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Full-Text Articles in Engineering
Modelling Of Polypyrrole Actuators, Mehrdad Bahrami Samani, Geoffrey Spinks, Philip Whitten, Christopher Cook
Modelling Of Polypyrrole Actuators, Mehrdad Bahrami Samani, Geoffrey Spinks, Philip Whitten, Christopher Cook
Christopher Cook
Conducting polymers (CP) are a promising area in the field of micro actuators, and have potential applications in micro robotics. Their properties are modelled as having an electro-chemical active component and a passive viscoelastic component. Methods exist to model the passive component as a configuration of springs and dashpots and the electro-active effects as a strain generator. Typically, the strain is assumed to be proportional to the charge transferred, and the two components are assumed to be independent. We show that there is a significant interaction between the two components for polypyrrole actuators, by observing the dynamic elastic modulus whilst …
Robust Adaptive Control For Industrial Robots - A Decentralized System Method, M Liu, Christopher Cook
Robust Adaptive Control For Industrial Robots - A Decentralized System Method, M Liu, Christopher Cook
Christopher Cook
An adaptive control approach is presented for the tracking control of industrial robots. The approach utilizes the fact that a robot model can be described by equations that are linear in the system's unknown parameters. Taking uncertainties into account, the resulting controller has the property of robustness. The proof of stability and analytical results of the boundness of position tracking errors are given. By introducing filter operations in state measurements, the approach avoids the difficulty of measuring the accelerations of the robots' actuators. Simulation results are also presented
Comparison Of Rotary Valve And Blowtank Feed Rate Capacities, David Hastie, Peter Wypych, Ian Frew, Christopher Cook
Comparison Of Rotary Valve And Blowtank Feed Rate Capacities, David Hastie, Peter Wypych, Ian Frew, Christopher Cook
Christopher Cook
Rotary valves and blowtanks are widely used in industry for the pneumatic conveying of products, each having their pros and cons depending on the required application. This paper aims to show the differing results that can be obtained when conveying a product through a common pipeline using either a drop-through rotary valve or a bottom discharge blowtank. The rotary valve system has a number of issues, the main one being air leakage effects, whereas the blowtank system does not as it is an enclosed unit. The results of these experiments showed dramatic differences in product tonnage.
Dynamic Behaviour Of A Scara Robot With Links Subjected To Different Velocity Trajectories, Christopher Cook, M Ibrahim, A Tieu
Dynamic Behaviour Of A Scara Robot With Links Subjected To Different Velocity Trajectories, Christopher Cook, M Ibrahim, A Tieu
Christopher Cook
The dynamics of a mechanical manipulator have the inherent characteristics of being highly non-linear and strongly coupled due to the interaction of the inertial, centripetal, coriolis and gravitational forces. These characteristics produce difficulties in predicting the dynamic behaviour of a given manipulator's structure. These interactive forces depend largely on the geometrical configuration and operational conditions of a manipulator. Therefore, it is essential to investigate the dynamics behaviour under different conditions in order to obtain an optimal design. This paper presents a study of the dynamics behaviour of a robot's arm with particular reference to the mechanical manipulator being designed by …
Mechanical Performance Of Ppy Helix Tube Microactuator, Mehrdad Bahrami Samani, Geoffrey Spinks, Christopher Cook
Mechanical Performance Of Ppy Helix Tube Microactuator, Mehrdad Bahrami Samani, Geoffrey Spinks, Christopher Cook
Christopher Cook
Conducting polymer actuators with favourable properties such as linearity, high power density and compliance are of increasing demand in micro applications. These materials generate forces over two times larger than produced by mammalian skeletal muscles. They operate to convert electro chemical energy to mechanical stress and strain. On the other hand, the application of conducting polymers is limited by the lack of a full description of the relation between four essential parameters: stress, strain, voltage and current. In this paper, polypyrrole helix tube micro actuator mechanical characteristics are investigated. The electrolyte is propylene carbonate and the dopant is TBA. PF6. …
Improved Positional Accuracy Of Robots With High Nonlinear Friction Using A Modified Impulse Controller, Stephen Van Duin, Christopher Cook, Zheng Li, Gursel Alici
Improved Positional Accuracy Of Robots With High Nonlinear Friction Using A Modified Impulse Controller, Stephen Van Duin, Christopher Cook, Zheng Li, Gursel Alici
Christopher Cook
This paper presents a modified impulse controller to improve the steady state positioning of a SCARA robot having characteristics of high nonlinear friction. A hybrid control scheme consisting of a conventional PID part and an impulsive part is used as a basis to the modified controller. The impulsive part uses short width torque pulses to provide small impacts of force to overcome static fiction and move a robot manipulator towards its reference position. It has been shown that this controller can greatly improve a robot’s accuracy in position tracking. However, the system in attempting to reach steady state will inevitably …
Postgraduate And Undergraduate Mechatronics' Courses At The University Of Wollongong, C. Cook, Fazel Naghdy, F. De Boer
Postgraduate And Undergraduate Mechatronics' Courses At The University Of Wollongong, C. Cook, Fazel Naghdy, F. De Boer
Christopher Cook
This paper outlines the University's involvement with industry based manufacturing projects, and how this has lead to the recent establishment of postgraduate and undergraduate mechatronics degrees. The nature of the industrial projects is described with examples of specific problems, test equipment and experimental rigs given. This work can be used to explain the reasons for the design of the mechatronics courses at Wollongong. A new teaching methodology particularly suitable for mechatronic's education is also discussed.
Characterisation And Bending Modeling Of Conducting Polymer Actuators For Use In Micro/Nano Manipulation, G. Alici, B. Mui, C. Cook
Characterisation And Bending Modeling Of Conducting Polymer Actuators For Use In Micro/Nano Manipulation, G. Alici, B. Mui, C. Cook
Christopher Cook
As research efforts towards making functional micro/nano robotics system gather more momentum, there is an increasing need for new actuators that can not only be suitable to miniaturization, but also be free from sliding and rolling elements so that they can generate a motion resolution and accuracy in a submicron range. Conducting polymer actuators have many features to satisfy such a strict requirements. Before introducing them to the micro/nano robotics world, it is necessary to investigate into their actuation mechanism and the smallest displacement they can generate. In this paper, we report on the characterization and modelling of a strip-type …