Human Body Simulation Within a Hybrid Operating Method for a Safe and Efficient Human-Robot Collaboration

The planning and integration of production systems with a direct human-robot collaboration (HRC) is still associated with various technical challenges. This applies especially to the realization of the operation methods speed and separation monitoring (SSM) as well as power and force limiting (PFL). Due to the limited consideration of the human motion behaviour, the required dynamic separation distance in SSM is frequently oversized in practice. The main consequences are wasted space as well as cycle time and performance losses within the corresponding HRC application. In PFL a physical contact between the operator and robot is permissible, taking into account specified biomechanical thresholds. However, there is still a lack of suitable use-cases since the maximum permissible speeds are on a very low level. Moreover some thresholds regarding the transient contact case are still non-applicable for critical body areas (e.g. temple, middle of forehead). The study of this paper is related to a kinematic state determination of the human operator within a new hybrid collaborative operation. In this method the SSM type is extended regarding the description of the operator and coupled with the two-body contact model of the PFL. Using a planning and simulation tool for HRC, the kinematic states of different body regions are derived from an integrated and parameterized digital human model. Afterwards, these body regions are mapped to the characteristic body areas of the ISO/TS 15066, whereby the resulting information will be applied in an adaptive robot speed control. The performance of the presented concept will be evaluated using an exemplary simulated HRC scenario.

Development and Control of Power-Assisted Lumbar Suit Based on Upper-Body Acceleration

In this study, we propose a method to estimate the assistive timing requirements for a power-assisted lumbar suit based on upper-body acceleration. Our developed power-assisted suit combines of springs, wires, and an electrical motor to provide efficient assistance. The assistive torque provided by the suit was determined based on a digital human model. The assistive timing using the electrical motor was calculated from the upper-body acceleration measured using two internal accelerometers. Herein, we present the experimental results based on the myoelectricity of a muscle during lifting motions involving three participants acting as caregivers to elderly patients.

Modeling and experimental verification of rapid inversion model of living body based on FEM model

OBJECTIVE: This study aims to verify the practicability and accuracy of a finite element model (FEM) built using digital human model construction and to apply the model to actual explosion impact inversion. METHOD: We proposed a simplified rapid inversion model using digital human modeling. In modeling, cell mesh generation was performed using preprocessing software (ANSYS ICEM CFD), measured organism data were used as the corresponding geometrical parameters of all specified parts, and material characteristics parameters were set according to tissue characteristics. FEM construction was completed in the ANSYS LS-DYNA software and verified by an equivalent experiment. RESULTS: The rapid inversion FEM was built by employing digital human model construction. Through analysis, it was concluded that the calculation result was practically consistent with the experimental result. CONCLUSIONS: By creating the digital human model based on a CT dataset, the FEM inversion model of an approximately actual material environment can be rebuilt, and the model can be used to study human thorax injury characteristics.