The barcode navigation based on QR (quick response) codes is widely employed in industrial logistics due to its accurate localization and flexible movement paths. However, the regular repair of damaged barcodes and robot speed control when approaching the barcodes are required. In this study, we presented an improved magnetic spot navigation approach to replace the barcode navigation for automated guided vehicles (AGVs). The fusion of the high-precision magnetic tracking method and odometer based on AGV encoders can overcome the disadvantages of barcode navigation. The magnetic tracking approach provides the AGV pose relative to the nearest magnet spot, instead of the low-precision longitudinal and lateral measurement via a magnetic ruler. Besides, with the benefit of the adaptive weighted fusion algorithm, the distance between the adjacent barcode can be set from 500 to 1000 mm via magnetic spots. Experimental results show that the mean path accuracy and mean magnet spot localization accuracy of the improved magnetic spot navigation were 110 ± 30 mm and 14.5 ± 0.87 mm, respectively. The proposed approach provides a novel possibility for large-area and high-precision navigation in AGVs-based industrial logistics, especially for large outdoor scenarios.

A mobile robot that follows behind humans in structured environments has to face the challenge of full occlusion caused by the walls when the target person makes a turn at the corridor intersections. This may result in short-term, even a permanent loss of the target from the field of view of the Human-Following Robots (HFRs). Concerning this issue, a novel side-by-side following method for HFRs is addressed. In this paper, HFRs detect the legs of target person and different types of corridor intersections using the onboard laser scanner at first. Then, we provide a corridor detector method to cluster the geometric structure constraint between the target and corridor intersections. At last, a Side-by-side Following Leg Tracker (SFLT) is designed by integrating the laser information, in order to increase the visible time of the target person, while the target is turning at the corridor intersections. The corridor detector method and SFLT method have been simulated in MATLAB. Moreover, the approach of side-by-side following has been implemented in the Robot Operating System (ROS) of real-life robots in the corridor environment. The results from simulation and practical experiment show that, by using our method, HFRs were able to successfully follow the human92.0% while a mobile robot meeting potential occlusions at corridor intersections.

Mixed land use has been widely used as a planning tool to improve the functionality of cities. However, depicting mixed land use is rather difficult due to its complexities. Previous studies have decomposed urban land areas using either remote sensing images or geospatial big data. Few studies have combined these two data sources because of the lack of methodologies. This article proposed an end-to-end two-stream convolutional neural network (CNN) for combining features (CF-CNN) to estimate the proportion of mixed land use by integrating high spatial resolution (HSR) images and geospatial big data of real-time Tencent user density (RTUD) data. Two deep learning networks, one for image information extraction and other for human activity-related information extraction, are used to construct two branches of CF-CNN. The mixed land use can be described by calculating the proportions of each land use type at the street-block level. Compared with methods for using single-source data, CF-CNN obtained the highest classification accuracy. We further applied the Shannon diversity index (SHDI) to quantify the agglomerated urban mixed land use. The Spearman correlation coefficients among the SHDI, community distance, and neighborhood vibrancy were calculated to verify the effectiveness of the mixed land use composition. Our framework provided an alternative way of identifying mixed land use structures by integrating multisource data.

Change detection methods based on low-resolution (LR) images with higher temporal resolution often lead to fuzzy results, while high-resolution images (HRIs) can provide more detailed information to solve this problem. However, it's hard to obtain two tiles of HRIs with high-quality for rapid change detection in actual production due to low temporal resolution and high cost. Therefore, it is necessary to explore a change detection method combing low- and high-resolution images to acquire urban change areas more accurately and quickly. In this paper, an end-to-end siamese generative adversarial network (SiamGAN) integrating a super resolution network and the siamese structure was proposed for change detection under different scales. The super-resolution network is used to reconstruct low-resolution images into high-resolution images, while the siamese structure is adopted as the classification network to detect changes. In the experiments, SiamGAN achieved an F1 of 76.06% and an IoU of 61.52% in the test set, which is respectively 5.68% and 6.92% higher than the CNN-based methods using LR images after bicubic interpolation. The results show that our proposed method can effectively overcome difference in scale between low- and high-resolution images and perform change detection more precisely and rapidly.

Urban villages (UVs) are distinctive products formed in the process of rapid urbanization. The fine-grained mapping of UVs from satellite images has always been a considerable challenge because of the complex urban structures and the insufficiency of labeled samples. In this letter, we propose using the domain adaptation strategy to tackle the domain shift problem by employing adversarial learning to tune the semantic segmentation network so as to adaptively obtain similar outputs for input images from different domains. The proposed method was coupled with several segmentation networks, including U-Net, RefineNet, and DeepLab v3+, and the results show that domain adaptation can significantly improve the pixel-level mapping of UVs.

Though global-coverage urban perception datasets have been recently created using machine learning, their efficacy in accurately assessing local urban perceptions for other countries and regions remains a problem. Here we describe a human-machine adversarial scoring framework using a methodology that incorporates deep learning and iterative feedback with recommendation scores, which allows for the rapid and cost-effective assessment of the local urban perceptions for Chinese cities. Using the state-of-the-art Fully Convolutional Network (FCN) and Random Forest (RF) algorithms, the proposed method provides perception estimations with errors less than 10%. The driving factor analysis from both the visual and urban functional aspects demonstrated its feasibility in facilitating local urban perception derivations. With high-throughput and high-accuracy scorings, the proposed human-machine adversarial framework offers an affordable and rapid solution for urban planners and researchers to conduct local urban perception assessments.

Cellular automata (CA) have been widely used to simulate complex urban development processes. Previous studies indicated that vector-based cellular automata (VCA) could be applied to simulate urban land-use changes at a realistic land parcel level. Because of the complexity of VCA, these studies were conducted at small scales or did not adequately consider the highly fragmented processes of urban development. This study aims to build an effective framework called dynamic land parcel subdivision (DLPS)-VCA to accurately simulate urban land-use change processes at the land parcel level. We introduce this model in urban land-use change simulations to reasonably divide land parcels and introduce a random forest algorithm (RFA) model to explore the transition rules of urban land-use changes. Finally, we simulate the land-use changes in Shenzhen between 2009 and 2014 via the proposed DLPS-VCA model. Compared to the advanced Patch-CA and RFA-VCA models, the DLPS-VCA model achieves the highest simulation accuracy (Figure-of-Merit = 0.232), which is 32.57% and 18.97% higher respectively, and is most similar to the actual land-use scenario (similarity = 94.73%) at the pattern level. These results indicate that the DLPS-VCA model can both accurately split the land during urban land-use changes and significantly simulate urban expansion and urban land-use changes at a fine scale. Furthermore, the land-use change rules that are based on DPLS-VCA mining and the simulation results of several future urban development scenarios can act as guides for future urban planning policy formulation.

Urban land use information plays an essential role in a wide variety of urban planning and environmental monitoring processes. During the past few decades, with the rapid technological development of remote sensing (RS), geographic information systems (GIS) and geospatial big data, numerous methods have been developed to identify urban land use at a fine scale. Points-of-interest (POIs) have been widely used to extract information pertaining to urban land use types and functional zones. However, it is difficult to quantify the relationship between spatial distributions of POIs and regional land use types due to a lack of reliable models. Previous methods may ignore abundant spatial features that can be extracted from POIs. In this study, we establish an innovative framework that detects urban land use distributions at the scale of traffic analysis zones (TAZs) by integrating Baidu POIs and a Word2Vec model. This framework was implemented using a Google open-source model of a deep-learning language in 2013. First, data for the Pearl River Delta (PRD) are transformed into a TAZ-POI corpus using a greedy algorithm by considering the spatial distributions of TAZs and inner POIs. Then, high-dimensional characteristic vectors of POIs and TAZs are extracted using the Word2Vec model. Finally, to validate the reliability of the POI/TAZ vectors, we implement a K-Means-based clustering model to analyze correlations between the POI/TAZ vectors and deploy TAZ vectors to identify urban land use types using a random forest algorithm (RFA) model. Compared with some state-of-the-art probabilistic topic models (PTMs), the proposed method can efficiently obtain the highest accuracy (OA = 0.8728, kappa = 0.8399). Moreover, the results can be used to help urban planners to monitor dynamic urban land use and evaluate the impact of urban planning schemes.