# A Two-Step Filtering Approach for Indoor LiDAR Point Clouds: Efficient Removal of Jump Points and Misdetected Points

## TL;DR

This paper introduces a two-step filtering method to improve indoor LiDAR data quality for robots by removing jump and misdetected points.

## Contribution

A novel two-step filtering approach combining radial-tangential clustering and grid penetration modeling for LiDAR point cloud processing.

## Key findings

- The first step effectively filters jump points using radial distance and tangential span clustering.
- The second step reduces misdetected points on smooth surfaces via a grid penetration model.
- Experiments show improved navigational accuracy and stability in indoor SLAM for mobile robots.

## Abstract

In the simultaneous localization and mapping (SLAM) process of indoor mobile robots, accurate and stable point cloud data are crucial for localization and environment perception. However, in practical applications indoor mobile robots may encounter glass, smooth floors, edge objects, etc. Point cloud data are often misdetected in such environments, especially at the intersection of flat surfaces and edges of obstacles, which are prone to generating jump points. Smooth planes may also lead to the emergence of misdetected points due to reflective properties or sensor errors. To solve these problems, a two-step filtering method is proposed in this paper. In the first step, a clustering filtering algorithm based on radial distance and tangential span is used for effective filtering against jump points. The algorithm ensures accurate data by analyzing the spatial relationship between each point in the point cloud and the neighboring points, which allows it to identify and filter out the jump points. In the second step, a filtering algorithm based on the grid penetration model is used to further filter out misdetected points on the smooth plane. The model eliminates unrealistic point cloud data and improves the overall quality of the point cloud by simulating the characteristics of the beam penetrating the object. Experimental results in indoor environments show that this two-step filtering method significantly reduces jump points and misdetected points in the point cloud, leading to improved navigational accuracy and stability of indoor mobile robots.