added assert

src/sensor/sensor_odom_2d.cpp

@@ -36,6 +36,7 @@ double SensorOdom2d::getRotVarToRotNoiseFactor() const
 
 Eigen::Matrix2d SensorOdom2d::computeCovFromMotion (const VectorXd& _data) const
 {
+    assert(_data.size() == 2);
     double d = fabs(_data(0));
     double r = fabs(_data(1));