Jingxin Shi

Bio: Jingxin Shi is an academic researcher from Ohio State University. The author has contributed to research in topics: Integral sliding mode & Sliding mode control. The author has an hindex of 5, co-authored 9 publications receiving 4069 citations.

Sliding mode control in electromechanical systems

Abstract: Sliding Mode Control (SMC) is gaining increasing importance as a universal design tool for the robust control of linear and nonlinear systems. The strengths of sliding mode controllers result from the ease and flexibility of the methodology for their design and implementation. They provide inherent order reduction, direct incorporation of robustness against system uncertainties and disturbances, and an implicit stability proof. They also allow for the design of high performance control systems at low costs. SMC is particularly useful for electro-mechanical systems because of its discontinuous structure. In fact, since the hardware of many electro-mechanical systems (such as electric motors) prescribes discontinuous inputs, SMC has become the natural choice for direct implementation. The book is intended primarily for engineers and establishes an interdisciplinary bridge between control science, electrical and mechanical engineering.

Sliding Mode Control in Electro-mechanical Systems

Abstract: Introduction Examples of Dynamic Systems with Sliding Modes Sliding Modes in Relay and Variable Structure Systems Multidimensional Sliding Modes Outline of Sliding Mode Control Methodology Mathematical Background Problem Statement Regularization Equivalent Control Method Physical Meaning of Equivalent Control Existence Conditions Design Concepts Introductory Example Decoupling Regular Form Invariance Unit Control Second-Order Sliding Mode Control Sliding Mode Control of Pendulum Systems Design Methodology Cart Pendulum Rotational Inverted Pendulum (Model) Rotational Inverted Pendulum (Control) Simulation and Experiment Results for Rotational Inverted Pendulum Control of Linear Systems Eigenvalue Placement Invariant Systems Sliding Mode Dynamic Compensators Ackermanns Formula Output Feedback Sliding Mode Control Control of Time-Varying Systems Sliding Mode Observers Linear Asymptotic Observers Observers for Linear Time-Invariant Systems Observers for Linear Time-Varying Systems Observer for Linear Systems with Binary Output Integral Sliding Mode Motivation Problem Statement Design Principles Perturbation and Uncertainty Estimation Examples Summary The Chattering Problem Problem Analysis Boundary Layer Solution Observer-Based Solution Regular Form Solution Disturbance Rejection Solution State-Dependent Gain Method Equivalent Control-Dependent Gain Method Multiphase Chattering Suppression Comparing the Different Solutions Discrete-Time and Delay Systems Introduction to Discrete-Time Systems Discrete-Time Sliding Mode Concept Linear Discrete-Time Systems with Known Parameters Linear Discrete-Time Systems with Unknown Parameters Introduction to Systems with Delays and Distributed Systems Linear Systems with Delays Distributed Systems Summary Electric Drives DC Motors Permanent-Magnet Synchronous Motors Induction Motors Summary Power Converters DC/DC Converters Boost-Type AC/DC Converters DC/AC Converter Summary Advanced Robotics Dynamic Modeling Trajectory Tracking Control Gradient Tracking Control Application Examples Automotive Applications Air/Fuel Ratio Control Camless Combustion Engine Observer for Automotive Alternator

Integral sliding mode in systems operating under uncertainty conditions

Abstract: The paper generalized a new sliding mode design concept, namely integral sliding mode (ISM). The order of the motion equation in ISM is equal to the order of the original system, rather than reduced by the number of dimension of the control input. As the result, robustness of the system can be guaranteed throughout an entire response of the system starting from the initial time instance. Uniform formulations of the ISM design principle are developed in the paper. It is shown through examples that our generalized ISM scheme enables a wide scope of application areas. In the case that the given control matrix can not be used directly for generating the sliding mode, the associated decoupling problem was also discussed based on the concept of sliding mode transformation. To alleviate chattering, we remove the discontinuous control action from the real control path and insert it to an internal dynamic process for generating the sliding mode.

Sliding-Mode Control for Systems With Mismatched Uncertainties via a Disturbance Observer

Abstract: This paper develops a sliding-mode control (SMC) approach for systems with mismatched uncertainties via a nonlinear disturbance observer (DOB). By designing a novel sliding surface based on the disturbance estimation, a DOB-based SMC method is developed in this paper to counteract the mismatched disturbance. The newly proposed method exhibits the following two attractive features. First, the switching gain is only required to be designed greater than the bound of the disturbance estimation error rather than that of the disturbance; thus, the chattering problem is substantially alleviated. Second, the proposed method retains its nominal performance, which means the proposed method acts the same as the baseline sliding-mode controller in the absence of uncertainties. Simulation results of both the numerical and application examples show that the proposed method exhibits much better control performance than the baseline SMC and the integral SMC (I-SMC) methods, such as reduced chattering and nominal performance recovery.

Toward a Fully Autonomous UAV: Research Platform for Indoor and Outdoor Urban Search and Rescue

Abstract: Urban search and rescue missions raise special requirements on robotic systems. Small aerial systems provide essential support to human task forces in situation assessment and surveillance. As external infrastructure for navigation and communication is usually not available, robotic systems must be able to operate autonomously. A limited payload of small aerial systems poses a great challenge to the system design. The optimal tradeoff between flight performance, sensors, and computing resources has to be found. Communication to external computers cannot be guaranteed; therefore, all processing and decision making has to be done on board. In this article, we present an unmanned aircraft system design fulfilling these requirements. The components of our system are structured into groups to encapsulate their functionality and interfaces. We use both laser and stereo vision odometry to enable seamless indoor and outdoor navigation. The odometry is fused with an inertial measurement unit in an extended Kalman filter. Navigation is supported by a module that recognizes known objects in the environment. A distributed computation approach is adopted to address the computational requirements of the used algorithms. The capabilities of the system are validated in flight experiments, using a quadrotor.

Consensus Tracking of Multi-Agent Systems With Lipschitz-Type Node Dynamics and Switching Topologies

Abstract: Distributed consensus tracking is addressed in this paper for multi-agent systems with Lipschitz-type node dynamics. The main contribution of this work is solving the consensus tracking problem without the assumption that the topology among followers is strongly connected and fixed. By using tools from M-matrix theory, a class of consensus tracking protocols based only on the relative states among neighboring agents is designed. By appropriately constructing Lyapunov function, it is proved that consensus tracking in the closed-loop multi-agent systems with a fixed topology having a directed spanning tree can be achieved if the feedback gain matrix and the coupling strength are suitably selected. Furthermore, with the assumption that each possible topology contains a directed spanning tree, it is theoretically shown that consensus tracking under switching directed topologies can be achieved if the control parameters are suitably selected and the dwell time is larger than a positive threshold. The results are then extended to the case where the communication topology contains a directed spanning tree only frequently as the system evolves with time. Finally, some numerical simulations are given to verify the theoretical analysis.

New methodologies for adaptive sliding mode control

Abstract: This article proposes new methodologies for the design of adaptive sliding mode control. The goal is to obtain a robust sliding mode adaptive-gain control law with respect to uncertainties and perturbations without the knowledge of uncertainties/perturbations bound (only the boundness feature is known). The proposed approaches consist in having a dynamical adaptive control gain that establishes a sliding mode in finite time. Gain dynamics also ensures that there is no overestimation of the gain with respect to the real a priori unknown value of uncertainties. The efficacy of both proposed algorithms is confirmed on a tutorial example and while controlling an electropneumatic actuator.

A survey of applications of second-order sliding mode control to mechanical systems

Abstract: The effective application of sliding mode control to mechanical systems is not straightforward because of the sensitivity of these systems to chattering. Higher-order sliding modes can counteract this phenomenon by confining the switching control to the higher derivatives of the mechanical control variable, so that the latter results are continuous. Generally, this approach requires the availability of a number of time derivatives of the sliding variable, and, in the presence of noise, this requirement could be a practical limitation. A class of second-order sliding mode controllers, guaranteeing finite-time convergence for systems with relative degree two between the sliding variable and the switching control, could be helpful both in reducing the number of differentiator stages in the controller and in dealing with unmodelled actuator dynamics. In this paper different second-order sliding mode controllers, previously presented in the literature, are shown to belong to the above cited class, and some cha...