The Oxford University’s Mobile Robotics Group (MRG) RobotCar is a modified Nissan LEAF. Lasers and cameras are subtly mounted around the vehicle and taking up some of the boot space is a computer which performs all the calculations necessary to plan, control speed and avoid obstacles. Externally it’s hard to tell this car apart from any other on the road. It is designed to take over driving while traveling on frequently used routes.
RobotCar constantly monitors the road ahead to look for pedestrians, cars or anything that could pose a danger. If an obstacle is detected the vehicle comes to a controlled stop and waits until the obstacle has moved out of the way. Once clear the car simply accelerates and continues its journey.
There are three computers onboard. The iPad, the LLC (Low Level Controller) and the MVC (Main Vehicle Computer). The iPad runs the user interface and demands constant attention from the LLC. If any of these computers disagree the driver will not be able to start autonomous driving. If at any point there is a problem when the car is in control the human driver is prompted to take control, if they fail to do so the car is automatically brought to a stop.
The sensors and computers build up a three-dimensional map of the route. This is augmented by semantic information such as the location and type of road markings, traffic signs, traffic lights and lane information, as well as aerial images. Since such things can change, the system can also access the internet for updates. Only when the system has enough data and has been trained enough will it offer to drive the car.
They have modified the base Nissan LEAF systems to allow complete fly-by-wire control. Everything from the steering to the indicators can be manipulated by the main vehicle computer in the boot. RobotCar senses the world in two main ways. The first uses a pair of stereo cameras to assess the road and navigate, much like a human driver’s eyes. The second is a little different and uses several lasers mounted around the vehicle. These sensors assess the 3D structure of world and also improve performance at night.
The MRG team sees an immediate future in production cars modified for autonomous driving only part of the time on frequently driven routes. They estimate that the cost of the system can be brought down from its current £5,000 ($7700) to only £100 (US$155).