Electrical and Electronic Engineering - Journal Articles
http://hdl.handle.net/10468/130
2016-02-06T00:19:34ZNonlinear analytical modeling and characteristic analysis of symmetrical wire beam based composite compliant parallel modules for planar motion
http://hdl.handle.net/10468/1526
Nonlinear analytical modeling and characteristic analysis of symmetrical wire beam based composite compliant parallel modules for planar motion
Hao, Guangbo; Kong, Xianwen
This paper mainly deals with the nonlinear analytical modeling and characteristics analysis of two types of composite multi-beam modules for planar motion to enable rapid analysis and design synthesis. Each type of composite multi-beam module consists of identical, uniform and parallel wire beams, distributing uniformly along circle(s), with symmetrical cross sections. Analytical models of basic multi-beam modules with all beams uniformly spaced around a circle are firstly revisited. Analytical and nonlinear load-displacement equations are derived for the composite multi-beam modules, each of which is composed of two basic multi-beam modules with the same type connected either serially or in parallel. Finite element analysis (FEA) is carried out to compare and verify the present analytical models. Detailed characteristics analysis and comparisons are conducted to compare three types of compliant six-beam modules whose twisting rotations are well constrained. These analytical results are capable of capturing some key quantitative nonlinear characteristics, such as kinematic effects, load-stiffening effect and nonlinear twisting stiffness, and can promote the design and analytical modeling of resulting compliant parallel manipulators composed of compliant multi-beam modules. In addition, the nonlinear analytical models of other variations of parallel double multi-beam modules are derived.
2014-07-01T00:00:00ZA 2-legged XY parallel flexure motion stage with minimised parasitic rotation
http://hdl.handle.net/10468/1527
A 2-legged XY parallel flexure motion stage with minimised parasitic rotation
Hao, Guangbo
XY compliant parallel manipulators (aka XY parallel flexure motion stages) have been used as diverse applications such as atomic force microscope scanners due to their proved advantages such as eliminated backlash, reduced friction, reduced number of parts and monolithic configuration. This paper presents an innovative stiffness centre based approach to design a decoupled 2-legged XY compliant parallel manipulator in order to better minimise the inherent parasitic rotation and have a more compact configuration. This innovative design approach makes all of the stiffness centres, associated with the passive prismatic (P) modules, overlap at a point that all of the applied input forces can go through. A monolithic compact and decoupled XY compliant parallel manipulator with minimised parasitic rotation is then proposed using the proposed design approach based on a 2-PP kinematically decoupled translational parallel manipulator. Its loadâ€“displacement and motion range equations are derived, and geometrical parameters are determined for a specified motion range. Finite element analysis comparisons are also implemented to verify the analytical models with analysis of the performance characteristics including primary stiffness, cross-axis coupling, parasitic rotation, input and output motion difference and actuator nonisolation effect. Compared with the existing XY compliant parallel manipulators obtained using 4-legged mirror-symmetric constraint arrangement, the proposed XY compliant parallel manipulators based on stiffness centre approach mainly benefits from fewer legs resulting in reduced size, simpler modelling as well as smaller lost motion. Compared with existing 2-legged designs with the conventional arrangement, the present design has smaller parasitic rotation, which has been proved from the finite element analysis results.
2014-03-01T00:00:00ZDesign of 3-legged XYZ compliant parallel manipulators with minimised parasitic rotations
http://hdl.handle.net/10468/1515
Design of 3-legged XYZ compliant parallel manipulators with minimised parasitic rotations
Hao, Guangbo; Li, Haiyang
This paper deals with the design of 3-legged distributed-compliance XYZ compliant parallel manipulators (CPMs) with minimised parasitic rotations, based on the kinematically decoupled 3-PPPRR (P: prismatic joint, and R: revolute joint) and 3-PPPR translational parallel mechanisms (TPMs). The designs are firstly proposed using the kinematic substitution approach, with the help of the stiffness center (SC) overlapping based approach. This is done by an appropriate embedded arrangement so that all of the SCs associated with the passive compliant modules overlap at the point where all of the input forces applied at the input stages intersect. Kinematostatic modelling and characteristic analysis are then carried out for the proposed large-range 3-PPPRR XYZ CPM with overlapping SCs. The results from finite element analysis (FEA) are compared to the characteristics found for the developed analytical models, as are experimental testing results (primary motion) from the prototyped 3-PPPRR XYZ CPM with overlapping SCs. Finally, issues on large-range motion and dynamics of such designs are discussed, as are possible improvements of the actuated compliant P joint. It is shown that the potential merits of the designs presented here include a) minimised parasitic rotations by only using three identical compliant legs; b) compact configurations and small size due to the use of embedded designs; c) approximately kinematostatically decoupled designs capable of easy controls; and d) monolithic fabrication for each leg using existing planar manufacturing technologies such as electric discharge machining (EDM).
2014-03-01T00:00:00ZA powerful visualization technique for electricity supply and demand at industrial sites with combined heat and power and wind generation
http://hdl.handle.net/10468/1459
A powerful visualization technique for electricity supply and demand at industrial sites with combined heat and power and wind generation
Hanrahan, Brian Leif; Lightbody, Gordon; Staudt, Lawrence; Leahy, Paul G.
The combination of wind generation and combined heat and power (CHP) on an industrial site brings significant design and operational challenges. The stochastic nature of wind power affects the flows of electricity imported and exported to and from the site. Economies of scale favor larger wind turbines, but at the same time it is also desirable to minimize the amount of electricity exported from the site to avoid incurring increased network infrastructure usage charges. Therefore the optimum situation is to maximize the proportion of the site load served by on-site generation. This paper looks at a visualization technique for power flows on an industrial site, which can be used to size on-site generators. The technique is applied to a test case, demonstrating how a simple combined heat and power control scheme can support the integration of on-site wind power. The addition of such CHP control has a small impact on the CHP unit but can greatly increase the proportion of wind generation consumed on-site. This visualization technique allows the comparison of different generation mixes and control schemes in order to arrive at the optimal mix from a technical and economic viewpoint.
2014-03-01T00:00:00Z