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PI-Controller Design for Combustion-Timing Feedback, from n-Heptane to iso-Octane in Compression-Ignition Engines

Ingesson, Gabriel LU ; Yin, Lianhao LU ; Johansson, Rolf LU and Tunestål, Per LU (2017) In ASME Journal of Dynamic Systems, Measurement and Control
Abstract (Swedish)
The problem of designing robust and noise-insensitive PI controllers for pressure-sensor based combustion-timing control was studied through simulation. Different primary reference fuels (PRF) and operating conditions were studied. The simulations were done using a physics-based, control-oriented model with an empirical ignition-delay correlation. It was found that the controllable region, in-between the zero-gain region for early injection timings and the misfire region for late injection timings is strongly PRF dependent. As a result, it was necessary to adjust intake temperature to compensate for the difference in fuel reactivity prior to the controller design. With adjusted intake temperature, PRF dependent negative-temperature... (More)
The problem of designing robust and noise-insensitive PI controllers for pressure-sensor based combustion-timing control was studied through simulation. Different primary reference fuels (PRF) and operating conditions were studied. The simulations were done using a physics-based, control-oriented model with an empirical ignition-delay correlation. It was found that the controllable region, in-between the zero-gain region for early injection timings and the misfire region for late injection timings is strongly PRF dependent. As a result, it was necessary to adjust intake temperature to compensate for the difference in fuel reactivity prior to the controller design. With adjusted intake temperature, PRF dependent negative-temperature coefficient behavior gave different system characteristics for the different fuels. The PI-controller design was accomplished by solving the optimization problem of maximizing disturbance rejection and tracking performance subject to constraints on robustness and measurement-noise sensitivity. Optimal controller gains were found to be limited by the high system gain at late combustion timings and high-load conditions, furthermore, the measurement-noise sensitivity was found to be higher at the low-load operating points where the ignition delay is more sensitive to variations in load and intake-conditions. The controller-gain restrictions were found to vary for the different PRFs, the optimal gains for higher PRFs were lower due to a higher system gain, whereas the measurement-noise sensitivity was found to be higher for lower PRFs. (Less)
Abstract
The problem of designing robust and noise-insensitive PI controllers for pressure-sensor based combustion-timing control was studied through simulation. Different primary reference fuels (PRF) and operating conditions were studied. The simulations were done using a physics-based, control-oriented model with an empirical ignition-delay correlation. It was found that the controllable region, in-between the zero-gain region for early injection timings and the misfire region for late injection timings is strongly PRF dependent. As a result, it was necessary to adjust intake temperature to compensate for the difference in fuel reactivity prior to the controller design. With adjusted intake temperature, PRF dependent negative-temperature... (More)
The problem of designing robust and noise-insensitive PI controllers for pressure-sensor based combustion-timing control was studied through simulation. Different primary reference fuels (PRF) and operating conditions were studied. The simulations were done using a physics-based, control-oriented model with an empirical ignition-delay correlation. It was found that the controllable region, in-between the zero-gain region for early injection timings and the misfire region for late injection timings is strongly PRF dependent. As a result, it was necessary to adjust intake temperature to compensate for the difference in fuel reactivity prior to the controller design. With adjusted intake temperature, PRF dependent negative-temperature coefficient behavior gave different system characteristics for the different fuels. The PI-controller design was accomplished by solving the optimization problem of maximizing disturbance rejection and tracking performance subject to constraints on robustness and measurement-noise sensitivity. Optimal controller gains were found to be limited by the high system gain at late combustion timings and high-load conditions, furthermore, the measurement-noise sensitivity was found to be higher at the low-load operating points where the ignition delay is more sensitive to variations in load and intake-conditions. The controller-gain restrictions were found to vary for the different PRFs, the optimal gains for higher PRFs were lower due to a higher system gain, whereas the measurement-noise sensitivity was found to be higher for lower PRFs. (Less)
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ASME Journal of Dynamic Systems, Measurement and Control
external identifiers
  • scopus:85039560632
DOI
10.1115/1.4037834
language
English
LU publication?
yes
id
93ab7f6a-bf47-4a49-a2c5-ffb0bbe401fb
date added to LUP
2017-09-07 09:49:51
date last changed
2018-01-14 04:35:36
@article{93ab7f6a-bf47-4a49-a2c5-ffb0bbe401fb,
  abstract     = {The problem of designing robust and noise-insensitive PI controllers for pressure-sensor based combustion-timing control was studied through simulation. Different primary reference fuels (PRF) and operating conditions were studied. The simulations were done using a physics-based, control-oriented model with an empirical ignition-delay correlation. It was found that the controllable region, in-between the zero-gain region for early injection timings and the misfire region for late injection timings is strongly PRF dependent. As a result, it was necessary to adjust intake temperature to compensate for the difference in fuel reactivity prior to the controller design. With adjusted intake temperature, PRF dependent negative-temperature coefficient behavior gave different system characteristics for the different fuels. The PI-controller design was accomplished by solving the optimization problem of maximizing disturbance rejection and tracking performance subject to constraints on robustness and measurement-noise sensitivity. Optimal controller gains were found to be limited by the high system gain at late combustion timings and high-load conditions, furthermore, the measurement-noise sensitivity was found to be higher at the low-load operating points where the ignition delay is more sensitive to variations in load and intake-conditions. The controller-gain restrictions were found to vary for the different PRFs, the optimal gains for higher PRFs were lower due to a higher system gain, whereas the measurement-noise sensitivity was found to be higher for lower PRFs.},
  articleno    = {054502},
  author       = {Ingesson, Gabriel and Yin, Lianhao and Johansson, Rolf and Tunestål, Per},
  language     = {eng},
  month        = {09},
  series       = {ASME Journal of Dynamic Systems, Measurement and Control},
  title        = {PI-Controller Design for Combustion-Timing Feedback, from n-Heptane to iso-Octane in Compression-Ignition Engines},
  url          = {http://dx.doi.org/10.1115/1.4037834},
  year         = {2017},
}