机械臂遥操作任务过程脑力负荷研究

Study on Mental Workload in Manipulator Teleoperation Mission

脑力负荷是影响机械臂遥操作绩效的重要因素,通过提取机械臂遥操作过程的自发脑电功率谱特征以及非线性动力学特征,结合机械臂遥操作的三阶段操作理论,分析了操作过程脑力负荷变化规律,以及各阶段的主要认知负荷来源。实验表明:自发脑电功率谱指标能有效评估遥操作过程被试的脑力负荷水平,非线性指标能有效评估思维活动水平。在遥操作中,脑电功率谱能量逐渐向高频段转移,脑力负荷水平逐渐升高;前两阶段的非线性动力学特征值显著高于最后阶段,在第二阶段达到最大,与被试的思维活动强度变化规律相同。前两阶段被试脑力负荷主要来源于空间认知,第三阶段负荷主要来源于距离和角度偏差认知及任务压力。根据遥操作任务过程的脑力负荷变化规律及负荷的主要来源针对性提供信息补偿,完善任务设计,可降低航天员在各个阶段的脑力负荷水平,对保障遥操作任务的完成有一定指导意义。

Mental workload is an important factor affecting the performance of manipulator teleoperation. By extracting the power spectrum and the nonlinear dynamics characteristics of electroencephalogram（ EEG）,the mental workload variation and the main cognitive load at various stages in the operation were analyzed on the basis of the three stages operation theory in teleoperation. The results showed that EEG power spectrum could be used to evaluate the mental workload in teleoperation effectively,and the nonlinear dynamics index could be used to evaluate the thinking activity level effectively. In teleoperation,EEG power spectrum energy shifted to the high frequency band gradually with the increase of the mental workload; the nonlinear dynamics characteristic values of the first two stages were significantly higher than that of the final stages,and reached the maximum in the second stage,so did the variation of the subjects＇ thinking activity intensity. The mental workloads of the first two stages were mainly derived from the spatial cognition,and the mental workload of the third stage was mainly derived from the distance and angle deviation cognition and working pressure. According to the mental workload variation and the main source of workload in teleoperation,the compensative information could be provided and the task design could be improved to reduce the mental workload of astronauts in various stages. It is of reference value for the completion of teleoperation mission.