Fuquan Zhao

Simulation research and programming of torque fluctuation of automotive steering system

The reason of steering torque fluctuation and its solution are investigated based on simulation software ADAMS and the practical problem of a specific Geelys vehicle in this paper. The above process is programmed into useful software in combination with the previous experience. Also the automatic optimization of steering system can be achieved in order to eliminate torque fluctuation at the early stage of automotive design.

Optimization Design of Suspension Structure Based on Multi-Body Dynamic Analysis

Operation stability of vehicles is directly impacted by suspension K&C. Multi-body dynamic CAE analysis and suspension K&C design are two tools for suspension design, which are fundamental both in theory and test. Test and simulation analysis will be conducted to a benchmarking vehicle in the development of a sedan. Geely has established its chassis lab, which is equipped with K&C test equipment, operation stability performance test equipment, and owns subjective appraisers. Testing data can be accumulated by suspension K&C and vehicle operation stability and riding comfort test on competing vehicles and developing vehicles. Through analysis of the test data, a performance comparison of different suspension structures, i.e. McPherson strut, torsion beam, and multi-link, thus suspension structures appropriate for different vehicles of Geely’s platforms are determined. In addition, optimization analysis is conducted to suspension structure and vehicle performance with ADAMS/CAR and CARSIM software to confirm the vehicle performance and system performance.

Research on Hydraulic Regenerative Braking System for Pure Electric Vehicle Based on AMESim

In order to increase the regenerative braking energy recovery and the dynamic performance of vehicle, the hydraulic braking energy recovery system is confirmed to use with the storage battery braking energy recovery system after comparing kinds of regenerative braking recovery plan and energy storage methods. Through PID control, simulation under ECE-15 cycle working mode and analysis of vehicle dynamic performance and energy recovery efficiency are conducted. The system simulation and analysis results show that using hydraulic regenerative braking system in pure electric vehicle can significantly improve the ability of vehicle’s start-acceleration and the increase in vehicle driving range reaches around 28 %.

Using Chassis Tuning Technology in Chassis Design of Car

Good or bad automotive quality mainly reflected in the advantages and disadvantages of vehicle performance, Tuning Technology use method of combining subjective and objective, adding simulation to give product correct position in the process of earlier scheming, to ensure product has good performance in the process of designing, to optimize product performance, and to ensure good chassis performance and vehicle performance. Summarize chassis tuning flow which provides basis for future car.

Research on the Impact of Derived Vehicle’s Weight Change on K&C and Vehicle Performance

Due to the weight deviation between derived vehicle model and the original one, it is necessary to determine whether to maintain the original performance or re-design it when designing its performance parts. The vehicle model is established in ADAMS by taking a Geely’s vehicle as the object. Adjusted according to the pre-set weight range of 3, 5 and 10 %, the model’s K&C, riding comfort, steering stability are simulated and equivalent cornering stiffness can be calculated to compare the results with that of the original one. When the change of axle load or vehicle weight are higher than 5 %, its suspension K&C and vehicle performance obviously differ from the original one, thus the relative performance parts needs to be redeveloped since performance parts cannot meet the requirements.

Research of section torsion beam based on multi-body dynamics

The three models of torsion beam and vehicle are constructed respectively based on three modeling solutions using one Geely car in order to accurately construct suspension model of torsion beam. And then different simulation analysis is performed, e.g. parallel wheel travel, opposite wheel travel, lateral force, pulse road test, steady-state circle. Moreover, simulation result and test value are compared. The comparison indicates that the simulation result of four section torsion beam model is similar to experimental value. It is accordingly presented that it is reasonable to construct a model by four section torsion beams when performing a simulation analysis on torsion beam suspension.

Research on automotive chassis tuning

The subjective evaluation of chassis handling and comfort, tuning activities and methods are introduced in this paper. Also the chassis tuning necessity and solution planning of tuning sample are described. Moreover, the main factors to adversely affect chassis handling and comfort are discussed. The chassis tuning can be performed by a combination of simulation and theoretical analysis.

Research of cruise pre-warning system based on MMW radar

The cruise pre-warning system is established based on millimeter wave radar. The cruise control system is preliminarily discussed in this paper. First, a braking model is constructed according to classical braking theory. And then identification and control (I&C) module is programmed by Matlab/simulink software. Moreover, multiple objects behind a car detected by radar are identified and controlled. An I&C module is connected to Carsim8.01 virtual radar module. The virtual object and simulation environment are set in Carsim and then simulation is performed. Finally, I&C strategy is verified by actual vehicle.