Parameters Identification for Simplified Yaw Model of Articulated Heavy Vehicle

2013 ◽  
Vol 765-767 ◽  
pp. 387-391 ◽  
Author(s):  
Zhi Gen Nie ◽  
Chang Fu Zong

In order to accurately characterize the lateral dynamic characteristics of articulated heavy vehicle, 3-dof simplified yaw model of articulated heavy vehicles is established and key parameters of models are identified by genetic algorithm. MAPs of key parameters, which the vehicle speed and steering wheel angle are independent variables for, are formed using the key identification parameters. Simulation study of dynamic state is carried out by the MAPs of key identification parameters and 3-dof simplified yaw model. That simulation result compared with Trucksim data indicates that key parameters can be accurately identified and the MAPs of key identification parameters satisfies the need of characterizing the actual state of vehicle.

2004 ◽  
Vol 127 (3) ◽  
pp. 406-414 ◽  
Author(s):  
Bo-Chiuan Chen ◽  
Huei Peng

A Time-To-Rollover (TTR) metric is proposed as the basis to assess rollover threat for an articulated heavy vehicle. The TTR metric accurately “counts-down” toward rollover regardless of vehicle speed and steering patterns, so that the level of rollover threat is accurately assessed. There are two conflicting requirements in the implementation of TTR. On the one hand, a model significantly faster than real-time is needed. On the other hand, the TTR predicted by this model needs to be accurate enough under all driving scenarios. An innovative approach is proposed in this paper to solve this dilemma and the design process is illustrated in an example. First, a simple yet reasonably accurate yaw∕roll model is identified. A Neural Network (NN) is then developed to mitigate the accuracy problem of this simple model. The NN takes the TTR generated by the simple model, vehicle roll angle, and change of roll angle to generate an enhanced NN-TTR index. The NN was trained and verified under a variety of driving patterns. It was found that an accurate TTR is achieved across all the driving scenarios we tested.


1999 ◽  
Author(s):  
Giuseppe Sammartino ◽  
Farid Amirouche ◽  
Zhen L. Chen ◽  
Ming L. Wang

Abstract Heavy Vehicles speeds and dynamic loads are critical factors to bridge’s structure fatigue and rapid deterioration. The proposed paper addresses the modeling and simulation of dynamic loads of heavy vehicles, such as trucks and buses, on bridges and the effects of their speed on frequency response. In light of the above analysis, this paper proposes a method on how to minimize the structural vibrational of the combined vehicle and bridge system using semi-active suspension control. The vehicle dynamic load is minimized through an optimization scheme to yield an impact force with negligible bridge lateral deflection. The dynamic coupling between the vehicle and bridge are studied by examining the modes that are most likely to be excited by the vehicle speed and the roughness of the bridge surface. The models consist of a bridge and a heavy vehicle. The bridge is modeled as continuos, lightly damped beam with different supports defined by the boundary conditions. The vehicle is a multi-degree of freedom (MDOF) system undergoing motion in one plane. The methods of solution consist of a simple supported beam that closely simulates the first three beam modes of the Kishwaukee Bridge in Rockford, Illinois. The surface of the bridge generates some random excitation that serves as input to the vehicle, this is commonly known as the roughness of the bridge surface. The heavy vehicle is moving from left to right of the simply supported beam. The system is analyzed and optimized by semi-active control algorithms. Close form numerical solution is obtained by a set of second order differential equations for the bridge-vehicle system. Experimental data obtained from the vibration testing of Kishwaukee Bridge (Illinois) were collected and validated with a FEM model. Only the first three beam modes were used due to the experimental limitations and the actual structural condition of the bridge. Using MATLAB a simulation is obtained by inputting the linear time-variant equations and optimizing the system. Simulations of bridge vertical motion under different dynamic load conditions were examined and the results of bridge structure response were analyzed by comparing the effects of passive versus semi-active suspension controls. The method shows effectively how we can reduce the dynamic load force magnitude and its frequency of impact. The latter is usually associated with structural damage caused to the bridge.


2021 ◽  
Vol 13 (11) ◽  
pp. 6337
Author(s):  
Nurzaki Ikhsan ◽  
Ahmad Saifizul ◽  
Rahizar Ramli

Heavy vehicles make up a relatively small percentage of traffic volume on Malaysian roads compared to other vehicle types. However, heavy vehicles have been reported to be involved in 30,000–40,000 accidents yearly and caused significantly more fatalities. Rollover accidents may also incur cargo damages and cause environmental or human disasters for vehicles that carry hazardous cargos if these contents are spilled. Thus, in this paper, a comprehensive study was conducted to investigate the effects of vehicle and road conditions on rollover of commercial heavy vehicles during cornering at curved road sections. Vehicle conditions include the heavy vehicle class (based on the axle number and vehicle type), speed and gross vehicle weight, while road conditions include the cornering radius and coefficient of friction values. In order to reduce the risks involved in usage of actual heavy vehicles in crash experiments, a simulation approach using a multi-body vehicle dynamic software was applied in this study, where the verified virtual heavy vehicle model was simulated and the output results were extracted and analyzed. The results showed that a maximum of 40% and a minimum of 23% from the total number of simulations resulted in an unsafe condition (indicated as failed) during the simulations. From the unsafe conditions, two types of rollover accidents could be identified, which were un-tripped and tripped rollovers. The heavy vehicle speed was also found to have a strong correlation to the lateral acceleration (to cause a rollover), followed by gross vehicle weight, coefficient of friction and cornering radius, respectively.


2020 ◽  
Vol 11 (1) ◽  
pp. 102-111
Author(s):  
Em Poh Ping ◽  
J. Hossen ◽  
Wong Eng Kiong

AbstractLane departure collisions have contributed to the traffic accidents that cause millions of injuries and tens of thousands of casualties per year worldwide. Due to vision-based lane departure warning limitation from environmental conditions that affecting system performance, a model-based vehicle dynamics framework is proposed for estimating the lane departure event by using vehicle dynamics responses. The model-based vehicle dynamics framework mainly consists of a mathematical representation of 9-degree of freedom system, which permitted to pitch, roll, and yaw as well as to move in lateral and longitudinal directions with each tire allowed to rotate on its axle axis. The proposed model-based vehicle dynamics framework is created with a ride model, Calspan tire model, handling model, slip angle, and longitudinal slip subsystems. The vehicle speed and steering wheel angle datasets are used as the input in vehicle dynamics simulation for predicting lane departure event. Among the simulated vehicle dynamic responses, the yaw acceleration response is observed to provide earlier insight in predicting the future lane departure event compared to other vehicle dynamics responses. The proposed model-based vehicle dynamics framework had shown the effectiveness in estimating lane departure using steering wheel angle and vehicle speed inputs.


Author(s):  
Parthkumar Patel ◽  
H.R. Varia

Safe, convenient and timely transportation of goods and passengers is necessary for development of nation. After independence road traffic is increased manifold in India. Modal share of freight transport is shifted from Railway to roadways in India. Road infrastructures continuously increased from past few decades but there is still need for new roads to be build and more than three forth of the roads having mixed traffic plying on it. The impact of freight vehicles on highway traffic is enormous as they are moving with slow speeds. Nature of traffic flow is dependent on various traffic parameters such as speed, density, volume and travel time etc. As per ideal situation these traffic parameters should remain intact, but it is greatly affected by presence of heavy vehicle in mixed traffic due to Svehicles plying on two lane roads. Heavy vehicles affect the traffic flow because of their length and size and acceleration/deceleration characteristics.  This study is aimed to analyse the impact of heavy vehicles on traffic parameters.


Author(s):  
C. C. Osadebe ◽  
H. A. Quadri

The prevalence of flexible pavement deterioration in the country has been adduced largely by highway researchers to trucks or heavy vehicles carrying much in excess of permitted legal limits. This study investigated levels of deterioration of Abuja-Kaduna-Kano road (Northern region) and Port Harcourt-Enugu road (Southern region) caused by heavy vehicles through a 14 day traffic counts conducted at 5 strategic points each in the Northern and Southern regions. Traffic data generated were analyzed with AASHTO Design Guidelines (1993) to evaluate Equivalent Single Axle Loads (ESALs) and Vehicle Damage effects on the road. The Traffic Volume, Average Daily Traffic (ADT), and Heavy Vehicle per day (HV/day) were estimated to be 2,063,977; 147,427; and 12,246 respectively in the Northern region, while in the Southern region they were estimated to be 750,381; 53,670; and 20,951 respectively. Motorcycles, Passenger cars, Mini-buses/Pick-ups, and Heavy vehicles constitute 18.7%, 49.7%, 23.3% and 8.31% of the total traffic volume respectively in the Northern region while in the South they constitute 4.6%, 30.1%, 26.2% and 39.1% respectively. ESALs were estimated according to AASHTO Design Guidelines in the Northern and Southern regions as 547,730 and 836,208 respectively. An average Load Equivalency Factors (LEFs) of 3.43 and 3.02 were estimated for each heavy vehicle plying the Northern and Southern roads respectively and this could explain some failures (alligator cracks, potholes, depressions, linear or longitudinal cracks along the centre line amongst others) inherent on the road.


2014 ◽  
Vol 8 (1) ◽  
pp. 292-296
Author(s):  
Zhi-Guo Zhao ◽  
Min Chen ◽  
Nan Chen ◽  
Yong-Bing Zhao ◽  
Xin Chen

The lateral security of heavy vehicle in deteriorative weather is one of the main causes of accidents of vehicles on roads. Road safety has become a subject of great concern to institutions of higher education and scientific research institutions. There are important theoretical and practical significances to explore applicable and effective lateral safety warning methods of heavy vehicles. One of the purposes of this paper is to provide a good theoretical basis for the core technology of heavy vehicle safety features for our country's independent research and development. Aiming at the issue of lateral security of heavy vehicle for road conditions in deteriorative weather, this paper constructs the framework of the lateral security pre-warning system of heavy vehicles based on cooperative vehicle infrastructure. Moreover, it establishes vehicle lateral security statics model through analysis of the force of the car in the slope with section bending and states the parameters of vehicles for no rollover. The side slip is indexed to calculate critical speed of vehicles in a bend. This paper also analyzes the influence of road friction coefficient, the road gradient and the turning radius on the lateral security of the vehicle with critical speed on the asphalt pavement with surface conditions ranging from wet, dry, snowing or icy. The calculation results show that the bad weather road conditions, road friction coefficient and turning radius have obvious influence on the lateral security critical speed. Experimental results indicate that the critical speed error warning is within 4% and it meets the design requirements.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jianzhong Cui ◽  
Hu Li ◽  
Dong Zhang ◽  
Yawen Xu ◽  
Fangwei Xie

Purpose The purpose of this study is to investigate the flexible dynamic characteristics about hydro-viscous drive providing meaningful insights into the credible speed-regulating behavior during the soft-start. Design/methodology/approach A comprehensive dynamic transmission model is proposed to investigate the effects of key parameters on the dynamic characteristics. To achieve a trade-off between the transmission efficiency and time proportion of hydrodynamic and mixed lubrication, a multi-objective optimization of friction pair system by genetic algorithm is presented to obtain the optimal combination of design parameters. Findings Decreasing the engagement pressure or the ratio of inner and outer radius, increasing the lubricating oil viscosity or the outer radius will result in the increase of time proportion of hydrodynamic and mixed lubrication, as well as the transmission efficiency and its maximum value. After optimization, main dynamic parameters including the oil film thickness, angular velocity of the driven disk, viscous torque and total torque show remarkable flexible transmission characteristics. Originality/value Both the dynamic transmission model and multi-objective optimization model are established to analyze the effects of main design parameters on the dynamic characteristics of hydro-viscous flexible drive.


2015 ◽  
pp. 1540-1566
Author(s):  
Sara Moridpour

Heavy vehicles have substantial impact on traffic flow particularly during heavy traffic conditions. Large amount of heavy vehicle lane changing manoeuvres may increase the number of traffic accidents and therefore reduce the freeway safety. Improving road capacity and enhancing traffic safety on freeways has been the motivation to establish heavy vehicle lane restriction strategies to reduce the interaction between heavy vehicles and passenger cars. In previous studies, different heavy vehicle lane restriction strategies have been evaluated using microscopic traffic simulation packages. Microscopic traffic simulation packages generally use a common model to estimate the lane changing of heavy vehicles and passenger cars. The common lane changing models ignore the differences exist in the lane changing behaviour of heavy vehicle and passenger car drivers. An exclusive fuzzy lane changing model for heavy vehicles is developed and presented in this chapter. This fuzzy model can increase the accuracy of simulation models in estimating the macroscopic and microscopic traffic characteristics. The results of this chapter shows that using an exclusive lane changing model for heavy vehicles, results in more reliable evaluation of lane restriction strategies.


2014 ◽  
Vol 1030-1032 ◽  
pp. 1537-1542 ◽  
Author(s):  
Li Qin Sun ◽  
Zhen Cui

Based on semi-active interconnected air suspension system full vehicle dynamic model, Hierarchical control strategy is used to design LIAS control system to improve vehicle riding comfort.The upper layer is mode judgements layer ,and the lower layer is interconnection condition control and damping condition control layer.Interconnection condition control rules are carried out by taking vehicle speed, steering wheel angle and vehicle roll angle as input parameters.On base of the model,simulation results show that vehicle riding comfort increases by 29.2% and 3.37% through using mixed SH-ADD control than that of SH and ADD control individually,and vehicle roll angle reduces effectively under double-lane condition by using sport mode control rules.


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