Patent Description:
During assisted, automated or autonomous driving, when following another road user at low speed, the distance the vehicle leaves to the other road user at stationary, or "stop gap" may be determined by the vehicle.

The most appropriate distance to leave to the other road user at stationary depends on a number of factors, both objective and subjective. While one can preset the "stop gap" to work in most scenarios, the remaining scenarios often leave the driver of the vehicle desiring a shorter distance to the other road user.

An autonomous driving technique is described in <CIT>.

According to an aspect of the invention there is provided a control system for a host vehicle operable in an automated driving mode, the control system comprising one or more controllers, wherein the control system is configured to:.

Throughout this disclosure, the term "automated" is used as a generic term to encompass and include terms of art such as "assisted", "self-driving" and "autonomous". No distinction is to be made between these terms unless specifically required by the context.

An advantage is an improved user interface for controlling vehicle-to-vehicle separation (e.g. stop gap) in traffic jams. This is because the driver can set a first, default stop gap using the first HMI (e.g. touchscreen), and can set a second, customized stop gap using the second HMI (e.g. accelerator pedal), for example if the conditions of that traffic jam call for a slightly reduced gap to the vehicle in front.

In some examples, the threshold is a stopping vehicle threshold.

In some examples, the vehicle-to-vehicle separation is selectable from a plurality of selectable values via the first human-machine interface, and wherein the control system is configured to enable, via the driver intervention from the second human-machine interface, adjustment of vehicle-to-vehicle separation between the plurality of selectable values. In some examples, the plurality of selectable values have intervals between <NUM> metres to <NUM> metres.

In some examples, the control system is configured to enable the updated vehicle-to-vehicle separation to be less than a smallest vehicle-to-vehicle separation selectable from the first human-machine interface.

In some examples, the control system is configured to determine whether the modified vehicle-to-vehicle separation is below a minimum separation, wherein if the modified vehicle-to-vehicle separation is above the minimum separation, the modified vehicle-to-vehicle separation becomes the updated vehicle-to-vehicle separation, and if the modified vehicle-to-vehicle separation is below the minimum separation, the minimum separation becomes the updated vehicle-to-vehicle separation. In some examples, the minimum separation is a value between <NUM> metres and <NUM> metres.

In some examples, the automated mode is an adaptive cruise control mode.

In some examples, when vehicle speed is above the threshold, the control system is configured to dynamically control vehicle-to-vehicle separation in dependence on a vehicle speed-dependent target.

In some examples, the threshold is a first threshold, and wherein the control system is configured to:
when vehicle speed rises above a second threshold greater than the first threshold, revert to the vehicle-to-vehicle separation selected from the first human-machine interface when vehicle speed later falls below the first threshold. In some examples, the second threshold is a value between <NUM>/h and <NUM>/h.

In some examples, the second threshold is configured to be less than a minimum settable vehicle speed target for the automated mode.

In some examples, the control system is configured to:.

In some examples, the second human-machine interface is configured to request drive torque when actuated. In some examples, the second human-machine interface comprises an accelerator. In some examples, the first human-machine interface is a digit-operated interface.

In some examples, updating the stored vehicle-to-vehicle separation comprises measuring the modified vehicle-to-vehicle separation following the driver intervention and a detection that vehicle speed is below the threshold.

According to an aspect of the invention there is provided a vehicle comprising the control system.

According to a further aspect of the invention there is provided a method of controlling a host vehicle operable in an automated mode, the method comprising:.

According to a further aspect of the invention there is provided computer software that, when executed, is arranged to perform any one or more of the methods described herein. According to a further aspect of the invention there is provided a non-transitory computer readable medium comprising computer readable instructions that, when executed by a processor, cause performance of any one or more of the methods described herein.

The one or more controllers may collectively comprise: at least one electronic processor having an electrical input for receiving information; and at least one electronic memory device electrically coupled to the at least one electronic processor and having instructions stored therein; and wherein the at least one electronic processor is configured to access the at least one memory device and execute the instructions thereon so as to cause the control system to cause performance of the method.

<FIG> illustrates an example of a host vehicle <NUM> in which embodiments of the invention can be implemented. The host vehicle <NUM> is stopped behind a followed road user <NUM> (e.g. another, preceding vehicle).

In some, but not necessarily all, examples the host vehicle <NUM> is a passenger vehicle, also referred to as a passenger car or as an automobile. In other examples, embodiments of the invention can be implemented for other applications, such as commercial vehicles.

The host vehicle <NUM> is operable in an automated mode. In some, but not necessarily all, examples the automated mode is an adaptive cruise control (ACC) mode.

ACC is a version of cruise control that adapts to the speed of a followed road user <NUM>. Like normal cruise control, ACC will control the speed of the host vehicle <NUM> to match a speed target. The driver may set the speed target to match a current speed and can then release the accelerator because the vehicle speed will be controlled to automatically maintain vehicle speed at the speed target. The driver can change the speed target during ACC, for example with digit (finger) controls.

The term 'automatic' herein refers to functions that are able to operate without user intervention.

In some examples, the speed target adapts automatically in dependence on traffic sign recognition, if the host vehicle <NUM> is capable of traffic sign speed limit recognition (camera and processor equipped).

ACC ensures that if the host vehicle <NUM> is approaching a preceding road user <NUM> and the road user <NUM> is travelling at a speed less than the speed target, the host vehicle <NUM> will automatically slow down to follow the road user <NUM>.

When following, ACC may control the vehicle-to-vehicle (V2V) separation to the followed road user <NUM> to maintain a target V2V separation or to avoid falling below a minimum V2V separation. If the other road user <NUM> speeds up again, the host vehicle <NUM> will automatically speed up until the speed target is reached.

When following, the target V2V separation may be preset or user-configurable. The target V2V separation may be treated as a separation time or as a speed-dependent separation distance. This ensures that the V2V separation increases as vehicle speed increases.

In at least some examples ACC works in stop-start traffic and can be referred to as 'ACC with Stop & Go'. If the followed road user <NUM> stops, the host vehicle <NUM> will stop behind the followed road user <NUM> at a particular V2V separation, labelled 'V2Vstopped' in <FIG>. This will be called 'stop gap' in the following description, to denote V2V separation when the host vehicle <NUM> is detectably stopped.

The target stop gap is distinct from the 'following-vehicle' target V2V separation in various ways. The target stop gap can be treated as a distance target that is not dependent on vehicle speed because the host vehicle <NUM> is not moving. The target stop gap may be user configurable separately from the 'following-vehicle' target V2V separation. This is useful if the driver wants ACC to follow from a long distance but not leave an excessive gap when stopping a traffic jam.

ACC may switch from the 'following-vehicle' target V2V separation to the target stop gap with a blend between the two targets, when the vehicle is detected to be stopping according to a speed sensor (not shown) and/or a zero target speed of ACC.

In the present disclosure, the ACC with Stop & Go does not require a driver resume input (e.g. accelerator pedal input or other driver input) to enable the host vehicle <NUM> to move again after stopping. In some examples the ACC with Stop & Go may require a driver resume input reactivation if the host vehicle <NUM> has been stopped for at least a threshold time such as <NUM> seconds.

Unlike Traffic Jam Assistance, the ACC of the present disclosure enables selection of a high vehicle speed target (e.g. above 60kph).

In ACC the driver may remain responsible for steering inputs and for supervision of ACC. In ACC, the driver may be able to manually longitudinally control the host vehicle <NUM> without deactivating ACC. A temporary manual increase in vehicle speed above the speed target may temporarily override conformance to the speed target and/or conformance to a particular V2V separation.

Referring to <FIG>, the ACC function is controlled by a control system <NUM>. The illustrated control system <NUM> is configured to control output torque of a torque source <NUM> to control vehicle speed and position in dependence on a signal from at least one distance-measuring sensor <NUM>. The torque source <NUM> may comprise an internal combustion engine and/or an electric machine, for example. The distance-measuring sensor <NUM> may comprise a forwardfacing radar sensor or a camera for example, providing distance-dependent information indicative of V2V separation from a followed road user <NUM> in a same lane as the host vehicle <NUM>.

In some examples the control system <NUM> can control a vehicle braking system <NUM> in dependence on the signal from the distance-measuring sensor <NUM>. The vehicle braking system <NUM> may comprise a friction braking system and/or a regenerative braking system, for example. The host vehicle <NUM> can therefore both speed up and slow down with traffic.

The control system <NUM> of <FIG> comprises a controller <NUM>. In other examples, the control system <NUM> may comprise a plurality of controllers on-board and/or off-board the host vehicle <NUM>. In some examples, a control system <NUM> or a controller <NUM> may be supplied along with one or more of the other components <NUM>, <NUM>, <NUM>, <NUM>, <NUM> shown in <FIG> as part of a system <NUM>.

The controller <NUM> of <FIG> includes at least one processor <NUM>; and at least one memory device <NUM> electrically coupled to the electronic processor <NUM> and having instructions <NUM> (e.g. a computer program) stored therein, the at least one memory device <NUM> and the instructions <NUM> configured to, with the at least one processor <NUM>, cause any one or more of the methods described herein to be performed. The processor <NUM> may have an interface <NUM> such as an electrical input/output I/O or electrical input for receiving information and interacting with external components.

<FIG> illustrates a non-transitory computer-readable storage medium <NUM> comprising the instructions <NUM> (computer software).

According to some, but not necessarily all, embodiments of the invention the control system <NUM> further enables the driver to select a target stop gap using one human-machine interface (HMI), and then perform a fine adjustment using a different HMI (e.g. accelerator pedal) which will be remembered within the same traffic jam/queue.

A first human-machine interface (HMI1 <NUM>) enables a driver to select the target stop gap. HMI1 <NUM> may comprise a digit-operated interface such as a touchscreen user interface element, a button, a switch or a dial. HMI1 <NUM> could be a dedicated 'target stop gap control' interface.

HMI1 <NUM> provides a plurality of selectable values of the target stop gap. The selectable values may include at least three values x<NUM>, x<NUM>, x<NUM> such as close-medium-far as shown in <FIG>. At least some values fall within the range four metres to six metres. All values may be less than ten metres. All values may be greater than three metres.

The selectable values have large intervals between them for convenience, but this may not suit all drivers or traffic jam contexts. Typical intervals are from the range <NUM> metres to <NUM> metre.

In an example, the selectable values include approximately <NUM> metres, approximately <NUM> metres and approximately <NUM> metres. The intervals therebetween are <NUM> metres and <NUM> metres respectively.

A second human-machine interface (HMI2 <NUM>) enables the driver to manually override the previously selected target stop gap. In this embodiment HMI2 <NUM> comprises an accelerator (e.g. accelerator pedal). HMI2 <NUM> may enable precise control of the target stop gap, to a value between the above plurality of selectable values. In other words, HMI2 <NUM> enables the target stop gap to be controlled with finer spatial granularity than HMI1 <NUM>. In some examples, HMI2 <NUM> enables the target stop gap to be controlled in a substantially continuous manner rather than as a series of discrete intervals as enabled by HMI1 <NUM>.

The accelerator pedal <NUM> is configured to request drive torque when actuated whereas HMI1 <NUM> is not. This enables the driver to creep the host vehicle <NUM> forward to the desired stop gap that will define the new target stop gap. The driver could initially select target stop gap x<NUM>, and then manually creep forward to stop gap xmod as shown in <FIG>.

The stop gap xmod can then be re-used on subsequent occasions when the host vehicle <NUM> stops within a traffic jam. In some examples the new target stop gap may be forgotten/discarded when the host vehicle <NUM> exits the current traffic jam, because drivers typically prefer different stop gaps for different types of traffic jams. For instance, the ideal stop gap in a traffic jam on a motorway or freeway may differ from the ideal stop gap in a city street, an interchange or approaching a merging of lanes.

Use of an accelerator pedal <NUM> to finely adjust the target stop gap is more intuitive and precise than other forms of control, at least due to the driver's familiarity of the amount of accelerator pedal deflection required to move the host vehicle <NUM> by a specific amount. In addition, a driver can change their mind by releasing the accelerator pedal <NUM> and can expect an immediate response.

It is also beneficial, however, to include HMI1 <NUM> for selecting the stop gap and not exclusively rely on the accelerator pedal <NUM>. This is because the control system <NUM> does not necessarily know the intention of a driver's accelerator input. For example, the driver could creep the host vehicle <NUM> forwards in order to avoid blocking a junction, without necessarily intending to change the target stop gap. Therefore, a driver may prefer to select a default stop gap from HMI1 <NUM> and only use the accelerator <NUM> for occasional temporary adjustment. After a traffic jam control will revert to the original setting from HMI1 <NUM>.

An example control method <NUM> is provided in <FIG>, for implementation by the control system <NUM> during automated following in ACC.

At operation <NUM>, the method <NUM> comprises receiving a driver selection from HMI1 <NUM> of the target stop gap (V2V separation) to be implemented in ACC when vehicle speed falls below a threshold (e.g. stopping vehicle threshold). The target stop gap may be implemented as a blend from the 'following vehicle' target V2V separation, starting from when vehicle speed falls below the threshold and when the ACC speed target is zero.

Operation <NUM> could be performed while in ACC or at another time.

At operation <NUM>, the method <NUM> comprises storing the selected target stop gap for implementation in ACC when vehicle speed falls below the threshold. The target stop gap may be stored in the memory <NUM> for example.

At operation <NUM>, the method <NUM> comprises the ACC stopping the host vehicle <NUM> at the target stop gap of operations <NUM> and <NUM>, when vehicle speed falls below the threshold. The distance-measuring sensor <NUM> may provide feedback indicative of the separation distance from the followed road user <NUM> to ensure that the control system <NUM> stops the host vehicle <NUM> at the target stop gap position.

At operation <NUM>, the method <NUM> comprises receiving a driver intervention from HMI2 <NUM> to modify the stop gap. If HMI2 <NUM> is an accelerator pedal, the modification is likely to be a reduction of the stop gap. In an implementation, receiving the driver intervention comprises detecting a torque request from HMI2 <NUM>.

The control system <NUM> may assume that the reason for this intervention is because the driver wants a smaller target stop gap. Alternatively, the control system <NUM> may prompt the driver to confirm that they wish to update the stored target stop gap.

If the driver instead uses the HMI1 <NUM> to select a new target stop gap while the host vehicle <NUM> is stopped, the change may be implemented starting from next time the host vehicle <NUM> stops. Until then, the stopped host vehicle <NUM> may stay in place without a torque request to immediately move the host vehicle <NUM> to the new target stop gap.

At operation <NUM>, the control system <NUM> updates the target stop gap in dependence on the received driver intervention. The updated target stop gap will be implemented again when the vehicle speed later falls below the threshold, for instance each time the host vehicle <NUM> subsequently stops within the traffic jam.

Operation <NUM> may comprise measuring the modified stop gap following the driver intervention and a detection that the vehicle is stopped. The measurement could utilize the distance-measuring sensor <NUM>, for example. The measurement could be initiated by the control system <NUM> when the host vehicle <NUM> is detected to have stopped. If the host vehicle <NUM> does not stop, the target stop gap may not be updated despite the host vehicle <NUM> moving closer to the followed road user <NUM>.

In a first embodiment, the updated target stop gap is the measured stop gap which replaces the previously selected target stop gap. In a second embodiment, the updated target stop gap is towards the measured stop gap but does not necessarily match the measured stop gap.

An example of the second embodiment is where the measured new stop gap is too close to be acceptable for ACC. The control system <NUM> may determine whether the measured stop gap is below a predetermined minimum stop gap. If the measured stop gap is greater than the minimum, the measured stop gap becomes the updated target stop gap. If the measured stop gap is less than the minimum, the minimum becomes the updated target stop gap.

The minimum stop gap could be a value between <NUM> metres and <NUM> metres. The minimum stop gap may be at least slightly less than a smallest target stop gap that is selectable from HMI1 <NUM>. This ensures consistent customizability regardless of which stop gap the driver originally selected from HMI1 <NUM>.

Operation <NUM> of the method <NUM> is an optional operation that limits the use of the updated target stop gap for use only within a same putative traffic jam. Operation <NUM> comprises determining whether vehicle speed is below a second threshold. A host vehicle <NUM> travelling faster than the threshold of operation <NUM> indicates that the traffic jam has ended. The threshold could be a value between approximately <NUM> kilometres per hour and approximately <NUM> kilometres per hour. An example is <NUM> kilometres per hour. In other embodiments, additional checks or different techniques could be used to determine whether the host vehicle <NUM> has left the traffic jam.

The threshold of operation <NUM> for determining whether a traffic jam has ended is not related to the speed target of ACC. The threshold of operation <NUM> may be factory-predetermined, for example, whereas the ACC speed target is driver-determined. In at least some examples the threshold of operation <NUM> is lower than a minimum selectable ACC speed target because ACC speed targets are for cruising.

For as long as the vehicle speed remains below the threshold of operation <NUM>, the method <NUM> proceeds to operation <NUM>, which comprises stopping at the updated target stop gap next time the host vehicle <NUM> stops behind a followed road user <NUM>. The method <NUM> then loops back to operation <NUM> to repeatedly check that the vehicle speed remains below the threshold of operation <NUM>.

If the speed of the host vehicle <NUM> exceeds the threshold of operation <NUM>, the method <NUM> may revert back to the original (default) target stop gap that had been selected from HMI1314 by looping back to operation <NUM>. Reverting may comprise forgetting (discarding) the updated target stop gap from HMI2 <NUM>. Next time the host vehicle <NUM> stops, the host vehicle <NUM> is treated as being in a new traffic jam so the original target stop gap from HMI1 <NUM> is initially used next time the host vehicle <NUM> stops. The driver is free to again fine-tune the target stop gap using HMI2 <NUM>, based on the characteristics of the new traffic jam.

Although not illustrated, additional or alternative means for reverting back to the original target stop gap can be provided. For example, if ACC is inhibited (deactivated) then control could revert back to the original target stop gap next time ACC is activated. ACC could be inhibited by a driver applying vehicle braking, or by actuating an inhibit function such as a digit-operated HMI (e.g. ACC 'cancel' button). Therefore, if the driver wants an updated target stop gap to be forgotten immediately, the driver can easily reset ACC by tapping a brake pedal and then reactivating ACC.

Therefore, in summary, the HMI1 <NUM> is used to select a persistent target stop gap and the HMI2 <NUM> is used to temporarily modify the target stop gap. In the above examples, persistence refers to consistency or permanence over a plurality of traffic jams and/or ACC on/off cycles.

Although embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made.

For purposes of this disclosure, it is to be understood that the controller(s) described herein can each comprise a control unit or computational device having one or more electronic processors. A host vehicle <NUM> and/or a system thereof may comprise a single control unit or electronic controller or alternatively different functions of the controller(s) may be embodied in, or hosted in, different control units or controllers. A set of instructions could be provided which, when executed, cause said controller(s) or control unit(s) to implement the control techniques described herein (including the described method(s)). The set of instructions may be embedded in one or more electronic processors, or alternatively, the set of instructions could be provided as software to be executed by one or more electronic processor(s). For example, a first controller may be implemented in software run on one or more electronic processors, and one or more other controllers may also be implemented in software run on one or more electronic processors, optionally the same one or more processors as the first controller. It will be appreciated, however, that other arrangements are also useful, and therefore, the present invention is not intended to be limited to any particular arrangement. In any event, the set of instructions described above may be embedded in a computer-readable storage medium (e.g., a non-transitory computer-readable storage medium) that may comprise any mechanism for storing information in a form readable by a machine or electronic processors/computational device, including, without limitation: a magnetic storage medium (e.g., floppy diskette); optical storage medium (e.g., CD-ROM); magneto optical storage medium; read only memory (ROM); random access memory (RAM); erasable programmable memory (e.g., EPROM and EEPROM); flash memory; or electrical or other types of medium for storing such information/instructions.

The blocks illustrated in <FIG> may represent steps in a method and/or sections of code in the computer program <NUM>. The illustration of a particular order to the blocks does not necessarily imply that there is a required or preferred order for the blocks and the order and arrangement of the block may be varied. Furthermore, it may be possible for some steps to be omitted.

Claim 1:
A control system for a host vehicle operable in an automated mode, the control system comprising one or more controllers, wherein the control system is configured to:
receive (<NUM>) a driver selection from a first human-machine interface of a vehicle-to-vehicle separation to be implemented in the automated mode when vehicle speed falls below a threshold;
store (<NUM>) the vehicle-to-vehicle separation for implementation in the automated mode when vehicle speed falls below the threshold;
characterized in that the control system is configured to:
receive (<NUM>) a driver intervention from a second human-machine interface to modify the vehicle-to-vehicle separation; and
update (<NUM>) the stored vehicle-to-vehicle separation in dependence on the received driver intervention, to be implemented when the vehicle speed later falls below the threshold and the host vehicle is operable in the automated mode.