A Novel Velocity Planner for Autonomous Vehicle Considering Human Driver’s Habits 2020-01-0133
In automatic driving application, the velocity planner can be considered as a key and critical factor to ensure the comfort performance. One of the most important tasks of the velocity planner is to simulate the velocity characteristics of human drivers. In this paper, two Driver In-the-Loop (DIL) experiments are designed to explain velocity characteristics of human drivers. In the first experiment, static obstacles are placed on both sides of the straight road to shorten the cross range that vehicles can driver across. Moreover, different cross ranges are set to study the influence of the steering wheel error on the velocity. In the second experiment, velocity characteristics of human drivers are investigated under the condition of different road widths and curvatures in a U-shaped turning road contour. In both DIL tests, different driving styles are analyzed through the operation result of several drivers, including throttle, braking, and steering. On this basis, a novel velocity planner is proposed based on DIL experimental results. Firstly, a target velocity in sampling terminal point is calculated. The calculation of the velocity is based on two indicators--the degree of visual restriction, and the driver's driving and operating ability. The former is related to the uncertainty of the environment, and the driver's driving and operating ability refers to the ability of the driver to maintain the driveway as well as the control ability of the vehicle stability. Subsequently, the smooth velocity profiles that connect the initial point and the sampling terminal point are generated based on the convex optimization. Finally, the simulation results show that this novel velocity planner possesses good human-like performance, considering the human-vehicle-road coordination. This study is useful to customize velocity planning for autonomous vehicle so as to improve the acceptability of the specific human driver.