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The growing market demand for highly automated and autonomous vehicles and the need to equip vehicles with ever higher standards of comfort, safety and performance requires knowledge of physical quantities that are often difficult or expensive to measure directly. The absence of direct sensors, the difficulty of implementation, and their cost have led researchers to identify alternative solutions that allow estimating the physical quantity of interest by aggregating other available information. The interaction forces between tire and road are among the most significant. Given that the dynamics of a vehicle are strongly linked to the forces exchanged between the tire and the road, their knowledge is fundamental in the development of control systems aimed at improving performance in terms of handling, road holding or comfort. This paper presents a new technique for the estimation of tire-road interaction forces based on the integration of models and measures.

This paper is part of the European OWHEEL project. It proposes a method to improve the comfort of a vehicle by adaptively controlling the Camber and Toe angles of a rear suspension. The purpose is achieved through two actuators for each wheel, one that allows to change the Camber angle and the other the Toe angle. The control action is dynamically determined based on the error between the reference angle and the actual angles. The reference angles are not fixed over time but dynamically vary during the maneuver. The references vary with the aim of maintaining a Camber angle close to zero and a Toe angle that follows the trajectory of the vehicle during the curve. This improves the contact of the tire with the road. This solution allows the control system to be used flexibly for the different types of maneuvers that the vehicle could perform. An experimentally validated sports vehicle has been used to carry out the simulations. The original rear suspension is a Trailing-arm suspension.

The activity described in this paper has been carried out in the framework of a funded project aimed at evaluating the feasibility of a controllable water pump based on an integrated magnetorheological fluid clutch. The advantages consist of an improvement of the overall vehicle performance and efficiency, in the possibility of disengaging the water pump when its action is not required, and in the control of the cooling fluid temperature. So, the design constraints have been defined with reference to the available space, required torque, and electrical power. After an iterative procedure, in which both mechanical design and magnetic field analyses have been considered, the most promising solution has been defined and a first physical prototype has been realized and tested. A preliminary experimental characterization of the developed prototype has been presented.

The paper describes the development of an innovative test rig for the evaluation of e-bikes in terms of energetic performances and control system. The test rig has been realized starting from a commercial cyclist training system and suitably modified. The test rig is able to reproduce an aforethought route or paths acquired during road tests. It is possible to measure the performance of the e-bike in terms of instantaneous power and speed, by the installed sensors and data acquisition system. The experimental test rig can simulate the resistant torque of a predetermined track and it aims to test and to optimize the control strategy available on the electronic control unit (ECU). An important feature of the system is represented by the possibility to adopt a hardware in the loop approach for the testing of the e-bike and of its control. Indeed, the whole control algorithm can be implemented on a suitable controller board able to execute real time processes.

A new controllable limited slip differential is proposed and tested in software environment. It is characterized by the employment of a magnetorheological fluid, which presents the property of changing its rheology thanks to an applied magnetic field. A vehicle model has been designed and employed for the synthesis of a sliding controller. The control is based on a double level scheme: the upper controller aims to generate the target locking torque, while the lower controller generates, as control action, the supply current for the controllable limited slip differential. The obtained results show the effectiveness of the device in terms of vehicle dynamics improvement. Indeed, the results reached by the vehicle in presence of the new differential confirm the improved performances for both steady and unsteady state manoeuvres.

This paper presents a semi-active differential, denoted by MRF LSD (Magneto-Rheological Fluid Limited Slip Differential) that allows to bias torque between the driving wheels. It is based on the Magneto-Rheological (MR) fluid employment, by which it is possible to change, in controlled manner, the internal friction torque and, consequently, the torque bias ratio. The device is an adaptive one and allows to obtain an asymmetric torque distribution in order to improve vehicle handling. The device modelling and the control algorithm, realized for this activity, are described. The illustrated results highlight the advantages that are attainable regarding directional behaviour, stability and traction for a front wheel drive (FWD) vehicle. A comparison with a traditional passive limited slip differential has been conducted.