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In this paper, the authors report about recent achievement in distributed Micro Electro Mechanical Systems (MEMS) behavioral modeling, allowing both easy development and faster simulation for better integration of arrayed MEMS into systems. Design and simulation are produced by solver-based cost-effective solution using VHDL-AMS. A hierarchical circuit-level design methodology has been followed to model and simulate a MEMS array-based smart surface applied in air–fluid environment for 2D contactless micromanipulation. Using a V-shaped-based design approach, a top-down VHDL-AMS-based modeling has been first achieved with behavioral, structural behavioral, and component models, which include a MEMS-based pneumatic microactuator. Then, a modeling bottom-up approach has been developed to validate our design by comparing simulations and experiments of the distributed surface. Good agreements of resulting simulations have been successfully provided at all abstraction levels proving capability and facility of using VHDL-AMS for coupled distributed physical models.

This paper reports the design, fabrication and control of arrayed microelectromechanical systems (MEMS)-based actuators for distributed micromanipulation by generation and control of an air-flow force field. The authors present an original design of pneumatic microactuator, improving reliability and durability of a distributed planar micromanipulator described in the previous study. The fabrication process is based on silicon-on-insulator (SOI) wafer and HF (hydroflouric acid) vapor release, which also significantly increases the production yield of the 560 microactuator array device of 35times35 mm2. Minimization of the electrostatic actuation pull-in voltage through suspension shaping fabrication was also studied, and successfully validated for electrical efficiency improvement. A distributed control method to achieve good conveyance performance and reduce motion control instability was investigated. An emulation approach was chosen to validate a decentralized control strategy on the distributed active surface in order to conduct a proof-of-concept of a future smart structure, integrating sensors, intelligence, and microactuators. Thus, a centralized/decentralized control flow, inspired by autonomous mobile robot principles, was applied. It was modeled and implemented using C-programming language. Experimental and characterization results validate the control method for feedback micromanipulation with good velocity and load capacity performance

A technique for the self-alignment of components is applied to the assembly of a passive micro-valve which is to be used for safety purposes in a miniature fuel cell. The technique uses the capillary forces originating in the interactions of HMDS (Hexadimethyldisilazane) and the faces of the components to achieve their passive alignment. HMDS is chosen because it is a volatile, low surface tension and inert liquid. The originality of this method is that the liquid area is defined by the edges of the components. Compared to a traditional pick-and-place technique, it leads to a leakage rate more than five times smaller.

International audience; Distributed-air-jet MEMS-based systems have been proposed to manipulate small parts with high velocities and without any friction problems. The control of such distributed systems is very challenging and usual approaches for contact arrayed system don't produce satisfactory results. In this paper, we investigate reinforcement learning control approaches in order to position and convey an object. Reinforcement learning is a popular approach to find controllers that are tailored exactly to the system without any prior model. We show how to apply reinforcement learning in a decentralized perspective and in order to address the global-local trade-off. The simulation results demonstrate that the reinforcement learning method is a promising way to design control laws for such distributed systems.

International audience; In this paper, an efficient and reliable neural active power filter (APF) to estimate and compensate for harmonic distortions from an AC line is proposed. The proposed filter is completely based on Adaline neural networks which are organized in different independent blocks. We introduce a neural method based on Adalines for the online extraction of the voltage components to recover a balanced and equilibrated voltage system, and three different methods for harmonic filtering. These three methods efficiently separate the fundamental harmonic from the distortion harmonics of the measured currents. According to either the Instantaneous Power Theory or to the Fourier series analysis of the currents, each of these methods are based on a specific decomposition. The original decomposition of the currents or of the powers then allows defining the architecture and the inputs of Adaline neural networks. Different learning schemes are then used to control the inverter to inject elaborated reference currents in the power system. Results obtained by simulation and their real-time validation in experiments are presented to compare the compensation methods. By their learning capabilities, artificial neural networks are able to take into account time-varying parameters, and thus appreciably improve the performance of traditional compensating methods. The effectiveness of the algorithms is demonstrated in their application to harmonics compensation in power systems.

In this paper, a pneumatic conveyor and its control mode are proposed for tiny object manipulation. The conveyor consists of a 2D array of 560 air-nozzle actuators realized by the silicon MEMS technology. A distributed control method, based on local air-flow force application, has been developed and successfully validated. Experimental and characterization results are finally presented and analyzed.

In the present work, the authors were focused on control modes used in distributed microsystems. Especially, they studied distributed manipulation like motion active surface that have been an important topic in micro and nanofabrication field. After comparing advantages and drawbacks between centralized, decentralized and distributed control systems, they decided to apply the control mode to an airflow active surface based on pneumatic microactuator array, and fabricated by MEMS technology. The size of the device is about 35x35 mm 2 for 560 MEMS-based actuators and holes respectively at the front- and the back-side of the silicon substrate. In a first approach, and to overcome fabrication problems of the micro- smart system, combining electronic and electro mechanic elements, a co-design software/hardware solution was implemented. By this way, and using a digital image captured from a CCD camera, autonomy of the distributed microsystems could be developed. Afterward, a feedback control strategy was elaborated by applying principles of autonomous mobile robots that lend it to. A first prototype, validating all control mode principles was successfully implemented directly in software. Experiment results demonstrated advantages and good performances of the method.

In this paper, the authors proposed to study a model and a control strategy of a two-dimensional conveyance system based on the principles of the Autonomous Decentralized Microsystems (ADM). The microconveyance system is based on distributed cooperative MEMS actuators which can produce a force field onto the surface of the device to grip and move a micro-object. The modeling approach proposed here is based on a simple model of a microconveyance system which is represented by a 5 x 5 matrix of cells. Each cell is consisted of a microactuator, a microsensor, and a microprocessor to provide actuation, autonomy and decentralized intelligence to the cell. Thus, each cell is able to identify a micro-object crossing on it and to decide by oneself the appropriate control strategy to convey the micro-object to its destination target. The control strategy could be established through five simple decision rules that the cell itself has to respect at each calculate cycle time. Simulation and FPGA implementation results are given in the end of the paper in order to validate model and control approach of the microconveyance system.

In this paper, a design approach was proposed to define suitable structures of distributed controlled MEMS used in a pneumatic two-dimensional microconveyance system. After an introduction to distributed systems, a brief survey of their applications in the field of micromanipulation and prospect in industrial microfabrication was presented. Afterward, the authors introduced the notion of intelligent motion surface used in the field of pneumatic microconveyance. They analyzed suitable distributed structures based on elementary microconveyance, which are supposed to provide an appropriate air-flow force and overcome microfluidic problems. The first microconveyer prototype was fabricated by using bulk micromachining technique. It was developed to estimate MEMS density required to produce an elementary force to convey a micro-object. Then, a specific distributed structure was proposed to develop the pneumatic two-dimensional microconveyer device. The device size is 35 x 35 mm 2 for 560 MEMS-microvalves, controlled by distributed arrays and processed by a centralized intelligence via a microprocessor. From experimental conveyance results, we can conclude to the feasibility of the pneumatic microconveyance by distributed air-flow microactuators.

We developed a pneumatic conveyance system that consists of an array of micro air valves fabricated by MEMS technology. The array of 560 micro actuators successfully conveyed a small silicon chip, which was 3 mm/spl times/3 mm/spl times/100 /spl mu/m in size and 2 mg in weight. The chip was transferred to the force equilibrium point, which was generated by the arrayed actuators. In addition, we proposed a control method for the system; in this method, the equilibrium point is moved in order to transfer the object on it We also conveyed a small plastic chip, which was 5 mm /spl times/ 5 mm /spl times/ 1 mm in size and 38 mg in weight. In this case, efficient conveyance was achieved by detecting the object edge and applying tilted air jets to it. A full control of two-dimensional conveyance is under investigation. The control circuit chip was developed; the circuit is an array of cells that have optical sensors and processors. Distributed information processing by the cooperation of cells enabled detection of the shape of the conveyed object. Our future goal is to assemble the conveyance system with the circuit, and to realize the autonomous distributed micro conveyance system.

This paper deals with the main perturbations such as voltage harmonic pollution, voltage unbalance and voltage sag in electrical systems. The series active conditioner is able to compensate these voltages on the customer side or on the sub-transmission side, leaving the fundamental voltage in the load terminals. Two control approaches (PI, RST) have been studied to ensure the regulation of the output voltage filter. An advanced RST corrector has been developed. Two methods of the disturbance identification have been proposed and compared. In this paper, through the simulations made by SABER numerical code, an energetic study is presented when the compensation of one or a combination of these voltages is aimed at. A power rating comparison has also been performed between the case with PLL and without PLL.

The field oriented control of an induction motor is sensitive to machine parameters and some detuning is expected in most rotor flux oriented systems. Consequently, direct torque control has been introduced to reduce parameter sensitivity problems, which are negligible at high speed. The authors of this paper present principles and implementation, with a digital signal processor, of the control system. They propose solutions to correct integrators, which cause some drift and operation errors, and they estimate the possibilities of the proposal. They describe the methods used to obtain good performance, even in the low speed range, where the stator resistance influence becomes critical. >

An advanced common control method for shunt and series active conditioners, which compensate for the main types of disturbances in electrical power systems, is considered. If shunt and series actives conditioners are already well known as good compensation solutions for power quality improvement, it is also admitted that they generate some undesired components at switching frequency. To avoid these propagation problems, conditioner designers proposed a high-order output filter associated to a specific controller based on the RST control method. However, by applying this controller, it can be observed that a phase lag between the reference and the injected signal appears in the current and voltage control loop, which damages harmonic compensation. Therefore, a new RST controller is proposed, called RSTimp, to overcome the phase lag effects over the entire bandwidth for both active conditioners. The RSTimp proposed control method is validated through SABER simulations. These simulations show very good active conditioner performance in terms of rapidity, tracking and robustness for both current and voltage compensation.

The authors present a methodology for designing a CMOS very large scale integration (VLSI) controller for AC motor control. Step-by-step, top-down methodology based on hardware description languages (HDL) with mixed simulation was used to study digital adaptation and architecture implementation of the control algorithm. An application using the proposed methodology was studied: the direct torque control (DTC) of an AC motor. The DTC is described and VLSI examined. Analogue and digital models were used to describe the algorithm implementation, specific binary format and architecture. The register transfer level (RTL) model for the DTC controller was validated by mixed simulation. The ASIC layout was created using Austria Mikro System standard cell library for 0.8 μm CMOS. Finally, the authors compared this VLSI approach with software implementation and co-design methodology.