Requirements Review from EU projects: D2.1 of H2020 project ENSEMBLE
report
This document is a starting document of ENSEMBLE, gathering experiences in general and requirements in particular of past (EU) projects on truck platooning as part of WP2. In the course of writing this deliverable it turned out that no detailed public information is available on requirements or specifications. Hence this deliverable should be seen as a State of the Art. This should be a starting point in defining platooning level A: scenarios, use cases, operational conditions, driver-vehicle interaction, communication protocol, safety, and security. Input for above topics came from the European Truck Platooning Challenge (ETPC), which had a mono-brand demonstration of platooning by all European truck manufacturers in 2016. Besides that, the following projects contributed to this deliverable: CHAUFFEUR II, KONVOI, SARTRE, i-GAME, COMPANION, AUTONET2030, ROADART, CONCORDA, and AUTOPILOT. For some topics, like e.g. Driver Interaction and heterogeneous platooning, results of other projects and more academic research were reviewed as well.
Functionality
With respect to use cases and in-vehicle architectures, many commonalities are seen on a high level. However, details are often not published. This also holds for the low-level controllers used in the different projects. Moreover, tactical layer functionalities and operational layer functionalities have mostly been implemented as one ‘controller’, i.e. there was no separation between ‘common’ and ‘truck specific’ functionalities, which is needed for ENSEMBLE’s separation in a general tactical and less general operational layer. Hence, a clear task is reserved for ENSEMBLE to separate the functionalities in a way that the technology is still usable for all OEMs. Despite the substantial academic work on platooning, applied control design for heterogeneous platooning (i.e. platooning of trucks with different properties) is still an open issue. Only very limited publications deal with implementation relevant aspects and/or heterogeneity of platoons. This thus is still an open area also for ENSEMBLE.
Human factors
Many projects have addressed human factor issues, mostly for automated driving, less for platooning. Nevertheless, several well-founded methods could be used in ENSEMBLE, like e.g. the one from the AdaptIVe project. There is, however, a number of human factors knowledge gaps:
• there is a lack of data from driving in platoon in real traffic environments with real weather and lighting conditions,
• long-term effects on human behaviour from driving in platoon, ranging from days of working (8-10 hours/day) to months of daily driving in platoons are not known,
• appropriate driver training programs for platooning may be needed,
• in platooning systems, the driver of the following trucks, as result of the reduced intervehicle distance, may not be able to timely react on system failures and hazards, due to the limited view and his/her reaction time. This means that a platooning system cannot rely on the driver as fall back and consequently the automation should provide a safe solution for handling failures and hazards.
Communication
Almost all previous platooning projects used ITS-G5 communication. A message set specifically for platooning is currently being discussed. Especially the project Sweden4Platooning is of high interest to ENSEMBLE due to their goal towards standardisation of communication for platooning.
Security
No previous projects on platooning has implemented security mechanisms as far can be concluded from project deliverables. However, much work has been done for securing the communication between vehicles and between vehicles and smart infrastructure, e.g. resulting in an overall security framework for Cooperative ITS (C-ITS), which is based on the concept of Public Key Infrastructure (PKI). Hence, the ENSEMBLE project considers to use the already standardized onboard security protocol outlined in TS 103 097 V1.3.1 for reaching interoperability between different brands using ATs. However, there are additional considerations regarding performance of signage and authentication, and confidentiality of application data. These may lead to the consideration for symmetric cryptology whilst platooning, since platooning vehicles know each other. TS 103 097 has support for the exchange of symmetric keys. The requirements and specification will be worked out in D2.6.
Safety
The ENSEMBLE project will analyse the safety risks related to both functional safety (ISO26262) and SOTIF and derive requirements to lower these risks to an acceptable level. Since these activities will not only define requirements for hazards arising from E/E malfunctions but also address hazards resulting from performance limitations or insufficiencies of the function itself, the safety activities carried out for the project are enough to have a safe platoon deployment on public roads.
Infrastructure
Concerning the digital infrastructure for strategical communication (tactical and operational communication is reported in the topic ‘Communication’ above), little information is available from recent project on platooning. The used communication technology appeared to be cellular data “4G/LTE”, e.g. let platoon trucks communicate with cloud hosted services for gathering weather conditions. Only minimal real-life experience and lab test proofs are available to conclude on the requirements for services. Hence there is a potential risk that specifications are going to be incomplete and it is recommended follow the running projects/initiatives that are also targeting truck platooning like e.g. AUTOPILOT and CONCORDA. The projects performed so far do not take into account the physical infrastructure. This may pose a risk on the ENSEMBLE project since the specifications can be incomplete and are not based on (scientific) tests and proofs.
Strategic functions and services
For large scale platooning a platform to support platooning between different freight companies is required. This necessitates support in the strategic layer for revenue sharing when platooning. Relevant information may be platoon formation, position in the platoon, time, distance and route. ENSEMBLE will benefit from the results of the EU project COMPANION, where design of the strategic layer has been researched and evaluated in extended simulations and on public road, as the main partners from COMPANION involved in the design and evaluation are also partner in ENSEMBLE.
Impact
Various projects are evaluated, however, most of the projects base their estimation on simulations, as no real platooning on public road was available on the scale required for sound evaluation, and the exact details on the implemented platooning functionality is not always stated. Hence following results must be read with reservations. Fuel saving and emission reduction are in-line with each other and different studies report between 7 and 15% possible reductions (ADAPTIVE , 2017), (SARTRE Report 2011, 2018). With respect to traffic safety high numbers ranging from 43 till 60% reduction in accidents are reported, however, different projects report different numbers (i.e. truck related accidents, highway accidents, all recorded and analysed accidents in Germany). It should be noted that these numbers very much depend on what is taken as basis, trucks without any active safety systems, or already trucks with systems like Automated Emergency Braking. Sometimes the literature is unclear about this. Impact on traffic flow is expected to improve slightly due to different mechanisms like more smooth traffic flow and higher road usage as a result of smaller inter-vehicle distances, but no conclusive numbers can be stated. Moreover, this requires higher penetration rates and possibly connections to other (cooperative) applications.
Functionality
With respect to use cases and in-vehicle architectures, many commonalities are seen on a high level. However, details are often not published. This also holds for the low-level controllers used in the different projects. Moreover, tactical layer functionalities and operational layer functionalities have mostly been implemented as one ‘controller’, i.e. there was no separation between ‘common’ and ‘truck specific’ functionalities, which is needed for ENSEMBLE’s separation in a general tactical and less general operational layer. Hence, a clear task is reserved for ENSEMBLE to separate the functionalities in a way that the technology is still usable for all OEMs. Despite the substantial academic work on platooning, applied control design for heterogeneous platooning (i.e. platooning of trucks with different properties) is still an open issue. Only very limited publications deal with implementation relevant aspects and/or heterogeneity of platoons. This thus is still an open area also for ENSEMBLE.
Human factors
Many projects have addressed human factor issues, mostly for automated driving, less for platooning. Nevertheless, several well-founded methods could be used in ENSEMBLE, like e.g. the one from the AdaptIVe project. There is, however, a number of human factors knowledge gaps:
• there is a lack of data from driving in platoon in real traffic environments with real weather and lighting conditions,
• long-term effects on human behaviour from driving in platoon, ranging from days of working (8-10 hours/day) to months of daily driving in platoons are not known,
• appropriate driver training programs for platooning may be needed,
• in platooning systems, the driver of the following trucks, as result of the reduced intervehicle distance, may not be able to timely react on system failures and hazards, due to the limited view and his/her reaction time. This means that a platooning system cannot rely on the driver as fall back and consequently the automation should provide a safe solution for handling failures and hazards.
Communication
Almost all previous platooning projects used ITS-G5 communication. A message set specifically for platooning is currently being discussed. Especially the project Sweden4Platooning is of high interest to ENSEMBLE due to their goal towards standardisation of communication for platooning.
Security
No previous projects on platooning has implemented security mechanisms as far can be concluded from project deliverables. However, much work has been done for securing the communication between vehicles and between vehicles and smart infrastructure, e.g. resulting in an overall security framework for Cooperative ITS (C-ITS), which is based on the concept of Public Key Infrastructure (PKI). Hence, the ENSEMBLE project considers to use the already standardized onboard security protocol outlined in TS 103 097 V1.3.1 for reaching interoperability between different brands using ATs. However, there are additional considerations regarding performance of signage and authentication, and confidentiality of application data. These may lead to the consideration for symmetric cryptology whilst platooning, since platooning vehicles know each other. TS 103 097 has support for the exchange of symmetric keys. The requirements and specification will be worked out in D2.6.
Safety
The ENSEMBLE project will analyse the safety risks related to both functional safety (ISO26262) and SOTIF and derive requirements to lower these risks to an acceptable level. Since these activities will not only define requirements for hazards arising from E/E malfunctions but also address hazards resulting from performance limitations or insufficiencies of the function itself, the safety activities carried out for the project are enough to have a safe platoon deployment on public roads.
Infrastructure
Concerning the digital infrastructure for strategical communication (tactical and operational communication is reported in the topic ‘Communication’ above), little information is available from recent project on platooning. The used communication technology appeared to be cellular data “4G/LTE”, e.g. let platoon trucks communicate with cloud hosted services for gathering weather conditions. Only minimal real-life experience and lab test proofs are available to conclude on the requirements for services. Hence there is a potential risk that specifications are going to be incomplete and it is recommended follow the running projects/initiatives that are also targeting truck platooning like e.g. AUTOPILOT and CONCORDA. The projects performed so far do not take into account the physical infrastructure. This may pose a risk on the ENSEMBLE project since the specifications can be incomplete and are not based on (scientific) tests and proofs.
Strategic functions and services
For large scale platooning a platform to support platooning between different freight companies is required. This necessitates support in the strategic layer for revenue sharing when platooning. Relevant information may be platoon formation, position in the platoon, time, distance and route. ENSEMBLE will benefit from the results of the EU project COMPANION, where design of the strategic layer has been researched and evaluated in extended simulations and on public road, as the main partners from COMPANION involved in the design and evaluation are also partner in ENSEMBLE.
Impact
Various projects are evaluated, however, most of the projects base their estimation on simulations, as no real platooning on public road was available on the scale required for sound evaluation, and the exact details on the implemented platooning functionality is not always stated. Hence following results must be read with reservations. Fuel saving and emission reduction are in-line with each other and different studies report between 7 and 15% possible reductions (ADAPTIVE , 2017), (SARTRE Report 2011, 2018). With respect to traffic safety high numbers ranging from 43 till 60% reduction in accidents are reported, however, different projects report different numbers (i.e. truck related accidents, highway accidents, all recorded and analysed accidents in Germany). It should be noted that these numbers very much depend on what is taken as basis, trucks without any active safety systems, or already trucks with systems like Automated Emergency Braking. Sometimes the literature is unclear about this. Impact on traffic flow is expected to improve slightly due to different mechanisms like more smooth traffic flow and higher road usage as a result of smaller inter-vehicle distances, but no conclusive numbers can be stated. Moreover, this requires higher penetration rates and possibly connections to other (cooperative) applications.
TNO Identifier
972415
Publisher
European Union
Collation
100 p.