Uncrewed Systems Technology 046

37 IAC AV-21 | Dossier use to design their data flows and engine management strategies according to their preferred approach. Also, during dynamometer testing, the IAC’s engineers carried out a lot of programming through the ECU to flatten the torque curve and hence make the powertrain handle more like the electric UGVs and road vehicles most of the teams were more familiar with. “And for autonomous gear shifting, the ECU tracks the efficiency and where in the power band the engine is running, so that teams don’t have to dig in and calculate it for themselves using the CPU,” Keats says. The transmission is the IL-15’s stock six-speed sequential arrangement made by Ricardo. The Clemson University team selected gear ratios that would allow for good vehicle performance over a wide range of ground speeds, since achievable racing speeds were completely unknown when the vehicle was being designed. When a gearshift is requested, the engine controller manipulates the engine throttle plate simultaneously with a pneumatic shift solenoid to automate the process in less than half a second. And while the stock fuel systems are used, the battery system is a lithium-ion racing pack from Braille that runs through a DC-DC to supply power to the computers and sensors. “Originally we had a set-up of four lithium-ion race packs at the bottom of the chassis, but using only one keeps it simple and lightweight, and it works just fine for the electronics,” Keats says. Future plans Despite PoliMove having hit the 192.2 mph record earlier this year, the IAC anticipates the AV-21 achieving 200 mph eventually, with particular benefits expected to follow for the commercial automotive world. “Getting full autonomy to work on highways has been a major technological bottleneck for years now, but if you can achieve full autonomy at speed, you can increase the safety and efficiency with which freight and people are moved across a country,” Mitchell says. “With the software intelligence and speed our teams are unlocking, and the massive body of data we’re filtering back to our subsystem providers, we’re confident of uncovering ways to achieve commercial autonomy at 70, 80, probably 100 mph in the near future. We’re going to keep refreshing and enhancing the car each year, as it’s important that we gather and evaluate data using cutting-edge systems and technologies.” Beyond this, the IAC anticipates future versions of the AV-21 – most likely an AV-24 in 2024 at the earliest – continuing the teams’ investigations into how new automotive and powertrain technologies can be used in autonomy stacks. These include the interaction between autonomous drivers and aerodynamics, low-carbon propulsion systems and high-voltage switching systems. “A lot of that is also not very different scientifically to the new world of eVTOL UAVs, air taxis and autonomous helicopters,” Mitchell says. “We are proving out a lot of new tech at ground speeds that also need to be proven safe at high airspeeds, so it’s interesting to watch how discussions evolve between our worlds and theirs.” As of September 10 this year, the teams participating in the race have begun on-track testing, with the second official IAC race event due to take place at the Texas Motor Speedway on November 11 and the next head-to- head autonomous challenge confirmed for January 2023 at CES. Uncrewed Systems Technology | October/November 2022 AV-21 725 kg 4876 x 1930 x 1156.5 mm 2971 mm wheelbase Four-stroke engine Top speed: 192.2 mph (309.3 kph) Maximum continuous power: 473 bhp Maximum Lidar detection range: 500 m GNSS positioning accuracy: 1 cm + 1 ppm RMS Some key suppliers Chassis: Dallara Vehicle assembly, test and maintenance services: Juncos Racing Early systems integration consultation: AutonomouStuff Engine: 4 Piston Racing (remanufactured Honda Performance engine) Battery: Braille Cooling systems: PWR Lubricants: Valvoline ECU: Motec Engineering development tools: New Eagle Drive-by-wire systems: Schaeffler Paravan Anti-stall clutch: ZF Transaxle: Ricardo Tyres: Bridgestone GNSS-IMU: VectorNav Cameras: Allied Vision Technologies Lidar: Luminar Radars: Aptiv Networking systems: Cisco Local wireless infrastructure: Prism Systems Cloud computing: Microsoft Cloud hosting: AWS Main computer: dSpace Edge computing system: AdLink GPUs: Nvidia Base vehicle software: Apex.AI Connectivity software: Real-Time Innovations Simulation systems: Ansys Simulation systems: SVL Simulator Specifications