Current Issue : April - June Volume : 2017 Issue Number : 2 Articles : 6 Articles
This paper considers the robust and adaptive nonsingular terminal sliding mode (NTSM) control for a class of second-order\nuncertain systems. First, a new fast NTSM was proposed which had global fast convergence rate in the sliding phase. Then, a\nnew form of robust NTSM controller was designed to handle a wider class of second-order uncertain systems. Moreover, an\nexponential-decline switching gain was introduced for chattering suppression. After that, a double sliding surfaces control scheme\nwas constructed to combine the NTSM control with the adaptive technique.The benefit is that a strict demonstration can be given\nfor the stagnation problem in the stability analysis of NTSM. Finally, a case study for tracking control of a variable-length pendulum\nwas performed to verify the proposed controllers....
In a plate rolling production line, thermomechanically controlled processing is critical for plate quality. In this paper, a set of\nintermediate cooling equipment of a two-stand plate mill with super density nozzles, medium pressure, and small flow is developed.\nBased on a simplified dynamic model, a cooling control scheme with combined feedforward, feedback, and adaptive algorithms is\nput forward.The new controlled rolling process and the highly efficient control system improve the controlled rolling efficiency by\nan average of 17.66%. The proposed intermediate cooling system can also effectively inhibit the growth of austenite grain, improve\nthe impact toughness and yield strength of Q345B steel plate, reduce the formation of secondary oxide scale on the plate surface\nand the chromatic aberration of the plate surface, and greatly improve the surface quality of the steel plate....
This paper presents mathematical modelling and control of a two-wheeled single-seat vehicle. The design of the vehicle is inspired by the Personal Urban Mobility and Accessibility (PUMA) vehicle developed by General Motors�® in collaboration with Segway�®. The body of the vehicle is designed to have two main parts. The vehicle is activated using three motors; a linear motor to activate the upper part in a sliding mode and two DC motors activating the vehicle while moving forward/backward and/or manoeuvring. Two stages proportional-integral-derivative (PID) control schemes are designed and implemented on the system models. The state space model of the vehicle is derived from the linearized equations. Controller based on the Linear Quadratic Regulator (LQR) and the pole placement techniques are developed and implemented. Further investigation of the robustness of the developed LQR and the pole placement techniques is emphasized through various experiments using an applied impact load on the vehicle....
This paper is about the nonfragile...
We consider a continuous linear time invariant system with ellipsoidal parametric uncertainty structured into subsystems. Since the\ndesign of a local controller uses only information on a subsystemand its neighbours, we combine the plug and play idea and robust\ndistributed control to propose one distributed control strategy for linear system with ellipsoidal parametric uncertainty. Firstly\nfor linear system with ellipsoidal parametric uncertainty, a necessary and sufficient condition for robust state feedback control is\nproposed by means of linear matrix inequality. If this necessary and sufficient condition is satisfied, this robust state feedback gain\nmatrix can be easily derived to guarantee robust stability and prescribed closed loop performance. Secondly the plug and play idea\nis introduced in the design process. Finally by one example of aircraft flutter model parameter identification, the efficiency of the\nproposed control strategy can be easily realized....
The hysteresis characteristics resulted from piezoelectric actuators (PAs) and the\nresidual vibration in the rapid positioning of a two-dimensional piezo-driven microdisplacement\nscanning platform (2D-PDMDSP) will greatly affect the positioning\naccuracy and speed. In this paper, in order to improve the accuracy and speed of the\npositioning and restrain the residual vibration of 2D-PDMDSP, firstly, Utilizing an\nonline hysteresis observer based on the asymmetrical Bouc-Wen model, the PA with\nthe hysteresis characteristics is feedforward linearized and can be used as a linear actuator;\nsecondly, zero vibration and derivative shaping (ZVDS) technique is used to eliminate\nthe residual vibration of the 2D-PDMDSP; lastly, the robust model reference adaptive\n(RMRA) control for the 2D-PDMDSP is proposed and explored. The rapid control\nprototype of the RMRA controller combining the proposed feedforward linearization\nand ZVDS control for the 2D-PDMDSP with rapid control prototyping technique\nbased on the real-time simulation system is established and experimentally tested,\nand the corresponding controlled results are compared with those by the PID control\nmethod. The experimental results show that the proposed RMRA control method can\nsignificantly improve the accuracy and speed of the positioning and restrain the residual\nvibration of 2D-PDMDSP....
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