A Mechatronic Cardiovascular Simulation System for Jugular Venous Echo-Doppler Training

Echo-doppler examination of the jugular vessel is a powerful tool for the early diagnosis of cardiovascular disorders that can be further related to central nervous system diseases. Unfortunately, the ultrasound technique is strongly operator-dependent, so the quality of the scan, the accuracy of the measurement, and therefore the rapidity and robustness of the diagnosis reflect the degree of training. The paper presents the development of a mechatronic simulation system for improving the skill of novice physicians in echo-doppler procedures. The patient is simulated by a silicone manikin whose materials are designed to have a realistic ultrasound response. Two tubes allow blood-mimicking fluid to flow inside the manikin, simulating the hemodynamics of the internal jugular vein. The mechatronic system is designed for controlling the flow waveform, to reproduce several clinical cases of interest for diagnosis. The experiments investigate the accuracy of the echo-doppler measurements performed on the proposed system by novice operators using a real ultrasound scanner

Discussion on: "State feedback fuzzy adaptive control for active shimmy damping"

The paper by Pouly et al. addresses modeling and control design for a classical physical system, an elastic rotating wheel with a vertical steering axis, which can be found in many vehicles characterized by critical safety issues, aircrafts and motorcycles above all. the aim of this discussion paper is to highlight the key points, in the paper by Pouly et al., that could be of interest for further investigation by the same authors and by other research groups working on similar topics. The rest of the paper presents the points of discussion following the sequential order in which fundamental steps of any control project are typically addressed: modeling, control design, realisation

Formal Methods for Manufacturing Systems Control Design

The aim of this thesis is to propose a formal methodology for the design and verification of industrial control systems, with particular regard to the domain of manufacturing machines. The methodology is driven by an approach derived from Software Engineering concepts and is supported by the definition of a set of specification languages, derived from the semi-formal notation of UML [UML01], that permit to describe all the aspects related to the design of a complete machine control system, both architectural and behavioral. In particular, the underlying approach of the development process is oriented to the modularization and encapsulation of control tasks, in order to obtain a system architecture composed of independent and reusable components, as is suggested by Object-Oriented design techniques. Because of the hybrid nature of Manufacturing Systems, the control system may be partitioned into logic control modules and continuous control modules. Ideally, the architecture specification language proposed in this thesis would permit to describe both kind of components, together with their interactions. However, since the proposed methodology is mainly oriented to the solution of logic control problems, which are those less supported by formal methods in the industrial practice, the behaviour specification language adopted, derived from Statecharts [Har87], is basically event-oriented, with extensions that permit the description of simple data-processing operations. With regard to behavioral design, the suggested approach is that of direct design, which means that operational specifications on the desired behaviour of the manufacturing machine (or its components) are explicitly mapped into an operational model for each control module defined in the architecture specification. Formal verification of the control system design model can be performed, by means of a translation into a formal language. In particular, the technique suggested is model checking, in order to prove desired properties expressed in a form of temporal logic. For example, a model checking tool that can serve the purpose is SMV [McM93], which uses the temporal logic dialect CTL [CA81]. The rest of the thesis is organized as follows: - Chapter 2 presents a review of the most important formalisms and techniques to model and control Discrete Event Systems, with particular regard to their applicability in the manufacturing industry. - Chapter 3 describes a number of Software Engineering techniques that have been successfully applied to the domain of Real-Time software design, even if they are principally supported by semiformal languages. In particular, the techniques adopting Statecharts for behavioral specification are described in depth and with emphasis on the different semantical interpretations. - Chapter 4 describes the design methodology for industrial control systems proposed by this thesis, including the underlying approach, the specification languages adopted and the relationships with the features of the application domain. - Chapter 5 presents the definition of formal procedures to verify the correctness of industrial control systems, designed and modeled with the methods proposed in Chapter 4, and briefly describes how the design models can be implemented on real controllers. - Chapter 6 summarizes the features of the proposed approach to Manufacturing Systems control design, that aim to introduce the use of formal methods in the industrial practice, and ends with proposals for future work. - The thesis ends with an illustrative example of control system design and verification, described in Appendix A, referred to a machine component quite common in the packaging industry

Complete and Consistent Payload Identification During Human-Robot Collaboration: A Safety-Oriented Procedure

The paper proposes a procedure to provide a complete and physically-consistent estimation of mass, center of mass and inertia tensor of the payload attached to the end-effector of an industrial manipulator equipped with a force/torque sensor. The procedure involves the generation of an artificial potential field that allows the proper excitation of the payload inertial parameters while avoiding static and dynamic obstacles, thus ensuring a safe and collaborative scenario. The adopted identification algorithm consists in the solution of a constrained non-linear optimization problem that guarantees the physical consistency of the inertial parameters. The proposed approach has been validated by simulating a typical collaborative workcell where a Franka-Emika Panda robot performs the procedure while avoiding dynamic obstacles

A brushless motor drive with sensorless control for commercial vehicle hydraulic pumps

The paper describes the electronic design of a brushless motor drive powering a hydraulic Motor-Pump-Unit (MPU) for automotive applications. The full MPU consists of a Permanent Magnet (PM) brushless motor, a three-phase MOSFET inverter with digital control and a gear pump for the hydraulic circuit. The MPU designed in this project is characterized by low voltage supply and high hydraulic output power, so that the choice of power electronic components have been particularly challenging, mainly because of conflicting requirements in terms of current rating and total cost. The experimental results obtained with a first MPU prototype demonstrate that the weak point of the complete mechatronic design is related to the volumetric efficiency of the gear pump, while the power converter and brushless motor assembly is characterized by an acceptable efficiency

Modelling and identification of residual generator functions for fault detection and isolation of a small aircraft

This paper addresses the design of a fault diagnosis scheme based on linear system frequency domain design. The main innovation of the method consists of integrating in one-step only, the derivation of an analytical model of residual generator functions for the diagnosis of the monitored process with the optimal design of the diagnostic system itself. Special attention will be given to the computation of residual generator functions in order to realise a complete fault diagnosis scheme when additive faults are present, as well as the optimisation of the performance that can be achieved under the presence of disturbance and unknown inputs. The combined modelling and identification approach for the computation of residual generators is exploited for fault detection and isolation of a small aircraft, characterised by a non-linear model, in the presence of disturbance. The results obtained in the simulation of the faulty behaviour of a Piper PA30 are finally reported

A Practical Approach to Object-Oriented Modeling of Logic Control Systems for Industrial Applications

The paper presents the results of an application of object-oriented modeling techniques to design manufacturing systems logic controllers. In particular, the semantical aspects of specification languages like UML and Statecharts, widely used in many software engineering methods, are analysed and discussed, with regard to their adequacy for the industrial domain and their verification with formal methods. The paper ends with the description of a practical case of study, which shows that the proposed design and verification techniques can be successfully adopted in a real industrial framework, given domain-specific adaptation of object-oriented modeling languages

Mechatronic design of a PM brushless motor-driven gear pump with sensorless control

The paper presents a review of all the design choices made during the realization of a novel hydraulic motor-pump-unit (MPU) for automotive applications, driven by a permanent magnet (PM) brushless motor with sensorless control. The MPU designed in this project is characterized by low voltage supply and high hydraulic output power, so that the choice of power electronic components have been particularly challenging, mainly because of conflicting requirements in terms of current rating and total cost. The experimental results obtained with a first MPU prototype demonstrates that the weak point of the complete mechatronic design is related to the volumetric efficiency of the gear pump, while the power converter and brushless motor assembly is characterized by a reasonable efficiency

PLC-based control of a robot manipulator with closed kinematic chain

The paper describes the design and implementation of a robot control system on a hardware platform based on a Programmable Logic Controller (PLC). The controlled robot is a 4 degrees of freedom (DOF) manipulator with a closed kinematic chain, designed for high-performance pick and place applications in a packaging workcell. The control software is fully developed on a commercial PLC system, using its standard programming tools and the multi-tasking features of its operating system. In particular, the paper analyse in detail the drawbacks and the advantages related to the choice of standard PLCs in this kind of applications, compared to the much common choice of specialized hardware or industrial personal computers, with particular emphasis on the computational performances obtained with the proposed control architecture