共查询到20条相似文献,搜索用时 15 毫秒
1.
Allan I. Krauter 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1973,2(2):61-91
This paper describes a study of anti-skid braking and the effects of such braking on the handling behavior and braking performance of a tractor-semitrailer truck. The truck, represented by a digital computer model having fourteen degrees of freedom, is taken to be in a cornering maneuver that involves braking and driver steering. Conventional braking or one of three types of anti-skid braking is used in the maneuver. The results show that the effects of anti-skid braking on the handling behavior and braking performance of the truck are beneficial. The results also show that the behavior of the wheels and the handling behavior and braking performance of the truck depend on the type of anti-skid braking used. 相似文献
2.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(4):203-231
SUMMARY This paper is concerned with the braking performance and the handling behavior of the tractor-semitrailer truck under optimal braking. Optimal control theory is used in order to deal with the problem and a combination of the steepest descent method and the Davidon Fletcher Powell method is used to solve it numerically. Results for some chosen braking maneuvers are obtained for a nonlinear truck model which has 14 degrees of freedom. These results show that, for the chosen maneuvers an idealized anti-skid braking is close to being optimal in the sense defined in this paper. Implementation of an idealized anti-skid braking on the tractor-semitrailer truck, however, may be not desirable. 相似文献
3.
Anton Th. Van Zanten Allan I. Krauter 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1978,7(4):203-231
This paper is concerned with the braking performance and the handling behavior of the tractor-semitrailer truck under optimal braking. Optimal control theory is used in order to deal with the problem and a combination of the steepest descent method and the Davidon Fletcher Powell method is used to solve it numerically. Results for some chosen braking maneuvers are obtained for a nonlinear truck model which has 14 degrees of freedom. These results show that, for the chosen maneuvers an idealized anti-skid braking is close to being optimal in the sense defined in this paper. Implementation of an idealized anti-skid braking on the tractor-semitrailer truck, however, may be not desirable. 相似文献
4.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(2):123-160
SUMMARY The nonlinear equations of motion are derived for a tractor-semitrailer truck where both the itractor and the semitrailer yaw, pitch, roll, and translate. Special emphasis is placed on the constraints imposed by the fifth wheel on the vehicle motion. In particular, the effects of two proposed fifth wheel design changes on the jackknifing behavior of a vehicle in a turning, braking maneuver are studied. The results demonstrate that the tendency of the vehicle to jackknife can be reduced with a geometric modification of the fifth wheel. 相似文献
5.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(4-5):401-412
SUMMARY A study on effective use of rear braking force to improve a brake performance and vehicle dynamics are carried out. On a ordinary condition, the rear braking force could be more increased to a conventional braking force distribution. Based on this thought, the brake performances are estimated. The results show the effects not only improve the brake performance but also reduce a pitching at braking and moderate a vehicle OS behavior in a turn during braking. These are verified by experimental test vehicle equipped with a rear braking force control system. 相似文献
6.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(4-5):413-426
SUMMARY This paper describes the feasibility of improving the braking performance of a commercial vehicle by using an electronic braking system. An electronic braking system enables the braking force at each wheel to be independently controlled. Braking force distribution control makes the braking force at each wheel proportional to each wheel's load. Results of computer simulation and vehicle test showed that the proposed control laws can eliminate the effects of a laden condition on the braking distance and can increase the degree of deceleration at which wheel lock occurs, resulting in improved vehicle attitude stability during a critical maneuver. 相似文献
7.
William E. Tobler Allan I. Krauter 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1972,1(2):123-160
The nonlinear equations of motion are derived for a tractor-semitrailer truck where both the itractor and the semitrailer yaw, pitch, roll, and translate. Special emphasis is placed on the constraints imposed by the fifth wheel on the vehicle motion. In particular, the effects of two proposed fifth wheel design changes on the jackknifing behavior of a vehicle in a turning, braking maneuver are studied. The results demonstrate that the tendency of the vehicle to jackknife can be reduced with a geometric modification of the fifth wheel. 相似文献
8.
文章针对某重卡6×4自卸车出现辅助制动效果不良的现象,结合此车型对排气辅助制动器参数进行理论校核计算,发现按照理论参数进行匹配设计并不能有效地提高排气辅助制动性能:同时与市场上反映使用效果较好的同等竞品车型进行对比分析,找出导致该重型自卸车排气辅助制动效果不良的主要原因,并对该自卸车排气辅助制动系统进行优化;通过试验验证表明,改进后的辅助制动性能得到明显提升,并优于同等竞品车型。 相似文献
9.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(5-6):305-324
SUMMARY This paper presents a review of theoretical and experimental works relative to the handling performance of commercial vehicle combinations. A commercial vehicle combination (road train) is defined as a tractor unit and an arbitrary number of trailers. The review contains literature corresponding the most widely used types of trains: tractor-semitrailer, truck-trailer and tractor-semitrailer-semitrailer (doubles). The vehicle dynamic performance has been investigated taking into consideration the following features: directional performance, roll dynamics, braking performance and combined braking and directional performance. With the aim of evaluating the present state of research activities in the field of lateral dynamics of articulated commercial vehicles, the author has compiled some 250 references. 相似文献
10.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(5-6):357-370
SUMMARY An integrated control system of active rear wheel steering (4WS) and direct yaw moment control (DYC) is presented in this paper. Because of the tire nonlinearity that is mainly due to the saturation of cornering forces, vehicle handling performance is improved but limited to a certain extent only by steering control. Direct yaw moment control using braking and/or driving forces is effective not only in linear but also nonlinear ranges of tire friction circle. The proposed control system is a model matching controller which makes the vehicle follow the desired dynamic model by the state feedback of both yaw rate and side slip angle. Various computer simulations are carried out and show that vehicle handling performance is much improved by the integrated control system. 相似文献
11.
12.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(3):149-180
SUMMARY In this paper a simulation model of tractor-semitrailers suitable for design and performance analysis of anti-lock systems is presented. The model is used to evaluate the effects of various methods of prediction and reselection of the anti-lock system on the braking performance of tractor-semitrailers. The characteristics and the equivalent control logic of a commercially available anti-lock system are examined and its deficiencies are identified. To rectify these deficiencies, improved methods of prediction and reselection are proposed. A comparison of the slip characteristics and braking effectiveness between the proposed and the commercially available systems is made. The effects of various types of control logic on the steerability and directional stability of tractor-semitrailers and on the air consumption of the brake systems will be examined in a separate paper. 相似文献
13.
There are basically two methods to control yaw moment which is the most efficient way to improve vehicle stability and handling.
The first method is indirect yaw moment control, which works based on control of the lateral tire force through steering angle
control. It is mainly known as active steering control (ASC). Nowadays, the most practical approach to steering control is
active front steering (AFS). The other method is direct yaw moment control (DYC), in which an unequal distribution of longitudinal
tire forces (mainly braking forces) produces a compensating external yaw moment. It is well known that the AFS performance
is limited in the non-linear vehicle handling region. On the other hand, in spite of a good performance of DYC in both the
linear and non-linear vehicle handling regions, continued DYC activation could lead to uncomfortable driving conditions and
an increase in the stopping distance in the case of emergency braking. It is recommended that DYC be used only in high-g critical
maneuvers. In this paper, an integrated fuzzy/optimal AFS/DYC controller has been designed. The control system includes five
individual optimal LQR control strategies; each one, has been designed for a specific driving condition. The strategies can
cover low, medium, and high lateral acceleration maneuvers on high-μ or low-μ roads. A fuzzy blending logic also has been utilized to mange each LQR control strategy contribution level in the final control
action. The simulation results show the advantages of the proposed control system over the individual AFS or DYC controllers. 相似文献
14.
15.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(5-6):457-476
SUMMARY The computer modelling of vehicle ride and handling has been widely reported, but often only one or other of these functions is considered. This is especially true in the design of active suspension controllers, where the effects that improvements in the performance of one aspect have on the other are often not presented. This paper initially describes a combined ride and handling model for a large executive saloon fitted with a slow-active suspension. Separately derived ride and roll control strategies are combined and the effects on both ride and handling considered for straight running and various handling man?uvres on rough roads. The results are compared to the original passively suspended vehicle and the effect of running each strategy separately. 相似文献
16.
T. Morita T. Matsukawa 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1995,24(4):401-412
A study on effective use of rear braking force to improve a brake performance and vehicle dynamics are carried out. On a ordinary condition, the rear braking force could be more increased to a conventional braking force distribution. Based on this thought, the brake performances are estimated. The results show the effects not only improve the brake performance but also reduce a pitching at braking and moderate a vehicle OS behavior in a turn during braking. These are verified by experimental test vehicle equipped with a rear braking force control system. 相似文献
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18.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(10):1494-1529
ABSTRACTIn this paper, a coordinated control strategy is proposed to provide an effective improvement in handling stability of the vehicle, safety, and comfortable ride for passengers. This control strategy is based on the coordination among active steering, differential braking, and active suspension systems. Two families of controllers are used for this purpose, which are the high order sliding mode and the backstepping controllers. The control strategy was tested on a full nonlinear vehicle model in the environment of MATLAB/Simulink. Rollover avoidance and yaw stability control constraints have been considered. The control system mainly focuses on yaw stability control. When rollover risk is detected, the proposed strategy controls the roll dynamics to decrease rollover propensity. Simulation results for two different critical driving scenarios, the first one is a double lane change and the other one is a J-turn manoeuvre, show the effectiveness of the coordination strategy in stabilising the vehicle, enhancing handling and reducing rollover propensity. 相似文献
19.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(11):1601-1620
ABSTRACTTires are used by the customers during several tens of thousands of kilometres, and before their replacement, the driver will encounter a continuous variation of tread depth due to the tire wearing. Although the wet braking labelling demonstrates the performance of the tire in the new stage, it is known that the wet traction evolves with tire wear. In this paper, an in-depth comparison of the wet grip performance of new and worn tires will be conducted, based on the regulatory wet braking test. For this purpose, we propose an original approach to analyse braking test results, which allows breaking down and quantifying the relative importance of the mechanisms involved during this test. This study demonstrates that two main mechanisms are taking place during the entire test: rubber friction and hydroplaning mechanisms. The µ value obtained at low speeds reflects the friction potential of the tested tires while the decline of performance at higher speeds is attributed to hydroplaning mechanisms. This analysis is conducted on numerous tires and demonstrates that current regulatory test applied on new tires is focussing mainly on the rubber friction mechanism. The same test applied on worn tires exhibits both rubber friction and hydroplaning mechanisms. The mechanisms decomposition shows that the source of the performance decline from new to worn status varies greatly, some tires having most of their performance loss due to hydroplaning, some others due to rubber friction drop. 相似文献
20.
Impact of Liquid Load Shift on the Braking Characteristics of Partially Filled Tank Vehicles 总被引:1,自引:0,他引:1
R. Ranganathan Y. S. Yang 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1996,26(3):223-240
Braking characteristics of a tractor-tank-semitrailer vehicle is investigated by incorporating the influence of liquid load shift occurring within the partially filled tank. The tank vehicle model is developed by integrating a steady state model of a partially filled tank and a pitch plane model of the vehicle. The liquid load shift occurring in the pitch plane of the vehicle during a braking maneuver is characterized using the change in the gradient of the free surface of liquid and the corresponding shift in the center of gravity of the fluid bulk. The change in normal load on the various axles of the vehicle during the maneuver is then computed to analyze the braking behavior of the partially filled tank vehicle. The braking characteristics of the tank vehicle are then compared to those of an equivalent rigid cargo vehicle in order to study the impact of liquid load shift. Influence of various vehicle and tank design parameters on the braking behavior and wheel lock-up condition is also investigated for typical braking maneuvers. 相似文献