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Hybrid ac/dc distribution has attracted much attention recently. This study presents a medium-voltage (MV) hybrid ac/dc distribution consisting of various distributed generations connecting to the ac and dc loads. Coordination control in hybrid ac/dc distribution is a challenging issue to achieve stability especially when there is a load rejection or loss of the generation. A new decentralised control is proposed to coordinate the hybrid ac/dc distribution even when the inter-station telecommunication is not available. A new control is employed at interlinking converter (ILC) to maintain the power balance between ac and dc subgrids, and to ensure that the power quality is maintained in normal operating condition as well as in an extreme abnormal condition such as island mode. Further, a new control strategy is developed in battery storage system (BES) as a backup device to minimise the power fluctuation in the event of the shedding of the loads or generations. Another advantage of the combination of ILC and BES controllers is to provide a multiple slack terminals in both ac and dc grids, which will enhance the stability in the system. Simulation results have shown that the stability performance can be achieved in various operating scenarios.

To enhance the stability of a micro-grid under fault conditions, this paper proposes the coordination control of a superconducting magnetic energy storage (SMES), an active superconducting fault current limiter (SFCL), and distributed generation units via wireless network communications. This coordination control can smoothly separate the micro-grid from the main network in the case of severe or permanent faults, and assist the micro-grid to achieve the fault ride-through (FRT) operation if the fault is minor or temporary. Details on the modeling, control strategy, and network architecture are presented. Moreover, the simulation analysis of a 10-kV class micro-grid including the SMES, SFCL, and photovoltaic generation units is implemented in MATLAB. Concerning the performance evaluation of the coordination control not only the severe and minor faults but also different communication delays are taken into account. The results confirm the effectiveness of the proposed coordination control.

Background Stroke can lead to movement disorders that affect interlimb coordination control of the bilateral upper extremities, especially the hands. However, few studies have investigated the influence of a stroke on bimanual force coordination control between the hands using a quantitative measurement tool, or the relationship of force coordination with paretic upper extremity motor and functional performance. We aimed to investigate these outcomes using a novel measurement device, and analyze the relationship of bimanual force coordination control deficits in both hands with motor and functional performances of the paretic upper extremity in stroke patients. Methods Sixteen healthy adults and 22 stroke patients were enrolled. A novel bilateral hand grip measurement device with two embedded dynamometers was used to evaluate the grip force during a bilateral hand grip-force coordination control task. The alternating time and force applied for coordination with the grip force of both hands were calculated to analyze control of bimanual grip force coordination. Motor and functional measurements included the upper-extremity portion of the Fugl-Meyer assessment (FMA-UE), Wolf Motor Function Test (WMFT), Motor Assessment Scale (MAS), and Barthel Index (BI). Results Compared with the healthy group, the alternating time from the non-paretic to the paretic hand was 27.6% shorter for stroke patients (p

This research focuses on four-wheel-drive electric vehicles. On the basis of the hierarchical coordinated control strategy, the coordinated control system of driving force distribution regulation and differential braking regulation was designed to increase the electric vehicles steering stability under special road working conditions. A seven-degree-of-freedom model of an electric vehicle was established in MATLAB/Simulink, and then a hierarchical coordination control model of the Electronic stability program and dynamic torque distribution control system was established. Adaptive fuzzy control was applied to ESP and, based on the neural network PID control, a torque distribution control system was designed. On the basis of the proposed coordinated control model, a performance simulation and a hardware-in-the-loop test of the control system under the typical working condition of single line shift were carried out. From the final results, it can be seen that the proposed control strategy can greatly improve the safety of the vehicle after serious side slip, increase the stability of the whole vehicle, and effectively increase the vehicle lateral stability.

International audience; This paper is about an innovative type of power plant, called Hybrid Combined Cycle (HCC), and its control, by means of a coordinated-distributed strategy. The considered HCC plant consists of a Combined Cycle Power Plant (CCPP), a concentrated solar plant (parabolic trough) and a thermal storage system (a molten salt two-tank indirect sensible thermal storage), connected together in an original form. The proposed control strategy for such an interconnected plant corresponds to a distributed one, since it relies on pre-specified controllers for each subsystem, and is coordinated meaning here that a coordinator is designed to give the setpoints to each local controller, on the basis of global information and subsystem modeling. After its presentation, this strategy is applied to the considered HCC plant, including its modeling step and then its coordinated control. The approach is illustrated in simulation considering three coordination schemes: one based on LQ design, another one on MPC, and a third one on H∞, and the results are promising in terms of gas consumption reduction while accommodating to power demand and renewable source variations.

With the growth of DC electricity load, the difficulty to improve the power quality, and the increasing penetration of renewable power, flexible DC distribution network, which contains complex renewable energy generation equipment and a large number of power electronic converters, become an important research direction. The modelling of the DC distribution network is an essential step for the research on the coordination control. However, the traditional modelling will be a burden for simulation software. This article models all electrical devices as equivalent power sources based on the proportional–integral control and the power–voltage curve, ignoring the complex internal control processes. Based on the simplified models of power, load, DC/DC converters, and AC/DC converters considering droop control, a simplified model of a multi-terminal flexible DC distribution network is derived. Taking the impact of droop control into account, the simulation of DC distribution power flow under the different distribution of generation and load is done. Results show that the simplified model of DC distribution network with droop control can accurately and rapidly simulate the transient process and steady states of the testing network.

The control method of the conventional traction control system on split-μsurfaces improves vehicle acceleration performance, but influences its stability performance. To solve this problem, a hierarchical traction control system for ISG hybrid electric vehicles based on multi-objective dynamic coordination control (MHEVTCS) is proposed. In the upper level controller, a target driving torque calculating strategy based on dynamical sliding mode control is developed. In the lower level controller, such strategies as multi-objective dynamic coordination control strategy, brake torque control strategy based on an inverse model, target engine torque design strategy and torque dynamic coordinate control strategy are proposed. Detailed simulation and hardware-in-loop experiment results show that slipping wheels are controlled quickly, accurately and smoothly by MEHVTCS. MHEVTCS solves the problem of merely pursuing acceleration performance and neglecting stability performance of conventional traction control system.

This paper proposed an improved stator current control algorithm of Permanent Magnet Synchronous Motor (PMSM) for efficiency optimization. According to the formula of maximum input power of PMSM, relational expression between d, q axis current is established. Appling multiple input and multiple output system coordinated control theory to current control system; the improved stator current control algorithm is given. The simulation results have proven that the algorithm proposed in this paper can maximization output power in the case of minimum coordination deviation.

To solve the problems of task scheduling and coordination control presented by a multi-AGV system, the mixed regional control model for the production task has been advanced. The architecture of multi-AGV task assignment and scheduling mechanism has been proposed by combining the mixed regional control model for the production task and the neuro-endocrine coordination mechanism. Hormones for manufacturing cell are secreted by the machine tool according to the information in the production task, and the task can be allocated to the most suitable machine according to the hormone concentrations of the manufacturing cell. The AGV’s hormones are secreted according to the AGV’s operation state. The AGV with the largest hormone concentration will be chosen to execute the transportation task, thus shortening the overall run time of the system. A series of scheduling simulation experiments are performed for some specific examples to demonstrate the feasibility and efficacy of the proposed approach. The results show that tasks can be allocated according to the current status of a machine tool and tasks can be scheduled according to the current state of the AGV system to maximize the efficiency of the AGVs as well as that of the overall system.

International audience; We evaluated the role of visual and non-visual information in the control of smooth pursuit movements during tracking of a self-moved target. Previous works have shown that self-moved target tracking is characterised by shorter smooth pursuit latency and higher maximal velocity than eye-alone tracking. In fact, when a subject tracks a visual target controlled by his own arm, eye movement and arm movement are closely synchronised. In the present study, we showed that, in a condition where the direction of motion of a self-moved visual target was opposite to that of the arm (same amplitude, same velocity, but opposite direction of movement), the resulting smooth pursuit eye movements occurred with low latency, and continued for about 140 ms in the direction of the arm movement rather than in the direction of the actual visual target movement. After 140 ms, the eye movement direction reversed through a combination of smooth pursuit and saccades. Subsequently, while arm and visual target still moved in opposite directions, smooth pursuit occurred in pace with the visual target motion. Subjects were also submitted to a series of 60 tracking trials, for which the arm-to-target motion relationship was systematically reversed. Under these conditions subjects were able to initiate early smooth pursuit in the actual direction of the visual target. Overall, these results confirm that non-visual information produced by the arm motor system can trigger and control smooth pursuit. They also demonstrate the plasticity of the neuronal network handling eye-arm coordination control.

In this paper, a novel modelling and a hybrid formation control approach for the autonomous navigation for group of mobile robots in a specified formation is proposed. The hybrid approach consists of layered behaviour based control architecture with the behaviours classified into two levels. The supervisor level in the architecture handles the high-level missions such as formation and interobot communication, and the lower level deals with the dynamic control of the robots when navigating in the environment. The switching between the formation and the navigation is done based on the local information and the assigned role of the robots in the group. A modelling framework is also presented in this paper, where the individual behaviours of the hybrid formation control approach are modelled as temporal states and the performance of the approach is analysed through simulations. Experimental investigations have also been performed by using two commercially available robot research platforms. The results obtained are presented and discussed. Copyright � 2011 Inderscience Enterprises Ltd.

International audience; The aim of this study was to examine coordination control in eye and hand tracking of visual targets. We studied eye tracking of a self-moved target, and simultaneous eye and hand tracking of an external visual target moving horizontally on a screen. Predictive features of eye-hand coordination control were studied by introducing a delay (0 to 450 ms) between the Subject's (S's) hand motion and the motion of the hand-driven target on the screen. In self-moved target tracking with artificial delay, the eyes started to move in response to arm movement while the visual target was still motionless, that is before any retinal slip had been produced. The signal likely to trigger smooth pursuit in that condition must be derived from non-visual information. Candidates are efference copy and afferent signals from arm motion. When tracking an external target with the eyes and the hand, in a condition where a delay was introduced in the visual feedback loop of the hand, the Ss anticipated with the arm the movement of the target in order to compensate the delay. After a short tracking period, Ss were able to track with a low lag, or eventually to create a lead between the hand and the target. This was observed if the delay was less than 250-300 ms. For larger delays, the hand lagged the target by 250-300 ms. Ss did not completely compensate the delay and did not, on the average, correct for sudden changes in movement of the target (at the direction reversal of the trajectory). Conversely, in the whole range of studied delays (0-450 ms), the eyes were always in phase with the visual target (except during the first part of the first cycle of the movement, as seen previously). These findings are discussed in relation to a scheme in which both predictive (dynamic nature of the motion) and coordination (eye and hand movement system interactive signals) controls are included.

Rooftop Units (RTUs) have been widely applied in providing space heating and cooling for commercial buildings. In total, they serve over 60% of the commercial building floor space in the U.S. Even through the current control approaches of a RTU can maintain the zone temperature corresponding to a set point temperature, it performs inefficiently due to several factors such as limited sensing capability, non-coordinated local control, inherent oversizing effects and so on. In addition to unnecessary power consumptions, the current control and operation technology on RTUs also lead to the space humidity problem, equipment efficiency degradation, and premature failure. To solve aforementioned problems and enhance the overall system performance, this paper presents the development of a coordination control technique for improving the system operations of multiple RTUs used in light commercial buildings with an open space. In the control algorithm, simplified building models were developed to potentially estimate the instantaneous building load. Utilizing this model-based technique, sequence control strategy is designed to automatically select suitable mode operations of a RTU including economizing, heating, cooling and ventilation mode while synchronizing with the supply fan control and damper operations. Using a developed building simulation platform implemented on Matlab software, the developed coordination control is applied in reducing energy penalty caused by an inherent oversizing problem on multiple RTUs. With the findings, the control algorithm can be further used as a soft-repair for temporally fixing faulty operations and improper commissioning of multiple RTUs such as excessive or insufficient air flow, outdoor air leakage, stuck dampers and simultaneous heating and cooling (RTU fighting).