Engineering activities by nature are collaborative endeavors. Single-user applications like CAD, CAE, and CAM force a strictly serial design process, which ultimately lengthens time to market. New multi-user applications such as NXConnect address the issue during the design stage of the product development process by enabling users to work in parallel. Multi-user collaborative tool path planning software addresses the same serial limitations in tool path planning, thereby decreasing cost and increasing the quality of manufacturing processes. As part complexity increases, lead times are magnified by serial workflows. Multi-user tool path planning can shorten the process planning time. But, to be effective, it must be possible to intelligently decompose the manufacturing sequence and distribute path planning assignments among several users. A new method of process decomposition is developed and described in this research. A multi-user CAM (MUCAM) prototype was developed to test the method. The decomposition process and MUCAM prototype together were used to manufacture a part to verify the method.

Additive manufacturing (AM) has received much attention from researchers over the past decades because of its diverse applications in various industries. AM is an advanced manufacturing process that facilitates the fabrication of complex geometries represented by computer-aided design (CAD) models. Traditionally, designed parts are fabricated by extruding material layer-by-layer using a tool path planning obtained from slicing programs by using CAD models as an input. Recently, there has been a growing interest in non-planar AM technologies, which offer the ability to fabricate multilayer constructs conforming to freeform surfaces. Non-planar AM processes have been utilized in various applications and involved objects of varying material properties and geometric characteristics. Although the current state of the art suggests AM can provide novel opportunities in conformal manufacturing, several challenges remain to be addressed. The identified challenges in non-planar AM fall into three categories: 1) conformal 3D printing on substrates with complex topography of which CAD model representation is not readily available, 2) understanding the relationship between the tool path planning and the quality of the 3D-printed construct, and 3) conformal 3D printing in the presence of mechanical disturbances. An open-loop non-planar tool path planning algorithm based on point cloud representations of object geometry and a closed-loop non-planar tool path planning algorithm based on position sensing were proposed to address these limitations and enable conformal 3D printing and spatiotemporal 3D sensing on objects of near-arbitrary organic shape. Three complementary studies have been completed towards the goal of improving the conformal tool path planning capabilities in various applications including fabrication of conformal electronics, in situ bioprinting, and spatiotemporal biosensing: i. A non-planar tool path planning algorithm for conformal microextrusion 3D printing based on point cloud data representations of object geometry was presented. Also, new insights into the origin of common conformal 3D printing defects, including tool-surface contact, were provided. The impact and utility of the proposed conformal microextrusion 3D printing process was demonstrated by the fabrication of 3D spiral and Hilbert-curve loop antennas on various non-planar substrates, including wrinkled and folded Kapton films and origami. ii. A new method for closed-loop controlled 3D printing on moving substrates, objects, and unconstrained human anatomy via real-time object position sensing was proposed. Monitoring of the tool position via real-time sensing of nozzle-surface offset using 1D laser displacement sensors enabled conformal 3D printing on moving substrates and objects. The proposed control strategy was demonstrated by microextrusion 3D printing on oscillating substrates and in situ bioprinting on an unconstrained human hand. iii. A reverse engineering-driven collision-free path planning program for automated inspection of macroscale biological specimens, such as tissue-based products and organs, was proposed. The path planning program for impedance-based spatiotemporal biosensing was demonstrated by the characterization of meat and fruit tissues using two impedimetric sensors: a cantilever sensor and a multifunctional fiber sensor. / Doctor of Philosophy / Additive Manufacturing (AM), commonly referred to as 3D printing, is a computer-aided manufacturing process that facilitates the fabrication of personalized and customized models, tissues, devices, and wearables. AM has several advantages over traditional manufacturing processes. For example, directing computer-driven robotics enables control over spatial structure and composition of parts. While 3D printing is typically performed using layer-by-layer planar tool paths generated by slicing programs, non-planar 3D printing is an emerging area that has recently been examined for various post-processing applications. Processes that enable material deposition conforming to complex geometric and freeform objects (e.g., anatomical structures), are central to various industries, including additive manufacturing, electronics manufacturing, and biomanufacturing. In this dissertation, tool path planning methods and real-time control strategies for non-planar 3D printing onto stationary and moving arbitrary surfaces, and various conformal electronics and in situ bioprinting applications will be presented. In addition to the tool path planning methods for 3D printing, a collision-free path planning program will be proposed for the inspection of large tissues and organs. The utility of the proposed method will be demonstrated through electrical impedance-based biosensing of meat and fruit to characterize their compositional and physiochemical properties which are used for quality assessment.

Over the past few years, manufacturing companies have had to deal with an increasing demand for feature-rich products at low costs. The pressures exerted on their existing manufacturing processes have lead manufacturers to investigate internet-based solutions, in order to cope with growing competition. Today, the availability of powerful and low cost 3D tools, along with web-based technologies, provides interesting opportunities to the manufacturing community, with solutions directly implementable at the core of their businesses and organizations. The wooden sign is custom i.e. each sign is completely different from each other. Mass Customization is a paradigm that produces custom products in masses. A wooden sign is custom in nature, and each sign must be completely different from another. Although process planning for mass customized products is same, the tool path required to CNC machine the custom feature varies from part to part. If the tool path is created manually the economics of mass production are challenged. The only viable option is to generate the tool path automatically; furthermore, any time savings in the tool path lead to better profit margins. This thesis presents the automatic web-based tool path planning method for machining sculptured wooden sign on 3 axis Computer Numerical Controlling (CNC) Machines using optimal and cost-effective milling cutters. The web-based tool path planning strategy is integrate with web-based CAD system to automatically generate tool paths for the CAD model using optimal cutter within desired tolerances. The tool path planning method is divided into two parts: foot print (path along which cutter moves) and cutter positioning. The tool path foot print is developed during design stage from the CAD model based on the type of surface to be machined. The foot print varies from part to part which facilitates the mass customization of wooden sign. After designing foot print, the foot print is discretized into points and the gouge-free cutter position at each of these points is found using "Dropping Method". The Dropping Method where cutter is dropped over the work piece surface, and the highest depth at which cutter can go without gouging the surface is calculated. This is repeated for all the position along the foot print. This tool path planning strategy is developed for ball nose, flat-end and radiused end milling cutter for machining wooden sign. The tool path generated using this method is optimized for machining time, tool path generation time and final surface finish. The bucketing technique is developed to optimize tool path generation time, by isolating the triangles which has possibility of intersection at particular position. The bucketing Technique reduced the tool path computation by 75 %, and made tool path generation faster. The optimal cutter selection algorithm is developed which selects best cutter for machining the surface based on the scallop height and volume removal results. The radiused end milling cutter results in highest volume removal which results in lower machining time compared to ball nose end milling cutters, but the scallop heights is higher. However, the scallop height in the radiused end milling cutter is higher only in few regions which reduces the final surface finish. For a sign, it was found around the boundary of logo, outline of lettering, interface of border and background. Thus, in order to achieve higher surface finish and lower machining time, a separate tool path is developed using "Pencil Milling Technique" which will remove the scallops from the regions that was inaccessible by radiused end mills. This tool path with the smaller cutter will move around the boundary of logo and lettering, and clean-up all the scallops left on the surface. The designed tool path for all the three cutters were tested on maple wood and verified against the actual Computer Aided Design model for scallop height and surface finish. The numerical testing of tool path was carried out on a Custom Simulator, ToolSim and was later confirmed by actually machining on a 3 axis CNC machine. The same sign was machined with variety of milling cutters and the best cutter was selected based on the minimum scallop and maximum volume removal. The results of the experimental verification show the method to be accurate for machining sculptured sign. The average scallop height in a machined using 1/8 th inch radiused end milling cuter and using Pencil tool path on the machined surface is found to be 0.03989 mm (1.5708 thou).

Over the past few years, manufacturing companies have had to deal with an increasing demand for feature-rich products at low costs. The pressures exerted on their existing manufacturing processes have lead manufacturers to investigate internet-based solutions, in order to cope with growing competition. Today, the availability of powerful and low cost 3D tools, along with web-based technologies, provides interesting opportunities to the manufacturing community, with solutions directly implementable at the core of their businesses and organizations. The wooden sign is custom i.e. each sign is completely different from each other. Mass Customization is a paradigm that produces custom products in masses. A wooden sign is custom in nature, and each sign must be completely different from another. Although process planning for mass customized products is same, the tool path required to CNC machine the custom feature varies from part to part. If the tool path is created manually the economics of mass production are challenged. The only viable option is to generate the tool path automatically; furthermore, any time savings in the tool path lead to better profit margins. This thesis presents the automatic web-based tool path planning method for machining sculptured wooden sign on 3 axis Computer Numerical Controlling (CNC) Machines using optimal and cost-effective milling cutters. The web-based tool path planning strategy is integrate with web-based CAD system to automatically generate tool paths for the CAD model using optimal cutter within desired tolerances. The tool path planning method is divided into two parts: foot print (path along which cutter moves) and cutter positioning. The tool path foot print is developed during design stage from the CAD model based on the type of surface to be machined. The foot print varies from part to part which facilitates the mass customization of wooden sign. After designing foot print, the foot print is discretized into points and the gouge-free cutter position at each of these points is found using "Dropping Method". The Dropping Method where cutter is dropped over the work piece surface, and the highest depth at which cutter can go without gouging the surface is calculated. This is repeated for all the position along the foot print. This tool path planning strategy is developed for ball nose, flat-end and radiused end milling cutter for machining wooden sign. The tool path generated using this method is optimized for machining time, tool path generation time and final surface finish. The bucketing technique is developed to optimize tool path generation time, by isolating the triangles which has possibility of intersection at particular position. The bucketing Technique reduced the tool path computation by 75 %, and made tool path generation faster. The optimal cutter selection algorithm is developed which selects best cutter for machining the surface based on the scallop height and volume removal results. The radiused end milling cutter results in highest volume removal which results in lower machining time compared to ball nose end milling cutters, but the scallop heights is higher. However, the scallop height in the radiused end milling cutter is higher only in few regions which reduces the final surface finish. For a sign, it was found around the boundary of logo, outline of lettering, interface of border and background. Thus, in order to achieve higher surface finish and lower machining time, a separate tool path is developed using "Pencil Milling Technique" which will remove the scallops from the regions that was inaccessible by radiused end mills. This tool path with the smaller cutter will move around the boundary of logo and lettering, and clean-up all the scallops left on the surface. The designed tool path for all the three cutters were tested on maple wood and verified against the actual Computer Aided Design model for scallop height and surface finish. The numerical testing of tool path was carried out on a Custom Simulator, ToolSim and was later confirmed by actually machining on a 3 axis CNC machine. The same sign was machined with variety of milling cutters and the best cutter was selected based on the minimum scallop and maximum volume removal. The results of the experimental verification show the method to be accurate for machining sculptured sign. The average scallop height in a machined using 1/8 th inch radiused end milling cuter and using Pencil tool path on the machined surface is found to be 0.03989 mm (1.5708 thou).