Method and system for intelligent scaling of torque overlay intervention for semi-autonomous road vehicle steering systems

摘要

A method is provided for intelligent scaling of torque overlay intervention for a semi-autonomous steering system in a road vehicle having a semi-autonomous steering function arranged to selectively apply a steering wheel overlay torque. If decided that a driver is significantly overriding an intervention, the overlay torque is scaled by a scaling factor being a function of applied steering wheel torque. If decided that the driver has been significantly overriding the intervention for more than a pre-determined first time period, the scaling factor is set to its lowest possible value for a specific driving situation. If decided that the driver has been significantly overriding the intervention for more than a pre-determined second time period, where the pre-determined second time period is equal to or exceeds the pre-determined first time period, the scaling factor is faded-out.

主权项

1. A method for scaling of torque overlay intervention for a semi-autonomous steering system in a road vehicle having a semi-autonomous steering function arranged to selectively apply a steering wheel overlay torque, the method comprising:
determining if there is an active intervention from the semi-autonomous steering function, and a consequently applied steering wheel overlay torque; if determined that there is an active intervention, scaling the overlay torque by a scaling factor being a function of an applied steering wheel torque, and deciding if the driver is significantly overriding the intervention and duration of the overriding; if decided that the driver is significantly overriding the intervention, scaling the overlay torque by a scaling factor being a function of the applied steering wheel torque; if decided that the driver has been significantly overriding the intervention for more than a pre-determined first time period, setting the scaling factor to its lowest possible value for a specific driving situation; if decided that the driver has been significantly overriding the intervention for more than a pre-determined second time period, where the pre-determined second time period is equal to or exceeds the pre-determined first time period, fading-out the scaling factor.