| 1. |
- Ganesan, Anand, 1985, et al.
(författare)
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Real-Time Mixed-Integer Energy Management Strategy for Multi-Motor Electric Vehicles
- 2023
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Ingår i: 2023 IEEE Transportation Electrification Conference and Expo, ITEC 2023.
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Konferensbidrag (refereegranskat)abstract
- This paper11This work was supported by the Sweden's Innovation Agency (Vinnova) under Grant 2017-05506. presents a real-time capable energy management strategy for multi-motor electric vehicles, based on mixed-integer model predictive control (MI-MPC). In this strategy, torque allocation and clutch on-off are co-optimized to minimize both the energy consumption and the frequent changes in clutch engagement status. To be able to solve the mixed-integer (MI) problem in real time, we propose a bi-level programming approach in which the torque allocation subproblem is solved at the inner level using an explicit closed-form analytical solution, while the integer decisions are optimized at the outer level using implicit dynamic programming (i-DP). The simulation results show that the proposed strategy can achieve up to 11 % energy savings, depending on the load demand in a driving mission, compared to a rule-based controller typically used in production vehicles. In addition, the proposed approach is guaranteed to find the global optimum for the MI problem in each MPC update. With a mean time to solution of around 4.6 ms, the proposed strategy shows promising real-time capabilities for online implementation in multi -motor electric vehicles.
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| 2. |
- Al Mouatamid, Faouzi, 1989, et al.
(författare)
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Towards Evaluation of Post Impact Braking Function in Driving Simulator
- 2013
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Ingår i: Proceedings of the IEEE International Conference on Systems, Man, and Cybernetics, Manchester, United Kingdom, Oct 13-16, 2013.. - 9780769551548 ; , s. 4549-4554
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Konferensbidrag (refereegranskat)abstract
- This paper presents a method to evaluate the vehicle Post Impact Braking function in driving simulator environment. This function is designed to apply automatic braking after an initial impact on the vehicle body. Four representative impact scenarios and three typical driving styles are investigated, assuming Anti-lock Brake System (ABS) is either functioned or malfunctioned. The performance of PIB is quantified by comparing certain post impact states when the function is enabled and disabled. The results show that PIB helps the drivers to lower the risk and severity of secondary collisions with respect to reduced displacements and road leaving speed; while it leads to higher risk for possible side collisions due to increased yaw angle; these influences seem to be more considerable when no ABS is available. Passive drivers are found to gain more benefits than Alert-Skilled drivers that it indicates full-braking can degrade the vehicle steerability and thus the lateral and yaw responses to some extent. © 2013 IEEE.
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| 3. |
- Arikere, Adithya, 1987, et al.
(författare)
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Experimental Verification of Evasive Manoeuvre Assist Controller for Collision Mitigation with Oncoming Vehicles
- 2018
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Ingår i: Proceedings of the 14th International Symposium on Advanced Vehicle Control (AVEC’ 18), Beijing, China.
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Konferensbidrag (refereegranskat)abstract
- An evasive manoeuvre assist controller to mitigate the risk of collision with oncoming vehicles while performing evasive manoeuvres has previously been formulated and tested in simulation. In this work, a real-time application of this controller is implemented and used in experiments with a Volvo XC90 hybrid test vehicle. For comparison, manoeuvres are also carried out without the controller but with the driver adopting different speed control strategies. Analysis of the results show that the controller can consistently mitigate collision risk with the oncoming vehicle and while driver control of speed can perform better, it is far less robust and is heavily dependant on the driver skill and performance.
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| 4. |
- Arikere, Adithya, 1987, et al.
(författare)
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Integrated evasive manoeuvre assist for collision mitigation with oncoming vehicles
- 2018
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Ingår i: Vehicle System Dynamics. - : Informa UK Limited. - 1744-5159 .- 0042-3114. ; 56:10, s. 1577-1603
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Tidskriftsartikel (refereegranskat)abstract
- Development and deployment of steering based collision avoidance systems are made difficult due to the complexity of dealing with oncoming vehicles during the evasive manoeuvre. A method to mitigate the collision risk with oncoming vehicles during such manoeuvres is presented in this work. A point mass analysis of such a scenario is first done to determine the importance of speed for mitigating the collision risk with the oncoming vehicle. A characteristic parameter was identified, which correlates well with the need to increase or decrease speed, in order to reduce the collision risk. This finding was then verified in experiments using a Volvo XC90 test vehicle. A closed-loop longitudinal acceleration controller for collision mitigation with oncoming vehicles is then presented. The longitudinal control is combined with yaw stability control using control allocation to form an integrated controller. Simulations in CarMaker using a validated XC90 vehicle model and the proposed controller showed consistent reductions in the collision risk with the oncoming vehicle.
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| 5. |
- Arikere, Adithya, 1987, et al.
(författare)
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Optimal motion control for collision avoidance at Left Turn Across Path/Opposite Direction intersection scenarios using electric propulsion
- 2019
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Ingår i: Vehicle System Dynamics. - : Informa UK Limited. - 1744-5159 .- 0042-3114. ; 57:5, s. 637-664
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Tidskriftsartikel (refereegranskat)abstract
- Collision avoidance at intersections involving a host vehicle turning left across the path of an oncoming vehicle (Left Turn Across Path/Opposite Direction or LTAP/OD) have been studied in the past, but mostly using simplified interventions and rarely considering the possibility of crossing the intersection ahead of a bullet vehicle. Such a scenario where the driver preference is to avoid a collision by crossing the intersection ahead of a bullet vehicle is considered in this work. The optimal vehicle motion for collision avoidance in this scenario is determined analytically using a particle model within an optimal control framework. The optimal manoeuvres are then verified through numerical optimisations using a two-track vehicle model, where it was seen that the wheel forces followed the analytical global force angle result independently of the other wheels. A Modified Hamiltonian Algorithm (MHA) controller for collision avoidance that uses the analytical optimal control solution is then implemented and tested in CarMaker simulations using a validated Volvo XC90 vehicle model. Simulation results showed that collision risk can be significantly reduced in this scenario using the proposed controller, and that more benefit can be expected in scenarios that require larger speed changes.
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| 6. |
- Gordon, Timothy James, 1953, et al.
(författare)
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Robust Implementation of Automated Collision Avoidance Using an Updating Particle Reference
- 2018
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In recent work, an autonomous collision avoidance system was described, targeting speed and path changes based on optimal control theory applied to a friction-limited particle. This avoids artificial separation of the control problem into path-planning and path following, fully integrates speed control and stability criteria with the lateral motion control, and provides a modular framework for motion control at the limits of friction. The present paper extends the previous work by providing an updating reference aimed at improving the robustness and real-world applicability of the controller. The controller is tested and evaluated under conditions of uncertain geometry and surface friction, using a high-fidelity simulation model as well as physical testing on the track.
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| 7. |
- Harinath, Preetham, et al.
(författare)
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An Adapted Evasive Manoeuvre Assist Function for Over-Reactive and Under-Reactive Drivers
- 2020
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Ingår i: Lecture Notes in Mechanical Engineering. - Cham : Springer International Publishing. - 2195-4356 .- 2195-4364. - 9783030380762 ; , s. 1017-1026
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Konferensbidrag (refereegranskat)abstract
- In the present paper, an Evasive Manoeuvre Assist (EMA) function is designed to adapt to dierent types of drivers, by an opti- mised steering torque overlay. The existing EMA function amplies the driver steering inputs using a feed-forward controller which might not necessarily help an over-reactive driver. There exists a need for an EMA which adapts to dierent drivers as it minimises the risk of collision and gives the driver an experience of good control. The focus of this pa- per is to identify and dene a proper steering sequence reference model for closed-loop feedback control design. A simple single-point preview model is designed rst to calculate the reference steering angle. A few test scenarios are set-up using the IPG CarMaker simulation tool. The reference model is then calibrated with respect to the amplitude and fre- quency of the steering sequence by simulations to obtain the optimal steering prole. A feedback controller is then designed using this refer- ence model. The robustness of the function is veried in real-time, using a Volvo rapid-prototype test vehicle.
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| 8. |
- Jacobson, Bengt J H, 1962, et al.
(författare)
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Potential effectiveness of a stability control system for passenger cars after an initial side impact
- 2014
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Ingår i: FISITA 2014 World Automotive Congress - Proceedings.
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Konferensbidrag (refereegranskat)abstract
- Vehicle multiple-event accidents constitute 1/4-1/3 of all severe accidents. The present paper studies the control of the vehicle’s abnormal motion after being hit by another vehicle. The potential effectiveness of such a stability control system is estimated through accident data analysis and vehicle dynamics simulation. Only side impacts were simulated, but engineering judgments were made to project the effectiveness potential prediction on the total traffic work. Assuming ESC-like control (closed loop control on yaw rate, using wheel brakes) it is found that the function has potential to mitigate accident for up to 10-9 cars per driven km, or up to 0.1% of the cars in the accident database. While assuming Post Impact Stability Control by steering (closed loop control on yaw angle and path deviation, using steering), the corresponding figures are approximately ten times higher.
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| 9. |
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| 10. |
- Jacobson, Bengt J H, 1962, et al.
(författare)
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Vehicle tyre to road friction value estimation arrangement
- 2018
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Patent (övrigt vetenskapligt/konstnärligt)abstract
- A vehicle tyre to road friction value estimation arrangement (1) is provided comprising a vehicle impact detecting unit (3), a vehicle wheel axle lateral acceleration estimation unit (5.1, 5.2, 5.3, 5.4), and a processing unit (7). The vehicle impact detecting unit (3) is arranged to detect occurrence of an impact. The vehicle wheel axle lateral acceleration estimation unit (5.1, 5.2, 5.3, 5.4) is arranged to, upon a detected occurrence of an impact, estimate or measure a lateral acceleration of at least one vehicle wheel axle (13.1, 13.2) of the host vehicle (9). The processing unit (7) is arranged to determine an occurrence of a shift in direction of the lateral acceleration, and obtain a subsequent peak lateral acceleration estimate and to calculate an estimate of a host vehicle tyre to road friction value based on the thus obtained peak lateral acceleration estimate. The present invention also relates to a post impact vehicle control system (2), a vehicle (9) comprising a post impact vehicle control system (2) and a method (100) of estimating a vehicle tyre to road friction value. The present invention relates to a vehicle tyre to road friction value estimation arrangement. The present invention also relates to post impact vehicle control system comprising a vehicle tyre to road friction value estimation arrangement and a vehicle comprising a post impact vehicle control system and a method of estimating a vehicle tyre to road friction value. https://encrypted.google.com/patents/EP2883771A1?cl=un
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