Diff: Sonar.cpp

Revision:

33:814bcd7d3cfe

Child:

34:c208497dd079

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Sonar.cpp	Fri Jun 09 00:28:32 2017 +0000
@@ -0,0 +1,104 @@
+#include "Sonar.hpp"
+
+Sonar::Sonar(float anlgeFromCenter, float distanceXRobot, float distanceYRobot ){
+	this->anlgeFromCenter=anlgeFromCenter;
+	this->distanceXRobot=-distanceYRobot;
+	this->distanceYRobot=distanceXRobot;
+	this->maxRange=50;//cm
+	this->minRange=10;//Rmin cm
+	this->incertitudeRange=10;//cm
+	this->angleRange=3.14159/3;//Omega rad
+}
+
+//ODOMETRIA MUST HAVE BEEN CALLED
+//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 x, float y, float robotCoordinateXWorld, float robotCoordinateYWorld){
+	float xSonar=robotCoordinateXWorld+this->distanceX;
+	float ySonar=robotCoordinateYWorld+this->distanceY;
+    float distancePointToSonar=sqrt(pow(x-xSonar,2)+pow(y-ySonar,2));
+    if( distancePointToSonar < this->maxRange){
+        float anglePointToSonar=this->compute_angle_between_vectors(x,y,xSonar,ySonar);//angle beetween the point and the sonar beam
+        float alphaBeforeAdjustment=anglePointToSonar-theta-angleFromSonarPosition;
+        anglePointToSonar=rad_angle_check(alphaBeforeAdjustment);//TODO I feel you don't need to do that but I m not sure
+        
+        if(alphaBeforeAdjustment>pi)
+            alphaBeforeAdjustment=alphaBeforeAdjustment-2*pi;
+        if(alphaBeforeAdjustment<-pi)
+            alphaBeforeAdjustment=alphaBeforeAdjustment+2*pi;
+            
+        //float anglePointToSonar2=atan2(y-ys,x-xs)-theta;
+        
+        //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(anglePointToSonar <= this->angleRange/2 || anglePointToSonar >= this->rad_angle_check(-this->angleRange/2)){
+            if( distancePointToSonar < (distanceObstacleDetected - this->incertitudeRange)){
+            //point before obstacle, probably empty
+            /*****************************************************************************/
+                float Ea=1.f-pow((2*alphaBeforeAdjustment)/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,alphaBeforeAdjustment=%f",(1.f-Er*Ea)/2.f,Er,Ea,alphaBeforeAdjustment);
+                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 + 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,alphaBeforeAdjustment=%f",(1+Or*Oa)/2,Or,Oa,alphaBeforeAdjustment);
+                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){
+    //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;
+}
+