Search results for "Control system"
showing 10 items of 971 documents
Development of a Fractional PI controller in an FPGA environment for a Robust High-Performance PMSM Electrical Drive
2021
This paper proposes the application of a Fractional Order PI (FOPI) in the speed loop of a high performance PMSM drive to obtain both speed tracking and load rejection performance with a 1-DOF Proportional Integral (PI) controller and 2-DOF Integral Proportional (IP) controller. Hardware validation was implemented in Field Programmable Gate Array on the LabVIEW environment, based on the National Instruments System-on-Module sbRIO-9651 with Xilinx Zynq-7020. Simulation and experimental results are presented to comparing the performance of a PI, IP and FOPI controllers in the speed loop of a Field Oriented Control (FOC) of a Permanent Magnet Synchronous Motor (PMSM).
Robust, direct torque control of induction motor drives in application to industrial manipulator
2002
The paper analyses the application of three-phase small induction motors as the drives for industrial manipulator joints and their control related problems. By introducing a robust control to the whole systems in which the direct torque control is applied to driving motors, the solution presented is not only realistic but also yields high quality of trajectory tracking. The problem is widely illustrated by simulated results of manipulator's operation with that kind of drives including several control system options.
A Real-time Linux based controller for micro-vibration generating with voice coil actuator
2014
The micro-vibrations generated by mechanical systems onboard spacecraft can affect the performance of instruments with high pointing accuracy and stability. This paper provides a micro-vibration generating control system based on Real Time Application Interface (RTAI), a real time Linux extension, for ground tests purposes. The vibration generating control algorithm is filtered-X adaptive inverse control method. A voice coil actuator is used in the vibration generating experiments. The experiments show that the system can generate different frequency precision sine vibration whose error is less than 2 mg which is in environmental and electrical noise level.
One-sensor electronic olfactometer for rapid sorting of fresh fruit juices
2001
Abstract A low-cost electronic olfactometer was developed, based on virtual sensors array (an array of signals from a single metal oxide sensor) and on our proprietary semi-automated sampling system. This concept enables us to drastically improve the sensitivity and selectivity of the entire olfactometer to make it suited to food products analysis. Each step of the prototype was checked separately in earlier work, and finally the system performance was evaluated first on pure chemicals, and then at-line for grape juice during grape-harvesting in Champagne. It is shown that over a 3-week vintage period, the drift of the unique-sensor was quite low (absolute baseline value: avg., 2152; std., …
Critical analysis of thermal inertia approaches for surface soil water content retrieval
2013
The “thermal inertia” method to retrieve surface soil water content maps on bare or sparsely-vegetated soils is analysed. The study area is a small experimental watershed, where optical and thermal images (in day and night time) and in situ data were simultaneously acquired. The sensitivity of thermal inertia to the phase difference between incoming radiation and soil temperature is demonstrated. Thus, to obtain an accurate value of the phase difference, the temporal distance between thermographs using a three-temperature approach is evaluated. We highlight when a cosine correction of the temperature needs to be applied, depending on whether the thermal inertia formulation includes two gene…
Digital Holographic Microscopy: A New Imaging Technique to Quantitatively Explore Cell Dynamics with Nanometer Sensitivity
2014
In the first part of this chapter, we describe how the new concept of digital optics applied to the field of holographic microscopy has made it possible to quantitatively and accurately measure the phase retardation induced on the transmitted wavefront by the observed transparent specimen, allowing thus to develop a reliable and flexible digital holographic quantitative phase microscopy (DH-QPM). In the second part the most relevant DH-QPM applications in the field of cell biology are presented. Particularly, applications taking directly advantage of benefits provided by digital optics particularly off-line autofocusing and extended depth of focus, are outlined. Otherwise, special emphasis …
Reducing effects of aberration in 3D fluorescence imaging using wavefront coding with a radially symmetric phase mask.
2016
In this work, a wavefront encoded (WFE) imaging system built using a squared cubic phase mask, designed to reduce the sensitivity of the imaging system to spherical aberration, is investigated. The proposed system allows the use of a space-invariant image restoration algorithm, which uses a single PSF, to restore intensity distribution in images suffering aberration, such as sample–induced aberration in thick tissue. This provides a computational advantage over depth-variant image restoration algorithms developed previously to address this aberration. Simulated PSFs of the proposed system are shown to change up to 25% compared to the 0 µm depth PSF (quantified by the structural similarity i…
Towards a Dual-mode Adaptive MAC Protocol (DMA-MAC) for Feedback-based Networked Control Systems
2014
Abstract Automated control systems play an important part in many industrial domains and the medium used for communication between devices in these systems is in transition from wired to wireless for cost reasons. Control systems have strict requirements on delay, throughput, and reliability, that vary with time during operation. Addressing these requirements requires predictable and robust protocols to be employed, and they must be adaptive to the varying states of the controlled process. In this article, we propose a dual-mode adaptive medium access control protocol that caters for two main operation modes in control systems: the steady mode operation, and the transient mode operation. We…
Optimal passive-damping design using a decentralized velocity-feedback H-infinity approach
2012
In this work, a new strategy to design passive energy dissipation systems for vibration control of large structures is presented. The method is based on the equivalence between passive damping systems and fully decentralized static velocity-feedback controllers. This equivalence allows to take advantage of recent developments in static output-feedback control design to formulate the passive-damping design as a single optimization problem with Linear Matrix Inequality constraints. To illustrate the application of the proposed methodology, a passive damping system is designed for the seismic protection of a five-story building with excellent results. Peer Reviewed
Increasing Nanoparticles’ Refractive Index Sensitivity
2012
Since the plasmon resonance of nanoparticles depends on the refractive index of the immediate environment, these particles form the basis of many sensing schemes . The sensitivity of plasmon sensors for the detection of changes in the environment varies greatly and depends on the particle material and its morphology (size and shape). To further increase this sensitivity by chemical modifications was another goal of my work.