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- Papaioannou, Georgios, et al.
(författare)
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Assessment of optimal passive suspensions regarding motion sickness mitigation in different road profiles and sitting conditions
- 2021
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Ingår i: 2021 IEEE International Intelligent Transportation Systems Conference (ITSC). - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 3896-3902
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Konferensbidrag (refereegranskat)abstract
- Automated vehicles (AVs) are expected to lead the evolution of mobility. Motion sickness, known as car sickness, is one of the main issues AVs will face, and could jeopardise their wide impact. However, a limited work has been done on how the optimisation of suspension dynamics could contribute. In this direction, this paper explores the mitigation of car sickness and the improvement of ride comfort through the optimisation of passive suspension systems. More specifically, a half car model, which represents a passenger vehicle from IPG/CarMaker, is used to optimise front suspension system for minimising comfort, but also maintaining vehicle handling while the vehicle is driving over two different road classes. The evaluation of comfort is conducted using the common standardised metric suggested by ISO-2631. After having obtained the optimum design solutions, the optimal solutions are simulated using IPG/CarMaker by assigning the road profiles on a 23 km long countryside road path. Then, vehicle accelerations are transferred to the occupant's head using appropriate models from the literature for both back-on and back-off sitting conditions. Afterwards, car sickness and ride comfort are further assessed to explore in detail how the tuning of the suspension systems through optimisation has minimised the first and enhanced the latter. For the assessment of car sickness, a three dimensional detailed biomechanical human model is used. The results imply that the pitch velocity seems more suitable, as a cost function for optimising the suspension systems with regards to motion sickness mitigation. Therefore, it should be considered either on its own or in combination with metric suggested by ISO-2631.
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| 2. |
- Schenk, Lydia, et al.
(författare)
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Musculoskeletal Driver Model for the Steering Feedback Controller
- 2021
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Ingår i: Vehicles. - : MDPI AG. - 2624-8921. ; 3:1, s. 111-126
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Tidskriftsartikel (refereegranskat)abstract
- This paper aims to find a mathematical justification for the non-linear steady state steering haptic response as a function of driver arm posture. Experiments show that different arm postures, that is, same hands location on the steering wheel but at different initial steering angles, result in a change in maximum driver arm stiffness. This implies the need for different steering torque response as a function of steering angle, which is under investigation. A quasi-static musculoskeletal driver model considering elbow and shoulder joints is developed for posture analysis. The torque acting in the shoulder joint is higher than in the elbow. The relationship between the joint torque and joint angle is linear in the shoulder, whereas the non-linearity occurs in the elbow joint. The simulation results qualitatively indicate a similar pattern as compared to the experimental muscle activity results. Due to increasing muscle non-linearity at high steering angles, the arm stiffness decreases and then the hypothesis suggests that the effective steering stiffness is intentionally reduced for a consistent on-center haptic response.
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