A Novel Gaussian Process Based Ground Segmentation Algorithm with Local-Smoothness Estimation

Abstract

Autonomous Land Vehicles (ALV) shall efficiently recognize the ground in unknown environments. A novel GPbased method is proposed for the ground segmentation task in rough driving scenarios. The non-stationary covariance function proposed by [1] is utilized as the kernel for the GP. The ground surface behavior is assumed to only demonstrate local-smoothness. Thus, point estimates of the kernel's length-scales are obtained. Thus, two Gaussian processes are introduced to separately model the observation and local characteristics of the data. While, the observation process is used to model the ground, the latent process is put on lengthscale values to estimate point values of length-scales at each input location. Input locations for this latent process are chosen in a physically-motivated procedure to represent an intuition about ground condition. Furthermore, an intuitive guess of length-scale value is represented by assuming the existence of hypothetical surfaces in the environment that every bunch of data points may be assumed to be resulted from measurements from this surfaces. Bayesian inference is implemented using maximum a Posteriori criterion. The log-marginal likelihood function is assumed to be a multitask objective function, to represent a whole-frame unbiased view of the ground at each frame. Simulation results shows the effectiveness of the proposed method even in an uneven, rough scene which outperforms similar Gaussian process based ground segmentation methods. While adjacent segments do not have similar ground structure in an uneven scene, the proposed method gives an efficient ground estimation based on a whole-frame viewpoint instead of just estimating segmentwise probable ground surfaces.

Comparison of Object Region Segmentation Algorithms of PCB Defect Detection

“…In order to meet the real-time requirements of defect detection, the segmentation algorithm should be accurate and fast and minimize the complexity [17][18][19]. After analyzing three types of image segmentation algorithms, namely, color space threshold segmentation, morphological edge detection segmentation, and K-means clustering segmentation, these algorithms were used to segment PCB images.…”