Processor-in-the-loop architecture design and experimental validation for an autonomous racing vehicle

Self-driving vehicles have experienced an increase in research interest in the last decades. Nevertheless, fully autonomous vehicles are still far from being a common means of transport. This paper presents the design and experimental validation of a processor-in-the-loop (PIL) architecture for an autonomous sports car. The considered vehicle is an all-wheel drive full-electric single-seater prototype. The retained PIL architecture includes all the modules required for autonomous driving at system level: environment perception, trajectory planning, and control. Specifically, the perception pipeline exploits obstacle detection algorithms based on Artificial Intelligence (AI), and the trajectory planning is based on a modified Rapidly-exploring Random Tree (RRT) algorithm based on Dubins curves, while the vehicle is controlled via a Model Predictive Control (MPC) strategy. The considered PIL layout is implemented firstly using a low-cost card-sized computer for fast code verification purposes. Furthermore, the proposed PIL architecture is compared in terms of performance to an alternative PIL using high-performance real-time target computing machine. Both PIL architectures exploit User Datagram Protocol (UDP) protocol to properly communicate with a personal computer. The latter PIL architecture is validated in real-time using experimental data. Moreover, they are also validated with respect to the general autonomous pipeline that runs in parallel on the personal computer during numerical simulation

A Method for Battery Sizing in Parallel P4 Mild Hybrid Electric Vehicles

This article deals with a sensitivity analysis concerning the influence that the capacity of the battery in a parallel hybrid powertrain has on the vehicle's energy regeneration. The architecture under analysis is constituted by an internal combustion engine (ICE), which provides traction to the front axle's wheels, and an electric motor powering the rear wheels. The energy management system (EMS) is based on a simple torque split strategy that distributes the driver's required torque between the front and rear machines as a function of battery and electric motor functional limitations (state of charge, temperatures, and maximum admissible currents). Together with the selected driving cycles, the central role played by the battery size in the overall vehicle recoverable energy is evaluated, while the influence of the powertrain limitations is highlighted, accounting both for uncertain parameters (e.g., initial state of charge [SoC 0]) and for tunable parameters (e.g., maximum electric traction vehicle speed). Therefore, a method of sizing the battery of a P4 mild hybrid electric vehicle (HEV), which allows the maximization of the braking energy recovery, is developed

Serum thyroglobulin and 131I whole body scan after recombinant human TSH stimulation in the follow-up of low-risk patients with differentiated thyroid cancer

OBJECTIVE: The 'standard' postoperative follow-up of patients with differentiated thyroid cancer (DTC) has been based upon serum thyroglobulin (Tg) measurement and (131)I whole body scan ((131)I-WBS) after thyroid hormone (T(4)) treatment withdrawal. However, (131)I-WBS sensitivity has been reported to be low. Thyroid hormone withdrawal, often associated with hypothyroidism-related side effects, may now be replaced by recombinant human thyroid stimulating hormone (rhTSH). The aim of our study was to evaluate the diagnostic accuracy of (131)I-WBS and serum Tg measurement obtained after rhTSH stimulation and of neck ultrasonography in the first follow-up of DTC patients. DESIGN: Ninety-nine consecutive patients previously treated with total thyroidectomy and (131)I ablation, with no uptake outside the thyroid bed on the post-ablative (131)I-WBS (low-risk patients) were enrolled. METHODS: Measurement of serum Tg and (131)I-WBS after rhTSH stimulation, and ultrasound examination (US) of the neck. RESULTS: rhTSH-stimulated Tg was 1 ng/ml (Tg+) in 21 patients, including 6 patients with Tg levels >5 ng/ml. (131)I-WBS was negative for persistent or recurrent disease in all patients (i.e. sensitivity = 0%). US identified lymph-node metastases (confirmed at surgery) in 4/6 (67%) patients with stimulated Tg levels >5 ng/ml, in 2/15 (13%) with Tg>1<5 ng/ml, and in 2/78 (3%) who were Tg-negative. CONCLUSIONS: (i) diagnostic (131)I-WBS performed after rhTSH stimulation is useless in the first follow-up of DTC patients; (ii) US may identify lymph node metastases even in patients with low or undetectable serum Tg levels

Nostra esperienza sul trattamento chirurgico del microcarcinoma papillifero della tiroide (PTMC)

Il microcarcinoma papillifero della tiroide (PTMC) è un carcinoma papillifero (PTC) di diametro uguale o inferiore a 1 cm, in una percentuale variabile dal 15 al 20% dei casi bilaterale e multifocale. Descriviamo la nostra esperienza sul trattamento chirurgico di 217 pazienti affetti da tale patologia tra il 2005 ed il 2008. Il nostro algoritmo terapeutico per il microcarcinoma papillifero della tiroide prevede, di principio, la tiroidectomia con esplorazione del compartimento cervicale centrale e linfectomia ricorrenziale omolaterale, riservando la linfectomia del compartimento centrale solo ai casi di linfonodi patologici e quella laterocervicale mono- o bilaterale soltanto ai casi con linfonodi palpabili e/o ecograficamente sospetti e/o con FNAC positivo. La tiroidectomia totale, giustificata dall’alta frequenza di multifocalità della patologia, riduce l’incidenza delle recidive, determina una maggiore affidabilità della tireoglobulina quale marker di persistenza o recidiva di malattia ed un migliore utilizzo dello I131 a scopo diagnostico ed ablativo. Anche il razionale della dissezione linfonodale del compartimento centrale, laddove all’esplorazione si evidenziano linfonodi patologici, è senz’altro la riduzione della recidiva evitando così reinterventi, notoriamente gravati da più alta incidenza di ipoparatiroidismo e lesione ricorrenziale. La localizzazione del tumore non influenza l’incidenza di metastasi linfonodali che, invece, è direttamente proporzionale alla dimensione tumorale, così come descritto in letteratura (in percentuale variabile dal 55.7% per tumori fino a 5 mm al 73.7% da 5 a 10 mm) ed è, inoltre, strettamente correlata all’infiltrazione capsulare, alla multifocalità, oltre che, ovviamente, alla presenza di varianti istologiche a prognosi peggiore (soprattutto la sclerosante). Tutti i pazienti con microcarcinoma papillifero invadente la capsula o con estensione extracapsulare, quelli con variante sclerosante o tumore multifocale o metastatico ai linfonodi sono stati sottoposti a terapia radiometabolica e ormonoterapia a dosaggio soppressivo, in accordo con le linee guida nel gruppo multidisciplinare della nostra struttura

Design of Electromagnetic Dampers for Aero-Engine Applications

The vibration control of rotors for gas or steam turbines is usually performed using passive dampers when hydrodynamic bearings are not used. In layouts where the rotating parts are supported by rolling bearings the damping is usually provided by squeeze film dampers. Their passive nature and the variability of their performances with temperature and frequency represent the main disadvantages. Dampers with magneto-rheological and electro-rheological fluid allow solving only a part of the above mentioned drawbacks. Active magnetic bearings (AMB’s) are promising since they are very effective in controlling the vibration of the rotor and offering the possibility of monitoring the rotor’s behaviour using their displacement sensors. However they show serious drawbacks related to their stiffness. Electromagnetic dampers seem to be a valid alternative to visco-elastic, hydraulic dampers due to, among the others: the absence of all fatigue and tribology issues resulting from the absence of contact; the small sensitivity to the working environment; the wide possibility of tuning even during operation; the predictability of the behaviour; the smaller mass compared to AMB’s and the failsafe capability. The aim of the present paper is to describe a design methodology adopted to develop electromagnetic dampers to be installed in aero-engines. The procedure has been validated using a reduced scale laboratory test rig. The same approach has then been adopted to design the electromagnetic dampers for real civil aircraft engines. Results in terms of achievable vibration reductions, mass and overall dimensions are hence presented. A trade-off between the various proposed solutions has been carried out evaluating quantitative performance parameters together with qualitative aspects that this “more electric” technology implies

Low sleep quality and daytime sleepiness in obese patients without obstructive sleep apnoea syndrome

OBJECTIVES: To evaluate sleep quality, sleep-related symptoms, and degree of excessive daytime sleepiness (EDS) in severe obesity, independently of obstructive sleep apnoea syndrome (OSAS). DESIGN: A cross-sectional study. SETTING: Primary-care setting. SUBJECTS, MAIN OUTCOME MEASURES: Anthropometric parameters, respiratory function data and sleep related symptoms were evaluated in 78 severely obese patients (aged 16-75 years) without OSAS and in 40 healthy sex- and age-matched normal weight subjects, who underwent a full-night polysomnography. RESULTS: Obese patients and control subjects had similar sleep latency and rapid eye movement (REM) latency, but they showed lower percentage of REM (P < 0.01) and sleep efficiency (P < 0.05) than controls. All sleep-related symptoms (observed or reported apnoea, awakenings, choking and unrefreshing sleep) were significantly more frequent in obese patients than in control subjects. Loud snoring was present in 46.7% of the obese patients and in 8.1% of the control individuals (P < 0.01). Excess daytime sleepiness was reported by 34.7% of the obese patients and by 2.7% of the normal weight subjects (P < 0.01). The Epworth Sleepiness Scale (ESS) was higher in the obese group than in the control group (P < 0.01), whereas arousals were not different between the two groups. CONCLUSIONS: This study clearly shows that severe obesity, even in the absence of OSAS, is associated with sleep-related disorders and EDS. All these alterations may be partly responsible for a lower quality of life, a higher prevalence of medical complications, an increased risk of occupational injury, and both social and family problems characterizing obese patients, independently of the presence of OSAS