 Qualitative and quantitative results show that our method achieves state-of-the-art performance in accuracy and is about twice as fast as the ORB-SLAM2 
<clarity>  Qualitative and quantitative results show that our method achieves state-of-the-art performance in accuracy and is about twice as fast as the ORB-SLAM2 
 Qualitative and quantitative results show that our method achieves state-of-the-art accuracy and is about twice as fast as the ORB-SLAM2 