private boolean isWallDetected() {

		if ((sensorThread.getSonarDistance1() < MAX_DISTANCE && sensorThread.getSonarDistance2() < CONTROL_DISTANCE
				|| sensorThread.getSonarDistance2() < MAX_DISTANCE && sensorThread.getSonarDistance1() < CONTROL_DISTANCE) 
				&& Math.abs(sensorThread.getSonarDistance1()- sensorThread.getSonarDistance2())> ERROR) {
			return true;
		}
		
		else {
			return false;
		}
	}