Design methodology for smart actuator services for machine tool and machining control and monitoring

This paper presents a methodology to design the services of smart actuators for machine tools. The smart actuators aim at replacing the traditional drives (spindles and feed-drives) and enable to add data processing abilities to implement monitoring and control tasks. Their data processing abilities are also exploited in order to create a new decision level at the machine level. The aim of this decision level is to react to disturbances that the monitoring tasks detect. The cooperation between the computational objects (the smart spindle, the smart feed-drives and the CNC unit) enables to carry out functions for accommodating or adapting to the disturbances. This leads to the extension of the notion of smart actuator with the notion of agent. In order to implement the services of the smart drives, a general design is presented describing the services as well as the behavior of the smart drive according to the object oriented approach. Requirements about the CNC unit are detailed. Eventually, an implementation of the smart drive services that involves a virtual lathe and a virtual turning operation is described. This description is part of the design methodology. Experimental results obtained thanks to the virtual machine are then presented

A Neural Network Based Optimal Wide Area Control Scheme for a Power System

With deregulation of the power industry, many tie lines between control areas are driven to operate near their maximum capacity, especially those serving heavy load centers. Wide area control systems (WACSs) using wide-area or global signals can provide remote auxiliary control signals to local controllers such as automatic voltage regulators, power system stabilizers, etc to damp out inter-area oscillations. This paper presents the design and the DSP implementation of a nonlinear optimal wide area controller based on adaptive critic designs and neural networks for a power system on the real-time digital simulator (RTDS©). The performance of the WACS as a power system stability agent is studied using the Kundur\u27\u27s two area power system example. The WACS provides better damping of power system oscillations under small and large disturbances even with the inclusion of local power system stabilizers

Grid voltage control with wind turbine inverters by using grid impedance estimation

Currently, distributed generation (DG) units usually do not participate in the primary grid voltage control and inject power regardless. Only when the grid voltage level surpasses a certain threshold, these units shut down to avoid any overvoltage problems. In this paper, a method is developed to control the grid voltage by wind turbines. This way, the grid voltage level improves, and the wind turbine can still generate power under suboptimal grid voltage conditions. The effect on the grid voltage depends on the grid impedance ratio R/X. In this paper, the effectiveness of the grid voltage control is improved by estimating the grid impedance ratio in real-time to inject active and reactive power accordingly. The method is applied to wind turbines, but can be used for other DG units as well

Measurements, Models, Systems and Design

531 s.

Adaptive CPU Resource Management for Multicore Platforms

The topic of this thesis is adaptive CPU resource management for multicore platforms. The work was done as a part of the resource manager component of the adaptive resource management framework implemented in the European ACTORS project. The framework dynamically allocates CPU resources for the applications. The key element of the framework is the resource manager that combines feedforward and feedback algorithms together with reservation techniques. The reservation techniques are supported by a new Linux scheduler through hard constant bandwidth server reservations. The resource requirements of the applications are provided through service level tables. Dynamic bandwidth allocation is performed by the resource manager which adapts applications to changes in resource availability, and adapts the resource allocation to changes in application requirements. The dynamic bandwidth allocation allows to obtain real application models through the tuning and update of the initial service level table