Soft handling is nowadays evaluated based on subjective tests, where experienced drivers judge the behaviour of the tyre. The aim of this work is analyzing the soft handling maneuvers and trying to correlate the driver's sensations with some KPIs coming from the analysis of the acquired data. In order to get a more objective evaluation of soft handling, a study has been made by simulating different maneuvers with a single track model, to see the effect on the vehicle's dynamic. In particular, step input (for evaluating the response), sine test (to investigate the behavior at low lateral accelerations) and weave test (to evaluate the torque linearity) have been considered. The model has been used in order to make a preliminary evaluation of some KPIs, thanks to some numerical models which allowed to analyze the effect of cornering stiffness and relaxation length. Then, an outdoor test has been performed: by analyzing the acquired data, some consistent KPIs have been introduced. This work will contribute to understand how to deal with soft handling maneuvers, in order to have an objective feedback together with the driver's evaluation. The aim is to introduce some objective indexes helping to evaluate vehicle-tyre behaviour during subjective tests. One of the biggest problem of these kind of tests is related to the repeatability of the maneuvers: the given inputs and so the involved accelerations are quite small, so they are difficult to be repeated. For this reason, the proposed KPIs related for example to the steering sensation around zero or to the response gain have been implemented trying to avoid the dependence on the input. As future developments, new maneuvers and new KPIs could be investigated, considering also a frequency analysis of the results.
Le manovre di soft handling vengono oggi valutate sulla base di test soggettivi. L’obiettivo di questa tesi è analizzare queste manovre e cercare di correlare le sensazioni del pilota con qualche KPIs analizzando i dati acquisiti. Per rendere l'analisi più oggettiva, è stato condotto uno studio preliminare simulando su un modello monotraccia le manovre per vederne l’effetto sulla dinamica del veicolo. In particolare, le manovre di step input (per valutare la risposta), sine test ( per studiare il comportamento a basse accelerazion laterali) e weave test (per valutare la linearità della coppia) sono stati considerati. Il modello è stato utilizzato per fare delle analisi preliminari su alcuni KPI, grazie a modelli numerici che hanno permesso di comprendere l'effetto della rigidezza di deriva e della lunghezza di rilassamento. Successivamente, sono stati effettuati dei test su pista: analizzando i dati acquisiti, sono stati introdotti KPIs coerenti. Questo lavoro aiuterà a capire come approciare le manovre di soft handling, per poi avere un riscontro oggettivo da confrontare con le valutazioni dei piloti. Lo scopo è introdurre alcuni indici oggettivi che aiutino a valutare il comportamento veicolo-pneumatico durante i test soggettivi. Uno dei più grandi problemi di questi test è la ripetibilità delle manovre: Gli input dati, e quindi l'accelerazione laterale risultante, sono piuttosto piccoli, quindi difficilmente replicabili. Per questa ragione, i KPIs proposti relativi per esempio alla sensazione di sterzo intorno a zero o alla risposta sono stati implementati cercando di evitare la dipendenza dall’input. Come sviluppi futuri, nuove manovre e nuovi KPIs possono essere studiati, considerando anche un'analisi nel campo delle frequenze.
KPIs study for soft-handling maneuvers in outdoor test: correlation between driver's evaluations and numerical data
Corradini, Luca
2021/2022
Abstract
Soft handling is nowadays evaluated based on subjective tests, where experienced drivers judge the behaviour of the tyre. The aim of this work is analyzing the soft handling maneuvers and trying to correlate the driver's sensations with some KPIs coming from the analysis of the acquired data. In order to get a more objective evaluation of soft handling, a study has been made by simulating different maneuvers with a single track model, to see the effect on the vehicle's dynamic. In particular, step input (for evaluating the response), sine test (to investigate the behavior at low lateral accelerations) and weave test (to evaluate the torque linearity) have been considered. The model has been used in order to make a preliminary evaluation of some KPIs, thanks to some numerical models which allowed to analyze the effect of cornering stiffness and relaxation length. Then, an outdoor test has been performed: by analyzing the acquired data, some consistent KPIs have been introduced. This work will contribute to understand how to deal with soft handling maneuvers, in order to have an objective feedback together with the driver's evaluation. The aim is to introduce some objective indexes helping to evaluate vehicle-tyre behaviour during subjective tests. One of the biggest problem of these kind of tests is related to the repeatability of the maneuvers: the given inputs and so the involved accelerations are quite small, so they are difficult to be repeated. For this reason, the proposed KPIs related for example to the steering sensation around zero or to the response gain have been implemented trying to avoid the dependence on the input. As future developments, new maneuvers and new KPIs could be investigated, considering also a frequency analysis of the results.| File | Dimensione | Formato | |
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https://hdl.handle.net/10589/198490