Diff: Sonar.cpp

Revision:

0:9f7ee7ed13e4

Child:

2:11cd5173aa36

diff -r 000000000000 -r 9f7ee7ed13e4 Sonar.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Sonar.cpp	Mon Jun 26 12:05:20 2017 +0000
@@ -0,0 +1,129 @@
+#include "Sonar.hpp"
+
+#define PI 3.14159
+
+Sonar::Sonar(float angleFromCenter, float distanceXFromRobotCenter, float distanceYFromRobotCenter ){
+	this->angleFromCenter=angleFromCenter;
+	this->distanceX=distanceXFromRobotCenter;
+	this->distanceY=distanceYFromRobotCenter;
+	this->maxRange=50;//cm
+	this->minRange=10;//Rmin cm
+	this->incertitudeRange=10;//cm
+	this->angleRange=3.14159/3;//Omega rad
+}
+
+//return distance sonar to cell if in range, -1 if not
+float Sonar::isInRange(float xCell, float yCell, float xRobotWorld, float yRobotWorld, float thetaWorld){
+	float xSonar=xRobotWorld+this->distanceX;
+	float ySonar=yRobotWorld+this->distanceY;	
+	float distanceCellToSonar=sqrt(pow(xCell-xSonar,2)+pow(yCell-ySonar,2));
+	
+	//check if the distance between the cell and the robot is within the circle of range RADIUS_WHEELS
+    if( distanceCellToSonar < this->maxRange){
+        //float anglePointToSonar=this->compute_angle_between_vectors(xCell,yCell,xSonar,ySonar);//angle beetween the point and the sonar beam
+        float angleCellToSonar=atan2(yCell-yRobotWorld,xCell-xRobotWorld);//like world system
+        
+       	       	float angleOriginToMidleOfBeam=thetaWorld+this->angleFromCenter;//
+
+        float angleDifference=angleCellToSonar-angleOriginToMidleOfBeam;
+        if(angleDifference > PI)
+            angleDifference=angleDifference-2*PI;
+        if(angleDifference < -PI)
+            angleDifference=angleDifference+2*PI;
+        //check if absolute difference between the angles is no more than Omega/2
+        if(angleDifference > 0 && angleDifference <= this->angleRange/2 ||angleDifference < 0 && angleDifference >= -this->angleRange/2 ){
+        	return distanceCellToSonar;
+        }
+    }
+    return -1;
+}
+
+//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 Sonar::compute_probability_t(float distanceObstacleDetected, float xCell, float yCell, float xRobotWorld, float yRobotWorld, float thetaWorld){
+	float xSonar=xRobotWorld+this->distanceX;
+	float ySonar=yRobotWorld+this->distanceY;
+    float distancePointToSonar=sqrt(pow(xCell-xSonar,2)+pow(yCell-ySonar,2));
+    //check if the distance between the cell and the robot is within the circle of range RADIUS_WHEELS
+    if( distancePointToSonar < this->maxRange){
+        //float anglePointToSonar=this->compute_angle_between_vectors(xCell,yCell,xSonar,ySonar);//angle beetween the point and the sonar beam
+        float anglePointToSonar=atan2(yCell-yRobotWorld,xCell-xRobotWorld);//like world system
+        
+       	       	float angleOriginToMidleOfBeam=thetaWorld+this->angleFromCenter;//
+
+        float angleDifference=anglePointToSonar-angleOriginToMidleOfBeam;
+        if(angleDifference > PI)
+            angleDifference=angleDifference-2*PI;
+        if(angleDifference < -PI)
+            angleDifference=angleDifference+2*PI;
+        //check if absolute difference between the angles is no more than Omega/2
+        if(angleDifference > 0 && angleDifference <= this->angleRange/2 ||angleDifference < 0 && angleDifference >= -this->angleRange/2 ){
+
+            if( distancePointToSonar < (distanceObstacleDetected - this->incertitudeRange)){
+            //point before obstacle, probably empty
+            /*****************************************************************************/
+                float Ea=1.f-pow((2*angleDifference)/this->angleRange,2);
+                float Er;
+                if(distancePointToSonar < this->minRange){
+                    //point before minimum sonar range
+                    Er=0.f;
+                }else{
+                    //point after minimum sonar range
+                    Er=1.f-pow((distancePointToSonar-this->minRange)/(distanceObstacleDetected-this->incertitudeRange-this->minRange),2);
+                }
+             /*****************************************************************************/
+                //if((1.f-Er*Ea)/2.f >1 || (1.f-Er*Ea)/2.f < 0)
+                //    pc.printf("\n\r return value=%f,Er=%f,Ea=%f,angleDifference=%f",(1.f-Er*Ea)/2.f,Er,Ea,angleDifference);
+                return (1.f-Er*Ea)/2.f;
+            }else{
+                //probably occuPIed
+            /*****************************************************************************/
+                float Oa=1.f-pow((2*angleDifference)/this->angleRange,2);
+                float Or;
+                if( distancePointToSonar <= (distanceObstacleDetected + this->incertitudeRange)){
+                    //point between distanceObstacleDetected +- INCERTITUDE_SONAR
+                    Or=1-pow((distancePointToSonar-distanceObstacleDetected)/(this->incertitudeRange),2);
+                }else{
+                    //point after in range of the sonar but after the zone detected
+                    Or=0;
+                }
+            /*****************************************************************************/
+                //if((1+Or*Oa)/2 >1 || (1+Or*Oa)/2 < 0)
+                //    pc.printf("\n\r return value=%f,Er=%f,Ea=%f,angleDifference=%f",(1+Or*Oa)/2,Or,Oa,angleDifference);
+                return (1+Or*Oa)/2;
+            }
+        }   
+    }
+    //not checked by the sonar
+    return 0.5;
+}
+
+//returns the angle between the vectors (x,y) and (xs,ys)
+float Sonar::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);
+}
+
+//makes the angle inAngle between 0 and 2PI
+float Sonar::rad_angle_check(float inAngle){
+    if(inAngle > 0){
+        while(inAngle > (2*PI))
+            inAngle-=2*PI;
+    }else{
+        while(inAngle < 0)
+            inAngle+=2*PI;
+    }
+    return inAngle;
+}
+