For the deficiencies of traditional PC-based vehicle fault diagnostic system, this paper proposes a kind of standardized PC-based vehicle fault diagnostic system which by the standardized diagnostic interface device and diagnostic application software, selects the MDI diagnostic device which conformed to SAE J2534 standard, studies the communication mechanism of MDI and SAE J2534 standard content, optimizes the data read rate, develops the diagnostic application software using the ideas of hierarchical architecture and function modularization. Through vehicle testing and analysis, this system allows the fault diagnosis, maintenance help, real-time monitoring and online refresh for vehicle electronic control system, has a good versatility and scalability, has a reference for developing standardized diagnostic device and provides the favorable tools for Vehicle Diagnosis and Maintenance.
In order to ensure the reliability and safety of the Flex Ray bus communication network, based on the study of AUTOSAR network management and the characteristics of Flex Ray, aiming at the shortage of AUTOSAR network management in the new node's joining process and the fault handling, we improve conditions on the node state transition. Fault detection is realized by sending adding fault detection of network management protocol data unit; In the time of the new node's joining, the flag bit Repeat Message is sent to avoid sending the Repeat Message all the time. Finally, CANoe simulation software is used to verify the feasibility of the method.
The steering wheelu0027s vibration level of a certain truck in idling state israther high. Finite element modal analysis and modal test method are conducted, combined with vibration test results, the fact that the natural frequency of steering system is closed to the second order excitation frequencyof the engine is figured out. Besides, the X and Y direction modal coupling is serious. Then, the influence of wheel position adjustment on steering system modes is analyzed. And back-top position is determined to be reference position as frequency separation in idle condition. Finally, according to the structurefeature of the steering system, feasible improvedschemeson bracing structure optimization and steering wheel lightweightare proposed. At last, the validity of the schemesis verified via the vibration test of steering wheel in idling state.
As the phenomenon of many rollover accidents of the concrete mixer truck,it has introduced the principle of differential braking control strategy,and designed a control system towards concrete mixer truck to avoid rollover accidents.Based on ADAMS/Car and Simulink the analysis has proved that through choosing the reasonable rollover limit value,differential braking control strategy can prevent rollover accident caused by high speed turning,but has nearly no influence on safe running.
Soil bin test has become one of the most important research techniques in vehicle terramechanics.The latest developments of several typical soil bin test apparatuses are reviewed in this paper with emphasis laid on their functions and technical characteristics.Accordingly,the prospect of soil bin test is proposed.Finally,limitations in the domestic study of soil bin test are pointed out through comparative analysis and feasible proposals are put forward specifically.
As a kind of high-speed rotating machinery,vehicle turbocharger is supported on floating ring bearings.Under high speed and high temperature working conditions,the strongly nonlinear oil film force can make the rotor system complicated dynamic phenomena at a large speed range.A rotor dynamic model is established by using short bearing model of double oil films combined with the rotor discretization model of the turbocharger in this paper,the results of numerical simulation are described at the rotational speed rate of the floating ring relative to working speed,characteristic FFT spectrum and oil eccentricity respectively,and comparative analysis of such aspects to explain the double oil film instability characteristics of turbocharger rotor system supported on full floating bearings.
This article used FEM to analysis lower control arm of electric vehicle’s McPherson suspension.First,with the method of kinematic analysis,load obtained loads on the lower control arm.Followed by respectively assigned to lower control arm of the same thickness of steel material and aluminum material,and analysis it with the method of inertia relief.Finally,we use the largest deformation as constraints of size optimization on the lower control arm made of aluminum materials.The results showed that lower control arm made of aluminum materials can effectively reduce their weight to ensure that the premise of static and dynamic performance.
Some reasonable machining parameters were designed to study the cutting test of 304 austenitic stainless steel.Surface roughness,microstructure and work hardening were used to analysis of the influence of machining parameters on surface properties of 304 austenitic stainless steel.The results showed that the feed rate is main influencing factors of surface roughness,surface roughness.The increases with increasing the feed rate.The influence of the cutting deep and cutting speed on the roughness is smaller.The influence of tool wear on the martensitic transformation is larger,and the content of the martensite is related with strain;feed rate and cutting deep have the greatest influence on work hardening.
This article has set up the structural FE model of some mining locomotive by HyperMesh.The modal analysis is made by NASTRAN.A modal sensitivity analysis is performed through OptiStruct,based on the FEM structural and corresponding sensitive area identified.We set increasing the first torsional frequency of the cab as the main objective.By means of the structure optimization,we improve the vibration character.
Through the modal analysis of the finite element model for a engine hood,two structure optimization schemes have been put forward by using topology optimization method to optimize the design of its structure.A structural optimization scheme was confirmed after further analysis and comparison of its manufacturing process characteristic.At last,the structural stiffness of the optimized hood was verified and the overall performance of it was also improved.The purpose of optimization was achieved.The use of computer-aided engineering(CAE) could offer the right direction of design to engineer,shorten development cycles,reduce development costs and bring economic benefits.
In order to meet the de-ice demand of commercial vehicle’s windshield and side glass while shortening the development time and reducing the cost of the vehicle,simulation of de-icing of the vehicle is becoming very important.Basing on K-emodel,analysis one commercial vehicle,and then modify the duct to optimize the flow,at the end simulate the windshield and side glass de-icing process.
Through the combination of the different shift implementations in the automatic transmission, the research try to find the motion relationship and the rule in the each gear position. Then based on simulation software AMESim with Matlab/Simulink established a seven-speed automatic transmission in the model and through cosimulation, the automatic transmission model is validated. The results show that the transmission of this model rule fully meet the actual situation. Through the process of modeling and simulation, a new method for the automatic transmission of this type of modeling.
Regarding one integral coach as the object and applying the finite element method and nonlinear theory to model the coach and simulating the 100% head-on collision by the general explicit mechanical analysis software, we studied the deformation degree of the body frame structure and the characters of the deformation.Besides, the size of passengers' surviving space was analyzed. In addition, we evaluated the crashworthiness and safety performance of this panssenger vehicle. All these works provide relevant information for further study.
Building a vehicle dynamic system simulation model by Simulink, this simulation can be obtained for a given engine power performance requirements under the road environment and speed conditions, and compare with AMESim model calculation results. The results show that:Simulink simulation model can freer modeling and has a higher accuracy then AMESim, and facilitate to expand, it can provide a good platform for refine the engine study.
This paper introduced the structure development tendency of Diesel Engine SCR system and improved the structure of a compact SCR system.It analyzed the flow field of the spiral mixer using CFD software and evaluated the flow distribution uniformity of different situations with/without spiral mixer and with structure improved mixer.The calculation results show that the spiral mixer changed the flow velocity distribution characteristics in the axial section and velocity increases from the central axial to the wall around.In addition,making appropriate holes in the entrances and exits of the spiral mixer can reduce backpressure and promote uniformity of the flow distribution.
With the development of automobile computerize services, EMC problems have become one of the key factors to affect the handling, control and safety of vehicles. This paper demonstrates the planning of automotive EMC test laboratory. And the process parameters on anechoic chamber, turn table and dynamometer, HVAC and civil constructions are also introduced.
Parameter optimization of hybrid electric vehicle plays an important role in reducing fuel consumption and reducing emissions.For HEV highly non-linear system,an HEV dynamic simulation model is built with software AVL CRUISE and MATLAB.With using improved genetic optimization algorithm NSGA-II,to simultaneously optimize the parameters of the hybrid vehicle transmission and control strategy.The optimized results show that this method improves fuel economy and emissions performance guarantee dynamic premise.
Through theoretical analysis and the actual test,this paper did some research of the single point control method and the double point control method about tractor-semitrailer's electronically controlled air suspension system.It is not only pointed out the advantages and disadvantages of the two methods,but also provided some advices on the practical application.
Main reducer bevel gear is the main component of vehicle driving axle,and its meshing quality plays an important role on drive axle performance,service life,noise and vibration.The analyzes paper the main reducer gear’s contact fleck and transmission error by using the MASTA software and using them to evaluate the gear’s meshing quality.Compared with traditional methods,this method can avoid the qualitative evaluation relying on the experiences,and effectively reduce the experiment cost and shorten development cycle by using specialized software for modeling and simulation analysis.It can provide references for the developments and applications of new drive axle main reducer gear.
