Validation of a Limited Information Shared Controller: A Comparative Study

This paper presents the validation and the comparative study of a shared control concept for a large vehicle manipulator (LVM). The state-of-the-art controlling a LVM is manual control: The operator controls the manipulator to carry out a specific task and keeps the vehicle on the road. Easing the work for the operator, an automatic lane-keeping of the vehicle can be taken into account: An automation of the vehicle which keeps it on its reference, but without taking into consideration of the manipulator\u27s specific task. However, the operator has his specific task with the manipulator, and therefore, such automation may not be satisfying. Therefore, this paper presents the validation and compares the Limited Information Shared Controller (LISC) proposed previously with the manual control mode. This step is crucial, showing the concept\u27s applicability and benefits compared to the state-of-the-art solution. Thus, the LISC is compared with a non-cooperative controller (NCC) and the manual mode on a real-time simulator with test subjects. It has a more realistic experimental setup than in other studies because there is no predefined manipulator reference. The study results indicate that the NCC can lead to undesired motions of the overall system because the test subjects cannot carry out their specific task. On the other hand, the proposed the LISC of the vehicle can reduce the working load while supporting the operator in carrying out the manipulator\u27s specific task

Explicit Port-Hamiltonian Representation of Feedthrough-Systems with Nonlinear Dissipation

In this technical note, we present an explicit port-Hamiltonian formulation of feedthrough systems subject to nonlinear energy-dissipating effects. To this end, we merge the Dirac structure which describes the system\u27s internal interconnection structure with the constitutive relations of energy-storing and energy-dissipating elements. The resulting port-Hamiltonian system (PHS) is proven to be passive and generalizes an existing nonlinear-dissipative port-Hamiltonian formulation from the literature by feedthrough

Guaranteed state estimation using a bundle of interval observers with adaptive gains applied to the induction machine

he scope of this paper is the design of an interval observer bundle for the guaranteed state estimation of an uncertain induction machine with linear, time-varying dynamics. These guarantees are of particular interest in the case of safety-critical systems. In many cases, interval observers provide large intervals for which the usability becomes impractical. Hence, based on a reduced-order hybrid interval observer structure, the guaranteed enclosure within intervals of the magnetizing current’s estimates is improved using a bundle of interval observers. One advantage of such an interval observer bundle is the possibility to reinitialize the interval observers at specified timesteps during runtime with smaller initial intervals, based on previously observed system states, resulting in decreasing interval widths. Thus, unstable observer dynamics are considered so as to take advantage of their transient behavior, whereby the overall stability of the interval estimation is maintained. An algorithm is presented to determine the parametrization of reduced-order interval observers. To this, an adaptive observer gain is introduced with which the system states are observed optimally by considering a minimal interval width at variable operating points. Furthermore, real-time capability and validation of the proposed methods are shown. The results are discussed with simulations as well as experimental data obtained with a test bench

The role of driver models in testing highly-automated driving: a survey [Die Rolle von Fahrermodellen für das Testen hoch-automatisierter Fahrfunktionen: Eine Übersicht]

Eine besondere Herausforderung bei der Entwicklung hoch-automatisierter Fahrfunktionen ist die Validierung dieser Systeme. Ein möglicher Ansatz, den Validierungsaufwand zu meistern, ist der Einsatz von Simulationen. Hierbei können Simulatoren für verschiedene Aspekte des Validierungs-Prozesses verwendet werden. Um verwendbare Ergebnisse zu erhalten, müssen die einzelnen Aspekte der Realität dabei durch entsprechende Modelle abgebildet werden. Basierend auf einer Analyse verschiedener Anwendungsfälle für Simulationen, werden in diesem Beitrag verschiedene Klassen von Modellen für das menschliche Fahrverhalten hinsichtlich ihrer An-wendbarkeit im Rahmen der simulativen Absicherung evaluiert

Shared Telemanipulation with VR controllers in an anti slosh scenario

Telemanipulation has become a promising technology that combines human intelligence with robotic capabilities to perform tasks remotely. However, it faces several challenges such as insufficient transparency, low immersion, and limited feedback to the human operator. Moreover, the high cost of haptic interfaces is a major limitation for the application of telemanipulation in various fields, including elder care, where our research is focused. To address these challenges, this paper proposes the usage of nonlinear model predictive control for telemanipulation using low-cost virtual reality controllers, including multiple control goals in the objective function. The framework utilizes models for human input prediction and taskrelated models of the robot and the environment. The proposed framework is validated on an UR5e robot arm in the scenario of handling liquid without spilling. Further extensions of the framework such as pouring assistance and collision avoidance can easily be included

Full- & Reduced-Order State-Space Modeling of Wind Turbine Systems with Permanent-Magnet Synchronous Generator

Wind energy is an integral part of nowadays energy supply and one of the fastest growing sources of electricity in the world today. Accurate models for wind energy conversion systems (WECSs) are of key interest for the analysis and control design of present and future energy systems. Existing control-oriented WECSs models are subject to unstructured simplifications, which have not been discussed in literature so far. Thus, this technical note presents are thorough derivation of a physical state-space model for permanent magnet synchronous generator WECSs. The physical model considers all dynamic effects that significantly influence the system's power output, including the switching of the power electronics. Alternatively, the model is formulated in the $(a,b,c)$- and $(d,q)$-reference frame. Secondly, a complete control and operation management system for the wind regimes II and III and the transition between the regimes is presented. The control takes practical effects such as input saturation and integral windup into account. Thirdly, by a structured model reduction procedure, two state-space models of WECS with reduced complexity are derived: a non-switching model and a non-switching reduced-order model. The validity of the models is illustrated and compared through a numerical simulation study.Comment: 23 pages, 11 figure

Optimal Scheduling of Combined Heat and Power Generation Units Using the Thermal Inertia of the Connected District Heating Grid as Energy Storage

A better integration across sectors is an essential element of 4th generation district heating and smart energy systems allowing to react to volatile renewable energy generation. This sector coupling enables to use more cost-efficient storage as storage prices differ for different forms of energy. Thermal energy for example can be stored in comparably cheap storage tanks. Besides such dedicated storage, the thermal inertia of a heating grid can be used as thermal storage as well. In this paper, a classic unit commitment optimization for scheduling of combined heat and power units not considering grid dynamics is extended to cover thermal dynamics of heating grids. First an outer approximation of the grid storage capabilities is developed. Second, a very efficient formulation for the storage dynamics of a heating grid is introduced and its capabilities are shown in a motivating case study. In this study additional savings of several thousand Euros per day are achieved using the thermal inertia of a heating grid as storage