Design and implementation of adaptive cruise control system for the TU/e solar powered electric car

The technical report presents the design and implementation of Adaptive Cruise Control. (ACC) system for the “Stella Lux” solar powered electric car, which was built by Solar Team Eindhoven and won the World Solar Challenge in Australia in 2015. Initially, an over-view of the context of the project is given, including information about the people for whom the project was performed and how it is related to their general intentions and goals. The project goals, objectives and delimitations were then analyzed, followed by the definition of the combined V-model and CAFCR system engineering approach and the hardware and software tools used for carrying out and completing successfully this project. As a next step, a stakeholder analysis was made and a context diagram was created for the definition of the project scope. In addition, a use case approach was applied for the specification and elicita-tion of the functional and non-functional system requirements. Subsequently, the functional architecture of the Adaptive Cruise Control system was proposed, where different hardware and software components were identified. A thorough sensor technology analysis was per-formed, which concluded with the selection of the most suitable sensor for the implementa-tion of the system in the “Stella Lux” and other future solar cars which will be built by next generations of Solar Team Eindhoven. The sensor selection was based on several criteria, such as range, Field Of View (FOV), weight, place of installation and energy consumption, so that not only the ACC system can function properly but also the performance of the solar vehicle can remain almost unaffected. The ACC controller design consists of two major software components, namely the Supervisory controller and the Governor. The Supervisory controller was designed based on the defined system functional requirements, using a heuristic approach for the design of state flow charts. The Governor was designed using a combined distance/speed control approach in cascade structure. The ACC controller was modelled in MATLAB/Simulink and State flow software tool and built in a HP laptop, which was used as Electronic Control Unit (ECU) during the implementation of the system in the solar car. A radar object filtering algorithm was also designed and implemented for an appropriate filtering of the raw data coming from the selected radar sensor and for the detection of the relevant to the system functionality lead vehicle that should be followed. The system was verified and validated by creating test cases which were run both by simulation and Hardware-In-the-Loop testing. The Verification and Validation phase was carried out to assess whether the ACC functionality meets the defined functional and non-functional requirements, which include also the customer wishes. Finally, for the successful completion of this project, a proper project management process was followed, which includes the project planning, the communication strategy applied among the project stakeholders and the definition of a risk management strategy for mitigation of potential project risks. It was concluded that the proposed Adaptive Cruise Control (ACC) system design can provide an important contribution to the future solar powered electric cars that the next generations of Solar Team Eindhoven will built, since it can be used while driving on highway roads in order to improve driver comfort and safety, which are two key parameters for winning the World Solar Challenge. Solar Team Eindhoven will be also able to show in the next challenge that a “smart”, energy efficient and environmentally friendly solar car could be the ideal future vehicle for everybody, obtaining a significant share in the automotive market. In addition, it was concluded that the operation of the ACC system with the regenerative braking functionality can decrease the energy consumption of the solar car and thus increase its range compared to any conventional ACC system which uses Electronic Braking System (EBS) and does not recover any of the vehicle’s kinetic energy during braking.