NVH Optimization of Range Extender Engines by Electric Torque Profile Shaping
Range extender operation in an electric vehicle should be imperceptible to the driver from a noise/vibration standpoint. Rolling torque compensation allows virtually vibration-free range extender engine operation by utilizing a balanced counter-rotating inertia that is geared to the cranktrain. The combustion process results in engine torque fluctuations that could cause gear rattle in such a system due to a combination of torque reversal and lash in the geared connection. This brief paper addresses the problem of gear rattle in a rolling torque compensation system. First, a preloaded split gear is introduced as a potential mechanical solution to eliminate the clearance in the gear contact zone. In addition, an approach for a mechatronic solution involving active shaping of the generator torque is introduced. This methodology includes measurement of the combustion engine torque via cylinder pressure indication data, calculation of allowable torque limits, and the determination of a generator torque profile to address gear rattle. A multicriteria cost function is introduced to determine the optimal torque within the established constraints. Variations of the cost function are investigated with respect to their impact on efficiency and range extender acoustics.
Grey FNN control and robustness design for practical nonlinear systems
To ensure asymptomatic stability and improve vehicle ride comfort, this paper develops a fuzzy neural network (FNN) based on the evolved bat algorithm (EBA) to design adaptive backstepping controllers with gray signal predicators. A recoil method is used to evaluate the nonlinearity of the controlled systems and to derive the control law which is evolved for the tracking of the signals. A group of grey differential equations are applied for the grey model (GM) (n, h), which is an active model where h is the number of considered variables and n is the order of the grey differential equations. In the article, the Discrete GM (2.1) is used to obtain the advanced motion of the nonlinear system, so that the command controller can prove the Lyapunov stability and feasibility of the entire scheme through the Lyapunov-like lemma. The controller design criteria are demonstrated for mechanical elastic wheels (MEW) to establish a viable mathematical framework for the new wheels.
Modulation of neuronal serotonin uptake by a putative endogenous ligand of imipramine recognition sites.
Imipramine inhibits the serotonin uptake by binding with high affinity to regulatory sites of this uptake located on axons that release serotonin. The number of imipramine recognition sites located on crude synaptic membrane preparations is reduced by two daily injections of imipramine or desmethylimipramine for 3 weeks. When the binding sites for [3H]imipramine are down-regulated the Vmax of the neuronal uptake of serotonin is increased. Moreover, in minces prepared from the brain hippocampus of rats receiving imipramine in a dose regimen that reduces the number of [3H]imipramine recognition sites, the efficiency of imipramine as a blocker of the serotonin uptake is diminished. Hence the high-affinity binding sites for [3H]imipramine may have a physiological role in modulation of serotonin reuptake. Probably this is mediated by an endogenous effector of these regulatory sites. A nonpeptidic constituent of rat brain capable of displacing [3H]imipramine from its high-affinity binding site and of inhibiting the serotonin uptake in a dose-related manner has been extracted and its partial purification is described.