Designing guiding device of suspension made of aluminum alloys for multi-purpose driverless vehicle using topological optimization method

Abstract

Introduction (problem statement and relevance). Currently, mobile driverless transport and technological means are widely used for automation of work processes and remote control over a vehicle, excluding immediate human attendance in dangerous areas. Generally, such vehicles feature an electric powerplant while using batteries as energy storage devices. In order to reduce the number of operations during such vehicle driving, it is convenient to use a running gear design that is symmetric relative to its longitudinal and transverse planes. Reducing energy consumption will allow increasing in energy efficiency when performing transport and other technological operations. One of the ways to improve energy efficiency is to reduce the weight of elements of such vehicles. This can be achieved by using materials with high specific strength, such as aluminum alloys, and by developing optimum loading patterns for such element structures. The object of the study is a driverless 4x4 vehicle with the fully loaded weight of 830 kg. The research subject is the methods of optimum designing of vehicle load-bearing structures and their use taking into account the operating conditions. The purpose of the study is to develop the methodology for designing suspension elements for a vehicle with a symmetric design of the running gear made of aluminum alloy taking into account the loading modes.Methodology and research methods. The paper presents a dynamic mathematical model of the wheeled vehicle for determination of loads created in a program for rigid bodies dynamics modeling, the methodology for bringing the loads to one suspension unit (front left wheel), loading patterns for suspension elements obtained with the use of topological optimization and strength calculations performed with application of the finite element method confirming the design functionality.Scientific novelty and results. The paper presents the method for bringing the loads obtained for all suspension elements to the front left point, since the driverless vehicle has a symmetrical running gear design. Taking this into account, a rigid-body dynamic model and an algorithm for processing the obtained loads for a finite element model were developed. Also, typical modes of vehicle loading were selected. The loads were distributed among the following types: operational, extreme and emergency ones. Recommendations were given for the choice of restrictions when conducting topological optimization depending on the mode type. As a result, loading patterns for suspension guiding device elements were obtained. Check calculations were carried out to confirm the design functionality.Practical significance. The obtained results can be used in development of highly loaded elements of wheeled vehicles.