StateMachine.cpp

00001 /*
00002  * StateMachine.cpp
00003  * Copyright (c) 2018, 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 = 0.3f;    // translational velocity in [m/s]
00015 const float StateMachine::ROTATIONAL_VELOCITY = 1.0f;       // 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     taskList.clear();
00027     
00028     ticker.attach(callback(this, &StateMachine::run), PERIOD);
00029 }
00030 
00031 /**
00032  * Deletes the state machine object and releases all allocated resources.
00033  */
00034 StateMachine::~StateMachine() {
00035     
00036     ticker.detach();
00037 }
00038 
00039 /**
00040  * Gets the actual state of this state machine.
00041  * @return the actual state as an int constant.
00042  */
00043 int StateMachine::getState() {
00044     
00045     return state;
00046 }
00047 
00048 /**
00049  * This method is called periodically by the ticker object and implements the
00050  * logic of the state machine.
00051  */
00052 void StateMachine::run() {
00053     
00054     // set the leds based on distance measurements
00055     /*
00056     led0 = irSensor0 < DISTANCE_THRESHOLD;
00057     led1 = irSensor1 < DISTANCE_THRESHOLD;
00058     led2 = irSensor2 < DISTANCE_THRESHOLD;
00059     led3 = irSensor3 < DISTANCE_THRESHOLD;
00060     led4 = irSensor4 < DISTANCE_THRESHOLD;
00061     led5 = irSensor5 < DISTANCE_THRESHOLD;
00062     */
00063     // implementation of the state machine
00064     
00065     switch (state) {
00066         
00067         case ROBOT_OFF:
00068             
00069             buttonNow = button;
00070             
00071             if (buttonNow && !buttonBefore) {   // detect button rising edge
00072                 
00073                 enableMotorDriver = 1;
00074                 
00075                 taskList.push_back(new TaskWait(controller, 0.5f));
00076                 taskList.push_back(new TaskMove(controller, 0.1f, 0.0f));
00077                 
00078                 state = PROCESSING_TASKS;
00079             }
00080             
00081             buttonBefore = buttonNow;
00082             
00083             break;
00084             
00085         case PROCESSING_TASKS:
00086             
00087             buttonNow = button;
00088             
00089             if (buttonNow && !buttonBefore) {   // detect button rising edge
00090                 
00091                 controller.setTranslationalVelocity(0.0f);
00092                 controller.setRotationalVelocity(0.0f);
00093                 
00094                 state = SLOWING_DOWN;
00095                 
00096             } else if ((irSensor0 < DISTANCE_THRESHOLD) || (irSensor1 < DISTANCE_THRESHOLD)) {
00097                 
00098                 controller.setTranslationalVelocity(0.0f);
00099                 controller.setRotationalVelocity(ROTATIONAL_VELOCITY);
00100                 
00101                 state = TURN_LEFT;
00102                 
00103             } else if (irSensor5 < DISTANCE_THRESHOLD) {
00104                 
00105                 controller.setTranslationalVelocity(0.0f);
00106                 controller.setRotationalVelocity(-ROTATIONAL_VELOCITY);
00107                 
00108                 state = TURN_RIGHT;
00109                 
00110             } else if (taskList.size() > 0) {
00111                 
00112                 Task* task = taskList.front();
00113                 int result = task->run(PERIOD);
00114                 if (result == Task::DONE) {
00115                     taskList.pop_front();
00116                     delete task;
00117                 }
00118                 
00119             } else {
00120                 
00121                 controller.setTranslationalVelocity(0.0f);
00122                 controller.setRotationalVelocity(0.0f);
00123                 
00124                 state = SLOWING_DOWN;
00125             }
00126             
00127             buttonBefore = buttonNow;
00128             
00129             break;
00130             
00131         case TURN_LEFT:
00132             
00133             buttonNow = button;
00134             
00135             if (buttonNow && !buttonBefore) {   // detect button rising edge
00136                 
00137                 controller.setTranslationalVelocity(0.0f);
00138                 controller.setRotationalVelocity(0.0f);
00139                 
00140                 state = SLOWING_DOWN;
00141                 
00142             } else if ((irSensor0 > DISTANCE_THRESHOLD) && (irSensor1 > DISTANCE_THRESHOLD) && (irSensor5 > DISTANCE_THRESHOLD)) {
00143                 
00144                 state = PROCESSING_TASKS;
00145             }
00146             
00147             buttonBefore = buttonNow;
00148             
00149             break;
00150             
00151         case TURN_RIGHT:
00152             
00153             buttonNow = button;
00154             
00155             if (buttonNow && !buttonBefore) {   // detect button rising edge
00156                 
00157                 controller.setTranslationalVelocity(0.0f);
00158                 controller.setRotationalVelocity(0.0f);
00159                 
00160                 state = SLOWING_DOWN;
00161                 
00162             } else if ((irSensor0 > DISTANCE_THRESHOLD) && (irSensor1 > DISTANCE_THRESHOLD) && (irSensor5 > DISTANCE_THRESHOLD)) {
00163                 
00164                 state = PROCESSING_TASKS;
00165             }
00166             
00167             buttonBefore = buttonNow;
00168             
00169             break;
00170             
00171         case SLOWING_DOWN:
00172             
00173             if ((fabs(controller.getActualTranslationalVelocity()) < 0.01f) && (fabs(controller.getActualRotationalVelocity()) < 0.01f)) {
00174                 
00175                 enableMotorDriver = 0;
00176                 
00177                 while (taskList.size() > 0) {
00178                     delete taskList.front();
00179                     taskList.pop_front();
00180                 }
00181                 
00182                 state = ROBOT_OFF;
00183             }
00184             
00185             break;
00186             
00187         default:
00188             
00189             state = ROBOT_OFF;
00190     }
00191 }
00192