A new technique of active control is presented for enhancing the dynamic responses of full car systems with bias to ride comfort performance. A seven degrees of freedom full car model is used, and its performance is evaluated on a bump road and random road. The proposed scheme is a combination between traditional controller design methods with an algebraic estimator of perturbations that will be eliminated online. From the inputs and the outputs signals, the unmodeled phenomenon can be estimated and be subtracted for ensuring the proper functioning of the system. The precise mathematical model of the system is not required for the implementation of the control scheme and is replaced by ultra-local models. Furthermore, the effectiveness of the algebraic estimator of road profile is introduced for applying the excitation sources of the reference generator. The road profiles in front of the vehicle are estimated separately from the rear road profiles. The ride comfort is improved progressively with the novel controller configuration by 83% from the passive case. Further, pitching and rolling fluctuations are reduced by 80% and 85% respectively. The numerical simulations illustrate the effectiveness and the robustness against vehicle body mass deviation and nonlinear actuator saturation of the proposed control method compared to passive and Active Disturbance Rejection Controller based on Input Decoupling Transformation.

The present paper is aimed at the application of a substructure methodology, based on the Frequency Response Function (FRF) simulation technique, to analyze the vibration of a stage reducer connected by a rigid coupling to a planetary gear system. The computation of the vibration response was achieved using the FRF-based substructuring method. First of all, the two subsystems were analyzed separately and their FRF were obtained. Then the coupled model was analyzed indirectly using the substructuring technique. A comparison between the full system response and the coupled model response using the FRF substructuring was investigated to validate the coupling method. Furthermore, a parametric study of the effect of the shaft coupling stiffness on the FRF was discussed and the effects of modal truncation and condensation methods on the FRF of subsystems were analyzed.

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Power transmission systems are complex systems and their dynamic investigation requires much more CPU and computation time. For the purpose of studying the complicated global dynamics, the reduction approach is applied to simplify the complexity of connected problem. This work details the coupling technique and the identification of dynamic compartment of transmission system, from a known dynamic response of distinct multibody subsystems. The identification of transmission system was built by joining subsystem using the Frequency Response Function (FRF). This paper discusses the Frequency Based Sub-structuring (FBS) and the condensation methods. A description of these techniques and their importance were displayed. This approach was tested on a discrete system describing a dual stage reducer using receptance coupling. A parametric study was made to determine the sensitivity of the sub-structuring method by varying different parameters. In addition, the sensibility of random perturbation of coupling stiffness on the sub-structuring method was studied. The achieved results obtained by the coupling and the condensation approach were evaluated. The impact of reducer properties on subsystem response and the effect of neighbor parameter system on condensation methods were discussed. A great correspondence is shown between the simulated coupling technique and the full system results.

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