SARTRE: SAfe Road TRains for the Environment Arturo Dávila Mario Nombela IDIADA Automotive Technology SA London Heathrow, September 21, 2010. The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement n 233683
INDEX The SARTRE Project Project Objectives Expected Benefits Environmental Safety Traffic Flow Project Activities Fuel Consumption Simulation Fuel Consumption Evaluation Proving Ground Testing Real Traffic Evaluation
The SARTRE Project Project Objectives Expected Benefits Environmental Safety Traffic Flow Project Activities Fuel Consumption Simulation Fuel Consumption Evaluation Proving Ground Testing Real Traffic Evaluation
SARTRE: SAfe Road TRains for the Environment The main objective of the SARTRE project is to create a fully functional road train comprised of lead vehicle (driven by a professional) and following vehicles (driven autonomously) and to demonstrate the system in operation. SARTRE aims at encouraging an evolutional change in the use of personal transportation through the development of safe and environmental road trains (platoons). The project addresses three cornerstones of transportation issues: environment, safety and congestion while also encouraging driver acceptance through increased driver comfort. SARTRE is a three year project within the 7th Framework Programme in which 7 partners from all over Europe participate actively.
SARTRE: SAfe Road TRains for the Environment Source: VOLVO
The SARTRE Project Project Objectives Expected Benefits Environmental Safety Traffic Flow Project Activities Fuel Consumption Simulation Fuel Consumption Evaluation Proving Ground Testing Real Traffic Evaluation
Project Objectives Define a set of acceptable platooning strategies that will allow road trains to operate on public motorways without changes to the road and roadside infrastructure. Enhance, develop and integrate technologies for a prototype platooning system such that a number of the defined strategies can be assessed under real world scenarios. Show how platoons can lead to environmental, safety and congestion improvements. Illustrate how a new business model can be used to encourage the use of platoons with benefits to both lead vehicle operators and to platoon subscribers.
The SARTRE Project Project Objectives Expected Benefits Environmental Safety Traffic Flow Project Activities Fuel Consumption Simulation Fuel Consumption Evaluation Proving Ground Testing Real Traffic Evaluation
Environmental Benefits In the "Partners for Advanced Transit and Highways (PATH) Program" in the US during the 1990s, an average benefit of about 20 % has been estimated for highway driving. This benefit varies with the number of vehicles, the vehicle spacing and the aerodynamic geometry of vehicles. Source: PATH program Smaller spacing between vehicles gives greater benefit in terms of energy consumption but it is also more challenging for the control system.
Environmental Benefits The aerodynamic geometry of the vehicles influences the performance on platoons. A small vehicle following a large vehicle will obtain a significant benefit. Also the opposite situation will occur, but to a lesser extent. Source: PATH program In the SARTRE project, the lead vehicle of the road train will be a commercial vehicle, which are taller and wider than cars, increasing the benefit for the following vehicles.
The SARTRE Project Project Objectives Expected Benefits Environmental Safety Traffic Flow Project Activities Fuel Consumption Simulation Fuel Consumption Evaluation Proving Ground Testing Real Traffic Evaluation
Safety Benefits Human factors contribute to almost 95%* of road accidents. The road train users will benefit safety-wise from having a trained, supervised professional driver in the lead. The platoon incorporates a significant level of driving automation whereby for extended periods of time drivers of following vehicles concede their control to the lead vehicle and local autonomous systems. The combination of a trained professional driver and autonomous control system will provide an improved level of safety for all the road train users with the reduced driver intervention. *Brown, I. (2005) Review of the Looked but Failed to See Accident Causation Factor, Road Safety Research Report No. 60, Department for Transport, London.
The SARTRE Project Project Objectives Expected Benefits Environmental Safety Traffic Flow Project Activities Fuel Consumption Simulation Fuel Consumption Evaluation Proving Ground Testing Real Traffic Evaluation
Traffic Flow Benefits There are 4 principal traffic conditions: free traffic, collapsing traffic, synchronic inhomogeneous traffic and stop-go traffic*. Free traffic.- All vehicles circulate with no problems. There are long time gaps and high speeds. SARTRE platoons help delay the generation of collapsing traffic. Collapsing traffic.- Dependent on the traffic space and time gap. SARTRE platoons will provide the most benefits in this condition because the time gap is reduced to a minimum so that the road capacity can be enhanced and traffic congestions avoided or at least delayed. *http://www.invent-online.de/index.html
Traffic Flow Benefits Synchronic inhomogeneous traffic.- Characterised by density waves, where vehicles drive in between 30 and 80 km/h in 100 m distance. SARTRE platoons could provide more stable traffic flow. Source: INVENT Project* Stop-go traffic.- The beneficial effect in this condition is achieved when the platoon leaves the traffic jam, as the acceleration is adequate and controlled, maintaining the space between vehicles thus leading to a faster dissolving of the congestion. *http://www.invent-online.de/index.html
The SARTRE Project Project Objectives Expected Benefits Environmental Safety Traffic Flow Project Activities Fuel Consumption Simulation Fuel Consumption Evaluation Proving Ground Testing Real Traffic Evaluation
Project Activities Project Structure: IDIADA leads WP 4 & 5, concerning the validation of the integrated system and the overall system assessment. WP2 Concept Definition With these activities, IDIADA will carry out the work focused on improving the three cornerstones tackled by the project: WP1 Management WP3 Implementation WP6 Dissemination improved fuel efficiency and environmental benefits greater safety on the roads better traffic flow. WP4 Validation WP5 Assessment
Project Activities Project Timeline Actual Validation
Project Activities The activities to be carried out during the project for the validation purposes are: 1. Simulation of the aerodynamic performance of a platoon to calculate fuel and environmental savings. 2. Perform fuel consumption tests on track and power benches. 3. Correlate fuel consumption results from the simulation and track and power bench tests. 4. Proving ground tests to the entire system to validate the function of each individual item and the entire system altogether. This task will include platform and high speed track tests. 5. Open road tests to validate the closest to real scenario possible and to obtain data from other users.
The SARTRE Project Project Objectives Expected Benefits Environmental Safety Traffic Flow Project Activities Fuel Consumption Simulation Fuel Consumption Evaluation Proving Ground Testing Real Traffic Evaluation
Fuel Consumption Simulation To obtain a previous value of the fuel consumption benefit, a simulation of the platoon with different gap sizes will be performed. 1. The first action is to perform a coast down test to the reference vehicles on the dynamic platform one by one (coast down test with a platoon is too difficult). 2. The second step is to simulate with a Computational Fluid Dynamics Software (CFD) each of the reference vehicles to obtain the drag and lift coefficients. 3. Afterwards, the reference vehicle must be simulated with another vehicle in front, and using several different gaps. From here, new drag and lift coefficients will be obtained.
Fuel Consumption Simulation 4. Create a one-dimensional simulation model of the study vehicle, using coast down to know the work done by the engine and the fuel consumption. 5. Create a one-dimensional simulation model of the study vehicles using only physical parameters. 6. Correlate the physical and coast down parameters. 7. Once these data have been correlated, make variations in the Cd and Cl values according to the ones calculated in the CFD Software. From here, we obtain new engine work data. Source: IDIADA 8. Analysing the applied torque and rpm rate over the engine s consumption map, we could then have the comparative in consumption for each Cd and Cl value.
The SARTRE Project Project Objectives Expected Benefits Environmental Safety Traffic Flow Project Activities Fuel Consumption Simulation Fuel Consumption Evaluation Proving Ground Testing Real Traffic Evaluation
Fuel Consumption Evaluation To evaluate the real fuel savings, two methods will be used: tests in track and power benches. Testing in proving grounds is very realistic but boundary conditions are difficult to be controlled. The absence of robustness will be made up by bench testing. The pattern obtained in the proving ground will be implemented in the test benches. The results obtained will be correlated and solid values of the fuel consumption will be generated. Source: IDIADA
The SARTRE Project Project Objectives Expected Benefits Environmental Safety Traffic Flow Project Activities Fuel Consumption Simulation Fuel Consumption Evaluation Proving Ground Testing Real Traffic Evaluation
Integrated System Evaluation Full system testing will be done at the test tracks. Although physical testing is not as repeatable as laboratory testing, it is quite necessary to ensure the correct functionalities and operation of the integrated system. IDIADA will provide its proving grounds and test equipment for implementing these trials with the lead vehicle (1 truck) and following vehicles (1 SUV and 2 cars). Source: SARTRE Project Eventually, as the trials go on, an additional following vehicle (1 truck) will be added.
Integrated System Evaluation Initial testing will be performed on dynamic platforms, which are flat open areas where there is no risk of having an accident as they are closed environments, with strict control and wide run-out zones. These platforms have 6 degrees of freedom; aided by differential GPS units (accuracy ±20 mm) and to simulate surrounding traffic, rabbit vehicles will be used. These characteristics ensure that the tests are run in a safe and controlled environment. Source: IDIADA
Integrated System Evaluation Integrated system evaluation will be continued on the high speed track. Designed with several entry/exit areas from the same side as on a regular road. Total length of 7560 m, two straights of 2000 m and two bends of 1780 m. Four lanes, for which the first two lanes will be used in the project because of the speed limits and manoeuvres to be performed. Source: IDIADA
Integrated System Evaluation In this phase, the functional and operational cases of the system will be evaluated, preferably in a sequential and repeatable order. With this testing facilities, the environment is controllable (surrounding traffic, velocity, safety, test surveillance). The track allows for highway incorporation and exit giving a realistic approach for the test. The Driver-in-the-Loop concept will be used for the tests. It involves drivers with a different distribution of age, sex, size and driving skills. These tests are run under controlled environment and everyone involved is aware of the project, the emergencies, the procedures, etc For this reason, real traffic evaluation is necessary.
The SARTRE Project Project Objectives Expected Benefits Environmental Safety Traffic Flow Project Activities Fuel Consumption Simulation Fuel Consumption Evaluation Proving Ground Testing Real Traffic Evaluation
Real Traffic Conditions Test Real traffic conditions tests are necessary so that the system performs in the target environment (uncontrolled and variable) and the external input from other users is considered. Vilanova I Cubelles-Cunit Tunnels Calafell Segur de Calafell TOLL Source: Google Maps IDIADA has already proposed a section of a local highway to carry out the tests This section of the highway includes some of the most important features that a SARTRE platoon needs, assuring that real life test conditions prevail. The proposed section covers approximately 12 km.
Real Traffic Conditions Test Tests to be carried out in the real traffic scenario will include: Entrance to the road by lead and following vehicles. Creation/dissolution of road trains. Joining/leaving platoon of following vehicles. Toll booth crossings. Platoon management. The test sequence can be repeated as required and can be modified. This scenario will add the input from other vehicle users while facing a platoon on the road for the first time. This is very important for the conceptual work on the definition of platoon length and human factor perception.
Acknowledgements This project is being carried out in the framework of SARTRE Project (grant agreement n 233683), funded by the Seventh Framework Programme (FP7/2007-2013) of the European Commission. Project Partners: Project Coordinator: RICARDO Partners: IDIADA Automotive Technology Institut für Kraftfahrzeuge (IKA) SP Sweden Tecnalia-RBTK Volvo Cars Volvo Technology www.sartre-project.eu
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