Stabilisation of hybrid stochastic differential equations by feedback control based on discrete-time observations of state and mode

Mao [10] recently initiated the study of the mean-square exponential stabilisation of continuous-time hybrid stochastic differential equations (SDEs) by the feedback controls based on the discrete-time observations of the state. However, the feedback controls still depend on the continuous-time observations of the mode. Of course this is perfectly fine if the mode of the system is obvious (i.e. fully observable at no cost). However, it could often be the case where the mode is not obvious and it costs to identify the current mode of the system. To reduce the control cost, it is reasonable we identify the mode at the discrete times when we make observations for the state. Hence the feedback control should be designed based on the discrete-time observations of both state and mode. The aim of this paper is to show how to design such a feedback control to stabilise a given hybrid SDE

Robust quantised control of hybrid stochastic systems based on discrete-time state and mode observations

In this paper, the problems of robust quantized feedback control are studied for hybrid stochastic systems based on discrete-time observations of state and mode. All of the existing results in this area design the quantized feedback control based on continuous observations of the state and mode for all time t ≥ 0 (see [23–25]). This is the first paper where we propose to use the quantized feedback control based on discrete-time observations of the state and mode. The key reason for this is to reduce the burden of communication by using not only the quantization (i.e. in the direction of state axis), but also discrete-time observations of state and mode (i.e. in the direction of time axis). Thus, the designed quantized feedback controllers have to be based on the discrete-time observations of state and mode. Clearly, the new quantized feedback controllers are more realistic and cost less in practice. Two examples with computer simulations will be provided to illustrate the effectiveness of the proposed control method

Almost sure stabilization of hybrid systems by feedback control based on discrete-time observations of mode and state

Although the mean square stabilisation of hybrid systems by feedback controls based on discretetime observations of state and mode has been studied by several authors since 2013 (see, e.g., [17,19,27,31]), the corresponding almost sure stabilisation problem has little been investigated. Recent Mao [18] is the first to study the almost sure stabilisation of a given unstable system x(t) = f(x(t)) by a linear discretetime stochastic feedback control Ax([t/τ]τ)dB(t) (namely the stochastically controlled system has the form dx(t) = f(x(t))dt + Ax([t/τ]τ)dB(t)), where B(t) is a scalar Brownian, τ > 0 and [t/τ] is the integer part of t/τ. In this paper, we will consider a much more general problem. That is, we will to study the almost sure stabilisation of a given unstable hybrid system x(t) = f(x(t), r(t)) by nonlinear discrete-time stochastic feedback control u(x([t/τ]τ), r([t/τ]τ))dB(t) (so the stochastically controlled system is a hybrid stochastic system of the form dx(t) = f(x(t), r(t))dt + u(x([t/τ]τ), r([t/τ]τ))dB(t)), where B(t) is a multi-dimensional Brownian motion and r(t) is a Markov chain

Network Security Technology of Intelligent Information Terminal Based on Mobile Internet of Things

In the process of implementing the Internet of Things, the object itself has identity information and identification equipment and encounters difficulties in communication security during the process of entering the network communication. Just like the Internet and wireless sensor networks, there are security issues in information transmission. Therefore, it is of great significance to study the mobile Internet of Things network security technology depression to protect the communication information in the mobile Internet of Things. This paper mainly studies the network security technology of intelligent information terminal based on mobile Internet of Things. This article will analyze and compare the mainstream encryption algorithms of the current mobile Internet and choose a safer and more secure HASH algorithm. We study the flow of key management, key generation, key distribution, verification key distribution, key update, key storage, key backup, and key validity time setting for mobile Internet of Things, using an existing identity cryptosystem. Based on encryption, the design technology of key management and authentication in this paper is improved. Compared with other methods, the storage consumption of this method on GWN is relatively medium. In the initial stage, the storage is 32 bytes, then in registration stage 1, it reaches 84 bytes, in registration stage 2, it is 82 bytes, and then, in the login authentication phase, the number of bytes rose and reached 356 bytes in authentication phase 3. Experimental results show that this protocol has certain advantages in ensuring safety performance

Simultaneous disturbance estimation and fault reconstruction using probability density functions

A new simultaneous disturbance estimation and fault reconstruction design is studied for stochastic distribution system with actuator faults and output disturbances, where the available information is the measured output probability density function (PDF) of the considered system. Based on this framework, the square-root rational B-spline neural network is applied to model the nonlinear dynamic between PDF and input, where the nonlinearity is assumed to meet the Lipschitz conditions with non-predetermined Lipschitz constants. In addition, a robust descriptor observer is designed to estimate the states and disturbances simultaneously. Meanwhile, the maximum admissible Lipschitz constant is derived via convex optimization. Then, a sliding mode scheme is proposed for the designed observer to reconstruct the actuator faults. Finally, a soil particle gradation control (SPGC) is carried out to show the effectiveness of this way

A 3D-Printed Fin Ray Effect Inspired Soft Robotic Gripper with Force Feedback

Soft robotic grippers are able to carry out many tasks that traditional rigid-bodied grippers cannot perform but often have many limitations in terms of control and feedback. In this study, a Fin Ray effect inspired soft robotic gripper is proposed with its whole body directly 3D printed using soft material without the need of assembly. As a result, the soft gripper has a light weight, simple structure, is enabled with high compliance and conformability, and is able to grasp objects with arbitrary geometry. A force sensor is embedded in the inner side of the gripper, which allows the contact force required to grip the object to be measured in order to guarantee successful grasping and to provide the most suitable gripping force. In addition, it enables control and data monitoring of the gripper’s operating state at all times. Characterization and grasping demonstration of the gripper are given in the Experiment section. Results show that the gripper can be used in a wide range of scenarios and applications, such as the service robot and food industry

Fault tolerant tracking of Mars entry vehicles via fuzzy control approach

In this paper, a fault tolerant attitude tracking control scheme is proposed for Mars entry vehicles (MEVs) with disturbances and actuator failures. The original attitude dynamics of MEVs is divided into two subsystems, named as slow subsystem and fast subsystem, respectively. For slow subsystem, the control-like angular velocity command is generated. For fast subsystem, the Takagi-Sugeno (T-S) fuzzy models are used to describe it at first. Based on these, the partial loss of actuator effectiveness with the generated angular velocity problem is transformed into solving the tracking problem with uncertain parameters. Then, a fault tolerant tracking control scheme is proposed by combining fuzzy line-integral Lyapunov function method with robust H∞control approach. The proposed controller design is simple and can guarantee the faulty closed-loop system to be stable with acceptable attenuation level. Finally, the effectiveness of the proposed design method is demonstrated in a MEVs attitude control system subject to loss of actuator effectiveness