Design and implementation of an Autonomous Hybrid Vehicle K. Smith, A. Corregedor, C. Murcott, B. Andrews, S. Holte, M. Furrutter, M. Evans J. Carroll * , F. Du Plessis † , and J. Meyer ‡ ‡ Head of UAV Research Group *† Senior Lecturer Department of Electrical and Electronic Engineering University of Johannesburg Johannesburg, South Africa Email: { * jcarroll, † francoisdp, ‡ johanm}@uj.ac.za Abstract—This paper outlines the design strategy for the University of Johannesburg’s (UJ’s) hybrid vehicle entry into the South African Solar Challenge (SASC) 2010. The SASC is a biennial event focused on alternative energies and showcasing various automotive technologies. The SASC is broken up into different classes; UJ entered in the Greenfleet Technology class. This paper presents the design principles and strategies used to implement a working prototype vehicle which is hybrid (propelled by multiple energy sources) and autonomous (able to operate without human assistance). Various specifications of the vehicle structure and systems (brakes and steering) are discussed in the context of these two goals. A description of physical considerations outlines the different design decisions made in order to provide the vehicle with its autonomous and hybrid capabilities; the design and implemen- tation of these systems are also described. The autonomy system allows the vehicle to follow the path of a lead vehicle. The energy management system implemented on the vehicle dynamically optimises the amount of fuel used by the internal combustion engine of the vehicle. The vehicle produced at UJ was able to participate in the SASC 2010 and win the Greenfleet Technology class. The vehicle platform has allowed the development and demonstration of hybrid energy systems and autonomous control. I. I NTRODUCTION The South African Solar Challenge (SASC) is a race taking place every two years to showcase alternative energy automobiles; the race focuses primarily on solar vehicles, but other categories of vehicles demonstrating different types of technologies are allowed to enter the race [1]. The University of Johannesburg (UJ) entered the Greenfleet Technology class with a semi-autonomous hybrid vehicle named the BAR-1. The SASC 2010 spanned 4100 km, and covered different terrains across South Africa. The BAR-1’s main objective was to increase fuel efficiency by powering a drive train using multiple energy sources. The secondary objective was to act as a research platform for autonomous technologies. This paper describes the design processes and various tech- nologies implemented on the BAR-1. The paper is structured as follows; Section II describes the platform design and considerations, Section III describes the autonomy system on board the BAR-1, Section IV describes the hybridisation of the vehicle, Section V describes the telemetry and data logging system used on BAR-1, Section VI presents the SASC 2010 results and concludes with some future research directions. II. PLATFORM DESIGN AND CONSIDERATIONS The BAR-1 can be referred to as a Multiple Input Hybrid Electric Vehicle (MIHEV), with autonomous capabilities. The energy sources for the MIHEV were as follows: an internal combustion engine (petroleum fuelled), electricity via a 1 kW hydrogen fuel cell and electricity obtained through charging. The electric potential was stored in a 48 V battery bank and delivered to a 7 kW brushed DC electric motor. The autonomous systems incorporated actuation mechatronics for drive-by-wire and sensory and processing systems for decision making. A three wheeled inverted trike architecture was chosen for the simplicity of the drive train. It should be noted that the initial considerations and design process for layout, structure and drive train were iterative and occurred in conjunction with one another. A. Layout Considerations for the layout was of primary concern during the initial design phase. The two technologies showcased (autonomy and hybridisation) were a dividing point in the project. Each technology had the following space and position considerations. Autonomy considerations: • Actuation mechatronics had to be optimally placed for mechanical coupling, i.e. near the mechanical control systems (steering rack, brake master cylinders and throttle body). • Sensory systems had to be placed so as to not hinder individual sensor performance. • Processing systems had to be located in a central position, well protected from exterior elements (water, wind and vibration). Hybridisation considerations: IEEE Africon 2011 - The Falls Resort and Conference Centre, Livingstone, Zambia, 13 - 15 September 2011 978-1-61284-993-5/11/$26.00 ©2011 IEEE