A. James Clark School of Engineering
Permanent URI for this communityhttp://hdl.handle.net/1903/1654
The collections in this community comprise faculty research works, as well as graduate theses and dissertations.
Browse
2 results
Search Results
Item Demonstrating Cognition by Task Execution and Motion Planning with different algorithms for Manipulation(2018) DIMITRIADIS, DIMITRIOS; Baras, John S.; Electrical Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)In this Thesis we demonstrate the whole path until the manipulation and the planning of the Baxter Robot. We start by analyzing the kinematic analysis of a six degrees of freedom robot. We build our analysis starting from the Denavit-Hartenberg method. We proceed with the kinematic equations of the robot and with the inverse kinematics as well as with a kinematic simulation of its movement with matlab. In order to reach our final goal we continue with the kinematic and dynamic analysis of the Baxter robot. We again state the Denavit-Hartenberg matrix, but this time we continue by building the dynamic model of the Baxter robot through the Euler-Lagrange equations. Moving on, we explore planning algorithms. The knowledge of which will help us in order to finally be able to formulate our path planner for the Baxter robot. We experiment ourselves by implementing four planning algorithms in different path planning problems. We construct the RRT and the RRT* algorithms in Python and we process them in different planning problems. Moving on, we also implement a planning problem in which Q-Learning and Sarsa algorithms are being used. We demonstrate how those two planning and learning algorithms work in our specified problem and we compare our results. Having knowledge on dynamic and kinematic robotic analysis and planning and motion planning algorithms we then experiment ourselves with the Baxter simulator on Gazebo. Also we plan the Baxter robot with Moveit!, getting familiar with the use of ROS as well as with the software. We add obstacles in our world and we plan our Baxter robot measuring its speed. We finally build a different plan algorithm RRT+ by focusing on searching for a secure and realizable path plan starting from the lower dimension space and then adding degrees of freedom to our Baxter robot. Concluding, we have built the desired steps for someone in order to build up the required knowledge to deal with robots and artificial intelligence planning.Item Motion of elastic capsules in microfluidic channels(2010) Kuriakose, Shugi; Dimitrakopoulos, Panagiotis; Chemical Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Capsule flow dynamics in microchannels plays a significant role in complex biological phenomena, such as the microcirculation, and in engineering applications, such as in microfluidic devices for drug delivery and cell sorting. In this thesis, we investigate the motion of elastic capsules in wall-bounded flows by extending the Membrane Spectral Boundary Element method developed by Dodson and Dimitrakopoulos for free-suspended flows. First, a validation study of the method is performed for the axisymmetric capsule motion in a cylindrical channel. For a capsule moving along the centerline of a cylindrical channel, our computational model successfully reproduced the parachute shape observed in earlier experimental and computational studies. Next, we investigate the flow dynamics of a strain-hardening Skalak capsule moving along the centerline in a square and a rectangular channel. We examine how the capillary number and capsule size influence the deformation and physical properties of the capsule. For large capsules in a square channel, our investigation reveals that the steady-state capsule shape is non-axisymmetric. The capsule assumes a shape similar to the channel's cross-section i.e. a square shape with rounded edges. Buckling of the capsule's upstream end resulting in a negative edge curvature is observed at higher capillary numbers and for large capsule sizes. For the largest capsules studied, we also observe the development of dimples at the capsule's lateral surface. A comparative study of capsule motion and deformation in cylindrical and square channels shows that the capsule deformation in a cylindrical channel is similar to that in a square channel at a larger capillary number. In a rectangular channel, we observe a three-dimensional (i.e. non-axisymmetric) deformation of the capsule at high capillary numbers resulting in dimpling of the capsule's upstream end at steady state. We also consider the transient motion of a capsule in a converging square microchannel and investigate the influence of viscosity ratio, capillary number and capsule size on the evolution of capsule properties. As the capsule moves through the converging region a fluctuation in the geometric and physical properties of the capsule is observed.