Exoskeletons have become an attractive field of research over the past decades. These devices have great potential to enhance or assist individuals by combining human intelligence and machine power. Exoskeletons are used in industry to increase the efficiency and decrease the work-related injuries. Search and rescue operations is another field in which exoskeletons are used considering the fact that in most cases time is essential for saving human lives. For example, when victims are trapped in structural collapse due to natural disasters, such as earthquakes, exoskeletons are deployed to move debris, evacuate people and transfer them to a safe place to receive medical care.
The preliminary requirements for the communication strategy of the exoskeletal device are specified. Evaluation of the most advanced communication protocols is presented along with any previous related work. EtherCAT is found to be the most suitable candidate. Virtual and physical EtherCAT network models -designed to test and validate the theoretical approach- are being introduced in this work. Moreover, a simulation study is conducted, from which the communication cycle time of the protocol is derived, providing satisfactory results that match the theoretical approach of having a minimum cycle time of 33.68us. A frame size optimisation algorithm for a novel design of EtherCAT protocol for full-body robotic exoskeleton is proposed. The theoretical and simulation approaches are validated experimentally using different kind of sensors to record and analyse the protocol performance under different conditions.
Power sources and systems that can be used to provide the needed power are also specified. The current state and challenges of the energy harvesting and wireless power transmission (WPT) technologies are evaluated. WPT is found to be the most reliable solution, since the energy harvesting technologies can only provide the energy for the on-board electronics. The simulation model of the proposed WPT system shows that the developed magnetic resonant coupling technique can transmit up to 1.8 kW of electric power with a transfer efficiency of approximately 92%.
This research presents a novel design methodology for using an array of coils in combination with the magnetic resonant coupling technique to deliver the required amount of power the exoskeleton needs to perform certain tasks. The analysis of this methodology demonstrates that by placing receiver coils at the sole of the exoskeleton and transmitter coils under the floor, the device can be charged when entering the coverage area.
