Compensation for Positional Errors in MMW Radar SLAM Caused by Observation Deviations and Coordinate System Transformation

Nowadays, because of Millimeter-wave (MMW) radar can stably perform Simultaneous Localization and Mapping(SLAM) in bad weather, so it plays an important role in application scenarios such as autonomous driving and disaster rescue, etc. Existing research considered to observation of MMWradars are conformed to 0-means Gaussian Distribution, so the localization based on MMW radar is conformed to the distribution, too. However, the change of observation’s distribution because of coordinate transform was ignored. So, the conclusion is drawn out that the estimated position will cumulate error with fixed direction when the robot is located by MMW radar after the analysis of this paper. This paper utilizes the correlative scan matching (CSM) method in radar SLAM to analyze the error form with different coordinate transforms. The error of one landmark, the effect of localization due to a set of landmarks, and the trend of accumulation of errors are analytic, respectively. A simulation method based on Monte Carlo sampling is used to prove the conclusion in theory. In order to solve this problem, a CSM-based cumulative error expectation compensation (CEEC-CSM) method is proposed. Four scenes experiments were used to prove that the position error of the CEEC-CSM method is reduced by 49%.