Design and real-world evaluation of three types of haptic lane-keeping support systems for truck drivers

Abstract

Designing lane-keeping assistance (LKA) systems that are both effective and well-liked by drivers is a highly challenging process, that is not well understood. This is illustrated by a wide variety of market releases of LKA systems, and a large body of literature illustrating different designs and various evaluation methodologies that are often performed in driving simulators. As a result, it is unclear how design choices impact driver steering behaviour and acceptance, and extrapolate this to real-world driving where driver distraction is often a reality. This study presents a detailed evaluation methodology to compare three haptic LKA designs in a single real-world truck driving study. These designs are constructed based on two haptic LKA approaches found in literature; continuous support and bandwidth support. It is hypothesized that continuous support is favored over bandwidth support but that both LKA approaches are effective and well-liked when implemented in real-life and show to be particularly effective for distracted drivers. Two of the evaluated systems were
triggered to generate haptic torques only when the predicted lateral error exceeded a bandwidth of 0.4 m: a single-bandwidth system (SB); that shuts off the guidance when the predicted lateral error returned within the bandwidth, and a double bandwidth system (DB); that shuts off the guidance when a second inner bandwidth (close to lane center) is reached [38]. The third evaluated system generated continuous haptic torques towards the lane center: a continuous double bandwidth system (CDB). Sixteen participants drove four trials on a private test-circuit; one trial without and three trials with haptic support. For each support system, participants drove
both a distracted and a non-distracted condition. The results show that compared to manual control, all three support systems provided equal benefits in terms of accuracy and prevention of large lateral errors (>0.7m). When a lane departure did occur both DB and CDB support systems showed shorter lane departure times with smaller lateral errors compared to manual driving. The DB and CDB support systems showed high driver acceptance and reduced large swerving behaviour that was observed during distracted driving. All three support systems however lacked effectiveness and driver acceptance during curves. Ultimately the CDB support system was the overall
preferred haptic LKA design. This study shows the potential for DB and CDB support to be used in real-life, however higher driver satisfaction can be achieved when the support systems are able to cope with humans’ driving behaviour during curves.