CACC
CAMP / FHWA Vehicle to Infrastructure Applications Program Cooperative Adaptive Cruise Control Projects
The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
Acknowledgement and Disclaimer This material is based upon work supported by the U.S. Department of Transportation under Cooperative Agreement No. DTFH6114H00002. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the Author(s) and do not necessarily reflect the view of the U.S. Department of Transportation.
Cooperative Adaptive Cruise Control (CACC) Projects 1. CACC Pilot Study (9/14 – 3/15) –
Paper study
–
Define a common understanding of CACC
–
Create research plan
2. CACC Small-Scale Test (21 months starting 6/15) –
Integrate a (C)ACC prototype platform into vehicles
–
Establish ACC baseline performance
–
Simulate and compare algorithms and concepts
–
Perform hazard analysis The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
CACC Pilot Study Achievements • Reviewed prior and ongoing advanced research work by the USDOT and academia • Defined CACC system for: – Single and multiple vehicle look-ahead scenarios – String stability assessment
• Identified technical and safety issues and gaps • Examined a range of questions relevant to CACC • Established assumptions and constraints for CACC application • Developed recommendations and plan for further research The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
CACC Pilot Study System Definition CACC State Transition Model • An extension of ACC • Controller alternates between ACC and CACC modes without driver intervention • Must meet required communication reliability
CC – Cruise Control ACC – Adaptive Cruise Control CACC – Cooperative ACC Manual – Manual Driving The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
CACC Pilot Study Communication Issues Open questions for DSRC • V2V messages and transmission rate for CACC
– Sufficiency and effectiveness of V2V BSM – Impact of communication latency/message loss – Required minimum message transmission rate for safe and reliable operation
• Assess
– Impact of communication channel saturation on system performance – Needs for message protocol for CACC (coordinated) platoon discovery, management and safe operation – Needs for additional communication methods (e.g. unicast communication)
• Assessment of V2V communication security implementation and system performance for CACC The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
CACC Pilot Study Research Needs Additional research is needed to assess potential benefits and performance issues associated with CACC to further investigate numerous open issues including: • Benefits and limitations of the various design choices • Detailed hazard analysis for specific concepts including such factors as the effects of reduced headway and communication loss in CACC • Impact of vehicle positioning and localization performance • Use of multiple sensor data (e.g. fusion techniques) • Communication requirements and standards • Provisioning infrastructure capabilities The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
CACC Small-Scale Test
Phase 1
Phase 2
The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
CACC Small-Scale Test Exploratory Test Vehicles equipped with the reference ACC system will be characterized using the scenarios selected for exploratory evaluation. • DSRC, radar, positioning and vehicle dynamics data will be collected and analyzed • Establish baseline performance of current ACC systems • The data will also be used to parameterize the simulation environment The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
CACC Small-Scale Test Simulation A simulation environment will be set up, including:
• A microscopic traffic simulator • Evaluation metrics and processes to explore string-stability and assess the effect of various high and low level CACC control algorithms on surrounding traffic flow • A basic vehicle dynamics model for simulation purposes • Sensor models for radar sensors and for DSRC • Interfaces to dynamically control one or more of the vehicles in the simulation by the prototype CACC algorithms being developed The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
CACC Small-Scale Test Algorithm Development Multiple algorithm concepts will be developed, tested and either refined or discarded. Differences between the algorithms could include: • Look-ahead: one vehicle or multi-vehicle • Multiple sensor inputs: – V2V data only (if available) – Acceleration from V2V and distance from radar – Sensor data fusion… • Infrastructure input (e.g. perturbations or traffic jams ahead) Possible partial system failures and intentional driver deactivation scenarios will also be considered including ways to transition from these to normal ACC operation or total system disengagement. The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
Discussion
The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
Acknowledgement and Disclaimer This material is based upon work supported by the U.S. Department of Transportation under Cooperative Agreement No. DTFH6114H00002. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the Author(s) and do not necessarily reflect the view of the U.S. Department of Transportation.
Cooperative Adaptive Cruise Control (CACC) Projects 1. CACC Pilot Study (9/14 – 3/15) –
Paper study
–
Define a common understanding of CACC
–
Create research plan
2. CACC Small-Scale Test (21 months starting 6/15) –
Integrate a (C)ACC prototype platform into vehicles
–
Establish ACC baseline performance
–
Simulate and compare algorithms and concepts
–
Perform hazard analysis The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
CACC Pilot Study Achievements • Reviewed prior and ongoing advanced research work by the USDOT and academia • Defined CACC system for: – Single and multiple vehicle look-ahead scenarios – String stability assessment
• Identified technical and safety issues and gaps • Examined a range of questions relevant to CACC • Established assumptions and constraints for CACC application • Developed recommendations and plan for further research The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
CACC Pilot Study System Definition CACC State Transition Model • An extension of ACC • Controller alternates between ACC and CACC modes without driver intervention • Must meet required communication reliability
CC – Cruise Control ACC – Adaptive Cruise Control CACC – Cooperative ACC Manual – Manual Driving The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
CACC Pilot Study Communication Issues Open questions for DSRC • V2V messages and transmission rate for CACC
– Sufficiency and effectiveness of V2V BSM – Impact of communication latency/message loss – Required minimum message transmission rate for safe and reliable operation
• Assess
– Impact of communication channel saturation on system performance – Needs for message protocol for CACC (coordinated) platoon discovery, management and safe operation – Needs for additional communication methods (e.g. unicast communication)
• Assessment of V2V communication security implementation and system performance for CACC The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
CACC Pilot Study Research Needs Additional research is needed to assess potential benefits and performance issues associated with CACC to further investigate numerous open issues including: • Benefits and limitations of the various design choices • Detailed hazard analysis for specific concepts including such factors as the effects of reduced headway and communication loss in CACC • Impact of vehicle positioning and localization performance • Use of multiple sensor data (e.g. fusion techniques) • Communication requirements and standards • Provisioning infrastructure capabilities The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
CACC Small-Scale Test
Phase 1
Phase 2
The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
CACC Small-Scale Test Exploratory Test Vehicles equipped with the reference ACC system will be characterized using the scenarios selected for exploratory evaluation. • DSRC, radar, positioning and vehicle dynamics data will be collected and analyzed • Establish baseline performance of current ACC systems • The data will also be used to parameterize the simulation environment The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
CACC Small-Scale Test Simulation A simulation environment will be set up, including:
• A microscopic traffic simulator • Evaluation metrics and processes to explore string-stability and assess the effect of various high and low level CACC control algorithms on surrounding traffic flow • A basic vehicle dynamics model for simulation purposes • Sensor models for radar sensors and for DSRC • Interfaces to dynamically control one or more of the vehicles in the simulation by the prototype CACC algorithms being developed The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
CACC Small-Scale Test Algorithm Development Multiple algorithm concepts will be developed, tested and either refined or discarded. Differences between the algorithms could include: • Look-ahead: one vehicle or multi-vehicle • Multiple sensor inputs: – V2V data only (if available) – Acceleration from V2V and distance from radar – Sensor data fusion… • Infrastructure input (e.g. perturbations or traffic jams ahead) Possible partial system failures and intentional driver deactivation scenarios will also be considered including ways to transition from these to normal ACC operation or total system disengagement. The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
Discussion
The information contained in this document is considered interim work product and is subject to revision. It is provided for informational purposes only.
