Design of a stewart platform-inspired dexterous hand for 6-DOF within-hand manipulation

Analysis and Dimensional Synthesis of a Robotic Hand Based on the Stewart-Gough Platform

“…In these poses, one of the fingers effectively pushes the object between the other two, resulting in the ejection of the object. This kind of behavior was observed with the initial experimental prototype in [4], where the range of motion in these inter-finger directions was reduced compared to other directions. For larger values, the size of these loci is reduced, and the hand can achieve a greater percentage of the theoretical kinematic workspace.…”

“…This actuator is operated in torque control and is connected by an underactuated tendon differential to the three fingers, ensuring that they all receive equal, inward torque toward the object regardless of its position/orientation. Further information about the design of this hand can be found in [4].…”

“…(Note that in real-world linear actuators such as lead screws, ≤ 1 2 ℓ, due to practical constraints on the frames of the actuators.) In the initial hand prototype presented in [4], the spherical joint at the end of each finger was offset from the plane of the actuators by a normal distance . This was partially due to practical fabrication constraints, but also has the added benefit of increasing the clearance between the object and the finger.…”

“…First, the pose must be kinematically feasible given the geometry of the mechanism. This criterion can be easily checked through the inverse kinematics of the hand that were derived previously in [4] by treating the hand-object system as an equivalent, traditional Stewart platform. If the desired pose requires an actuator length less than ℓ − or greater than ℓ, then the pose is infeasible.…”

“…An alternative to this anthropomorphic approach is to draw inspiration from parallel robots, given their high dexterity and mechanical simplicity. In our previous work, we proposed a novel hand design based on the Stewart-Gough platform that effectively transferred these desirable properties from the realm of parallel robotics into a dexterous hand framework [4]. This hand consisted of six prismatic joints arranged into three fingers ( Fig.…”