Steering Feedback Transparency Using Rack Force Observer
Journal article, 2022

The closed-loop electric power-assisted steering and steer-by-wire systems are non-transparent toward the environment, i.e., the tire-road interaction dynamics. To achieve driver–environment transparency, a rack force estimate is required. With the introduction of dynamic rack force observer feedback, a closed-loop interconnection is formed. Therefore, the driver coupled stability must be ensured with this interconnection. Consequently, an upper bound condition on transparency is derived using passivity for different control architectures. For selecting an observer with reasonable performance, two rack-force estimation schemes are investigated and compared, i.e., using vehicle motion signals from the inertial measurement unit sensor and the steering system sensors. Experiments indicate that the former approach has inferior performance due to vehicle inertia and signal latency, whereas in the latter approach, nonlinear estimation using second-order dynamics provides the best result; hence, it is selected to realize transparency. Finally, real-world experiments on an electric power-assisted steering vehicle illustrate the differences between non-transparent and transparent steering feedback when driving at the limits of handling on an icy road surface.

steering system

torque/position control

Haptic feedback

real-time estimation

passivity

transparency

Author

Tushar Chugh

Chalmers, Mechanics and Maritime Sciences (M2), Vehicle Engineering and Autonomous Systems

Fredrik Bruzelius

Chalmers, Mechanics and Maritime Sciences (M2), Vehicle Engineering and Autonomous Systems

Matthijs Klomp

Chalmers, Mechanics and Maritime Sciences (M2), Vehicle Engineering and Autonomous Systems

Bengt J H Jacobson

Chalmers, Mechanics and Maritime Sciences (M2), Vehicle Engineering and Autonomous Systems

IEEE/ASME Transactions on Mechatronics

1083-4435 (ISSN) 1941014x (eISSN)

Vol. 27 1-12

Steer by wire Opportunities, performance and system safety (SWOPPS)

VINNOVA (2017-05504), 2018-03-09 -- 2021-07-01.

Areas of Advance

Transport

Subject Categories

Vehicle Engineering

Control Engineering

Other Electrical Engineering, Electronic Engineering, Information Engineering

DOI

10.1109/TMECH.2022.3144245

More information

Latest update

7/17/2024