چكيده به لاتين
The benefit of most road-holding with the benefit of tide comfort is always considered by most car manufacturers and consumers. Due to the different frequency range of satisfying these two goals, the possibility of providing both goals at the same time has been a serious challenge for researchers. Variable geometry suspension system with the advantages of active suspension and very low energy consumption due to changes in angles and position of suspension components, is a good option to replace existing suspensions. This dissertation uses a single-link active variable-geometry suspension system in a Ferrari F430 passenger car, as well as a simple, multi-dimensional adaptive sliding mode controller to further improve vehicle dynamics, including glued road, passenger comfort and lateral stability. The car is used. This controller is implemented for the first time in the series active variable geometry suspension. Among the reasons for choosing it, in addition to cheapness and simplicity of calculations, is the ability to implement in nonlinear systems and resistance to perturbations and system uncertainties. For this purpose, after introducing and reviewing the history of the mentioned system, the research field and its current challenges have been analyzed. Then, to study the effects of the mentioned suspension system, common controllers of previous studies such as simple and adaptive fuzzy PID controllers and LQR have been used. The main weakness of these controllers has been high complexity, weakness against uncertainties and low performance improvement. To compensate for this defect, a simple and multidimensional adaptive sliding mode controller has been used to study the model of the whole vehicle in different maneuvers of longitudinal and transverse driving in an asymmetric unevenness. In this study, the angular accelerations of the vehicle swing and roll along with the vertical acceleration of the vehicle mass center were used as the control input of the multidimensional sliding mode. Fuzzy technique has also been used to eliminate additional fluctuations in the vehicle response. The output of the results of the multidimensional fuzzy slip mode controller showed a 22 to 55% improvement in the vehicle's dynamic characteristics compared to the inactive suspension mode and a 10 to 21% improvement over conventional controllers. The analysis of these results, presented in Chapter 4, shows a significant improvement in the vehicle acceleration and rolling angle accelerations of about 40% and 30%, respectively, compared to the inactive suspension mode. This reduction in acceleration creates lateral stability and prevents the car from overturning. Also, to ensure occupant comfort, the vertical acceleration of the vehicle mass center is reduced by about 25% and the vertical acceleration of the suspended mass by about 40% in the proposed controller relative to the inactive mode. Also, the amount of compression of the car tire during driving in lateral wind maneuvers, changing the driving direction and moving the straight path, shows a 30% improvement between the passive suspension and the geometry of the active variable series. The study did not consider aerodynamic dynamics, and also assumed that the car tire was in constant contact with the road surface and that the angular velocities of the rotating links of the suspension were equal.
