Navigate to a given point using the OGM and virtual forces
Dependencies: ISR_Mini-explorer mbed
Fork of VirtualForces by
main.cpp
- Committer:
- geotsam
- Date:
- 2017-04-19
- Revision:
- 23:901fc468b8a7
- Parent:
- 22:ebb37a249b5f
- Child:
- 24:8f4b820d8de8
File content as of revision 23:901fc468b8a7:
#include "mbed.h" #include "robot.h" // Initializes the robot. This include should be used in all main.cpp! #include "math.h" using namespace std; //fill initialLogValues with the values we already know (here the bordurs) void fill_initial_log_values(); //generate a position randomly and makes the robot go there while updating the map void randomize_and_map(); //go the the given position while updating the map void go_to_point_with_angle(float target_x, float target_y, float target_angle); //Updates sonar values void update_sonar_values(); //function that check if a cell A(x,y) is in the range of the front sonar S(xs,ys) (with an angle depending on the sonar used, front 0, left pi/3, right -pi/3) returns the probability it's occupied/empty [0;1] float compute_probability_t(float x, float y,float xs,float ys, float angleFromSonarPosition, float distanceObstacleDetected); //print the map void print_final_map(); //compute the angles and distance used for the velocities void compute_angles_and_distance(float target_x, float target_y, float target_angle); //compute the linear and 2 angular velocities void compute_linear_angular_velocities(); //MATHS heavy functions float dist(float robot_x, float robot_y, float target_x, float target_y); //returns the probability [0,1] that the cell is occupied from the log value lt float log_to_proba(float lt); //returns the log value that the cell is occupied from the probability value [0,1] float proba_to_log(float p); //returns the new log value float compute_log_estimation_lt(float previousLogValue,float currentProbability,float originalLogvalue ); //makes the angle inAngle between 0 and 2pi float rad_angle_check(float inAngle); //returns the angle between the vectors (x,y) and (xs,ys) float compute_angle_between_vectors(float x, float y,float xs,float ys); const float pi=3.14159; //spec of the sonar //TODO MEASURE THE DISTANCE on X and Y of the robot frame, between each sonar and the center of the robot and add it to calculus in updateSonarValues const float RANGE_SONAR=50;//RADIUS_WHEELS const float RANGE_SONAR_MIN=10;//Rmin const float INCERTITUDE_SONAR=10; const float ANGLE_SONAR=pi/3;//Omega //those distance and angle are approximation in need of measurements const float ANGLE_FRONT_TO_LEFT=pi/3; const float DISTANCE_SONAR_LEFT_X=5; const float DISTANCE_SONAR_LEFT_Y=5; float leftMm; const float ANGLE_FRONT_TO_RIGHT=-pi/3; const float DISTANCE_SONAR_RIGHT_X=-5; const float DISTANCE_SONAR_RIGHT_Y=5; float rightMm; const float ANGLE_FRONT_TO_FRONT=0; const float DISTANCE_SONAR_FRONT_X=0; const float DISTANCE_SONAR_FRONT_Y=5; float frontMm; //TODO adjust the size of the map for computation time (25*25?) const int SIZE_MAP=25; //position and orientation of the robot when put on the map (ODOMETRY doesn't know those) const float DEFAULT_X=0; const float DEFAULT_Y=0; const float DEFAULT_THETA=pi/2; //used to create the map 250 represent the 250cm of the table where the robot is tested float sizeCell=250/(float)SIZE_MAP; float map[SIZE_MAP][SIZE_MAP];//contains the log values for each cell float initialLogValues[SIZE_MAP][SIZE_MAP]; //Diameter of a wheel and distance between the 2 const float RADIUS_WHEELS=3.25; const float DISTANCE_WHEELS=7.2; float alpha; //angle error float rho; //distance from target float beta; float kRho=12, ka=30, kb=-13; //Kappa values float linear, angular, angular_left, angular_right; float dt=0.5; float temp; float d2; Timer t; int speed=999; // Max speed at beggining of movement int main(){ i2c1.frequency(100000); initRobot(); //Initializing the robot pc.baud(9600); // baud for the pc communication measure_always_on();//TODO check if needed fill_initial_log_values(); for (int i = 0; i<25; i++) { randomize_and_map(); } //Stop at the end leftMotor(1,0); rightMotor(1,0); //pc.printf("\n\r %f -- arrived!", rho); print_final_map(); } //fill initialLogValues with the values we already know (here the bordurs) void fill_initial_log_values(){ //Fill map, we know the border are occupied for (int i = 0; i<SIZE_MAP; i++) { for (int j = 0; j<SIZE_MAP; j++) { if(j==0 || j==SIZE_MAP-1 || i==0 || i==SIZE_MAP-1) initialLogValues[i][j] = proba_to_log(1); else initialLogValues[i][j] = proba_to_log(0.5); } } } //generate a position randomly and makes the robot go there while updating the map void randomize_and_map() { float target_x = (rand()%2500)/10;//for decimal precision float target_y = (rand()%2500)/10; float target_angle = ((float)(rand()%31416)-15708)/10000.0; /* pc.printf("\n\r targ_X=%f", target_x); pc.printf("\n\r targ_Y=%f", target_y); pc.printf("\n\r targ_Angle=%f", target_angle); */ go_to_point_with_angle(target_x, target_y, target_angle); } //go the the given position while updating the map //TODO clean this procedure it's ugly as hell and too long void go_to_point_with_angle(float target_x, float target_y, float target_angle) { bool tooClose=false; //binary variable to know if an obstacle is <10cm away do { pc.printf("\n\n\r entered while"); //Timer stuff dt = t.read(); t.reset(); t.start(); //Updating X,Y and theta with the odometry values Odometria(); //Updare the values from the sonar update_sonar_values(); //Check if one of the sonars finds an obstacle that is too close if (leftMm < 100 || frontMm < 100 || rightMm < 100) { tooClose = true; break; } compute_angles_and_distance(target_x, target_y, target_angle); //Compute the angles and the distance from target compute_linear_angular_velocities(); //Using the angles and distance, compute the velocities needed (linear & angular) //Printing values for debugging purposes pc.printf("\n\r X=%f", X); pc.printf("\n\r Y=%f", Y); pc.printf("\n\r leftMm=%f", leftMm); pc.printf("\n\r frontMm=%f", frontMm); pc.printf("\n\r rightMm=%f", rightMm); //Updating motor velocities leftMotor(1,angular_left); rightMotor(1,angular_right); wait(0.2); //Timer stuff t.stop(); } while(d2>1 && tooClose==false); } //Updates sonar values void update_sonar_values(){ float leftMm = get_distance_left_sensor(); float frontMm = get_distance_front_sensor(); float rightMm = get_distance_right_sensor(); float currProba; for(int i=0;i<SIZE_MAP;i++){ for(int j=0;j<SIZE_MAP;j++){ //check if the point A(x,y) in the world frame is within the range of the sonar (which has the coordinates xs, ys in the world frame) //compute for front sonar currProba=compute_probability_t(sizeCell/2+i*sizeCell,sizeCell/2+j*sizeCell,SIZE_MAP*sizeCell-X+DEFAULT_X+DISTANCE_SONAR_FRONT_X,Y+DEFAULT_Y+DISTANCE_SONAR_FRONT_Y,ANGLE_FRONT_TO_FRONT,frontMm/10); map[i][j]=map[i][j]+proba_to_log(currProba)+initialLogValues[i][j];//map is filled as map[0][0] get the data for the point closest to the origin //compute for right sonar currProba=compute_probability_t(sizeCell/2+i*sizeCell,sizeCell/2+j*sizeCell,SIZE_MAP*sizeCell-X+DEFAULT_X+DISTANCE_SONAR_RIGHT_X,Y+DEFAULT_Y+DISTANCE_SONAR_RIGHT_Y,ANGLE_FRONT_TO_RIGHT,rightMm/10); map[i][j]=map[i][j]+proba_to_log(currProba)+initialLogValues[i][j]; //compute for left sonar currProba=compute_probability_t(sizeCell/2+i*sizeCell,sizeCell/2+j*sizeCell,SIZE_MAP*sizeCell-X+DEFAULT_X+DISTANCE_SONAR_LEFT_X,Y+DEFAULT_Y+DISTANCE_SONAR_LEFT_Y,ANGLE_FRONT_TO_LEFT,leftMm/10); map[i][j]=map[i][j]+proba_to_log(currProba)+initialLogValues[i][j]; } } } //function that check if a cell A(x,y) is in the range of the front sonar S(xs,ys) (with an angle depending on the sonar used, front 0, left pi/3, right -pi/3) returns the probability it's occupied/empty [0;1] float compute_probability_t(float x, float y,float xs,float ys, float angleFromSonarPosition, float distanceObstacleDetected){ float alpha=compute_angle_between_vectors(x,y,xs,ys);//angle beetween the point and the sonar beam float alphaBeforeAdjustment=alpha-theta-DEFAULT_THETA-angleFromSonarPosition; alpha=rad_angle_check(alphaBeforeAdjustment);//TODO I feel you don't need to do that but I m not sure float distancePointToSonar=sqrt(pow(x-xs,2)+pow(y-ys,2)); //check if the distance between the cell and the robot is within the circle of range RADIUS_WHEELS //check if absolute difference between the angles is no more than Omega/2 if( distancePointToSonar < (RANGE_SONAR)&& (alpha <= ANGLE_SONAR/2 || alpha >= rad_angle_check(-ANGLE_SONAR/2))){ if( distancePointToSonar < (distanceObstacleDetected - INCERTITUDE_SONAR)){ //point before obstacle, probably empty /*****************************************************************************/ float Ea=1.f-pow((2*alphaBeforeAdjustment)/ANGLE_SONAR,2); float Er; if(distancePointToSonar < RANGE_SONAR_MIN){ //point before minimum sonar range Er=0.f; }else{ //point after minimum sonar range Er=1.f-pow((distancePointToSonar-RANGE_SONAR_MIN)/(distanceObstacleDetected-INCERTITUDE_SONAR-RANGE_SONAR_MIN),2); } /*****************************************************************************/ return (1.f-Er*Ea)/2.f; }else{ //probably occupied /*****************************************************************************/ float Oa=1.f-pow((2*alphaBeforeAdjustment)/ANGLE_SONAR,2); float Or; if( distancePointToSonar <= (distanceObstacleDetected + INCERTITUDE_SONAR)){ //point between distanceObstacleDetected +- INCERTITUDE_SONAR Or=1-pow((distancePointToSonar-distanceObstacleDetected)/(INCERTITUDE_SONAR),2); }else{ //point after in range of the sonar but after the zone detected Or=0; } /*****************************************************************************/ return (1+Or*Oa)/2; } }else{ //not in range of the sonar return 0.5; } } void print_final_map() { float currProba; for (int x = 0; x<SIZE_MAP; x++) { for (int y = 0; y<SIZE_MAP; y++) { currProba=log_to_proba(map[SIZE_MAP-1-x][y]); if ( currProba < 0.5) {//by default [0][0] would be top left, we want it bottom left pc.printf("0"); } else { if(currProba==0.5) pc.printf("."); else pc.printf("+"); } } } } //MATHS heavy functions /**********************************************************************/ //Distance computation function float dist(float robot_x, float robot_y, float target_x, float target_y){ return sqrt(pow(target_y-robot_y,2) + pow(target_x-robot_x,2)); } //returns the probability [0,1] that the cell is occupied from the log value lt float log_to_proba(float lt){ return 1-1/(1+exp(lt)); } //returns the log value that the cell is occupied from the probability value [0,1] float proba_to_log(float p){ return log(p/(1-p)); } //returns the new log value float compute_log_estimation_lt(float previousLogValue,float currentProbability,float originalLogvalue ){ return previousLogValue+proba_to_log(currentProbability)-originalLogvalue; } //makes the angle inAngle between 0 and 2pi float rad_angle_check(float inAngle){ //cout<<"before :"<<inAngle; if(inAngle > 0){ while(inAngle > (2*pi)) inAngle-=2*pi; }else{ while(inAngle < 0) inAngle+=2*pi; } //cout<<" after :"<<inAngle<<endl; return inAngle; } //returns the angle between the vectors (x,y) and (xs,ys) float compute_angle_between_vectors(float x, float y,float xs,float ys){ //alpha angle between ->x and ->SA //vector S to A ->SA float vSAx=x-xs; float vSAy=y-ys; //norme SA float normeSA=sqrt(pow(vSAx,2)+pow(vSAy,2)); //vector ->x (1,0) float cosAlpha=1*vSAy/*+0*vSAx*//normeSA;; //vector ->y (0,1) float sinAlpha=/*0*vSAy+*/1*vSAx/normeSA;//+0*vSAx; if (sinAlpha < 0) return -acos(cosAlpha); else return acos(cosAlpha); } void compute_angles_and_distance(float target_x, float target_y, float target_angle){ alpha = atan2((target_y-Y),(target_x-X))-theta; alpha = atan(sin(alpha)/cos(alpha)); rho = dist(X, Y, target_x, target_y); d2 = rho; beta = -alpha-theta+target_angle; //Computing angle error and distance towards the target value rho += dt*(-kRho*cos(alpha)*rho); temp = alpha; alpha += dt*(kRho*sin(alpha)-ka*alpha-kb*beta); beta += dt*(-kRho*sin(temp)); pc.printf("\n\r d2=%f", d2); pc.printf("\n\r dt=%f", dt); } void compute_linear_angular_velocities(){ //Computing linear and angular velocities if(alpha>=-1.5708 && alpha<=1.5708){ linear=kRho*rho; angular=ka*alpha+kb*beta; } else{ linear=-kRho*rho; angular=-ka*alpha-kb*beta; } angular_left=(linear-0.5*DISTANCE_WHEELS*angular)/RADIUS_WHEELS; angular_right=(linear+0.5*DISTANCE_WHEELS*angular)/RADIUS_WHEELS; //Slowing down at the end for more precision if (d2<25) { speed = d2*30; } //Normalize speed for motors if(angular_left>angular_right) { angular_right=speed*angular_right/angular_left; angular_left=speed; } else { angular_left=speed*angular_left/angular_right; angular_right=speed; } }