Periodic Reporting for period 2 - ENSEMBLE (ENabling SafE Multi-Brand pLatooning for Europe)
Reporting period: 2019-12-01 to 2022-03-31
Significant advances in platooning technology were already made in the last decade, but to achieve the next step towards deployment of truck platooning a multi-brand approach is required. The main goal of the ENSEMBLE project is to pave the way for the adoption of multi-brand truck platooning in Europe in order to contribute to traffic safety, throughput and fuel economy.
The ENSEMBLE project has developed and demonstrated under real world conditions:
- A multi-brand platooning technology agreed between all leading European OEMs,
- Ready for standardization,
- Coping with current traffic use cases,
- And providing requirements for semi-autonomous platooning, where there is a driver in the first vehicle only, and the following vehicles are driverless.
The project has defined two different platooning levels: platooning as an autonomous function and as a support function, of which the latter has been implemented and demonstrated during the ENSEMBLE project.
The Platooning Support Function (PSF) is based on mature and proven technology. This multi-brand solution is ready for standardisation and is able to cope with all the different use cases encountered in current traffic. The PSF fits within the current legislation.
The PSF can make today’s spontaneous platooning safer (often trucks are already driving too close without help from technology today, violating regulation and safety). For example, the PSF provides in addition to a faster reacting ACC an earlier warning to the driver and the following vehicles in case of hard braking.
ENSEMBLE has also specified the Platooning Autonomous Function (PAF). The PAF gives the vision of the ENSEMBLE Partners for the future of platooning. It foresees a driver in the first truck followed by driverless trucks travelling from hub to hub. In this case, the V2V connectivity between the trucks acts as an enabler contributing to the automation of the following vehicles. The PAF is placed between a support function and a fully autonomous truck. This is because following trucks still have the first truck’s driver to navigate through traffic and reach the destination. The PAF does not fit into the current legislation in European countries. The legislation around following distances, alert human drivers and drive-and resting time need to be modified in order to enable the Platooning Autonomous Function.
The ENSEMBLE project has developed and demonstrated under real world conditions:
- A multi-brand platooning technology agreed between all leading European OEMs,
- Ready for standardization,
- Coping with current traffic use cases,
- And providing requirements for semi-autonomous platooning, where there is a driver in the first vehicle only, and the following vehicles are driverless.
The project has defined two different platooning levels: platooning as an autonomous function and as a support function, of which the latter has been implemented and demonstrated during the ENSEMBLE project.
The Platooning Support Function (PSF) is based on mature and proven technology. This multi-brand solution is ready for standardisation and is able to cope with all the different use cases encountered in current traffic. The PSF fits within the current legislation.
The PSF can make today’s spontaneous platooning safer (often trucks are already driving too close without help from technology today, violating regulation and safety). For example, the PSF provides in addition to a faster reacting ACC an earlier warning to the driver and the following vehicles in case of hard braking.
ENSEMBLE has also specified the Platooning Autonomous Function (PAF). The PAF gives the vision of the ENSEMBLE Partners for the future of platooning. It foresees a driver in the first truck followed by driverless trucks travelling from hub to hub. In this case, the V2V connectivity between the trucks acts as an enabler contributing to the automation of the following vehicles. The PAF is placed between a support function and a fully autonomous truck. This is because following trucks still have the first truck’s driver to navigate through traffic and reach the destination. The PAF does not fit into the current legislation in European countries. The legislation around following distances, alert human drivers and drive-and resting time need to be modified in order to enable the Platooning Autonomous Function.
Starting from the current state of the art, common specifications aligned between all European truck OEMs have been defined. The result is the definition of the Platooning Support Function (PSF) and the Platooning Autonomous Function (PAF). Both functions include a detailed described platooning protocol with ensured secure communication. Also an overview of the infrastructure-based communication functions (and services) concerning platooning were provided, which are based on vehicle-to-infrastructure (V2I) and infrastructure to vehicle (I2V) communication. ENSEMBLE performed the Functional Safety Analysis for both the PSF and the PAF to address hazards resulting from Electrical/Electronic malfunctions. This included all the concept phase activities of developing the item definition, Hazard Analysis and Risk Assessment (HARA) and the Functional Safety concept (FSC). Also a SOTIF (Safety of the Intended Functionality) analysis to address hazards resulting from functional insufficiencies was performed and the safety case was developed for assuring safe testing and demonstrating of the PSF.
The specifications of the PSF were implemented in 7 demonstrator trucks from all EU truck manufacturers. This implementation includes the operational and the tactical layer, as well as the interface to the strategic layer. The V2X message set, conform the ITS G5 protocol stack was implemented into a fully functional communication device.
The implemented trucks were tested, validated and demonstrated in the ENSEMBLE project. To this end a common testing methodology was defined. The tests comprised of proving ground tests (controlled environment) and open road tests (real traffic situation).
Besides the communication and dissemination activities ENSEMBLE described the current EU regulatory framework on Truck Platooning and exemption procedures for multi-brand platooning . A specific twinning cooperation was set up with the USDOT on the topic of other road users behaviour towards platooning. The first standardization activities comprised of a contribution of a separate standardization protocol stack as a part of the C-ITS protocol stack as an ‘annex to ETSI EN 302637’. Also ISO ISO 20035:2019 addressing CACC was targeted.
The specifications of the PSF were implemented in 7 demonstrator trucks from all EU truck manufacturers. This implementation includes the operational and the tactical layer, as well as the interface to the strategic layer. The V2X message set, conform the ITS G5 protocol stack was implemented into a fully functional communication device.
The implemented trucks were tested, validated and demonstrated in the ENSEMBLE project. To this end a common testing methodology was defined. The tests comprised of proving ground tests (controlled environment) and open road tests (real traffic situation).
Besides the communication and dissemination activities ENSEMBLE described the current EU regulatory framework on Truck Platooning and exemption procedures for multi-brand platooning . A specific twinning cooperation was set up with the USDOT on the topic of other road users behaviour towards platooning. The first standardization activities comprised of a contribution of a separate standardization protocol stack as a part of the C-ITS protocol stack as an ‘annex to ETSI EN 302637’. Also ISO ISO 20035:2019 addressing CACC was targeted.
• Road authorities can potentially benefit from platooning as the integration and uptake of the platooning functionality necessitates the digitization of vehicles and logistics. This potentially enables the road authorities to influence the parameters (like time gap, speed, allowed number of trucks in a platoon) according to which the trucks are driving on their pavements.
• In the current road situation at least 15% of all trucks could already benefit from platooning without having to change their behaviour. Trucks can find each other using a platoon matching service.
• Economic analysis has shown that for fleet owners there is only a direct business case for the PAF, mainly because of the expected impact on driver efficiency costs. For the platooning support function the potential benefits are more on a societal level, since it is expected to increase traffic safety, driver comfort (not assessed in the current study) and road capacity.
• The positive effect of truck platooning on road capacity increases when the percentage of trucks in the total traffic flow is high (around 20%).
• The PSF does not show an improvement in fuel consumption and emissions. This is because the PSF is following at 1,5 seconds or more, which is not significantly closer compared to the current driving situations on the roads. Looking at the PAF, with headways lower than 1 second, potential effects on fuel consumption and emissions are expected.
• When trucks platoons are relatively long, other road users will merge in between the platoon when entering the highway at a relatively low speed. To avoid dangerous situations the developed platooning system increases the gap when a cut-in vehicle is detected, but it is still advisable to avoid long platoons or to have larger time gaps in the vicinity of highway entries.
Following these conclusions, truck platooning is beneficial for road capacity and traffic flow. But truck platooning on road segments with a lot of highway entries also shows negative effects that can be mitigated by larger time gaps, limiting the platoon length and ramp metering in such areas. In this respect hub to hub platooning using dedicated (digital) infrastructure and platooning at night can be considered as a first potential viable use-case. PAF can strengthen this use case, eliminating part of the current driver shortage at night. Given the chosen approach to first develop the platooning technology/platform that can be deployed using the existing technology and under current legislation (the PSF), the PSF can bring potential safety benefits but cannot bring the expected economic benefits and impacts of platooning immediately after the project.
• In the current road situation at least 15% of all trucks could already benefit from platooning without having to change their behaviour. Trucks can find each other using a platoon matching service.
• Economic analysis has shown that for fleet owners there is only a direct business case for the PAF, mainly because of the expected impact on driver efficiency costs. For the platooning support function the potential benefits are more on a societal level, since it is expected to increase traffic safety, driver comfort (not assessed in the current study) and road capacity.
• The positive effect of truck platooning on road capacity increases when the percentage of trucks in the total traffic flow is high (around 20%).
• The PSF does not show an improvement in fuel consumption and emissions. This is because the PSF is following at 1,5 seconds or more, which is not significantly closer compared to the current driving situations on the roads. Looking at the PAF, with headways lower than 1 second, potential effects on fuel consumption and emissions are expected.
• When trucks platoons are relatively long, other road users will merge in between the platoon when entering the highway at a relatively low speed. To avoid dangerous situations the developed platooning system increases the gap when a cut-in vehicle is detected, but it is still advisable to avoid long platoons or to have larger time gaps in the vicinity of highway entries.
Following these conclusions, truck platooning is beneficial for road capacity and traffic flow. But truck platooning on road segments with a lot of highway entries also shows negative effects that can be mitigated by larger time gaps, limiting the platoon length and ramp metering in such areas. In this respect hub to hub platooning using dedicated (digital) infrastructure and platooning at night can be considered as a first potential viable use-case. PAF can strengthen this use case, eliminating part of the current driver shortage at night. Given the chosen approach to first develop the platooning technology/platform that can be deployed using the existing technology and under current legislation (the PSF), the PSF can bring potential safety benefits but cannot bring the expected economic benefits and impacts of platooning immediately after the project.