Charles A. Otto

Rail Component Detection, Optimization, and Assessment for Automatic Rail Track Inspection

In this paper, we present a real-time automatic vision-based rail inspection system, which performs inspections at 16 km/h with a frame rate of 20 fps. The system robustly detects important rail components such as ties, tie plates, and anchors, with high accuracy and efficiency. To achieve this goal, we first develop a set of image and video analytics and then propose a novel global optimization framework to combine evidence from multiple cameras, Global Positioning System, and distance measurement instrument to further improve the detection performance. Moreover, as the anchor is an important type of rail fastener, we have thus advanced the effort to detect anchor exceptions, which includes assessing the anchor conditions at the tie level and identifying anchor pattern exceptions at the compliance level. Quantitative analysis performed on a large video data set captured with different track and lighting conditions, as well as on a real-time field test, has demonstrated very encouraging performance on both rail component detection and anchor exception detection. Specifically, an average of 94.67% precision and 93% recall rate has been achieved for detecting all three rail components, and a 100% detection rate is achieved for compliance-level anchor exception with three false positives per hour. To our best knowledge, our system is the first to address and solve both component and exception detection problems in this rail inspection area.

Enhanced rail component detection and consolidation for rail track inspection

For safety purposes, railroad tracks need to be inspected on a regular basis for physical defects or design noncompliances. Such track defects and non-compliances, if not detected in a timely manner, may eventually lead to grave consequences such as train derailments. In this paper, we present a real-time automatic vision-based rail inspection system, with main focus on anchors - an important rail component type, and anchor-related rail defects, or exceptions. Our system robustly detects important rail components including ties, tie plates, anchors with high accuracy and efficiency. Detected objects are then consolidated across video frames and across camera views to map to physical rail objects, by combining the video data streams from all camera views with GPS information and speed information from the distance measuring instrument (DMI). After these rail components are detected and consolidated, further data integration and analysis is followed to detect sequence-level track defects, or exceptions. Quantitative analysis performed on a real online field test conducted on different track conditions demonstrates that our system achieves very promising performance in terms of rail component detection, anchor condition assessment, and compliance-level exception detection. We also show that our system outperforms another advanced rail inspection system in anchor detection.

Component-based track inspection using machine-vision technology

In this paper, we present our latest research engagement with a railroad company to apply machine vision technologies to automate the inspection and condition monitoring of railroad tracks. Specifically, we have proposed a complete architecture including imaging setup for capturing multiple video streams, important rail component detection such as tie plate, spike, anchor and joint bar bolt, defect identification such as raised spikes, defect severity analysis and temporal condition analysis, and long-term predictive assessment. This paper will particularly present various video analytics that we have developed to detect rail components, which form the building block of the entire framework. Our preliminary performance study has achieved an average of 98.2% detection rate, 1.57% false positive rate and 1.78% false negative rate on the component detection. Finally, with the lack of sufficient representative data and annotations to evaluate system performance on exception detection at both sequence and compliance levels, we proposed a mathematical modeling approach to calculate the probabilities of detecting such exceptions. Such analysis shows that there is still big room for us to improve our approaches in order to achieve desired false positive rate and miss detection rate at the sequence level.

Visual item verification for fraud prevention in retail self-checkout

Many modern retail stores have self-checkout stations where customers can ring up their own orders without the assistance of any store personnel. To promote customer honesty these systems often weigh each item as it is placed in the bag to confirm that it has the expected mass for the product scanned. In our system we augment this basic check with an assessment of the items visual appearance to further ensure that the correct code has been entered.

Cart Auditor: A Compliance and Training Tool for Cashiers at Checkout

Shopping carts have traditionally been used as a tool provided to the customers in retail stores to carry items from the shelf to checkout stations. These days shopping carts can also be used as a security checkpoint to prevent store losses. All the items collected in a shopping cart are supposed to be unloaded at the checkout station to be scanned and included in the bill. Any items left in the cart intentionally or by accident will not be charged and therefore cause a loss to the store. We propose a system that automatically detects shopping carts and verify their emptiness at the checkout station. We use motion segmentation, line detection, and template matching methods for the cart detection and emptiness verification. An inter-frame edge difference, cart’s path accumulator, and a finite state model are introduced for accurate cart detection. All detected carts are compared with empty cart models and the dissimilarity scores are calculated to verify the emptiness. The proposed system was evaluated on a long video clip (~12 hours) and showed promising results both in cart detection and emptiness verification.