Papers by Author: Li Xin Guo

Abstract: Increasing consumption of the automobile make vehicle seat comfort characteristic paid more attention to. Damping performance as the third important factors is not allowed to ignore. A three freedom "human - seat" system model has been created for simulation. The result show that as the natural frequency f0 improved, the two resonance peak frequency of the system also improved, the growth of the first order resonance frequency is quite obvious, the second is less growth. And the higher the f0 the less change is. With the improvement of f0, the first order resonance peak to peak value obviously reduced, and the second order resonance peak to peak value increased. So, it is said that the higher the f0 the poor damping effect in high frequency area. The influence of ξ for the damping ratio of work frequency is not big, but the influence for the amplitude value is significant. Increase the natural frequency can make phase angle decreased when resonance, but the change of damping ratio, do not have obviously changes.

Abstract: Based on the building of non-stationary road surface excitation mode, a study on the active suspension control under non-stationary running condition was conducted using control, state feedback control strategy for linear systems with time-domain hard constraints was propose. The proposed approach was applied to design active suspension systems on the basis of a two-degree-of-freedom quarter car mode, Simulation results show that the proposed constrained controller can achieve a promising improvement on ride comfort, while keeping dynamic suspension deflections, dynamic tire loads and control forces within given bounds, even non-stationary running.

Abstract: The investigations about vehicle crossing process mainly use numerical simulation methods and, moreover, the relevant investigation is quite less. In this study, a three- dimensional fluid simulation model was established. By moving mesh technique, the three- dimensional transient simulation for vehicle crossing process was finished. The aerodynamics characteristics of vehicle crossing process with different lateral interval distances were analyzed. The analytical results show that the smaller the lateral interval distance, the more the transverse thrust between two vehicles during the crossing process. During the whole crossing process, the lateral force shows itself with repulsion in the beginning and attraction in the end. When the lateral interval distance of crossing is very small, the air disturbance due to crossing not only makes large affection to the lateral force but also influence obviously the positive pressure area of the front car bodywork.

Abstract: The characteristics of vibration and noise of an automobile have become important factors for evaluating automobiles. In this study, finite element modal analysis and harmonic analysis were used to analyze the dynamic characteristics of the bus bodywork. The analytical results show that vibration of ceiling board and floor board is large while the engine remains the idle running. The vibration of ceiling board and floor board are large during the engine running with the idle speed or the highest speed. In addition, the vibration of ceiling board and floor board also has peak values during the engine running with the maximum torsion moment. Therefore, for prediction of vehicle bodywork vibration and vehicle interior noise, the influence of the engine vibration on them should be considered in order to avoid resonance of bodywork boards and coupling of bodywork boards and interior acoustic field.

Abstract: The steering system of automobiles might vibrate under external excitation loading. Severe vibration of the steering system maybe bring the drivers uncomfortable and even result to noise and damage of some parts of the steering system. In the same time, it can not be satisfied with NVH design requirement of automobiles. In this study a three- dimensional finite element model of a steering wheel of automobiles was established and finite element static and dynamic analyses were conducted in order to validate dynamic characteristics and strength of the steering system. The simulation results can provide a reference for structural design of the steering system.

Abstract: Traffic accidents cause to a large quantity of personnel casualty and economic loss every year. The safety in vehicle crash has been one of important criterions in vehicle design. In this study a three-dimensional finite element model was established and the front crash process of car bodywork was analyzed. The simulation results show that the structure design of car bodywork is reasonable and of safety for the passengers. The investigation of this study not only validates the rationality of the car bodywork design but also provides a detailed numerical simulation model for further investigation as well as improvement and optimization of the car bodywork structure.

Abstract: In this study, we used Cricket equipments based on wireless sensor networks to study the pursuit-evasion strategy of multi-robots in a continuous map. In order to improve the efficiency, two new pursuit-evasion strategies were proposed. To meet the need of a continuous map, a greedy algorithm was utilized to deal with boundary problem when a pursuer or an evader was near the field boundary. The statistical results show the converging-attack pursuit strategy outperforms in pursuing the evader with different escaping strategies, such as randomly moving, active escaping strategy and vector-wards escaping strategy. The vector-wards escaping strategy is also effective in delaying the capture of evaders.

Abstract: The characteristic of vibration and noise of an automobile has become an important guide line to evaluate an automobile during the development of manufacturing and comfort of automobiles. In this study, finite element modal analysis was used to extract the acoustic resonant frequency and acoustic modal modes. The results show that the influence of vehicle seats on the acoustic modality should be considered in the acoustic design of vehicle interior cavum. Higher acoustic pressure areas for lower acoustic modalities mainly lie at the anterior/posterior ends or middle of the vehicle interior cavum.

Abstract: The vehicle riding comfort has become one of important factors of vehicle quality and receives more increasing attention. The driving smoothness of vehicles has immediate influence on the riding comfort of vehicles. In this study, the mechanical model and mathematics model of the 1/2 five degrees of freedom of a vehicle were established, as well as the pseudo- excitation model of road conditions for the front wheel and the rear wheel. By the pseudo- excitation method, the equations of the transient response and the power spectral density were established. After numerical simulation to vehicle vibration response of uneven driving, the results show that the pseudo- excitation method is more convenient than the traditional method and effectively solves the smoothness computation of vehicles while the pseudo- excitation method is used to analyze vehicle vibration under non-stationary random vibration.

Abstract: The localization of mobile robots is one of important problems for navigation of mobile robots. The wireless sensor network, i.e., Cricket wireless localization technology, was used to obtain motive condition of mobile objects in this study. The information transmission between the Cricket localization system and mobile robot system was achieved for localization, navigation and control of the mobile object. The errors of localization sampling data of the Cricket localization system vary within 3cm in a static condition. The Cricket localization system can meet the navigation requirement of the mobile robots.