Current Issue : January - March Volume : 2015 Issue Number : 1 Articles : 7 Articles
A parametric learning based robust iterative learning control (ILC) scheme is applied to the time varying delay multiple-input and\nmultiple-output (MIMO) linear systems. The convergence conditions are derived by using the H? and linear matrix inequality\n(LMI) approaches, and the convergence speed is analyzed as well. A practical identification strategy is applied to optimize the\nlearning laws and to improve the robustness and performance of the control system.Numerical simulations are illustrated to validate\nthe above concepts....
A coupled system of an ordinary differential equation (ODE) and a heat partial differential equation (PDE) with spatially varying coefficients is discussed. By using the PDE back stepping method, the state-feedback stabilizing controller is explicitly constructed with the assumptions ?(x) ? P[x]n and ?(x) ? C? [0, l], respectively.The closed-loop system is proved to be exponentially stable by this controller. A simulation example is presented to illustrate the effectiveness of the proposed method....
With the fast development of social economy, the competition between enterprises in construction projects becomes more and\nmore serious. The cost control method is proposed to the bidding process of enterprises based on the gray system forecast. At the\nsame time, the cost control software is also constructed to the bidding process of enterprises. Experimental results suggest that the\nproposed approach is feasible and correct...
We address an iterative learning control (ILC) method for overcoming initial value problem caused by local convergence methods.\nIntroducing a feedback recursive form of tracking errors into iterative learning law, this algorithm can avoid a crude linear\napproximation to nonlinear plants to reach global convergence property. The algorithm�s structure is entirely illustrated. Under\nassumptions, it is guaranteed that tracking errors of the closed-loop system converge to zero. Besides, we discuss the roles\nof parameters in iterative learning law for algorithm realization, and a nonlinear case study is presented to demonstrate the\neffectiveness and tracking performance of the proposed algorithm...
Considering the guidance problem of relative motion of missile target without the dynamic characteristics of missile autopilot in\nthe interception planar, non-homogeneous disturbance observer is applied for finite-time estimation with respect to the target\nmaneuvering affecting the guidance performance. Two guidance laws with finite-time convergence are designed by using a\nfast power rate reaching law and the prescribed sliding variable dynamics. The non singular terminal sliding mode surface is\nselected to improve dynamic characteristics of missile autopilot. Furthermore, the finite-time guidance law with dynamic delay\ncharacteristics is designed for the target maneuvering through adopting variable structure dynamic compensation. The simulation\nresults demonstrate that, for different target maneuvering, the proposed guidance laws can restrain the sliding mode chattering\nproblem effectively and make the missile hit the maneuvering target quickly and accurately with condition of corresponding\nassumptions....
This paper focuses on the problem of visual servo grasping of household objects for nonholonomic mobile manipulator. Firstly, a\nnew kind of artificial object mark based onQR (Quick Response) Code is designed, which can be affixed to the surface of household\nobjects. Secondly, after summarizing the vision-based autonomous mobile manipulation system as a generalized manipulator, the\ngeneralized manipulator�s kinematic model is established, the analytical inverse kinematic solutions of the generalized manipulator\nare acquired, and a novel active vision based camera calibration method is proposed to determine the hand-eye relationship. Finally,\na visual servo switching control law is designed to control the service robot to finish object grasping operation. Experimental results\nshow that QR Code-based artificial object mark can overcome the difficulties brought by household objects� variety and operation\ncomplexity, and the proposed visual servo scheme makes it possible for service robot to grasp and deliver objects efficiently....
Electrohydrostatic actuator (EHA) is a new actuator for next generation aircraft actuation system. This actuator is essentially a\nnonlinear system; response speed and accuracy are the main consideration.We use sliding mode control for this nonlinear system\nin this paper. The variable structure filter (VSF) is introduced to obtain the unmeasured states. Derivation of the VSF gain based\non the reaching law is presented in this paper. To improve the response speed and accuracy, a nonlinear function is introduced to\nconstruct the nonlinear sliding surface using the estimated states generated by VSF. Simulation results show that low settling time\nand quick response are obtained by using the nonlinear sliding surface....
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