A hybrid controller design for complex network systems with hybrid automaton-based convergence analysis

Control of manipulators during execution of tasks that require the end‐effector to come into contact with objects in its work environment represents an important class of control problem. Hybrid control, a concept which defines the architecture of a class of control laws has been proposed as a method with which to solve this control problem. One interpretation of the hybrid control method is within the framework of constrained motion control. Constrained motion occurs during contact by the manipulator end‐effector with rigid objects in the workplace, hence the motion of the manipulator is kinematically constrained. Papers have appeared in the robotics control literature addressing hybrid control within the constrained motion context which do not explicitly use the constrained dynamic formulation that correctly describes the dynamic behaviour of the manipulator. This article serves to link results from constrained motion control and the existing literature on the hybrid control method. In this article a formulation of the constrained manipulator dynamics is presented in which the hybrid control design is most naturally carried out. This formulation of the manipulator dynamics, previously proposed in the robotics literature, is such that the generalized force and position coordinates to be controlled are mutually orthogonal. Hence, the hybrid selection matrices, a key element of the hybrid control design philosophy, are implicit in this coordinate representation. A hybrid control design methodology is then formulated based on this development. Two hybrid control laws are proposed. For each hybrid control law, the global asymptotic stability is readily established due to the natural coordinate representation. One of these hybrid control laws, a constrained motion control law already proposed in the literature, is given to illustrate the equivalence of the hybrid control design and certain existing constrained motion control methods. Finally, a concrete example of a three‐degree‐of‐freedom robotic manipulator illustrates the hybrid design methodology proposed.

ABSTRACTThis paper addresses the control problem of an important class of hybrid dynamical systems where the desired state does not belong to the set of subsystem equilibria. Beyond the practical stabilisation where the system trajectory has to be driven to a neighbourhood of a desired state, a control law is designed to solve the limit cycle stabilisation problem for planar hybrid systems. Using the hybrid Poincaré map, two hybrid controllers are developed, which guarantee a local asymptotic/finite-time stability of the desired limit cycle. Illustrative examples are provided to highlight the effectiveness of the derived results.

Research of modern flight control methods for unmanned aerial vehicle (UAV), which brings benefits of lowering the cost and risk associated with the design of actual physical flight systems, has become research hotspot in recent years. However, controller design for UAV is complicated and challengeable due to UAV uncertainties, nonlinearity and coupling. This paper presents a new hybrid controller design scheme, which consists of inner-loop controller and outer-loop controller. The Inner-loop controller realizes linearization and decoupling of flight systems by employing feedback linearization, which establishes direct relationship between the desired UAV output and moment instead of traditional fast and slow dynamics. For further consideration of uncertainties, such as unmodeled dynamics and external disturbances, The outer-loop controller is designed to realize the robustness of flight systems by using μ- synthesis approach. Numerical simulation shows that UAV equipped with the hybrid controller has weaker conservation and a stronger ability to resist disturbances.

A numerical method for hybrid optimal control based on dynamic programming

The design of engine control systems has been traditionally carried out using a mix of heuristic techniques validated by simulation and prototyping using approximate average-value models. However, the ever increasing demands on passengers' comfort, safety, emissions, and fuel consumption imposed by car manufacturers and regulations call for more robust techniques and the use of cycle-accurate models. We argue that these models must be hybrid because of the combination of time-domain and event-based behaviors. We present a hybrid model of the engine in which both continuous and discrete time-domain as well as event-based phenomena are modeled in a separate but integrated manner. Based on this model, we formalize the specification of the overall engine control by defining a number of hybrid control problems. To cope with the difficulties arising in the design of hybrid controllers, a design methodology is proposed. This methodology consists of a relaxation of the hybrid problem by simplifying some of its components to obtain a solvable problem,and then deriving a solution to the original control problem by appropriately modifying the control law so obtained to take into consideration the original specifications and models. The effectiveness of this approach is illustrated on three challenging problems: fast force-transient control, cutoff control, and idle speed control.

: Controls research under this program concentrated on the development of a network thermodynamic stabilization framework for hybrid control design of large-scale and multiagent aerospace systems. In particular, we concentrate on hybrid control, hierarchical control, impulsive dynamical systems, nonnegative dynamical systems, compartmental systems, large-scale systems, nonlinear switching control, cooperative control, and adaptive control. Application areas include large flexible interconnected space structures, spacecraft stabilization, cooperative control of unmanned air vehicles, network systems, swarms of air and space vehicle formations, and pharmacological systems.

This paper presents the design of an adaptive hybrid controller for linear switched reluctance motor (LSRM) to be used in pick and place industrial applications. The hybrid controller consists of two main controllers, the proportional-derivative controller (PDC) and the fuzzy logic controller (FLC). In this paper, the proposed Adaptive hybrid PD-fuzzy logic controller (AHPDFLC) uses, at the beginning, the adaptive PDC (APDC) for coarse position error while for fine position error the position control process is achieved using conventional FLC. This hybrid controller exploits the advantages of both controllers, APDC which can vary its gains online to avoid the overshoot problems and FLC which can decrease the steady-state error to roughly zero value to get an acceptable position tracking response of the underlying LSRM. The adaptivity of the hybrid controller refers to the variation of PDC's proportional and derivative gains to adapt a wide range of loading conditions i.e. a specific reference position signal, load force, mover mass, friction constant, applied dc voltage and phase resistance. PDC gain scheduling is achieved online based on fuzzy rules and reasoning. The results of AHPDFLC are compared with the results of non-adaptive position controllers. This comparison between different position controllers' response verifies the simplicity and the effectiveness of the proposed adaptive hybrid position controller for a wide range of variable loading conditions. Finite Element Method Magnetics (FEMM) and MATLAB/Simulink simulation programs are used throughout the paper to model the different modules of LSRM to prove the validity of this position controller approach on simulation environment.

Hybrid control for non-overshooting step responses of linear systems

In this article, a unique and innovative design for addressing the speed synchronization problem in a multi-motor system using Brush less DC (BLDC), motors is presented by utilizing motor back emf equation and rotor position commonly called sensor less technique. In the proposed method, the system is modelled as a consensus problem of leader following multi-agent system (MAS), and a hybrid controller is designed by using Model Reference Adaptive Control (MRAC) along with Variable Structure (VS) control technique of Sliding Mode Control (SMC), herein called Variable Structure Model Reference Adaptive Control (VS-MRAC). The consensus algorithm of MAS (reformed w.r.t motor speed data), is fused with the hybrid controller to reach consensus on speed regulated by proposed hybrid controller. The stability of a system is endorse by designing a Lyapunov function. The efficiency of the proposed methodology is proven by simulations performed in MATLAB and the acquired results validate the success of proposed design methodology.

Friction observer-based hybrid controller for a seat suspension with semi-active electromagnetic damper

This paper presents a vision based Cart-Inverted Pendulum (CIP) system under a hybrid feedback configuration: the continuous cart’s position measured by encoder and the delayed & sampled inverted pendulum’s upper coordinates, obtained from a visual sensor. The challenge here is to stabilize the CIP from a big inclined initial angle by using a low cost CCD camera. Under this scheme, we propose a hybrid control which consists in a Jumpingup (Bang-Bang) control and a two causal stabilization loops control: the first one (inner loop) realizes a linearization and the stabilization control of the pendulum based on an innovative Piecewise Continuous Reduced Order Luenberger Observer coupled with a linearization module, the second one (the outer loop) realizes a Lyapunov based control for the unstable internal system with lower dynamics than that of the pendulum. This hybrid control method is capable of balancing the CIP system within small cart’s displacement. Performances issues of the proposed method are illustrated by the experimental figures and videos.

This paper presents an averaged model and a small-signal model of a bidirectional dual active bridge (DAB) DC-DC converter. Based on the proposed model, the stability and transient power flow in the system can be analyzed. A novel hybrid controller is proposed for the phase-shift based feed-back and feed-forward control of a 600V/10kW prototype. The hybrid controller can ease the difficulties of the parameter selection of a traditional PI. The effectiveness of the models and proposed hybrid controller are validated by simulations and experiments in both transient and steady state operations.

In the last two decades, there have been great advances in using Unmanned Aerial Vehicles (UAVs) in several applications. This rapid growth is due to their ability to carry out several types of tasks with high flexibility aligned with reduced risks to human life and cost-effectiveness. The increasing demands for more complex assignments have improved UAVs' capabilities, propelling the rise of platforms with a high degree of autonomy for performing simultaneous tasks with less human intervention. One of the great challenges of maneuvering a UAV for a stabilized flight consists of a highly-coupled nonlinear system with fast dynamics. Thus, attitude control is an essential issue for stabilizing the vehicle or for keeping it in the desired orientation. The PID controller is often used due to its simple structure, good stability properties, and less dependence on the exact system model. However, its tuning process may become complicated in the face of the system nonlinearities. In this scenario, an adjustment error can cause it to lose its flight stability. Therefore, the main contribution of this work is the development of a Fuzzy-PID hybrid controller to control a quadrotor UAV's height stability. The work also considers a classic PID controller for comparison purposes with the proposed hybrid controller. The ROS/Gazebo platform was used to carry out the experiments with both control structures. From the results, it was possible to verify that both PID and Fuzzy-PID controllers could perform the attitude control of the UAV. However, the hybrid control strategy obtained some advantages, such as self-adjustment through system variations.

This study proposes a hybrid control methodology that combines tuned liquid damper (TLD) and active mass damper (AMD) to suppress vibrations of multi-story building structure effectively. To this end, a dynamic model that can predict the vibration of multi-story building structure coupled with TLD and AMD is derived using the energy approach. The TLD that is mainly designed to suppress the main natural mode is developed with a multi-degree-of-freedom model to investigate the effect of the TLD on natural modes of structure numerically. The AMD is an active vibration controller that can suppress remaining resonant peaks, including ones resulting from the application of the TLD as well as other higher modes of interest. In this way, the proposed control can utilize the advantages of TLD and AMD simultaneously. We set up an experimental apparatus to verify the performance of the hybrid control methodology. The numerical and experimental results show that the proposed hybrid control method can successfully suppress the vibrations of multi-story building structure. The dynamic model derived in this study can also accurately predict the actual behavior of the system.

Power supply system significantly impact the endurance capabilities and operational reliability of unmanned underwater vehicles (UUVs). Due to the battery-based power supply architecture of UUV systems, input voltage fluctuations are inherent to the system, making conventional variable frequency modulation (VFM) ineffective in maintaining optimal efficiency across the full operating range. To address this issue, a VFM plus phase shift modulation (PSM) hybrid control strategy based on simplified state-plane analysis is proposed in this article. This approach facilitates smooth transitions between VFM and PSM while maintaining robust dynamic response. Furthermore, an optimal parameter design method for implementing the hybrid control strategy has been developed, and a voltage balancing method to resolve the inherent input capacitor voltage imbalance in series half bridge three level (SHBTL) <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LLC</i> resonant converters has been introduced. The efficacy of the proposed methods is validated through experimental testing on a 3 kW prototype. Experimental results demonstrate superior performance in terms of efficiency, dynamic response, and voltage balancing across the entire operational range.