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     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     
00064     
00065     // implementation of the state machine
00066     
00067     switch (state) {
00068         
00069         case ROBOT_OFF:
00070         
00071             while(taskList.size() > 0){
00072                 delete taskList.front();
00073                 taskList.pop_front();
00074                 }
00075             
00076             buttonNow = button;
00077             
00078             if (buttonNow && !buttonBefore) {   // detect button rising edge
00079                 
00080                 enableMotorDriver = 1;
00081                 
00082 //                controller.setTranslationalVelocity(TRANSLATIONAL_VELOCITY);
00083 //                controller.setRotationalVelocity(0.0f);
00084                 taskList.push_back(new TaskMoveTo(controller, 0.0f, 1.0f, 0.0f));
00085                 //taskList.push_back(new TaskWait(controller,2.0f));
00086                 taskList.push_back(new TaskMoveTo(controller, 0.1f, 0.9f, 0.0f));
00087                 taskList.push_back(new TaskMoveTo(controller, 0.0f, 0.0f, 0.0f));
00088                 state = MOVE_FORWARD;
00089             }
00090             
00091             buttonBefore = buttonNow;
00092             
00093             break;
00094             
00095         case MOVE_FORWARD:
00096             
00097             buttonNow = button;
00098 
00099             if (buttonNow && !buttonBefore) {   // detect button rising edge
00100 
00101                 controller.setTranslationalVelocity(0.0f);
00102                 controller.setRotationalVelocity(0.0f);
00103                     
00104                 state = SLOWING_DOWN;
00105                 
00106             } else if ((irSensor3 < DISTANCE_THRESHOLD) || (irSensor4 < DISTANCE_THRESHOLD)) {
00107                 
00108                 controller.setTranslationalVelocity(0.0f);
00109                 controller.setRotationalVelocity(ROTATIONAL_VELOCITY);
00110                 
00111                 state = TURN_LEFT;
00112                 
00113             } else if (irSensor2 < DISTANCE_THRESHOLD) {
00114                 
00115                 controller.setTranslationalVelocity(0.0f);
00116                 controller.setRotationalVelocity(-ROTATIONAL_VELOCITY);
00117                 
00118                 state = TURN_RIGHT;
00119                 
00120             } else {
00121 
00122                 if(taskList.size() > 0){
00123 
00124                     Task* task = taskList.front();
00125                     int result = task->run(PERIOD);
00126                     
00127                     if(result == Task::DONE){
00128                         taskList.pop_front();
00129                         delete task;
00130                         }
00131                     }
00132             }
00133             
00134             buttonBefore = buttonNow;
00135             
00136             break;
00137             
00138         case TURN_LEFT:
00139             
00140             buttonNow = button;
00141             
00142             if (buttonNow && !buttonBefore) {   // detect button rising edge
00143                 
00144                 controller.setRotationalVelocity(0.0f);
00145                 
00146                 state = SLOWING_DOWN;
00147                 
00148             } else if ((irSensor2 > DISTANCE_THRESHOLD) && (irSensor3 > DISTANCE_THRESHOLD) && (irSensor4 > DISTANCE_THRESHOLD)) {
00149                 
00150                 controller.setTranslationalVelocity(TRANSLATIONAL_VELOCITY);
00151                 controller.setRotationalVelocity(0.0f);
00152                 
00153                 state = MOVE_FORWARD;
00154             }
00155             
00156             buttonBefore = buttonNow;
00157             
00158             break;
00159             
00160         case TURN_RIGHT:
00161             
00162             buttonNow = button;
00163             
00164             if (buttonNow && !buttonBefore) {   // detect button rising edge
00165                 
00166                 controller.setRotationalVelocity(0.0f);
00167                 
00168                 state = SLOWING_DOWN;
00169                 
00170             } else if ((irSensor2 > DISTANCE_THRESHOLD) && (irSensor3 > DISTANCE_THRESHOLD) && (irSensor4 > DISTANCE_THRESHOLD)) {
00171                 
00172                 controller.setTranslationalVelocity(TRANSLATIONAL_VELOCITY);
00173                 controller.setRotationalVelocity(0.0f);
00174                 
00175                 state = MOVE_FORWARD;
00176             }
00177             
00178             buttonBefore = buttonNow;
00179             
00180             break;
00181             
00182         case SLOWING_DOWN:
00183             
00184             if ((fabs(controller.getActualTranslationalVelocity()) < 0.01f) && (fabs(controller.getActualRotationalVelocity()) < 0.01f)) {
00185                 
00186                 enableMotorDriver = 0;
00187                 
00188                 state = ROBOT_OFF;
00189             }
00190             
00191             break;
00192             
00193         default:
00194             
00195             state = ROBOT_OFF;
00196     }
00197 }
00198