A Flexible Modeling Approach for Robust Multi-Lane Road Estimation

A robust estimation of road course and traffic lanes is an essential part of environment perception for next generations of Advanced Driver Assistance Systems and development of self-driving vehicles. In this paper, a flexible method for modeling multiple lanes in a vehicle in real time is presented. Information about traffic lanes, derived by cameras and other environmental sensors, that is represented as features, serves as input for an iterative expectation-maximization method to estimate a lane model. The generic and modular concept of the approach allows to freely choose the mathematical functions for the geometrical description of lanes. In addition to the current measurement data, the previously estimated result as well as additional constraints to reflect parallelism and continuity of traffic lanes, are considered in the optimization process. As evaluation of the lane estimation method, its performance is showcased using cubic splines for the geometric representation of lanes in simulated scenarios and measurements recorded using a development vehicle. In a comparison to ground truth data, robustness and precision of the lanes estimated up to a distance of 120 m are demonstrated. As a part of the environmental modeling, the presented method can be utilized for longitudinal and lateral control of autonomous vehicles

Multi-Lane Perception Using Feature Fusion Based on GraphSLAM

An extensive, precise and robust recognition and modeling of the environment is a key factor for next generations of Advanced Driver Assistance Systems and development of autonomous vehicles. In this paper, a real-time approach for the perception of multiple lanes on highways is proposed. Lane markings detected by camera systems and observations of other traffic participants provide the input data for the algorithm. The information is accumulated and fused using GraphSLAM and the result constitutes the basis for a multilane clothoid model. To allow incorporation of additional information sources, input data is processed in a generic format. Evaluation of the method is performed by comparing real data, collected with an experimental vehicle on highways, to a ground truth map. The results show that ego and adjacent lanes are robustly detected with high quality up to a distance of 120 m. In comparison to serial lane detection, an increase in the detection range of the ego lane and a continuous perception of neighboring lanes is achieved. The method can potentially be utilized for the longitudinal and lateral control of self-driving vehicles

From 11% Thin Film to 23% Heterojunction Technology (HJT) PV Cell: Research, Development and Implementation Related 1600 × 1000 mm2 PV Modules in Industrial Production

Plasma-enhanced chemical vapor deposition (PECVD) developed for thin film (TF) Si:H-based materials resulted in large area thin film PV cells on glass and flexible substrates. However, these TF cells demonstrate low power conversion efficiency PCE = 11% for double and PCE = 13% for triple junction cells below predicted PCE ≈ 24%. PV cells on crystalline silicon (c-Si) provide PCE ≈ 17–19%. Cost of c-Si PV cells lowered continuously due to reducing price of silicon wafers and enlarging their size. Two factors stimulated a combination of PECVD films and c-Si devices: (a) compatibility of the technologies and (b) possibility for variation of electronic properties in PECVD materials. The latter results in additional build-in electric fields improving charge collection and harvesting solar spectrum. We describe a transformation of PECVD TF solar cell technology for 11% efficiency modules to heterojunction technology (HJT) c-Si modules with 23% efficiency. HJT PV structure comprises c-Si wafer with additional junctions created by PECVD deposited layers allowing development of single wafer PV cells with PCE ≈ 24% and the size limited by wafer (15.6 x 15.6 cm2). The chapter starts with background in PECVD and c-Si PV cells. Then, in Section 2, we describe electronic properties of PECVD materials in HJT PV structures. Section 3 deals with structure and fabrication process for HJT devices. In Section 4, we present and discuss performance characteristics of the devices. Section 5 describes implementation of the developed HJT module (1600 x 1000 mm2) based on HJT single wafer cells in industry with presentation and discussion of characteristics related to industrial production. Finally, Section 6 presents the outlook and summary of the chapter

A novel real-time edge-preserving smoothing filter

The segmentation of textured and noisy areas in images is a very challenging task due to the large variety of objects and materials in natural environments, which cannot be solved by a single similarity measure. In this paper, we address this problem by proposing a novel edge-preserving texture filter, which smudges the color values inside uniformly textured areas, thus making the processed image more workable for color-based image segmentation. Due to the highly parallel structure of the method, the implementation on a GPU runs in realtime, allowing us to process standard images within tens of milliseconds. By preprocessing images with this novel filter before applying a recent real-time color-based image segmentation method, we obtain significant improvements in performance for images from the Berkeley dataset, outperforming an alternative version using a standard bilateral filter for preprocessing. We further show that our combined approach leads to better segmentations in terms of a standard performance measure than graph-based and mean-shift segmentation for the Berkeley image dataset.Peer ReviewedPostprint (author’s final draft

3d semantic representation of actions from effcient stereo-image-sequence segmentation on GPUs

A novel real-time framework for model-free stereo-video segmentation and stereo-segment tracking is presented, combining real-time optical flow and stereo with image segmentation running separately on two GPUs. The stereosegment tracking algorithm achieves a frame rate of 23 Hz for regular videos with a frame size of 256 x 320 pixels and nearly real time for stereo videos. The computed stereo segments are used to construct 3D segment graphs, from which main graphs, representing a relevant change in the scene, are extracted, which allow us to represent a movie of e.g. 396 original frames by only 12 graphs, each containing only a small number of nodes, providing a condensed description of the scene while preserving data-intrinsic semantics. Using this method, human activities, e.g., handling of objects, can be encoded in an efficient way. The method has potential applications for manipulation action recognition and learning, and provides a vision-front end for applications in cognitive robotics.Postprint (published version

On the kinetics of high intensity illuminated annealing of n-type SHJ solar cells: 0.4%abs efficiency gain in one second

Silicon heterojunction (SHJ) solar cells are at the forefront of high efficiency industrial solar cell manufacturing. The rapid increase in efficiency compared with passivated emitter and rear cell (PERC) cells has significantly propelled commercial interest in this technology. Illuminated annealing under elevated temperatures has been shown to lead to efficiency enhancements in SHJ cells. Recently, it was observed that increasing the light intensity used during the annealing can accelerate the efficiency gains, this approach has started to be incorporated into SHJ manufacturing. In this work, we investigate the kinetics of this high intensity illuminated annealing process in the temperature range from 200 °C to 300 °C, demonstrating that the kinetics and extent of the efficiency gain strongly depend on the temperature of the process. For the first time, we show that the changes in VOC and RS, which control the efficiency enhancement, occur at different rates. Remarkably, by investigating the temperature dependence we demonstrate a process that leads to efficiency gains of >0.4%abs in only 1 s. This new understanding presents a pathway to an industrially compatible annealing approach that significantly increases the power output of SHJ modules

Синтез енергоефективного закону управління розгоном автомобіля

We have established the laws of change in the vehicle acceleration time at the existing step transmission of ICE, when implementing the total traction force, boundary for the drive wheels adhesion to the road, and during implementation of the proposed rational law for acceleration control. To model ICE speed characteristics, we applied the empirical dependence by S.R. Leyderman. The analytical expressions obtained allow us to implement such a change in vehicle acceleration depending on its speed that makes it possible to ensure maximum dynamism at minimal engine power consumption, taking into consideration a nonlinear change in external resistance. The maximum acceleration, which is possible to implement using the rational dynamic characteristic, can reach 7 m/s2. Based on the dependences obtained, it is possible to determine effective work of ICE required to accelerate a vehicle at different gears. An analysis of calculation results revealed that the transition from lower to higher gears is accompanied by a sharp decrease in engine energy expenditure required to accelerate the vehicle.It was established that for the case of hybrid vehicles, acceleration using the electric drive, rather than accelerating at lower gears of the mechanical drive, makes it possible to reduce energy losses by 20 % (for a four-cylinder internal combustion engine). Energy preservation is accomplished by reducing the fluctuation of traction force, as well as the possibility of a step-free change in motion speed.Определена рациональная динамическая характеристика автомобиля, позволяющая разгон при минимальных затратах энергии двигателя. Определены законы изменения времени разгона автомобиля при реализации предельной по сцеплению ведущих колес с дорогой суммарной тяговой силы и при реализации предложенного рационального закона управления ускорением. Проведена оценка эффективной работы ДВС при разгоне на различных передачах автомобиляВизначена раціональна динамічна характеристика автомобіля, що дозволяє розгін при мінімальних витратах енергії двигуна. Визначено закони зміни часу розгону автомобіля при реалізації граничної по зчепленню ведучих коліс з дорогою сумарної тягової сили й при реалізації запропонованого раціонального закону управління прискоренням. Проведена оцінка ефективної роботи ДВЗ при розгоні на різних передачах автомобіл