4(irSensor4), irSensor5(irSensor5) {
00021     
00022     enableMotorDriver = 0;
00023     state = ROBOT_OFF;
00024     buttonNow = button;
00025     buttonBefore = buttonNow;
00026     
00027     ticker.attach(callback(this, &StateMachine::run), PERIOD);
00028 }
00029 
00030 /**
00031  * Deletes the state machine object and releases all allocated resources.
00032  */
00033 StateMachine::~StateMachine() {
00034     
00035     ticker.detach();
00036 }
00037 
00038 /**
00039  * Gets the actual state of this state machine.
00040  * @return the actual state as an int constant.
00041  */
00042 int StateMachine::getState() {
00043     
00044     return state;
00045 }
00046 
00047 /**
00048  * This method is called periodically by the ticker object and implements the
00049  * logic of the state machine.
00050  */
00051 void StateMachine::run() {
00052     
00053     // set the leds based on distance measurements
00054     
00055     led0 = irSensor0 < DISTANCE_THRESHOLD;
00056     led1 = irSensor1 < DISTANCE_THRESHOLD;
00057     led2 = irSensor2 < DISTANCE_THRESHOLD;
00058     led3 = irSensor3 < DISTANCE_THRESHOLD;
00059     led4 = irSensor4 < DISTANCE_THRESHOLD;
00060     led5 = irSensor5 < DISTANCE_THRESHOLD;
00061     
00062     taskList.clear();
00063     
00064     // implementation of the state machine
00065     
00066     switch (state) {
00067         
00068         case ROBOT_OFF:
00069             while (taskList.size() > 0) {
00070                 delete taskList.front();
00071                 taskList.pop_front();
00072                 }
00073             buttonNow = button;
00074             
00075             if (buttonNow && !buttonBefore) {   // detect button rising edge
00076                 
00077                 enableMotorDriver = 1;
00078                 
00079                 controller.setTranslationalVelocity(TRANSLATIONAL_VELOCITY);
00080                 controller.setRotationalVelocity(0.0f);
00081                 
00082                 taskList.push_back(new TaskMoveTo(controller, 0.0f, 1.0f, 0.0f));
00083                 taskList.push_back(new TaskWait(controller, 2.0f));
00084                 taskList.push_back(new TaskMoveTo(controller, 0.0f, 0.0f, 0.0f));
00085                 
00086                 
00087                 state = MOVE_FORWARD;
00088             }
00089             
00090             buttonBefore = buttonNow;
00091             
00092             break;
00093             
00094         case MOVE_FORWARD:
00095             
00096             buttonNow = button;
00097             
00098             if (taskList.size() > 0) {
00099                 Task* task = taskList.front();
00100                 int result = task->run(PERIOD);
00101                 if (result == Task::DONE) {
00102                 taskList.pop_front();
00103                 delete task;
00104             }
00105             
00106             
00107             } else {
00108                 controller.setTranslationalVelocity(0.0f);
00109                 controller.setRotationalVelocity(0.0f);
00110                 
00111                 state = SLOWING_DOWN;
00112                 }
00113             
00114             if (buttonNow && !buttonBefore) {   // detect button rising edge
00115                 
00116                 controller.setTranslationalVelocity(0.0f);
00117                 controller.setRotationalVelocity(0.0f);
00118                 
00119                 state = SLOWING_DOWN;
00120                 
00121             } else if ((irSensor3 < DISTANCE_THRESHOLD) || (irSensor4 < DISTANCE_THRESHOLD)) {
00122                 
00123                 controller.setTranslationalVelocity(0.0f);
00124                 controller.setRotationalVelocity(ROTATIONAL_VELOCITY);
00125                 
00126                 state = TURN_LEFT;
00127                 
00128             } else if (irSensor2 < DISTANCE_THRESHOLD) {
00129                 
00130                 controller.setTranslationalVelocity(0.0f);
00131                 controller.setRotationalVelocity(-ROTATIONAL_VELOCITY);
00132                 
00133                 state = TURN_RIGHT;
00134                 
00135             } else {
00136                 
00137             }
00138             
00139             buttonBefore = buttonNow;
00140             
00141             break;
00142             
00143         case TURN_LEFT:
00144             
00145             buttonNow = button;
00146             
00147             if (buttonNow && !buttonBefore) {   // detect button rising edge
00148                 
00149                 controller.setRotationalVelocity(0.0f);
00150                 
00151                 state = SLOWING_DOWN;
00152                 
00153             } else if ((irSensor2 > DISTANCE_THRESHOLD) && (irSensor3 > DISTANCE_THRESHOLD) && (irSensor4 > DISTANCE_THRESHOLD)) {
00154                 
00155                 controller.setTranslationalVelocity(TRANSLATIONAL_VELOCITY);
00156                 controller.setRotationalVelocity(0.0f);
00157                 
00158                 state = MOVE_FORWARD;
00159             }
00160             
00161             buttonBefore = buttonNow;
00162             
00163             break;
00164             
00165         case TURN_RIGHT:
00166             
00167             buttonNow = button;
00168             
00169             if (buttonNow && !buttonBefore) {   // detect button rising edge
00170                 
00171                 controller.setRotationalVelocity(0.0f);
00172                 
00173                 state = SLOWING_DOWN;
00174                 
00175             } else if ((irSensor2 > DISTANCE_THRESHOLD) && (irSensor3 > DISTANCE_THRESHOLD) && (irSensor4 > DISTANCE_THRESHOLD)) {
00176                 
00177                 controller.setTranslationalVelocity(TRANSLATIONAL_VELOCITY);
00178                 controller.setRotationalVelocity(0.0f);
00179                 
00180                 state = MOVE_FORWARD;
00181             }
00182             
00183             buttonBefore = buttonNow;
00184             
00185             break;
00186             
00187         case SLOWING_DOWN:
00188         
00189             
00190             
00191             if ((fabs(controller.getActualTranslationalVelocity()) < 0.01f) && (fabs(controller.getActualRotationalVelocity()) < 0.01f)) {
00192                 
00193                 enableMotorDriver = 0;
00194                 
00195                 state = ROBOT_OFF;
00196             }
00197             
00198             break;
00199             
00200         default:
00201             
00202             state = ROBOT_OFF;
00203     }
00204 }
00205