PROSTHETIC HAND
Overview
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As the perspective of technology tends to make human life easier and safer a vital contribution still remains in the field of upper limb prosthetics. In view of these aspects, a 6DOF robotic hand was developed at IVLABS as a cost-efficient replacement to existing Prosthetic hands yet retaining the functionality of human hand.
Working Principle
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Each finger has a individual motor to be allowed to move independently replicating HUMAN HAND.The fingers are under-actuated with their Actuation driven by high torque mini servo actuators through tendons as non-linear parameters.The thumb also has roll motion at its base as 6th degree of freedom for the system.TSOP1738 receivers are simple proximity sensors that triggers on receiving an infrared wave transmitted with suitable luminous intensity.Both Transmitters and receivers are placed at fingertips and as an object is sensed closer than 1.5 cm the actuators get triggered,hence the number of fingers to be used for gripping are decided without using EEG/EMG techniques.
Electronic Controls
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The sub-controller circuit is based on the ARM CORTEX M4-32 bit processor acting as an link between the sensors and actuators. Inclusive of the power circuitary for sensors,actuators and output Leds. Also the protection circuit from external SMPS power supply.
Mechanical Design
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Designing and Modelling of system parameters like fingers and base palm were done in Solidworks. Performance of hand was evaluated based on the simulations for each fingers. Based on these aspects experiments and iterations were performed and design was finalized. The complete hand structure was fabricated using 3D printing using PET plastic material.
Features
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ROBUST BUILD The material used is light weight having good strength with a stable mechanical
structure.
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COST EFFICIENT Manufacturing of complex mechanical design made easy using 3D printing and thus
lower in cost.
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CUSTOMISABLE DESIGN Customisable design made using interchangeable parts.
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OBJECT ORIENTED ​Power grasp, Column grasp, Tripod grasp, Precision closed grasp, Precision
GRIPPING TASKS open grasp, Hook grasp, Trigger grasp, Pinch relaxed hand.
VIRTUAL VISION ​ Complex EEG, EMG features are provided through the proximity vision sensors at the
fingertips.