778 research outputs found

    A Comparison Between Coupled and Decoupled Vehicle Motion Controllers Based on Prediction Models

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    In this work, a comparative study is carried out with two different predictive controllers that consider the longitudinal jerk and steering rate change as additional parameters, as additional parameters, so that comfort constraints can be included. Furthermore, the approaches are designed so that the effect of longitudinal and lateral motion control coupling can be analyzed. This way, the first controller is a longitudinal and lateral coupled MPC approach based on a kinematic model of the vehicle, while the second is a decoupled strategy based on a triple integrator model based on MPC for the longitudinal control and a double proportional curvature control for the lateral motion control. The control architecture and motion planning are exhaustively explained. The comparative study is carried out using a test vehicle, whose dynamics and low-level controllers have been simulated using the realistic simulation environment Dynacar. The performed tests demonstrate the effectiveness of both approaches in speeds higher than 30 km/h, and demonstrate that the coupled strategy provides better performance than the decoupled one. The relevance of this work relies in the contribution of vehicle motion controllers considering the comfort and its advantage over decoupled alternatives for future implementation in real vehicles.This work has been conducted within the ENABLE-S3 project that has received funding from the ECSEL Joint Undertaking under Grant Agreement No 692455. This work was developed at Tecnalia Research & Innovation facilities supporting this research

    A Two-Stage Real-Time Path Planning: Application to the Overtaking Manuever

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    This paper proposes a two-stage local path planning approach to deal with all kinds of scenarios (i.e. intersections, turns, roundabouts). The first stage carries out an off-line optimization, considering vehicle kinematics and road constraints. The second stage includes all dynamic obstacles in the scene, generating a continuous path in real-time. Human-like driving style is provided by evaluating the sharpness of the road bends and the available space among them, optimizing the drivable area. The proposed approach is validated on overtaking scenarios where real-time path planning generation plays a key role. Simulation and real results on an experimental automated platform provide encouraging results, generating real-time collision-free paths while maintaining the defined smoothness criteria.INRIA and VEDECOM Institutes under the Ph.D. Grant; 10.13039/501100011688-Electronic Components and Systems for European Leadership (ECSEL) Project AutoDriv

    Optimized trajectory planning for Cybernetic Transportation Systems

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    International audienceThis paper describes the development of an optimized path planning algorithm for automated vehicles in urban environments. This path planning is developed on the basis of urban environments, where Cybernetic Transportation Systems (CTS) will operate. Our approach is mainly affected by vehicle's kinematics and physical road constraints. Based on this assumptions, computational time for path planning can be significantly reduced by creating an off-line database that already optimized all the potential trajectories in each curve the CTS can carry out. Therefore, this algorithm generates a database of smooth and continuous curves considering a big set of different intersection scenarios, taking into account the constraints of the infrastructure and the physical limitations of the vehicle. According to the real scenario, the local planner selects from the database the appropriate curves from searching for the ones that fit with the intersections defined on it. The path planning algorithm has been tested in simulation using the previous control architecture. The results obtained show path generation improvements in terms of smoothness and continuity. Finally, the proposed algorithm was compared with previous path planning algorithms for its assessment

    Dynamically integrated spatiotemporal-based trajectory planning and control for autonomous vehicles

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    In the literature, the intensive research effort has been made on the trajectory planning for autonomous vehicles, while the integration of the trajectory planner with the trajectory controller is less focused. This study proposes the spatiotemporal-based trajectory planner and controller by a two-level dynamically integrated structure. In the upper level, the best trajectory is selected among a group of candidate time-parameterised trajectories, while the target vehicle ending position and velocity can be satisfied. Then the planned trajectory is evaluated by checking the feasibility when the actual vehicle dynamic motion constraints are considered. After that, the lower level trajectory controller based on the vehicle dynamics model will control the vehicle to follow the desired trajectory. Numerical simulations are used to validate the effectiveness of the proposed approach, where the scenario of an intersection and the scenario of overtaking are applied to show that the proposed trajectory controller can successfully achieve the control targets. In addition, compared with the potential field method, the proposed method based on the four-wheel independent steering and four-wheel independent driving electric vehicle shows great advantages in guaranteeing the vehicle handling and stability

    Real-time planning for adjacent consecutive intersections

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    International audienceReal-time path planning constitutes one of the hot topics when developing automated driving. Different path planning techniques have been studied in both the robotics and automated vehicles fields trying to improve the trajectory generation and its tracking. In this paper, a novel local path planning algorithm combining both off-line and real-time generation for automated vehicles in urban environments is presented. It takes advantage of an off-line planning strategy to achieve a smooth and continuous trajectory generation with adjacent consecutive intersections. Therefore, this approach allows a smooth and continuous trajectory by means of planning consecutive curves concurrently, i.e., it will plan the upcoming curve and the following one in advance, taking into account the constraints of the infrastructure and the physical limitations of the vehicle. The real-time planning algorithm has been tested in simulation based on the INRIA-RITS vehicles architecture. The results obtained show an improvement in the smoothness, continuity and comfort of the generated paths

    Futures of Lisbon: transportation, mobility and accessibility

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    Physical mobility needs energy: this is an unquestionable platitude. The hydrocarbons that have so strongly conditioned life in the last century have allowed a growing percentage of humankind to make disruptive dreams of dizzying speeds, and have induced "modern" urbanized societies to quasi-comatose states of drunkenness from consuming cheap energy. A little man will not have a clear conscience over this, but a Big Man has an obligation to integrate in his calculations the basic assumption that three tablespoons of crude is sufficient to obtain the energy of eight hours of manual labour, and that the energy present in the full fuel tank of a motor vehicle is equivalent to two years of "blood motor" activity that we are made of. It is therefore reasonable for the Little Big Man to choose the notion of "energy crisis" as a problematic pillar of analysis.info:eu-repo/semantics/acceptedVersio

    Shrinking Spaces and Emerging Role of Information Technology in India

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    The ever expanding Indian cities and its population from 27 million from early 20th century to 377 million in early 21st century put forth a challenge for urban planners and managers to solve complex integrated problems and to design smart sustainable cities. Even in near future the scale of problem will be going to rise as it is estimated that about 50 percent of total Indian population, which is about 814 million person, will be living in Indian cities by 2050. Moreover, the fastest growing or changing Information Technologies are playing a greater role in transformation of urban spaces in Indian cities. Hence, the present paper is an attempt to analyse the impact of Information Technologies in transformation of urban planning process in India. The paper, in relation with the case study of Delhi, analyse the implication of IT on city structure and urban spaces. It is certain the all aspects of urban fabric have an Information Technological print in different magnitudes and scale. Cybernetic age has given us different life style, working pattern and mobility behaviour. Increasing speed of internet from 2G to 3G, 4G and even 5G; from participatory interactive Web 2.0 technologies to Web 3.0, 4.0 technology; shrinking physical spaces of financial banks from whole building to Sq. meter, Sq. feet (ATM), inches (laptop), cm (Mobile), even mm (intelligent banking chip). Such technological, social, physical and economical changes will raise many question in the mind of planner, like is the functional boundaries of cities will vanish? Is IT will bridge the gap or create the digital divide among urban community? Is IT shrinking the urban spaces or not? After analysing the Indian urban and IT policy and understanding the Delhi Urban structure, the present paper tries to answer these questions. By understanding the existing complex settlement interdependence the present paper also recommends the possible solutions that IT may facilitate or hasten the development and, whether it needs to be treated as process and not an end. Finally the paper proves the hypothesis that “IT will shrink the space by eliminating the factor of time and distance by creating virtual space, but in reality it will make urban functional boundaries to sprawl and thus expand the physical urban space”

    Dynamic Trajectory Generation Using Continuous-Curvature Algorithms for Door to Door Assistance Vehicles

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    International audienceIn this paper, an algorithm for dynamic path generation in urban environments is presented, taking into account structural and sudden changes in straight and bend segments (e.g. roundabouts and intersections). The results present some improvements in path generation (previously hand plotted) considering parametric equations and continuous-curvature algorithms, which guarantees a comfortable lateral acceleration. This work is focused on smooth and safe path generation using road and obstacle detection information. Finally, some simulation results show a good performance of the algorithm using different ranges of urban curves. The main contribution is an Intelligent Trajectory Generator, which considers infrastructure and vehicle information. This method is recently used in the framework of the project CityMobil2, for urban autonomous guidance of Cybercars
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