AUTOMATIC TRANSMISSIONS. COMPLEX OF ALGORITHMS OF “CLUTCH-TO-CLUTCH SHIFTS” TECHNOLOGY: ANALYSIS OF ARCHITECTURE, GENERALIZED STRUCTURE, DEVELOPMENT. PART 2

The article continues the series of the author publications, which considers the main provisions of the “Clutch-to-Clutch Shifts” (CTC) technology — technology for automatic controlling the switching of automatic transmission (AT) stages, used in the global mass production of vehicles, hybrid and battery electric vehicles. It provides high-quality shifts, brought to the level of continuously variable transmissions. Development of power units in recent years has led to a rapid increase in the number of AT stages, which is accompanied by a complication of kinematic schemes, designs, control algorithms and, in general, an increase in the role of mechatronic control systems (MCS) in ensuring their high technical level. Effectiveness of the CTC technology depends on the perfection of the algorithms used. But their composition is not specified, which, with a large amount of information, makes it difficult for potential users to navigate in this set. In this paper, we propose (for the first time in the Russian language) the generalized structure of a set of standard algorithms necessary for the implementation of this technology in the AT MCS, which is developed on the basis of their selection from a pre-formed database of patents and publications on the theory and technology of AT control, following classification and grouping by functional purpose. For each item of the structure, there are links to patents with matching names. Detailed descriptions of several typical CTC algorithms in the AT MCS of General Motors patents are given.

Tool Evaluation & Design Analysis for Parking Pawl Mechanism

Automatic Transmissions in vehicles are becoming the norm today and with the need to reduce fuel consumption, electric vehicles are increasing in number too. As the vehicles get smarter, transmissions have also felt the need to adapt so as to cope with the demands of the 21st century. Apart from providing the user with different driving modes, vehicles with an Automatic Transmission and electric vehicles have a device called a Park Lock. Park Lock Mechanisms are devices that are fitted to vehicles with an automatic transmission or electric vehicles which can secure the vehicle mechanically in addition to the parking brakes to prevent an unintended movement of the vehicle when the vehicle is brought to a stop. This system can face various kinds of loads coming from the transmission or from the wheel side. So, it is necessary to design a system which can withstand against it. Today, when a park lock mechanism is designed, it is designed in a way that it not only fits one vehicle variant but many variants (these variants can include either front wheel drive, rear wheel drive, vehicles with varying final gear to park lock gear ratios etc). Therefore, one Park Lock Mechanism needs to satisfy various conditions and requirements. Carrying out calculations with different notations for each variant becomes a cumbersome procedure, therefore it is prudent to have one common platform which can do the calculation in the early phases of design. In this paper, a closed form calculationsbased Excel VBA tool can able to estimate the loads coming on to the Park lock mechanism by doing some background calculation is presented followed by the simulation performed using Multi Body Dynamics software (‘ADAMS’). Results from MBD tool and a 1D tool are corelated to the test data to gain some confidence on the tool which created in Excel VBA. Keywords: Park Lock Mechanism, ADAMS, 1D Tool, Excel VBA, Drop in Speed, Torque Build up.

Test Bench for Characterization and Durability Tests of Motorbike Clutches

In the paper, a new test bench for characterization and durability assessment of multi disc wet clutches for motorbike applications is presented. The design of the new test bench is inspired by the current SAE standards J2490 and J286 that refer to the testing of friction material for automatic transmissions wet clutches. Differently from the test bench described in the two standards, which is mainly designed to test the friction material, the test bench presented in this paper has been designed for testing the whole clutch, comprising all discs and the actuation mechanism. The lubrication system of the clutch utilized on the test bench is very similar to the one present on the actual motorbike. The design and instrumentation of the new test rig is analysed and discussed in the paper. The test bench has been used for the characterization of different motorbike clutches. The bench has proved to be able to measure the clutch characteristic for different temperatures and clutch wear levels. A very good repeatability of the tests has been achieved allowing for a comparison of different clutches design, friction material properties and operating conditions (temperature, ..). Some experimental results are presented and discussed in the paper.

Fuel Control Systems for Planetary Transmission Vehicles: A Contribution to the LPG-fueled Vehicles Community

The bi-fuel system vehicle (gasoline/LPG) has been developed for a long time because it has the ability to switch fuels, both built as an original equipment manufacturer (OEM) or as a modified vehicle. However, on vehicles with planetary automatic transmissions, additional control systems are needed to produce optimal performance, both on gasoline and LPG operations, especially on uphill roads. Old vehicles with planetary automatic transmissions are not equipped with road slope angle sensors, so on uphill roads and the driver has not mastered road conditions, the engine tends to stop suddenly. Therefore, this study aims to develop a fuel control system (LPG operation) on a planetary automatic transmission to control gear shifts based on the level of the road slope. A simulation with MATLAB Simulink we used to create a control system, with objective function and constraint defined. As a result, the control system can recognize the level of the road slope to control the speed gear shift. This control system is promising and reliable to be implemented in real conditions.

Rotor Behavior and Friction Torque Characteristics of a Gerotor Pump Used for Automatic Transmissions

Rotor behavior may affect the torque characteristics of gerotor pumps, but the measurement of the behavior has received little attention. Thus, in this study, we measure the rotor behavior of a gerotor pump used for automatic transmissions under various operating conditions. The experiments revealed that the inner rotor rotated near the middle of the cover wall and casing sidewall, slightly tilted with respect to them. The outer rotor rotated in the vicinity of the casing sidewall and came closer to the sidewall with decreases in the dimensionless parameter ?N??P (where ? [Pa?s] is the oil viscosity, N [s^(-1) ] is the rotational speed, and ?P [Pa] is the pressure difference). In addition, the eccentricity of the outer rotor was observed to increase with decreases in ?N??P. The inclination of the inner rotor and the approximation of the outer rotor to the casing sidewall may increase the driving torque of the pump. Taking the measured results on rotor behavior into account, a clear physical meaning is given to an existing mathematical model of viscous friction torque.

AUTOMATIC TRANSMISSIONS. COMPLEX OF ALGORITHMS OF “CLUTCH-TO-CLUTCH SHIFTS” TECHNOLOGY: ANALYSIS OF ARCHITECTURE, GENERALIZED STRUCTURE, DEVELOPMENT. PART 1

The article continues the series of the author publications, which considers the main provisions of the “Clutch-to-Clutch Shifts” (CTC) technology — technology for automatic controlling the switching of automatic transmission (AT) stages, used in the global mass production of vehicles, hybrid and battery electric vehicles. It provides high-quality shifts, brought to the level of continuously variable transmissions. Development of power units in recent years has led to a rapid increase in the number of AT stages, which is accompanied by a complication of kinematic schemes, designs, control algorithms and, in general, an increase in the role of mechatronic control systems (MCS) in ensuring their high technical level. Effectiveness of the CTC technology depends on the perfection of the algorithms used. But their composition is not specified, which, with a large amount of information, makes it difficult for potential users to navigate in this set. In this paper, we propose (for the first time in the Russian language) the generalized structure of a set of standard algorithms necessary for the implementation of this technology in the AT MCS, which is developed on the basis of their selection from a pre-formed database of patents and publications on the theory and technology of AT control, following classification and grouping by functional purpose. For each item of the structure, there are links to patents with matching names. Detailed descriptions of several typical CTC algorithms in the AT MCS of General Motors patents are given.