Specifying a hydraulic regenerative braking system for an articulated urban delivery vehicle
Previous research has shown that hydraulic systems offer potentially the lightest and smallest regenerative braking technology for heavy goods vehicles. This paper takes the most practical embodiment of a hydraulic system for an articulated urban delivery vehicle and investigates the best specification for the various components, based on a simulated stop-start cycle. The potential energy saving is quantified.
Vehicle dynamics control with energy recuperation based on control allocation for independent wheel motors and brake system
This work proposes an optimal control allocation method for the brake system and the wheel motors of an electric vehicle. The realisation of the method is proposed for vehicle dynamics control and energy recuperation. The control allocation takes into account temperature of electric motors, SOC and voltage of battery, vehicle velocity, fault situations, wheel slip, and vehicle subsystem prioritisation depending on parameters of vehicle dynamics. To illustrate the functional properties of the control allocation method, the corresponding simulation study is performed for the straight-line braking and ‘sine with dwell’ cornering. The simulations use a number of mathematical models including the 14 DoF model of vehicle motion and the models of electric vehicle systems. The simulation results confirmed effectiveness of the proposed approach both for regenerative braking and vehicle stability.
Computer-Aided System of Virtual Testing of Gas Turbine Engines
The article describes the concept of a virtual lab that includes subsystem of gas turbine engine simulation, subsystem of experiment planning, subsystem of measurement errors simulation, subsystem of simulator identification and others. The basis for virtual lab development is the computer-aided system of thermogasdynamic research and analysis “ASTRA”. The features of gas turbine engine transient modes simulator are described. The principal difference between the simulators of transient and stationary modes of gas turbine engines is that the energy balance of the compressor and turbine becomes not applicable. The computer-aided system of virtual gas turbine engine testing was created using the developed transient modes simulator. This system solves the tasks of operational (throttling, speed, climatic, altitude) characteristics calculation, analysis of transient dynamics and selection of optimal control laws. Besides, the system of virtual gas turbine engine testing is a clear demonstration of gas turbine engine working process and the regularities of engine elements collaboration. The interface of the system of virtual gas turbine engine testing is described in the article and some screenshots of the interface elements are provided. The developed system of virtual gas turbine engine testing provides means for reducing the laboriousness of gas turbine engines testing. Besides, the implementation of this system in the learning process allows the diversification of lab works and therefore improve the quality of training.