Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Abstract:In this paper, a new dynamic model for continuum robot manipulators is derived. The dynamic model is developed based on the geometric model of extensible continuum robot manipulators with no torsional effects. The development presented in this paper is an extension of the dynamic model proposed in [19] (by Mochiyama and Suzuki) to include a class of extensible continuum robot manipulators. Numerical simulation results are presented for a planar 3-link extensible continuum robot manipulator.

SUMMARYIn this paper, adaptive control of kinematically redundant robot manipulators is considered. An end-effector tracking controller is designed and the manipulator's kinematic redundancy is utilized to integrate a general sub-task controller for self-motion control. The control objectives are achieved by designing a feedback linearizing controller that includes a least-squares estimation algorithm to compensate for the parametric uncertainties. Numerical simulation results are presented to show the validity of the proposed controller.

Abstract:In this paper, the dynamic model for planar continuum manipulators that was presented in our previous work is extended to include new terms reflecting the effects of potential energy. First the gravitational potential energy of the manipulator is derived. Then, the elastic potential energy of the manipulator is derived for both bending and extension. Finally, the effects of the total potential energy are included in the dynamic model. Numerical simulation results are presented for a planar 3-section extensible continuum robot manipulator. The results show a much stronger match to physical continuum robots than with previously available models.

Abstract:In this study, an optimum seeking-based robust non-linear controller is proposed to maximise wind energy captured by variable speed wind turbines at low-to-medium wind speeds. The proposed strategy simultaneously controls the blade pitch angle and tip-speed ratio, through the turbine rotor angular speed, to an optimal point at which the power coefficient, and hence the wind turbine efficiency, is maximum. The optimal points are given to the controller by an optimisation algorithm that seeks the unknown optimal blade pitch angle and rotor speed. The control method allows for aerodynamic rotor power maximisation without exact knowledge of the wind turbine model. A representative numerical simulation is presented to show that the wind turbine can be accurately controlled to achieve maximum energy capture.

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Abstract: Past research efforts have focused on the end-effector tracking control of redundant robots because of their increased dexterity over their nonredundant counterparts. This work utilizes an adaptive full-state feedback quaternion based controller developed in [5] and focuses on the design of a general sub-task controller. This sub-task controller does not affect the position and orientation tracking control objectives, but instead projects a preference on the configuration of the manipulator based on sub-task objectives such as the following: singularity avoidance, joint limit avoidance, bounding the impact forces, and bounding the potential energy.

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Abstract-In recent years, controller formulations using robust integral of sign of error (RISE) type feedback have been successfully applied to a variety of nonlinear dynamical systems. The drawback of these type of controllers however, are (i) the need of prior knowledge of the upper bounds of the system uncertainties and (ii) the absence of a proper gain tuning methodology. To tackle the aforementioned weaknesses, in our previous work [1] we have presented a RISE formulation with a time-varying compensation gain to cope for the need of upper bound of the uncertain system. In this study, we have extended our previous design to obtain a fully self tuning RISE feedback formulation. Lyapunov based arguments are applied to prove overall system stability and extensive numerical simulation studies are presented to illustrate the performance of the proposed method.

Abstract-In this paper, a new robust integral of signum of error (RISE) feedback type controller is designed for a class of uncertain nonlinear systems. Unlike the previous versions of RISE feedback type controllers, the proposed controller does not require prior knowledge of upper bounds of the vector containing the uncertainties of the dynamical system plus desired system dynamics (and their derivatives) for the control gain selection. The aforementioned enhancement is made possible via the design of a time-varying compensation gain as opposed to a constant gain used in previous RISE feedback type controllers. Asymptotic stability of the error signals and the boundedness of the closed-loop system signals are ensured via Lyapunov based arguments. Numerical simulation studies are presented to illustrate the viability of the proposed method.