| 1. |
- Andersson, Ingemar, 1969, et al.
(författare)
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Detection of Combustion Properties in a Diesel Engine using Block Mounted Accelerometers
- 2014
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - : Elsevier BV. - 2405-8963 .- 1474-6670. - 9783902823625 ; 19, s. 11866-11871
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Konferensbidrag (refereegranskat)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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| 2. |
- Anguelova, Milena, 1978, et al.
(författare)
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An Efficient Method for Structural Identiability Analysis of Large Dynamic Systems
- 2012
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Ingår i: 16th IFAC Symposium on System Identification. - 1474-6670. - 9783902823069 ; 16:1, s. 941-946
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Konferensbidrag (refereegranskat)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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| 3. |
- Anguelova, Milena, 1978, et al.
(författare)
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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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Ingår i: 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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Konferensbidrag (refereegranskat)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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| 4. |
- Barcellini, Alberto, et al.
(författare)
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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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Ingår i: 10th IFAC Symposium on Robot Control. - 1474-6670. - 9783902823113 ; , s. 664-669
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Konferensbidrag (refereegranskat)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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| 5. |
- Björkelund, Anders, et al.
(författare)
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Knowledge and Skill Representations for Robotized Production
- 2011
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Ingår i: Proceedings of the 18th IFAC World Congress, 2011. - 1474-6670. - 9783902661937 ; , s. 8999-9004
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Konferensbidrag (refereegranskat)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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| 6. |
- Bonafilia, Brian, et al.
(författare)
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Robust manual control of a manufacturing system using supervisory control theory
- 2014
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - : Elsevier BV. - 2405-8963 .- 1474-6670. - 9783902823625 ; 19, s. 748-753
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Konferensbidrag (refereegranskat)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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| 7. |
- Bottegal, Giulio, et al.
(författare)
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Analysis and identification of complex stochastic systems admitting a flocking structure
- 2014
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - : Elsevier BV. - 1474-6670. - 9783902823625 ; , s. 2323-2328
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Konferensbidrag (refereegranskat)abstract
- We discuss a new modeling paradigm for large dimensional aggregates of stochastic systems by Generalized Factor Analysis (GFA) models. These models describe the data as the sum of a flocking plus an uncorrelated idiosyncratic component. The flocking component describes a sort of collective orderly motion which admits a much simpler mathematical description than the whole ensemble while the idiosyncratic component describes weakly correlated noise. The extraction of the dynamic flocking component is discussed for time-stationary systems.
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| 8. |
- Cescon, Marzia, et al.
(författare)
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On Data-driven Multistep Subspace-based Linear Predictors
- 2011
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Ingår i: 18th IFAC World Congress. - 1474-6670. - 9783902661937 ; 44:1, s. 11447-11452
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Konferensbidrag (refereegranskat)abstract
- The focus of this contribution is the estimation of multi-step-ahead linear multivariate predictors of the output making use of finite input-output data sequences. Different strategies will be presented, the common factor being the exploitations of geometric operations on appropriate subspaces spanned by the data. In order to test the capabilities of the proposed methods in predicting new data, a real-life example, namely, the case of blood glucose prediction in Type 1 Diabetes patients, is provided.
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| 9. |
- Cho, Jang Ho, et al.
(författare)
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On the H2 Decentralized Controller Synthesis for Delayed Bilateral Teleoperation Systems
- 2012
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Ingår i: 10th IFAC Symposium on Robot Control. - 1474-6670. - 9783902823113 ; , s. 393-398
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Konferensbidrag (refereegranskat)abstract
- Procedure for the synthesis of decentralized controllers for delayed bilateral teleoperation systems is proposed, based on the analytical solution of a global H2 optimization. Explicit state-space formulae for the optimal controller are presented. The controller possesses a neat structure, which preserves closed-loop stability regardless of the delay length. The behavior of the resulting teleoperation system is illustrated in simulations and verified by experiments.
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| 10. |
- Dabiri, Azita, 1984, et al.
(författare)
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Incident parameter scheduled freeway traffic control - A ramp meter approach
- 2014
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - : Elsevier BV. - 2405-8963 .- 1474-6670. - 9783902823625 ; 19, s. 11338-11343
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Konferensbidrag (refereegranskat)abstract
- A novel model based local ramp metering method is presented in the paper by means of incident scheduled freeway traffic control solution. First, second order macroscopic freeway model is used with appropriate incident parametrization to describe eventual and unattended traffic variation caused by off-nominal traffic conditions (e.g. accidents). These traffic anomalies are captured by adequate model parameters, i.e. incident parameters that can be on-line estimated. The paper is motivated by incident scheduled ramp-meter solution to encounter real-time incident parameter information. The main idea is to use local freeway control solution triggered by available incident parameter values. The proposed approach is local in the sense of considering only non-coordinated ramp meter solution, first. Furthermore, we apply locally optimal (linearized) control solution to satisfy throughput maximization objective. The formal controller synthesis involves parameters to correct, compensate the effect of incidents. The proposed method is evaluated and compared to other existing approach by using simulation environment.
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