Control of Selectable One-Way Clutch in GM Six-Speed Automatic Transmissions

2009 ◽  
Author(s):  
Chunhao J. Lee ◽  
Farzad Samie ◽  
Chi-Kuan Kao
Keyword(s):  
Engine Speed ◽  
Control Strategies ◽  
Transmission Efficiency ◽  
Reverse Direction ◽  
Passenger Vehicle ◽  
Shift Quality ◽  
Automatic Transmissions ◽  
The One ◽  
Free Spins ◽  
Force Pressure

Automatic transmissions use one-way clutches and regular clutches to control gear shifts. Regular one-way clutch locks in one direction and free spins (freewheeling) in the other direction and thus provides good shift quality. However, a clutch is needed if the freewheeling direction needs to be locked. The advantage of a selectable one-way clutch (SOWC) is that it can be designed to act like a regular one-way clutch, fully freewheels or locks in both directions. In the GM six-speed transmissions, there is one one-way clutch which is accompanied by a clutch CB1R to control between 1st gear and reverse direction. The study is to replace the one-way clutch and CB1R clutch with simply one selectable one-way clutch in GM 6-speed transmissions (1). This will eliminate one transmission clutch, reduce weight and cost, and improve transmission efficiency. The proposed design of transmission is applied to a GM SUV and a GM passenger vehicle. Different from a regular clutch, which can be applied with force/pressure from high slippage to lock-up between two elements, a selectable one-way clutch can only be applied to a lock-up position when the slippage between two elements is near zero speed. Also, an SOWC can only be released when there is no torque or force carried by the clutch while a regular clutch can be easily released by dropping the applied force/pressure. These requirements impose challenges of the control strategies of the SOWC, especially during the scenarios such as 2–1 engine idle downshift (engine braking) and 1–2 upshift (coasting). This paper reviews hardware design, vehicle implementation, and focuses on control of the selectable one-way clutch. Vehicle results demonstrate static and rolling garage shifts, 1–2 upshifts, 2–1 and coast downshifts. Also demonstrated is the successful application of engaging 1st gear engine braking with the SOWC. This control involves coordination between the engine speed and SOWC slip speed, and the apply/release of the device.

Engine Torque Non-Uniformity Evaluation Using Instantaneous Crankshaft Speed Signal

2001 ◽  
Author(s):  
Nicolò Cavina ◽  
Fabrizio Ponti
Keyword(s):  
Engine Speed ◽  
Combustion Engine ◽  
Control Strategies ◽  
Ignition Time ◽  
Operating Conditions ◽  
Injection System ◽  
Engine Torque ◽  
Production Variability ◽  
The One ◽  
Speed Fluctuations

Abstract The paper presents the development of a methodology for evaluating the torque non-uniformity between the various cylinders of an Internal Combustion Engine (ICE). This non-uniformity can be due, for example, to pathological operating conditions such as misfires or misfuels, as well as to other abnormal operating conditions. Between the nominal torque production and the one corresponding to the absence of combustion there exist, in fact, a series of possible intermediate conditions. Each of them corresponds to a value of produced torque that lies between the nominal value and the one corresponding to the lack of combustion (due for example to statistical dispersion in manufacturing or aging in the injection system). The diagnosis of this type of non-uniformity is a very important issue in today’s engine control strategies design. The use of the developed methodology should in fact allow the control strategy to adopt the appropriate interventions if the diagnosed non-uniformity is related to different behavior of the injectors. In order to evaluate this torque production variability between the various cylinders, information hidden in the instantaneous crankshaft speed fluctuations has been processed using a suitable methodology. The procedure has been validated running a supercharged 2.0 liters V6 engine, and a 1.2 liters L4 engine, in a test cell. During the tests, the in-cylinder pressure signal has been acquired together with the instantaneous engine speed, in order to determine a correlation between speed fluctuations and the indicated torque produced by each cylinder. The actual cylinder by cylinder torque non-uniformity can then be evaluated on-board by processing engine speed. The procedure is able to diagnose the absence of combustion (due for example to a misfire or a misfuel) as well as abnormal combustions that do not necessarily involve lack of combustion, with the accuracy needed for on-board use. Control interventions to injection and ignition time commands of one or more cylinders should in most cases be able to re-establish torque production uniformity.

Engine Torque Nonuniformity Evaluation Using Instantaneous Crankshaft Speed Signal

2003 ◽  
Vol 125 (4) ◽  
pp. 1050-1058 ◽  
Author(s):  
N. Cavina ◽  
F. Ponti
Keyword(s):  
Engine Speed ◽  
Combustion Engine ◽  
Control Strategies ◽  
Ignition Time ◽  
Operating Conditions ◽  
Injection System ◽  
Engine Torque ◽  
Production Variability ◽  
The One ◽  
Speed Fluctuations

The paper presents the development of a methodology for evaluating the torque nonuniformity between the various cylinders of an internal combustion engine (ICE). This nonuniformity can be due, for example, to pathological operating conditions such as misfires or misfuels, as well as to other abnormal operating conditions. Between the nominal torque production and the one corresponding to the absence of combustion there exist, in fact, a series of possible intermediate conditions. Each of them corresponds to a value of produced torque that lies between the nominal value and the one corresponding to the lack of combustion (due for example to statistical dispersion in manufacturing or aging in the injection system). The diagnosis of this type of nonuniformity is a very important issue in today’s engine control strategies design. The use of the developed methodology should in fact allow the control strategy to adopt the appropriate interventions if the diagnosed nonuniformity is related to different behavior of the injectors. In order to evaluate this torque production variability between the various cylinders, information hidden in the instantaneous crankshaft speed fluctuations has been processed using a suitable methodology. The procedure has been validated running a supercharged 2.0 liters V6 engine, and a 1.2 liters L4 engine, in a test cell. During the tests, the in-cylinder pressure signal has been acquired together with the instantaneous engine speed, in order to determine a correlation between speed fluctuations and the indicated torque produced by each cylinder. The actual cylinder-by-cylinder torque nonuniformity can then be evaluated on-board by processing engine speed. The procedure is able to diagnose the absence of combustion (due for example to a misfire or a misfuel) as well as abnormal combustions that do not necessarily involve lack of combustion, with, the accuracy needed for on-board use. Control interventions to injection and ignition time commands of one or more cylinders should, in most cases, be able to re-establish torque production uniformity.

Gear-Shift Control Strategy for a 6 Speed Wet-Type DCT

2013 ◽  
Vol 278-280 ◽  
pp. 1459-1465 ◽  
Author(s):  
Yan Qiong Teng ◽  
Xiao Feng Yin ◽  
De Wang Zhang
Keyword(s):  
Engine Speed ◽  
Ride Comfort ◽  
Unit Area ◽  
Control Strategies ◽  
Time Shift ◽  
Simulation Experiments ◽  
Gear Shift ◽  
Shift Quality ◽  
Shift Control

It is crucial to control the engagement of the in-coming clutch and the disengagement of the off-going clutch for the gear-shift process in order to improve the shift quality of dual clutch transmission (DCT). Aiming at the development of a 6 speed wet-type DCT, three evaluation indices of shift quality including shift time, shift jerk and friction work per unit area, were analyzed in detail. And the torque and the engine speed control strategies for the upshift and the downshift processes were discussed respectively through dividing the gear-shift process into 5 stages. The proposed strategies have been evaluated via simulation experiments of the upshift from gear position 1 to gear position 2 and downshift from gear position 2 to gear position 1, under wide-open throttle respectively. The results show that the proposed strategies can get short shift time and acceptable ride comfort, meanwhile prolong the service life of the friction elements of dual clutches.

A Spray-Droplet Model for Diesel Combustion

1969 ◽  
Vol 184 (10) ◽  
pp. 28-35 ◽  
Author(s):  
J. Shipinski ◽  
P. S. Myers ◽  
O. A. Uyehara
Keyword(s):  
Experimental Data ◽  
Diesel Engine ◽  
Heat Release ◽  
Engine Speed ◽  
Chamber Pressure ◽  
Gas Temperature ◽  
Single Droplet ◽  
Burning Rates ◽  
Burning Model ◽  
The One

A spray-burning model (based on single-droplet theory) for heat release in a diesel engine is presented. Comparison of computations using this model and experimental data from an operating diesel engine indicate that heat release rates are not adequately represented by single-droplet burning rates. A new concept is proposed, i.e. a burning coefficient for a fuel spray. Comparisons between computations and experimental data indicate that the numerical value of this coefficient is nearly independent of engine speed and combustion-chamber pressure. However, the instantaneous value of the spray burning coefficient is approximately proportional to the instantaneous mass-averaged cylinder gas temperature to the one-third power.

scholarly journals Dynamic Analysis and Control of an Automatic Transmission for Start-Stop Function and Efficiency Improvement

2015 ◽  
Vol 2015 ◽  
pp. 1-13
Author(s):  
Yang Liu ◽  
Shuhan Wang ◽  
Peng Dong ◽  
Xiangyang Xu
Keyword(s):  
Control Strategies ◽  
Automatic Transmission ◽  
Simulation Method ◽  
Transmission Efficiency ◽  
The Novel ◽  
Test Results ◽  
Test Environment ◽  
Pump System ◽  
Oil Pump ◽  
And Control

An electric oil pump (EOP) was integrated into the hydraulic system and an automatic transmission (AT) mechanical oil pump (MOP) was downsized. These processes were performed to combine a start-stop function with the AT and further improve the transmission efficiency. Furthermore, this study established a dynamics model of power loss and leakage of an 8-speed AT; a flow-based control algorithm of the EOP was then developed to realize the start-stop function and support the MOP to meet the flow requirement of the system. Based on a driving simulation method, sizes of the MOP and EOP that ensured optimal fuel economy were selected. A control strategy for the starting clutch was also developed to minimize the starting delay of the test vehicle. A test environment on a rig and prototype vehicle was established to verify the feasibility of the proposed control strategies. The test results indicated that the transmission functioned favorably with the novel two-pump system presented, and a quick and smooth starting performance was achieved when the engine was restarted. The findings in this study are extremely valuable for forward designs of an AT for realizing start-stop function and improving efficiency.

Control of flexible manipulators: A survey

Robotica ◽  
2004 ◽  
Vol 22 (5) ◽  
pp. 533-545 ◽  
Author(s):  
M. Benosman ◽  
G. Le Vey
Keyword(s):  
Linear Models ◽  
Control Strategies ◽  
Research Area ◽  
Future Research ◽  
Complex Nature ◽  
Open Problems ◽  
Complex Models ◽  
The Many ◽  
The One ◽  
Flexible Arms

A survey of the field of control for flexible multi-link robots is presented. This research area has drawn great attention during the last two decades, and seems to be somewhat less “attractive” now, due to the many satisfactory results already obtained, but also because of the complex nature of the remaining open problems. Thus it seems that the time has come to try to deliver a sort of “state of the art” on this subject, although an exhaustive one is out of scope here, because of the great amount of publications. Instead, we survey the most salient progresses – in our opinion – approximately during the last decade, that are representative of the essential different ideas in the field. We proceed along with the exposition of material coming from about 119 included references. We do not pretend to deeply present each of the methods quoted hereafter; however, our goal is to briefly introduce most of the existing methods and to refer the interested reader to more detailed presentations for each scheme. To begin with, a now well-established classification of the flexible arms control goals is given. It is followed by a presentation of different control strategies, indicating in each case whether the approach deals with the one-link case, which can be successfully treated via linear models, or with the multi-link case which necessitates nonlinear, more complex, models. Some possible issues for future research are given in conclusion.

Design, modeling, and analysis of wedge-based actuator with application to clutch-to-clutch shift

2017 ◽  
Vol 232 (9) ◽  
pp. 1149-1166
Author(s):  
Fengyu Liu ◽  
Li Chen ◽  
Jian Yao ◽  
Chunhao Lee ◽  
Chi-kuan Kao ◽  
...  
Keyword(s):  
Dynamic Models ◽  
Fast Response ◽  
Physical Structure ◽  
Modeling And Analysis ◽  
Shift Quality ◽  
Actuation System ◽  
Automatic Transmissions ◽  
Potential Alternative ◽  
Low Efficiency ◽  
Actuation Systems

Clutch-to-clutch shift technology is a key enabler for fast and smooth gear shift process for multi gear transmissions. However, conventional hydraulic actuation systems for clutches have drawbacks of low efficiency, oil leakage and inadequate robustness. Electromechanical devices offer potential alternative actuators. In this paper, a novel motor driven wedge-based clutch actuator, featuring self-reinforcement, is proposed. The design concept and physical structure are thoroughly described. Dynamic models for the actuation system and vehicle powertrain are validated by experiments. Upshift and downshift processes at different engine throttle openings, clutch clearances and friction coefficients are discussed. The results show that, the self-reinforcement ratio is tested as 9.6; at the same time, the shift quality is comparable to that of the conventional hydraulic actuated clutch in automatic transmissions in terms of the shift duration (about 1 s) and vehicle jerk (<10 m/s3). Taking advantage of fast response of the actuation DC motor, the wedge-based actuator is robust dealing with uncertain clutch clearance and friction coefficient. Therefore, the wedge-based clutch actuator has potential to provide acceptable performance for clutch-to-clutch shift.

scholarly journals Securitising Covid-19? The Politics of Global Health and the Limits of the Copenhagen School

2021 ◽  
Vol 43 (2) ◽  
pp. 235-257
Author(s):  
Daniel Edler Duarte ◽  
Marcelo M. Valença
Keyword(s):  
Global Health ◽  
Control Strategies ◽  
Security Studies ◽  
Health Security ◽  
Critical Security Studies ◽  
Scientific Controversies ◽  
Copenhagen School ◽  
State Surveillance ◽  
Critical Approaches ◽  
The One

Abstract The COVID-19 pandemic has sparked controversies over health security strategies adopted in different countries. The urge to curb the spread of the virus has supported policies to restrict mobility and to build up state surveillance, which might induce authoritarian forms of government. In this context, the Copenhagen School has offered an analytical repertoire that informs many analyses in the fields of critical security studies and global health. Accordingly, the securitisation of COVID-19 might be necessary to deal with the crisis, but it risks unfolding discriminatory practices and undemocratic regimes, with potentially enduring effects. In this article, we look into controversies over pandemic-control strategies to discuss the political and analytical limitations of securitisation theory. On the one hand, we demonstrate that the focus on moments of rupture and exception conceals security practices that unfold in ongoing institutional disputes and over the construction of legitimate knowledge about public health. On the other hand, we point out that securitisation theory hinders a genealogy of modern apparatuses of control and neglects violent forms of government which are manifested not in major disruptive acts, but in the everyday dynamics of unequal societies. We conclude by suggesting that an analysis of the bureaucratic disputes and scientific controversies that constitute health security knowledges and practices enables critical approaches to engage with the multiple – and, at times, mundane – processes in which (in)security is produced, circulated, and contested.

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