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Full-Text Articles in Engineering

Stiffness Characterisation Of Microcantilevers Based On Conducting Polymers, Gursel Alici, Michael J. Higgins Feb 2013

Stiffness Characterisation Of Microcantilevers Based On Conducting Polymers, Gursel Alici, Michael J. Higgins

Gursel Alici

The object of this paper is to characterise the stiffness of microfabricated cantilevers consisting of two electroactive polymer (polypyrrole (PPy)) layers, and two gold layers with a negligible thickness and a layer of porous polyvinylidene fluoride (PVDF), which serves as a backing layer and electrolyte storage tank. This composite cantilever structure is used as polymer actuators or famously known as artificial muscles when tailored appropriately. The polymer microactuators considered in this study, which were fabricated using a laser ablation technique, could operate both in aqueous and non-aqueous media. The stiffness characterization of the microactuators is critical to assess their suitability …


Wireless Aquatic Navigator For Detection And Analysis (Wanda), Cormac Fay, King-Tong Lau, Stephen T. Beirne, Ciaran O'Conaire, Kevin Mcguinness, Brian Corcoran, Noel O'Connor, Dermot Diamond, Scott T. Mcgovern, Greg Coleman, Roderick L. Shepherd, Gursel Alici, Geoffrey M. Spinks, Gordon G. Wallace Feb 2013

Wireless Aquatic Navigator For Detection And Analysis (Wanda), Cormac Fay, King-Tong Lau, Stephen T. Beirne, Ciaran O'Conaire, Kevin Mcguinness, Brian Corcoran, Noel O'Connor, Dermot Diamond, Scott T. Mcgovern, Greg Coleman, Roderick L. Shepherd, Gursel Alici, Geoffrey M. Spinks, Gordon G. Wallace

Gursel Alici

The cost of monitoring and detecting pollutants in natural waters is of major concern. Current and forthcoming bodies of legislation will continue to drive demand for spatial and selective monitoring of our environment, as the focus increasingly moves towards effective enforcement of legislation through detection of harmful events, and unambiguous identification of perpetrators. However, these monitoring demands are not being met due to the infrastructure and maintenance costs of conventional sensing models. Advanced autonomous platforms capable of performing complex analytical measurements at remote locations still require individual power, wireless communication, processor and electronic transducer units, along with regular maintenance visits. …


A New Adaptive Fuzzy-Hybrid Control Strategy Of Semi-Active Suspension With Magneto-Rheological Damper, Pipit Wahyu Nugroho, H Du, W H. Li, G Alici Feb 2013

A New Adaptive Fuzzy-Hybrid Control Strategy Of Semi-Active Suspension With Magneto-Rheological Damper, Pipit Wahyu Nugroho, H Du, W H. Li, G Alici

Gursel Alici

This paper presents the design and analysis of a new adaptive fuzzy (AF) logic and hybrid (skyhook plus groundhook) control technique applied to a semi-active suspension system of a quarter car mode. The hybrid control is applied because of its very good performance in ride comfort and road handling. Meanwhile, Fuzzy adaptive system is suitable for analysis of stability with non-linear performances. The adaptive fuzzy algorithm is used to approximate the estimated mass of the variable damping in the Hybrid loop. This model is adopting a Takagi-Sugeno configuration with a back propagation learning method typically used in a neural network …


Magnetic Propulsion Of A Spiral-Type Endoscopic Microrobot In A Real Small Intestine, Hao Zhou, Gursel Alici, Trung Duc Than, Weihua Li, Sylvain Martel Feb 2013

Magnetic Propulsion Of A Spiral-Type Endoscopic Microrobot In A Real Small Intestine, Hao Zhou, Gursel Alici, Trung Duc Than, Weihua Li, Sylvain Martel

Gursel Alici

This paper reports on the magnetic propulsion of a spiral-type endoscopic mircorobot in a real small intestine. Magnetic modeling was carried out to design and commission an external electromagnetic system, which wirelessly provides power to the robotic agent. The capsules with different spiral structures were magnetically propelled inside a segment of porcine small intestine. From the results, it is shown that the propulsive velocities of the tested capsules are in the range of 2.5 ~ 35 mm/s when rotating frequencies varying between 1 ~ 5 Hz are applied. Among all the capsules prepared for this study, the capsule No. 5, …


Polypyrrole Stretchable Actuators, Wen Zheng, Gursel Alici, Phillip R. Clingan, Bridget Munro, Geoffrey M. Spinks, Julie R. Steele, Gordon G. Wallace Feb 2013

Polypyrrole Stretchable Actuators, Wen Zheng, Gursel Alici, Phillip R. Clingan, Bridget Munro, Geoffrey M. Spinks, Julie R. Steele, Gordon G. Wallace

Gursel Alici

Here, we report a simple way to prepare stretchable polypyrrole (PPy)-based actuator materials that can be operated over a wide dynamic strain range and generate useable actuation displacements and pressures. The stretchable actuators were prepared as a laminated composite of PPy and a gold-coated roughened rubber sheet. By manipulating the corrugated surface of the rubber substrate, the stretchability of PPy was greatly improved. Gold-coated rubbers could be stretched to 30 percent without significant change in electrical resistance. The corrugated PPy/gold/rubber laminates successfully showed - 1 percents of actuation strain even when prestretched to 24 percent. The actuation strains were smaller …


Kinematic Analysis Of Electroactive Polymer Actuators As Soft And Smart Structures With More Dof Than Inputs, Rahim Mutlu, Gursel Alici, Weihua Li Feb 2013

Kinematic Analysis Of Electroactive Polymer Actuators As Soft And Smart Structures With More Dof Than Inputs, Rahim Mutlu, Gursel Alici, Weihua Li

Gursel Alici

Electroactive polymer (EAP) actuators have been attracting the attention of researchers due to their muscle-like behaviour and unusual properties. Several modelling methods have been proposed to understand their mechanical, chemical, electrical behaviours or ‘electro-chemo-mechanical’ behaviour. However, estimating the whole shape or configuration of the EAP actuators has always been challenging due to their highly non-linear bending behaviour. This paper reports on an effective method to estimate the whole shape deflection of the EAP actuators by employing a so-called backbone approach. Tri-layer configured polypyrrole (PPy) based EAP actuators were used as a soft and smart structure with more degrees of freedom …


Characterization And Modeling Of Conjugated Polymer Sensors, Yang Fang, Xiaobo Tan, Andrew Temme, Gursel Alici Oct 2012

Characterization And Modeling Of Conjugated Polymer Sensors, Yang Fang, Xiaobo Tan, Andrew Temme, Gursel Alici

Gursel Alici

In this paper the behavior of conjugated polymers as mechanical sensors is experimentally characterized and modeled. A trilayer conjugated polymer sensor is considered, where two polypyrrole (PPy) layers sandwich an amorphous polyvinylidene fluoride (PVDF) layer, with the latter serving as an electrolyte tank. A theory for the sensing mechanism is proposed by postulating that, through its influence on the pore structure, mechanical deformation correlates directly to the concentration of ions at the PPy/PVDF interface. This provides a key boundary condition for the partial differential equation (PDE) governing the ion diffusion and migration dynamics. By ignoring the migration term in the …


Enhancement Of Actuation Ability Of Ionic-Type Conducting Polymer Actuators Using Metal Ion Implantation, G Alici, Andres Punning, Herbert R. Shea Oct 2012

Enhancement Of Actuation Ability Of Ionic-Type Conducting Polymer Actuators Using Metal Ion Implantation, G Alici, Andres Punning, Herbert R. Shea

Gursel Alici

In this study, we present the results and implications of an experimental study into the effect of gold-ion implantation on the actuation performance of ionic-type conducting polymer actuators, represented here by cantilevered tri-layer polypyrrole (PPy) actuators. We implant gold ions beneath the outer surfaces of PPy-based conducting polymer layers of the actuators in order to increase the conductivity of these layers, and therefore improve the overall conductivity of the actuators. A Filtered Vacuum Cathode Arc (FVCA) ion source was used to implant gold particles into the conducting polymer layers. Electrode resistance and capacitance, surface resistance, current response, mechanical work output …


Deformable Object Modelling Through Cellular Neural Network, Yongmin Zhong, Bijan Shirinzadeh, Gursel Alici, Julian Smith, Denny Oetomo Oct 2012

Deformable Object Modelling Through Cellular Neural Network, Yongmin Zhong, Bijan Shirinzadeh, Gursel Alici, Julian Smith, Denny Oetomo

Gursel Alici

This paper presents a new methodology for the deformable object modelling by drawing an analogy between cellular neural network (CNN) and elastic deformation. The potential energy stored in an elastic body as a result of a deformation caused by an external force is propagated among mass points by the non-linear CNN activity. An improved autonomous CNN model is developed for propagating the energy generated by the external force on the object surface in the natural manner of heat conduction. A heat flux based method is presented to derive the internal forces from the potential energy distribution established by the CNN. …


Frequency Response Of Polypyrrole Trilayer Actuator Displacement, Stephen John, Gursel Alici, Christopher David Cook Oct 2012

Frequency Response Of Polypyrrole Trilayer Actuator Displacement, Stephen John, Gursel Alici, Christopher David Cook

Gursel Alici

Conducting polymer trilayers are attractive for use in functional devices, given low actuation voltages, operation in air and potentially useful stresses and strains; however, their dynamic behavior must be understood from an engineering perspective before they can be effectively incorporated into a design. As a step towards the identification of the actuator dynamics, frequency response analysis has been performed to identify the magnitude and phase shift of displacement in response to a sinusoidal voltage input. The low damping of the trilayer operating in air and the use of a laser displacement sensor has allowed the frequency response to be continuously …


Experimental Evaluation Of Adaptive And Variable Structure Control Of Piezoelectric Actuation Systems For Micro/Nano Manipulation, Hwee Choo Liaw, Bijan Shirinzadeh, Denny Oetomo, Gursel Alici Oct 2012

Experimental Evaluation Of Adaptive And Variable Structure Control Of Piezoelectric Actuation Systems For Micro/Nano Manipulation, Hwee Choo Liaw, Bijan Shirinzadeh, Denny Oetomo, Gursel Alici

Gursel Alici

This paper proposes and evaluates an adaptive technique and a variable structure control approach for piezoelectric actuation systems to track specified motion trajectories. The proposed control methodologies are formulated to accommodate unknown or uncertain system parameters, nonlinearities including the hysteresis effect, and external disturbances in the piezoelectric actuation systems without any form of feed-forward compensation. In this study, both control methodologies are demonstrated to possess a promising motion tracking ability experimentally. In comparison, the variable structure control approach is evaluated to be superior to the adaptive technique in the motion tracking control. With the ability to track motion trajectories under …


Towards The Position Control Of Conducting Polymer Trilayer Bending Actuators With Integrated Feedback Sensor, Stephen John, Gursel Alici, Christopher D. Cook Oct 2012

Towards The Position Control Of Conducting Polymer Trilayer Bending Actuators With Integrated Feedback Sensor, Stephen John, Gursel Alici, Christopher D. Cook

Gursel Alici

Conducting polymers have a wide range of reversibly controllable properties, leading to a number of potentially useful devices for robotic applications, including actuators, sensors and batteries. Conducting polymers have the advantages of low weight, low cost, flexibility, small activation potentials (


Cellular Neural Network Based Deformation Simulation With Haptic Force Feedback, Yongmin Zhong, Bijan Shirinzadeh, Gursel Alici, Julian Smith Oct 2012

Cellular Neural Network Based Deformation Simulation With Haptic Force Feedback, Yongmin Zhong, Bijan Shirinzadeh, Gursel Alici, Julian Smith

Gursel Alici

This paper presents a new methodology for deformable object modelling by drawing an analogy between cellular neural network (CNN) and elastic deformation. The potential energy stored in an elastic body as a result of a deformation caused by an external force is propagated among mass points by the non-linear CNN activity. An improved CNN model is developed for propagating the energy generated by the external force on the object surface in the natural manner of Poisson equation. The proposed methodology models non-linear materials with nonlinear CNN rather than geometric non-linearity in the most existing deformation methods. It can not only …


Robust Adaptive Control Of Conjugated Polymer Actuators, Yang Fang, Xiaobo Tan, Gursel Alici Oct 2012

Robust Adaptive Control Of Conjugated Polymer Actuators, Yang Fang, Xiaobo Tan, Gursel Alici

Gursel Alici

Conjugated polymers are promising actuation materials for bio- and micromanipulation systems, biomimetic robots, and biomedical devices. Sophisticated electrochemomechanical dynamics in these materials, however, poses significant challenges in ensuring their consistent, robust performance in applications. In this paper, an effective adaptive control strategy is proposed for conjugated polymer actuators. A self-tuning regulator is designed based on a simple actuator model, which is obtained through reduction of an infinite-dimensional physical model and captures the essential actuation dynamics. The control scheme is made robust against unmodeled dynamics and measurement noises with parameter projection, which forces the parameter estimates to stay within physically meaningful …


A Deformable Model With Cellular Neural Network, Yongmin Zhong, Bijan Shirinzadeh, Gursel Alici, Julian Smith Oct 2012

A Deformable Model With Cellular Neural Network, Yongmin Zhong, Bijan Shirinzadeh, Gursel Alici, Julian Smith

Gursel Alici

This paper presents a new methodology for deformable models by drawing an analogy between cellular neural network (CNN) and elastic deformation. The potential energy stored in an elastic body as a result of a deformation caused by an external force is propagated among mass points by the local connectivity of cells and the CNN dynamics. An improved CNN model is developed for propagating the energy generated by the external force on the object surface. A method is presented to derive the internal forces from the potential energy distribution established by the CNN. The methodology proposed in this paper can not …


Tri-Layer Polymer Actuators With Variable Dimensions, Rick Minato, Gursel Alici, Scott T. Mcgovern, Geoffrey M. Spinks Oct 2012

Tri-Layer Polymer Actuators With Variable Dimensions, Rick Minato, Gursel Alici, Scott T. Mcgovern, Geoffrey M. Spinks

Gursel Alici

The ability of conducting polymer actuators to convert electrical energy into mechanical energy is influenced by manyfactors ranging from the actuators physical dimensions to the chemical structure of the conducting polymer. In order toutilise these actuators to their full potential, it is necessary to explore and quantify the effect of such factors on theoverall actuator performance. The aim of this study is to investigate the effect of various geometrical characteristics suchas the actuator width and thickness on the performance of tri-layer polypyrrole (PPy) actuators operating in air, asopposed to their predecessors operating in an appropriate electrolyte. For a constant actuator …


Deformable Object Simulation With Poisson Equation, Yongmin Zhong, Bijan Shirinzadeh, Gursel Alici, Julian Smith Oct 2012

Deformable Object Simulation With Poisson Equation, Yongmin Zhong, Bijan Shirinzadeh, Gursel Alici, Julian Smith

Gursel Alici

This paper presents a new methodology for the deformation of soft objects by drawing an analogy between Poisson equation and elastic deformation. The potential energy stored in an elastic body as a result of a deformation caused by an external force is propagated among mass points by the Poisson equation. An improved Poisson model is developed for propagating the energy generated by the external force in a natural manner. A method is presented to derive the internal forces from the potential energy distribution. This proposed methodology not only deals with large-range deformations, but also accommodates both isotropic and anisotropic materials …


A Bio-Inspired Robotic Locomotion System Based On Conducting Polymer Actuators, Gursel Alici, Daniel Gunderson Oct 2012

A Bio-Inspired Robotic Locomotion System Based On Conducting Polymer Actuators, Gursel Alici, Daniel Gunderson

Gursel Alici

This paper presents the conceptual design and testing of a bio-inspired locomotion system activated through ionic-type conducting polymer actuators, which can operate both in dry and wet environments. The locomotion system is proposed for a mini autonomous crawling device for applications typified by pipe inspection, search, inspection and data gathering in confined spaces, which require mini-robotic systems. The locomotion system is based on the cilia, which has a simple planar bending motion. This type of motion can be provided by bending-type polymer actuators (one-end fixed and the other-end free cantilever beam). The actuators mounted on a printed circuit board and …


Robust Motion Tracking Control Of Piezoelectric Actuation Systems, Hwee Choo Liaw, Denny Oetomo, Bijan Shirinzadeh, Gursel Alici Oct 2012

Robust Motion Tracking Control Of Piezoelectric Actuation Systems, Hwee Choo Liaw, Denny Oetomo, Bijan Shirinzadeh, Gursel Alici

Gursel Alici

This paper proposes a robust control methodology for piezoelectric actuation systems to track specified motion trajectories. This is motivated by the search for an effective control strategy to deal with the problem of nonlinear behaviour in the piezoelectric actuation systems. The basic concept associated with this approach lies in the specification of a target performance and the formulation of a robust control scheme for the system to ensure the convergence of the position tracking error to zero in the presence of parametric uncertainties and hysteresis effect inclusive of other un-modelled disturbances. Stability of the control system is proven theoretically and …


A Review Of Localization Systems For Robotic Endoscopic Capsules, Trung Duc Than, Gursel Alici, Hao Zhou, Weihua Li Oct 2012

A Review Of Localization Systems For Robotic Endoscopic Capsules, Trung Duc Than, Gursel Alici, Hao Zhou, Weihua Li

Gursel Alici

Obscure gastrointestinal (GI) bleeding, Crohn disease, Celiac disease, small bower tumors, and other disorders that occur in the GI tract have always been challenging to be diagnosed and treated due to the inevitable difficulty in accessing such a complex environment within the human body. With the invention of wireless capsule endoscope, the next generation of the traditional cabled endoscope, not only a dream has come true for the patients who have experienced a great discomfort and unpleasantness caused by the conventional endoscopic method, but also a new research field has been opened to develop a complete miniature robotic device that …


Motion Tracking Control Of Piezo-Driven Flexure-Based Mechanism Based On Sliding Mode Strategy, Hwee Choo Liaw, Bijan Shirinzadeh, Julian Smith, Gursel Alici Oct 2012

Motion Tracking Control Of Piezo-Driven Flexure-Based Mechanism Based On Sliding Mode Strategy, Hwee Choo Liaw, Bijan Shirinzadeh, Julian Smith, Gursel Alici

Gursel Alici

This paper presents a motion tracking control methodology based on sliding mode strategy for a flexure-based micro/nano manipulator driven by a piezoelectric actuator. This control methodology is proposed for tracking of desired motion trajectories in the presence of uncertain system parameters, non-linearities including the hysteresis effect, and external disturbances in the control system. In this paper, a four-bar link is investigated and a lumped parameter dynamic model is established for the formulation of the proposed sliding mode motion control methodology. The convergence of the position tracking error to zero is assured by the approach in the presence of the aforementioned …


Model-Based Adaptive Control Of Piezoelectric Actuation Systems, Hwee Choo Liaw, Denny Oetomo, Bijan Shirinzadeh, Gursel Alici Oct 2012

Model-Based Adaptive Control Of Piezoelectric Actuation Systems, Hwee Choo Liaw, Denny Oetomo, Bijan Shirinzadeh, Gursel Alici

Gursel Alici

This paper proposes a model-based adaptive control methodology for piezoelectric actuation systems to follow specified motion trajectories. This is motivated by a search for an effective control strategy to deal with the problem of parametric uncertainties such as disturbance and hysteresis effects. The proposed adaptive law is formulated by combining a parameter compensator and a conventional PD feedback control for a system to drive its position tracking error converging to zero. The fundamental concept lies in the properties of a quasinatural potential function, which allows a saturated position error function in the control formulation. Implementation of the control law requires …


Optimal Area Covering Using Genetic Algorithms, Paulo A. Jimenez, Bijan Shirinzadeh, Ann Nicholson, Gursel Alici Oct 2012

Optimal Area Covering Using Genetic Algorithms, Paulo A. Jimenez, Bijan Shirinzadeh, Ann Nicholson, Gursel Alici

Gursel Alici

Path planning problems involve computing or finding a collision free path between two positions. A special kind of path planning is complete coverage path planning, where a robot sweeps all area of free space in an environment. There are different methods to cover the complete area; however, they are not designed to optimize the process. This paper proposes a novel method of complete coverage path planning based on genetic algorithms. In order to check the viability of this approach the optimal path is tested in a virtual environment. The simulation results confirm the feasibility of this method.


Special Class Of Positive Definite Functions For Formulating Adaptive Micro/Nano Manipulator Control, Hwee Choo Liaw, Denny Oetomo, Gursel Alici, Bijan Shirinzadeh Oct 2012

Special Class Of Positive Definite Functions For Formulating Adaptive Micro/Nano Manipulator Control, Hwee Choo Liaw, Denny Oetomo, Gursel Alici, Bijan Shirinzadeh

Gursel Alici

This paper presents a special class of positive definite functions for the formulation of adaptive control strategies, specifically in the research of an effective control algorithm for piezoelectric actuation systems in micro/nano manipulation. To deal with the control problems of unknown system parameters, nonlinear hysteresis effects, and disturbances in the piezoelectric actuation systems, an adaptive control methodology is proposed. Using the saturation function derived from a positive definite function to formulate the control methodology, the closed-loop system stability can be guaranteed. Furthermore, the control methodology is proposed to track a desired motion trajectory in position, velocity, and acceleration. In this …


Towards Improving Positioning Accuracy Of Conducting Polymer Actuators, Gursel Alici, Nam N. Huynh Oct 2012

Towards Improving Positioning Accuracy Of Conducting Polymer Actuators, Gursel Alici, Nam N. Huynh

Gursel Alici

Recently, there have been significant developments in conducting polymers, particularly in their synthesis and use as electromechanical actuators. This is mainly due to their many promising features including biocompatibility, high force to weight ratio, suitability to open loop control. On the other hand, they suffer from nonlinear problems such as hysteresis and creep. With this in mind, it is the aim of this study to evaluate the existence level of these nonlinearities and their mathematical modeling in order to improve the positioning accuracy of conducting polymer actuators. The polymer actuator considered in this study which has a symmetrical structure can …


A Simple And Cost-Effective Method For Fabrication Of Integrated Electronic-Microfluidic Devices Using A Laser-Patterned Pdms Layer, Ming Li, Shunbo Li, Jinbo Wu, Weijia Wen, Weihua Li, Gursel Alici Oct 2012

A Simple And Cost-Effective Method For Fabrication Of Integrated Electronic-Microfluidic Devices Using A Laser-Patterned Pdms Layer, Ming Li, Shunbo Li, Jinbo Wu, Weijia Wen, Weihua Li, Gursel Alici

Gursel Alici

We report a simple and cost-effective method for fabricating integrated electronic-microfluidic devices with multilayer configurations. A CO2 laser plotter was employed to directly write patterns on a transferred polydimethylsiloxane (PDMS) layer, which served as both a bonding and a working layer. The integration of electronics in microfluidic devices was achieved by an alignment bonding of top and bottom electrode-patterned substrates fabricated with conventional lithography, sputtering and lift-off techniques. Processes of the developed fabrication method were illustrated. Major issues associated with this method as PDMS surface treatment and characterization, thickness-control of the transferred PDMS layer, and laser parameters optimization were discussed, …


Contact State Determination For Robotic-Based Cylindrical Pair Height Adjustment Under Dynamic Conditions, Prasan I. De Waas Tilakaratna, Bijan Shirinzadeh, Gursel Alici Oct 2012

Contact State Determination For Robotic-Based Cylindrical Pair Height Adjustment Under Dynamic Conditions, Prasan I. De Waas Tilakaratna, Bijan Shirinzadeh, Gursel Alici

Gursel Alici

This paper investigates fine motion strategies associated with the height adjustment manipulations of a cylindrical pair which can be utilised in dynamic assembly and reconfigurable workholding systems. The outer link of the cylindrical pair is held by the end-effector of a 6DOF serial articulated robot. The environment which holds the inner link can be dynamic. Formulations capable of identifying the type of contact between the links and parameters vital for control purposes based on the force and torque data provided by a wrist mounted F/T sensor are established for a generic spatial case. Experimental results indicate that the established methodology …


Robust Control Framework For Piezoelectric Actuation Systems In Micro/Nano Manipulation, Hwee Choo Liaw, Denny Oetomo, Bijan Shirinzadeh, Gursel Alici Oct 2012

Robust Control Framework For Piezoelectric Actuation Systems In Micro/Nano Manipulation, Hwee Choo Liaw, Denny Oetomo, Bijan Shirinzadeh, Gursel Alici

Gursel Alici

Micro/nano manipulation has been identified as one of the key enabling technologies for many emerging challenges. Within this scope, piezoelectric actuators have played major roles in achieving the required nano-resolution motion. This paper proposes a robust control framework for piezoelectric actuation systems to follow specified motion trajectories. The basic concept associated with this methodology lies in the specification of a target performance and the robust control scheme formulation for piezoelectric actuation systems to ensure the convergence of the position tracking error to zero. This control methodology is attractive as its implementation requires only the knowledge of the estimated system parameters …


A Continuously-Stable Linear Actuation Based On Bending Type Artificial Muscles, Rahim Mutlu, Gursel Alici Oct 2012

A Continuously-Stable Linear Actuation Based On Bending Type Artificial Muscles, Rahim Mutlu, Gursel Alici

Gursel Alici

Electroactive polymer actuators, also known as artificial muscles, can operate both in wet and dry media under as small as 1 Volt potential difference. This paper reports on a multi-stable linear actuation mechanism articulated with artificial muscles. Kinematic and finite element analyses of the mechanism are studied to demonstrate the feasibility of the mechanism. Experiments were conducted on a real mechanism articulated with a multiple number (4 or 8) of electroactive polymer actuators, which had the dimensions of 12×2×0.17mm. The numerical and experimental results demonstrate that the angular displacement of the artificial muscles is accurately transformed into a rectilinear motion …


Enhanced Stiffness Modeling, Identification And Characterization For Robot Manipulators, G. Alici, B. Shirinzadeh Mar 2012

Enhanced Stiffness Modeling, Identification And Characterization For Robot Manipulators, G. Alici, B. Shirinzadeh

Gursel Alici

This paper presents the enhanced stiffness modeling and analysis of robot manipulators, and a methodology for their stiffness identification and characterization. Assuming that the manipulator links are infinitely stiff, the enhanced stiffness model contains: 1) the passive and active stiffness of the joints and 2) the active stiffness created by the change in the manipulator configuration, and by external force vector acting upon the manipulator end point. The stiffness formulation not accounting for the latter is known as conventional stiffness formulation, which is obviously not complete and is valid only when: 1) the manipulator is in an unloaded quasistatic configuration …