Can experienced riders benefit from an autonomous emergency braking system?

Powered two wheelers (PTWs) are becoming increasingly popular in Europe but the risk of rider injury in a traffic crash far exceeds that for car occupants. The European Powered Two wheeler Integrated Safety project (PISa), identified autonomous emergency braking (MAEB) as a priority area for reducing the injury consequences of PTW crashes. This study assessed the potential effectiveness of the PISa MAEB system, specifically in relation to its potential benefit for experienced riders . A sample of fifty-eight in-depth PTW crashes representing typical European crash scenarios were examined, of which half involved a rider with MAIS 2+ injury. An expert team analysed the data to determine the extent to which the MAEB would have affected the crash. In 39 cases (67% of the sample) the MAEB showed high potential to mitigate the crash outcome. Results indicated that, not only does the MAEB have potential to help novice riders but could also considerably improve safety for more experienced riders. The results shown here could encourage further development and acceptance of such systems

PISa – powered two wheeler integrated safety: development, implementation and testing of PTW integrated safety systems

The Powered two wheeler Integrated Safety (PISa) project, funded by the European Commission within the 6th Framework, aimed at identifying, developing and testing new technologies to provide integrated safety systems (ISS) for a range of powered two wheelers (PTWs) to improve primary safety and link to secondary safety systems. From the analysis of representative crashes involving motorcycles and mopeds, a list of safety systems was prioritised in terms of their contribution to crash avoidance or injury severity reduction. These systems were integrated onto two different types of PTW: a large scooter and a light motorcycle. Experimental tests with the demonstration vehicles showed the potential benefits of the PISa systems compared to unequipped PTWs. Further system development is required before testing the demonstration vehicles with non-professional riders

Evaluation of an autonomous braking system in real-world PTW crashes

Objectives: Powered 2-wheelers (PTWs) are becoming increasingly popular in Europe. They have the ability to get around traffic queues, thus lowering fuel consumption and increasing mobility. The risk of rider injury in a traffic crash is however much higher than that associated with car users. The European project, Powered Two Wheeler Integrated Safety (PISa), identified an autonomous braking system (AB) as a priority to reduce the injury consequences of a PTW crash. The aim of this study was to assess the potential effectiveness of the AB system developed in PISa, taking into account the specific system characteristics that emerged during the design, development and testing phases. Methods: Fifty-eight PTW cases representing European crash configurations were examined, in which 43 percent of riders sustained a Maximum Abbreviated Injury Scale (MAIS) 2+ injury. Two of the most common crash types were a PTW impacting a stationary object (car following scenario) 16% and an object pulling across the PTW path (crossing scenario) 54%. An expert team analysed the in-depth material of the sample crashes and determined a posteriori to what extent the AB would have affected the crash. For those cases where the AB was evaluated as applicable, a further quantitative evaluation of the benefits was conducted by considering a set of different possible rider reactions in addition to that exhibited in the actual crash. Results: In 67 percent of cases, the application of AB could have mitigated the crash outcome. Analysis of those real crash cases showed the potential for an expert rider to avoid the collision. An early reaction of the rider, associated with a correct application of the brakes would have avoided 18 of the 37 car following/crossing scenarios. Conversely, according to the analysis, an expert rider would not have been able to avoid 19 of the 37 cases. In 14 of those 19 cases, the AB would have contributed to mitigating the crash outcome. Conclusions: This study demonstrated significant potential for application of the autonomous braking system in car following and crossing scenarios. In addition, the theoretical benefit curves for the AB globally, were able to provide good quantitative indications of its benefits in real cases where the AB was considered applicable. Further analysis with larger databases is suggested in order to confirm the magnitude of benefits in the PTW crash population. Supplemental materials are available for this article. Go to the publisher’s online edition of Traffic Injury Prevention to view the supplemental file

Assessment of the effect of motorcycle autonomous emergency braking (MAEB) based on real-world crashes

Objective: Vehicles are increasingly being equipped with Autonomous Emergency Braking (AEB) and literature highlights the utility to fit a similar active safety system in Powered Two-Wheelers (PTWs). This research attempts to analyze the efficacy of PTW Autonomous Emergency Braking (MAEB) when functioning solely, and in the case where both the PTW and Opponent Vehicle (OV) have AEB installed. Methods: 23 crashes involving motorcyclists that occurred in metropolitan areas of Italy between 2009 and 2017 were selected. The “In-depth Study of road Accidents in FlorencE (InSAFE)” provides data for the study. Each crash was reconstructed in PC-Crash 12.1 software. The obtained simulation of the crash dynamics was then used to create the dataset of cases fitted with AEB and MAEB systems. A custom MAEB system was implemented with specifications based on literature. Results: The majority of crashes occurred on urban roads, at intersections, on dry asphalt, with clear visibility, and in daylight. The passenger vehicle was the most frequent opponent vehicle (70%). Almost half the sample involved the PTW rider traveling beyond the speed limit permitted on urban roads. MAEB was found to be applicable in 19 out of 23 real-world crashes allowing the avoidance of two crashes with the progressive triggering criteria (Time to Collision (TTC) − 1.0 s) and one crash in the case where both the PTW and OV have AEB installed with more conservative setups. MAEB simulations show important trends in the reduction of the PTW impact speed (ISR) from the conservative (TTC-0.6s) to standard (TTC-0.8s) to progressive (TTC-1.0s) triggering criteria. The mean impact speed reduction (ISR) becomes 8.6 km/h, 13.8 km/h, 19.1 km/h, respectively. Conclusions: The results suggested that MAEB may be extremely effective in the PTW impact speed reduction and that an earlier MAEB intervention is beneficial in achieving higher reductions in the PTW impact speed. Further, the effect of opponent vehicles also possessing AEB was studied, and it was found that this increased the likelihood of crash avoidance and greater reduction in crash severity in unavoidable circumstances.</p

Effect of Ring Size on the Tautomerization and Ionization Reaction of Cyclic 2-Nitroalkanones: An Experimental and Theoretical Study

The keto–enol tautomerism of some cyclic 2-nitroalkanones was studied in cyclohexane. Keto–enol equilibrium constants, <i>K</i>_T, at 25 °C were obtained from ¹H NMR spectra. The relative enol content for the investigated ketones as a function of ring size decreases in the order 6 > 7 > 11 > 12 > 15. This trend apparently is different from that observed in water. Density functional theory (DFT) calculations have been performed to rationalize the effects of ring size and of the solvent on tautomerism. The acidity constants, <i>K</i>_a^KH, for the different keto tautomers were measured spectrophotometrically at 25 °C in buffered aqueous solutions. No simple correlations between <i>K</i>_a^KH and ring size was observed, and this is in agreement with a DFT analysis performed on the same compounds

Synthesis of a Double-Spanned Resorc[4]arene via Ring-Closing Metathesis and Calculation of Aggregation Propensity

Ring-closing metathesis (RCM) catalyzed by a second-generation Grubbs catalyst has been used to synthesize resorc[4]­arenes <b>2b</b>–<b>5b</b> starting from undecenyl resorc[4]­arene <b>1b</b> fixed in the cone conformation. X-ray diffraction analysis of the major metathesis product, <b>3b</b> (50% yield), revealed a cavity-shaped architecture resembling a basket, endowed with a large intramolecular space (∼10 Å) and a strong propensity to self-assemble as a supramolecular trio of heterochiral dimers. This prompted us to investigate the aggregation propensity of basket <b>3b</b> in THF/water solution by UV–visible spectroscopy. The cavitation Gibbs free-energy change (ΔΔ<i>G</i>_cav = 4.78 kcal mol^–1) associated with the self-assembly of macrocycle <b>3b</b> was calculated as a measure of the solvophobic interactions involved in the process

Reaction of Nitrosonium Cation with Resorc[4]arenes Activated by Supramolecular Control: Covalent Bond Formation

Resorc­[4]­arenes <b>1</b> and <b>2</b>, which previously proved to entrap NO⁺ cation within their cavities under conditions of host-to-guest excess, were treated with a 10-fold excess of NOBF₄ salt in chloroform. Kinetic and spectral UV–visible analyses revealed the formation of isomeric 1:2 complexes as a direct evolution of the previously observed event. Accordingly, three-body <b>1</b>–(NO⁺)₂ and <b>2</b>–(NO⁺)₂ adducts were built by MM and fully optimized by DFT calculations at the B3LYP/6-31G­(d) level of theory. Notably, covalent nitration products <b>4</b>,<b> 5</b> and <b>6</b>,<b> 7</b> were obtained by reaction of NOBF₄ salt with host <b>1</b> and <b>2</b>, respectively, involving macrocycle ring-opening and insertion of a nitro group in one of the four aromatic rings. In particular, compounds <b>4</b> and <b>6</b>, both containing a trans-double bond in the place of the methine bridge, were oxidized to aldehydes <b>5</b> and <b>7</b>, respectively, after addition of water to the reaction mixture. Calculation of the charge and frontier orbitals of the aromatic donor (HOMO) and the NO⁺ acceptor (LUMO) clearly suggests an ipso electrophilic attack by a first NO⁺ unit on the resorcinol ring, mediated by the second NO⁺ unit

2-(Alkyl/Aryl)Amino-6-Benzylpyrimidin-4(3<i>H</i>)-ones as Inhibitors of Wild-Type and Mutant HIV-1: Enantioselectivity Studies

The single enantiomers of two pyrimidine-based HIV-1 non-nucleoside reverse transcriptase inhibitors, <b>1</b> (MC1501) and <b>2</b> (MC2082), were tested in both cellular and enzyme assays. In general, the <i>R</i> forms were more potent than their <i>S</i> counterparts and racemates and (<i>R</i>)-<b>2</b> was more efficient than (<i>R</i>)-<b>1</b> and the reference compounds, with some exceptions. Interestingly, (<i>R</i>)-<b>2</b> displayed a faster binding to K103N RT with respect to WT RT, while (<i>R</i>)-<b>1</b> showed the opposite behavior