Design of Haptic Feedback Control for Steer-by-Wire

Abstract

This paper illustrates a comparison of different haptic feedback control strategies; primarily focusing on open and closed-loop methods for a Force-Feedback Steer-by-Wire system. Due to shortcomings caused by the feedback motor impedance in the open loop architecture, the tracking performance is deteriorated. Consequently it is shown that the closedloop solutions provide an improved response within the desired steering excitation range.The closed-loop possibilities, torque and position control, are designed and objectively compared in terms of performance and stability. The controller objectives are inertia compensation and reference tracking. For a given reference, the stability constraint between the controller gains responsible for the two objectives is contrasting in both the methods. Higher bandwidth is achieved for torque controller, whereas the driver arm inertia limits the position control performance. The linear system analysis is supported by the experimental results. *The research activities have been performed as a part of the ITEAM project in the European Union's Horizon 2020 research and innovation program under Marie Sklodowska-Curie Grant Agreement No. 675999.

An approach to develop haptic feedback control reference for steering systems using open-loop driving manoeuvres

“…In impedance control, the torque reference is used by the feedback controller to minimise the torque error and vice versa in admittance control for angular position. The feedback controllers ensured stability and performance as derived in [9,13,15]. For EPAS, the results have been generated using a validated vehicle model, including steering and motor models (with a motor current control).…”

“…This is due to a higher effective steering rack or pinion impedance caused by the EPAS motor and its mechanical transmission ratio, see [10, p. 176-189], [11,12]. Similarly in steer-by-wire force-feedback (SbW-FFb), the system bandwidth is affected not only by the motor impedance but also due to uncertainty in the driver arms' impedance [13]. The closed-loop control methods could provide a better hardware impedance compensation, refer [14,15] for EPAS and [13,[16][17][18][19] for FFb systems.…”

“…Similarly in steer-by-wire force-feedback (SbW-FFb), the system bandwidth is affected not only by the motor impedance but also due to uncertainty in the driver arms' impedance [13]. The closed-loop control methods could provide a better hardware impedance compensation, refer [14,15] for EPAS and [13,[16][17][18][19] for FFb systems. As a result, a reference generator that accurately represents the driver excitation part of the haptic feedback is required.…”

“…The resulting M tb,eff is then taken as an input to the inverse basic assistance for generating the reference torque signal, M tb,ref . This reference model can also be used for the open loop architecture (without feedback control) in FFb systems, as discussed in[13].…”

Musculoskeletal Driver Model for the Steering Feedback Controller

“…It provides the driver with a desired part of the steering feel. This steering feedback is dependent on the haptic control strategy [3,4], which further consists of various software functions. One of them is the basic steering assist function.…”