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Full-Text Articles in Mechanical Engineering
The Arched Flexure Vsa: A Compact Variable Stiffness Actuator With Large Stiffness Range, Joseph M. Schimmels, Daniel Garces
The Arched Flexure Vsa: A Compact Variable Stiffness Actuator With Large Stiffness Range, Joseph M. Schimmels, Daniel Garces
Mechanical Engineering Faculty Research and Publications
The high stiffness of conventional robots is beneficial in attaining highly accurate positioning in free space. High stiffness, however, limits a robot's ability to perform constrained manipulation. Because of the high stiffness, geometric conflict between the robot and task constraints during constrained manipulation can lead to excessive forces and task failure. Variable stiffness actuators can be used to adjust the stiffness of robot joints to allow high stiffness in unconstrained directions and low stiffness in constrained directions. Two important design criteria for variable stiffness actuation are a large range of stiffness and a compact size. A new design, the Arched …
Optimal Design Of Low Order Controllers Satisfying Sensitivity And Robustness Constraint, Mark L. Nagurka, O. Yaniv
Optimal Design Of Low Order Controllers Satisfying Sensitivity And Robustness Constraint, Mark L. Nagurka, O. Yaniv
Mechanical Engineering Faculty Research and Publications
The set of all stabilizing controllers of a given low order structure that guarantee specifications on the gain margin, phase margin and a bound on the sensitivity corresponds to a region in n-dimensional space defined by the coefficients of the controllers. For several practical criteria defined in the paper it is shown that the optimal controller lies on the surface of that region. Moreover, it is shown how to reduce that region to avoid actuator saturation during operation.