Objective Analysis of the Stability of an Extralegal Weight Tractor-Trailer Combination during a Rapid Air Loss Event

2014 ◽  
Vol 42 (1) ◽  
pp. 35-56
Author(s):  
Jeffery Anderson ◽  
Ryan Pawlowski

ABSTRACT In the California Transportation Permits Manual, the minimum overall tire-to-tire axle width (overall width) of a vehicle in the extralegal weight configuration is 2.44 m. Commercial truck tractor and trailer tandem 1.82-m-wide axles fitted with new-generation wide base single (NGWBS) tires measure 2.34 m in overall axle width; thus, they are not compliant with the current California Department of Transportation requirement. Because of the growing application of NGWBS tires in the market, it is important to understand the vehicle stability characteristics of a tractor-semitrailer fitted with both dual and NGWBS tire configurations. In this research, a comparison of dual to NGWBS with both a 50.8-m outset wheel and a 25.4-mm outset wheel is presented. A rapid air loss (RAL) event was initiated to represent a severe scenario in each of the three following maneuvers: straight line, steady-state curve, and lane change. The data were evaluated, and differences between NGWBS and dual tire–fitted vehicles were compared. While a tire RAL event can be perceived as a dramatic event, previous studies and driver-training events have shown that such an RAL event is manageable. The conclusion of this work is that an RAL event with NGWBS tires is as manageable as a dual tire–fitted vehicle and does not make the system unstable.

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Shu Wang ◽  
Xuan Zhao ◽  
Qiang Yu

Vehicle stability control should accurately interpret the driving intention and ensure that the actual state of the vehicle is as consistent as possible with the desired state. This paper proposes a vehicle stability control strategy, which is based on recognition of the driver’s turning intention, for a dual-motor drive electric vehicle. A hybrid model consisting of Gaussian mixture hidden Markov (GHMM) and Generalized Growing and Pruning RBF (GGAP-RBF) neural network is constructed to recognize the driver turning intention in real time. The turning urgency coefficient, which is computed on the basis of the recognition results, is used to establish a modified reference model for vehicle stability control. Then, the upper controller of the vehicle stability control system is constructed using the linear model predictive control theory. The minimum of the quadratic sum of the working load rate of the vehicle tire is taken as the optimization objective. The tire-road adhesion condition, performance of the motor and braking system, and state of the motor are taken as constraints. In addition, a lower controller is established for the vehicle stability control system, with the task of optimizing the allocation of additional yaw moment. Finally, vehicle tests were carried out by conducting double-lane change and single-lane change experiments on a platform for dual-motor drive electric vehicles by using the virtual controller of the A&D5435 hardware. The results show that the stability control system functions appropriately using this control strategy and effectively improves the stability of the vehicle.


Author(s):  
Gary Lippner ◽  
John Johnston ◽  
Suzanne Combs ◽  
Kimberly Walter ◽  
David Marx

2018 ◽  
Vol 8 (8) ◽  
pp. 1257 ◽  
Author(s):  
Tianqi Yang ◽  
Weimin Zhang ◽  
Xuechao Chen ◽  
Zhangguo Yu ◽  
Libo Meng ◽  
...  

The most important feature of this paper is to transform the complex motion of robot turning into a simple translational motion, thus simplifying the dynamic model. Compared with the method that generates a center of mass (COM) trajectory directly by the inverted pendulum model, this method is more precise. The non-inertial reference is introduced in the turning walk. This method can translate the turning walk into a straight-line walk when the inertial forces act on the robot. The dynamics of the robot model, called linear inverted pendulum (LIP), are changed and improved dynamics are derived to make them apply to the turning walk model. Then, we expend the new LIP model and control the zero moment point (ZMP) to guarantee the stability of the unstable parts of this model in order to generate a stable COM trajectory. We present simulation results for the improved LIP dynamics and verify the stability of the robot turning.


Author(s):  
Naser Esmaeili ◽  
Reza Kazemi ◽  
S Hamed Tabatabaei Oreh

Today, use of articulated long vehicles is surging. The advantages of using large articulated vehicles are that fewer drivers are used and fuel consumption decreases significantly. The major problem of these vehicles is inappropriate lateral performance at high speed. The articulated long vehicle discussed in this article consists of tractor and two semi-trailer units that widely used to carry goods. The main purpose of this article is to design an adaptive sliding mode controller that is resistant to changing the load of trailers and measuring the noise of the sensors. Control variables are considered as yaw rate and lateral velocity of tractor and also first and second articulation angles. These four variables are regulated by steering the axles of the articulated vehicle. In this article after developing and verifying the dynamic model, a new adaptive sliding mode controller is designed on the basis of a nonlinear model. This new adaptive sliding mode controller steers the axles of the tractor and trailers through estimation of mass and moment of inertia of the trailers to maintain the stability of the vehicle. An articulated vehicle has been exposed to a lane change maneuver based on the trailer load in three different modes (low, medium and high load) and on a dry and wet road. Simulation results demonstrate the efficiency of this controller to maintain the stability of this articulated vehicle in a low-speed steep steer and high-speed lane change maneuvers. Finally, the robustness of this controller has been shown in the presence of measurement noise of the sensors. In fact, the main innovation of this article is in the designing of an adaptive sliding mode controller, which by changing the load of the trailers, in high-speed and low-speed maneuvers and in dry and wet roads, has the best performance compared to conventional sliding mode and linear controllers.


Author(s):  
Mobashwir Khan ◽  
Anurag Komanduri ◽  
Kalin Pacheco ◽  
Cemal Ayvalik ◽  
Kimon Proussaloglou ◽  
...  

This paper describes the findings from the California Vehicle Inventory and Use Survey (CA-VIUS) which was administered between June 2016 and January 2018 and obtained data from a total of 11,118 fleets and 14,790 trucks. The surveys were segmented by registration, geography, vehicle type, and vehicle age, and the data collection effort exceeded sampling targets across almost all segments. The CA-VIUS is the largest statewide commercial vehicle data collection effort in the United States and will replace the 2002 National VIUS in transportation planning and emissions studies throughout California. Currently, the wealth of information provided by the survey is supporting the development of the California Statewide Freight Forecasting Model which is a fine-grained behavioral freight model. This model will allow California Department of Transportation and its partners to make more informed infrastructure and operational investment decisions. The CA-VIUS data will also be useful for researchers and practitioners hoping to understand the impacts and benefits of commercial vehicle movements on air quality, economic activity, safety, and vehicle usage. This paper documents key sampling and survey approaches, but mainly focuses on the key findings observed in the survey. This is a practical paper geared towards practitioners who are seeking to analyze a new VIUS survey and those who wish to implement one of their own.


Robotics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 96
Author(s):  
Quang Huan Luong ◽  
Jeremy Jong ◽  
Yusuke Sugahara ◽  
Daisuke Matsuura ◽  
Yukio Takeda

A new generation electric high-speed train called Aerotrain has levitation wings and levitates under Wing-in-Ground (WIG) effect along a U-shaped guideway. The previous study found that lacking knowledge of the design makes the prototype unable to regain stability when losing control. In this paper, the nonlinear three-dimensional dynamic model of the Aerotrain based on the rigid body model has been developed to investigate the relationship between the vehicle body design and its stability. Based on the dynamic model, this paper considered an Aerotrain with a horizontal tail and a vertical tail. To evaluate the stability, the location and area of these tails were parameterized. The effects of these parameters on the longitudinal and directional stability have been investigated to show that: the horizontal tail gives its best performance if the tail area is a function of the tail location; the larger vertical tail area and (or) the farther vertical tail location will give better directional stability. As for the lateral stability, a dihedral front levitation wing design was investigated. This design did not show its effectiveness, therefore a control system is needed. The obtained results are useful for the optimization studies on Aerotrain design as well as developing experimental prototypes.


2019 ◽  
Vol 272 ◽  
pp. 01024 ◽  
Author(s):  
Feng YU ◽  
Jun XIE

Eight degrees of freedom vehicle model was established. Using the method of fuzzy control, the ABS control algorithm was designed based on slip ratio. Simulation analysis was done at speed of 15m/s, 20m/s, 25m/s under turning braking. The results show that the vehicle braking performance and vehicle stability at middle or low speed was improved by using the ABS controller, but qualitative analysis shows that phenomenon of vehicle instability was appeared at high-speed conditions. The turning braking stability under ABS controller was judged quantificationally by the stability judging formula. The results show that the requirements of stability control could not meet with only Anti-lock Braking System.


2003 ◽  
Vol 1819 (1) ◽  
pp. 231-236 ◽  
Author(s):  
Stephen H. Ford ◽  
Eugene C. Calvert

Mendocino County is a large rural county in northern California with more than 1,000 centerline miles of county-maintained roads. The terrain is mountainous, with a few small inland valleys. During the 1990s, the Mendocino County Department of Transportation developed a program of road system traffic safety reviews to improve signing and markings on the arterials and collectors in the system. The effectiveness of the program was measured by comparing accident data for the reviewed roads with data for roads not included in, or influenced by, the reviews. To control for different groups of factors, two sets of control roads were selected—county-maintained roads not reviewed and state highways within the county. Over two consecutive 3-year review cycles, the number of accidents on the reviewed roads fell by 42.1%, while on the county-maintained roads not reviewed they increased by 26.5%, and on the state highways they fell by 3.3%. The total cost to conduct the reviews and implement the recommended changes was $ 79,300. The accident histories of the control roads were used to define the limits of the range of probable benefits. On the basis of average accident costs provided by the California Department of Transportation, calculated savings ranged from $ 12.58 million to $23.73 million, yielding a costs-to-benefits ratio between 1:159 and 1:299. The county is expanding the road system traffic safety review program to cover its entire maintained road system.


Author(s):  
Jacob S. Duane ◽  
Joe A. Palen ◽  
Fidelis O. Eke ◽  
Harry H. Cheng

The California Department of Transportation, like many such departments in the United States, is working on developing a new family of electronic sensing devices for the purpose of monitoring certain characteristics of road vehicles as they move along the highway. The devices currently under development are to be located overhead individual highway traffic lanes, from where they can have a clear “view” of ground vehicles. In order to deploy these devices, there is a need to develop the capability to safely and efficiently mount them above highway traffic lanes, using existing overhead bridges and sign structures as support structures. This paper presents a technical study of a universal support platform for these devices. The study discusses such issues as mobility, reliability, and resistance to environmental and other hazards. Results of tests conducted on a prototype are also presented.


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