| 1. |
- Yu, Yushu, 1985, et al.
(författare)
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Formally Robust and Safe Trajectory Planning and Tracking for Autonomous Vehicles
- 2022
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Ingår i: IEEE Transactions on Intelligent Transportation Systems. - 1524-9050 .- 1558-0016. ; 23:12, s. 22971-22987
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a safe trajectory planning and tracking algorithm for autonomous vehicles is proposed. Specially, the safety problem considers the geometric constraints including the obstacle avoiding and the road side constraints, and the non-convex input constraints defined from the sideslip angle of the wheels and input boundedness. Control barrier function (CBF) is adopted to deal with the state and input constraints and generate nominal trajectory. For this purpose, the nominal dynamics of the autonomous vehicle is defined as the virtual dynamics, from which the CBF safety certificates are derived. By constructing appropriate feedback control, the tracking error of the actual trajectory can be bounded into a tube, which guarantees the geometric safety of the actual vehicle. Two safety certificates, the bearing and the distance safety certificates are derived for multiple-obstacle avoidance. In order to deal with the non-convex input constraints, a safe braking maneuver is carefully considered. The feasible initial velocity set for safe braking is proposed as a part of state constraints. The feasibility and the safety of the overall system is proved. The algorithm to synthesis the CBF certificates for multiple-obstacle avoidance, and the input constraints is proposed. Simulation results from an autonomous vehicle including disturbances demonstrate the feasibility of the algorithm. The software implementation of the proposed algorithm was developed in C++ intended for real-world testing.
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| 2. |
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| 3. |
- Benderius, Ola, 1985, et al.
(författare)
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A simulation environment for analysis and optimization of driver models
- 2011
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Ingår i: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics). - Berlin, Heidelberg : Springer Berlin Heidelberg. - 1611-3349 .- 0302-9743. - 9783642217982 ; 6777, s. 453-462
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Konferensbidrag (refereegranskat)abstract
- A simulation environment for evaluation and optimization of driver models is introduced and described. The simulation environment features models of vehicles and drivers, as well as a representation of the traffic environment (roads, buildings etc.). In addition, an optimization framework based on stochastic optimization algorithms has been implemented as an integral part of the simulation environment. Given observed (time series) data of driver behavior and, possibly, vehicle dynamics, the optimization framework can be used for inferring driver model parameters. The simulation environment has been evaluated in two scenarios, one involving emergency braking and one involving a double lane change.
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| 4. |
- Benderius, Ola, 1985, et al.
(författare)
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Are we ready for beyond-application high-volume data? The Reeds robot perception benchmark dataset
- 2021
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents a dataset, called Reeds, for research on robot perception algorithms. The dataset aims to provide demanding benchmark opportunities for algorithms, rather than providing an environment for testing application-specific solutions. A boat was selected as a logging platform in order to provide highly dynamic kinematics. The sensor package includes six high-performance vision sensors, two long-range lidars, radar, as well as GNSS and an IMU. The spatiotemporal resolution of sensors were maximized in order to provide large variations and flexibility in the data, offering evaluation at a large number of different resolution presets based on the resolution found in other datasets. Reeds also provides means of a fair and reproducible comparison of algorithms, by running all evaluations on a common server backend. As the dataset contains massive-scale data, the evaluation principle also serves as a way to avoid moving data unnecessarily. It was also found that naive evaluation of algorithms, where each evaluation is computed sequentially, was not practical as the fetch and decode task of each frame would not scale well. Instead, each frame is only decoded once and then fed to all algorithms in parallel, including for GPU-based algorithms.
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| 5. |
- Benderius, Ola, 1985, et al.
(författare)
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Driver behaviour in unexpected critical events and in repeated exposures – a comparison
- 2014
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Ingår i: European Transport Research Review. - : Springer Science and Business Media LLC. - 1867-0717 .- 1866-8887. ; 6:1, s. 51-60
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Tidskriftsartikel (refereegranskat)abstract
- PurposeThis paper aims to determine how truck driver steering behaviour seen in repeated exposures to acritical event correlates to the behaviour resulting from an unexpected exposure to the same event.MethodsTest subjects were exposed to an unexpected critical event in a high-fidelity driving simulator. Next, a slightly modified version of the scenario was repeated several times for each subject. The driver behaviour was then analysed using standard statistical tests.ResultsIt was found that, in general, drivers keep most of their steering behaviour characteristics between test settings (unexpected and repeated). This is particularly interesting sincea similar kind of behaviour preservation is generally not found in the case of braking behaviour. In fact, onlyone significant difference was found between the two test settings, namely regarding time-to-collision at steering initiation.ConclusionsIn experiments involving both an unexpected event and several repeated events one can,at least in some cases, design the repeated event such that behavioural data collected from that setting can beused along with data from the unexpected setting. Using this procedure, one can significantly increase the amount of collected data, something that can strongly benefit, for example, driver modelling.
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| 6. |
- Benderius, Ola, 1985
(författare)
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Driver modeling: Data collection, model analysis, and optimization
- 2012
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis concerns aspects of driver modeling, with an emphasis on critical near-crash scenarios, involving time spans of around 10 s of driving. Here,driver modeling has been studied using both computer simulations and experiments carried out in a high-fidelity driving simulator. A computer simulation environment has been developed especially for driver modeling. This simulation environment includes a stochastic optimization method for model parameter tuning. Moreover, a review of existing driver models has been carried out. In many cases in the literature, new driver models have been proposed without comparison with existing models. Many models also lackproper validation against driving data. A possible explanation may be that such data are expensive and difficult to collect, especially in critical scenarios.However, in this thesis, the results obtained in a driving simulator study involving a collision avoidance scenario indicate that, at least to some extent, data collected in repeated exposures to a critical event resemble, in many important aspects, data obtained in an unexpected exposure to the same event. Thus, using repeated exposures in a careful manner, one can obtain much larger amounts of available data. In the particular case considered here, the steering behavior was largely conserved between exposures. With increased amounts of data, it becomes possible to carry out formal optimization of driver models (using, for example, the simulation environment presented here) without overfitting model parameters to noise in the data.
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| 7. |
- Benderius, Ola, 1985, et al.
(författare)
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Evidence for a fundamental property of steering
- 2014
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Ingår i: Proceedings of the Human Factors and Ergonomics Society. - : SAGE Publications. - 1071-1813 .- 2169-5067. - 9780945289456 ; 58:1, s. 884-888
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Konferensbidrag (refereegranskat)abstract
- In this paper, a general and fundamental property of steering is demonstrated: It is shown that steering corrections generally follow bell-shaped profiles of steering rate. The finding is strongly related to what is already known about reaching movements. Also, a strong linear relationship was found between the maximum steering wheel rate and the steering wheel deflection, something that indicates a constant movement time for the correction. Furthermore, by closer examination of those corrections that cannot be described by a single bell-shaped rate profile, it was found that they typically can be described using two or, in some cases three or four, overlapping profiles, something which relates to superposition of motor primitives.
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| 8. |
- Benderius, Ola, 1985
(författare)
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Modelling driver steering and neuromuscular behaviour
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis challenges the traditional view of treating steering behaviour as a tracking task, instead treating it as a reaching task. Here, reaching refers to a fundamental human behaviour with the the intriguing characteristic of having a linear relationship between maximum speed and distance, effectively making the movement time constant. Historically, by contrast, human steering behaviour has been modelled as tracking, since it was assumed that drivers follow the road by applying continuous error-minimising control. Early on, it was found that linear control could to some extent represent human steering behaviour, but with a consistent non-linear error referred to as the remnant. Using instead the framework of reaching, as in this thesis, one can better explain even the non-linear parts of steering behaviour.In the analysis of data collected within the work presented here, it was found that up to 70 % of all steering behaviour can be modelled as individual reaching movements or, in the case of driving, steering corrections. It was furthermore shown that, by allowing the superposition of two such corrections, nearly all steering behaviour can be modelled. In addition, apart from control aspects, the heuristics used by the driver have also been studied. By modelling driver behaviour in various traffic situations, it was found that the angle to an aim point was the best stimulus for a steering action. Based on reaching theory and the aim point heuristic, a new driver model was developed and tested in three different situations: A double lane change, a head-on collision scenario, and a lead vehicle braking scenario. In open-loop simulations, the model showed good results when compared with observed behaviour, for all three scenarios.Furthermore, special care was taken to avoid parameter redundancy. The model could, in fact, be defined by using only one tunable parameter, representing the stress level of the driver. From the simulations, it was found that larger values of the parameter were required in critical situations compared the values used in normal driving. The neuromuscular aspects of the driver were also studied. The new driver model mentioned above was refined to include such aspects, using the fact that a reaching movement can be explained by antagonistic muscle pairs. However, since driving also involves limb stabilisation, muscle co-contraction is also relevant. In a separate experiment, involving both adults and children, the reaction to a sudden and unexpected torque disturbance was studied. The observed behaviour could be attributed to both the stretch reflex and an automatic subconscious cognitive action. The thesis also discusses some applications where driver models of realistic steering behaviour can be useful, focusing on active safety systems and autonomous vehicles.
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| 9. |
- Benderius, Ola, 1985, et al.
(författare)
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The Best Rated Human-Machine Interface Design for Autonomous Vehicles in the 2016 Grand Cooperative Driving Challenge
- 2018
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Ingår i: IEEE transactions on intelligent transportation systems (Print). - 1524-9050 .- 1558-0016. ; 19:4, s. 1302-1307
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Tidskriftsartikel (refereegranskat)abstract
- This paper provides an in-depth description of the best rated human-machine interface that was presented during the 2016 Grand Cooperative Driving Challenge. It was demonstrated by the Chalmers Truck Team as the envisioned interface to their open source software framework OpenDLV, which is used to power Chalmers' fleet of self-driving vehicles. The design originates from the postulate that the vehicle is fully autonomous to handle even complex traffic scenarios. Thus, by including external and internal interfaces, and introducing a show, don't tell principle, it aims at fulfilling the needs of the vehicle occupants as well as other participants in the traffic environment. The design also attempts to comply with, and slightly extend, the current traffic rules and legislation for the purpose of being realistic for full-scale implementation.
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| 10. |
- Berger, Christian, 1980, et al.
(författare)
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Containerized development and microservices for self-driving vehicles: Experiences & best practices
- 2017
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Ingår i: Proceedings - 2017 IEEE International Conference on Software Architecture Workshops, ICSAW 2017: Side Track Proceedings. - 9781509047932 ; , s. 7-12
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Konferensbidrag (refereegranskat)abstract
- In this paper, experiences and best practices from using containerized software microservices for self-driving vehicles are shared. We applied the containerized software paradigm successfully to both the software development and deployment to turn our software architecture in the vehicles following the idea of microservices. Key enabling elements include onboarding of new developers, both researchers and students, traceable development and packaging, convenient and bare-bone deployment, and traceably archiving binary distributions of our quickly evolving software environment. In this paper, we share our experience from working one year with containerized development and deployment for our self-driving vehicles highlighting our reflections and application-specific shortcomings, our approach uses several components from the widely used Docker ecosystem, but the discussion in this paper generalizes these concepts. We conclude that the growingly complex automotive software systems in combination with their computational platforms should be rather understood as data centers on wheels to design both, (a) the software development and deployment processes, and (b) the software architecture in such a way to enable continuous integration, continuous deployment, and continuous experimentation.
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