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This paper deals with the robust control problem for linear systems with both gain and time constants variations under fractional order PIλDμ controller. A robustness specification to the parameters variations is proposed. For those systems with more than one uncertain time constant, the robustness specifications are analyzed and simplified. To minimize the phase offset nearby the crossover frequency,...
For a PWM inverter system, the output ac current is expected to be a sinusoidal waveform after filtering; however, PWM inverters have two drawbacks causing distortion of output waveform. One is the presence of harmonics, and the other is the variations of the system parameters. In this paper, a robust Doubly Coprime Factorization Disturbance Observer (robust DCFDOB) is applied to a dc-to-ac inverter...
Dexterous manipulation has broad applications in assembly lines, warehouses and agriculture. To perform broad-scale manipulation tasks, it is desired that a multi-fingered robotic hand can robustly manipulate objects without knowing the exact objects dynamics (i.e. mass and inertia) in advance. However, realizing robust manipulation is challenging due to the complex contact dynamics, the nonlinearities...
The design of a disturbance observer (DOB) for a nonlinear half-car hydraulic active suspension system is presented. The system is controlled by the flatness-based controller (FBC) which is capable to provide efficient control under deterministic road disturbances and model uncertainties. The main objective is to design the mutually coupled general-proportional-integral (GPI) disturbance observers...
In this paper, robust Integral Sliding Mode Control (ISMC) will be proposed for an underactuated rotary hook system in order to deal with parametric uncertainties presenting in the system parameters. By using the proposed ISMC, the reaching phase encountered in the conventional SMC will be eliminated and as a consequence, the dynamic ambiguity, which occurs when the system is in the transient state...
Despite many proposed solutions, multi-object tracking remains a challenging problem in complex situations involving partial occlusions and non-uniform and abrupt illumination changes. Considering modular systems, the tracking performance strongly depends on the consistency of the different blocks relatively to error features. In this work, using the Belief Function framework, we take into account...
The performance in any flight system depends on the feedback control scheme. Therefore, in a first stage, we apply as a basis the so-called Model Free Control (MFC) for the development of nonlinear flight control law that could be implemented without much difficulty. As second step, an in-depth discussion with respect to the control performance is highlighted. Due to the novel form that we propose,...
The recent paper [9] studied the cooperative robust output regulation of linear multi-agent systems with arbitrary parametric uncertainty via the distributed output feedback control, where the network is assumed to be fixed. In this paper, we further show that the same controller is also efficient for the more general uniformly connected switching network. In contrast to the traditional quadratic...
This paper investigates robust adaptive control of uncertain switched linear systems considering disturbances. Two modifications of the adaptive law of switched linear systems [1] based on parameter projection and a leakage approach are developed to guarantee the stability of the closed-loop switched linear system: a projection law that requires knowledge of the bounds of the parameter estimates;...
Digitalisation of industrial processes, also called the fourth industrial revolution, is leading to availability of large volume of data containing measurements of many process variables. This offers new opportunities to gain deeper insights on process variability and its effects on quality and performance. Manufacturing facilities already use data driven approaches to study process variability and...
Device to device(D2D) communication exploits the proximity between mobile devices to allow direct communication. Doing so offers advantages which include less energy consumption, hop gain, reduced load on the base station among others. For instances where the channel between the D2D devices does not allow for efficient direct communication, a suitably selected idle mobile device can act as a relay...
This paper studies a class of fuzzy-stochastic resource-allocation (fSRA) problems which involve both subjective and objective uncertainty (i.e., fuzziness and randomness). In the FSRA, the capability of a resource to complete a task is characterized by a probability parameter which is uncertain and stochastic while the reward of a task is expressed as a fuzzy number. The FSRA problem is formulated...
This paper investigates the robust weighted fusion estimation problem of multi-sensor systems with mixed uncertainties, including stochastic parameter uncertainties, missing measurements and uncertain noise variances. The stochastic parameter uncertainties are described by multiplicative noise. Especially, the variances of both the multiplicative and additive noises are uncertain. By introducing two...
A tractor-trailer wheeled robot (TTWR) is a kind of modular robotic system that consist of the tractor and the trailer are mechanically coupled to each other. It is impossible to obtain an exact dynamics model due to unknown parameters, or unpredictable and irregular features, external disturbance. Because of the non-holonomic constraints property, this paper proposes an adaptive robust cascade controller...
The attitude control for reusable launch vehicles (RLV) is responsible for the robust operation to avoid the major deterioration from uncertainties of parameters and external disturbances in the reentry phase. Targeting for these practical issues with the study of the feedback-linearized RLV rotational equations of motion, two global sliding mode control (SMC) strategies are proposed with modified...
In recent years, quadrotor unmanned aerial vehicles have played an important role in many aspects. Therefore, people put higher demands on the robustness of the quadrotor UAV's control. In this paper, a control algorithm based on signal compensation is proposed. Compared with the PID algorithm, this algorithm has better robustness to external disturbance and modeling uncertainty. Moreover, the controller...
This paper is concerned with the robust normalization and stochastic stabilizing problem for singular Markovian jump systems with norm-bounded parameter uncertainties and time delay. A novel proportional-derivative controller with memory is designed. Sufficient conditions are derived to ensure that the closed-loop system is not only robust normal, but also stochastically stable. In addition, the explicit...
In this paper, an attitude control strategy is proposed for a class of tail-sitter aerial vehicles, which is required to achieve the desired tracking control performance during the mode transition. The resulted controller is constructed by a nominal controller and a robust compensator to reduce the effects of nonlinear dynamics and uncertainties. Theoretical analysis and numerical simulation results...
The attitude tracking control problem of reusable launch vehicle (RLV) in reentry phase is investigated in this paper. The control-oriented model is firstly developed from the attitude model, and it is decomposed into two subsystems on the basis of the engineering backgrounds of RLV. Via backstepping design procedure, sliding mode control scheme is designed while the lumped uncertainty is estimated...
A disturbance estimation approach is presented for a class of nonlinear systems by incorporating two-layer structure. The multiple-disturbances concerned are supposed to include two parts. One is generated by an exogenous system, which can represent the single-sinusoidal signal with unknown frequency. The other part is norm bounded uncertain disturbance. The special auxiliary observer represent the...
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