18 IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY, VOL. 19, NO. 1, JANUARY 2011 Design and Validation of a Gain-Scheduled Controller for the Electronic Throttle Body in Ride-by-Wire Racing Motorcycles Matteo Corno, Mara Tanelli, Member, IEEE, Sergio M. Savaresi, Member, IEEE, and Luca Fabbri Abstract—This paper presents the analysis, design and vali- dation of a gain-scheduled controller for an electronic throttle body (ETB) designed for ride-by-wire applications in racing motorcycles. Specifically, the open-loop dynamics of the system are studied in detail discussing the effects of friction based on appropriate experiments. Further, a linear time invariant nominal model of the system to be controlled is experimentally identified via a frequency-domain black box approach, together with the un- certainty bounds on the model parameters. Based on these results a model-based gain-scheduled proportional-integral-differential (PID) controller for throttle position tracking is proposed. The closed-loop stability of the resulting linear parametrically varying (LPV) system is proved by checking the feasibility of an appro- priate linear matrix inequality (LMI) problem, and the state space representation of the closed-loop LPV system is experimentally validated. Finally, the performance of the controlled system is compared to the intrinsic limit of the actuator and tested under realistic use, namely both on a test-bench employing as set-point the throttle position recorded during test-track experiments and on an instrumented motorcycle. Index Terms—Electronic throttle body (ETB), gain-scheduled control, linear parameter varying (LPV) model validation, motor- cycle dynamics. I. INTRODUCTION AND MOTIVATION T HE electronic throttle body (ETB) is a mechatronic actu- ator devoted to the regulation of the air inflow at the en- gine intake manifold. According to the drive-by-wire paradigm, an accurate control of the ETB dynamics enables a correct and optimized management of the air mass flow rate, which can be managed independently of the rider’s request. The availability of a properly controlled ETB provides several advantages. First Manuscript received May 08, 2009; revised November 26, 2009; accepted July 14, 2010. Manuscript received in final form August 08, 2010. Date of pub- lication September 07, 2010; date of current version December 22, 2010. Rec- ommended by Associate Editor C. Novara. This work was supported in part by MIUR Project “New methods for Identification and Adaptive Control for Indus- trial Systems” and by Piaggio & C. S.p.A., Aprilia Brand. M. Corno is with the Delft Center for Systems and Control (DCSC), Delft University of Technology, 2628 CD Delft, The Netherlands (e-mail: m.corno@tudelft.nl). M. Tanelli and S.M. Savaresi are with the Dipartimento di Elettronica e In- formazione, Politecnico di Milano, 20133 Milano, Italy (e-mail: tanelli@elet. polimi.it; savaresi@elet.polimi.it). L. Fabbri is with Piaggio & C. S.p.A., Aprilia Brand, 30033 Noale, Venice, Italy. Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TCST.2010.2066565 of all, it can be employed to achieve a regularization of the dy- namic relationship between the gas command and the driving torque transmitted to the ground during acceleration maneuvers, thereby offering a smoother vehicle dynamic behavior which can significantly enhance the vehicle handling and driveability. Further, the ETB is also employed as an engine protection mech- anism. It ensures that the engine operates within a controlled range, for example limiting the engine speed and regulating the idle speed. From a more advanced vehicle dynamics control perspective, moreover, the ETB offers a way to differently shape the air flow rate behavior in the face of a given acceleration command, thus providing a means to customize the vehicle dynamic response to the drivers’ gas request. This feature also allows vehicle manu- facturers to personalize the vehicle driving feeling by conferring it either a performance-oriented or a comfort-oriented dynamic behavior, which would be in principle dictated by its mechan- ical layout, simply via a different tuning of the ETB electronic control system. Finally, of course, an effective ETB control system is a mandatory building block for the design of traction control system both for four- and two-wheeled vehicles, e.g., [1]–[3]. Note that, mechanically, a throttle is a simple system; it is mainly comprised of one or more butterfly valves actuated by an electrical motor through a reduction system. The throttle dynamic behavior is rendered complex by packaging, cost, and reliability constraints. These constraints often translate into dominant friction and backlash behavior in the transmission, making the control of the valve difficult. In the scientific literature, several control strategies have been proposed for throttle actuation in cars with the common aim of achieving good tracking performance in all working conditions and in the face of parametric uncertainties and avoiding overshoots, which are the main source of discomfort for the driver (see, e.g., [1], [4]–[9]). Electronic throttle actuation in motorcycles is far less common than in cars; consequently, little has been published on this topic in the open scientific literature so far. In particular, in [10] a solution for the ETB control of two-wheeled vehicles is proposed employing a variable structure control strategy. It is worth noting that the aforementioned manufacturing constraints become even more strict when the ETB is being designed for two-wheeled vehicles, especially for racing motorcycles. Mass and volumes optimization becomes critical since racing motor- cycles are very sensitive even to small changes in the center of mass, see, e.g., [11]–[13]. Furthermore, racing applications 1063-6536/$26.00 © 2010 IEEE