Remixing physical objects through tangible tools

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2011.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student submitted PDF version of thesis.Includes bibliographical references (p. 147-164).In this document we present new tools for remixing physical objects. These tools allow users to copy, edit and manipulate the properties of one or more objects to create a new physical object. We already have these capabilities using digital media: we can easily mash up videos, music and text. However, it remains difficult to remix physical objects and we cannot access the advantages of digital media, which are nondestructive, scalable and scriptable. We can bridge this gap by both integrating 2D and 3D scanning technology into design tools and employing aordable rapid prototyping technology to materialize these remixed objects. In so doing, we hope to promote copying as a tool for creation. This document presents two tools, CopyCAD and KidCAD, the first designed for makers and crafters, the second for children. CopyCAD is an augmented Computer Numerically Controlled (CNC) milling machine which allows users to copy arbitrary real world object geometry into 2D CAD designs at scale through the use of a camera-projector system. CopyCAD gathers properties from physical objects, sketches and touch interactions directly on a milling machine, allowing novice users to copy parts of real world objects, modify them and create a new physical part. KidCAD is a sculpting interface built on top of a gel-based realtime 2.5D scanner. It allows children to stamp objects into the block of gel, which are scanned in realtime, as if they were stamped into clay. Children can use everyday objects, their hands and tangible tools to design new toys or objects that will be 3D printed. This work enables novice users to easily approach designing physical objects by copying from other objects and sketching new designs. With increased access to such tools we hope that a wide range of people will be empowered to create their own objects, toys, tools and parts.by Sean Follmer.S.M

Automated CNC Tool Path Planning and Machining Simulation on Highly Parallel Computing Architectures

This work has created a completely new geometry representation for the CAD/CAM area that was initially designed for highly parallel scalable environment. A methodology was also created for designing highly parallel and scalable algorithms that can use the developed geometry representation. The approach used in this work is to move parallel algorithm design complexity from an algorithm level to a data representation level. As a result the developed methodology allows an easy algorithm design without worrying too much about the underlying hardware. However, the developed algorithms are still highly parallel because the underlying geometry model is highly parallel. For validation purposes, the developed methodology and geometry representation were used for designing CNC machine simulation and tool path planning algorithms. Then these algorithms were implemented and tested on a multi-GPU system. Performance evaluation of developed algorithms has shown great parallelizability and scalability; and that main algorithm properties are required for modern highly parallel environment. It was also proved that GPUs are capable of performing work an order of magnitude faster than traditional central processors. The last part of the work demonstrates how high performance that comes with highly parallel hardware can be used for development of a next level of automated CNC tool path planning systems. As a proof of concept, a fully automated tool path planning system capable of generating valid G-code programs for 5-axis CNC milling machines was developed. For validation purposes, the developed system was used for generating tool paths for some parts and results were used for machining simulation and experimental machining. Experimental results have proved from one side that the developed system works. And from another side, that highly parallel hardware brings computational resources for algorithms that were not even considered before due to computational requirements, but can provide the next level of automation for modern manufacturing systems

Virtual reality based creation of concept model designs for CAD systems

This work introduces a novel method to overcome most of the drawbacks in traditional methods for creating design models. The main innovation is the use of virtual tools to simulate the natural physical environment in which freeform. Design models are created by experienced designers. Namely, the model is created in a virtual environment by carving a work piece with tools that simulate NC milling cutters. Algorithms have been developed to support the approach, in which the design model is created in a Virtual Reality (VR) environment and selection and manipulation of tools can be performed in the virtual space. The desianer\u27s hand movements generate the tool trajectories and they are obtained by recording the position and orientation of a hand mounted motion tracker. Swept volumes of virtual tools are generated from the geometry of the tool and its trajectories. Then Boolean operations are performed on the swept volumes and the initial virtual stock (work piece) to create the design model. Algorithms have been developed as a part of this work to integrate the VR environment with a commercial CAD/CAM system in order to demonstrate the practical applications of the research results. The integrated system provides a much more efficient and easy-to-implement process of freeform model creation than employed in current CAD/CAM software. It could prove to be the prototype for the next-generation CAD/CAM system

A STUDY OF THE APPLICATION OF AUGMENTED REALITY TECHNOLOGY ON 3-AXIS CNC IN SITU MACHINING SIMULATION

Ph.DDOCTOR OF PHILOSOPH

Robotic Implant Modification for Neuroplastic Surgery

Neuroplastic surgery, which combines neurosurgery with plastic surgery, is a novel field that has not been rigorously studied. It has crucial clinical potentials in implanting instrumented devices for brain imaging, targeted drug delivery, deep brain stimulation, shunt placement, and so on. A specific application of neuroplastic surgery is single-stage cranioplasty. Current practice involves resizing a prefabricated oversized customized cranial implant (CCI). This method provides intraoperative flexibility for skull resection. However, surgeons need to manually resize the CCI to fit the craniofacial bone defect based on their judgment and estimation. This manual modification can be time-consuming and imprecise, resulting in large bone gaps between the skull and the resized implant. This work investigates the possibility of applying robotic and computer-integrated techniques to improve the procedure. This dissertation describes the development and examination of several systems to address the challenges that emerged from the CCI resizing process: (i) To assist the manual modification, a portable projection mapping device (PPMD) provides precise real-time visual guidance for surgeons to outline the defect boundary on the oversized CCI. (ii) Even with the assistance of a projection system, the subsequent manual resizing may still be imprecise and prone to failure. This work introduces an automated workflow for intraoperative CCI modification using a robotic system. (iii) A 2-scan method accomplishes the patient-to-CT registration using a handheld 3D scanner and addresses the challenges posed by the soft tissues and the surgical draping requirement using reattachable fiducial markers. (iv) A toolpath algorithm generates a cutting toolpath for the robot to resize the implant based on the defect geometry. (v) Due to certain limitations associated with mechanical cutting, this work presents a 5-axis CO\textsubscript{2} laser cutting system that achieves fast and precise implant modification, ideal for fabricating instrumented implants. The evaluation of the automated workflow shows a significant improvement in CCI resizing accuracy. This indicates lower risk of implant failure causing post-surgical complications. Furthermore, the functions provided by these systems can be expanded to other neuroplastic applications

Bipedal humanoid robot control by fuzzy adjustment of the reference walking plane

The two-legged humanoid structure has advantages for an assistive robot in the human living and working environment. A bipedal humanoid robot can avoid typical obstacles at homes and offices, reach consoles and appliances designed for human use and can be carried in human transport vehicles. Also, it is speculated that the absorption of robots in the human shape into the human society can be easier than that of other artificial forms. However, the control of bipedal walk is a challenge. Walking performance on solely even floor is not satisfactory. The complications of obtaining a balanced walk are dramatically more pronounced on uneven surfaces like inclined planes, which are quite commonly encountered in human surroundings. The difficulties lie in a variety of tasks ranging from sensor and data fusion to the design of adaptation systems which respond to changing surface conditions. This thesis presents a study on bipedal walk on inclined planes with changing slopes. A Zero Moment Point (ZMP) based gait synthesis technique is employed. The pitch angle reference for the foot sole plane −as expressed in a coordinate frame attached at the robot body − is adjusted online by a fuzzy logic system to adapt to different walking surface slopes. Average ankle pitch torques and the average value of the body pitch angle, computed over a history of a predetermined number of sampling instants, are used as the inputs to this system. The proposed control method is tested via walking experiments with the 29 degreesof- freedom (DOF) human-sized full-body humanoid robot SURALP (Sabanci University Robotics Research Laboratory Platform). Experiments are performed on even floor and inclined planes with different slopes. The results indicate that the approach presented is successful in enabling the robot to stably enter, ascend and leave inclined planes with 15 percent (8.5 degrees) grade. The thesis starts with a terminology section on bipedal walking and introduces a number of successful humanoid robot projects. A survey of control techniques for the walk on uneven surfaces is presented. The design and construction of the experimental robotic platform SURALP is discussed with the mechanical, electronic, walking reference generation and control aspects. The fuzzy reference adjustment system proposed for the walk on inclined planes is detailed and experimental results are presented

Development of an in-vitro passive and active motion Simulator for the investigation of wrist function and Kinematics

This thesis outlines the design and development of an active motion simulator for the investigation of wrist kinematics in multiple gravity loaded positions. Using optical trackers on the third metacarpal, radius, and ulna, the position of the wrist was monitored in real time without introducing material incompatibilities as present for electromagnetic tracking systems. Performance of the system was performed using a series of five cadaver upper limbs that compared the ability to produce repeatable trials using unrestrained active motion techniques over passive manipulation methods. Comparisons to achieve static positions as well as motion trials in flexion-extension and radial-ulnar deviation planes proved the superior performance of computer controlled motion over that of passive manipulation. Investigation into the application of tendon portioning to model in-vivo conditions more accurately suggest that they may improve overall quality of motion

Beitrag zur voxelbasierten Simulation des fünfachsigen NC-Fräsens

Die Simulationstechnik wird als Hilfsmittel zur Beherrschung der drei- und fünfachsigen NC-Fräsbearbeitung eingesetzt. Gewöhnlich wird die Aktualisierung des simulierten Werkstücks entweder im Bildraum des Werkstücks oder geometrisch im Objektraum durchgeführt. Die vollständige Aktualisierung des simulierten Werkstücks fordert jedoch nur eine geometrische Lösung. Im vorliegenden Forschungsbericht wird der Ansatz der voxelbasierten fünfachsigen NC-Simulation entwickelt. Die Grundlage für den Aufbau des Simulationssystems ist der am IPK Berlin entwickelte 3D-Kernmodellierer des Virtual Clay Modelling Systems. Dieser ermöglicht die Modellierung und die Aktualisierung von komplizierten Werkstücken und Zerspanungsvolumen in der drei- und fünfachsigen NC-Simulation auf Rechenanlagen. Das simulierte Werkstück wird rechnerintern diskret mit einem Voxelmodell dargestellt. Die dadurch eingeführten NC-Simulationsfehler werden unter Berücksichtigung des eingesetzten Fräsers kontrolliert. Eine voxelbasierte Methode zur Gestaltung von Zerspanungsvolumen der diversen Werkzeuge wie zylindrische Fräser, Torus-, zylindrische Gesenk-, Kugelkopf-, Fass-, Kegel- und kegelige Gesenkfräser wurde entwickelt. Der Vorteil dieser Methode liegt darin, dass aufgrund der diskreten Datenstruktur des Voxelmodells und der damit ermöglichten Abbildung von beliebigen Formen keinerlei Einschränkungen zur Modellierung der Zerspanungsvolumen der diversen Fräsertypen gegeben sind. Die Materialverletzungen und verbliebenen Restmaterialien auf dem simulierten Werkstück können im 3D-Raum zur Bewertung der Qualität der NC-Programme ermittelt werden. Eine effektive Optimierung der NC-Programme in der Fertigungsvorbereitung kann durchgeführt werden. Zur Beschleunigung der Werkstückaktualisierung wurden ausgehend von den Eigenschaften des Voxelmodells die entsprechenden Maßnahmen getroffen. Mit der vorgestellten Methode wird ein wichtiger Beitrag zur drei- und fünfachsigen Simulation des NC-Fräsens geleistet. Damit können die NC-Programme für die drei- und fünfachsige NC-Fräsbearbeitung verifiziert, optimiert und die Prozessqualität vorab sichergestellt werden