The research work in SmartANKLE is divided in three interconnected clusters:
- Needs analysis and mechanical design. This cluster will oversee the definition of the biomechanical and stakeholder needs for the SmartANKLE platform, together with the mechanical design of its components different actuation configurations. In this cluster, an in-depth analysis of needs will be carried out to understand what the biomechanical, clinical and users’ requirements for a SMAFO are depending on the application, including: (a) the biomechanics of the intended application (e.g. sport training vs. augmentation vs. assistance in stroke patients); (b) the torque requirements and optimal application points for each application; (c) the intended use from all potential users (both end users and sport/orthopedic clinicians), including which assistance/training scenarios are more important to them; (d) other stakeholders needs, including market related aspects; (e) aesthetical considerations. The cluster will develop the mechanical design of the modular components of SmartANKLE orthosis.
- Actuation. This cluster will develop the actuation technology for the SmartANKLE orthosis. The technology that will be investigated will be a clutch-based compliant actuator design. The clutched design can be optimized in terms of energy efficiency by exploiting the passive behavior of the compliant element. This however raises new research questions in terms of control and dynamics of the actuation system. As the addition of a clutch might increase the weight of the ankle orthosis, we will explore the possibility of displacing a part of the mass of the actuator (motor/transmission/clutch) to more proximal locations on the human body. Part of the research work will consist of solving existing problems in the so-called mid-level control of the active wearable device. This activity will, on one side, be focused on several of the specific problems that arise with the implementation of clutches and remote actuation, but also provide solutions that can be generalized for any SmartANKLE configuration.
- Sensors and control. This cluster will develop the sensor array for the SmartANKLE platform and a user-in-the-loop control approach which will allow for seamless interaction with the system in both volitional and autonomous fashion. The sensor array and the control system will be both integrated in a lightweight embedded sensing and control unit. The sensor array will include sensors measuring surface electromyography (EMG), kinematics (acceleration, joint angle), and kinetics (forces, torques) around the ankle joint, to provide a full neuromechanical characterization of ankle behaviour during different tasks. The volitional controller will be based on a blended sensory fusion model that will adaptively estimate the elicited joint torque
