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2021 Vehicle Dynamics seminar
- 2021
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Editorial proceedings (other academic/artistic)abstract
- The seminar is held annually. The full title of this year's seminar was "2021 Vehicle Dynamics seminar -- for Future Mobility ...and not only Lateral".
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| 3. |
- Agebro, Markus, 1975-
(author)
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Driver Preferences of Steering Characteristics
- 2007
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Licentiate thesis (other academic/artistic)abstract
- The future of vehicle steering systems lies within by-wire technology. With by-wire technology mechanical or hydraulic systems are replaced by electronic systems. Removal of the steering column and possibly other linkage and gears yields vast potential of further improvement of performance, comfort and safety. Steer-by-wire technology also enables the manufacturer to tailor the steering feel to better suit the individual drivers’ need and preference. Since a driver gains critical information about the vehicle from feedback through the steering wheel, steering feel will play a very important part in consumer acceptance of steer-by-wire systems. It will also be possible to customize steering characteristics to the individual driver. This thesis presents a methodology for investigating steering characteristics through analysis of simulator experiments and to find the impact of specific steering characteristics on drivers of varying skill. There are many key aspects to consider when designing simulator experiments. A validated vehicle model is required. Evaluation criteria need to be well defined as well as concise and simple. The utilized scenario has to be able to capture the selected evaluation criteria. Recruitment of test subjects should represent the target population. How to utilize the available time in the simulator most effectively and how to analyze the results are also important. In this work three studies are performed. Paper A investigates how steering gear ratio and steering wheel effort of a passenger car affect preferences of high and low mileage drivers. Paper B is an extended study of Paper A, where the resolution is higher, speed dependence is investigated and performance of the drivers is also evaluated. In Paper C the impact of four important steering system characteristics on driver performance and preference is evaluated. The major conclusions drawn from this work are that variation of steering gear ratio has considerable impact on perceived steering feel and manoeuvrability as well as on driver performance. Variation in steering wheel effort affect perceived steering feel and stability, but no significant influence is detected in perceived manoeuvrability or driver performance. There are distinguishable differences in preferences of the investigated evaluation criteria between driver categories of varying skill. However, general trends of the preferences for the categories are fairly similar. Low skilled drivers prefer lower effort and higher ratio than high skilled drivers, especially at the highest investigated speed, 100 km/h. The developed methodology for performing simulator experiments to evaluate steering characteristics has proven satisfactory through findings of three different studies. This work also shows that there are several important steering characteristics that need to be considered when designing steering systems, particularly steering systems with by-wire applications and especially considering drivers of varying skill.
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Automated Comfortable Docking at Bus Stops
- 2021
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Editorial proceedings (other academic/artistic)abstract
- This proceedings presentation illustrates the optimization problem of autonomous bus parallel parking subjected to ride discomfort while navigating in a path with rectangular geometry constraints. During bus parking, passengers - especially standing- can experience discomfort due to acceleration and jerk components. In our project, a novel discomfort model was derived, utilizing acceleration and jerk data. This model was then implemented in an optimization problem to minimize discomfort. Simulation results and experiment results have been shown. The experiment was conducted using Volvo Autonomous Bus.
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- Baumann, Pia, et al.
(author)
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Outcome in a prospective phase II trial of medically inoperable stage I non-small-cell lung cancer patients treated with stereotactic body radiotherapy.
- 2009
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In: Journal of clinical oncology : official journal of the American Society of Clinical Oncology. - 1527-7755 .- 0732-183X. ; 27:20, s. 3290-6
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Journal article (peer-reviewed)abstract
- PURPOSE: The impact of stereotactic body radiotherapy (SBRT) on 3-year progression-free survival of medically inoperable patients with stage I non-small-cell lung cancer (NSCLC) was analyzed in a prospective phase II study. PATIENTS AND METHODS: Fifty-seven patients with T1NOMO (70%) and T2N0M0 (30%) were included between August 2003 and September 2005 at seven different centers in Sweden, Norway, and Denmark and observed up to 36 months. SBRT was delivered with 15 Gy times three at the 67% isodose of the planning target volume. RESULTS: Progression-free survival at 3 years was 52%. Overall- and cancer-specific survival at 1, 2, and 3 years was 86%, 65%, 60%, and 93%, 88%, 88%, respectively. There was no statistically significant difference in survival between patients with T1 or T2 tumors. At a median follow-up of 35 months (range, 4 to 47 months), 27 patients (47%) were deceased, seven as a result of lung cancer and 20 as a result of concurrent disease. Kaplan-Meier estimated local control at 3 years was 92%. Local relapse was observed in four patients (7%). Regional relapse was observed in three patients (5%). Nine patients (16%) developed distant metastases. The estimated risk of all failure (local, regional, or distant metastases) was increased in patients with T2 (41%) compared with those with T1 (18%) tumors (P = .027). CONCLUSION: With a 3-year local tumor control rate higher than 90% with limited toxicity, SBRT emerges as state-of-the-art treatment for medically inoperable stage I NSCLC and may even challenge surgery in operable instances.
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- Baumann, Pia, et al.
(author)
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Stereotactic body radiotherapy for medically inoperable patients with stage I non-small cell lung cancer - a first report of toxicity related to COPD/CVD in a non-randomized prospective phase II study.
- 2008
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In: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 88:3, s. 359-67
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Journal article (peer-reviewed)abstract
- BACKGROUND AND AIMS: In a retrospective study using stereotactic body radiotherapy (SBRT) in medically inoperable patients with stage I NSCLC we previously reported a local control rate of 88% utilizing a median dose of 15Gyx3. This report records the toxicity encountered in a prospective phase II trial, and its relation to coexisting chronic obstructive pulmonary disease (COPD) and cardio vascular disease (CVD). MATERIAL AND METHODS: Sixty patients were entered in the study between August 2003 and September 2005. Fifty-seven patients (T1 65%, T2 35%) with a median age of 75 years (59-87 years) were evaluable. The baseline mean FEV1% was 64% and median Karnofsky index was 80. A total dose of 45Gy was delivered in three fractions at the 67% isodose of the PTV. Clinical, pulmonary and radiological evaluations were made at 6 weeks, 3, 6, 9, 12, 18, and 36 months post-SBRT. Toxicity was graded according to CTC v2.0 and performance status was graded according to the Karnofsky scale. RESULTS: At a median follow-up of 23 months, 2 patients had relapsed locally. No grade 4 or 5 toxicity was reported. Grade 3 toxicity was seen in 12 patients (21%). There was no significant decline of FEV1% during follow-up. Low grade pneumonitis developed to the same extent in the CVD 3/17 (18%) and COPD 7/40 (18%) groups. The incidence of fibrosis was 9/17 (53%) and pleural effusions was 8/17 (47%) in the CVD group compared with 13/40 (33%) and 5/40 (13%) in the COPD group. CONCLUSION: SBRT for stage I NSCLC patients who are medically inoperable because of COPD and CVD results in a favourable local control rate with a low incidence of grade 3 and no grade 4 or 5 toxicity.
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- Bucca, Giuseppe, et al.
(author)
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Adoption of different pantographs' preloads to improve multiple collection and speed up existing lines
- 2012
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In: Vehicle System Dynamics. - : Informa UK Limited. - 0042-3114 .- 1744-5159. ; 50:SUPPL. 1, s. 403-418
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Journal article (peer-reviewed)abstract
- The current collection using more than one pantograph is needed in railway operation to provide power to non-electrically connected traction units and, in some cases, to reduce current density on the collector strips that heavily influences the wear on the contacting bodies. The multiple current collection may become a critical condition due to the mechanical disturbances produced on the trailing pantographs by the interaction between the first pantograph and the catenary. The present-day evolution of pantograph preload regulating systems, exploiting pressure-controlled servo-valves driven by electronic units, allows a diversification of the preloads of front and rear pantographs. In this work, a suitable solution to improve multiple pantograph collection quality is analysed by the use of a lower mean force on the leading pantograph aimed at reducing the oscillations of contact wire the trailing pantograph is subjected to. This would improve the current collection quality of the trailing pantograph, and could be pursued even admitting a slight worsening of front pantograph's performances.
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| 9. |
- Cocron, Peter, et al.
(author)
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Driver and vehicle behaviour to power train failures in electric vehicles : experimental results of field and simulator studies
- 2014
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Reports (other academic/artistic)abstract
- New electric power trains can be subject to different failures when compared to those arising in conventional vehicles. The objectives for active safety investigations within the EVERSAFE project were to address vehicle stability under these failure conditions and the driver response to relevant types of failures. Failure conditions that affect the vehicle stability are believed to be significantly different from today’s conventional internal combustion engine cars, and may potentially be a substantial safety problem if not treated in a correct manner. To study these effects, two examples of system failures and their consequences on the driver response and vehicle stability were investigated with the help of three studies.The first two studies investigated a failure of wheel hub motors (WHMs), an emerging technology among the future generation of electric vehicles (EV). The main benefits of a WHM are its controllability, high efficiency, high power density and low weight. However, the direct connection to the wheel comes along with the potential disadvantage in case a failure occurs in the system.The third study conducted within the active safety focus of the EVERSAFE project examined a failure of the regenerative braking (RB) system. The latter is a system designed to convert kinetic energy to chemical energy stored in the energy storage system (i.e. battery) while the vehicle decelerates.
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