The paper proposes a nonlinear optimal control approach for the model of the vertical take off and landing(VTOL)aircraft.This aerial drone receives as control input a directed thrust,as well as forces acting on its wi...The paper proposes a nonlinear optimal control approach for the model of the vertical take off and landing(VTOL)aircraft.This aerial drone receives as control input a directed thrust,as well as forces acting on its wing tips.The latter forces are not perpendicular to the body axis of the drone but are tilted by a small angle.The dynamic model of the VTOL undergoes ap-proximate linearization with the use of Taylor series expansion around a temporary operating point which is recomputed at each iteration of the control method.For the approximately linearized model,an H-infinity feedback controller is designed.The linearization procedure relies on the computation of the Jacobian matrices of the state-space model of the VTOL aircraft.The proposed control method stands for the solution of the optimal control problem for the nonlinear and multivariable dynamics of the aerial drone,under model uncertainties and external per-turbations.For the computation of the contollr's feedback gains,an algebraic Riccati equation is solved at each time-step of the control method.The new nonlinear optimal control approach achieves fast and accurate tracking for all state variables of the VTOL aircnaft,under moderate variations of the control inputs.The stability properties of the control scheme are proven through Lyapunov analysis.展开更多
Attitude control and stabilization of micro-satellites is a nontrivial problem due to the highly nonlinear and multivariable structure of the satellites'state-space model.In this paper,a novel nonlinear optimal(H-...Attitude control and stabilization of micro-satellites is a nontrivial problem due to the highly nonlinear and multivariable structure of the satellites'state-space model.In this paper,a novel nonlinear optimal(H-infinity)control approach is developed for this control problem.The dynamic model of the satellite's attitude dynamics undergoesfirst approximate linearization around a temporary operating point which is updated at each iteration of the control algorithm.The linearization process relies on first-order Taylor series expansion and on the computation of the Jacobian matrices of the state-space model of the satellite's attitude dynamics.For the approximately linearized description of the satellite's attitude a stabilizing H-infinity feedback controller is designed.To compute the controller's feedback gains,an algebraic Riccati equation is solved at each time-step of the control method.The stability properties of the control scheme are proven through Lyapunov analysis.It is also demonstrated that the control method retains the advantages of linear optimal control that is fast and accurate tracking of the reference setpoints under moderate variations of the control inputs.展开更多
A non-linear optimal(H-infinity)control approach is proposed for the dynamic model of multi-degree-of-freedom(DOF)electro-hydraulic robotic manipulators.Control of electro-hydraulic manipulators is a non-trivial probl...A non-linear optimal(H-infinity)control approach is proposed for the dynamic model of multi-degree-of-freedom(DOF)electro-hydraulic robotic manipulators.Control of electro-hydraulic manipulators is a non-trivial problem because of their non-linear and multi-variable dynamics.In this study,the considered robotic system consists of a multi-link robotic manipulator that receives actuation from rotary electro-hydraulic drives.The article's approach relies first on approximate linearisation of the state-space model of the electro-hydraulic manipulator,according to first-order Taylor series expansion and the computation of the related Jacobian matrices.For the approximately linearised model of the manipulator,a stabilising H-infinity feedback controller is designed.To compute the controller's gains,an algebraic Riccati equation is solved at each time-step of the control algorithm.The global stability properties of the control scheme are proven through Lyapunov analysis.The proposed control method retains the advantages of typical optimal control,i.e.fast and accurate tracking of the reference setpoints under moderate variations of the control inputs.展开更多
The overuse and misuse of antibiotics has become a major problem for public health.People become resistant to antibiotics and because of this the anticipated therapeutic effect is never reached.In-hospital infections ...The overuse and misuse of antibiotics has become a major problem for public health.People become resistant to antibiotics and because of this the anticipated therapeutic effect is never reached.In-hospital infections are often aggravated and large amounts of money are spent for treating complications in the patients'condition.In this paper a nonlinear optimal(H-infinity)control method is developed for the dynamic model of bacterial infections exhibiting resistance to antibiotics.First,differential flatness properties are proven for the associated state-space model.Next,the state-space description undergoes approximate linearization with the use of first-order Taylor series expansion and through the computation of the associated Jacobian matrices.The linearization process takes place at each sampling instance around a time-varying operating point which is defined by the present value of the system's state vector and by the last sampled value of the control inputs vector.For the approximately linearized model of the system a stabilizing H-infinity feedback controller is designed.To compute the controller's gains an algebraic Riccati equation has to be repetitively solved at each time-step of the control algorithm.The global stability properties of the control scheme are proven through Lyapunov analysis.The proposed method achieves stabilization and remedy for the bacterial infection under moderate use of antibiotics.展开更多
The control problem for the multivariable and nonlinear dynamics of unmanned aerial vehicles and micro-satellites is solved with the use of a flatness-based control approach which is implemented in successive loops.Th...The control problem for the multivariable and nonlinear dynamics of unmanned aerial vehicles and micro-satellites is solved with the use of a flatness-based control approach which is implemented in successive loops.The state-space model of(i)unmanned aerial vehicles and(ii)micro-satellites is separated into two subsystems,which are connected between them in cascading loops.Each one of these subsystems can be viewed independently as a differentially flat system and control about it can be performed with inversion of its dynamics as in the case of input–output linearized flat systems.The state variables of the second subsystem become virtual control inputs for the first subsystem.In turn,exogenous control inputs are applied to the first subsystem.The whole control method is implemented in two successive loops and its global stability properties are also proven through Lyapunov stability analysis.The validity of the control method is confirmed in two case studies:(a)control and trajectories tracking for the autonomous octocopter,(ii)control of the attitude dynamics of micro-satellites.展开更多
文摘The paper proposes a nonlinear optimal control approach for the model of the vertical take off and landing(VTOL)aircraft.This aerial drone receives as control input a directed thrust,as well as forces acting on its wing tips.The latter forces are not perpendicular to the body axis of the drone but are tilted by a small angle.The dynamic model of the VTOL undergoes ap-proximate linearization with the use of Taylor series expansion around a temporary operating point which is recomputed at each iteration of the control method.For the approximately linearized model,an H-infinity feedback controller is designed.The linearization procedure relies on the computation of the Jacobian matrices of the state-space model of the VTOL aircraft.The proposed control method stands for the solution of the optimal control problem for the nonlinear and multivariable dynamics of the aerial drone,under model uncertainties and external per-turbations.For the computation of the contollr's feedback gains,an algebraic Riccati equation is solved at each time-step of the control method.The new nonlinear optimal control approach achieves fast and accurate tracking for all state variables of the VTOL aircnaft,under moderate variations of the control inputs.The stability properties of the control scheme are proven through Lyapunov analysis.
文摘Attitude control and stabilization of micro-satellites is a nontrivial problem due to the highly nonlinear and multivariable structure of the satellites'state-space model.In this paper,a novel nonlinear optimal(H-infinity)control approach is developed for this control problem.The dynamic model of the satellite's attitude dynamics undergoesfirst approximate linearization around a temporary operating point which is updated at each iteration of the control algorithm.The linearization process relies on first-order Taylor series expansion and on the computation of the Jacobian matrices of the state-space model of the satellite's attitude dynamics.For the approximately linearized description of the satellite's attitude a stabilizing H-infinity feedback controller is designed.To compute the controller's feedback gains,an algebraic Riccati equation is solved at each time-step of the control method.The stability properties of the control scheme are proven through Lyapunov analysis.It is also demonstrated that the control method retains the advantages of linear optimal control that is fast and accurate tracking of the reference setpoints under moderate variations of the control inputs.
文摘A non-linear optimal(H-infinity)control approach is proposed for the dynamic model of multi-degree-of-freedom(DOF)electro-hydraulic robotic manipulators.Control of electro-hydraulic manipulators is a non-trivial problem because of their non-linear and multi-variable dynamics.In this study,the considered robotic system consists of a multi-link robotic manipulator that receives actuation from rotary electro-hydraulic drives.The article's approach relies first on approximate linearisation of the state-space model of the electro-hydraulic manipulator,according to first-order Taylor series expansion and the computation of the related Jacobian matrices.For the approximately linearised model of the manipulator,a stabilising H-infinity feedback controller is designed.To compute the controller's gains,an algebraic Riccati equation is solved at each time-step of the control algorithm.The global stability properties of the control scheme are proven through Lyapunov analysis.The proposed control method retains the advantages of typical optimal control,i.e.fast and accurate tracking of the reference setpoints under moderate variations of the control inputs.
基金supported by the Unit of Industrial AutomationIndustrial Systems Institute under Grant No.Ref.301022,Greece and RSP2024R150 of King Saud University,Riyadh,Saudi Arabia。
文摘The overuse and misuse of antibiotics has become a major problem for public health.People become resistant to antibiotics and because of this the anticipated therapeutic effect is never reached.In-hospital infections are often aggravated and large amounts of money are spent for treating complications in the patients'condition.In this paper a nonlinear optimal(H-infinity)control method is developed for the dynamic model of bacterial infections exhibiting resistance to antibiotics.First,differential flatness properties are proven for the associated state-space model.Next,the state-space description undergoes approximate linearization with the use of first-order Taylor series expansion and through the computation of the associated Jacobian matrices.The linearization process takes place at each sampling instance around a time-varying operating point which is defined by the present value of the system's state vector and by the last sampled value of the control inputs vector.For the approximately linearized model of the system a stabilizing H-infinity feedback controller is designed.To compute the controller's gains an algebraic Riccati equation has to be repetitively solved at each time-step of the control algorithm.The global stability properties of the control scheme are proven through Lyapunov analysis.The proposed method achieves stabilization and remedy for the bacterial infection under moderate use of antibiotics.
文摘The control problem for the multivariable and nonlinear dynamics of unmanned aerial vehicles and micro-satellites is solved with the use of a flatness-based control approach which is implemented in successive loops.The state-space model of(i)unmanned aerial vehicles and(ii)micro-satellites is separated into two subsystems,which are connected between them in cascading loops.Each one of these subsystems can be viewed independently as a differentially flat system and control about it can be performed with inversion of its dynamics as in the case of input–output linearized flat systems.The state variables of the second subsystem become virtual control inputs for the first subsystem.In turn,exogenous control inputs are applied to the first subsystem.The whole control method is implemented in two successive loops and its global stability properties are also proven through Lyapunov stability analysis.The validity of the control method is confirmed in two case studies:(a)control and trajectories tracking for the autonomous octocopter,(ii)control of the attitude dynamics of micro-satellites.
