Standard Practice for Utilizing Digital Human Modeling in Exoskeleton Design and Application

5.1 This practice guides the user through a selection of digital human modeling methods, various modeling focuses, and available outcomes for use in evaluating the performance of existing exoskeletons and predicting/simulating the performance of exoskeleton concept designs. Fig. 1 shows a flow chart for developing a digital human-exoskeleton model for a different purpose. Overall, there are two major usages of DHM in the application of human-exoskeleton interaction. First, DHM can be used to simulate an expected task, a specific expected exoskeleton design, and predict expected workloads on users. The results from this type of DHM can be used to virtually design a new exoskeleton device or design/evaluate new human-exoskeleton interaction scenarios. The second typical use of DHM is for the evaluation of real human-exoskeleton interactive tasks. Data required to build such DHM are mainly from real data collection where users’ anthropometry, motion, external forces, as well as kinematics of the exo devices are collected from a simulated task in a laboratory environment or a real task in the field. Further details can be found in Section 7.

5.2 The benefits of using DHM in understanding the teaming operation between users and exoskeletons mainly include: (1) reduce time and costs of the equipment development cycle, no real prototype is needed, and all the design/redesign procedures can be completed virtually and efficiently with good flexibility of the design procedure; (2) avoid potential risks due to uncertainty while exploring various exoskeleton design ideas and human-exoskeleton interaction scenarios; (3) DHM can also provide an offline estimation of internal loads placed on users during real human-exoskeleton interaction, identifying potential risks associated with posture, loads, and other human-exoskeleton interaction; and (4) DHM can be used as a surveillance solution to provide real-time workloads estimations and risks identification. The detailed model components and modeling procedure are explained in Sections 6 and 7.

5.3 This practice is expected to provide guidance for many, although not all, estimations and evaluations of human-exoskeleton interaction activities. The method described in this practice can be used as a basic method of DHM or as guidance for developing additional and advanced DHM of human-exoskeleton interaction.