Fig 4 - uploaded by Julio Fajardo
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Torque τ applied on the MCP, PIP and DIP joints' axes (τ 1 , τ 2 and τ 3 , correspondingly).

Torque τ applied on the MCP, PIP and DIP joints' axes (τ 1 , τ 2 and τ 3 , correspondingly).

Source publication
Conference Paper
Full-text available
Controlling different characteristics like force, speed and position is a relevant aspect in assistive robotics, because their interaction with diverse, common, everyday objects is divergent. Usual approaches to solve this issue involve the implementation of sensors; however, the unnecessary use of such devices increases the prosthetics’ prices in...

Contexts in source publication

Context 1
... utilizing the aforementioned results forˆqforˆ forˆq, one can determine the resulting torque on each of the joints' axes using the Eq. (6). This can be visualized in Fig. 4, where the torques exerted on the MCP, PIP and DIP joints correspond to τ 1 , τ 2 and τ 3 , ...
Context 2
... opened or grasping an object, rather than a precise position and orientation of the fingertips, the estimation error obtained is sufficient for the apt fulfillment of ADLs. Additionally, this data can be used to determine the kinematics and dynamics of each finger of the assistive device by estimating its generalized coordinates, as shown in Figs. 3 and 4, and employ this information in robust torque and impedance controllers. Moreover, such a model enables its implementation in an MCU, allowing for a more compact and affordable option to install on ...
Context 3
... observing the comportment of the torques' behaviour, shown in Fig. 4, one can trace the finger's movements as it flexes and extends. The first main peak indicates when the motor starts to coil the string, leading the motor, the elastic and the joints to have to overcome the static friction coefficient to start mobilizing; therefore a higher tensile force (and torque) has to be exerted (Fig. 5). ...
Context 4
... to have to overcome the static friction coefficient to start mobilizing; therefore a higher tensile force (and torque) has to be exerted (Fig. 5). Additionally, the second peak is a negative one, as the actuator breaks, which causes it to spin in the opposite direction; similarly, with the extension process. Other relevant aspects to note on Fig. 4 are the offsets in torque and the fact that their derivatives and peaks increase in magnitude as they are closer to the metacarpus. The first one depends on the gravitational energy impacting each joint, while the latter is consequence of moving a larger lever as the joints are farther from the fingertip. In addition to that, a change ...

Citations

Article
Full-text available
The complexity of the user interfaces and the operating modes present in numerous assistive devices, such as intelligent prostheses, influence patients to shed them from their daily living activities. A methodology to evaluate how diverse aspects impact the workload evoked when using an upper-limb bionic prosthesis for unilateral transradial amputees is proposed and thus able to determine how user-friendly an interface is. The evaluation process consists of adapting the same 3D-printed terminal device to the different user-prosthesis-interface schemes to facilitate running the tests and avoid any possible bias. Moreover, a study comparing the results gathered by both limb-impaired and healthy subjects was carried out to contrast the subjective opinions of both types of volunteers and determines if their reactions have a significant discrepancy, as done in several other studies.