Eric, I am working together with zhiping and here are some follow-ups for the testing. We attached a gyroscope to the robot and also wrote a ros node to interpret the gyro's output, i.e., the yaw angle, into Imu message; then we tested the csm again. The observation shows the csm output is obviously more stable than before. When somebody move into the laser's view field and disappear, the pose2D.x, pose2D.y curve fluctuates in much smaller scale. Yet unfortunately, the above x, y values still keep drifting no matter human interference exists or not. A youtube link or bag file will be posed later. So we agree this limitation, i.e., to interpret a person walking as movement of the robot, is inherently from the csm algorithm itself. An alternative algorithm being free of this would really be preferred. If I am not wrong, some scan matching algorithms, such as HAYAI, claims robust in dynamic environments. Do you guys have experience on that? best regards xiaojun -- View this message in context: http://ros-users.122217.n3.nabble.com/Problem-with-canonical-scan-matcher-tp2197613p2210070.html Sent from the ROS-Users mailing list archive at Nabble.com.