Current Issue : January - March Volume : 2020 Issue Number : 1 Articles : 5 Articles
Asound source localization device based on amultimicrophone array with the rectangular pyramid structure is proposed for mobile\nrobot in some indoor applications. Firstly, a time delay estimation method based on the cross-power spectral phase algorithm\nand a fast search strategy of peak value based on the geometric distribution of microphones are developed to estimate the sound\npropagation delay differences between two microphones. Moreover, a rejection strategy is presented to evaluate the correctness of\nthe delay difference values.And then, the deviceâ??s geometric equations based on the time-spacemapping relationship are established\nto calculate the position of the sound source. For fast solving the equations, themultimicrophone array space is divided into several\nsubspaces to narrow the solution range, and Newton iteration algorithm is introduced to solve the equations, while its solution\nis evaluated by an evaluation mechanism based on coordinate thresholds. Finally, some experiments are carried out to verify the\nperformance of the device, of which the results show that the device can achieve sound source localization with a high accuracy....
Compared with the tailless flapping wing micro air vehicle (FMAV), the tailed FMAV has a simpler structure and is easier to\ncontrol. However, although biplane FMAVs with tails have been used for flight control in practice for a long time, a theoretical\nmodel of the tailed FMAV has not previously been established. In this paper, we report modeling of the longitudinal dynamics of\na tailed biplane FMAV using the Newton-Euler equations. In this study, the vehicle was trimmed and linearized near its hovering\nequilibrium, assuming small disturbances.Then the stability of the hovering FMAV was analyzed with a modal analysis method.\nA state feedback controller was synthesized to stabilize the disturbance. Finally, we investigated the flight control of the tailed\nbiplane FMAVwith different control signals. Our results show that the natural-motionmode determines the oscillation divergence\ncharacteristics of the tailed FMAV, amode that can be suppressed with the state feedback controller by real-timemodulation of the\ntail. The tail can also be used to achieve different flight modes with different control-signal functions. The tailed FMAV cruises in\na line when the tail is controlled with a step function and spirals in an elliptical trajectory in the longitudinal plane when the tail is\ncontrolled by a sinusoidal function. Our longitudinal- dynamics model provides an analytical basis for further dynamic analyses of\nthe tailed FMAV, as well as the corresponding controller synthesis. Moreover, the proposed attitude stabilization and flight control\nschemes for the vehicle near hovering provide a basis for developing practical uses of the tailed FMAV....
A novel iterative learning control (ILC) algorithm for a two-wheeled self-balancing mobile robot with time-varying, nonlinear, and\nstrong-coupling dynamics properties is presented to resolve the trajectory tracking problem in this research. A kinematics model\nand dynamic model of a two-wheeled self-balancing mobile robot are deduced in this paper, and the combination of an openclosed-\nloop PD-ILC law and a variable forgetting factor is presented.The open-closed-loop PD-ILC algorithm adopts current and\npast learning items to drive the state variables and input variables, and the output variables converge to the bounded scope of their\ndesired values. In addition, introducing a variable forgetting factor can enhance the robustness and stability of ILC. Numerous\nsimulation and experimental data demonstrate that the proposed control scheme has better feasibility and effectiveness than the\ntraditional control algorithm....
This paper presents our work over the last decade in developing functional microrobotic\nsystems, which include wireless actuation of microrobots to traverse complex surfaces, addition of\nsensing capabilities, and independent actuation of swarms of microrobots. We will discuss our\nwork on the design, fabrication, and testing of a number of different mobile microrobots that\nare able to achieve these goals. These microrobots include the microscale magnetorestrictive\nasymmetric bimorph microrobot (microMAB), our first attempt at magnetic actuation in the microscale;\nthe microscale tumbling microrobot (microTUM), our microrobot capable of traversing complex surfaces\nin both wet and dry conditions; and the micro-force sensing magnetic microrobot (microFSMM), which is\ncapable of real-time micro-force sensing feedback to the user as well as intuitive wireless actuation.\nAdditionally, we will present our latest results on using local magnetic field actuation for independent\ncontrol of multiple microrobots in the same workspace for microassembly tasks....
In this work, a controller design technique called linear algebra based controller (LABC) is presented. The controller is\nobtained following a systematic procedure that is summarized in this work. In addition, the influence of additive uncertainty\non the tracking error is analyzed, and a solution using integrators is proposed. A mobile robot is used as a benchmark to test\nthe performance of the proposed algorithms. In addition, implementation to other systems such as marine vessel is referenced.\nIn this work, the design of controllers in continuous and discrete time is included and experimental and simulation\nresults are shown in a Pioneer 3AT mobile robot. Comparisons are also shown with other controllers proposed in\nthe literature....
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