| 1. |
- Akhmetov, Yerlan, et al.
(författare)
-
Predictive Driver Interpreter by using Inverse Model for Heavy Vehicles
- 2010
-
Ingår i: 13th International IEEE, Annual Conference on Intelligent Transportation Systems, Madeira Island, Portugal, September 19-22, 2010. ; , s. 174-179
-
Konferensbidrag (refereegranskat)abstract
- This paper evaluates predictive control and necessary time horizon for heavy vehicle's active safety functionality by using an inverse model as predictor. The predictive driver interpreter provides the anticipating signals for limiting the forward velocity which can guarantee a manoeuvre's safe realization without loss of control. It has been integrated in a control allocation structure. The controller has been tested for an open-loop avoidance manoeuvre which is given by a sine with dwell steering input. Simulations showed for the studied manoeuvre and truck configuration that the passive vehicle is stable up to amplitude of 105 deg of steering wheel angle. When no predictive horizon was applied in the control allocation, the amplitude could be increased to 150 deg. When a predictive horizon of 1.5 s was used the amplitude could be doubled and still be stable.
|
|
| 2. |
|
|
| 3. |
- Askerdal, Mikael, 1975, et al.
(författare)
-
Development of simplified air drag models including crosswinds for commercial heavy vehicle combinations
- 2024
-
Ingår i: Vehicle System Dynamics. - 1744-5159 .- 0042-3114. ; 62:5, s. 1085-1102
-
Tidskriftsartikel (refereegranskat)abstract
- Accurate range prediction requires good knowledge of the prevailing wind conditions and how they affect the energy consumption of the ego vehicle. A few different simplified vehicle air drag models that explicitly include the effect from crosswinds are presented and compared through some objective criteria. The models are developed from the normal air drag equation where the effect from wind is implicit and therefore often forgotten or neglected. The purpose is to find a low-complexity model complementing CFD models and wind tunnel tests, that can be used for range estimation and predictive energy management algorithms. To simplify online estimation, a requirement is that the air drag models only contain a few tuning parameters. The models are validated against CFD calculations for a few vehicle combinations and the best models show good accuracy for air attack angles up to at least 60 degrees. It is shown that the parameters of the simplified models can loosely be connected to some basic geometrical attributes of a vehicle combination so it should be possible to give at least a rough estimate of the parameters of a simplified model based on these geometrical attributes. This is useful for making a first estimate of the aerodynamic properties of a vehicle combination after major changes in the exterior, e.g. when adding a trailer. It also highlights that the size and the shape of the vehicle side may be mainly responsible for the high longitudinal air drag sensitivity to crosswinds for large vehicle combinations.
|
|
| 4. |
- Börve, Erik, 1998, et al.
(författare)
-
Interaction-Aware Trajectory Prediction and Planning in Dense Highway Traffic using Distributed Model Predictive Control
- 2023
-
Ingår i: Proceedings of the IEEE Conference on Decision and Control. - 2576-2370 .- 0743-1546. ; , s. 6124-6129
-
Konferensbidrag (refereegranskat)abstract
- In this paper we treat optimal trajectory planning for an autonomous vehicle (AV) operating in dense traffic, where vehicles closely interact with each other. To tackle this problem, we present a novel framework that couples trajectory prediction and planning in multi-agent environments, using distributed model predictive control. A demonstration of our framework is presented in simulation, employing a trajectory planner using non-linear model predictive control. We analyze performance and convergence of our framework, subject to different prediction errors. The results indicate that the obtained locally optimal solutions are improved, compared with decoupled prediction and planning.
|
|
| 5. |
- Dela, Nicolas, et al.
(författare)
-
A pilot evaluation of using large movement driving simulator experiments to study driver behaviour influence on active safety systems for commercial heavy vehicles
- 2009
-
Ingår i: Proceedings of the 21st International Symposium on Dynamics of Vehicles on Roads and Tracks (IAVSD'09), Stockholm, Sweden, August 17-21, 2009. - Linköping : ViP - Virtual prototyping and assessment by simulation.
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The evaluation of active safety functions like Electronic Stability Control (ESC) is of increasing importance, driven by legislation, to commercial heavy vehicle producers and to society as a whole to predict the potential benefits of the systems. Direct testing in real traffic with normal drivers of those functions are most often infeasible due to cost, repeatability and safety. This paper presents an attempt to explore the possibility of using large scale moving based driving simulators to evaluate functions like ESC. This is conducted through a simulator experiment where the subject drivers have been provoked in driving scenarios to ESC interventions. The experiment indicates the possibility of using driving simulators for evaluation purposes. This implies that studies of the benefits can be performed with higher accuracy regarding repeatability and evaluation testing of active safety functions can be made more cost efficient and without jeopardizing safety of involved driver and other road-users.
|
|
| 6. |
- Duijkeren, Niels van, et al.
(författare)
-
Real-Time NMPC for Semi-Automated Highway Driving of Long Heavy Vehicle Combinations
- 2015
-
Ingår i: 5th IFAC Conference on Nonlinear Model Predictive Control, NMPC'15, Seville, September 17-21, 2015.
-
Konferensbidrag (refereegranskat)abstract
- This work presents a Nonlinear Model Predictive Control (NMPC) approach to realtime trajectory generation for highway driving with long truck combinations. In order to consider all relevant information for the road and the surrounding traffic, we formulate a finite-horizonoptimal control problem (OCP) that incorporates a prediction model in spatial coordinates for the vehicle and the surrounding traffic. This allows road properties (such as curvature) to appear as known variables in the prediction horizon. The objective function of the resultingconstrained nonlinear least-squares problem provides a trade-off between tracking performance, driver comfort, and keeping a comfortable distance from fellow road users. The OCP is solved with a direct multiple shooting solution method implemented in a real-time iteration schemeusing ACADO code generation and compared with a feedback scheme that solves the entire nonlinear program in each time step with the interior point solver IPOPT. To illustrate the efficacy and the real-time implementability of the methodology, simulation results are presentedfor a high way merging scenario of a long heavy vehicle combination.
|
|
| 7. |
- Erdinc, Umur, 1992, et al.
(författare)
-
Modelling of Articulated Heavy Vehicles for Computation of Accurate Safe Operating Envelope for Yaw Stability
- 2023
-
Ingår i: Proceedings of the 17th International Symposium on Heavy Vehicle Transport & Technology (HVTT17).
-
Konferensbidrag (refereegranskat)abstract
- As articulated heavy vehicles switch to electric power, new ways of allocating wheel forces have emerged. To improve energy efficiency, it is increasingly common to use propulsion or regenerative braking on only one unit of the vehicle combination. This leads to yaw stability problems, mainly jackknifing if the towing unit has excessive wheel forces, or trailer swing if the trailing unit has excessive wheel forces. Hence, it becomes important to allocate the total force request into different units and actuators in a safe way. This paper formulates a nonlinear two-track model with a nonlinear tire model, combined slip, and roll degree of freedom. Thus, the presented model can accurately simulate brake-in-turn and propel-in-turn maneuvers at high lateral accelerations. And it can be used to study when the yaw instability occurs and understand if the maneuver is safe or not. One way to ensure safe control allocation is by implementing a safe operating envelope that restricts the allocation within predefined limits. This helps maintain control of the system and prevent any potential safety hazards. In this paper, a nonlinear two-track model is utilized to simulate a range of lateral accelerations and various combinations of braking forces between the tractor and semitrailer. Through this process, an envelope is obtained which is then compared to an envelope generated from a single-track model and validated against high-fidelity model-based envelopes. This rigorous process helps to ensure the accuracy and reliability of the two-track model.
|
|
| 8. |
- Erdinc, Umur, 1992, et al.
(författare)
-
Safe operating envelope based on a single-track model for yaw instability avoidance of articulated heavy vehicles
- 2023
-
Ingår i: Vehicle System Dynamics. - 1744-5159 .- 0042-3114. ; In Press
-
Tidskriftsartikel (refereegranskat)abstract
- The electrification of commercial vehicles has led to new wheel torque allocation options for propulsion and braking of articulated heavy vehicles. Each unit or axle can be individually braked or propelled whilst the other units or axles are excluded from such action. This may achieve the best energy efficiency. However, this can also lead to potential yaw stability problems such as jackknifing and trailer swing, especially under bad loading and weather conditions. This paper describes the above instabilities and introduces a nonlinear single-track model to study the vehicle dynamics of the tractor-semitrailer combination. The effects of different vehicle and environment parameters are analysed with this vehicle model. A safe operating envelope for limiting the wheel forces is obtained using this vehicle model. Since the vehicle model introduced in this paper is computationally effective, it can be run online in real vehicles, with an instantaneous safe operating envelope obtained for the momentary conditions. Thus, yaw instabilities such as jackknifing and trailer swing may be avoided.
|
|
| 9. |
- Erdinc, Umur, 1992, et al.
(författare)
-
Validation of high-fidelity simulation-based safe operating envelopes for articulated heavy vehicles using real test data
- 2024
-
Ingår i: Vehicle System Dynamics. - 1744-5159 .- 0042-3114. ; In Press
-
Tidskriftsartikel (refereegranskat)abstract
- The electrification of towing and trailing units creates new torque allocation alternatives among different units of articulated heavy vehicles. To increase the power and energy efficiency, control algorithms can request propulsion or regenerative braking from a single unit while keeping the other units unbraked or unpropelled. However, this may lead to safety problems, such as jackknifing or trailer swing. This paper uses a high-fidelity simulation tool to formulate safe operating envelopes for a tractor and semitrailer combination for braking-in-turn cases. The effects of different vehicle and environment parameters on the safe operating envelope are studied. The safe operating envelope obtained is then validated using real vehicle tests and can be used with any control algorithm to avoid requesting unsafe unit force combinations.
|
|
| 10. |
|
|
