WO2019170452A1

WO2019170452A1 - A method and system for longitudinal control of vehicles in a platoon

Info

Publication number: WO2019170452A1
Application number: PCT/EP2019/054540
Authority: WO
Inventors: James Nelson; Ethan OTT
Original assignee: Daimler AG
Current assignee: Mercedes Benz Group AG
Priority date: 2018-03-07
Filing date: 2019-02-25
Publication date: 2019-09-12
Anticipated expiration: 2020-09-07

Abstract

A method and system for longitudinal control of vehicles in a platoon The present disclosure relates to a system for zone based longitudinal control of vehicles in a platoon. In an aspect, system of the present disclosure can, based on input conditions, environmental conditions and horizon conditions position a following vehicle (FV) 104 in an appropriate zone that the system selects from a plurality of zones that are defined based on distance range to be maintained between a leading vehicle LV 102 and the FV 104 and speed range at which the FV 104 is to operate. The input conditions include at least deceleration status of LV 102.The environmental conditions include at least vehicle to vehicle (V2V) communication status, and the horizon conditions include an information pertaining to an upcoming event or location at which modification is required to longitudinal movement rate of one or both of the LV 102 and the FV 104.

Description

A METHOD AND SYSTEM FOR LONGITUDINAL CONTROL OF VEHICLES IN A PLATOON

PREAMBLE TO THE DESCRIPTION

The following specification particularly describes the invention and the manner in which it is to be performed:

DESCRIPTION OF THE INVENTION:

TECHNICAL FIELD

The present disclosure relates generally to vehicle management systems. In particular, it pertains to methods and systems for longitudinal control of vehicles in a platoon.

BACKGROUND

Grouping vehicles into a platoon in which vehicles travel in close proximity to one another, nose-to-tail, at highway speeds, provides many advantages. For example, some advantages are increased road capacity because vehicles travel more closely together at a steady speed. Consequently, another advantage is improved fuel efficiency for following vehicles because lead vehicle shoulders the same aerodynamic drag as regular driving, all following vehicles are able to draft the vehicle in front, and therefore experience reduced wind resistance. Studies have shown that platooning of vehicles provides significant fuel savings, with up to 10% fuel savings for following vehicles. An additional advantage of platooning is reduction in accident rate because, in theory a vehicle in the platoon is aware of what other vehicles of the platoon doing. In view of various advantages, platooning or vehicle train strategy as alternatively known in the related art, is increasingly being tried out, particularly with reference to movement of freight trucks. In particular, autonomous vehicles are very amenable to platooning in view of autonomous vehicle management techniques, which allow for vehicle to vehicle as well as vehicle to infrastructure communications leading finally to control signals to different vehicles in the platoon to control them appropriately by, for instance, maintaining a platoon configuration that can effectively utilize road the platoon is travelling upon, without causing traffic bottlenecks.

As can be appreciated, reducing air drag requires a following vehicle (FV) to be as close as possible to leading vehicle (LV). This, however, negatively impacts safety aspects that require a safe distance to be maintained between the vehicles. Since behavior of a following vehicle may not depend only on the leading vehicle but also on external factors such as a pedestrian suddenly darting on the road, an optimal balance between the two aspects of reducing air drag and safety is a challenge.

Autonomous Cruise Control (ACC), also called adaptive cruise control, radar cruise control, traffic-aware cruise control or dynamic radar cruise control, is an optional cruise control system for road vehicles that automatically adjusts vehicle speed to maintain a safe distance from vehicles ahead. Such a control is based on sensor information from on-board sensors. ACC technology improves safety and convenience as well as help increase capacity of roads by maintaining optimal separation between vehicles and reducing driving errors. Such systems may deploy wireless exchange of information amongst vehicles.

Systems such as ACC aim to maintain a fixed safe distance between two vehicles. However, such rigidity may make for less than ideal fuel economy as the maintained safe distance between two vehicles may not aerodynamically be the best, and may not be suitable for practical on road operation that have a plurality of variables that are not anticipated, such as traffic/infrastructure disturbances. Specifically, vehicle to vehicle (V2V) communication is an important requirement for smooth and safe movement of vehicles in a platoon.

United States Patent Application number US2010/0256836 discloses a method for controlling platoon formations by determining desired inter- vehicle spacing in real-time with a view to increase fuel savings. A platoon leader vehicle calculates real-time relative platoon position vectors and speeds for each follower vehicle in the group ensuring the best possible fuel savings and desirable operation. While doing so, it takes into consideration current V2V wireless communication quality (e.g., channel congestion, packet error rate); current vehicle positioning and sensor data accuracy; vehicle size and shape parameters; current and predicted vehicle speeds; dynamic capability of individual vehicles in the platoon; current road geometry; road surface; weather conditions; and current driving mode.

The cited patent reference attempts to maximize benefits of platooning by maintaining minimum distance amongst different vehicles considering limitations such as V2V wireless communication quality and other like parameters. One aspect that the cited reference fails to take into account is situations and events not yet observable by any of the vehicles and yet which can be received from other independent/third party sources and used with beneficial results in platooning. Such sources can be, for instance signals from roadside units/infrastructure and/or those provided by independent service providers (for instance, high fidelity maps, traffic information and the like). Such information can be used to advantageously improve driving behavior of the vehicles.

There is, therefore, a need in the art for a system that optimizes driving behavior of different vehicles of a platoon considering various conditions including those ascertained from signals from roadside units/infrastructure and/or those provided by independent service providers for enhanced safety and more efficiency. OBJECTS OF THE INVENTION

A general object of the present disclosure is to provide a system for longitudinal control for vehicles in a platoon that is easy and simple to implement.

An object of the present disclosure is to provide a system having an adaptive architecture for longitudinal control and coordinated braking for vehicles in a platoon.

Another object of the present disclosure is to provide a system for longitudinal control and coordinated braking for vehicles in a platoon taking into consideration various conditions including those ascertained from signals from roadside units/infrastructure and/or those provided by independent service providers.

Yet another object of the present disclosure is to provide a system for longitudinal control and coordinated braking for vehicles in a platoon that considers safety while trying to minimize aerodynamic drag.

SUMMARY

The present disclosure relates to a method and system for longitudinal control of vehicles in a platoon. In particular, it relates to a method and system that achieves reduced aerodynamic drag and fuel consumption while enhancing safety.

In another aspect, the present disclosure provides a method that includes the steps of receiving, at a computing device, any or a combination of input and environmental conditions pertaining to a Leading Vehicle (LV) and a Following Vehicle (FV). For example, the environmental conditions include at least Vehicle to Vehicle (V2V) communication status between the LV and FV, and the input conditions including at least deceleration status of the LV. Also, the present disclosure provides determining, at the computing device, a zone to which the FV should be positioned based on processing of the any or a combination of the input and environmental conditions, wherein the zone can be selected from a plurality of zones that are defined based on distance range to be maintained between the LV and the FV, and speed range at which the FV should operate; and communicating, from the computing device, to the FV the determined zone.

In another aspect, the environmental conditions can further include any or a combination of status of adaptive cruise control (ACC), and detection of a cut- in vehicle between the LV and the FV.

In yet another aspect, the input conditions can further include any or a combination of acceleration status of the LV, driving behaviour attributes of the driver of the LV, and autonomous/manual driving status of the LV.

In an aspect, the horizon conditions can further include any or a combination of road curvature information above a threshold limit, warning message, weather information, construction information, accident information, and mass mismatch between the LV and the FV above a predefined threshold.

In another aspect, on completion of the step of communicating, the FV can be brought to the determined zone by adjusting the speed of the FV and/or the distance between the LV and the FV.

In yet another aspect, the step of communicating can further include intimating a speed at which the FV is to operate or rate at which the FV is to decelerate.

In an aspect, the determined zone can be a zone in which the FV is to operate at the upcoming event or location.

In another aspect, deceleration rate of the LV can determine deceleration attributes of the FV in the same zone or to a lower speed/greater distance zone.

In an aspect, present disclosure provides a system for zone based longitudinal control of a vehicle, the system including: a non-transitory storage device having embodied therein one or more routines operable to enable zone based longitudinal control of a vehicle; and one or more processors coupled to the non-transitory storage device and operable to execute the one or more routines, wherein the one or more routines can include: a conditions receive module, which when executed by the one or more processors, can receive any or a combination of input conditions, environmental conditions and horizon conditions pertaining to a leading vehicle (LV) and a following vehicle (FV). The environmental conditions include at least vehicle to vehicle (V2V) communication status between the LV and FV, the input conditions include at least deceleration status of the LV, and the horizon conditions include an information pertaining to an upcoming event or location at which modification is required to longitudinal movement rate of one or both of the LV and the FV. The disclosed system also includes a zone determination module, which when executed by the one or more processors, can determine zone in which the FV is required to be positioned based on processing of the any or a combination of the input conditions, the environmental conditions and the horizon conditions. The zone can be selected from a plurality of zones that can be defined based on distance range to be maintained between the LV and the FV, and speed range at which the FV should operate. The disclosed system further includes a zone communication module, which when executed by the one or more processors, can communicate to the FV the determined zone.

In another aspect of the system, the environmental conditions can be further selected from any or a combination of status of adaptive cruise control (ACC), and detection of a cut-in vehicle between the LV and the FV, the input conditions can be further selected from any or a combination of acceleration status of the LV, driving behaviour attributes of the driver of the LV, and autonomous/manual driving status of the LV, and the horizon conditions can be further selected from any or a combination of road curvature information above a threshold limit, warning message, weather information, construction information, accident information, and mass mismatch between the LV and the FV above a predefined threshold. In an aspect, the proposed system utilizes various conditions to determine different‘safe and pertinent’ distances between the vehicles (such distances interchangeably termed as intervening /trailing/following distance herein) and speed/velocity profiles based on receipt of various conditions pertaining to the vehicles. Such conditions can include those in control of the vehicle drivers/ driving systems (such conditions termed as input conditions, for instance driver of the leading vehicle braking), those not in such control but observable by them (such conditions termed as environmental conditions, for instance a vehicle cutting in between the LV and the FV) and those neither in control nor observable by them yet pertinent to their driving/platooning (such conditions termed as horizon conditions, as elaborated hereunder).

In another aspect, horizon conditions can include conditions/information pertaining to map information such as road curvature, warnings from road side units/infrastructure (that can be received, for instance, using V2X signals and dedicated short range communications (DSRC) and Decentralized Environmental Notification Messages (DENM)) or from an information provider enabled by a backend cellular connection to a web service provider and safety pertinent information such as a mass or braking performance mismatch between the lead truck and the following truck. The horizon conditions along with the input conditions and the environmental conditions can be used to command a greater following distance or a slower velocity for the truck pair/platoon given its interactions with the environment.

In yet another aspect, on receipt of various conditions/information pertaining to them, the proposed system can determine the most optimal intervening/trailing distance between the two vehicles and their velocity profiles. Such distances and velocity profiles can be configured as different‘zones’ and the proposed system can position the LV and/or the FV in a determined zone, or send them relevant information to enable drivers/ autonomous driving systems in the vehicles to achieve the determined zone. It can be appreciated that either the FV or the LV can be adjusted to vary the trailing distance and the velocity profile of both FV and LV should remain substantially the same after the required trailing distance has been achieved in order for the two vehicles to still remain paired and so make a platoon formation.

Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

FIGs. 1A and 1B illustrate an overall architecture view of the proposed system in accordance with embodiments of the present disclosure.

FIG. 2 illustrates exemplary functional modules of the proposed system in accordance with embodiments of the present disclosure.

FIG. 3 illustrates various longitudinal control zones and velocity based zone lengths in accordance with embodiments of the present disclosure.

FIG. 4A tabulates environmental events and corresponding impact on variable following distance (zones) in accordance with an exemplary embodiment of the present disclosure.

FIG. 4B tabulates deceleration rate based on zone and deceleration request type in accordance with an exemplary embodiment of the present disclosure.

FIG. 4C illustrates a system response matrix showing various horizon conditions and response of the proposed system in accordance with an exemplary embodiment of the present disclosure. FIG. 5 illustrates an exemplary flow diagram for method for longitudinal control of vehicles in a platoon in accordance with embodiments of the present disclosure.

DETAILED DESCRIPTION

The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.

Embodiments described herein relate to a method and system for longitudinal control of vehicles in a platoon. In particular, it relates to a method that achieves reduced aerodynamic drag and enhanced safety. Specifically, the present disclosure provides a zone based longitudinal control system for vehicles running in a platoon, wherein each zone defines a distance range between a leading vehicle (LV) and a following vehicle (FV) along with a speed range that the FV needs to follow, and such zones being implemented depending on various conditions including those ascertained from signals from roadside units/infrastructure and/or those provided by independent service providers for enhanced safety and more efficiency. Aim of the disclosure being to achieve a ‘safe and pertinent’ distance between vehicles in a platoon, such distance being one that enables effective autonomous vehicle management as required for low aerodynamic drag, as well as enhanced safety.

In an aspect, two vehicles can be paired with Vehicle to Vehicle communication (V2V), and Adaptive Cruise Control (ACC) activated for both vehicles. It is envisaged that under normal/default driving conditions, the FV will default to a Zone that minimizes its distance from FV and thereby minimizes aerodynamic resistance on the FV for maximizing fuel efficiency. Depending on different conditions, the FV can be moved to different zones.

As can be readily appreciated, the distance range/zone will depend on driving conditions such as acceleration, deceleration etc. over which the vehicles may have some control, such conditions being termed as input conditions; as well as environment conditions such as a vehicle cutting in between the LV and the FV, loss of V2V communication and the like, over which the vehicles may have no control.

As can be readily understood, low aerodynamic drag requires low trailing distance while increased safety requires high trailing distance. The proposed system aims to achieve an optimal balance/trade-off, depending on dynamic driving conditions and environmental conditions.

In another aspect, the concept of zone based longitudinal control requires a following vehicle in a pair to be allowed to follow a lead vehicle at a pre-defined distance (say 15 meters, for instance) only when all necessary input conditions and environment conditions are met. The basic conditions for zone based longitudinal control can include: ACC enabled in both vehicles, V2V initiated in both vehicles; and pairing initiated in both vehicles. If specific input and environmental conditions are not met but pairing is possible, FV can be commanded to follow at a greater following distance. The following distances can be configured as different zones, wherein the distances that define each zone can be varied according to speed of the vehicles.

Further, each zone can define a velocity profile of the vehicles and/or a“safe and pertinent” following distance between them so that the platoon performs optimally bearing in mind safety and aerodynamic drag. Different parameters can be given different weightages while configuring zones. For instance, higher weightage may be given to speed while aerodynamic drag/fuel consumption may have a lower weightage or may be ignored altogether. It can readily be appreciated that for effective platooning, under normal circumstances, speed of various vehicles in a platoon should be same as that of a leading vehicle so as to maintain constant intervening/trailing distance. Hence, velocity profile can be interchangeably interpreted as that of the platoon or any vehicle in the platoon.

In an aspect, a zone in which a vehicle should be positioned can depend on driving conditions such as acceleration, deceleration etc. over which the vehicles may have some control, such conditions being termed as input conditions herein; as well as environment conditions such as a vehicle cutting in between the LV and the FV, loss of V2V communication and the like, over which the drivers of the vehicles may have no control but such conditions may be observable by them/driving systems configured in their vehicles.

In yet another aspect, there can be conditions that are neither directly observable by any of the vehicles nor in their control, but if known, can as well be used to control the driving behavior of the vehicles so as to achieve an optimal zone/ driving behavior. For instance, there may be situations wherein there is a traffic block due to a broken down vehicle some kilometers ahead due to which platoon would need to slow down. In that case, speed of the platoon vehicles may be reduced much before reaching the spot without using brakes in such a manner that on reaching the spot the following vehicles are positioned in an optimal zone. Not using the brakes but instead employing natural aerodynamic forces to reduce speed of the vehicles can substantially improve vehicle efficiency and accordingly, reduce fuel consumption besides reducing unnecessary wear and tear such as of the engines and braking components. Such conditions/events can be termed as horizon conditions. Further, when (or before) the vehicles arrive at the location where the horizon condition (such as a breakdown) occurred, they may already have achieved the most optimal zone suitable to the horizon condition. For instance, if a horizon condition indicates that two kilometers ahead there is slow traffic at an approximate speed of 40 KMPH while present speed of a platoon is 60 KMPH, the proposed system can set an automatic deceleration so that brakes are minimally used and aerodynamic drag itself slows down the platoon so that two kilometers later the platoon has achieved speed of 40 KMPH using least amount of fuel.

In an aspect, the proposed system can get information about such horizon conditions, also referred to as horizon events, from systems such as map information systems that can provide information pertaining to road curvatures and/or gradients ahead, V2X systems that can use road side units/ infrastructure to generate appropriate warnings and further transmit them to appropriate warning systems using, for instance, dedicated short range communications (DSRC) or Decentralized Environmental Notification Messages (DENM), or from an information provider enabled by a backend cellular connection to a web service provider (for instance CAR2X or its extension adapted for trucks termed Truck2X being developed by Mercedes-Benz). Likewise, similar pertinent information can include a mass or braking performance mismatch between the leading truck and the following truck. All such inputs can be incorporated to determine a greater following distance or a slower velocity for the truck pair (i.e., zone where the following vehicle may be positioned), given its interactions with the environment.

As is known, in a CAR2X or Truck2X system, various events are reported by polling the Controller Area Network (CAN), a standard used in specialized internal communications networks that interconnect components inside a vehicle, on vehicles for specific state changes (such as traction control events, windshield wiper or fog light use, all of which could signify inclement weather), and reception of DENM messages or user reported events such as construction zones or wrecked/disabled vehicles via the infotainment system. These events are sent to the cloud when the event occurs or is reported by the driver and are then pulled from the cloud by other data users (data ping time is usually 5-10 seconds). This data is currently only being used to create audio/visual driver warnings on the in-vehicle navigation system. The proposed system can use such events/conditions, and data/signals pertaining to those events/conditions, not only for creating driver warnings but to help define a‘safe and pertinent’ following distance and develop a velocity profile for the paired vehicles/platoon or an autonomously driving system. For instance, a traffic jam, construction zone or inclement weather can be detected over such a system and such conditions can be used by the proposed system for various actions, including but not limited to, enabling pairing, dissolving pairing, develop a velocity profile for a single vehicle or paired vehicles /platoon, command a longer following distance before approaching the situation or being notified by DENM messages only which could include an audio and/or visual pop-up on a paired vehicle’s navigation system. Presently, if a truck gets only warning from DENM it has a maximum of 7 second to warn the driver and increase the intervening distance /change longitudinal control functionality. The proposed system can aggregate such DENM messages over back end and/or to the concerned vehicles/trucks thereby allowing more time to modify responses of autonomous driving systems in the vehicles and/or notify drivers of concerned vehicles. In this manner, the proposed system can, for instance, increase‘vision horizon’ by warning a driver or driver assistance systems up to five minutes (while travelling at 65mph) before approaching a reported event.

As can be readily understood, determination of such events should not replace safety critical contents of DSRC based V2V safety message, or equivalent such messages such as lead vehicle deceleration which enables the close following distances for pairing. The proposed system can be configured accordingly.

In an aspect, the present disclosure provides a method that includes the steps of receiving, at a computing device, any or a combination of input and environmental conditions pertaining to a Leading Vehicle (LV) and a Following Vehicle (FV). For example, the environmental conditions include at least Vehicle to Vehicle (V2V) communication status between the LV and FV, and the input conditions including at least deceleration status of the LV. Also, the present disclosure provides determining, at the computing device, a zone to which the FV should be positioned based on processing of the any or a combination of the input and environmental conditions, wherein the zone can be selected from a plurality of zones that are defined based on distance range to be maintained between the LV and the FV, and speed range at which the FV should operate; and communicating, from the computing device, to the FV the determined zone.

In yet another aspect, the step of communicating can further include intimating speed at which the FV is to operate or rate at which the FV is to decelerate.

In another aspect of the system, the environmental conditions can further include any or a combination of status of adaptive cruise control (ACC), and detection of a cut-in vehicle between the LV and the FV, the input conditions can be further selected from any or a combination of acceleration status of the LV, driving behaviour attributes of the driver of the LV, and autonomous/manual driving status of the LV, and the horizon conditions can be further selected from any or a combination of road curvature information above a threshold limit, warning message, weather information, construction information, accident information, and mass mismatch between the LV and the FV above a predefined threshold.

In an aspect, the proposed system utilizes various conditions to determine different‘safe and pertinent’ distances between the vehicles (such distances interchangeably termed as intervening /trailing/following distance herein) and speed/velocity profiles based on receipt of various conditions pertaining to the vehicles. Such conditions can include those in control of the vehicle drivers/driving systems (such conditions termed as input conditions, for instance driver of the leading vehicle braking), those not in such control but observable by them ( such conditions termed as environmental conditions, for instance a vehicle cutting in between the LV and the FV) and those neither in control nor observable by them yet pertinent to their driving/platooning (such conditions termed as horizon conditions, as elaborated hereunder).

In another aspect, horizon conditions can include conditions/information pertaining to map information such as road curvature, warnings from road side units/infrastructure ( that can be received, for instance, using V2X signals and dedicated short range communications (DSRC) and Decentralized Environmental Notification Messages (DENM)) or from an information provider enabled by a backend cellular connection to a web service provider (for instance Truck2X) and safety pertinent information such as a mass or braking performance mismatch between the lead truck and the following truck can be used to command a greater following distance or a slower velocity for the truck pair/platoon given its interactions with the environment.

In yet another aspect, on receipt of various conditions/information pertaining to them, the proposed system can determine the most optimal intervening/trailing distance between the two vehicles and their velocity profiles. Such distances and velocity profiles can be configured as different‘zones’ and the proposed system can position the LV and/or the FV in a zone determined, or send them relevant information to enable drivers/ autonomous driving systems in the vehicles to achieve the zone determined. It can be appreciated that either the FV or the LV can be adjusted to vary the training distance and the velocity profile of both FV and LV should remain substantially the same after the required trailing distance has been achieved in order for the two vehicles to still remain paired and so make a platoon formation.

FIG. 1 illustrates an overall architecture view of the proposed system in accordance with embodiments of the present disclosure. As shown therein, the proposed system 100 can be in operative communication with at least two vehicles for the purpose of platooning the two vehicles. Of these vehicles, one can be a leading vehicle (LV) 102, and the other can be a following vehicle (FV) 104. Utilizing one or more of various techniques known such as adaptive cruise control (ACC), the proposed system can get relevant data from the vehicles as well as issue relevant commands to them. Such commands can carry information that can be acted upon by drivers or autonomous system of the vehicles to enable the vehicles to maintain and keep a platoon formation. In an exemplary embodiment, the commands can carry control signals for engine controllers of the respective vehicles to enable autonomous driving and automatic platooning of the vehicles as per pre-determined configurations.

It can be appreciated that while the present disclosure describes various embodiments using examples of two vehicles, concepts and techniques of the present disclosure can be applied for any platooning wherein more than two vehicles are deployed.

It should also be appreciated that the system of the present disclosure (or any part thereof) can be configured in any of a central location such as a server, or can very well be configured in one or both of the LV and the FV. Therefore, any implementation of the proposed system/technique that can help evaluate and assign a particular zone to the FV using methods elaborated herein is well within the scope of the present invention. In an aspect, the proposed system can configure trailing/intervening distance between LV 102 and FV 104 in terms of pre-configured zones, such zones belong implemented depending on input conditions, environmental conditions, and horizon conditions. Input conditions can pertain to those easily detectable/receivable by the system since they pertain to actions being taken by drivers of the vehicles or autonomous driving systems within. Environmental conditions can include those that are observable by the system since they are happening in immediate vicinity of the platooning vehicles, but are not in their control. These environmental conditions can include, for instance, a vehicle cutting in between LV 102 and FV 104. It is important to appreciate that even for such environmental conditions, the system can get information without relying on an external system/service provider. For instance, a vehicle cut-in can be determined based on video inputs received from any or both of LV 102 and FV 104.

In an aspect, the proposed system can also receive information about events/conditions that are neither in control of the vehicles’ drivers/autonomous driving systems, nor they are in the vicinity of platooning vehicles but may be useful for efficient platooning. Such events/conditions referred to as horizon conditions, and data/information regarding such events/conditions can be received from various sources, including third party service providers as discussed earlier.

In an exemplary embodiment, as illustrated in FIG 1A, the proposed system 100 can configure LV 102 and FV 104 as a platoon with FV 104 following LV 102 with an intervening distance that can lie in Zone 2 refer to FIG.3). For the purpose, the system 100 can exchange data including control signals with LV 102 as well as FV 104. Such a zone can be maintained using autonomous driving systems (such as adaptive cruise control) or by providing appropriate commands/instructions to the drivers/autonomous controls of the vehicles. In another aspect, during an implementation, the proposed system can receive information regarding input conditions 106, environmental conditions 108 and horizon conditions 110. Horizon conditions 110 can include, for example, a traffic jam some kilometers ahead due to various reasons such as an accident, a broken down vehicle, construction zone ahead and the like.

In yet another aspect, based on receipt of various conditions as above, the proposed system can determine a zone in which the vehicles should be positioned in order to achieve objectives of platooning. On such determination, the proposed system can communicate the determined zone information to FV 104, based on which an appropriate system (for instance an engine controller) within FV 104 can position the FV 104 in the determined zone.

As can be appreciated, the proposed system can communicate the determined zone information to the LV, or to both the LV and the FV so that the FV can position the FV in the determined zone since a zone includes a distance range between the two vehicles and such positioning of FV104 can be done by appropriately controlling, not only the FV 104, but any or both of the FV 104 and the LV 102.

FIG. 2 illustrates an exemplary system diagram showing functional modules of the proposed system in accordance with an exemplary embodiment of the present disclosure. As shown, the system 100 can have a conditions receive module 202, a zone determination module 204, and a zone communication module 206. In an aspect, these modules can be configured in appropriate computing systems such as personal computers, mobile devices, cloud and the like. The modules can be spread across different systems/devices or can be configured at one location itself. In an exemplary embodiment, the system can be configured in the cloud and can exchange data with a leading vehicle and a following vehicle that are being platooned by means of various sensors, autonomous driving systems and the like configured in the vehicles. In a similar manner, the proposed system can send signals to the vehicles. Based on such signals, drivers of the vehicles can take appropriate actions. In an alternate exemplary implementation, the vehicles can be configured with engine controllers and the proposed system can send out appropriate signals for the engine controllers to enable them to take appropriate action.

Conditions Receive Module 202

In an aspect, condition receive module 202 can receive any or a combination of input conditions, environmental conditions, and horizon conditions pertaining to a LV) and a FV, the environmental conditions including at least V2V communication status between the LV and FV, and the input conditions including at least deceleration status of the LV.

In another aspect, the environmental conditions can further include any or a combination of status of ACC, and detection of a cut-in vehicle between the LV and the FV. In yet another aspect, the input conditions can also be any or a combination of acceleration status of the LV, driving behavior attributes of the driver of the LV, autonomous/manual driving status of the LV.

In an aspect, the horizon conditions can include any or a combination of road curvature information above a threshold limit, warning message, weather information, construction information, accident information, and mass mismatch between the LV and the FV above a predefined threshold.

In an aspect, condition receive module 202 can determine various environmental events/conditions occurring in any of the vehicles or in their vicinity over which the vehicle drivers/their autonomous driving systems have no control, can be received by the vehicles and sent to the proposed system. In an exemplary embodiment, a camera configured in a vehicle can give information, for instance, of a vehicle’cutting-in’ between a leading vehicle and its corresponding following vehicle. Such a vehicle may not be part of the platoon itself, or may not be following its configured track for various reasons. For example, this vehicle may have been forced to change its track to avoid collision with another vehicle that has broken down. In exemplary implementation, such environmental events can also include any or a combination of V2V communication loss for a predetermined period or a predetermined number of messages, adaptive cruise control being non functional in any vehicle, manual driving of a vehicle, cut-in between vehicles etc.

In an aspect, condition receive module 202 can determine various events/conditions occurring in any of the vehicles, or any other event over which the vehicle drivers/their autonomous driving systems have control, such events/information being termed as input events/ conditions.

In an exemplary embodiment, an input event can be, for instance, driver of the leading vehicle applying brake requiring the leading vehicle to decelerate rapidly to maintain the platoon formation. The rate of deceleration may be unknown. In another exemplary embodiment, the deceleration may be caused by an adaptive cruise control system in which case the rate of deceleration may be known.

In another exemplary embodiment, an input event can be comfort range deceleration triggered by the LV ACC configured in the LV. Such comfort range deceleration can be, for instance less than 3 meters/s2.

In yet another exemplary embodiment, an input event can be safety range deceleration of an LV due to automated emergency braking (AEB) deployed by the LV driver assistance system to prevent an imminent collision with vehicle in front. Such safety range deceleration can be, for instance more than 3 meters/s2. The driver assistance system in the LV can take this decision, and on such occurrence a signal/flag that a AEB has been triggered in the LV can be sent using V2V communication to FV. Such a signal can cause a braking cascade not only in the FV but also vehicles behind the FV, whether they are in visual line of sight with any vehicle in the train or not. In alternate exemplary embodiments, condition receive module 202 can also get inputs about horizon conditions /events from different sources such as map information systems that can provide information pertaining to road curvatures and/or gradients ahead, V2X systems that can use road side units/ infrastructure to generate appropriate warnings and further transmit them to appropriate warning systems using, for instance dedicated short range communications (DSRC) or Decentralized Environmental Notification Messages (DENM), or from an information provider enabled by a backend cellular connection to a web service provider (for instance CAR2X or its extension adapted for trucks termed Truck2X being developed by Mercedes Benz.

In another aspect, condition receive module 202 can send all the received information regarding input conditions, environment conditions and horizon events/conditions to zone determination module 204 for appropriate action.

Zone Determination Module 204

In an aspect, zone determination module 204, based on processing of any or a combination of the input conditions, the environmental conditions and the horizon conditions as received by it from condition receive module 202, can determine zone to which the FV is to be positioned, wherein the zone can be selected from a plurality of zones that are defined based on distance range to be maintained between the LV and the FV, and speed range at which the FV is to operate.

As can be appreciated, zone determined by zone determination module 204 can also be the one in which the FV is currently present. Further, the determined zone can depend on the deceleration rate of the LV. The deceleration rate of LV can as well determine deceleration attributes of the FV and such attributes can be implemented using coordinated braking. In another aspect, the zone determined by zone determination module 204 can be a zone in which the FV is to operate at the upcoming event or location.

In an aspect, zone determination module 204 can send information regarding current as well as determined zone to zone communication module 206.

Zone Communication Module 206

In an aspect, zone to zone communication module 206 can communicate the zone determined by zone determination module 204 to the FV. The communication to the FV can include speed at which the FV is to operate or the rate at which the FV should decelerate so as to achieve the determined zone. The communication can include an appropriate variable braking command for the FV.

In an exemplary embodiment, the FV can include an engine controller/ coordinated braking module that can, on receipt of such communication, adjust speed of the FV and/or distance between the FV and the LV to bring the FV to the determined zone.

In an exemplary embodiment, the communication can include appropriate commands to the FV based on present zone and occurrence of an environment event/ condition, as illustrated in FIG. 4A.

In another exemplary embodiment, coordinated braking can be deployed between the FV and the LV based on an input event/condition and the present zone of the FV, as illustrated in FIG. 4B.

In yet another exemplary embodiment, coordinated braking/ accelerating can be applied on the FV and the LV based on a horizon event/condition and the present zone of the FV, as illustrated in FIG. 4C.

FIG. 3 illustrates various longitudinal control zones and velocity based zone lengths in accordance with an exemplary embodiment of the present disclosure. Vehicle to vehicle communication between LV and FV can initiate pairing between the two vehicles. Both the vehicles can be equipped with ACC that can be activated. This can enable the following vehicle to remain in a pre determined ‘default zone’ illustrated as Zone 3 under normal platooning conditions.

In another aspect, under various other scenarios, the proposed system can enable following vehicle to shift to other zones such as Zone 0, Zone 1, Zone 2, and Zone 3. The proposed system can enable longer trailing/following distances between the two vehicles by using coordinated braking so that the trailing distance falls into one of the zones pre-configured for the new scenario. The system can use various inputs for its operation.

In an aspect, zones can be configured on basis of expected range of vehicle speed. For instance, the default Zone 3 can prescribe a distance range of 30-15 meters with vehicle speed of 80 Km/hour which can be lowered to 20-15 meters at vehicle speed of under 40 Km/hour. As can be appreciated, the intent in platooning is to minimize aerodynamic drag for increased fuel efficiency, and an excellent V2V communication is essential for efficient platooning. Both these aspects can be well served in Zone 3. Further, as speeds go down and the vehicles need lesser distance to stop, the intervening/trailing distance can be brought down still further as is illustrated by a Zone 3 length of 20-15 meter at speeds under 40 Km/hour. Hence, Zone 3 serves the basic premise of‘safe and pertinent’ distance well.

In another aspect, length of various zones can be fixed or variable based on various factors. For instance, during a fog event, each zone can be of higher length while during clear weather the length can be reduced. It can be readily understood that if a FV is in Zone 3, it is nearest to LV and so experiences minimum aerodynamic drag with strong V2V communication. However, such a close distance between the two vehicles may not be safest. On the other hand, if an FV is in Zone 0, it will experience maximum aerodynamic drag. Besides, as the FV shifts away from the LV, V2V communication and hence platooning of the vehicle will become more and more difficult and unreliable. However, as the distance between the two vehicles has increased, it leads to more safety. As can be readily understood, while four zones are proposed in the exemplary embodiment, any number of zones each with its speed and distance parameters can be configured depending on requirements.

In exemplary embodiments, as illustrated in FIG.3, Zone 3 can be a trailing distance of 30-15 meters when speed of the vehicles is 80 Km/hour, down to 20-15 meters when the speed is under 40 km/hour. Likewise, Zone 2 can be a trailing distance of 45-30 meters when speed of the vehicles is 80 Km/hour, down to 25-20 meters when the speed is under 40 km/hour. Zone 1 can be a trailing distance of 60-45 meters when speed of the vehicles is 80 Km/hour, down to 30-25 meters when speed of the vehicles is under 40 Km/hour and Zone 0 can be normal ACC enabled when trailing distance is 60 meters when speed of the vehicles is 80 Km/hour and above, down to 30 meters when the speed is under 40 Km/hour. However, it is to be appreciated that above values are purely exemplary and the proposed system can be configured to implement zones as per any suitable pre-determined values for speeds and corresponding trailing distances.

In another aspect, the proposed system can enable zone based longitudinal control to make the vehicles in a platoon behave in a certain manner, provided certain other parameters and conditions are met. For instance, when ACC is enabled and V2V is initiated in both vehicles, and pairing between the two vehicles is initiated, the proposed system can enable the FV to follow the LV at a distance of 15 meters. As can be seen, the proposed system enables such trailing distance contingent on meeting certain conditions. While some of these conditions can be internal such as braking of vehicles, other conditions can depend on be external being environmental factors such as loss of V2V communication over which vehicles may have no control. In another aspect, if specific input and environmental conditions are not met but pairing is still possible, the FV can be commanded to follow the LV at a greater following/trailing distance.

FIG. 4A tabulates environmental events and their impact on variable following distances (zones) in accordance with an exemplary embodiment of the present disclosure.

In an aspect, as elaborated above, Zones 0-4 can be pre-determined/configured using the proposed system wherein such zones are the trailing/following distance between an LV and corresponding FV.

FIG. 4A tabulates environmental events and corresponding impacts on variable following distance (zones) in accordance with an exemplary embodiment of the present disclosure. As shown in the table, the disclosed system can be configured to provide different commands to FV depending on external event and zone in which the FV is presently positioned. For example, referring to cell 31, in case FV is in default Zone 3, and there is a loss in V2V communication lasting 1 second to 3 minutes in such a manner that during this timeout period at least 10 messages have been sent by either the LV or the FV (and not received by the corresponding vehicle due to loss in V2V communication), the proposed system can issue a command to position the FV to Zone 0, i.e. maintain maximum trailing distance. Further within the Zone 0, trailing distance can be determined based on vehicle speeds.

In another example implementation illustrated by cell 14, if FV is operating in Zone 1 and a cut-in vehicle is detected between the FV and LV, the proposed system issues a command to shift the FV to Zone 0 so as to maintain safety, using an ACC response. Likewise, as illustrated in cell 32, if the vehicles are operating in Zone 3 and there is a V2V communication loss that lasts more than 3 minutes, the system issues a command to shift FV to Zone 0. In an aspect, the system can also decouple/unpair the vehicles so that actions of the LV have no impact on the FV. In an aspect, the proposed system can also enable coordinated braking between LV and the FV based on determination of input events. FIG. 4B tabulates deceleration rate based on zone and deceleration request type in accordance with an exemplary embodiment of the present disclosure. In an exemplary implementation, referring to cell 11 of FIG. 4B, in case the two vehicles are in Zone 1 and LV applies brakes but final deceleration rate of the LV is not yet known, the disclosed system can enable the FV to match the LV deceleration rate. On the other hand, as illustrated in cell 31, in case the vehicles are in Zone 3 (that is, closer to each other), the system can communicate a command to the FV to shift to Zone 2 using additive braking, such additive braking providing deceleration that is 1 m/sec.2 more than the LV deceleration. Further, when the brake pedal actuation in LV generates a deceleration of more than 2m/sec.2, the system can initiate an optical/acoustical warning cascade in following vehicles while applying deceleration

In another aspect, as illustrated in row 2, a deceleration request between 0 to 3 m/sec.2 can be commanded by an adaptive cruise control or a VRDU of the LV. This request looks different on a Controller Area Network (CAN) than a lead vehicle manual braking event and so can be identified appropriately. The system can use this event determination to match LV VRDU commanded deceleration rate in the FV as illustrated, for instance, at cell 22.

In yet another aspect, as illustrated in row 3, LV can experience a safety range deceleration (greater than 3m/sec.2 deceleration) using, for instance Active Brake Assist (ABA) or VRDU. These events look different on CAN from ACC events or manual braking requests and have different specified responses to manual braking and ACC decelerations. ABA events can include an optical/acoustic warning, a haptic braking and then emergency level braking when triggered. The coordinated braking scheme in FIG. 4B shows that this original cascade will be triggered in the following vehicle/vehicles over V2V in Zones 1 and 2 and has a modified, more aggressive, response in Zone 3 (as illustrated in cell 33), including, for instance, light haptic braking, additive haptic braking and emergency braking, depending on actions being taken by the LV.

In an aspect, the goal of above configuration is retention of the ISO 26262 safety concept used by the VRDU for ABA events. An ABA event is sought to be triggered in the FV when one is triggered in the LV. However, the FV’s sensor fusion algorithm cannot determine the same scenario as it can‘see’ only the FV directly in front of it. Further, the braking cascade is different for the FV when it is at close following distances to add additional braking to increase the distance between the two vehicles. Schema as elaborated in FIG.4B enables proposed system to take care of such aspects.

FIG. 4C illustrates a system response matrix showing various horizon conditions and response of the proposed system in accordance with an exemplary embodiment of the present disclosure. Coordinated braking/ accelerating can be deployed between the FV and the LV based on the horizon event/condition and the present zone of the FV, in accordance with matrix of FIG. 4C. Different possible horizon conditions are listed in column 402, and column 404 indicates corresponding zone to which FV would move depending on its present zone. For example, as illustrated at cell 23, the FV can be in Zone 2 when a horizon condition as a Truck2X backend warning is received. The warning can indicate for instance, bad weather, construction or an accident. Based on this horizon condition, the system can command the FV is to fall back to Zone 1. On the other hand, once the warning is no longer valid or the vehicles have crossed the affected road region, the FV can again be commanded back to Zone 3 so as to meet the requirement of‘safe and pertinent’ distance.

Similarly, as illustrated at cell 31, in case the following vehicle is in Zone 3 and an external map system indicates a road curvature that is more than the predefined threshold, the system can command the FV to fall back to Zone 2.

In yet another example as illustrated at cell 34, the following vehicle may be in Zone 2 when an external system indicates a mass mismatch between trucks greater than 10,000 lbs with heavier truck in following position. Under such horizon event, the system can command the FV is to fall back to Zone 2.

FIG. 5 illustrates an exemplary flow diagram for method for longitudinal control of vehicles in a platoon in accordance with embodiments of the present disclosure. As shown, the method can include, at step 502, receiving, at a computing device, any or a combination of input conditions, environmental conditions, and horizon conditions pertaining to LV and a FV, the environmental conditions including at least V2V communication status between the LV and FV, the input conditions including at least deceleration status of the LV, and the horizon conditions including an information pertaining to an upcoming event or location at which modification is required to longitudinal movement rate of one or both of the LV and the FV.

In another aspect the method can include, at step 504, determining, at the computing device, zone in which the FV is required to be positioned based on processing of the any or a combination of the input conditions, the environmental conditions, and the horizon conditions, wherein the zone can be selected from a plurality of zones that can be defined based on distance range to be maintained between the LV and the FV, and speed range at which the FV is to operate.

In yet another aspect the method can include, at step 506, communicating, from the computing device to the FV, the determined zone.

While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE INVENTION The present disclosure provides a system for longitudinal control for vehicles in a platoon that is easy and simple to implement.

The present disclosure provides a system having an adaptive architecture for longitudinal control and coordinated braking for vehicles in a platoon.

The present disclosure provides a system for longitudinal control and coordinated braking for vehicles in a platoon taking into consideration various conditions including those ascertained from signals from roadside units/infrastructure and/or those provided by independent service providers.

The present disclosure provides a system for longitudinal control and coordinated braking for vehicles in a platoon that considers safety while trying to minimize aerodynamic drag.

Claims

CLAIMS:

1. A method comprising:

receiving, at a computing device, any or a combination of input conditions, environmental conditions, and horizon conditions pertaining to a leading vehicle (LV) and a following vehicle (FV), said environmental conditions comprising at least vehicle to vehicle (V2V) communication status between the LV and FV, said input conditions comprising at least deceleration status of the LV, and said horizon conditions comprising information pertaining to an upcoming event or location at which modification is required to a longitudinal movement rate of one or both of the LV and the FV ;

determining, at the computing device, a zone in which the FV is required to be positioned based on processing of the any or a combination of the input conditions, the environmental conditions, and the horizon conditions, wherein said zone is selected from a plurality of zones that are defined based on a distance range to be maintained between the LV and the FV, and a speed range at which the FV is to operate; and

communicating, from the computing device to the FV, said determined zone.

2. The method of claim 1, wherein the environmental conditions are further selected from any or a combination of status of adaptive cruise control (ACC), and detection of a cut-in vehicle between the LV and the FV.

3. The method of claim 1, wherein the input conditions are further selected from any or a combination of acceleration status of the LV, driving behavior attributes of the driver of the LV, and autonomous/manual driving status of the LV.

4. The method of claim 1, wherein the horizon conditions are further selected from any or a combination of road curvature information, warning message, weather information, construction information, accident information, and mass difference between the LV and the FV.

5. The method of claim 1, wherein upon the step of communicating, the FV is brought to the determined zone by adjusting the speed of the FV and/or the distance between the LV and the FV.

6. The method of claim 1, wherein the step of communicating further comprises intimating a speed at which the FV is to operate or rate at which the FV is to decelerate.

7. The method of claim 1, wherein the determined zone is a zone in which the FV is to operate at the upcoming event or location.

8. The method of claim 1, wherein deceleration rate of the LV determines deceleration attributes of the FV in the same zone or to a lower speed/greater distance zone.

9. A system for zone based longitudinal control of a vehicle, the system comprising:

a non-transitory storage device having embodied therein one or more routines operable to enable zone based longitudinal control of a vehicle; and

one or more processors coupled to the non-transitory storage device and operable to execute the one or more routines, wherein the one or more routines include:

a conditions receive module, which when executed by the one or more processors, receives any or a combination of input conditions, environmental conditions and horizon conditions pertaining to a leading vehicle (LV) and a following vehicle (FV), said environmental conditions comprising at least vehicle to vehicle (V2V) communication status between the LV and FV, said input conditions comprising at least deceleration status of the LV, and said horizon conditions comprising an information pertaining to an upcoming event or location at which modification is required to longitudinal movement rate of one or both of the LV and the FV ; a zone determination module, which when executed by the one or more processors, determines zone in which the FV is required to be positioned based on processing of the any or a combination of the input conditions, the environmental conditions and the horizon conditions, wherein said zone is selected from a plurality of zones that are defined based on distance range to be maintained between the LV and the FV, and speed range at which the FV should operate; and

a zone communication module, which when executed by the one or more processors, communicates to the FV said determined zone.

10. The system of claim 9, wherein the environmental conditions are further selected from any or a combination of status of adaptive cruise control (ACC), and detection of a cut-in vehicle between the LV and the FV, the input conditions are further selected from any or a combination of acceleration status of the LV, driving behavior attributes of the driver of the LV, and autonomous/manual driving status of the LV, and the horizon conditions are further selected from any or a combination of road curvature information, warning message, weather information, construction information, accident information, and mass difference between the LV and the FV.