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The purpose of this paper is to derive a robust nonlinear attitude control law intended for practical application.

The method of input/output feedback linearization is utilized for having a linear model and a recently developed almost disturbance decoupling (ADD) approach is adopted for designing a robust satellite attitude control (SAC) system. The kinematics of the satellite is modeled by modified Rodriguez parameters because of their continuous invertibility. The design is simulated on the model of a realistic satellite project (BILSAT‐I), which is developed by the Turkish Scientific and Technological Research Council.

The torque requirement of the operation does not exceed the maximum limit provided by the actuator. The square error levels are staying under the boundary of final global attractor, which is one of the important proofs for the successful operation of the generated ADD control law.

The ADD concept is investigated on SAC problem. By that way, simple control structures with known disturbance attenuation capability can be designed.

The purpose of this paper is to analyze the results of the Jacobian matrix linearization of the satellite attitude dynamics with modified Rodriguez parameters (MRP) as attitude representation.

The satellite dynamics is linearized using Jacobian differentiation around origin and reference values of the MRP. The controller is designed through linear quadratic regulation approach.

It is found that, for both cases the overall system converges but there exists a tracking error. The error can be reduced by increasing the controller coefficients in both cases however cannot be eliminated. In the case of linearization around zero, the torque requirements are quite higher than the case of linearization around the reference attitude trajectory.

The attempt of Jacobian linearization of a satellite dynamics with the MRP as the attitude representation constitutes the value of this paper. In addition, the results obtained in the derivations may be used in future research.

The purpose of this paper is to design and simulate a linearized attitude stabilizer based on linear quadratic regulator theory (LQR) using the multiplicative definition of the attitude.

The attitude is modeled by the modified Rodriguez parameters that provide a minimal representation of attitude and always invertible kinematics. The nonlinear model of the satellite attitude dynamics is linearized around the origin and an LQR is proposed for the linearized design. They are also simulated using the original nonlinear satellite dynamics in order to verify that the controller is operating properly. Simulations include randomly selected initial conditions to justify the stability against various initial conditions.

Theoretically, the resultant controllers are locally stable around the origin. However, the simulation results show that the attitude is well regulated in the presence of both inertia uncertainties and random initial conditions.

The originality of this work is due to its demonstration that complicated attitude regulators are not the solution for proper satellite or spacecraft attitude stabilization.

This paper aims to investigate the fast attitude coordinated control problem for rigid satellite swarms with communication delays.

Based on behavior‐based control approach, the attitude control system is designed to guarantee that the attitude of the satellite swarm converge to a dynamic reference state in finite time. A fast sliding mode is developed to improve the convergence rate and robustness of the control system. All the effects of communication delays, parameter uncertainties and external disturbances are taken into account simultaneously, and the communication topology of the satellite swarm can be arbitrary types. Numerical simulations are provided to demonstrate the analytic results.

Despite the existence of communication delays, parameter uncertainties and external disturbances, the stability of the closed‐loop system can be successfully guaranteed and the proposed control strategies are effective to overcome these unexpected phenomena subject to arbitrary communication topology.

This paper introduces a fast terminal sliding mode control method which can guarantee the fast convergence of the attitude state of the satellite swarm in the presence of communication delays, switched communication topology, parameter uncertainties and external disturbances.

The purpose of this paper is to present fault tolerant control of a quadrotor based on the enhanced proportional integral derivative (PID) structure in the presence of one or more actuator faults.

Mathematical model of the quadrotor is derived by parameter identification of the system for the simulation of the UAV dynamics and flight control in MATLAB/Simulink. An improved PID structure is used to provide the stability of the nonlinear quadcopter system both for attitude and path control of the system. The results of the healty system and the faulty system are given in simulations, together with motor dynamics.

In this study, actuator faults are considered to show that a robust controller design handles the loss of effectiveness in motors up to some extent. For the loss of control effectiveness of 20 per cent in first and third motors, psi state follows the reference with steady state error, and it does not go unstable. Motor 1 and Motor 3 respond to given motor fault quickly. When it comes to one actuator fault, steady state errors remain in some states, but the system does not become unstable.

In this paper, an enhanced PID controller is proposed to keep the quadrotor stable in case of actuator faults. Proposed method demonstrates the effectiveness of the control system against motor faults.

This paper aims to focus on the implementation of the integral back‐stepping control on the model of BILSAT – 1 satellite of the Turkish Scientific and Technological Research Council (TUBITAK).

The nonlinear model of the satellite is divided into three groups and the control Lyapunov function is constructed systematically. The formed closed loop system is analyzed for stability according to a recently developed stability analysis procedure and multi‐run simulations.

Since the studied model includes the dynamics of a practical reaction wheel (SSTL Type: Microwheel), the simulation results showed that the designed controllers are suitable for practical application. The torque requirement is far below the maximum torque supplied by the wheel. In addition, the system seems to be quite fast and robust against the parametric uncertainties.

Since the control system is nonlinear, the computational complexity will be an issue in practical application. The stability analysis should be improved to have more reliable information concerning the disturbance torques. Currently this analysis is performed by multi‐run simulations. An observer or estimator may also be designed in order to compute the attitudes from the gyroscope readings.

The controller designed here can be implemented on the proceeding satellite projects (foregoing BILSAT projects) by TUBITAK.

The paper provides a satellite control application of back‐stepping using a model involving modified Rodriguez parameters and reaction wheel dynamics that is not studied in the literature.

The literature on financing constraints in emerging markets is still under-researched and is often described as a “black box.” This study aims to shed light on this underexplored area for emerging economies. Specifically, it attempts to understand the phenomenon of financing constraints through a systematic review and bibliometric analysis.

A systematic literature review and bibliometric analysis are used to identify the main features of investment-cash flow sensitivity and the financing constraints hypothesis in the context of emerging markets.

Financing constraints and investment-cash flow sensitivity in emerging markets should be analyzed in light of capital market imperfections, financial liberalization and macroeconomic conditions.

This study is expected to serve as a valuable resource for researchers interested in the financing challenges faced by firms in emerging economies.

To the best of the author’s knowledge, this is the first comprehensive systematic and bibliometric literature review that examines the distinct characteristics of the financing constraints hypothesis on investment decisions in emerging markets.