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Full-Text Articles in 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 …
Therapeutic Potential Of Haptic Theradrive: An Affordable Robot/Computer System For Motivating Stroke Rehabilitation, Andrew Theriualt, Mark L. Nagurka, Michelle J. Johnson
Therapeutic Potential Of Haptic Theradrive: An Affordable Robot/Computer System For Motivating Stroke Rehabilitation, Andrew Theriualt, Mark L. Nagurka, Michelle J. Johnson
Mechanical Engineering Faculty Research and Publications
There is a need for increased opportunities for effective neurorehabilitation services for stroke survivors outside the hospital environment. Efforts to develop low-cost robot/computer therapy solutions able to be deployed in home and community rehabilitation settings have been growing. Our long-term goal is to develop a very low-cost system for stroke rehabilitation that can use commercial gaming technology and support rehabilitation with stroke survivors at all functioning levels. This paper reports the results of experiments comparing the old and new TheraDrive systems in terms of ability to assist/resist subjects and the root-mean-square (RMS) trajectory tracking error. Data demonstrate that the new …
Spatial Admittance Selection Conditions For Frictionless Force-Guided Assembly Of Polyhedral Parts In Single Principal Contact, Shuguang Huang, Joseph M. Schimmels
Spatial Admittance Selection Conditions For Frictionless Force-Guided Assembly Of Polyhedral Parts In Single Principal Contact, Shuguang Huang, Joseph M. Schimmels
Mechanical Engineering Faculty Research and Publications
By judiciously selecting the admittance of a manipulator, the forces of contact that occur during assembly can be used to guide the parts to proper positioning. This paper identifies conditions for selecting the appropriate spatial admittance to achieve reliable force-guided assembly of polyhedral parts for cases in which a single feature (vertex, edge, or face) of one part contacts a single feature of the other, i.e., all single principal contact cases. These conditions ensure that the motion that results from frictionless contact always instantaneously reduces part misalignment. We show that, for bounded misalignments, if an admittance satisfies the misalignment-reducing conditions …
Efficient Contact State Graph Generation For Assembly Applications, Feng Pan, Joseph M. Schimmels
Efficient Contact State Graph Generation For Assembly Applications, Feng Pan, Joseph M. Schimmels
Mechanical Engineering Faculty Research and Publications
An important aspect in the design of many automated assembly strategies is the ability to automatically generate the set of contact states that may occur during an assembly task. In this paper, we present an efficient means of constructing the set of all geometrically feasible contact states that may occur within a bounded set of misalignments (bounds determined by robot inaccuracy). This set is stored as a graph, referred to as an Assembly Contact State Graph (ACSG), which indicates neighbor relationships between feasible states. An ACSG is constructed without user intervention in two stages. In the first stage, all hypothetical …