Continuous Haptic Information and Platform Stabilization in Target Tracking

摘要

The present study was conducted to gain insight in the effects of different formsof continuous haptic information (CHI) to operator performance of an unmanned platform equipped with a camera-monitor system. In a simulator experiment, subjects had to track a moving target keeping a simulated disturbed platform as well as possible straight above a moving target. While performing this tracking task, haptic information was provided concerning translations of the platform (and thereby of camera). Two independent control variables were manipulated between-subjects (four control conditions). These factors were: presence or absence of CHI and of (automated) stabilization of the platform. Each of the four groups consisted of 14 subjects. Three other factors were varied within-subjects, i.e., image degradation by four different image update rates, motor taskload through the amount of target motion, and visual taskload by the presence or absence of an extra visual attention-task. During the experiment subjects were seated in front of a monitor in a closed room. This screen was used for visual information presentation. The supplementary haptic information was generated by movements of a so-called active joystick which at the same time was used for steering the camera by 'force control'. Analysis of the tracking errors shows that CHI as well as automated platform stabilization substantially reduced tracking error. These effects were not additive as the combined effects of CHI and stabilization were not larger than the separate effects. Whereas the effect of stabilization diminished (but remained significant) with increasing update rate, the effects of CHI and update rate were additive. With increasing motor or visual taskload, as a consequence of an extra visual task or increased target motion, the stabilization effect increased.