Planar Vertical Take-off And Landing Research Articles

Control of the PVTOL with Strong Input Coupling

This paper studies the modeling and control of a Planar Vertical Take-Off and Landing (PVTOL) with steerable thruster. A longitudinal model is obtained using Newton’s second law for the PVTOL which evolves in 3 degrees of freedom and has two control inputs. The aerial vehicle is driven by steerable propulsion controlling its evolution in the vertical plane through the thrust and torque control inputs, which drive the vehicle body and generate a rotation. The obtained model is nonlinear and is significantly different with respect to the well-known PVTOL. For this reason, different control algorithms are presented, and the closed-loop behavior is studied for each of them. The proposed control strategies perform a stationary flight at a desired altitude and control the position of the aerial vehicle. The performance of the proposed control algorithms is tested in numerical simulations.

Improved PVTOL Test Bench for the Study of Over-Actuated Tilt-Rotor Propulsion Systems

In recent years, applications exploiting the advantages of tilt-rotors and other vectored thrust propulsion systems have become widespread, particularly in many novel Vertical Takeoff and Landing (VTOL) configurations. These propulsion systems can provide additional control authority, enabling more complex flight modes, but the resulting control systems can be challenging to design due to the mismatch between the vehicle degrees of freedom and physical input variables. These propulsion systems present both advantages and difficulties because they can exert the same overall forces and moments in many different propulsive configurations. This leads to the traditional non-uniqueness problem when using the inverse dynamics control allocation approach, which is the basis of many popular VTOL control algorithms. In this article, a modified Planar VTOL (PVTOL) test bench configuration, which considers an arbitrary number of co-linear tilting rotors, is introduced as a benchmark for the study of the control allocation problem. The resulting propulsion system is then modeled and linearized in a closed and compact form. This allows a simple and systematic derivation of many of the currently used control allocation approaches. According to the proposed PVTOL configuration, a two-rotor test bench is implemented experimentally and a decoupling control allocation strategy based on Singular Value Decomposition (SVD) analysis is developed. The proposed approach is compared with a traditional input mixer algorithm based on physical intuition. The results show that the SVD-based solution achieves better cross-coupling reduction and preserves the main properties of the physically derived approach. Finally, it is shown that the proposed PVTOL configuration is effective for studying the control allocation problem experimentally in a controlled environment and could serve as a benchmark for comparing different approaches.

Lyapunov Stability of a Planar Vertical Take-Off and Landing Aircraft Exerting a Force in the Environment

This work proposes a simplified control method to stabilize the model of a nonlinear Planar Vertical Take-Off and Landing (PVTOL) system when a constant force is applied in the horizontal axis. Since the stability analysis is based on a Lyapunov function, exponential stability is guaranteed when the initial conditions fall inside a domain of attraction that is also specified. The performance of the suggested control algorithm is demonstrated using numerical simulations.

A simple nonlinear stabilization control of planar vertical take‐off and landing aircraft based on finite‐time control and Controlled Lagrangians

AbstractA simple nonlinear stabilization controller for the planar vertical take‐off and landing (PVTOL) aircraft is proposed by employing finite‐time control method and Controlled Lagrangians method in this paper. Compared with other results, the new form of the proposed controller is simpler, the parameters selection of the proposed controller is more flexible and the stability analysis of the closed system is easier. The control strategy consists of two controllers. The first controller is designed based on finite‐time control method to make the states of the fully actuated system converge to zero within a finite time. After that, the system can be simplified to a 2‐DOF underactuated system. And the second controller is designed based on Controlled Lagrangians method to make the states of the underactuated system asymptotically stable. The simulation results verify the effectiveness and superiority of the proposed controller.

PVTOL global stabilisation using a nested saturation control

This paper presents how the nested saturation control introduced in Teel (1992) can be modified to stabilise the model of the Planar Vertical Take-Off and Landing (PVTOL) system. A particular choice of the amplitudes of the nested saturations controller is given such that global stability of the closed loop system is obtained. The proof is given in detail. Numerical simulations illustrate the performance of the proposed control algorithm.

Robust constrained trajectory tracking control for a PVTOL aircraft subject to external disturbances

This paper addresses the trajectory tracking control problem of a planar vertical take-off and landing (PVTOL) aircraft in the presence of position constraints and external disturbances. A novel robust constrained control approach is proposed by incorporating the barrier Lyapunov function (BLF) and nonlinear damping items within the framework of dynamic surface control design. The dynamic surface control is used to avoid the ‘explosion of terms’ problem of the traditional backstepping control. The tan-type BLF is utilised to preserve the position tracking errors always within the predefined position constraints. The nonlinear damping items are applied to handle the effect of external disturbances. The uniform ultimate boundedness of the resulting closed-loop system is rigorously proved through the Lyapunov’s direct method. A distinct feature of the proposed control approach is that it is a general methodology for the trajectory tracking control of PVTOL aircraft with or without position constraints. Both theoretical analysis and numerical simulations illustrate the effectiveness and benefits of the proposed control approach.

Design and tuning of pid algorithm for optimum performance of pvtol system

In this paper different design scheme for a PID controller have been introduced for a single axis of a quadcopter. This type of model is also known as PVTOL (planar vertical take-off and landing) system. The PVTOL system possess complicated roll control schemes, non-linearity, low stability and is a second order type process. This paper aims to present a comparison between different controllers used in a dynamic model of a PVTOL platform. Performance comparison of classical Zeigler Nicholas (ZN-PID) is done against Genetic Algorithm (GA) based controller optimization. The results are obtained using MATLAB and SIMULINK, the (ZN-PID) and (GA) based controller is designed for disturbance rejection, close loop response and set point tracking.

Two PVTOLs cooperative slung‐load transport control based on passivity

AbstractThis work addresses the problem of two unmanned aerial vehicles (UAVs) transporting a slung‐load on a plane. The vehicles presented are a simplified version of the classical planar vertical take‐off and landing (PVTOL). The proposed solution implements a decentralized control scheme based on the concept of passivity where there is no explicit communication between agents. This is accomplished by taking advantage of the physical connection between the agents and the load. In contrast with similar control algorithms based on force control, like impedance filters, the objective is to drive the system into a state of minimal energy. In addition to this, the presented control strategy differs from other passivity based methods, like an interconnection and damping assignment passivity‐based control, in that the method can also be used to accommodate more complex control strategies that do not necessarily depend on the energy of the system.

A Simple Approach to Regulate a PVTOL System Using Matching Conditions

In this work, based on shaping an energy function, it is introduced an output-feedback regulation control law for a Planar Vertical Takeoff and Landing (PVTOL) aircraft. To this end, a version of the matching control energy method is used to construct the Lyapunov candidate function and the stabilizer controller to regulate the PVTOL aircraft. The non-measurable system velocities are recovered using a suitable exact differentiator observer, achieved through super-twisting based observer. The theorem of LaSalle, together with some tools from the cascade system theory, was used to carry out the closed-loop stability analysis. Using a suitable finite time-varying identificator, the obtained controllers were improved to compensate bounded, smooth, and matching perturbations. Numerical simulations were included to test the effectiveness of the obtained controller.

Research on reconfigurable control for a hovering PVTOL aircraft

This paper presents a novel reconfigurable control method for the planar vertical take-off and landing (PVTOL) aircraft when actuator faults occur. According to the position subsystem within the multivariable coupling, and the series between subsystems of position and attitude, an active disturbance rejection controller (ADRC) is used to counteract the adverse effects when actuator faults occur. The controller is cascade and ensures the input value of the controlled system can be tracked accurately. The coordinate transformation method is used for model decoupling due to the severe coupling. In addition, the Taylor differentiator is designed to improve the control precision based on the detailed research for tracking differentiator. The stability and safety of the aircraft is much improved in the event of actuator faults. Finally, the simulation results are given to show the effectiveness and performance of the developed method.

Research on reconfigurable control for a hovering PVTOL aircraft

This paper presents a novel reconfigurable control method for the planar vertical take-off and landing (PVTOL) aircraft when actuator faults occur. According to the position subsystem within the multivariable coupling, and the series between subsystems of position and attitude, an active disturbance rejection controller (ADRC) is used to counteract the adverse effects when actuator faults occur. The controller is cascade and ensures the input value of the controlled system can be tracked accurately. The coordinate transformation method is used for model decoupling due to the severe coupling. In addition, the Taylor differentiator is designed to improve the control precision based on the detailed research for tracking differentiator. The stability and safety of the aircraft is much improved in the event of actuator faults. Finally, the simulation results are given to show the effectiveness and performance of the developed method.

Priority altitude PVTOL aircraft control via immersion and invariance

ABSTRACT In this work, the immersion and invariance (I&I) control technique is used in order to design a new controller that stabilises the PVTOL (planar vertical take-off and landing) aircraft system. The controller gives priority to the control of the aircraft's altitude before controlling the lateral displacement, fact from which interesting features as less thrust effort and less aggressive manoeuvres for roll moment are gained. The fundamental idea for the development of the proposed controller is based on the selection of the target dynamic system in accordance with the nature of the translational motion system to then stabilise the off-manifold dynamics by using the rotational motion system. It is proved that the proposed control scheme is globally asymptotically stable. Simulation results validate our proposal.

Robust Trajectory‐Tracking Control of a PVTOL under Crosswind

AbstractThis work proposes a robust controller to solve the trajectory‐tracking control problem of planar vertical take‐off and landing (PVTOL) aircraft under crosswind. The controller combines input–output feedback linearization and active disturbance rejection control techniques. The former linearizes the PVTOL dynamics and the latter actively estimates and compensates for the crosswind effects. Numerical simulations assess the effectiveness of the proposed approach.

Development of Experimental Platform for Control System of a Planar Vertical Take-off and Landing Unmanned Aerial Vehicle

The main contribution of this paper is to present the design and construction of an experimental platform applied to a Planar Vertical Take-off and Landing (PVTOL) Unmanned Aerial Vehicle (UAV) prototype by considering the rotational and translational motion of the vehicle. The instrumentation of the experimental platform and their parts are presented in order to explain how the system measures the position and the rotational displacement of the vehicle. Finally, experimental results are presented using a hierarchical scheme considering the well-known time-scale separation between the rotational and the translational motion of the PVTOL employing the experimental platform. The effectiveness and performance of the proposed experimental platform show that the platform can be used to apply different control strategies.

Cascade ADRC-based fault-tolerant control for a PVTOL aircraft with potential actuator failures

This paper presents a novel reconfigurable control method for the planar vertical take-off and landing (PVTOL) aircraft with potential actuator failures. A cascade active disturbance rejection controller (ADRC) is used to counteract the adverse effects when the actuator failure occurs. The coordinate transformation is used for model decoupling due to the severe coupling between some variables. This approach does not require the accurate mathematical model of the controlled system and ensures that the reference input value can be tracked rapidly and accurately. The stability and safety of the aircraft is much improved in the event of actuator failures. Finally, the simulation results are given to show the effectiveness and performance of the developed method.

Robust Stabilization of Nonlinear PVTOL Aircraft with Parameter Uncertainties

AbstractIn this work, the stabilization control problem is investigated for the planar vertical take‐off and landing (PVTOL) aircraft with unknown model parameters. To cope with the challenges caused by non‐minimum phase and parametric uncertainties, a new appropriate output, different from the general centroid position output, is carefully constructed to ensure the zero dynamics asymptotically stable, then the sliding‐mode technique is applied to design a state feedback control law. The proposed robust control law is proved able to asymptotically stabilize the PVTOL aircraft to the desired fixed position with null velocities and roll angle despite the unknown model parameters. Simulation examples illustrate the effectiveness of the proposed control algorithm.

Robust Model Predictive Control of PVTOL Aircraft∗∗This work was supported by Center of Excellence in Complex and Nonlinear Dynamical Systems (CoE-CNDS), established under TEQIP-II, Subcomponent 1.2.1.

Abstract The paper presents a Tube Based Model Predictive Control (TB-MPC) strategy for robust stabilization of Planar Vertical Take-off and Landing (PVTOL) aircraft. PVTOL system is considered as a benchmark for investigating dynamics and control related issues for unmanned aerial vehicles (UAVs). Control problem of such a system is challenging due to its nonlinear dynamics and under actuated nature. Moreover, a major problem with these systems is the loss of controllability at certain points in the state space. To overcome these issues a unique approach has been used to approximate the nonlinear dynamics of the PVTOL system under additive disturbance with a set of linear systems to form polytopic linear differential inclusion (PLDI). Obtained approximation always satisfies the controllability condition. The proof of stability and feasibility for MPC has been derived. The effectiveness of the proposed control strategy is shown via simulations by stabilizing the aircraft, while rejecting the effects of disturbances.

An Actuator Fault Detection and Isolation method design for Planar Vertical Take-off and Landing Unmanned Aerial Vehicle modelled as a qLPV system

This paper presents the design of a tracking controller and a fault detection and isolation system for a Planar Vertical Take-off and Landing (PVTOL) Unmanned Aerial Vehicle (UAV) under actuator faults. In order to control the PVTOL, the dynamic system is divided into three subsystems driven by the rotational, the altitude, and the position dynamics. The altitude and position subsystems are based on qLPV model while the rotational subsystem is linear. A linear observer applied to the rotational subsystem is considered to detect actuator faults, which can occur as failures (loss of a propeller or a motor) or partial faults (degradation). Furthermore, fault isolation is done by measuring roll velocity due to the actuator fault. In all cases, sufficient conditions for the existence of the observer and the controllers are given in terms of linear matrix inequalities (LMIs). Finally, simulations (on the nonlinear model) are done in order to illustrate the effectiveness of the proposed methodology.

Adaptive control for the PVTOL system via Minimum Projection Method

“Dynamic extension” is commonly used for stabilization of planar vertical take off and landing (PVTOL) system. Most of controllers designed by this method are based on “dynamic” control Lyapunov functions(CLFs). We design a C8differentiable “static” strict CLF for the PVTOL system by dynamic extension and minimum projection method. Then we propose an adaptive control law with the an inverse optimal controller based on the static CLF.

Research on One Type of Saturated Nonlinear Stabilization Control Method of X-Z Inverted Pendulum

摘要: X-Z倒立摆不仅具有普通倒立摆的最小相位和欠驱动特性, 同时具有更多的控制自由度.通过一定的状态变换, 发现了X-Z倒立摆与平面垂直起降飞行器模型之间的等价关系. 基于该等价关系,借鉴平面垂直起降飞行器的控制方法, 把饱和非线性控制方法应用于X-Z倒立摆的稳定控制. 通过与PID (Proportion integration differentiation)控制方法的仿真对比,证明了该稳定控制方法的有效性. 关键词: X-Z倒立摆 / 平面垂直起降飞行器 / 稳定 / 非最小相位 / 欠驱动