Early Model-Based Design and Verification of Automotive Control System Software Implementations

2014 ◽  
Vol 137 (2) ◽  
Author(s):  
Mahdi Shahbakhti ◽  
Mohammad Reza Amini ◽  
Jimmy Li ◽  
Satoshi Asami ◽  
J. Karl Hedrick
Keyword(s):  
Controller Design ◽  
Combustion Engine ◽  
Control Unit ◽  
Cold Start ◽  
Early Model ◽  
Automotive Control ◽  
Model Based ◽  
Numerical Noise ◽  
Software Implementations ◽  
Hc Emissions

Verification and validation (V&V) are essential stages in the design cycle of automotive controllers to remove the gap between the designed and implemented controller. In this paper, an early model-based methodology is proposed to reduce the V&V time and improve the robustness of the designed controllers. The application of the proposed methodology is demonstrated on a cold start emission control problem in a midsize passenger car. A nonlinear reduced order model-based controller based on singular perturbation approximation (SPA) is designed to reduce cold start hydrocarbon (HC) emissions from a spark ignition (SI) combustion engine. A model-based simulation platform is created to verify the controller robustness against sampling, quantization, and fixed-point arithmetic imprecision. In addition, the results from early model-based verification are used to identify and remove sources of errors causing propagation of numerical imprecision in the controller structure. Thus the structure of the controller is modified to avoid or to reduce the level of numerical noise in the controller design. The performance of the final modified controller is validated in real-time by testing the control algorithm on a real engine control unit. The validation results indicate the modified controller is 17–63% more robust to different implementation imprecision while it requires lower implementation cost. The proposed methodology from this paper is expected to reduce typical V&V efforts in the development of automotive controllers.

Engine thermomanagement with electrical components for fuel consumption reduction

2002 ◽  
Vol 3 (3) ◽  
pp. 157-170 ◽  
Author(s):  
E Cortona ◽  
C. H. Onder ◽  
L Guzzella
Keyword(s):  
Fuel Consumption ◽  
Cooling System ◽  
Combustion Engine ◽  
Cold Start ◽  
Operating Conditions ◽  
Coolant Temperature ◽  
Engine Operation ◽  
Cooling Systems ◽  
Engine Efficiency ◽  
Model Based

This paper proposes a solution for advanced temperature control of the relevant temperature of a combustion engine. It analyses the possibility of reducing vehicle fuel consumption by improving engine thermomanagement. In conventional applications, combustion engine cooling systems are designed to guarantee sufficient heat removal at full load. The cooling pump is belt-driven by the combustion engine crankshaft, resulting in a direct coupling of engine and cooling pump speeds. It is dimensioned such that it can guarantee adequate performance over the full engine speed range. This causes an excessive flow of cooling fluid at part-load conditions and at engine cold-start. This negatively affects the engine efficiency and, as a consequence, the overall fuel consumption. Moreover, state-of-the-art cooling systems allow the control of the coolant temperature only by expansion thermostats (solid-to-liquid phase wax actuators). The resulting coolant temperature does not permit engine efficiency to be optimized. In this paper, active control of the coolant flow as well as of the coolant temperature has been realized using an electrical cooling pump and an electrically driven valve which controls the flow distribution between the radiator and its bypass. For this purpose, a control-oriented model of the whole cooling system has been derived. Model-based feedforward and feedback controls of coolant temperature and flow have been designed and tested. With the additional actuators and the model-based control scheme, a good performance in terms of fast heat-up and small temperature overshoot has been achieved. The improvements in fuel consumption obtained with the proposed configuration have been verified on a dynamic testbench. Both engine cold-start under stationary engine operation and the European driving cycle MVEG-A with engine cold-start were tested. The fuel consumption reductions achieved during these tests vary between 2.8 and 4.5 per cent, depending on the engine operating conditions. Compared to vehicle mass reduction or internal engine improvements, engine thermomanagement is a simple, flexible and cost efficient solution for improving system performance, i.e. fuel consumption.

Model Based Design of Fuel Pump Control

2016 ◽  
Vol 821 ◽  
pp. 601-607 ◽  
Author(s):  
Ondrej Andrs ◽  
Jan Vetiska ◽  
Michal Holub ◽  
Jiri Kovar
Keyword(s):  
Combustion Chamber ◽  
Controller Design ◽  
Control Unit ◽  
Simulation Method ◽  
Variable Component ◽  
Control Effect ◽  
Fuel Pump ◽  
Pump Speed ◽  
Model Based ◽  
Speed Controller

This paper presents a co-simulation method to design of speed controller for turbojet fuel pump. Expected fuel pump is used for small turbine engine concept with reducer driven by free turbine. The amount of injected fuel into the combustion chamber is based on the speed of the fuel pump which is controlled by the engine control unit. The final flow of fuel into the combustion chamber is restricted by fuel bypass which constricts the return fuel according to pressure in the nozzles. This back fuel bypass has nonlinear and fixed characteristic determined by its structure. The only way how to control the amount of incoming fuel to the engine is the pump speed control. Effect of the bypass represents a variable component in the fuel pump load and from the view of the speed controller it is a disturbance variable. This paper describes the co-simulation model based on the use of MATLAB/Simulink and MSC Adams environment. This simulation uses interconnection of Simulink controller design and simplified model of the fuel pump dynamics in Adams (without hydraulic modelling).

Real-Time Hybrid Switching Control of Automotive Cold Start Hydrocarbon Emission

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Rasoul Salehi ◽  
Mahdi Shahbakhti ◽  
J. Karl Hedrick
Keyword(s):  
Real Time ◽  
Hybrid System ◽  
Catalytic Converter ◽  
Test Procedure ◽  
Control Unit ◽  
Cold Start ◽  
Emission Model ◽  
Hydrocarbon Emission ◽  
Hc Emissions ◽  
Hybrid Switching

Reduction of cold start hydrocarbon (HC) emissions requires a proper compromise between low engine-out HC emission and fast light-off of the three way catalytic converter (TWC). In this paper, a hybrid switching system is designed and optimized for reducing HC emissions of a mid-sized passenger car during the cold start phase of FTP-75 (Federal Test Procedure). This hybrid system has the benefit of increasing TWC temperature during the early stages of the driving cycle by switching between different operational modes. The switching times are optimized to reduce the cumulative tailpipe HC of an experimentally validated automotive emission model. The designed hybrid system is tested in real-time on a real engine control unit (ECU) in a model-in-the-loop structure. The results indicate the new hybrid controller reduces the HC emissions over 6.5% compared to nonswitching cold start controller designs.

scholarly journals Towards Automatic Model Based Controller Design for Reconfigurable Plants

2008 ◽  
Vol 41 (2) ◽  
pp. 342-346 ◽  
Author(s):  
Axel G. Michelsen ◽  
Roozbeh Izadi-Zamanabadi ◽  
Jakob Stoustrup
Keyword(s):  
Controller Design ◽  
Model Based

Application of a Phenomenological Model for the Engine-Out Emissions of Unburned Hydrocarbons in Driving Cycles

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Manuel Dorsch ◽  
Jens Neumann ◽  
Christian Hasse
Keyword(s):  
Phenomenological Model ◽  
Combustion Engine ◽  
Combustion Process ◽  
Formation Mechanisms ◽  
Emission Model ◽  
Engine Operation ◽  
Driving Cycles ◽  
Hc Emissions ◽  
Piston Crevice ◽  
Engine Map

In this work, the application of a phenomenological model to determine engine-out hydrocarbon (HC) emissions in driving cycles is presented. The calculation is coupled to a physical-based simulation environment consisting of interacting submodels of engine, vehicle, and engine control. As a novelty, this virtual calibration methodology can be applied to optimize the energy conversion inside a spark-ignited (SI) internal combustion engine at transient operation. Using detailed information about the combustion process, the main origins and formation mechanisms of unburned HCs like piston crevice, oil layer, and wall quenching are considered in the prediction, as well as the in-cylinder postoxidation. Several parameterization approaches, especially, of the oil layer mechanism are discussed. After calibrating the emission model to a steady-state engine map, the transient results are validated successfully against measurements of various driving cycles based on different calibration strategies of engine operation.

Unified multidisciplinary modeling and simulation analysis of internal power system

2021 ◽  
pp. 1-21
Author(s):  
Guojin Chen ◽  
Chang Chen ◽  
Yiming Yuan ◽  
Yishuai Yue
Keyword(s):  
Internal Combustion Engine ◽  
Modeling And Simulation ◽  
Physical System ◽  
Cooling System ◽  
Combustion Engine ◽  
Control Unit ◽  
Internal Combustion ◽  
Power Equipment ◽  
Supply Rate ◽  
Multidisciplinary Modeling

The internal combustion power equipment is a typical cyber-physical system (CPS). The traditional design method is to separate the information system from the physical system, and then to simulate and optimize separately every system. That can not achieve the best performance. Aiming at the internal combustion power equipment with multi-disciplinary deep integration, this paper establishes the multi-disciplinary model of the whole and key components based on Dymola software. There are mainly mechanical system, combustion system, cooling system, control system and other simulation models, including deceleration and fuel cut-off control unit modeling, start-stop control unit modeling and speed limit control unit modeling. The performance of each model is simulated and analyzed. The mathematical models of engine characteristic curve and fuel supply rate curve are established through experimental study. Finally, taking the simulation model of automobile power system as an example, the simulation calculation and experimental verification are carried out, and the relationship among fuel supply rate, torque, speed and valve of internal combustion engine is obtained, as well as the cooling capacity of the cooling system is studied. The experimental results show that the maximum error between the simulation speed curve and the actual speed curve is within ± 2 km/h. The research results of this paper can provide theoretical basis for multidisciplinary modeling and simulation of internal combustion power equipment, and also provide technical support for performance analysis of internal combustion engine.

Control-oriented modeling for the electrodynamic levitation with permanent magnet Halbach array

2021 ◽  
pp. 1-19
Author(s):  
Yongpan Hu ◽  
Zhiqiang Long ◽  
Yunsong Xu ◽  
Zhiqiang Wang
Keyword(s):  
Permanent Magnet ◽  
Controller Design ◽  
Levitation Force ◽  
Model Based ◽  
Halbach Array ◽  
Validation Experiment ◽  
Electromagnetic Models ◽  
Two Stages ◽  
Poor Stability ◽  
Maximum Minimum

Poor stability of the permanent magnet electrodynamic levitation hinders its application in the maglev field. Therefore, building a control-oriented model to improve its stability is most challenging. However, intractable electromagnetic models leading to an implicit relationship between levitation force and gap, yields a barrier for model-based controller design. To solve the above-mentioned problem, this paper develops a control-oriented model by two stages. Specifically, the first stage is to show an explicit formula of the levitation force with regard to the levitation gap by neglecting end effect; meanwhile the “maximum–minimum rectification” method is put forward to evaluating an accurate levitation force. The second stage is to bring forth the control-oriented model on basis of the estimated levitation force. Although the paper focus mainly on the development of the control-oriented model, an example of PD controller is provided to verify its validation. Experiment results demonstrate the estimated levitation force is highly consistent with the real one. Simulation results show that the control-oriented model is sufficiently reliable. The research bridges the gap between the physical model and the model-based controller for the electrodynamic levitation with permanent magnet Halbach array.

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