We evaluated our optimized stress monitoring system, consisting of pressure insoles and inertial sensors, by comparing its performance to a laboratory grade system in a mock-up of realistic working conditions. Sensor outcomes and resultant low back load measures were compared between systems. The system was found to meet standards in accordance with the previously defined requirements.
We organized a workshop titled Exoskeleton design through optimization and adaptive control at the IEEE RAS International Conference on Humanoid Robots (HUMANOIDS 2017) that were held in Birmingham, UK during November 15-17, 2017.
The aim of the workshop was to bridge the gap between optimality principles and adaptive control to create a new generation of exoskeletons that would efficiently and unobtrusively operate on the human body. The main theme was how to leverage exoskeleton research with novel adaptive control concepts and optimization methods in order to advance it into a key technology.
In recent work UHEI led efforts towards the modeling of a passive spinal exoskeleton, and simulating the interaction between the human user and the exoskeleton (Millard et al. 2017, Manns et al. 2017, Harant et al. 2017). These results build upon earlier contributions of a dynamic whole body human model which is used as a basis for the exoskeleton design. We use a combined model of a human and a parametrized exoskeleton and setup optimal control problems to identify exoskeleton spring characteristics or motor torques for lifting motions. The motions simulated are either fitted to recorded data (collaboration with S2P and VUA), or generated as the solution of a minimization function. We also compute the forces and torques transmitted between the human and the exoskeleton. These are important first measures that will help support the exoskeleton and human-exoskeleton-interface design process.
In December 2016 we formalized the conceptual design based on the specifications from the requirements workshop. Over the last months, OBG and VUA had an intensive exchange about the used biomechanical models to consider the latest scientific approaches for the monitoring system. We now started with the implementation of the monitoring system.
The team at UHEI developed a dynamic model of the human body. Together with the team at VUA we collected the movement and ground reaction forces of a human subject performing a series of everyday activities. We later used this data to build a multi-body dynamic model of the subject that included detailed models of several muscle groups. These are necessary so that the strength of the model varies with posture and the speed of movement just as it does in real humans.
Based on the meeting between JSI, UHEI and VUA in Amsterdam in October 2016 we formulated a high-level control architecture of the spinal exoskeleton. The architecture will be implemented as a multi-layered system with reactive and model based controllers to meet the necessary ergonomic requirements for LBP prevention and treatment.
We co-organized two workshops at the 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2016) that were held in Daejeon, Korea during October 9-14, 2016:
Based on the Requirements Workshop in Duderstadt, six core requirements of the SPEXOR technology were specified to accommodate considerations regarding the etiology of low-back pain and the biomechanics of the human spine during manual materials handling tasks.