Human response delay estimation and monitoring using gamma distribution analysis

The aim of this paper is to estimate and monitor the human response delay in manual control tasks. A probability distribution analysis is applied on the response delay, based on experimental data collected from human subjects controlling a dynamic system and responding to visually perceived errors via joystick or steering wheel. The distribution analysis includes firstly a sliding segment method, to extract the delay time for each slice of data. Then, probability distributions of the delay time are fitted by using a bootstrap based goodness-of-fit test. For both manual-control cases, with a joystick and a steering wheel respectively, the experimental data can be explained reasonably by a Gamma distribution. Consequently, the Gamma distribution parameters for different human subjects are compared. Based on these findings, an online monitoring method of the level of attention in the human-operator - or applied workload - is proposed, which could be of interest for relevant shared-control applications.