A Systematic Approach for Dynamic Analysis of Vehicles With Eight or More Speed Automatic Transmission

2014 ◽  
Vol 136 (5) ◽  
Author(s):  
Sangchul Lee ◽  
Yi Zhang ◽  
Dohoy Jung ◽  
Byungchan Lee
Keyword(s):  
Dynamic Behavior ◽  
Test Data ◽  
Performance Metrics ◽  
Automatic Transmission ◽  
Control Unit ◽  
Torque Converter ◽  
Fine Tuning ◽  
Transmission Control ◽  
Engine Torque ◽  
Shift Quality

In this study, a dynamic model of a vehicle with eight or more speed automatic transmission (A/T) has been developed for the analysis of shift quality and dynamic behavior of the vehicle during shift events. Subsystem models for engine, torque converter, automatic transmission, drivetrain, transmission control unit (TCU), and vehicle are developed and integrated with signal information interface. The subsystems included in the model were carefully selected to improve the accuracy of the model by comparing the simulation results with the test data. The systematic modeling approach based on matrix operation proposed in the study enables calibrating and fine-tuning the transmission control unit for shift quality in a virtual vehicle environment. The model presented in the study is validated with the vehicle test data and the comparison shows very good agreement. This paper presents a generalized modeling methodology for multiratio automatic transmissions that require both direct and indirect shifts. The model developed in the study provides a valuable analytical tool for the calibration and tuning of the transmission control unit by allowing quantitative analysis on the dynamic behavior and the performance metrics of an automatic transmission.

scholarly journals Tracking control and robustness study of shifting process

2018 ◽  
Vol 46 (2) ◽  
pp. 99-106
Author(s):  
Xin-xin Zhao ◽  
Chao Guan
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Tracking Control ◽  
Pid Controller ◽  
Automatic Transmission ◽  
Good Control ◽  
Simulation Software ◽  
Control Effect ◽  
Engine Torque ◽  
Shift Quality

Heavy dump vehicles are usually working with big load changes and bad work environment, thus change the friction performance of transmission clutches, as well as great affect the shift quality seriously, which influence the vehicle performance. Many researchers developed a lot to design a useful automatic transmission control system. Using PID tracking control and Monte Carlo method, the controller based on an dynamic model was set up to analyze the shifting process of automatic transmission and its robustness in this paper．The shift process was divided into four stages, low-gear phase, torque phase, inertia phase and high-gear phase. The model presents the process from the first gear to the second gear when the torque has big change．Since the jerk and the friction work of clutch are both related to the speed of clutch which was easier to control, it was chose as the target to control the oil pressure for satisfying the requirement of shift quality．The simulation software, Maplesim and Simulink, were used to build the vehicle model and shifting controller for simulation under different working conditions, and the maximum jerk was changed from 34 m/s3 to 12 m/s3 after the optimization. In this paper the Monte Carlo has been used to quantize and evaluate the robustness of the closed-loop system for the friction coefficients and output torque of turbine variation leading by the friction feature parameters and throttle angle changed. Monte Carlo method was used to analyze the effectiveness and robustness of PID controller, which proves that it has good control effect when the throttle is ongoing minor fluctuations. When the throttle is full opening, a quadratic optimal controller based on disturbance is designed by the method of multi-objective optimization. When it changes within 20 percent, PID controller was designed under the guidance of tracking thoughts. The results also show that the controller could still obtain better effect when the friction coefficient ranged from -40 % to 40 % as well as engine torque changed from -20 % to 20 %, which indicates the robustness of controller.

Research on an Approximate Model Based Virtual Calibration Method With DoE and Optimization Algorithm for Transmission Control Unit

2013 ◽  
Author(s):  
Guangqiang Wu ◽  
Lu Sun ◽  
Sheng Zhu ◽  
Kuankuan Zhang
Keyword(s):  
Subjective Experience ◽  
Automatic Transmission ◽  
Control Unit ◽  
Calibration Method ◽  
Approximate Model ◽  
Optimal Parameters ◽  
Latin Hypercube Design ◽  
Transmission Control ◽  
The Neural Network ◽  
Optimal Latin Hypercube Design

In order to solve the problems arising from the manual calibration method in the developing process of vehicle automatic transmission control unit (TCU), known as time-consuming, heavy workload, high cost and over-dependence on subjective experience, this article researches on a virtual calibration method based on an approximate model to obtain optimal parameters for TCU. The neural network approximate model is established from the test data chosen with the method of DoE (Design of Experiment). The virtual calibration method is then conducted through Optimal Latin Hypercube Design (OLHD) and multi-island genetic algorithm (MIGA) to search the optimal parameters. By comparing the new calibration method with original manual one on the condition of gear 1 up to gear 2, the result shows that the new method can increase the efficiency significantly.

Dynamics Equations of Planetary Gear Sets for Shift Quality by Lagrange Method

2008 ◽  
Author(s):  
Patinya Samanuhut ◽  
Atilla Dogan
Keyword(s):  
Equations Of Motion ◽  
Planetary Gear ◽  
Torque Converter ◽  
Vehicle Model ◽  
Lagrange Method ◽  
Engine Torque ◽  
Shift Quality ◽  
Planetary Gear Sets ◽  
And Shifts ◽  
Single Set

The equations of motion of planetary gear sets including pinion dynamics are derived using the Lagrange method. The Lagrange method provides a systematic procedure for derivation and yields a single set of equations that are valid for all gears and shifts for a given configuration. This procedure is applied to the coupled planetary gear set in GM Hydramatic 440 transmission. The planetary gear set equations along with a simplified engine, torque converter, friction elements and vehicle model are simulated for 2–3 and 3–4 shifts. The simulation results demonstrate that the equations derived for planetary gear sets can be used for studying shift quality.

A study of shift control using the clutch pressure pattern in automatic transmission

2003 ◽  
Vol 217 (4) ◽  
pp. 289-298 ◽  
Author(s):  
Woosung Han ◽  
Seung-Jong Yi
Keyword(s):  
Dynamic Models ◽  
Equations Of Motion ◽  
Automatic Transmission ◽  
Torque Converter ◽  
Optimum Pressure ◽  
Planetary Gears ◽  
Transient Characteristics ◽  
Engine Torque ◽  
Shift Control ◽  
Road Load

It is necessary to understand the overall system including engine, torque converter, multiplate clutch, band brake, one-way clutch, planetary gears, road load and tyre to analyse the performance of the vehicle powertrain. The performance of the powertrain can be analysed using dynamic models including transient characteristics and the equations of motion are derived from the dynamic models of the powertrain. In this study, the shift transient characteristics of the vehicle equipped with a Ravigneaux-type planetary gears automatic transmission has been investigated. A shift control using engine torque reduction and optimum pressure trajectory has also been investigated in order to enhance transient characteristics during shift.

Discuss BMW Automatic Transmission Work Principle and Fault Handling

2013 ◽  
Vol 273 ◽  
pp. 240-244
Author(s):  
Chao Chen
Keyword(s):  
Automatic Transmission ◽  
Torque Converter ◽  
Transmission System ◽  
Gear Transmission ◽  
Hydraulic Control ◽  
Transmission Control ◽  
Manual Gearbox ◽  
Fault Handling ◽  
Gear Transmission System ◽  
Fluid Coupling

The structure of the automatic transmission is slightly complicated than the manual gearbox, but its function has increased greatly. Classification, automatic transmission control of the gear transmission system can be divided into hydraulic control hydraulic automatic transmission and electronically controlled hydraulic automatic transmission, hydraulic transmission device can be divided into the structure of the fluid coupling and torque converter, combined with the above the structure and principle of a BMW to analyze automatic transmission failure and treatment.

Driving Intention Based Optimal Shift Control for Automatic Transmission

2014 ◽  
Vol 472 ◽  
pp. 36-43
Author(s):  
Sheng Zhu ◽  
Jun Hua Hu
Keyword(s):  
Automatic Transmission ◽  
Target Function ◽  
Control Unit ◽  
Gear Ratio ◽  
Torque Control ◽  
Shift Quality ◽  
Shift Control ◽  
Optimal Theory ◽  
Fuzzy Logic Method ◽  
Weighted Values

In general, discomfort and slipping loss cannot be avoided during gearshift due to discrete gear ratio. Therefore, improving shift quality has long been concerned in the developing process of automatic transmission. This paper presents the equivalent dynamic model of automatic transmission, based on which optimal theory is then applied to obtain ideal engaging/disengaging torque control. Driving intention is also taken into consideration in the optimal control by deciding the weighted values for slipping loss and jerk items in the target function with fuzzy logic method. The simulation results show a good reflection of driving intention and could be used to decide band/clutch apply pressure in the control unit developing process afterwards.

Torque Converter Stress Analysis by Transient FSI Technique

2011 ◽  
Author(s):  
Takeshi Yamaguchi ◽  
Akihiko Okumura
Keyword(s):  
Automatic Transmission ◽  
Deformation Mode ◽  
Torque Converter ◽  
Previous Method ◽  
Hydrodynamic Performance ◽  
Element Analysis ◽  
Engine Torque ◽  
The Core ◽  
Computational Fluid Dynamics Cfd ◽  
Blade Model

The performance of a torque converter has been one of the most important areas of improvement for an automatic-transmission equipped automobile. Improving the torque converter’s performance and efficiency is key to saving fuel consumption, which is an important consideration with recent environmental awareness. Moreover, improving the overall automobile performance has led to more compact and lightweight transmissions. With the growing space constraints, the evolution of the torque converter has been towards smaller and more elliptical shapes. Since the smaller blades within the torque converter still have to endure the same engine torque, more strength is required of each blade of the pump, the turbine and the stator. There has been much research carried out to predict hydrodynamic performance and to understand the flow field inside a torque converter either experimentally or analytically using Computational Fluid Dynamics (CFD). However, none of the research has focused on the strength of the torque converter components — the blade, the shell and the core. The previous method for evaluating the blade strength had been to apply a simple, centrifugal pressure load on the blade using Finite Element Analysis (FEA). This method is no longer adequate for predicting blade stress since the pressure distribution on the blade is now known from CFD results. In this work, the fluid-structure interaction (FSI) technique is used to determine the deformation, which is indicative of the stress level of the blade, the shell and the core. In addition, this research compares the computational results from a model containing all blades to a conventional model of a single blade with axial symmetry. Analysis of the model containing all blades shows a completely different deformation mode than the single-blade model, especially for the pump blade. The differing results suggest that using a single-blade model analysis is less accurate for examining the torque converter structure.

scholarly journals New polyp image classification technique using transfer learning of network-in-network structure in endoscopic images

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Young Jae Kim ◽  
Jang Pyo Bae ◽  
Jun-Won Chung ◽  
Dong Kyun Park ◽  
Kwang Gi Kim ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Transfer Learning ◽  
Test Data ◽  
State Of The Art ◽  
Early Stage ◽  
Statistical Significance ◽  
Recall Rate ◽  
Training Data ◽  
Fine Tuning ◽  
Accuracy Evaluation

AbstractWhile colorectal cancer is known to occur in the gastrointestinal tract. It is the third most common form of cancer of 27 major types of cancer in South Korea and worldwide. Colorectal polyps are known to increase the potential of developing colorectal cancer. Detected polyps need to be resected to reduce the risk of developing cancer. This research improved the performance of polyp classification through the fine-tuning of Network-in-Network (NIN) after applying a pre-trained model of the ImageNet database. Random shuffling is performed 20 times on 1000 colonoscopy images. Each set of data are divided into 800 images of training data and 200 images of test data. An accuracy evaluation is performed on 200 images of test data in 20 experiments. Three compared methods were constructed from AlexNet by transferring the weights trained by three different state-of-the-art databases. A normal AlexNet based method without transfer learning was also compared. The accuracy of the proposed method was higher in statistical significance than the accuracy of four other state-of-the-art methods, and showed an 18.9% improvement over the normal AlexNet based method. The area under the curve was approximately 0.930 ± 0.020, and the recall rate was 0.929 ± 0.029. An automatic algorithm can assist endoscopists in identifying polyps that are adenomatous by considering a high recall rate and accuracy. This system can enable the timely resection of polyps at an early stage.

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