BACKGROUND

The present application relates to vehicle parking systems, and is particularly directed to a method and parking brake apparatus for an autonomously drivable vehicle, such as for a parking system of an autonomously drivable commercial truck.

Vehicle parking systems for commercial trucks are known. One type of vehicle parking system for trucks is an electronic parking system in which the parking brake is automatically applied using a primary parking mechanism when certain criteria associated with the truck or the truck driver are met. In some electronic parking systems, a second parking mechanism as a backup is provided for applying the parking brake in the event that the primary parking mechanism is unable to cause the parking brake to be applied. These known second parking mechanisms require the truck driver to take some manual action to activate the secondary parking mechanism after the truck driver is alerted that the primary parking mechanism has been unable to cause the parking brake to be applied.

The known secondary parking mechanisms can be used in any type of truck including autonomously drivable trucks. However, in the case of an autonomously driven truck, some manual action from an occupant of the autonomously driven truck would still be needed to activate the secondary parking mechanism if the primary parking mechanism were unable to cause the parking brake to be applied. Accordingly, those skilled in the art continue with research and development efforts in the field of parking systems of a vehicle, such as a commercial truck, that includes a primary parking mechanism, and may or may not include a secondary parking mechanism as a backup to the primary parking mechanism.

SUMMARY

In accordance with one embodiment, a parking brake apparatus is provided for an autonomously drivable vehicle having components of a parking brake system for applying a parking brake. The parking brake apparatus comprises a first controller arranged to provide one or more control signals to be applied to components of the parking brake system to apply the parking brake in response to a signal requesting the parking brake to be applied. The parking brake apparatus also comprises a second controller arranged to provide one or more control signals to be applied to other components of the parking brake system to apply the parking brake in response to unavailability of the first controller to cause the parking brake to be applied.

In accordance with another embodiment, a parking brake apparatus is provided for an autonomously drivable vehicle having components of a parking brake system for applying a parking brake. The parking apparatus comprises a primary parking brake controller arranged to control one or more parking brake valves to enable one or more parking brake springs to apply the parking brake in response to a signal requesting the parking brake to be applied. The parking brake apparatus also comprises means for, when the vehicle is autonomously driven and without requiring any manual action from an occupant of the autonomously driven vehicle, controlling the one or more parking brake valves to enable the one or more parking brake springs to apply the parking brake when the primary parking brake controller is unable to cause the parking brake to be applied.

In accordance with still another embodiment, a computer-implemented method is provided for an autonomously drivable vehicle having a parking brake, a primary parking brake controller, and a secondary parking brake controller which is different from the primary parking brake controller. The computer-implemented method comprises detecting unavailability of the primary parking brake controller to cause the parking brake to be applied. The method also comprises electronically by the secondary parking brake controller, causing the parking brake to be applied in response to the unavailability of the primary parking brake controller.

