Rollover Prevention and Motion Planning for an Intelligent Heavy Truck

It is very necessary for an intelligent heavy truck to have the ability to prevent rollover independently.However,it was rarely considered in intelligent vehicle motion planning.To improve rollover stability,a motion planning strategy with autonomous anti rollover ability for an intelligent heavy truck is put forward in this paper.Considering the influence of unsprung mass in the front axle and the rear axle and the body roll stiffness on vehicle rollover stability,a rollover dynamics model is built for the intelligent heavy truck.From the model,a novel rollover index is derived to evaluate vehicle rollover risk accurately,and a model predictive control algorithm is applicated to design the motion planning strategy for the intelligent heavy truck,which integrates the vehicle rollover stability,the artificial potential field for the obstacle avoidance,the path tracking and vehicle dynamics constrains.Then,the optimal path is obtained to meet the requirements that the intelligent heavy truck can avoid obstacles and drive stably without rollover.In addition,three typical scenarios are designed to numerically simulate the dynamic performance of the intelligent heavy truck.The results show that the proposed motion planning strategy can avoid collisions and improve vehicle rollover stability effectively even under the worst driving scenarios.

Probabilistic Lane-Change Decision-Making and Planning for Autonomous Heavy Vehicles

To improve the safety and driving stability of the autonomous heavy truck, it is necessary to consider the differences of driving behavior and drivable trajectories between the heavy trucks and passenger cars. This study proposes a probabilistic decision-making and trajectory planning framework for the autonomous heavy trucks. Firstly, the driving decision process is divided into intention generation and feasibility evaluations, which are realized using the utility theory and risk assessment, respectively. Subsequently the driving decision is made and sent to the trajectory planning module. In order to reflect the greater risks of the truck to other surrounding vehicles, the aggressiveness index(AI) is proposed and quantified to infer the asymmetrical risk level of lane-change maneuver. In the planning stage, the lateral and roll dynamics stability domains are developed as the constraints to exclude the candidate trajectories that would cause vehicle instability. Finally, the simulation results are compared between the proposed model and the artificial potential filed model in the scenarios extracted from the naturalistic driving data. It is shown that the proposed framework can provide the human-like lane-change decisions and truck-friendly trajectories, and performs well in dynamic driving environments.

Active Noise Control of the Heavy Truck Interior Cab

In order to control the noise of the heavy truck interior cab effectively, the active noise control methods are employed. First, an interior noise field test for the heavy truck is performed, and frequencies of interior noise of this vehicle are analyzed. According to the spectrum analysis of acquired noise signal, it is found out that the main frequencies of interior noise are less than 800Hz. Then the least squares lattice （LSL） algorithm is used as signal processing algorithm of the controller and a closed-loop control DSP system, based on TMS 320VC5416, is developed. The residual signal at driver＇s ear is used as feedback signal. Lastly, the developed ANC system is loaded into the heavy truck cab, and controlling the noise at driver＇ s ear for that truck at different driving speeds is attempted. The noise control test results indicate that the cab interior noise is reduced averagely by 0.9 dBA at different driving speeds.

Numerical simulation of dynamic response of subgrade under moving heavy truck in cold regions

This paper reports on the dynamic response of highway subgmde under moving heavy Wuck in cold regions. Numerical simulations are performed in two stages. In the first stage, the moving heavy truck vibration, induced by mad roughness, is calculated through a three-dimensional dynamic interaction model of heavy tmckavement-subgrade, and the lime-histories of nodal loads on the top of the base are calculated through this model. In the second stage, a two-dimensional dynamic finite element model of the bgrade-ground system is formulated, using the calculated nodal loads from the first stage as input. The dynamic resporkse of the subgrade is validated by field measurements, and the effects of mack type, axle loading, running speed, and road roughness on the vertical dynamic slress in the unfrozen period and the spring thawing period are analyzed and discussed.

Investigation of the optimum differential gear ratio for real driving cycles by experiment design and genetic algorithm

Experiment statistical method and genetic algorithms based optimization method are used to obtain the optimum differential gear ratio for heavy truck that provides best fuel consumption when changing the working condition that affects its torque and speed range. The aim of the study is to obtain the optimum differential gear ratio with fast and accurate optimization calculation without affecting drivability characteristics of the vehicle according to certain driving cycles that represent the new working conditions of the truck. The study is carried on a mining dump truck YT3621 with 9 for- ward shift manual transmission. Two loading conditions, no load and 40 t, and four on road real driving cycles have been discussed. The truck powertrain is modeled using GT-drive, and DOE -post processing tool of the GT-suite is used for DOE analysis and genetic algorithm optimization.

Dynamic response of precast segmental bridge columns under heavy truck impact

Considering the wide application of precast segmental bridge columns(PSBCs)in engineering practice,impact-resistant performance has gained significant attention.However,few studies have focused on PSBCs subjected to high-energy impacts caused by heavy truck collisions.Therefore,the behavior of PSBCs under a heavy truck impact was investigated in this study using high-fidelity finite element(FE)models.The detailed FE modeling methods of the PSBCs and heavy trucks were validated against experimental tests.The validated modeling methods were employed to simulate collisions between PSBCs and heavy trucks.The simulation results demonstrated that the engine and cargo caused two major peak impact forces during collision.Subsequently,the impact force,failure mode,displacement,and internal force of the PSBCs under heavy truck impacts were scrutinized.An extensive study was performed to assess the influence of the section size,truck weight,impact velocity,and number of precast segments on the impact responses.The truck weight was found to have a minor effect on the engine impact force.Damage was found to be localized at the bottom of the three segments,with the top remaining primarily undamaged.This parametric study demonstrated that larger cross-sections may be a preferred option to protect PSBCs against the impact of heavy trucks.

Analysis of coast-by noise of heavy truck tires

Heavy truck tires are one of ihe rnam sources of road traffic noise. However, the mecha- nism and plopagation of the noise generated by these tires have not been systematically investigated 7o determine the noise of heavy truck tires with different structures and patterns, and to analyze the coraelation between the indoor tire noise and coast-by tire noise, an integrated tire indoor noise test and a coast-by noise test were designed and successfully implemented. The indoor test was conducted on a drum inside a semi- anechoic chamber to simultaneously measure the near field and far field noise of the tires. The outdoor measurements were carried out using a coast-by test on the new ISO 10844 surface. A formula for quantitative analysis with appropriate corrections was developed to analyze the data with reasonable errors, which can be used to predict the coast-by noise through the indool tire noise test accurately and effectively. The analysis shows that when trying to build the relationship between indoor and outdoor heavy truck tire noise, care should be taken to differentiate the tires with a load capacity index in excess of 121 and without any dual fitting indication from ordinary tires, due to the specified test procedure.

Strategic Issues For Prospering China Heavy Truck Industry

As an important segment in auto industry, heavy duty truck industry plays a special strategy role in the national economy and social development. With the continuous, fast and healthy development of the national economy, the importance ofheavy duty truck has become more and more tangible. 1. The improvement of highway conditions and the construction of expressway will promote the adjustment of national transportation structure. Highway transportation trends towards long

The Up-rising of the Inner Mongolia's Heavy Truck Base

During the "8th Five-Year Plan" of China, Baotou North Heavy Truck Limited Liability Company and Baotou North-Benz Heavy Truck Limited Liability Company growing out of two big military plants——No. 1 Machinery Plant and the No. 2 Machinery Plant were founded. They introduced the technologies and