Synthesis of Control System for Quad-Rotor Helicopter by the Network Operator Method

The work is devoted to application of the network operator method for solving the control system synthesis problem. The general synthesis problem statement is formulated with regard to its numerical solution. Complexity of the numerical solution of the general problem of control synthesis includes the necessity to find a multidimensional control function so that the control object from any initial state of some area falls into a terminal state with the optimal value of the quality criterion. The work uses the network operator method to solve the control synthesis problem. The method allows to find a solution in the form of an encoded mathematical expression with the help of special genetic algorithm. An example of quad-copter stabilization system synthesis by the network operator method is considered.

An identification control is a control of an object which mathematical model is unknown. For such objects initially the problem of identification is solved, and then for the resulting object model the problem of control synthesis is solved. As a result of control synthesis we obtain a multi-dimensional function that describes the dependence of control on the object state. After the implementation of this function in the control unit of the real object, it achieves the goal of control with optimal value of the quality criteria. To solve the identification and synthesis problems we use the method of network operator, which with the help of evolutionary algorithms finds the structure and parameters of the functions describing the model and functional dependence of control from the object state. In this paper, an example of using a network operator to solve the problem of identification control synthesis for a multilink robot is given.

This paper proposes a nonlinear control system for a quad rotor helicopter that aims to conduct wall inspection. Because wind reaction from a wall is significant when a helicopter approaches to the wall for its inspection, a robust controller is required. Firstly, the dynamics are derived by the Newton-Euler approach. A reference model with a cascaded control loop system including an inner loop for linearization and an outer loop for stabilization is designed. The inner loop uses feedback linearization. The outer loop uses state feedback control and a prefilter for stabilizing the linearized and decoupled multiple input and multiple output (MIMO) system. Unknown wind disturbances are considered and compensated by using a combined state and disturbance observer. The reference model generates a reference input for an embedded controller of a real plant. This proposed control system directly integrates measured distance into a feedback loop. Simulation results show the effectiveness of the nonlinear controller and observer.

An Underwater Quadrotor Control with Wave-disturbance Compensation by a UKF

As R/C airplane, Quad Rotor Helicopter (QRH)is tiltedits attitude to generate horizontal force component for moving direction. So attitude control is important. In the case of autonomous control, attitude control system tilts the airframe against to the disturbance such as wind. As a result, the attitude of flying QRH always slants. In this study, extra thruster rotors are mountedto keep the position and horizontal attitude of QRH. Extra thrusters are tilted to generate thrust against to the disturbance without airframe inclination. This system is constructed with two ducted fans which can slant by two axes. To oppose the crosswind, the thruster slants the ducted fan to leeward. Because the airframe is kept the horizontal, it is suitable for a precise measurement.

In recent years, electric helicopters are applied for many tasks due to their characteristics, and contact tasks with objects are also is expected. Although accurate angular velocity control of a rotor is required for contact force control, conventional angular velocity control systems have low robustness. A contact force control system using a quadrotor helicopter which includes rotor angular acceleration control systems in an inner loop is proposed. The system achieves accurate contact tasks in 3-dimensional space. The validity of proposed control system is verified by simulation.

In robot navigation experiment, a localization and motion control system is required to secure the agricultural robot motion in the environment. However, the high cost of localization system and complex structure of motion controller has limited the low cost agricultural mobile robot development. In this paper, a low-cost localization system and simple motion control system is presented. The localization system has been implemented using a dead reckoning method by accessing an incremental encoder’s reading. A simple cascaded motion control system based on proportional feedback kinematics controller and PI based controller was used to control the mobile robot motion. The performances of different turning methods: U turn and a π turn, were compared for lane changing, based on completion time, controller’s error and distance travelled. Simulation test of robot motion was conducted using a Simulink3d animation in MATLAB software. An experimental test in a real greenhouse environment was conducted to verify the simulation performance in motion control and localization system. The experimental and simulation results have shown that a U turn has the best turning performance with 69.1 % better efficiency in experimental mode and it is recommended to be applied in agricultural field.

Two approaches to control system design for constrained systems are studied. The first involves theoretical investigations of constrained model predictive control algorithms. The second involves extensions of robust linear control theory to handle the nonlinear control schemes commonly used in practice for constrained systems. A novel model predictive control algorithm, with attractive functional and numerical characteristics is developed. This algorithm minimizes peak excursions in the controlled outputs and is particularly suited to regulatory control problems common in continuous process systems. Model predictive control concepts are extended to uncertain linear systems. An on-line optimizing control scheme (RMPC) is developed which has as its objective the minimization of worst-case tracking error for an entire family of linear plants. For model uncertainty descriptions which provide plant impulse response coefficients as affine functions of uncertain parameters, it is shown that the required minimax optimization problem can be recast as a single linear program. The discrete time optimal averaging level control problem is formulated and solved. A finite horizon approximation to the problem is introduced and analytical solutions are obtained in important special cases. A model predictive control formulation is introduced which provides optimal flow filtering and integral action. Analysis tools are provided to characterize the trade-off between flow filtering and rapid integral action. A complete theory is developed for the multivariable anti-windup, bumpless transfer (AWBT) problem. The theoretical framework allows the consideration of any linear time invariant (LTI) control system subject to plant input limitations and substitutions. A general AWBT compensation scheme, applicable to multivariable controllers of arbitrary structure and order, is developed. Conditions are derived under which this general AWBT method reduces to any one of several well-known heuristics for AWBT (e.g., PI anti-reset windup and IMC). The design issues which affect AWBT performance are identified and quantitative analysis methods are developed. Sufficient conditions for nonlinear stability of the AWBT compensated system are provided. These results are a generalization of, and are less conservative than, those available in the AWBT literature. The definition of AWBT performance objectives which are independent of controller structure allows the formulation of a general AWBT synthesis problem. This formal synthesiproblem addresses each of the identified performance objectives in a quantitative manner. The synthesis problem is shown to be a special case of a constrained structure controller synthesis (CSCS) problem. A solution method via reduction to static output feedback is presented and the engineering trade-offs available in the AWBT design are discussed.

Least square based sliding mode control for a quad-rotor helicopter and energy saving by chattering reduction

Generally Quad-rotor type Unmanned Aerial Vehicles are unstable in nature, so to stabilize it, attitude controller is used. This paper presents a Fuzzy Logic based PID control system (FPID) for attitude stabilization of Quad-rotor Unmanned Aerial Vehicle (UAV). The Fuzzy logic controller updates the PID controller gains efficiently in such a way that it efficiently stabilizes the attitude of quad-rotor UAV. This method enhances the capabilities of conventional PID Controller to a dynamic PID Controller. The propose FPID control technique for attitude controlling of Quad-rotor UAV was tested on developed prototype of Quad rotor UAV for experimental purpose. Experimental results proved that proposed Fuzzy Logic based PID (FPID) controller quickly stabilized Quad-rotor UAV and its response time and settling time is reasonably good in attitude stabilization control application.

This article is devoted to the problem of the optimal synthesis on a subspace for the 2 and 3-dimensional case for the linear control system $\dot{x_1} = u, \dot{x}_i=x_{i-1}, i=\overline{2,n}$ with $|u|\le1$. This problem is related to the problem of optimal synthesis into the point, which solution was presented by V. I. Korobov and G. M. Sklyar and is based on the moment min-problem, but its difference with respect to the original problem is that the number of unknown functions is greater than the number of variables, which requires using the methods for the parametric optimization. As in the problem of optimal synthesis into the point, we search for the optimal solution in the form of piecewise function with $u=\pm 1$ and $n-1$ switching points, which is optimal according to Pontryagyn's maximum principle and the theorem on $n$ intervals. In this article we consider approaches and problems related to the finding of the general solution of the optimization problem and solve the cases of $n=2$ and $n=3$. The interest of the obtain results is the fact that unlike the solution for the single endpoint $x_T$ the general solution for the subspace may have less than $n-1$ switching points, or not have switching points at all, depending on the parameters of the subspace. In our work, we give the solution for the problem of synthesis of the two-dimensional system onto a subspace $G: {x_2 = k x_1}$ for all values of $k$ using the moment min-problem and the optimization methods. For the three-dimensional system we consider the problem of synthesis on a plane $x_3 = k_1 x_1 + k_2 x_2$ and obtain the number of the switching points depending on the values of $k_1$ and $k_2$, construct trajectories and present the equations the for optimal time $\Theta$ for different cases.

In this paper, a self-repairing control scheme for attitude control of a quadrotor helicopter via active disturbance rejection control is proposed. Firstly, a model of the quadrotor helicopter is gained by its dynamic equations with pitch, roll and yaw axis. Then the active disturbance rejection controller is introduced, which is used to design the control system. The control system consists of PID controller in inner-loop and ADRC controller in outer-loop. Disturbances and uncertainties can be compensated by the ADRC to achieve smaller tracking error. Finally, the simulation results of the four-rotor helicopter validate the efficiency and self-repairing capability of the proposed control algorithm, compared with that of the PID control and the separate ADRC control.

Purpose The paper presents the results of work on control systems of bearingless electric motors. Authors proposed the applications of bearingless electric machines for aircraft actuation system. Suggested solution characterizes novel concept of on-board equipment design such as More Electric Aircraft. Magnetic suspension technology allows elimination of friction force and the negative performance features of classic bearing system. However, to achieve all these purposes appropriately, dedicated control system must be also applied. Design/methodology/approach The development of a control system of bearingless electric machine is presented in detail. Mathematical model and construction of induction bearingless motor are widely discussed. Then, proportional–integral-derivative controller algorithm designing for BEM control system was presented using the well pole placement method. Simulation model of BEM control system with use of Matlab-Simulink software was shown. Finally, experimental studies on laboratory stand were introduced. The paper presents design methodology of conventional and advanced control system of bearingless motor. Findings The presented concept of the bearingless electric machines could be applied in the on-board actuation system. During research, full control system of bearingless electric motor was designed and tested. This system consisted of two subsystems. The first responded for rotary speed stabilization and second one was designed for position control of the rotor in the air gap. Practical implications The presented concept of the bearingless electric machines could be applied in the on-board actuation system. During research, full control system of bearingless electric motor was designed and tested. This system consisted of two subsystems. The first responded for rotary speed stabilization and second one was designed for position control of the rotor in the air gap. Originality/value The idea of active magnetic suspension system will be implemented for aviation on technology readiness level V. The paper presents unique laboratory stand with bearingless electric motor and experimental studies. The stable time responses of designed control system were presented and discussed. In addition, preliminary considerations of advanced control system with robust controller were introduced as well.

Design and Flight Testing of a Model Following Control System for Helicopters

The jerk (the time rate of change of acceleration) is one of the most important kinds of bodily sensitive information. In driving situation, when a vehicle accelerates or decelerates rapidly, skilled drivers can adaptively control the vehicle by perceiving wheel spin or wheel lock from subtle vehicle jerk information, rather than from wheel-speed information. This suggests that the performance of vehicle motion control systems, including the extent of "natural" feeling for drivers, can be improved by enabling the systems to detect jerk and/or acceleration information, and emulate responses of a skilled driver. We have developed a sensor for deriving the values of both acceleration and jerk by using the law of electromagnetic induction. This sensor performs well and has several potential applications. This paper introduces the principle and performance of jerk sensor, and also proposes other possibility of motion control systems using jerk information.