Efficiency of a gyroscopic device for conversion of mechanical wave energy to electrical energy:Technical report from ESGI-83 workshop in industrial mathematics 2011

We consider a recently proposed gyroscopic device for conversion of mechanical ocean wave energy to electrical energy. Two models of the device derived from standard engineering mechanics from the literature are analysed, and a model is derived from analytical mechanics considerations. From these models, estimates of the power production, efficiency, forces and moments are made. We find that it is possible to extract a significant amount of energy from an ocean wave using the described device. Further studies are required for a full treatment of the device.Resulting from the interaction with Joltech A/S at ESGI-83 (European Study Group with Industry) workshop on industrial mathematics, Sønderborg Denmark, 2011.</p

Development of an integrated robotic polishing system

This thesis presents research carried out as part of a project undertaken in fulfilment of the requirements of Loughborough University for the award of Philosophical Doctorate. The main focus of this research is to investigate and develop an appropriate level of automation to the existing manual finishing operations of small metallic components to achieve required surface quality and to remove superficial defects. In the manufacturing industries, polishing processes play a vital role in the development of high precision products, to give a desired surface finish, remove defects, break sharp edges, extend the working life cycle, and meet mechanical specification. The polishing operation is generally done at the final stage of the manufacturing process and can represent up to a third of the production time. Despite the growth automated technology in industry, polishing processes are still mainly carried out manually, due to the complexity and constraints of the process. Manual polishing involves a highly qualified worker polishing the workpiece by hand. These processes are very labour intensive, highly skill dependent, costly, error-prone, environmentally hazardous due to abrasive dust, and - in some cases - inefficient with long process times. In addition, the quality of the finishing is dependent on the training, experience, fatigue, physical ability, and expertise of the operator. Therefore, industries are seeking alternative solutions to be implemented within their current processes. These solutions are mainly aimed at replacing the human operator to improve the health and safety of their workforce and improve their competitiveness. Some automated solutions have already been proposed to assist or replace manual polishing processes. These solutions provide limited capabilities for specific processes or components, and a lack of flexibility and dexterity. One of the reasons for their lack of success is identified as neglecting the study and implementing the manual operations. This research initially hypothesised that for an effective development, an automated polishing system should be designed based on the manual polishing operations. Therefore, a successful implementation of an automated polishing system requires a thorough understanding of the polishing process and their operational parameters. This study began by collaborating with an industrial polishing company. The research was focused on polishing complex small components, similar to the parts typically used in the aerospace industry. The high level business processes of the polishing company were capture through several visits to the site. The low level operational parameters and the understanding of the manual operations were also captured through development of a devices that was used by the expert operators. A number of sensors were embedded to the device to facilitate recording the manual operations. For instance, the device captured the force applied by the operator (avg. 10 N) and the cycle time (e.g. 1 pass every 5 sec.). The capture data was then interpreted to manual techniques and polishing approaches that were used in developing a proof-of-concept Integrated Robotic Polishing System (IRPS). The IRPS was tested successfully through several laboratory based experiments by expert operators. The experiment results proved the capability of the proposed system in polishing a variety of part profiles, without pre-existing geometrical information about the parts. One of the main contributions made by this research is to propose a novel approach for automated polishing operations. The development of an integrated robotic polishing system, based on the research findings, uses a set of smart sensors and a force-position-by-increment control algorithm, and transpose the way that skilled workers carry out polishing processes

Dynamical system for learning the waveform and frequency of periodic signals - application to drumming

The paper presents a two-layered system for learning and encoding a periodic signal and its application to a drumming task. The two layers are the dynamical system responsible for extracting the main frequency of the input signal, based on adaptive frequency oscillators, and the dynamical system responsible for learning of the waveform with a built in learning algorithm. By combining the two dynamical systems we can rapidly teach new trajectories to robots. The systems works online for any periodic signal, requires no signal processing and can be applied in parallel to multiple dimensions. Furthermore, it can adapt to changes in frequency and shape, e.g. to non-stationary signals, and is computationally inexpensive. The algorithm is demonstrated in a drumming task using the HOAP-2 humanoid robot

Validation of a Device to Accurately Monitor Knee Kinematics during Dynamic Movements

The incidence of anterior cruciate ligament (ACL) injury in athletes who play multidirectional sports has increased over recent times. Female athletes are at a higher risk of sustaining the ACL injury when compared to their male counterparts involved in the same sport. Various intrinsic (anatomical and hormonal) and extrinsic (biomechanical) factors have been identified that contribute to the increased risk of injury. Sex differences in the kinematics and kinetics of the lower extremity between males and females have been identified while performing various physical tasks has been a topic of discussion since a long time. While it’s difficult to control the anatomical and hormonal factors, identifying and modifying the biomechanical factors that contribute to the ACL injury is possible. Wearable sensors involving inertial measurement units (IMUs) have been developed to monitor lower extremity motion and help in assistance with rehabilitation. The purpose of this study was to validate a set of wearable IMUs against a 3D motion analysis system to monitor the lower extremity motion during jumps and runs in a laboratory and to determine whether IMUs could be used to estimate ground reaction force at landing. An average difference of 5°-10° for flexion, 4°-6° abduction and internal rotation was reported during jump and run. The results of this study showed that correlation between ground reaction force and tibial acceleration is poor when data from all the subjects were included together. However, the correlation was improved when subjects were examined individually. A strong correlation was observed between the resultant ground reaction force and the resultant tibial acceleration during jumping and running between both the legs for the eight subjects when examined individually.Master of Science in EngineeringMechanical Engineering, College of Engineering & Computer ScienceUniversity of Michigan-Dearbornhttps://deepblue.lib.umich.edu/bitstream/2027.42/146786/1/49698122_Thesis report_Ruchika Tadakala_36771515 edited (2).pdfDescription of 49698122_Thesis report_Ruchika Tadakala_36771515 edited (2).pdf : Thesi