Abstract

The focus of the paper is an investigation and evaluation of energy efficient solutions in IP over WDM core networks using as a foundation, a hierarchy of hibernation modes implementing different degrees of node groupings and fibre links establishment that support a sleep state. It seeks to embed this groups-nodes strategy into an intelligent control plane implementing routing schemes targeting energy consumption, adaptive signalling and traffic engineering. A Group-Nodes mechanism is proposed as a function of topology and node distribution based on a fixed (or geographical) and random (or ownership) principle. The impact of the proposed technique on energy saving and network performance is assessed; results are presented and evaluated for various scenarios. Evaluation of this methodology indicates potential reduction in power consumption from 7 % up to 15 % at the expense of reduced network performance. Document type: Part of book or chapter of book

Abstract

At least two different actuators work in cooperation in regenerative braking for electric and hybrid vehicles. Torque blending is an important area, which is responsible for better manoeuvrability, reduced braking distance, improved riding comfort, etc. In this paper, a control method for electric vehicle blended antilock braking system based on fuzzy logic is promoted. The principle prioritizes usage of electric motor actuators to maximize recuperation energy during deceleration process. Moreover, for supreme efficiency it considers the battery’s state of charge for switching between electric motor and conventional electrohydraulic brakes. To demonstrate the functionality of the controller under changing dynamic conditions, a hardware-in-the-loop simulation with real electrohydraulic brakes test bed is utilized. In particular, the experiment is designed to exceed the state-of-charge threshold during braking operation, what leads to immediate switch between regenerative and friction brake modes. Document type: Part of book or chapter of book

Abstract

The trajectory phase–plane method provides an increased significance to the analysis of stability and performance of the controllers for complex nonlinear plants. The aim of this study is the stability and performance analysis of a fuzzy logic controller for anti–lock braking system applying the trajectory phase–plane technique. The controller’s main task is to hold optimal braking performance by recognizing road surface. The stability and performance of the anti–lock braking system controller are examined with respect to the conventional friction brake and electric motors separately. The applied methodology allows for visual assessment of the stability and performance of studied nonlinear systems. The work refers to hardware–in–the–loop simulations conducted at the Technische Universität Ilmenau. The results demonstrate that the fuzzy logic controller is stable independently of the employed actuator. Moreover, the electric actuators allow for faster convergence and more accurate tracking of the optimal wheel slip.