Hitachi Astemo (Chiyoda-ku, Tokyo) developed an algorithm called "Dynamics Planning" as a highly accurate trajectory planning technology for autonomous driving electronic control units (AD ECU). This algorithm ensures a comfortable cabin experience by suppressing unpleasant shaking and acceleration at the front, back, left, and right during autonomous driving with advanced driving-support technology.
When developing autonomous driving technology, it is necessary to build a system that allows the vehicle to drive safely to its destination. However, as autonomous driving technologies increase in complexity, the comfort of the passenger compartment becomes increasingly important as the driver is expected to engage in activities other than driving. For example, a skilled driver strives to keep the passenger compartment comfortable by following a gentle trajectory that utilizes the lane width effectively when turning, and mitigating the unpleasant swaying at the front, back, left, and right of the car by controlling the speed appropriately according to the trajectory. However, with existing advanced driver-assistance technology, since the vehicle travels at a constant speed and closer to the center of the lane, unpleasant left-right shaking and acceleration may occur. Therefore, the comfort in the passenger compartment is impaired, and motion sickness can easily occur.
In response to this need, Hitachi Astemo has developed Dynamics Planning, an algorithm that controls the trajectory and speed during autonomous driving with advanced driver-assistance technology, while keeping the interior of the vehicle comfortable like a skilled driver would. This is a technology that uses external recognition sensors such as cameras, map information from the map position unit (MPU), and traffic information from future infrastructure provides data regarding the travelable area in front of the vehicle to the AD ECU. It is possible to plan a trajectory that can suppress the acceleration exerted on the vehicle as well as any changes in acceleration. The algorithm can also ensure a speed at which acceleration is minimal, by utilizing the width of the travelable area effectively and following a very gentle trajectory when turning. The highlight of Dynamics Planning is that it enables simple track planning without using vehicle specifications, as the vehicle specifications and disturbance factors are handled by the original vehicle control technology.
Conventionally, when planning such a route, complicated calculations must be performed using vehicle specifications such as the weight and length. This necessitates an AD ECU with high computing power; moreover, comfort may be compromised if an unintended disturbance is caused by factors such as strong winds or unevenness road surfaces. However, an autonomous vehicle travelling on the target route determined by Dynamics Planning can ensure comfort by suppressing unpleasant shaking and acceleration in the forward-backward and left-right directions, just like a skilled driver does. Hitachi Astemo announced the development of Dynamics Planning at the Spring Convention hosted by the Society of Automotive Engineers of Japan, which was held online from May 26th to 28th.
This article has been translated by JST with permission from The Science News Ltd.(https://sci-news.co.jp/). Unauthorized reproduction of the article and photographs is prohibited.