Fig. 1: Two configurations of steering HSC between human driver and automation and overview of an automated driving control framework including the proposed collaborative steering control.
From: Haptics based multi-level collaborative steering control for automated driving
The dashed lines represent the human driver control. a Blended control: The driver torque Td and the automation torque Ta track their target angles θd and θa with the feedback of the measured angle θp. The respective tracking efforts are superposed to form an electric power steering (EPS) motor torque command. The gain Gt is used for attenuating the automation effort and enabling driver intervention in shared mode. Gt is set to zero when operating the EPS in manual mode in the event of an override. b Admittance control: A virtual plant is used to estimate the manual deviation θm from the measured driver torque input Ttb. The angle control attempts to enforce the superposition angle of θa and θm by applying the command torque Tmot to the EPS. The reaction torque perceived by the driver is designed with the virtual plant and its load Ta. Similarly to blended control, the gain Gt is set to zero for manual steering. c The black blocks with the vision loops illustrate the typical structure of an automated vehicle control system. The proposed control is represented with the turquoise blocks. Arbitration allocates the control authority of the automation based on the interaction type. The driver and the automation interact through the virtual EPS. The resulting manual deviation is input into the steering angle control so as to enforce the superposition of the driver intent to the AD trajectory. Additionally, this deviation is propagated to the inclusion block to assimilate the driver intent into the trajectory planning.
