3 research outputs found
Robust sideslip angles observer for accurate off-road path tracking control
International audienceThis paper proposes a control strategy to achieve high accurate path tracking in off-road conditions. The approach is based on adaptive and predictive techniques to account for sliding effects and actuator properties. An extended kinematic model is designed using sideslip angles definition. An observer is proposed to estimate online these variables, independently from the reference path and robot velocity. Thanks to the proposed approach, high accurate path tracking can then be achieved whatever the shape of the reference path and the task to be achieved (practical stabilization or moving object tracking)
Integrating Vehicle Slip and Yaw in Overarching Multi-Tiered Automated Vehicle Steering Control to Balance Path Following Accuracy, Gracefulness, and Safety
Balancing path following accuracy and error convergence with graceful motion
in steering control is challenging due to the competing nature of these
requirements, especially across a range of operating speeds and conditions.
This paper demonstrates that an integrated multi-tiered steering controller
considering the impact of slip on kinematic control, dynamic control, and
steering actuator rate commands achieves accurate and graceful path following.
This work is founded on multi-tiered sideslip and yaw-based models, which allow
derivation of controllers considering error due to sideslip and the mapping
between steering commands and graceful lateral motion. Observer based sideslip
estimates are combined with heading error in the kinematic controller to
provide feedforward slip compensation. Path following error is compensated by a
continuous Variable Structure Controller (VSC) using speed-based path manifolds
to balance graceful motion and error convergence. Resulting yaw rate commands
are used by a backstepping dynamic controller to generate steering rate
commands. A High Gain Observer (HGO) estimates sideslip and yaw rate for output
feedback control. Stability analysis of the output feedback controller is
provided, and peaking is resolved. The work focuses on lateral control alone so
that the steering controller can be combined with other speed controllers.
Field results provide comparisons to related approaches demonstrating
gracefulness and accuracy in different complex scenarios with varied weather
conditions and perturbations