BRIDGE - Development of a motor-joint unit with variable stiffness

In this document, the activities carried out within the Task2.6 "Development of a motor-joint unit with variable stiffness" of the Bridge project are reported. The whole activity led to the development of two novel variable stiffness actuators, namely RotWWC-VSA and CS-VSA, respectively, the second one developed to overcome the limitations and the downsides of the first one. During the development of the RotWWC-VSA, some aspects where hardly underestimated and, in the middle of the project, the decision to develop a completely new actuator was taken. The common aim of the two actuators was to develop a technology enabling the patient to interact smoothly with the exoskeleton, based on the principle at the basis of Variable Stiffness Actuators. Requirements, specifications and design guidelines are presented in Chapter 2, where the rationale behind the choice of adopting a variable-stiffness architecture is presented. The two actuators are presented in Chapters 3 (RotWWC-VSA) and 4 (CS-VSA), describing mechanical design, control, electronics, and the prototypes manufactured. Conclusions about the developed technologies are drawn in Chapter 5, highlighting the advantages and the peculiarities of the CS-VSA.