Yves-Andre Chapuis

A Unified Artificial Neural Network Architecture for Active Power Filters

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

Design, fabrication, and control of MEMS-based actuator arrays for air-flow distributed micromanipulation

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

FPGA-Based Decentralized Control of Arrayed MEMS for Microrobotic Application

In this paper, the authors have developed and implemented a decentralized decision-making strategy using field-programmable gate array (FPGA) technology as a prototype for an integrated controller of a microelectromechanical systems (MEMS) array for air-flow planar micromanipulation. The MEMS array was proposed to be integrated in a hybrid multichip module containing the FPGA-based controller. Algorithms and architectures, used for the decentralized control implementation and the hardware resource optimization, are described. A charge-coupled device camera was used to make each MEMS like an autonomous system when the distributed MEMS chip was tested. Finally, under air-flow condition, the FPGA-based decentralized control system successfully performed an object manipulation.

Alternative approach in 3D MEMS-IC integration using fluidic self-assembly techniques

Nowadays, industries are investigating new, original and appropriate solutions to address challenges in 3D MEMS-IC large-scale integration. Self-assembly techniques are among those. We report on an alternative approach inspired from fluidic self-assembly and using the flip-chip method. Here, solder bumps are directly formed onto a MEMS chip using liquid solder solution in a bath. The self-alignment process is operated after surface treatment by plasma deposition to form high and low wettability selective patterns. Finally, MEMS and electronic chips are permanently bonded after low thermal heating without any pressure. Electrical contact is established and electromechanisms of the microsystems are proven. Compared to classic MEMS-IC flip-chip methods, this strategy presents many advantages: it is a low-cost and fast fabrication process requiring no specific equipment for deposition of solder bumps. Furthermore, it can be applied on different substrates and it does not require a specific pressure method during the bonding process. This strategy is also an appropriate fabrication method for large-scale MEMS integration where electronic connection density is high.

Quantization problem analysis on ASIC-based direct torque control of an induction machine

Latest developments in digital intelligent motion, as digital signal processors (DSPs), has strongly improved AC motor control performances. Application-specific-integrated circuit (ASIC) technology has changed the need for rapid process and low-cost processor. However, new technological problems appeared, requiring digital properties which need considering, such as quantization, sampling, word length and data types. The authors of this paper propose to study the quantization problems on ASIC-based direct torque control of an induction machine. They present a high level behavior model of the specific circuit and analyze the torque quantization errors. Finally, simulation results illustrate quantization influences on control performances with different data type solutions.

A MEMS array for pneumatic conveyor and its control based on distributed system

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.

MEMS conveyance system for pneumatic two-dimensional manipulation based on autonomous distributed systems

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.

Fluidic self-alignment applied to a micro-fluidic system

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.

Integrated control strategy for autonomous decentralized conveyance systems based on distributed MEMS arrays

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.

VHDL-AMS Modeling for Simulation of MEMS Array-Based Smart Surface Applied in Microfluid Air-Flow Environment

In this paper, the authors report about recent achievement in distributed MEMS behavioral modeling, allowing both easy development and faster simulation for better integration of arrayed MEMS into systems. Design and simulation are produced by PC-based cost-effective solution using VHDL-AMS. A hierarchical circuit-level design methodology has been followed to model and simulate in microfluidic environment a MEMS array-based smart surface applied in 2-D micromanipulation. First, a VHDL-AMS-based behavioral model has been achieved. Then, a lower abstraction level model based on structural behavioral model level has been developed and validated integrating a pneumatic micractuator component model. Experimental agreements of resulting simulations are successfully provided at both abstraction levels.