This thesis focuses on the detailed design, implementation, and testing of a unique high performance rotary actuator for use in a custom haptic force feedback device. This six degree of freedom (DoF) position input and three DoF force output haptic device is specifically designed to recreate force sensations with the goal of improving operator performance in remote or simulated environments. By upholding the strict design principles of an ideal force-source actuator, the developed actuator and consequently the haptic controller can successfully replicate forces accurately and realistically. In the comprehensive presentation of this design, numerous analytical tools are also developed and presented with the intention of them being resourceful in the design or improvement of other haptic actuators, specifically cable-driven force feedback designs. These tools which include a linear system model can be valuable not only in the development but in the control of cable-driven actuators. Due to the imposed design criteria, the developed 1.045 Nm (1.359 Nm peak) cable-driven sectorial rotary actuator exhibits numerous properties that are desired in an open-loop force controlled actuator. These properties include low inertia (6.53e-04 kgm^2), low perceived mass (0.102 kg), small torque resolution (3.84e-04 Nm), small position resolution (21.5 arcsec), and high bandwidth (300 Hz). Due to the efficient cable transmission the design is also backdrivable, isotropic, low friction, and zero backlash. As a result of these numerous intrinsic properties, a high fidelity force feedback haptic actuator was conceived and is presented in this thesis. / Master of Science

The importance of automating the garment manufacturing process has been understood since the early 1980s. However, in spite of millions of dollars spent on research, three decades later, the industry is still far from achieving a fully autonomous process. Previous work on fabric control in automated sewing focused on the control of only a single sheet of fabric using an industrial manipulator with an overhead vision system. These methods did not meet the accuracy and robustness requirements of the sewing process with respect to fabric position and fabric tension. To address these issues, a new method for fabric control in automated sewing is described. It uses the current feed mechanism on sewing machines, feed dogs, but modifies them to be servo-controlled. These servo controlled actuators, servo dogs, individually control two sheets of fabric before the fabric reaches the needle and during the sewing process. The servo dogs actuate the fabric 180o out of phase with the sewing needle, providing incremental control of the fabric when the needle is out of the fabric. To achieve this type of control successfully for automated sewing, the servo dogs have been designed for short displacement, high acceleration motions using a cable drive system powered by voice coil motors. Feedback of fabric position has been determined to be necessary and is to be provided by a thread-tracking vision system. This thesis outlines the general design of the system and discusses a prototype used to validate the design, and describes experiments performed to examine how the fabric will behave with the use of this type of actuation method.