This page has only limited features, please log in for full access.
The application scope of unmanned aerial vehicles (UAVs) is increasing along with commensurate advancements in performance. The hybrid quadrotor vertical takeoff and landing (VTOL) UAV has the benefits of both rotary-wing aircraft and fixed-wing aircraft. However, the vehicle requires a robust controller for takeoff, landing, transition, and hovering modes because the aerodynamic parameters differ in those modes. We consider a nonlinear observer-based backstepping controller in the control design and provide stability analysis for handling parameter variations and external disturbances. We carry out simulations in MATLAB Simulink which show that the nonlinear observer contributes more to robustness and overall closed-loop stability, considering external disturbances in takeoff, hovering and landing phases. The backstepping controller is capable of decent trajectory-tracking during the transition from hovering to level flight and vice versa with nominal altitude drop.
Nihal Dalwadi; Dipankar Deb; Mangal Kothari; Stepan Ozana. Disturbance Observer-Based Backstepping Control of Tail-Sitter UAVs. Actuators 2021, 10, 119 .
AMA StyleNihal Dalwadi, Dipankar Deb, Mangal Kothari, Stepan Ozana. Disturbance Observer-Based Backstepping Control of Tail-Sitter UAVs. Actuators. 2021; 10 (6):119.
Chicago/Turabian StyleNihal Dalwadi; Dipankar Deb; Mangal Kothari; Stepan Ozana. 2021. "Disturbance Observer-Based Backstepping Control of Tail-Sitter UAVs." Actuators 10, no. 6: 119.
Maglev transportation system is become a hot topic for researchers because of the distinctive advantages, such as frictionless motion, low power consumption, less noise, and being environmentally friendly. The maglev transportation system’s performance gets sufficiently influenced by the control method and the magnetic levitation system’s dynamic performance, which is a critical component of the maglev transportation system. The Magnetic Levitation System (MLS) is a group of unstable, nonlinear, uncertain, and electromagnetically coupled practical application. Control objective of this study is to design a position stabilizing control strategy for Magnetic Levitation system under extreme uncertain parametric conditions using a reference model governed by a reference stabilizer and nonlinear adaptive control structure. After successful tuning the reference stabilizer with and without time-varying payload disturbance, the tracking-error dynamics are obtained in the presence of both matched and mismatched types of parametric uncertainties. Next, the close-loop stability theorem is formulated for Lyapunov stability analysis to get the design constraints, parameter update laws, and adaptive control law. Numerical simulations performed for a high range of parametric violations check the control design’s efficacy. The performance robustness gets confirmed by comparing the results with the nonlinear control approach. The MLS gets performance recovery and settles within safe limits in few seconds using the proposed methodology. However, the nonlinear controller faces permanent failure in stabilizing the MLS.
Nihal Dalwadi; Dipankar Deb; S. Muyeen. A Reference Model Assisted Adaptive Control Structure for Maglev Transportation System. Electronics 2021, 10, 332 .
AMA StyleNihal Dalwadi, Dipankar Deb, S. Muyeen. A Reference Model Assisted Adaptive Control Structure for Maglev Transportation System. Electronics. 2021; 10 (3):332.
Chicago/Turabian StyleNihal Dalwadi; Dipankar Deb; S. Muyeen. 2021. "A Reference Model Assisted Adaptive Control Structure for Maglev Transportation System." Electronics 10, no. 3: 332.