Misalignment Compensation for Full Human-Exoskeleton Kinematic Compatibility: State of the Art and Evaluation

The use of exoskeletons by the elderly, disabled people, heavy labor workers, and soldiers can have great social and economic benefit. However, limitations in usability are impeding the widespread adoption of exoskeletal devices. Kinematic compatibility, comfort, volume, mass, simplicity, expandability, and the ability to transmit forces, relative angles between the exoskeleton and the human, and the donning and doffing procedure need to be considered. Over the last decades, a large number of exoskeletons have been developed, to assert kinematic compatibility and compensate for misalignment. To such a degree, that it has become difficult to keep an overview of the different strategies. Therefore, this review article presents an extensive overview of different misalignment compensation strategies existing in the literature. Further, these strategies are organized in nine categories, evaluated and discussed around the exoskeleton's application domain and its specific requirements and needs.