CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims foreign priority benefits under 35 U.S.C. § 119(a)-(d) to European patent application number EP 17178605.6, filed Jun. 29, 2017, now European Patent No. EP 3 421 308 B1, issued Aug. 11, 2021, which is incorporated by reference in its entirety.

TECHNICAL FIELD

Embodiments herein relate generally to an autonomous vehicle and a method performed by the autonomous vehicle. More particularly the embodiments herein relate to activating an autonomous braking maneuver of the autonomous vehicle having an autonomous drive system.

BACKGROUND

In a near future, autonomous vehicles may be responsible for driving in arbitrarily complex traffic environments. The traditional driver may become a rider of the vehicle or even a customer in a self-driving shuttle without any driver present. One can imagine scenarios where the rider would like to override the vehicle and stop quickly. Hence, it is reasonable that the riders request access to an emergency stop switch of some sort, e.g., a train style emergency stop handle, etc.

In a manually driven vehicle, the driver can request an emergency braking in speed via the Electronic Parking Brake (EPB) switch. An example of an emergency braking system in a manual driven vehicle is illustrated inFIG. 1. The user of the vehicle (e.g., the driver or the passenger) can request a stop101by e.g., pressing an EPB button. The vehicle then starts the brake control102and brakes using primarily the service brakes103, if available, as long as the driver pushes the EPB button. If the service brakes103are not available e.g., due to a hydraulic system failure, the vehicle uses the EPB104to stop. Thus, the stop is performed primarily with service brakes103if available and secondarily via dynamic braking with EPB104. This maneuver is a very basic maneuver with simple longitudinal deceleration and the driver still needs to actively control the lateral movement of the vehicle. Hence, for an autonomous vehicle this emergency maneuver is not sufficient, in particular if there is no driver or even steering wheel.

The service brake in a vehicle may be described as the primary braking system. The service brake is typically operated by foot. The service brake is used in ordinary driving of the vehicle, compared to e.g., the emergency braking system. The emergency braking system, also referred to as a parking brake, or a hand brake, is a braking system that can be used in the event of failure of the service brake and to keep the vehicle from rolling when parked. The EPB104is an example of an emergency braking system. In an electronic parking brake system, the EPB104is activated by activating an electrical switch or button.

There are today no good interfaces for the user of an autonomous vehicle to stop the vehicle with autonomous support. Currently, focus is on function development with safety drivers observing the self-driving vehicle. Therefore, there is a need to at least mitigate or solve this issue.

SUMMARY

An objective of embodiments herein is therefore to obviate at least one of the above disadvantages and to provide improved braking of an autonomous vehicle.

According to a first aspect, the object is achieved by a method performed by an autonomous vehicle for activating an autonomous braking maneuver of the autonomous vehicle having an autonomous drive system. The autonomous vehicle detects at least one user initiated request for an autonomous braking maneuver of the vehicle when the vehicle is in a first autonomous drive mode at a speed. The autonomous braking maneuver is at least one of: speed reduction or stop. When the request has been detected, the autonomous vehicle activates the autonomous braking maneuver of the vehicle which reduces the speed and/or brakes the vehicle to a stop.

According to a second aspect, the object is achieved by an autonomous vehicle for activating an autonomous braking maneuver of the autonomous vehicle having an autonomous drive system. The autonomous vehicle is configured to detect at least one user initiated request for an autonomous braking maneuver of the vehicle when the vehicle is in a first autonomous drive mode at a speed. The autonomous braking maneuver is at least one of: speed reduction or stop. The autonomous vehicle is configured to, when the request has been detected, activate the autonomous braking maneuver of the vehicle which reduces the speed and/or brakes the vehicle to a stop.

Since there is enabled a user initiated request to activate an autonomous braking maneuver of the vehicle, the speed of the autonomous vehicle can be reduced and/or it can be braked to a stop. Thus, improved braking of an autonomous vehicle is provided.

Embodiments herein afford many advantages, of which a non-exhaustive list of examples follows:

An advantage of the embodiments herein is that a user of the autonomous vehicle has access to an emergency stop switch of some sort, which may be necessary if the user has a need to override the vehicle and stop quickly.

Another advantage of the embodiments herein is that the already existing EPB button may be upgraded with an autonomous safe stop, controlling both longitudinal and lateral control of the vehicle. Thus, it is not necessary to implementing a separate button for the embodiments herein.

Another advantage of the embodiment is that pressing the EPB button includes a primary autonomous safe stop function, but also that it hosts a manual function to brake the vehicle in case of autonomy system unavailability. Hence, there is enabled a single user interface for emergency stopping using either autonomous control to stop e.g., in lane or manual controlled braking to stop.

The embodiments herein are not limited to the features and advantages mentioned above. A person skilled in the art will recognize additional features and advantages upon reading the following detailed description.

