In-Cycle Knocking Detection and Feedback Control Based on In-Cylinder Pressure and Ion Current Signal in a GDI Engine

2016 ◽  
Author(s):  
Yintong Liu ◽  
Liguang Li ◽  
Haifeng Lu ◽  
Jun Deng ◽  
Zongjie Hu
Keyword(s):  
Feedback Control ◽  
Ion Current ◽  
Cylinder Pressure ◽  
Current Signal ◽  
Gdi Engine

Ion Current Detection During Cold Starting and Idling in Diesel Engines

2012 ◽  
Author(s):  
Sanket Gujarathi ◽  
Tamer Badawy ◽  
Naeim Henein
Keyword(s):  
Feedback Control ◽  
Signal Detection ◽  
Fuel Consumption ◽  
Diesel Engines ◽  
Ion Current ◽  
Current Signal ◽  
Gasoline Engines ◽  
Cold Starting ◽  
High Concentrations ◽  
Current Detection

Cold starting of diesel engines is characterized by inherent problems such as long cranking periods and combustion instability leading to an increase in fuel consumption and the emission of high concentrations of hydrocarbons which appear as white smoke. The ion current signal has been considered for the feedback control of both gasoline and diesel engines. However, the ion current signal produced from the combustion of the heterogeneous charge in diesel engines is weaker compared to that produced from the combustion of the homogeneous charge in gasoline engines. This presents a problem in the detection of the ion current signal in diesel engines, particularly during starting and idling operations. This paper investigates and addresses the ion current detection problems pertaining to cold starting and various idling speeds. Also, different approaches have been investigated to improve the signal detection under these conditions.

Analysis of ion current signal during negative valve overlap of HCCI combustion with high compression ratio

2020 ◽  
pp. 146808742097289
Author(s):  
Maximilian Wick ◽  
Denghao Zhu ◽  
Jun Deng ◽  
Liguang Li ◽  
Jakob Andert
Keyword(s):  
Combustion Process ◽  
Pressure Sensors ◽  
Ion Current ◽  
Cylinder Pressure ◽  
Combustion Control ◽  
Current Signal ◽  
Hcci Combustion ◽  
High Compression ◽  
Negative Valve Overlap ◽  
Valve Overlap

Homogenous charge compression ignition (HCCI) combustion is a low temperature combustion process which combines high combustion efficiency with ultra-low [Formula: see text] raw emissions. Steep increases of the in-cylinder pressure and unstable combustion sequences at the limits of the operating range can damage the engine and limit the use of HCCI to part load operation. This can be done using closed loop combustion control based on combustion parameters like the indicated mean effective pressure and the combustion phasing. Since in-cylinder pressure sensors are expensive components and therefore not suitable for series application, ion current sensors can be used as an additional source of information about the combustion. Combustion analysis using methods similar to those used in pressure based measurements can be implemented using an online analysis of the ion current signal. In this study, the ion current sensor will be examined for its suitability for combustion control under HCCI conditions with lean air/fuel ratios and high compression ratios. Research has found that the ion current signal is strongly depended on the boundary conditions. Especially the air/fuel ratio which plays an important role for signal strength during the combustion process. When using valve timings with negative valve overlap in combination with a fuel pre-injection, a further peak of the ion current signal close to the gas exchange top dead center can be found in addition to the one during combustion. At the same time, it is hard to extract information from the cylinder pressure signal during NVO. Under lean conditions this peak even exceeds the signal during combustion. This study analyzes the ion current signal during NVO and its potential to be used for future combustion control concepts. The ion current signal shows potential to stabilize HCCI combustion at high loads. However, the prediction of late combustion cycles is still challenging.

In-cycle combustion feedback control for abnormal combustion based on digital ion current signal

2017 ◽  
Vol 19 (2) ◽  
pp. 241-249 ◽  
Author(s):  
Yintong Liu ◽  
Jun Deng ◽  
Zongjie Hu ◽  
Liguang Li
Keyword(s):  
Feedback Control ◽  
Direct Injection ◽  
Gasoline Direct Injection ◽  
Ion Current ◽  
Processing Unit ◽  
Current Signal ◽  
Post Processing ◽  
Direct Injection Engine ◽  
Gasoline Direct Injection Engine

For better stability of ion current employed for in-cycle combustion diagnosis and feedback control, this research develops a digital post-processing unit for in-cylinder ion current signals. Based on the processed digital ion current signal, abnormal combustion in gasoline direct injection engine is successfully detected, and the in-cycle remedy feedback control is achieved as well. Both re-ignition and re-injection are utilized for misfiring remedy, and only re-injection is employed for knocking inhibition. The accuracy of misfiring diagnosis is achieved no less than 94%, and the re-injection combined with re-ignition operation is shown to be feasible for misfiring remedy as well. The accuracy of knocking diagnosis is around 85% (knocking rate = 20%). The re-injection under the pre-knocking condition is shown to be effective for knocking inhibition.

Knock and Pre-Ignition Detection Using Ion Current Signal on a Boosted Gasoline Engine

2017 ◽  
Author(s):  
Sunyu Tong ◽  
Zhaohui Yang ◽  
Xiaoyu He ◽  
Jun Deng ◽  
Zhijun Wu ◽  
...  
Keyword(s):  
Gasoline Engine ◽  
Ion Current ◽  
Current Signal

Master cylinder pressure reduction logic for cooperative work between electro-hydraulic brake system and anti-lock braking system based on speed servo system

2020 ◽  
Vol 234 (13) ◽  
pp. 3042-3055
Author(s):  
Lu Xiong ◽  
Wei Han ◽  
Zhuoping Yu ◽  
Jian Lin ◽  
Songyun Xu
Keyword(s):  
Feedback Control ◽  
Closed Loop ◽  
Servo System ◽  
Brake System ◽  
Extreme Condition ◽  
Pressure Reduction ◽  
Cylinder Pressure ◽  
Master Cylinder ◽  
Braking System ◽  
Hydraulic Brake

As one feasible solution of brake-by-wire systems, electro-hydraulic brake system has been made available into production recently. Electro-hydraulic brake system must work cooperatively with the hydraulic control unit of anti-lock braking system. Due to the mechanical configuration involving electric motor + reduction gear, the electro-hydraulic brake system could be stiffer in contrast to a conventional vacuum booster. That is to say, higher pressure peaks and pressure oscillation could occur during an active anti-lock braking system control. Actually, however, electro-hydraulic brake system and anti-lock braking system are produced by different suppliers considering brake systems already in production. Limited signals and operations of anti-lock braking system could be provided to the supplier of electro-hydraulic brake system. In this work, a master cylinder pressure reduction logic is designed based on speed servo system for active pressure modulation of electro-hydraulic brake system under the anti-lock braking system–triggered situation. The pressure reduction logic comprises of model-based friction compensation, feedforward and double closed-loop feedback control. The pressure closed-loop is designed as the outer loop, and the motor rotation speed closed-loop is drawn into the inner loop of feedback control. The effectiveness of the proposed controller is validated by vehicle experiment in typical braking situations. The results show that the controller remains stable against parameter uncertainties in extreme condition such as low temperature and mismatch of friction model. In contrast to the previous methods, the comparison results display the improved dynamic cooperative performance of electro-hydraulic brake system and anti-lock braking system and robustness.

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