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During a car launch, the driving torque from driveline acts on brake disk, and may lead the pad to slip against the disk. Especially with slow brake pedal release, there is still brake torque applies on the disk, which will retard the rotation of disk, and under certain conditions, the disk and pad may stick again, so the reciprocated stick and slip can induce the noise and vibration, which can be transmitted to a passenger by both tactile and aural paths, this phenomenon is defined as brake groan. In this paper, we propose a nonlinear dynamics model of brake for bidirectional, and with 7 Degrees of Freedom (DOFs), and phase locus and Lyapunov Second Method are utilized to study the mechanism of groan. Time-frequency analysis method then is adopted to analyze the simulation results, meanwhile a test car is operated under corresponding conditions, and the test signals are sampled and then processed to acquire the features.

During the launch of a car, severe torsional vibration sometimes may occur in its driveline due to somewhat the slipping of the clutch, its intuitive sense for an occupant is the longitudinal vibration of the vehicle, referred to as the launch shudder whose characteristic frequency is from 5 to 25 Hz generally. As the main vibration sources of the driveline and its crucial nonlinear components, the variable stiffness and backlash of the gear meshing are considered, their impacts on the launch shudder are analyzed in this paper. Conformal mapping, finite element method and regression method etc. are the main approaches to calculate the variable meshing stiffness of a gear pair. If this stiffness is get, it can usually be substituted for its approximate analytical expression, just with finite harmonic terms, in Fourier Series form into Ordinary Differential Equations(ODEs) to calculate the vehicle responses with its nonlinearity considered.

Control of the Clutch is a complex system with multi-infactor, multi-goal and nonlinear properties, the fast tracing capability should be needed at the same time, so the fuzzy control is suitable for it. The difficulty of the clutch fuzzy control is how to analyze its stability. In this paper, the theory of Lyapunov and linear approximation is applied to analyze and design the stability of the clutch fuzzy control, which is a practical method in analysis of the stability of nonlinear systems.

Based on analysis problems of vehicle with present automatic transmission, an Intelligent Shift Strategy(ITSS) is proposed for the first time. Three kinds of information, which are the driver intention, the vehicle dynamic characteristics and the outside environment, are included in it, and the humachine technology is applied to decide shift strategy.

Difficulty of the Automatic Transmission(AT) is to properly control its clutch while the vehicle starts. An intelligent hierarchical controller is proposed in this paper. The upper of it is an intelligent PID controller based on a driver's experience and an expert's knowledge. It gives real time signals to the lower controller and coordinates the control between engine and clutch. The lower Variable Structure Fuzzy Controller (VSFC) executes the upper controller's direction signal.

The cruise control as one of promising vehicle active control has been receiving a considerable attention in recent years, so the related problems are discussed in this paper. Mathematical model of the engine under the steady state and general dynamics equation of the Continuously Variable Transmission(CVT) are given, the regulating principle of the operating state of the engine is analyzed, and the conjugate gradient method employed to solve the optimal control problem of the vehicle in the cruise control is described, so the operating state of the engine could be controlled. At end of paper, some results are provided to verify the approach based on the vehicular powertrain with a hydromechanical CVT.

Although Hydrostatic Transmission System (HTS) had been used in many places, such as machine tools, agriculture machinery, construction machinery, and vehicles, it had not been used in good performance. Twenty years ago many people began to design new hydrostatic transmission with higher efficiency. Hydrostatic Energy Storage Transmission System (HESTS) is one of new hydrostatic transmission system with higher efficiency. HESTS is more fit for being used in vehicle that is always running in undulating ground or starting and braking frequently. Construction of vehicular HESTS was analyzed, mathematical model of vehicular HESTS was established. The needed control strategies of vehicular HESTS were analyzed because there are many variables would be controlled in the new transmission system.

Jet-wake flow and secondary flows are undesirable in torque converters as they are responsible for flow losses and flow nonuniformity; that is, jet-wake flow and secondary flows negatively affect the torque converter performance. Therefore, it is very important to investigate and minimize the undesirable flows to decrease flow losses in torque converter. However, the existing studies are limited to employ geometry design parameter modifications rather than focusing on the actual causes and intrinsic physical mechanism that generate the flows to reduce the flow losses. In this paper, Calculation model of a torque converter is presented first and a three dimensional CFD code was used to simulate the internal flow field of a torque converter. The simulation results coincide with experimental measurements, which verifies the validity of the method. Based on flow field calculation results, the internal flow field of impeller, turbine and stator were analyzed, respectively.

The city buses start and stop frequently, therefore significant amount of kinetic energy is wasted on friction plates. In order to retrieve this amount of energy, various feasible and efficient energy storage systems have been suggested by researchers to reuse the energy to improve the efficiency of the city bus. Due to small size, high energy density, cleanliness and easiness to absorb/reuse the energy, the storage system of flywheel is hopeful to be coming into wide use. In this paper, a dynamic model is analyzed to study the characteristics of the system using time series. Finally, comparison between simulation and experiment is given.

A novel hydraulic transmission system-Hydraulic Energystorage Transmission System(HESTS) which contains a Hydraulic Continuously Variable Transmission(HCVT) and a flow controllable accumulator is proposed. The power flows of the HESTS has been analyzed. Computer simulations show the potentialities of improving fuel economy of a vehicle with a HESTS. A fuzzy logic controller with two regulating factors is developed to improve the performance of the HESTS with variable loads.

In this paper, the system identification theory and method using dynamic neural networks are presented, the multilayer feedforward networks employed, the backpropagation with adaptive learning rate algorithms proposed. Finally the comparision of network output with that of the hydrostatic drive system of secondary regulation is given, and output error, sum-squared error et al, or the results that embody the effect of system identification given sine input to it are provided.

In this paper the working principle of hydraulic branch of the hydromechanical transmission is introduced, dynamic characteristic analysed, its actuating medium enclosed in the working space consists that of pump, soft pipeline and motor considered to be a torsional hydraulic spring whose torsional stiffness and damping provided. The multidegrees-of-freedom of the concentrated mass-elasticity discrete mechanics model is utilized to analyze the transmission system, and the finite element method is employed to model it, the torsional natural characteristic of the system are calculated, these provide the scientific basis for structural modification of controlling the vibration and noise.

In this paper the nonlinear system identification theory and method using neural networks are presented, the multilayer feedforward networks employed, the backpropagation learning algorithm proposed. The inputs of the networks are consisted of angular velocity and throttle angle, and outputs torque of the engine, finally the comparision of simulation result with that of experiment and other results that embody the effect of system identification are given. Relative studies revealed that the nonlinear system identification for the engine of automated automobiles using neural networks can be effective.

In this paper, the intelligent control theory and method using neural networks are presented, the multilayer feedforward networks employed, the back propagation learning algorithm proposed. Finally the angular velocity control result of the hydrostatic drive system of secondary regulation with such type of control is provided. Relative studies revealed that the intelligent control for the system using neural networks can be effective.

The undesired shifting phenomenon(USP) occurs easily under the braking or climbing conditions etc., and its impact is the discomfort to the passengers or cause of vehicle's state contrary to the driver's intention, meanwhile, the wear of the clutch and synchronizer is increased, so their lifetime are greatly shortened. To the vehicle with dual clutch transmission (DCT), undesired shifting phenomenon will lead to frequent and unnecessary actuation of synchronizer for the use of pre-engagement synchronizer in the shifting control; therefore, its occurrence should be eliminated as far as possible. In this paper, the process of the undesired shifting of the vehicle with DCT is elaborated, then the generating cause of USP is described based on directed graph.

For high levels autonomous driving functions, the Decision Layer often takes on more responsibility due to the requirement of facing more diverse and even rare conditions. It is very difficult to accurately find a safe and efficient lane change timing when autonomous vehicles encounter complex traffic flow and need to change lanes. The traditional method based on rules and experiences has the limitation that it is difficult to be taken into account all possible conditions. Therefore, this paper designs a lane-changing decision algorithm based on data-driven and machine learning, and uses the DQN (Deep Q Network) algorithm in Reinforcement Learning to determine the appropriate lane-changing timing and target lane. Firstly, the scene characteristics of the highway are analyzed, the input and output of the decision-making model are designated and the data from the Perception Layer are processed.

Centrifugal Pendulum Vibration Absorber (CPVA for short) is used to absorb torsional vibrations caused by the shifting motion of the engine. It is increasingly used in modern powertrains. In the research of the dynamic characteristics of the CPVA, it is necessary to obtain the real motion of the pendulum to compensate the fitting performance of mathematical model. The usual method is to install an angle sensor to measure the movement of the pendulum. On the one hand, the installation of the sensor will affect its movement to a certain extent, so that the measurement results do not match the actual motion. On the other hand, the motion of the pendulum is not only the rotational motion around the rotational axis of the CPVA rotor, but also has translation relative to it. As a result, it is difficult to obtain accurate motion only by the angle sensor. We proposed a non-contact centrifugal pendulum motion measurement method.

Shift quality is an important indicator to measure the performance of dual-clutch transmissions (DCT). To obtain optimal driving comfort and reduce the vehicle jerk as much as possible, this paper proposes an integrated gearshift controller to control the engine and the on-coming clutch in inertia phase. First of all, a dynamic model of DCT during gearshift is established. Key factors determining shift quality are analyzed. In order to reduce the vehicle jerk, a reference trajectory of the engine speed and the derivative of the desired torque transferred by the on-coming clutch in inertia phase are programmed respectively. A back-stepping sliding mode controller (BPSMC) is designed to make the actual engine speed track the reference trajectory and an incremental proportional-integrative (PI) controller is designed to make the actual clutch torque to track the desired clutch torque.

The control of vehicle clutches is somehow different of non-linearity from others and needs consideration of control matching between the clutch and engine. For that reason, an expert fuzzy control is proposed in this paper, which is integrated with expert control, fuzzy control and hierarchical control. By real vehicle test results, the control function is verified.

Vehicle launch shudder is the terminology used in automotive industry to describe severe longitudinal oscillation during clutch engagement under start-up condition. This paper presents and implements detailed investigation for dry-clutch engagement and disengagement process, in order to deeply analyze vehicle launch shudder phenomenon which seriously deteriorates ride comfort. Firstly, diaphragm spring and cushion spring and link strip, which are three elastic components related to dry-clutch engagement and disengagement process in axial direction, are studied for their elastic properties, respectively, to obtain relationship between load and deflection. The elastic properties of these three elastic components are taken into considerations to establish nonlinear relationship between release bearing travel and clutch clamp force.