KTHand is a robot hand designed within a doctoral thesis by Johan Tegin. KTHand is meant to be a simple construction, able to be produced for a low cost but still be functional thanks to feedback from tactile and position sensors. The mechanical construction of KTHand is based on three identical fingers, corresponding index finger, middle finger, and a thumb. Each finger consists of three movable links, called phalanges, connected by a leaf spring on the top. For the force actuation, a fishing line acting as a tendon is running through ducts in the phalanges. Each tendon is powered by a direct current motor in the hand, and this gives a finger three degrees of freedom (D.O.F.) with only one actuator, i.e. an under-actuated finger. To evaluate KTHand – simulations in the open-source software GraspIt! have been carried out. These simulations have been more or less successful, and a wish for simulation in another program has arisen. MSC ADAMS is a widely used and verified commercial program which is used for setting up advanced physical multibody simulations. ADAMS is fairly untested for the purpose of simulating robot hands and that is why it is of interest to see whether it is possible to successfully simulate the grasp dynamics of a robot hand, which is the topic for this thesis.As a starting point for the model design in ADAMS, a previously developed CAD model has been used since ADAMS provides the ability to import CAD files. To decrease the level of complexity, a number of simplifications have been done to the CAD model – unnecessary geometry such as screws and screw holes have been removed and curved lines in the geometry of the hand have been replaced by straight lines.After the simplified model was imported in ADAMS – joints, springs and contact conditions have been defined to obtain ranges of motion (R.O.M.) analogous to those of the physical prototype. To imitate the tendon which actuates a finger, a number of point forces have been defined. These point forces represent the reactive forces acting on the ...


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    Title :

    Modeling of Robotic Hand for Dynamic Simulation ; Modellering av robothand för dynamisk simulering


    Contributors:

    Publication date :

    2010-01-01


    Type of media :

    Theses


    Type of material :

    Electronic Resource


    Language :

    English



    Classification :

    DDC:    629