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Robotic haptics has been and continues to be an area of intense research, primarily in medical and exploration industries. This is due to an ability to provide high data throughput between human and machine. In medical applications, it is possible to detect and compensate errors such as a hand tremor in a surgeon. It is possible to apply scaling factors to assist in microsurgery situations, and can allow leading experts to perform procedures from anywhere on the globe. As part of a collaboration to develop a robotic method of femur fracture realignment between Auckland University, Auckland District Health Board, and Massey University, the project seeks to provide a haptic driven HMI for the realignment system. To reduce construction required, an existing manipulation arm (Mitsubishi RV-M1) is used as the hardware interface device. A new motor controller is designed to provide additional functionality as the standard controller provides no force control or real-time feedback of position. A software interface is developed (using version 3 of the C# programming language, developed by Microsoft, and version 3.5 of the Microsoft .NET Framework) with the ultimate specification of becoming being the primary interface platform for the realignment system. The interface has been implemented to the point of providing a simulated environment for the haptic device. It was found that the configuration of the RV-M1 provides a tight area of high dexterity as a haptic device, and as such, similar kinematic configurations are poor candidates for practical implementation. The implication of which, is that a new manipulator should be designed which grants a larger volume of high dexterity space.

Modern Rapid Prototyping (RP) technology has been available for more than a decade and has aided in shortening product development times and costs in the manufacturing sector. Stereolithography (SL), the most mature of RP technology, has primarily been used to build small to medium sized parts although there are largescale applications i.e. the automotive industry that uses “mammoth SLA”. Recent developments in SL have been aimed at increasing the speed of the additive process of most SL apparatus (SLA). Developments include the chemistry of photopolymer resins, integral-curing processes as opposed to vector-by-vector processes, and what is now called microstereolithography. Integral curing has been made possible by the advent of dynamic masking generators such as liquid crystal displays (LCDs) and digital micromirror devices (DMDs). Much of the theory for this new layering process has been applied to the micro-scale and awaits application for medium to large sized parts. The Limaye Model was applied to a microstereolithography apparatus (µSLA) and used as a process planning method for curing dimensionally accurate micro parts. Examination of the results of this mathematical model shows an irradiance map simulating the irradiances on the resin surface. The light is expected to attenuate from the central axis according to a measured irradiance curve. Improvements can be made to the Limaye Model to make it applicable for the process planning of medium to large parts. It is the aim of this research to present an improved mathematical model of the Limaye Model, so that a given irradiance map will produce an evenly distributed irradiance and account for errors in the optical imaging system. It is hoped that the field of exposure of 200mm x 270mm or larger will be achieved.

Robotics is an emerging field, and it is also affecting several other fields. Design of robotic platforms gains more importance since the focus and aim of the robotics research broadens widely and the variety of the users is significant. This work aims to present the design of a modular mobile robotic platform, which should be simple, easy to build and easy to use. The concept of modularity, usage of off-the shelf components and utilizing a PC platform, are addressed in this work. As a result of this work, a conceptual design is presented, and a prototype is built to highlight some important aspects of the conceptual design.

This thesis describes a system which is able to track and imitate human motion. The system is divided into two major parts: computer vision system and robot arm motion control system. Through the use of two real-time video cameras, computer vision system identifies the moving object depending on the colour features, as the object colour is matched within the colour range in the current image frame, a method that employs two vectors is used to calculate the coordinates of the object. After the object is detected and tracked coordinates are saved to a pre-establish database in the purpose of further data processing, a mathematical algorithm is performed to the data in order to give a better robotic motion control. Robot arm manipulator responds with a move within its workspace which corresponds to a consequential human-type motion. Experimental outcomes have shown that the system is reliable and can successfully imitate a human hand motion in most cases.

<div>Polymer nanocomposites (PNC) have an excellent potential for in-situ strain sensing applications in static and dynamic loading scenarios. These PNCs have a polymer matrix of polyvinylidene fluoride (PVDF) with a conductive filler of multi-walled carbon nanotubes (MWCNT) and have both piezoelectric and piezoresistive characteristics. Generally, this composite would accurately measure either low-frequency dynamic strain using piezoresistive characteristic or high-frequency dynamic strains using piezoelectric characteristics of the MWCNT/PVDF film sensor. Thus, the frequency bands of the strain sensor are limited to either piezoresistive or piezoelectric ranges. In this study, a novel weighted fusion technique, called Piezoresistive/Piezoelectric Fusion (PPF), is proposed to combine both piezoresistive and piezoelectric characteristics to capture the wide frequency bands of strain measurements in real-time. This fuzzy logic (FL)-based method combines the salient features (i.e., piezoresistive and piezoelectric) of the nanocomposite sensor via reasonably accurate models to extend the frequency range over a wider band. The FL determines the weight of each signal based on the error between the estimated measurements and the actual measurements. These weights indicate the contribution of each signal to the final fused measurement. The Fuzzy Inference System (FIS) was developed using both optimization and data clustering techniques. In addition, a type-2 FIS was utilized to overcome the model’s uncertainty limitations. The developed PPF methods were verified with experimental data at different dynamic frequencies that were obtained from existing literature. The fused measurements of the MWCNT/PVDF were found to correlate very well with the actual strain, and a high degree of accuracy was achieved by the subtractive clustering PPF’s FISs algorithm. <br></div><div><br></div><div>3D force sensors have proven their effectiveness and relevance for robotics applications. They have also been used in medical and physical therapy applications such as surgical robots and Instrument Assisted Soft Tissue Manipulation (IASTM). The 3D force sensors have been utilized in robot-assisted surgeries and modern physical therapy devices to monitor the 3D forces for improved performances. The 3D force sensor performance and specifications depend on different design parameters, such as the structural configuration, placement of the sensing elements, and load criterion. In this work, different bioinspired structure configurations have been investigated and analyzed to obtain the optimal 3D force sensor configuration in terms of structural integrity, compactness, the safety factor, and strain sensitivity. A Finite Element Analysis (FEA) simulation was used for the analysis to minimize the time of the development cycle.</div><div><br></div><div><br></div><div>A tree branch design was used as the 3D force sensor’s elastic structure. The structure was made of aluminum with a laser-cutting fabrication process. The PVDF/MWCNT films contained piezoresistive and piezoelectric characteristics that allowed for static/low strain measurements and dynamic strain measurements, respectively. Two compositions with 0.1 wt.% and 2 wt.% PVDF/MWCNT sensing elements were selected for piezoelectric and piezoresistive strain measurements, respectively. These characteristic measurements were investigated under different vibration rates in a supported beam experiment. The 3D force sensor was tested under dynamic excitation in the Z-direction and the X-direction. A Direct Piezoresistive/Piezoelectric Fusion (DPPF) method was developed by fusing the piezoresistive and piezoelectric measurements at a given frequency that overcomes the limited frequency ranges of each of the strain sensor characteristics. The DPPF method is based on a fuzzy inference system (FIS) which is constructed and tuned using the subtractive clustering technique. Different nonlinear Hammerstein-Wiener (nlhw) models were used to estimate the actual strain from piezoresistive and piezoelectric measurements at the 3D force sensor. The DPPF method was tested and validated for different strain signal types using presumed Triangle and Square signal waves data. The DPPF has proven its effectiveness in fusing piezoresistive and piezoelectric measurements with different types of signals. In addition, an Extended Direct Piezoresistive/Piezoelectric Fusion (EPPF) is introduced to enhance the DPPF method and perform the fusion in a range of frequencies instead of a particular one. The DPPF and EPPF methods were implemented on the 3D force sensor data, and the developed fusion algorithms were tested on the proposed 3D force sensor experimental data. The simulation results show that the proposed fusion methods have been effective in achieving lower Root Mean Square Error (RMSE) than those obtained from the tuned nlhw models at different operating frequencies.</div>