| 1. |
- Altaf, Faisal, 1982, et al.
(author)
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Evaluating the Potential for Cell Balancing Using a Cascaded Multi-Level Converter Using Convex Optimization
- 2012
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In: IFAC Proceedings Volumes (IFAC-PapersOnline). - 1474-6670. - 9783902823168 ; 3, s. 100-107
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Conference paper (peer-reviewed)abstract
- The modeling and design of an active battery cell balancing system using Multi- Level Converter (MLC) for EV/HEV/PHEV is studied. The MLC allows to independently switch ON/OFF each battery cell in a battery pack . This extra degree-of-freedom (DoF) can be exploited to optimally use each cell in order to balance among them the temperature and state-of- charge (SoC). This study has shown that the constrained convex optimization based control policy, exploiting the extra DoF of MLC, gives significant benefit in terms of reduction in temperature and SoC deviations, especially under parameter variations, compared to uniformly using all the cells. Thus, the MLC has promising potential to offer extra benefit of achieving cell balancing while being simultaneously used as a motor driver.
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| 2. |
- Altaf, Faisal, 1982, et al.
(author)
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Feasibility Issues of using Three-Phase Multilevel Converter based Cell Balancer in Battery Management System for xEVs
- 2013
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In: IFAC Proceedings Volumes (IFAC-PapersOnline). - 1474-6670. - 9783902823434 ; 46, s. 390-397
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Conference paper (peer-reviewed)abstract
- The use of a three-phase multilevel converter (MLC) as an integrated cell balancer and motor driver is investigated for three-phase AC applications in EVs/HEVs/PHEVs. The paper analyzed an issue of additional battery losses caused by the flow of reactive and/or harmonic power from each power cell of the three-phase MLC battery system. The paper also investigates the size of shunt capacitor required for compensation of the losses to acceptable level. This study concludes that the size of the required capacitor is too big for the vehicle application unless some other active compensation is used as well. Another practical way to employ the MLC as a cell balancer is to use it in a cascaded connection with the conventional three-phase two-level voltage source inverter however it may not be a cost-effective solution either due to high component count.
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| 3. |
- Andersson, Ingemar, 1969, et al.
(author)
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Detection of Combustion Properties in a Diesel Engine using Block Mounted Accelerometers
- 2014
-
In: IFAC Proceedings Volumes (IFAC-PapersOnline). - : Elsevier BV. - 1474-6670. - 9783902823625 ; 19, s. 11866-11871
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Conference paper (peer-reviewed)abstract
- Engine block mounted accelerometers was used for estimating combustion phasing parameters for a heavy duty diesel engine. Several sensor locations were evaluated for its sensitivity to combustion related vibrations and mechanical noise.One sensor-cylinder combination was selected for the evaluation of a simple algorithm to detect 10% and 50% burned mass fraction. The algorithm uses the accumulated accelerometer vibration energy as a base for extracting the 10% and 50% points respectively.The results show that the angular positions for 10% and 50% burned mass fraction can be estimated with precisions of 1.5 and 3 CAD respectively. It is also concluded that the early part of the accelerometer signal has a significant influence from a mechanical noise source related to the start of injection.
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| 4. |
- Anguelova, Milena, 1978, et al.
(author)
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An Efficient Method for Structural Identiability Analysis of Large Dynamic Systems
- 2012
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In: 16th IFAC Symposium on System Identification. - 1474-6670. - 9783902823069 ; 16:1, s. 941-946
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Conference paper (peer-reviewed)abstract
- Ordinary differential equation models often contain a large number of parameters that must be determined from measurements by parameter estimation. For a parameter estimation procedure to be successful, there must be a unique set of parameters that can have produced the measured data. This is not the case if a model is not structurally identifiable with the given set of outputs selected as measurements. We describe the implementation of a recent probabilistic semi-numerical method for testing local structural identifiability based on computing the rank of a numerically instantiated Jacobian matrix (observability/identifiability matrix). To obtain this, matrix parameters and initial conditions are specialized to random integer numbers, inputs are specialized to truncated random integer coefficient power series, and the corresponding output of the state space system is computed in terms of a truncated power series, which then is utilized to calculate the elements of a Jacobian matrix. To reduce the memory requirements and increase the speed of the computations all operations are done modulo a large prime number. The method has been extended to handle parametrized initial conditions and is demonstrated to be capable of handling systems in the order of a hundred state variables and equally many parameters on a standard desktop computer.
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| 5. |
- Anguelova, Milena, 1978, et al.
(author)
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When classical nonlinear time-delay state-space systems admit an input-output equation of neutral type
- 2010
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In: 9th IFAC Workshop on Time Delay Systems, TDS 2010, Prague, 7 - 9 June 2010. - 1474-6670. - 9783902661715 ; 9:PART 1, s. 200-205
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Conference paper (peer-reviewed)abstract
- This paper deals with nonlinear retarded time-delay systems that surprisingly admit an input-output representation of neutral type. It is shown that such an unexpected behaviour represents a strictly nonlinear phenomenon, for it cannot happen in the linear time-delay case where retarded systems always admit an input-output representation of retarded type. A necessary and sufficient condition under which the nonlinear systems admit a neutral input-output representation is given and strategies for finding an inputoutput representation of retarded type are briefly outlined. Some open problems that arise, like minimality and system transformations, are discussed as well.
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| 6. |
- Asbjörnsson, Gauti, 1985, et al.
(author)
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An On-line Training Simulator Built on Dynamic Simulations of Crushing Plants
- 2013
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In: IFAC Proceedings Volumes (IFAC-PapersOnline). - 1474-6670. - 9783902823427 ; 15:1, s. 218-223
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Conference paper (peer-reviewed)abstract
- Crushing plants are widely used around the world as a pre-processing step in the mineral and mining industries or as standalone processing plants for final products in the aggregates industry. Despite automation and different types of advanced model predictive control, many the processes are still managed by operators. The skill of the operators influences the process performance and thus production yield. Therefore, it is important to train the operators so they know how to behave in different situations and to make them able to operate the process in the best possible way. Different types of models for crushers and other production units have been developed during the years and the latest improvement is the addition of dynamic behavior which gives the crushing plants a time dependent behavior and performance. This can be used as a simulator for operators training. By connecting an Internet based Human Machine Interface (WebHMI) to a dynamic simulator with the models incorporated, an on-line training environment for operators can be achieved. In this paper, a dynamic crushing plant simulator implemented in MATLAB/SIMULINK has been connected to a WebHMI. The WebHMI is accessible via the Internet, thus creating a realistic control room for operators’ training. In the created training environment, the operators can be trained under realistic conditions. Simple training scenarios and how they could be simulated are discussed. Apart from the increased level of knowledge and experience among the operators, the time aspect is an important factor. While a real crushing plant is still being built, the operators to be can already be trained, saving a lot of the commissioning and ramp up time.
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| 7. |
- Barcellini, Alberto, et al.
(author)
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Integrating an Anti-Collision System Based on Laser Time-Of-Flight Sensor in an Industrial Robot Controller
- 2012
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In: 10th IFAC Symposium on Robot Control. - 1474-6670. - 9783902823113 ; , s. 664-669
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Conference paper (peer-reviewed)abstract
- Safe coexistence of industrial robots and human operators in the same workspace is one of the long standing goals of robotics research. One way to enforce safety is to endow the robotic system with additional sensors that can to some extent monitor the environment surrounding the robot and allow fast reaction to unexpected obstacles. This paper discusses the design of one such anti-collision system based on a laser Time-Of-Flight distance sensor. Integration of the external controller in the hardware and software architecture of a commercial industrial robot controller is discussed. Experimental results show fast response of the system to various obstacles
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| 8. |
- Berger, Christian, 1980, et al.
(author)
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An Interdisciplinary Perspective to the Design and Decision Support of Integral Safety Systems
- 2013
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In: IFAC Proceedings Volumes (IFAC-PapersOnline). - 1474-6670. ; 4:PART 1, s. 145-150
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Conference paper (peer-reviewed)abstract
- Next generation integral safety systems are expected to provide better protection against traffic accidents by interlinking sensors and actuators of active and passive safety. A series of advanced functions will be used to mitigate collisions and if they cannot be avoided they will at least reduce their severity. We explore the interplay between key technology areas towards a holistic approach in the design and decision support of integral safety systems. First, we refer to the main problems in the design of effective systems and the associated software engineering challenges. Recent advances in sensor data analytics are then explored and their integration with decision support for vehicle control is examined. Finally, we envision that rigorous design techniques based on models for human-machine interaction are essential for achieving adequate performance and robustness of integral safety systems.
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| 9. |
- Björkelund, Anders, et al.
(author)
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Knowledge and Skill Representations for Robotized Production
- 2011
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In: Proceedings of the 18th IFAC World Congress, 2011. - 1474-6670. - 9783902661937 ; , s. 8999-9004
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Conference paper (peer-reviewed)abstract
- Model-based systems in control are a means to utilize efficiently human knowledge and achieve high performance. While models consisting of formalized knowledge are used during the engineering step, running systems usually do not contain a high-level, symbolic representation of the control and most of its properties, typically named numerical parameters. On a system level and beyond the plant data, there is also a need to represent the meaning of the data such that deployment and fault analysis could be augmented with partly automated inference based on the semantics of the data. To that end, we extended the formalized knowledge traditionally used in control to include the control purpose, engineering assumption, quality, involved state machines, and so on. We then represented the control semantics in a format that allows an easier extraction of information using querying and reasoning. It aims at making knowledge in control engineering reusable so that it can be shipped together with the control systems. We implemented prototypes that include automatic conversion of plant data from AutomationML into RDF triples, as well as the automated extraction of control properties, the conversion of parameters, and their storage in the same triple store. Although these techniques are standard within the semantic web community, we believe that our robotic prototypes for semantic control represent a novel approach.
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| 10. |
- Bonafilia, Brian, et al.
(author)
-
Robust manual control of a manufacturing system using supervisory control theory
- 2014
-
In: IFAC Proceedings Volumes (IFAC-PapersOnline). - : Elsevier BV. - 1474-6670. - 9783902823625 ; 19, s. 748-753
-
Conference paper (peer-reviewed)abstract
- There are many situations where manual intervention in automated systems, such as flexible manufacturing systems, is inevitable. Commonly the control of a manufacturing system is implemented in terms of operations, and sequences thereof, and these operations can typically be run manually. However, running the operations in arbitrary order may lead to situations such as blocking or collisions, from which it its hard or even impossible to recover or to resume automatic execution. This paper describes an implementation of an operator interface for robust manual control of a manufacturing system, where the operator is aided not to manually drive the system into a state that breaches the system requirements. Hence, blocking and collisions are avoided, and automatic mode can always be resumed. From a model of the manufacturing system based on self-contained operations, each of which is identified in terms of events with preconditions, a supervisor is calculated by use of the Supervisory Control Theory framework. From this supervisor additional preconditions are extracted for each operation. The operations with the extended preconditions are then ported to an operator interface which allows manual control of the production cell by dynamically guiding the operator to only those operations for which the extended preconditions are satisfied.
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