scholarly journals Modeling, Analysis, and Optimal Design of the Automotive Transmission Ball Capsule System

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Xingyong Song ◽  
Mohd Azrin Mohd Zulkefli ◽  
Zongxuan Sun ◽  
Hsu-Chiang Miao
Keyword(s):  
Slope Angle ◽  
Fast Response ◽  
Optimal Shape ◽  
Effective Control ◽  
Shift Control ◽  
Automotive Transmission ◽  
Modeling Analysis ◽  
Clutch Engagement ◽  
Feedback Structure ◽  
Capsule Dynamics

Clutch shift control is critical for the performance and fuel economy of automotive transmissions, including both automatic and hybrid transmissions. Among all the factors that influence clutch shift control, clutch fill and clutch engagement are crucial to realize a fast and smooth clutch shift. When the clutch is not engaged, the fluid held by the centrifugal force inside of the clutch chamber, which introduces additional pressure that will affect the subsequent clutch fill and engagement processes, should be released. To realize this function, a ball capsule system is introduced and mounted on the clutch chamber. When the clutch chamber is ready to be filled for engagement, the ball capsule needs to close quickly and remain closed until the clutch is disengaged. It is also desirable to have an appropriate closing velocity for the ball capsule to minimize noise and wear. In this paper, the ball capsule dynamics is modeled, in which the derivation of the ball capsule throttling area is considered novel and critical because of its asymmetrical nature. Through this, the ball capsule’s intrinsic positive feedback structure is also revealed, which is considered to be the key to realize a fast response. Moreover, through the system dynamics analysis, the slope angle of the capsule is found to be an effective control parameter for system performance and robustness. To this end, the optimal shape of the capsule is designed using dynamic programming to achieve the desired performance.

A Novel Automotive Transmission Clutch Control Mechanism

2009 ◽  
Author(s):  
Mohd Azrin Mohd Zulkefli ◽  
Xingyong Song ◽  
Zongxuan Sun ◽  
Hsu-Chiang Miao
Keyword(s):  
Control Mechanism ◽  
Feedback Mechanism ◽  
Open Loop ◽  
Proper Function ◽  
Position Sensor ◽  
Internal Feedback ◽  
System A ◽  
Automotive Transmission ◽  
Feedback Structure ◽  
Clutch Control

Clutch fill control is critical for automotive transmission performance and fuel economy, including both automatic and hybrid transmissions. To ensure proper function of the transmission systems, it is important to have a precise and robust clutch fill process. Current clutch fill control is realized in an open loop fashion, due to the lack of a pressure or position sensor in the clutch chamber. To improve the accuracy and robustness of this system, a new clutch control mechanism is proposed, which includes an internal feedback structure without a pressure or position sensor. First, the design and working principles of the new mechanism are presented. Second, the advantages of the internal feedback mechanism are analyzed and shown to be superior to the traditional clutch fill mechanism. To this end, the dynamic model of the new mechanism is formulated. Through a series of simulations and case studies, the new clutch control mechanism is demonstrated to be effective, efficient, and robust for solving the clutch fill and engagement control problem.

scholarly journals Modeling, analysis, and optimal design of the automotive transmission ball capsule system

2009 ◽  
Author(s):  
Xingyong Song ◽  
Mohd Azrin Mohd Zulkefli ◽  
Zongxuan Sun ◽  
Hsu-Chiang Miao
Keyword(s):  
Optimal Design ◽  
Automotive Transmission ◽  
Modeling Analysis

Flight control system design with H ∞ loop-shaping approach through non-diagonal weights

2009 ◽  
Vol 113 (1145) ◽  
pp. 477-458 ◽  
Author(s):  
R. Panesi ◽  
G. Mengali
Keyword(s):  
Control System ◽  
System Design ◽  
Flight Control ◽  
Design Procedure ◽  
Fast Response ◽  
Effective Control ◽  
Control System Design ◽  
Simulink Model ◽  
Loop Shaping ◽  
Pointing Control

Abstract This paper deals with the design methodology of multi-variable flight control systems through a H ∞ loop-shaping technique. A new procedure for the design of non-diagonal pre-and post-compensators is described. In particular, important improvements over existing methods are introduced to both make the selection of weights easier and to contain the order of the resulting controller. The new procedure can be easily managed through suitable Matlab commands and functions, thus simplifying the whole algorithm implementation and providing an effective control system design with a minimum effort. Two typical design problems are addressed: a pitch pointing control system and a lateral controller for coordinated turns. In both cases, a good decoupling between existing channels is obtained by means of a non-diagonal pre-compensator which shapes the plant transfer function, and provides the desired response settling time. The design approach is particularly effective even for nominal plants with strong cross-coupling between channels. The design procedure is illustrated with the aid of a Matlab/Simulink model of a single seat fighter aircraft. We show that a trade-off between the conflicting requirements of fast response and moderate use of control surfaces can be easily managed by varying the constant terms of the diagonal post-compensator.

scholarly journals Delaying Selection for Fungicide Insensitivity by Mixing Fungicides at a Low and High Risk of Resistance Development: A Modeling Analysis

2011 ◽  
Vol 101 (10) ◽  
pp. 1224-1233 ◽  
Author(s):  
P. H. F. Hobbelen ◽  
N. D. Paveley ◽  
F. van den Bosch
Keyword(s):  
High Risk ◽  
Low Risk ◽  
Effective Control ◽  
Area Index ◽  
Resistance Risk ◽  
Quinone Outside Inhibitor ◽  
Modeling Analysis ◽  
Selection For ◽  
Fungicide Insensitivity ◽  
Effective Life

This study used mathematical modeling to predict whether mixtures of a high-resistance-risk and a low-risk fungicide delay selection for resistance against the high-risk fungicide. We used the winter wheat and Mycosphaerella graminicola host–pathogen system as an example, with a quinone outside inhibitor fungicide as the high-risk and chlorothalonil as the low-risk fungicide. The usefulness of the mixing strategy was measured as the “effective life”: the number of seasons that the disease-induced reduction of the integral of canopy green area index during the yield forming period could be kept <5%. We determined effective lives for strategies in which the dose rate (i) was constant for both the low-risk and high-risk fungicides, (ii) was constant for the low-risk fungicide but could increase for the high-risk fungicide, and (iii) was adjusted for both fungicides but their ratio in the mixture was fixed. The effective life was highest when applying the full label-recommended dose of the low-risk fungicide and adjusting the dose of the high-risk fungicide each season to the level required to maintain effective control. This strategy resulted in a predicted effective life of ≤12 years compared with 3 to 4 years when using the high risk fungicide alone.

Research on Integrated Control Method of Tiltrotor with Variable Rotor Speed Based on Two-Speed Gearbox

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Yong Wang ◽  
Qiangang Zheng ◽  
Haibo Zhang ◽  
Zhigui Xu
Keyword(s):  
Control Method ◽  
Integrated Control ◽  
Classical Mechanics ◽  
Fast Response ◽  
Rotor Speed ◽  
Component Level ◽  
Variable Model ◽  
Element Analysis ◽  
Shift Control ◽  
Turboshaft Engine

Abstract The process of rotor speed variation under tiltrotor cruise state has been studied, and the integrated variable speed control method of tiltrotor based on two-speed gearbox is proposed. Firstly, a nonlinear model predictive controller (NMPC) based on state variable model of the component-level model of the turboshaft engine is designed. Then based on the integrated engine model, the two-speed dual path tiltrotor driveline comprehensive simulation model was developed by utilizing gear kinematics theory, blade element analysis and the theory of classical mechanics. Finally, both a Parallel Shift Control (PSC) strategy and a Sequential Shift Control (SSC) strategy in tiltrotor cruise state were analyzed and compared with conventional PID controller. It is shown that the rotors’ speed can synchronously vary by 50 percent under the PSC strategy in tiltrotor cruise state. Meanwhile, disengaging the engine in turn by freewheel clutches can reduce the rotors’ speed from 190 rpm to 102.5 rpm along the specified path under the SSC strategy. The overshoot and droop amount of the power turbine speed can be reduced to less than 1.5 % with the steady error no more than 0.2 % through NMPC, which realizes the fast response control of the turboshaft engine.

Studies on the Fungal Pathogen of Dutch Elm Disease

1981 ◽  
Vol 39 ◽  
pp. 400-401
Author(s):  
H.M. Mazzone ◽  
G. Wray ◽  
R. Zerillo
Keyword(s):  
Fungal Pathogen ◽  
Fungal Growth ◽  
Polymyxin B ◽  
The United States ◽  
Dutch Elm Disease ◽  
Effective Control ◽  
Sabouraud Agar ◽  
Total Inhibition ◽  
Zones Of Inhibition ◽  
Control Plate

The fungal pathogen of the Dutch elm disease (DED), Ceratocystis ulmi (Buisman) C. Moreau, has eluded effective control since its introduction in the United States more than sixty years ago. Our studies on DED include establishing biological control agents against C. ulmi. In this report we describe the inhibitory action of the antibiotic polymyxin B on the causal agent of DED.In screening a number of antibiotics against C. ulmi, we observed that filter paper discs containing 300 units (U) of polymyxin B (Difco Laboratories) per disc, produced zones of inhibition to the fungus grown on potato dextrose agar or Sabouraud agar plates (100mm x 15mm), Fig. 1a. Total inhibition of fungal growth on a plate occurred when agar overlays containing fungus and antibiotic (polymyxin B sulfate, ICN Pharmaceuticals, Inc.) were poured on the underlying agar growth medium. The agar overlays consisted of the following: 4.5 ml of 0.7% agar, 0.5 ml of fungus (control plate); 4.0 ml of 0.7% agar, 0.5 ml of fungus, 0.5 ml of polymyxin B sulfate (77,700 U). Fig. 1, b and c, compares a control plate and polymyxin plate after seven days.

Ultrastructural analysis of “Sensory” surface nerve endings and “putative” neurotransmitter sites in Schistosoma mansoni Miracidia

1989 ◽  
Vol 47 ◽  
pp. 962-963
Author(s):  
Betty Ruth Jones ◽  
Steve Chi-Tang Pan
Keyword(s):  
Nervous System ◽  
Life Cycle ◽  
Schistosoma Mansoni ◽  
Snail Host ◽  
Complex Life Cycle ◽  
Rational Approach ◽  
Effective Control ◽  
The Social ◽  
Social And Economic Development ◽  
Basic Biology

INTRODUCTION: Schistosomiasis has been described as “one of the most devastating diseases of mankind, second only to malaria in its deleterious effects on the social and economic development of populations in many warm areas of the world.” The disease is worldwide and is probably spreading faster and becoming more intense than the overall research efforts designed to provide the basis for countering it. Moreover, there are indications that the development of water resources and the demands for increasing cultivation and food in developing countries may prevent adequate control of the disease and thus the number of infections are increasing.Our knowledge of the basic biology of the parasites causing the disease is far from adequate. Such knowledge is essential if we are to develop a rational approach to the effective control of human schistosomiasis. The miracidium is the first infective stage in the complex life cycle of schistosomes. The future of the entire life cycle depends on the capacity and ability of this organism to locate and enter a suitable snail host for further development, Little is known about the nervous system of the miracidium of Schistosoma mansoni and of other trematodes. Studies indicate that miracidia contain a well developed and complex nervous system that may aid the larvae in locating and entering a susceptible snail host (Wilson, 1970; Brooker, 1972; Chernin, 1974; Pan, 1980; Mehlhorn, 1988; and Jones, 1987-1988).

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