Lateral and longitudinal control algorithms for visual platooning of autonomous vehicles
Published June 12, 2000 by Society of Automotive Engineers of Korea in South Korea
This paper describes lateral and longitudinal control algorithms when vision-based autonomous vehicles form a platoon by detecting a preceding one with a machine vision system. The visual platooning is an extension of the longitudinal control in ACC, and is featured by both the lateral and longitudinal control of following vehicles. The lateral control algorithm for a following vehicle uses a target point positioned on a preceding vehicle and captured in the field of view. When the target point is appropriately positioned, a following vehicle is guided as if it chased the target.
The origin of the lateral control algorithm is an algorithm for an automated vehicle with a localization function including the dead reckoning, named the target point following algorithm. The lateral control in the visual platooning consists of the steps of target point detection, path generation, and lateral control calculation. A coefficient of a cubic curve that is defined with a target point and the current position of the following vehicle provides the steering angle. The path for the following vehicle is not necessarily the same as the preceding one, because the target can be positioned with freedom to some extent.
The longitudinal control algorithm of a vehicle is determined with a distance between a preceding vehicle and a following one. The vision system or the laser radar on the following vehicle measures the distance to the preceding vehicle. The speed control of the following vehicle is calculated with the distances measured during the previous control cycle and the present cycle, the present speed of the vehicle, the reference distances and the duration of a control cycle.
The feasibility of the algorithms is shown by simulation studies and experiments with indoor mobile robots and automated passenger cars on a test track.