Extra Delay Time is Always Worse?—Determine Optimal Interval of Invehicle Messages in Adaptive Workload Management System using Mathematical Modeling Approaches

摘要

With an increasing usage of in-vehicle systems, drivers have to frequently perceive and respond to the messages from these in-vehicle systems. Previous studies have found that interval between the messages (arrival rate) presented to a driver becomes one of factors affecting driver workload. To reduce driver workload, researchers in adaptive workload management system (Wu et al., In Press) have found that adding extra delay time into the interval of messages can significantly reduce driver workload. However, it is unknown that whether this extra delay time added by an adaptive workload management system may or may not increase the performance time of drivers. To answer this important question, using closed-form mathematical equations, the current work quantifies human performance time (total task completion time and reaction time of each task) when there are two serial processors in the human cognitive system. The mathematical model developed in this work provides solutions of the optimal interval of messages that generate lowest workload without deteriorating drivers' performance time to respond multiple messages from in-vehicle systems. The predicted optimal interval of messages by the mathematical model was verified by a discrete-event simulation model and a behavioral experimental study. The mathematical equations developed in this study can be used in the designing of adaptive workload management system as well as other driver assistance systems.