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The finite-time visual servoing control problem is considered for dynamic wheeled mobile robots (WMRs) with unknown control direction and external disturbance.

By using finite-time control method and switching design technique.

First, the visual servoing kinematic WMR model is developed, which can be converted to the dynamic chained-form systems by using a state and input feedback transformation. Then, for two decoupled subsystems of the chained-form systems, according to the finite-time stability control theory, a discontinuous three-step switching control strategy is proposed in the presence of uncertain control coefficients and external disturbance.

A class of discontinuous anti-interference control method has been presented for the dynamic nonholonomic systems.

The purpose of this paper is to obtain the criteria of p‐moment exponential robust stability for a class of grey neutral stochastic delay systems.

By constructing a Lyapunov‐Krasovskii functional and employing the decomposition technique of continuous matrix‐covered sets of grey matrix and using three key inequalities, the paper investigates the p‐moment exponential robust stability for a class of grey neutral stochastic delay systems. A numeric example is given to demonstrate the effectiveness of the criteria presented in the paper.

The results not only can be used to judge the p‐moment exponential robust stability of the systems researched in the paper, but also can be applied in the stability analysis of grey non‐neutral stochastic systems.

The method exposed in the paper can be used in the analysis and designation of practical stochastic control systems.

The paper succeeds in obtaining the criteria of p‐moment exponential robust stability for grey neutral stochastic delay systems by constructing a Lyapunov‐Krasovskii functional and employing the decomposition technique of continuous matrix‐covered sets of grey matrix and using three key inequalities.

This paper aims to make an industrial robot intelligently and remotely cooperate with humans to work in unknown unstructured environments.

Presents a bilateral adaptive teleoperation control approach involving a contact force driven compensation with an auto‐switching function, which utilizes a biologically motivated compliance function. Based on sensed contact force, the switching function can adjust its slave control input to decide how much robotic intelligences should intervene in the system by switching modes. Other schemes for robotic intelligence, robotic impedances and compensators, are investigated to guarantee good transparency without warranting human error and maintain a stable contact, based on the force feedback, in constrained motion while a communication delay exists.

The simulation and experimental results demonstrate transparency and contact stability in the presence of constant and time‐varying communication delays, respectively. The proposed bilateral adaptive teleoperation control method outperforms three other techniques.

This paper introduces an adaptive teleoperation control method with local robotic intelligence assistance. The developed method does not modify the existing designs of industrial robots. The contact force and position and force errors are well controlled to obtain a stable contact and transparency, through adaptation of robotic impedances.

The purpose of this paper is to investigate the dynamic stability of liquid hydrogen turbopump rotor system in rocket engine under the effects of seal and internal rotor damping.

The dynamic modeling of a liquid hydrogen turbopump rotor system in rocket engine is presented in this paper with the aid of the finite element technique. The mathematical model takes into account the seal hydrodynamic forces described by Muszynska model and the internal rotor damping, viscous damping, and hysteretic damping. The shooting method and Floquet theory are employed to investigate the effects of seal and internal rotor damping on the nonlinear dynamic stability of two turbopump designs, the original and the modified design with a flexible bearing support.

The numerical results, which are in good agreement with test data, show that the destabilizing effect of internal rotor damping play a key role in the original design. In the modified design, the stability margins are enhanced and the vibration response levels are minimized. The onset speed of instability increases in original design and decreases in modified design as the effects of seal nonlinearities are considered. The predicted results indicate that the seals have a great destabilizing effect in the modified design and the turbine end bearing is the most dangerous hardware in both designs. The system stability analysis shows that the effect of seal length on the system stability is significant comparing with that of seal radius.

The results can be used in the design and operation of a liquid hydrogen turbopump rotor system to improve its stability performance and eliminate its subsynchronous problem.

Since seal and internal damping are two key destabilizing factors in liquid hydrogen turbopumps and the seal nonlinearities are inevitable, the use of nonlinear theory to study their effects on nonlinear stability and dynamic performance can lead to accurate prediction and explain the nature of the subsynchronous motion.

This paper aims to provide detailed information on the dynamic model and closed‐loop control theory for a resonant accelerometer based on electrostatic stiffness, which is important for the design of this type of resonant accelerometer.

After analysing the principles of the resonant accelerometer based on electrostatic stiffness, a dynamic model was built. According to the requirements of the closed‐loop control, the control equations based on phase‐locked technology were also built for the system. With the help of the averaging method, the system behaviour was analysed, and the equilibrium for the vibration amplitude was achieved.

The theoretical analysis and simulation show that integral gain is critical to system stability. When it is larger than the critical point, the system stable time is shorter, but the frequency‐tracking process fluctuates; if it is smaller than the critical point, the system stable time is longer, and the frequency‐tracking process stabilizes a resonant accelerometer was fabricated with a bulk‐silicon‐dissolved process. With the above conclusions, the accelerometer was driven and tested with a sensitivity of 47 Hz/g for a single vibration beam.

The dynamic model and the control theory for the resonant accelerometer based on electrostatic stiffness were presented in this paper. The simulation and experiment results agree well with the theoretical analysis.

This paper aims to use a new design approach based on a Lagrange mean value theorem for the stabilization of multivariable input‐delayed system by linear controller.

The delay‐dependent asymptotical stability conditions are derived by using augmented Lyapunov‐Krasovskii functionals and formulated in terms of conventional Lyapunov matrix equations and some simple matrix inequalities. Proposed design approach is extended to robust stabilization of multi‐variable input‐delayed systems with unmatched parameter uncertainties. The maximum upper bound of delay size is computed by using a simple optimization algorithm.

A liquid monopropellant rocket motor with a pressure feeding system is considered as a numerical design example. Design example shows the effectiveness of the proposed design approach.

The proposed approach can be used in the analysis and design of the uncertain multivariable time‐delay systems.

The paper has a great potential in the stability analysis of time‐delay systems and design of time‐delay controllers and may openup a new direction in this area.

Analysis of stability of slopes has been the subject of many research works in the past decades. Prediction of stability of slopes is of great importance in many civil engineering structures including earth dams, retaining walls and trenches. There are several parameters that contribute to the stability of slopes. This paper aims to present a new approach, based on evolutionary polynomial regression (EPR), for analysis of stability of soil and rock slopes.

EPR is a data‐driven method based on evolutionary computing, aimed to search for polynomial structures representing a system. In this technique, a combination of the genetic algorithm and the least square method is used to find feasible structures and the appropriate constants for those structures.

EPR models are developed and validated using results from sets of field data on the stability status of soil and rock slopes. The developed models are used to predict the factor of safety of slopes against failure for conditions not used in the model building process. The results show that the proposed approach is very effective and robust in modelling the behaviour of slopes and provides a unified approach to analysis of slope stability problems. It is also shown that the models can predict various aspects of behaviour of slopes correctly.

In this paper a new evolutionary data mining approach is presented for the analysis of stability of soil and rock slopes. The new approach overcomes the shortcomings of the traditional and artificial neural network‐based methods presented in the literature for the analysis of slopes. EPR provides a viable tool to find a structured representation of the system, which allows the user to gain additional information on how the system performs.

This paper studies the stability properties of a class of nonlinear output‐feedback control system. By using a control transform and constructing Liapunov function, the sufficient conditions of the asymptotic stability for the nonlinear control system are presented. The result in this paper includes some existing results.

To present which properties of social systems can be used in studying and determining their broadly defined security. A core concept of security is to be developed into a typology of attributes of security of social systems.

The interpretation of security has become one of the most important challenges of theory of international relations and of related areas. Unfortunately, theory only follows the processes and provides descriptions and interpretations. Explanations are rare or superficial. Predictions or normative approaches, essential for security considerations, are mainly embedded either in ideological discourse or in common sense conclusions. A broadly defined systems thinking is applied as an instrument allowing for enhancement of methodology of security research in dealing with complex social phenomena.

It may not be expected that systems thinking could provide all the answers to the questions arising in security theory and policy. At the same time, it can be shown how strongly the discourse on a broadly defined security, not only in international relations, has been influenced by systems thinking.

It is but an introductory survey study and includes omissions and simplifications that have to be explained in detail in further studies.

An introduction to the further research on the links between systems thinking and discourse on broadly defined security of individuals and social systems.

Allows systems specialists to avoid simplifications in understanding social systems and at the same time helps security specialists to avoid abuses and trivialization of systems thinking.

A suspended wheeled mobile robot (SWMR) that consists of one or more manipulators can be exploited in various environmental conditions such as uneven surfaces. The purpose of this paper is to discuss the requirements for stable motion planning of such robotic systems to perform heavy object manipulation tasks.

First, a systematic procedure for dynamics modelling of such complicated systems for planar motion is presented and verified using ADAMS simulation software. Next, based on the new dynamic moment‐height stability (MHS) measure, the stability of such systems will be investigated using the obtained dynamics. To this end, introducing the concept of a virtual frame, the obtained model of SWMR has been employed for investigating the effect of the base suspension characteristics as well as terrain roughness on the stability of the system. Next, the stability evaluation of the system is investigated after toppling down which has been rarely addressed in the literature. In addition, using the aforementioned model, the effect of stiffness is examined after instability.

First, a systematic procedure for dynamics modelling of such complicated systems for planar motion is presented and verified using ADAMS simulation software. Next, based on the new dynamic MHS measure, the stability of such systems will be investigated using the obtained dynamics. To this end, introducing the concept of a virtual frame, the obtained model of SWMR has been employed for investigating the effect of the base suspension characteristics as well as terrain roughness on the stability of the system. Next, the stability evaluation of the system is investigated after toppling down which has been rarely addressed in the literature. In addition, using the aforementioned model, the effect of stiffness is examined after instability.

A general procedure for dynamics modelling of SWMRs is presented. To verify the obtained dynamics model, another model for the considered system has been developed by ADAMS software. Next, using the obtained dynamics, the postural stability of such systems is investigated, based on the new postural MHS measure extended for SWMRs. The obtained simulation results show that by decreasing the stiffness coefficients of suspension subsystem the stability of the system weakens.