Design of a Variable Stiffness Actuator Based on Flexures

Abstract

Variable stiffness actuators can be used in order to achieve a suitable trade-off between performance and safety in robotic devices for physical human–robot interaction. With the aim of improving the compactness and the flexibility of existing mechanical solutions, a variable stiffness actuator based on the use of flexures is investigated. The proposed concept allows the implementation of a desired stiffness profile and range. In particular, this paper reports a procedure for the synthesis of a fully compliant mechanism used as a nonlinear transmission element, together with its experimental characterization. Finally, a preliminary prototype of the overall joint is depicted.

Design and testing of a novel multi-stroke micropositioning system with variable resolutions

“…Hence, a low-speed motion is expected for the smaller stroke. In addition, the condition as shown in (14) indicates that the fine and coarse positioning are achieved in the first and last strokes, respectively. This seems contradict the requirement of a typical multi-stroke application, where the coarse positioning is realized in the first stroke and the fine positioning is obtained in the last stroke.…”

“…In the literature, the variable stiffness concept has been exploited to develop devices with desired stiffness profiles dedicated to robot-environment interaction applications. [13][14][15] In addition, the idea of variable stiffness has been explored to design constant-force mechanisms, 16 bistable/tristable compliant mechanisms, 17 and statically balanced mechanisms 18 for macro-and micro-scale applications.…”

A miniaturized optical force sensor for tendon-driven mechatronic systems: Design and experimental evaluation

“…Compliant mechanisms are often used for the implementation of linear actuators using smart materials [28,29], for the development of compliant transmission system [30] or as displacement/ force magnifiers [31,32]. With respect to previous solutions, the particular characteristic of the proposed sensor is that it can be mounted in any position along the tendon and it does not need to be designed as a structural element, i.e.…”

Wave mixing in coupled phononic crystals via a variable stiffness mechanism

“…Traditionally, variable stiffness mechanisms have been widely used for engineering applications, such as vibration isolation systems (VIS) [29,30], robotics [31,32], and rehabilitation devices [33]. Only recently have researchers adopted variable stiffness mechanisms for the manipulations of mechanical waves in PCs.…”