Model Decoupled Synchronization Control Design with Fractional Order Filter for H-Type Air Floating Motion Platform.

This paper proposes a method that based on direct thrust control (DTC) to address the disturbance rejection problem in permanent magnet linear synchronous motor (PMLSM). In view of the PMLSM, direct torque control design is suitable for the DTC of linear motor control system. According to the rated load capacity of the motor, we give PMLSM a load disturbance. Then we obtain the motor dynamic characteristics which are analyzed from the simulation. Finally, the simulation results show that: the PMLSM control system that based on DTC has stronger robustness and better performance of disturbance rejection.

Dynamic analysis, electrical coupling and synchronization control of the conformable FitzHugh-Nagumo neuronal models have been presented in this work. Firstly, equations of the Adomian-Decomposition-Method and conformable neuron model have been introduced. The Adomian-Decomposition-Method has been employed for the numerical simulation analysis, since it converges fast and provides serial solutions. Fractional order and external current stimulus have been considered as bifurcation parameters and their effects on neuron model dynamics have been examined in detail. Then, the electrical coupling of the two conformable neuronal models without any controller has been revealed and the significance of the coupling strength parameter has been evaluated. To eliminate impact of the coupling strength parameter on synchronization status of neurons, Lyapunov control method has been employed for synchronization control. In the last step, the numerical simulation studies have been experimentally verified using the Texas Instrument Delfino digital signal processor board. Numerical simulation results together with experimental validation have showed that the types of dynamics of the related neuron model are not affected from the change of the fractional order of conformable derivative, but the frequency of the dynamic response of the neuronal model is changed from the alteration of the fractional order. The frequency of response of the neuron model increases with decreasing values of the fractional order. On the other hand, if there is no synchronization control method, the coupled neuron models exhibit response ranging from synchronous to asynchronous depending on the sign and value of the coupling parameter. Additionally, decreasing values of the fractional order may allow the coupled neurons to enter the synchronous state more quickly due to increasing frequency of response of the neuronal model. Finally, the coupled neuron models could exhibit synchronous behavior, that is determined by calculating the standard deviation results, regardless of the value of the coupling parameter by using the Lyapunov control method.

This paper discusses feedback control design problem for leader-to-formation systems which could include one leader and one follower. The performance of the leader is measured by energy of the error between its output and reference while the performance of the follower is measured by the energy of the error between the distance from the leader to the follower and the desired distance. In this paper, a sub-optimal two degree of freedom (2DOF) control design method is presented by applying H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and Hinfin control design. Upper bounds of the cost functions for both of leader and follower are minimized. Numerical example illustrates that the presented controllers have good performance in disturbance rejection and formation control.

Nowadays, linear motors are widely used in machine tools to eliminate the gear re-lated problems of rotative drives with lead-screw transmission. With linear motors the performance increases considerably since mechanical transmission elements are re-moved. This leads to a better precision, a higher acceleration and a higher speed of the moving part. Therefore, direct drives with linear motors are increasingly used in indus-trial applications although these solutions often need higher investment costs. In industrial processing plants, raw materials are transferred into the production process, typically then they pass several processing stations and finally, the processed article is removed from the processing chain. In today’s production plants, different equipment is used for transportation and processing materials. Advantages can be ex-pected by using the same system of linear drives for transportation as well as for proc-essing materials. Hence, this dissertation discusses a proposal for process-integrated material handling based on linear drives. The integration of linear drives into the pro-duction plant calls for a new view of the production process. The integrative viewpoint where a co-design of drive and plant is introduced should be developed for future appli-cations. To fulfill the demand of a material handling system, two alternatives are compared. The first one is based on active vehicles and passive tracks and the second one is based in passive vehicles and active tracks. Advantages and disadvantages of both alternatives are discussed, considering aspects of the power supply system as well as control and communication demands. The control of Long Stator PM Linear Synchronous motors with passive, lightweight transportation units is investigated in detail. Hard- and software for an experimental setup is developed for a sectioned Long Stator Linear Motor and used to validate the proposed system. Finite Element tools are applied to introduce information into the con-trol loop about section’s transition and thrust force ripple. Field oriented control, direct flux control and resonant control are supported by the Finite Element information to suppress detent forces and achieve a smooth movement overall the track. A control method for soft transition between separately fed sections of the track without affecting the dynamic are implemented. Experimental results validate the proposed system and it opens a new application area for the linear drives in future.

An internal model control with inverted decoupling (ID-IMC) controller design method based on equal fractional Butterworth (EFBW) filter is proposed for Multiple Input-Multiple Output (MIMO) systems with multiple time delays and Right Half Plane (RHP) zeros. There has been finite memory and limited flexibility for multivariable processes developed using a direct ID-IMC method. This paper presents a novel procedure to approximate Butterworth (BW) filters using fractional-order (FO) theories, so that the degree-of-freedom for tunable parameters is increased. The proposed ID-IMC controller cascaded with EFBW filter combines the computational simplicity of the ID-IMC structure with the greater flexibility of the EFBW filter, in conjunction with a better set-point tracking and disturbance rejection performance. Further, the stability analysis of the designed controller is given to ensure the stability of the closed-loop system. Dynamic performance indicators and sensitivity functions are carried out for the time domain and robustness analysis. Two illustrative examples are presented to show the merits of the proposed method.

Evaluating the effectiveness of several synchronization control methods applying to the electrically and the chemically coupled hindmarsh-rose neurons

This paper describes the methods and experiments on synchronous steering control of a parallel bicycle which has twin wheels on the outside of the parallel driving axes and an inverted-pendulum-type upper structure. The bicycle can be steered by controlling rotation of each wheel driven by each DC servo-motor. In order to drive the vehicle along an arbitrary path, both wheels must be steered and synchronously controlled. Both synchronous control methods are proposed. A gain changing method and a servo-reference method are each applied for the servo-control. The steering and driving control of the vehicle has been attained by using synchronous servo-control methods through a microcomputer. Experiments show that the control methods proposed here are available for steering and servocontrol without losing stability of the vehicle.

This paper describes the methods and experiments on synchronous steering control of a parallel bicycle which has twin wheels on the outside of the parallel driving axes and an inverted-pendulum-type upper structure. The bicycle can be steered by controlling rotation of each wheel driven by each DC servo-motor. In order to drive the vehicle along an arbitrary path, both wheels must be steered and synchronously controlled. Both synchronous control methods are proposed. A gain changing method and a servo-reference method are each applied for the servo-control. The steering and driving control of the vehicle has been attained by using synchronous servo-control methods through here are available for steering and servo-control without losing stability of the vehicle.

Research on the fractional order system is becoming more and more popular. Most of the fractional order controller design methods focus on single-input-single-output processes. In this paper, a fractional order internal model controller with inverted decoupling is proposed to handle non-integer order two-input-two-output systems with time delay. The fractional order two-input-two-output (FO-TITO) process is decoupled by inverted decoupling method. The fractional order internal model control (IMC) is then used to simplify the tuning process. Because of the complexity of multiple time delay, the condition of FO-TITO process with time delay is discussed. In order to ensure the robustness of the system, a Maximum sensitivity function is used to tune the parameters. Then Lyapunov stability theory is applied to verify the stability of the system. The proposed controller provides ideal performance for both set point-tracking and disturbance rejection and is robust to process gain variations. Numerical results show the performance of the proposed method.

Mechatronic systems play an important role in many industrial production facilities and consumer products. To attain desired dynamic responses of these systems, proper design of the embedded feedback control systems is essential. Ever increasing performance demands, however, put a severe challenge to the available methodologies to design these controllers. To meet design specifications of next generation motion systems, control design methodologies are required that explicitly take the multivariable nature of multi-degree-of-freedom motion systems into account while guaranteeing robust performance and stability in the presence of plant variations or uncertainties. Norm-based controller design offers a methodology to deal with these design specifications via the framework of generalized plants. Existing norm-based controller synthesis methodologies, however, have to rely on a parametric model of the system at hand. The plant identification process, required to obtain such a model, can be seen as a bottleneck in the practical applicability of norm-based controller design procedures. On the other hand, the dynamic responses of high performance motion systems can be well predicted via non-parametric descriptions such as frequency response data samples or impulse responses. This research presents a methodology to perform norm-based controller design based on frequency response data samples of the plant directly. To come up with such a methodology, the underlying phenomena that are inherent to limited availability of samples are studied and alternative criteria for stability and performance are posed that can be evaluated based on data samples only. An overview of the main results described in the thesis is given.A novel data-based stability test is proposed that enables validation of stability of a system based on frequency response samples only. This test is well suited for numerical evaluation and does not rely on knowledge about the number of unstable open-loop poles. Research efforts have been focussed to bridge the gap between a finite number of samples, and the set of all possible underlying frequency responses. It appears that sampling theory, well known in the context of harmonic decompositions of time domain signals, can be generalized towards the analysis of sampling of transfer functions. By combining analytical properties of transfer functions with this sampling framework, an explicit expression for the set of all frequency responses is given in terms of the available prior knowledge about the system. Two controller design approaches are proposed. As a first case, the H2 controller synthesis problem is considered. By composing the Youla parameter from a set of stable basis functions, the H2 controller synthesis problem can be rendered into a least squares optimization problem that can be solved via available tools. The performed analysis, however, shows that controller synthesis based on a frequency sampled performance criterion, unavoidably induces inter-frequency-grid performance degradation. Practical means to reduce this effect are given. Furthermore, a robust stability criterion is posed in terms of the Youla parameter that assures robustness with respect to plant uncertainty and therefore eliminates the usual assumption that infinitely many data samples are available. Alternative to the data-based H2 problem, fixed structure controller parameter optimization is considered. A two-step optimization algorithm is posed that sequentially focusses on stability and performance optimization via a steepest descend algorithm. A novel cost function is introduced that enables convergence from a destabilizing controller parameter set to a stable parameter set. For performance optimization, the gradient of the maximum singular values with respect to the controller parameters is found via a linearization approach. This approach enables to optimize the coefficients of a given fixed structure controller with respect to the H1 norm of the closed-loop system. The proposed data-based controller design methodology is evaluated on frequency response data samples that are obtained from an experimental setup. This validates the proposed stability test and illustrates the effectiveness of the proposed approach for fixed structure controller optimization.

In order to satisfy the requirements of flight control system about command tracking performance, disturbance rejection performance and robustness, a fractional order two-degrees-of-freedom PID control technology is introduced in pitch control system design of UAV. A given value filter type fractional order two-degrees-of-freedom PID controller which consists of the given value filter and the fractional order PID (FOPID) controller is proposed. In the fractional order PID controller design, Nelder-Mead's simplex method is adopted to ensure the control system has the best disturbance rejection performance and robustness, and during the design of the given value filter, a particle swarm optimization (PSO) algorithm is used to make the control system satisfy the requirements of the command tracking performance. The simulation result shows that the designed pitch control system has good control qualities and robustness.

This Letter has proposed a synchronous control strategy of dual five‐level converters based on the improved space vector pulse‐width modulation (SVPWM). Firstly, the main topology of the neutral point clamped (NPC) five‐level converter was introduced and its operational principle was analysed. Then, the space voltage vector diagram was offered. Considering the reduction of switching loss, the optimisation of the synthesis method of target voltage vectors and the addition of the neutral‐point potential balancing algorithm can lead to an improved SVPWM strategy for the five‐level converter. The analysis of the switching rules proves that the improved SVPWM has an advantage over the traditional three‐segment SVPWM due to its fewer times of switching. On the basis of the improved SVPWM, a synchronous control method of dual single‐phase five‐level converters is proposed to carry out a real‐time control of the dual five‐level converters through the combinational‐encoding transmission of output pulses. Thus, the synchronous control method can, to a great extent, solve the problems caused by the traditional dual five‐level independent control method, such as high hardware cost, the complexity of control, and poor synchronous performance. Simulations and experiments show that the proposed synchronous control method is feasible and effective.

This paper presents an investigation of direct thrust force control (DTFC) for permanent magnet linear synchronous motor because end-open structure of linear motor causes the special end-effect, which leads to new problems when the direct torque control (DTC) is applied to linear motors. It is theoretically illustrated that the principle of the DTC can be applied to linear motor control, and clear concepts about different reference frames, physical variables and action of voltage vectors are expounded. The special end-effect has been suitably taken so as to get thrust force response performance as good as possible. Simulation results show that the DTFC is effective in linear motor control systems.

Fractional order [proportional derivative] controller for a class of fractional order systems

It is known that analytical manipulation of the time-domain representation of fractional order transfer function is, hitherto, a challenging task. In this study, a controller design methodology based on the direct synthesis design method is proposed using bi-fractional order transfer function as a reference model and certain time-domain criteria. First, an analysis examines the effects of bi-fractional order transfer function parameters, that is, commensurate fractional order, damping ratio and natural frequency, on the system time-domain criteria. This examination has allowed us to set up a relation between damping ratio and commensurate fractional order. Next, a polynomial function fitting is established in order to express the damping ratio in terms of this commensurate order. Bi-fractional-order reference model is regenerated using the above-mentioned relationship. Furthermore, a control design algorithm that utilizes the newly derived bi-fractional order reference model is developed by considering control signal limitations. The proposed fractional order control design method is then compared with globally optimized fractional order proportional-integral-derivative (PID) controllers under the same circumstances and performance index. Finally, the implementation of the proposed controller design algorithm is done on a real-time active suspension system. The results are very satisfactory and incoherent with the simulations.