Preliminary Study on Closed-Loop Acceleration Control of Motorcycles

In this study a preliminary investigation regarding closed-loop acceleration control for motorcycles is presented. Comprehensive considerations for the implementation of such a controller are discussed. Challenges, which are addressed, are a stable and sufficiently accurate measurement with the help of low-cost sensors and the consideration of the varying available maximum acceleration for set point calculation. In case of torque control, the maximum available torque is scaled by the throttle and thus automatically meets the limitation. Using acceleration as control variable, the varying set point limitation must be considered. According to current hypothesis, a precise closed loop control of the motorcycle longitudinal dynamics can be realized on the basis of the reference variable acceleration, yielding new possibilities in drive train control. The current control of the longitudinal dynamics is done by specifying a target output torque. However, the actual torque of the ICE is not available as a measured variable and is subject to a degree of uncertainty. In the case of a torque-based longitudinal dynamics control, the actual value can only be determined with great expense and thus a closed-loop control is not possible. Instead of the torque, the longitudinal acceleration can alternatively be used as a basis, since it is easier and less expensive to measure. The closed-loop acceleration control represents a methodology for use in future powertrains. For example, the potential use of hybrid powertrains in motorcycles raise new challenges for powertrain and vehicle control strategies. Compared to conventional drive configurations, at least two drive units contribute to the output torque, resulting in a higher control effort, which can be overcome by using acceleration control.