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Non-inverting Buck Boost converters (NIBB) have been utilized as interfacing converters for energy storage, due to the high steady-state efficiency offered by the asynchronous control. However, classical asynchronous control has inherent poor dynamic performance when the input and output voltages are near. To solve the problem, concept of “dynamic mode switching” is first proposed in this paper. Instead...
The paper treats a class of human walking robots, the athlete robot (AR). The dynamic equations of this model are generated by Euler Lagrange method as a multi-input-multi-output under-actuated model. The balancing control on one leg in the stance phase is studied. The hierarchical sliding mode control algorithm is proposed. Numerical simulations show the method efficiency.
Model Predictive Control (MPC) is a candidate solution to aggressively control a constrained plant. In Tube Model Predictive Control (TMPC), optimality is traded for robustness which is a key aspect in flight controls where the plant is subject to many disturbances and uncertainties especially related to aerodynamics and wind. Yet MPC comes with large computational effort and thus reduced execution...
This paper illustrates the importance of control on energy saving opportunity for electrical drives systems. The paper's objective is to present the results for a real time implementation of optimal control law for an electrical drive system with induction machine at variable flux. The optimal control is based on numerical integration of the Matrix Riccati Differential Equation and the optimal control...
Shared control techniques have a great potential to create synergies in human-machine interaction for efficient and safe applications. However, an optimal interaction requires the machine to consider the individual behavior of the human partner. A widespread approach for modeling human behavior is given by optimal control theory, where the movement trajectories of a human arise from an optimized cost...
In this paper, the time-consistent solution of a time-inconsistent stochastic LQ problem is investigated. Necessary and sufficient condition is obtained to the existence of the open-loop time-consistent equilibrium control, which contain the solvability of certain forward-backward stochastic difference equation systems, the stationary conditions and the convexity conditions.
The extended weighted and objective functions are proposed based on the time-to-go function. According to the optimal control theory, a family of extended optimal trajectory shaping guidance laws is deduced for the constant maneuvering target. The variation of miss distance of position and angle with flight time is analyzed without considering dynamic lag. With the introduction of target hovering...
In this paper, we study optimal control problems for linear continuous-time hybrid systems. We adopt an approach to prepare some candidates of mode distributions and minimize value functions at each time for the systems and performance indices to optimize system states and mode distributions simultaneously. We state a class of principles of hybrid optimality, which gives a theoretical base of the...
To reduce the effects of modeling imprécisions, in the traditional “Receding Horizon Control” that works with finite horizon lengths, in the consecutive horizon-length cycles, the actually measured state variable is used as the starting point in the next cycle. In this design, within a horizon-length cycle, a cost function is minimized under a constraint that mathematically represents the dynamic...
This work provides a comparative review of three different numerical methods generally used to discretize continuous-time non-linear equations appearing in model predictive control problems: direct multiple shooting, direct collocation and successive linearizations. An overview of the characteristics of each method is given and the performance of each method is evaluated through the simulation of...
This paper presents a stochastic optimal control approach suitable for implementation on small unmanned aerial vehicles (UAV). The controller provides tracking of a target at a desired distance, keeps the target away from the sector of blind spots and prevents flying over the target to avoid the flipping images in the camera's recorded sequence. The controller is based on a two-dimensional stochastic...
The optimal control strategy for a wave energy converter (WEC) with constraints on the control torque is investigated. The goal is to optimize the total energy delivered to the electricity grid. Using Pontryagin's maximum principle, the solution is found to be singular-bang. Using higher order conditions, the optimal control on the singular arc is found as a function of the state and costate trajectories...
The paper concerns the problem of the numerical simulation of hybrid systems with sliding modes. We give an overview of the numerical simulation procedures which have been described in the literature and next we present our proposition of the simulation code. What differs our solution from others is the utilization of differential-algebraic equations (DAEs) during the simulation of a sliding motion...
This paper presents a method for extending the generalized polynomial chaos method with stochastic collocation, so that expansion coefficients for further continuous distributions other than the standard distributions of the generalized polynomial chaos can be calculated. This is achieved by using a Gaussian mixture model to approximate the desired arbitrary continuous input distribution. This incorporation...
This paper presents a novel approach for timeoptimal model predictive control. In contrast to a global uniform time scaling, the underlying optimal control problem rests upon a dynamic, local temporal discretization of the shooting grid. The approach seeks for a grid partition with minimum overall transition time. Furthermore, a multi-stage optimization iteratively adapts the number of grid points...
Optimal control has been a very attractive and desirable feature for many dynamic and static systems, An effective online technique for finite-horizon nonlinear control problem is offered in this paper. The idea of the proposed technique is to combine the differential State Dependent Riccati equation filter algorithm and the finite-horizon SDRE technique. Genetic algorithm is used to calculate the...
This paper proposes an optimal tracking control of completely unknown affine nonlinear systems using a system augmentation scheme and a modified discounted performance function, where the feedforward and feedback control actions can be obtained simultaneously. We first present an adaptive identifier to estimate the unknown dynamics, where the estimated parameters are updated based on a new adaptive...
Object of this work is hypersonic cruise vehicle which cruises at Mach number beyond 5 in atmosphere. Range of this vehicle is often restricted by the poor aerodynamic, propulsive and structural performances and severe persistent aerodynamic heating. To extend its range, optimal periodic cruise trajectory has been adopted herein to improve fuel efficiency and remit heat accumulation. The performance...
This paper is concerned with an optimal control problem of anticipated forward-backward stochastic differential equation with delay. We obtain an explicit representation of optimal control for delayed problem first, and then use it to solve a delayed cash management problem with recursive utility. The explicit optimal control strategy of the investor is given and some numerical simulations are used...
An optimal impact angle control guidance law is proposed in this paper. The missile system is approximated under the small heading error assumption and the impact angle control guidance law is derived based on the approximated system to minimize the energy cost. The proposed guidance law has a form of biased PNG law and it's in accord with the previous result of PNG in the form acceleration command...
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