스캔 도면을 활용한 이동약자용 실내 그래프 데이터베이스 구축

학위논문(박사) -- 서울대학교대학원 : 공과대학 건설환경공학부, 2021.8. 박슬아.사람들의 실내 활동이 다양해지면서 건물의 규모가 커지고 구조가 복잡해지고 있다. 이러한 실내 환경의 변화는 교통약자의 이동성 보장에 대한 사회적 관심을 증가시켰으며, 교통약자 맞춤형 실내 라우팅 서비스에 대한 수요 또한 증가시켰다. 특히 많은 이동 제약을 가지는 이동약자 대상 서비스의 경우에는, 최적 경로를 계획하는 과정에서 개인의 선호나 경험이 반영된 개인화된 서비스로 범위가 확장되고 있다. 이러한 배경에서, 스키마가 유연하고 데이터의 가공 및 처리가 효율적인 데이터베이스의 구축이 필요하다. 본 연구에서는 스캔한 도면 이미지를 활용한 이동약자용 실내 그래프데이터베이스 구축 기법을 제안하였다. 먼저, 국내외 실내 공간 관련 표준 및 설계 기준들의 검토를 통해 이동약자의 통행과 관련된 실내 공간 및 객체, 영향 요인들을 도출하여 개념적 데이터 모델을 설계하였다. 또한, 실내의 각 공간과 시설물의 기하정보와 위상정보를 기반으로 이동약자의 접근성 및 통행 가능성을 정량화하기 위한 접근성 지수를 설계하였다. 다음으로, 스캔 도면을 입력하여 이동약자용 실내 그래프 데이터베이스 구축을 위한 프로세스를 제안하였다. 제안한 프로세스는 전이학습 기반 접근 방식을 통해 스캔 도면에서 공간의 구조 정보를 추출하고, 토폴로지 추출 및 접근성 평가를 통해 이동약자용 네트워크 모델을 생성하며, 생성한 네트워크 모델을 그래프 데이터베이스로 자동 변환하는 과정을 포함한다. 구체적으로, 제안 프로세스는 수정된 ResNet 기반의 모델을 새롭게 라벨링한 도면으로 미세 조정하여 사용함으로써 실내 구조맵을 생성한다. 이후 추출된 객체들의 공간 관계를 기반으로 각 공간을 노드와 링크로 표현한 실내 네트워크 모델을 구축한다. 각 공간의 접근성 정보는 제안된 접근성 지수와 임계값을 사용하여 생성된 후 데이터베이스에 저장되어, 이동약자를 위한 접근 가능한 그래프 추출에 활용될 수 있다. 본 연구에서는 제안한 기법을 서울대학교 도면 데이터 셋에 적용하여 이동약자용 실내 그래프 데이터베이스를 구축하고 평가하였다. 구축한 실내 그래프 데이터베이스를 활용하여 다층 경로 계획과 실내외 연계 경로 계획의 2가지 시나리오에 따라 최적 경로를 도출하였다. 그 결과, 일반 보행자의 최적 경로와 비교하여 이동약자용 최적 경로는 가까운 계단이 아닌 엘리베이터를 통한 수직 이동을 포함하였을 뿐만 아니라 접근 불가능한 공간을 회피하도록 도출되었다. 즉, 제안한 기법을 통해 이동약자 측면에서 통행 장애 정보를 포함하여 실내 환경을 적절하게 묘사하는 데이터베이스의 구축이 가능함을 확인할 수 있었다. 또한, 출입로로 명명된 관계 생성만으로 스케일이나 좌표 변환 없이 실내외 연계 경로 계획이 가능하였는데, 이는 독립적인 데이터 간 연계 사용에 적합한 그래프 데이터베이스의 특성을 반영한 결과로 판단할 수 있다. 본 연구의 주요 기여는 스캔한 도면을 사용하여 이동약자용 실내 그래프 데이터베이스를 구축하기 위한 프로세스를 개발한 것이다. 구체적으로, 이동약자의 이동에 초점을 두고 설계한 데이터 모델을 기반으로 한 데이터베이스 구축이 가능하므로 이동약자용 실내 길안내 서비스에 활용될 수 있다. 또한, 토폴로지 구축 및 그래프 데이터베이스로의 변환을 위한 하위 프로시져를 개발하였으며, 제안 프로세스는 해당 프로시져들로 구성되어 도면 입력을 통해 이동약자용 실내 그래프 데이터베이스 구축을 가능하게 한다. 해당 하위 프로시져들은 자동으로 수행될 수 있어 데이터베이스 구축 시 소요되는 시간과 비용을 절감할 수 있다. 또한, 다양한 정형 및 비정형 데이터의 연계에 적합한 그래프 데이터베이스의 특징에 의해, 제안한 프로세스를 통해 구축한 실내 데이터베이스는 기존 공간 모델의 기능을 포함하면서 다양한 유형의 길안내 서비스에 활용될 수 있을 것으로 기대된다.Changes to the indoor environment have increased social interest in ensuring the mobility of people with disabilities. Therefore, the demand for customized indoor routing services for people with mobility disabilities (PWMD), who have many travel restrictions, is increasing. These services have progressed from spatial routing to personalized routing, which reflects personal preferences and experiences in planning an optimal path. In this regard, it is necessary to generate a database for PWMD with a flexible schema suitable for the efficient manipulation and processing of data. This study aims to propose a technique of generating an indoor graph database for PWMD using scanned floor plans. First, a conceptual data model was developed by deriving relevant indoor features and influential factors, considering various international regulations on indoor environments. Also, the accessibility index was designed based on the data model to quantify the difficulties in accessing spaces based on each indoor spaces geometric characteristics. Next, a three-stage process was proposed: retrieving the structure of spaces from scanned floor plans through a transfer learning-based approach, retrieving topology and assessing accessibility for creating an indoor network model for PWMD, and converting the network model into a graph database. Specifically, an indoor structure map is created by fine-tuning the modified Resnet-based model with newly annotated floor plans for extracting structure information. Also, based on the spatial relationship of the extracted features, the indoor network model was created by abstracting indoor spaces with nodes and links. The accessibility of each space is determined by the proposed indices and thresholds; thereby, a feasible network for PWMD could be derived. Then, a process was developed for automatically converting an indoor network model, including accessibility property, into a graph database. The proposed technique was applied to the Seoul National University dataset to generate an indoor graph database for PWMD. Two scenario-based routing tests were conducted using the generated database to verify the utility of results: multi-floor routing and integrated indoor-outdoor routing. As a result, compared with the path for general pedestrians, the optimal path for PWMD was derived by avoiding inaccessible spaces, including vertical movement using elevators rather than the nearest stairs. In other words, applying the proposed technique, a database that adequately described an indoor environment in terms of PWMD with sufficient mobile constraint information could be constructed. Moreover, an integrated indoor-outdoor routing could be conducted by only creating an entrance-labeled relationship, without scale and coordinate transformation. This result reflects the usability of the generated graph database and its suitability regarding the incorporation of multiple individual data sources. The main contribution lies in the development of the process for generating an indoor graph database for PWMD using scanned floor plans. In particular, the database for PWMD routing can be generated based on the proposed data model with PWMD-related features and factors. Also, sub-procedures for topology retrieval and graph database conversion are developed to generate the indoor graph database by the end-to-end process. The developed sub-procedures are performed automatically, thereby reducing the required times and costs. It is expected that the target database of the proposed process can be generated considering utilization for various types of routing since the graph database is easily integrated with multiple types of information while covering the existing spatial models function.1. Introduction 1 1.1 Objectives and contributions 1 1.2 Related works 7 1.2.1 Indoor environment conceptualization 7 1.2.2 Indoor data construction 11 1.2.3 Accessibility assessment 19 1.3 Research scope and flow 22 2. Conceptual modeling 26 2.1 Relevant features and factors 28 2.2 Proposed data model 30 2.3 Space accessibility for PWMD 36 2.3.1 Influential factors within indoor environments 37 2.3.2 Accessibility index 41 3. Indoor graph database for PWMD from scanned floor plans 43 3.1 Retrieving structure of indoor spaces 43 3.1.1 Pre-trained model for detecting indoor geometry 45 3.1.2 Dataset with new annotation 47 3.1.3 Transfer learning-based approach 52 3.2 Generating the indoor network model for PWMD 56 3.2.1 Definition of nodes and links in the network model 60 3.2.2 The classification rule of space polygons 63 3.2.3 Connection between general spaces and doors 68 3.2.4 Node-link generation for horizontal transition spaces 71 3.2.5 Vertical link generation 75 3.2.6 Connectivity and accessibility information generation 79 3.3 Indoor graph database for PWMD 80 3.3.1 Graph representation of indoor environments 80 3.3.2 Conversion of network model into graph database 83 3.4 Entire process 87 4. Experiment and results 89 4.1 Experimental setup and test data 89 4.2 Evaluation for retrieved information 92 4.2.1 Results of structure retrieval 92 4.2.2 Results of topology retrieval 99 4.3 Generated indoor graph database for PWMD 128 4.3.1 Results of the indoor graph database for PWMD 128 4.3.2 Query-based routing 136 5. Conclusion 147 References 150 Appendix 166 국문초록 178박

A System-driven Automatic Ground Truth Generation Method for DL Inner-City Driving Corridor Detectors

Data-driven perception approaches are well-established in automated driving systems. In many fields even super-human performance is reached. Unlike prediction and planning approaches, mainly supervised learning algorithms are used for the perception domain. Therefore, a major remaining challenge is the efficient generation of ground truth data. As perception modules are positioned close to the sensor, they typically run on raw sensor data of high bandwidth. Due to that, the generation of ground truth labels typically causes a significant manual effort, which leads to high costs for the labelling itself and the necessary quality control. In this contribution, we propose an automatic labeling approach for semantic segmentation of the drivable ego corridor that reduces the manual effort by a factor of 150 and more. The proposed holistic approach could be used in an automated data loop, allowing a continuous improvement of the depending perception modules.Comment: 8 page

Comparison of Arterial-Level Signal Coordination Features of Five Selected Software Programs

Synchro, PTV Vistro, TransModeler, Tru-Traffic, and TranSync are software programs that are part of different software packages that can all be used for traffic signal coordination tasks in countries that use ring-barrier signal controllers. Each program has different functions, features, inputs and outputs. Synchro, Vistro, and TransModeler all require volume inputs to make an analysis while Tru-Traffic and TranSync do not require volumes. These five programs were compared on the basis of their ability to assist the engineer in designing an optimized arterial coordination timing plan, which included automatic optimization, editing and viewing information presented on the time-space diagram, and selecting various timing plans and intersections to show the time-space diagram.The same arterial was modeled in all five programs and phase sequence and offset default optimization functions were executed separately for Synchro, Vistro, Tru-Traffic and TranSync. The average vehicle travel time and average number of vehicle stops were simulated using TransModeler, a third-party traffic simulation program to ensure results are not biased. Results showed that Synchro and Tru-Traffic had the lowest peak direction travel time through the whole arterial and the least number of stops. The optimization produced by Vistro and TranSync was 1 minute or 10% slower for the peak direction average travel time than Synchro and Tru-Traffic, which were tied. The southbound travel time for the optimization produced by Vistro was very similar to TranSync, but TranSync had the shortest northbound travel time. The northbound travel time from TranSync was 10% or 1 minute faster than the slowest off-peak (northbound) optimization which was performed by Vistro. TranSync had the greatest number of features for the time-space diagram and timing plan options compared to the other four programs.This research reviewed the features of each software package so practitioners can make a better educated decision on which program they would like to use. Using the right tool for the task can save project resources (time, budget, etc.) and contribute to efficiently designed timing plans