| 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. |
- 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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| 3. |
- 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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| 4. |
- Furberg, Andreas, 1989, et al.
(författare)
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Optimal Selection of Driving Modes along a Commuter Route for a Plug-in Hybrid Electric Vehicle
- 2014
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - : Elsevier BV. - 2405-8963 .- 1474-6670. - 9783902823625 ; 19, s. 7867-7872
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Konferensbidrag (refereegranskat)abstract
- Many plug-in hybrid electric vehicles have predefined driving modes, e.g. electric drive and charge sustaining mode. For a driver it is not a trivial task to select a fuel optimal sequence of driving modes; a poor selection might even result in a severely degraded fuel economy. The purpose of this paper is therefore to investigate optimal mode selection along a well known commuter route. To obtain a predictable driving behaviour it is assumed that the driving mode is only allowed to change at a limited number of decision points, located where the driving conditions along the route changes. The optimal mode selection is computed using the well known Dynamic Programming algorithm. However, the results show that the optimal mode selection might be perceived as counterintuitive, as a mode is not necessarily optimal over a connected set with respect to battery state of charge, at a given decision point. To mitigate this type of behaviour a suboptimal algorithm is proposed, in which a mode is associated with one unique interval of state of charge at any decision point along the route. The results indicate that the proposed algorithm is only marginally suboptimal with respect to the optimal solution.
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| 5. |
- Grahn, Markus, 1978, et al.
(författare)
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A Transient Diesel EMS Strategy for Online Implementation
- 2014
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - : Elsevier BV. - 2405-8963 .- 1474-6670. - 9783902823625 ; 19, s. 11842-11847
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Konferensbidrag (refereegranskat)abstract
- A recently developed strategy for diesel engine management systems is modified to reduce the implementation complexity. The strategy calculates set points for engine management system controllable quantities with an aim to minimize fuel consumption for a given engine speed and requested torque profile, while keeping accumulated emissions below given limits. The strategy is based on the methodology for steady-state engine operation, but extended to handle transient effects in the engine caused by dynamics in the air system. The strategy leads to the parametrization of mappings with two, three and four input dimensions respectively. In this paper, a modification of the strategy is proposed such that the memory demanding multidimensional mappings can be approximated in an engine management system using only two-dimensional grid maps. The modified strategy has been evaluated using a complete diesel engine vehicle system model simulating the NEDC driving cycle. The performance of the modified strategy has been compared with the original performance of the strategy. It is demonstrated that the modification of the strategy has very little impact on resulting performance of a vehicle but requires considerably less memory for implementation.
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| 6. |
- Kianfar, Roozbeh, 1984, et al.
(författare)
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A Control Matching-based Predictive Approach to String Stable Vehicle Platooning
- 2014
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - : Elsevier BV. - 2405-8963 .- 1474-6670. - 9783902823625 ; 19, s. 10700-10705
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Konferensbidrag (refereegranskat)abstract
- A predictive control strategy for vehicle platoons is presented in this paper,accommodating both string stability and constraints (e.g., physical and safety) satisfaction.In the proposed design procedure, the two objectives are achieved by matching a ModelPredictive Controller (MPC), enforcing constraints satisfaction, with a linear controller designedto guarantee string stability. The proposed approach neatly combines the straightforward designof a string stable controller in the frequency domain, where a considerable number of approacheshave been proposed in literature, with the capability of a MPC-based controller of enforcingstate and input constraints.A controller obtained with the proposed design procedure is validated in simulations, showinghow string stability and constraints satisfaction can be simultaneously achieved with a singlecontroller. The operating region that the MPC controller is string stable is characterized by theinterior of feasible set of the MPC controller.
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| 7. |
- Lei, Z., et al.
(författare)
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Residual capacity estimation for ultracapacitors in electric vehicles using artificial neural network
- 2014
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - : Elsevier BV. - 2405-8963 .- 1474-6670. - 9783902823625 ; 19, s. 3899-3904
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Konferensbidrag (refereegranskat)abstract
- The energy storage system (ESS) plays a significant role in fulfilling the driving performance requirements and ensuring operational safety in an electric vehicle. Ultracapacitors (UCs) are being actively studied and used in parallel with batteries or fuel cells forming hybrid energy storage systems in electric vehicles. They show excellent potential in terms of the sourcing and sinking of power, particularly for the peak-power demand encountered in aggressive regenerative braking. Since there are an increasing number of ultracapacitor applications, which now includes commercial automotive applications, establishing a good model to represent their dynamics, especially the residual capacity estimation (RCE), is vital; but this is challenging. This paper presents a residual capacity estimation model which is based on an artificial neural network (ANN). This takes both charging and discharging current and temperature into consideration. The proposed ANN model comprises of three inputs and one output: the inputs are temperature, current and voltage, and the output is the residual charge. The model is trained and validated by feeding a test database which is extracted from experimental testing of ultracapacitors at different currents and temperatures on a well-established test rig. The training data should span the whole prediction scope, therefore the test currents and temperatures both vary over a wide range and cover all the possible operational conditions of the on-board ultracapacitors. The Back-Propagation (BP) algorithm, together with an early stopping strategy, is adopted to train the proposed ANN model to assure adequately accurate prediction while avoiding overfitting risks. The model performance is validated with experimental results over a set of test data randomly selected.
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| 8. |
- Murgovski, Nikolce, 1980, et al.
(författare)
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Computationally efficient energy management of a planetary gear hybrid electric vehicle
- 2014
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - : Elsevier BV. - 2405-8963 .- 1474-6670. - 9783902823625 ; 19
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Konferensbidrag (refereegranskat)abstract
- We present a method for obtaining a computationally efficient, sub-optimal energy management of an electrified vehicle containing a planetary gear set. We first reformulate the optimization problem to become separable in space (optimization variables). The problem is then decomposed into two optimization problems. The first is a static problem that looks for the optimal engine speed that maximizes efficiency of a compound unit, resembling an engine-generator unit combining the planetary gear and kinetic energy converters connected to it. The second is a dynamic optimization problem deciding the optimal power split between an electric buffer and the compound unit. By approximating the losses of the compound unit as convex, second order polynomial in generated power, we are able to solve the power split problem in less than 2 seconds, when the engine on/off sequence is known in advance. By comparing results with dynamic programming, we observed an approximation error of less than 0.2%.
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| 9. |
- Nilsson, Julia, 1986, et al.
(författare)
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Manoeuvre generation and control for automated highway driving
- 2014
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - : Elsevier BV. - 2405-8963 .- 1474-6670. - 9783902823625 ; 19, s. 6301-6306
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Konferensbidrag (refereegranskat)abstract
- A hierarchical, two-level architecture for manoeuvre generation and vehicle control for automated highway driving is presented. The high-level planner computes a manoeuvre in terms of a (X, Y)-trajectory as well as a longitudinal velocity profile, utilizing a simplified point-mass model and linear collision avoidance constraints. The low-level controller utilizes a non-linear vehicle model in order to compute the vehicle control inputs required to execute the planned manoeuvre. Both the high-level planner and low-level controller are formulated based on the model predictive control methodology. Simulation results demonstrates the ability of the high-level planner to compute appropriate, traffic-dependent manoeuvres, that can be tracked by the low-level controller in real-time.
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| 10. |
- Nilsson, Jonas, 1979, et al.
(författare)
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Verification of Collision Avoidance Systems using Reachability Analysis
- 2014
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - : Elsevier BV. - 2405-8963 .- 1474-6670. - 9783902823625 ; 19, s. 10676-10681
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Konferensbidrag (refereegranskat)abstract
- This paper presents a method for formal verification of automotive collision avoidance systems. Using viability theory and reachability analysis, we define when the system should intervene, i.e. the unsafe set, and when the system should not intervene, i.e. the safe set. Given these sets, we formulate the problem of verifying that a given system does not make incorrect decisions as an optimization problem. The method is demonstrated on a collision avoidance system example and, given the models used and absence of measurements errors, we show that the system does not make incorrect decisions. Furthermore, we describe and demonstrate how to evaluate the robustness to measurement errors, using the proposed framework.
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