Pavement roughness identification research in time domain based on neural network

A new simulation study method based on general regression neural network (GRNN) is proposed for identifying the pavement roughness in the time domain. First, a seven degree-of-freedoms vehicle vibration model is estbalished for the vehicle’s riding comfort analysis. The vertical acceleration and pitching angular acceleration of vehicle body centroid are calculated by simulation. The nonlinear mapping relations between the two above accelerations and pavement roughness in time domain are built by GRNN, and then the pavement roughness is identified by training the networks. Finally, the vertical acceleration and pitching angular acceleration of the vehicle body centriod are acquired by ADAMS/View virtual experiment simulation and the result are used to identify pavement roughness. In the end, the availability for identifying the pavement roughness by GRNN is confirmed

Research on vehicle handling inverse dynamics based on optimal control while encountering emergency collision avoidance

Vehicle driving safety is the urgent key problem to be solved of vehicle independent development while encountering emergency collision avoidance with high speed. And it is also the premise and one of the necessary conditions of vehicle active safety. A new technique for vehicle handling inverse dynamics which can evaluate the emergency collision avoidance performance is proposed. Firstly, the steering angle input of 3-DOF vehicle mode is established. The steering angle input imposed by driver is the control variable, and accurately tracking the expected path was the control object. The optimal control problem can be converted into a nonlinear programming problem while using the state variables conversion, which was solved by the sequential quadratic programming (SQP) algorithm. The results show that vehicle can well track the expected path in high speed

Vehicle steering wheel angle identification research based on dynamic program method

In order to improve the safety of vehicle manipulation as well as to provide a theoretical basis for the study of vehicle steering system and intelligent parking systems, a new method of vehicle steering wheel angle identification is presented – the dynamic program method. First, three freedom degrees of vehicle model is established. Then Bellman’s principle of optimality is used for minimizing the objective function. The dynamic optimization model of the load identification that the yawing angular velocity, lateral acceleration and vehicle body roll angle identified the steering wheel angle and angle velocity. The result shows that the dynamic program method for the steering wheel angle identification problem containing the measurement noise has strong adaptability, high accuracy and good anti-jamming capability

Vibration performance analysis of vehicle with the non-pneumatic new mechanical elastic wheel in the impulse input experiment

A non-pneumatic tire appears to have advantages over the conventional pneumatic tire in terms of flat proof and maintenance free. A mechanical elastic wheel (MEW) with a non-pneumatic elastic outer ring which functions as the air of the pneumatic tire was presented. The structure of MEW is non-inflatable integrated configuration and the effect of hinges is accounted for only in tension. To establish finite element model of MEW, various nonlinear factors, such as the geometrical nonlinearity, material nonlinearity and contact nonlinearity, were considered. Load characteristic test was conducted by tyre dynamic test-bed to obtain force-deflection curves. And the validity of the finite element model was validated through load characteristic test. The vehicle vibration performance respectively based on the MEW and the radial tire was compatative studied under pulse input experiment conditions. The result showed that the vehicle concluding the new mechanical elastic wheel met the vibration performance requirements and vibration performance regularity of pneumatic tire. The results could be used as the thesis reference for the improvement of new mechanical elastic wheel

Research Method of Tyre Contact Characteristics Based on Modal Analysis

Tyre is the only connecting part between the vehicle and the road, which provides all the vehicle driving, steering, and braking force. Accuracy tyre dynamics models are increasingly needed. Because of the structure nonlinear and complexity of contact state, how to establish effective tyre model is always the difficulty of vehicle dynamics modeling. Based on the idea of modal parameters modeling, establish the quantitative static tyre model in the vertical direction and research the effects of modal root and tread model on this method. With the tyre vertical load on the road, research the pressure and deformation features in the tyre contact patch and the interrelation between the horizontal load distribution, contact length, and sinking amount. Use the iterative method to establish tyres static vertical model on the horizontal road. The theoretical calculation and experiment results indicate the relation curves of vertical force distribution and sinking amount, vertical load, and length of contact patch and show good agreement on the qualitative and quantitative aspects

Analysis of Heat Dissipation Performance of Battery Liquid Cooling Plate Based on Bionic Structure

To provide a favorable temperature for a power battery liquid cooling system, a bionic blood vessel structure of the power battery liquid cooling plate is designed based on the knowledge of bionics and the human blood vessel model. For three different discharge rates of 1C, 2C, and 3C, FLUENT is used to simulate and analyze the heat dissipation performance of the liquid cooling plate with a bionic vascular structure. The influence of the pipe distance (A1 and A2) at the coolant outlet, the thickness of the liquid cooling plate, the inner pipe turning radius R of the pipe in the channel, and the mass flow of coolant on the heat dissipation performance are studied. The results show that the pipe distance (A1 and A2), plate thickness, and inner pipe turning radius R have significant effects on the heat dissipation of the liquid cooling plate, especially under a 3C discharge. In addition, the channel area at the coolant outlet also has great influence on the heat dissipation performance of the liquid cooling plate, and the variable width optimization of the channel area at the outlet greatly improves the heat dissipation performance of the liquid cooling plate. Increasing the inlet mass flow rate can improve the heat dissipation capacity, but at the expense of a pressure drop. A verification experiment is designed for 3C discharge. The results show that the error between the experiment and simulation results is within 9.8%; therefore, the simulation is accurate, and the liquid cooling plate has a significant heat dissipation effect

An Atomic Cross-Chain Swap-Based Management System in Vehicular Ad Hoc Networks

The blockchain-based management system has been regarded as a novel way to improve the efficiency and safety of Vehicular Ad Hoc Networks (VANETs). A blockchain-based scheme’s performance depends on blockchain nodes’ computing power composed from the road-side unit (RSU). However, the throughput of blockchain-based application in VANETs is limited by the network bandwidth. A single blockchain cannot record large-scale VANETs’ data. In this paper, we design an atomic cross-chain swap-based management system (ACSMS) to boost the scalability of blockchain-based application in VANETs. The blockchain-based public-key encryption with keyword search is further introduced to protect user privacy. The analysis shows that ACSMS achieves cross-chain swap without loss of CAV security privacy. The simulation results show that our method can realize multiple blockchain-based applications in VANETs