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Since the vehicle AMT(Automatic Manual Transmission) has been developed to meet the requirements of high quality vehicles as well as hybrid vehicles, there are more and more tasks running on the ECU (Electronically Controlled Unit). Concerned with both function correctness and timing correctness, the scheduling of those tasks becomes important. A perfect scheduler, which distributes the proper task working during the proper time, can not only make the best use of the ECU, but also predict its capacity rationally. Compared with ordinary algorithm such as clock driven scheduler, static and dynamic priority-driven scheduler as well as round robin scheduler, this paper proposes an offline-designed Blended Timer-triggered Scheduler (BTTS) for AMT control. BTTS can coordinate periodical and event-triggered tasks in one envelope. It designates the available time slice for each task, which can make each critical task run at the proper time.

In this paper, a non-linear, rigid-elastic coupling multi-body system dynamic model is built for a city low-floor bus by using the integration of CAD/CAM/CAE techniques. Finite element analysis models of some flexible components are incorporated to the multi-body vehicle model. The non-linear properties of air spring and dampers are also included. Simulations are carried out in different operation conditions to investigate vehicle ride and handling performances. Based on the comparison of simulation results with field experiment results, the model is validated and the effectiveness of the modeling approach is proved.

The optimal control laws of front and rear wheels for a three-axle vehicle on complex typical path are studied based on the vehicle model of closed-loop control. The steering responses of the vehicle are improved through using steering state feedback. The actual vehicle model is considered as an uncertain system. The cornering stiffness of front and rear wheels and outer disturbances are variable over a limited range. The model-following variable structure control method is used for controlling front and rear wheels steering of the actual vehicle, so that the steering characteristics of uncertain vehicle model can follow the characteristics of reference model. Simulation results have demonstrated that the control system model can cape with the effects of parameter perturbations and outside disturbances.

In this paper, a method of virtual prototyping vehicles with twin-tube hydraulic shock absorbers is developed. The non-linearity of the absorber is studied based on multi-body system dynamics in the ADAMS environment. The unsymmetrical nonlinear hysteretic loop of the velocity characteristics is more accurate and practical than the piecewise linear representation typically used for shock absorber models. In conjunction with the practical geometric and physical parameters and motion restrictions for a car suspension system, the current virtual prototype is employed for dynamic simulation analyses of the absorber, and the numerical results are able to more closely match those obtained from the bench test. The current virtual prototype is validated and can be used as a subsystem for the optimal design of the shock absorber to match the whole car.

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.