Simulation Study on Tractor’s Same-Rut-Steering Mechanism

2011 ◽  
Vol 338 ◽  
pp. 236-240
Author(s):  
Ren Cai Zhao ◽  
Xu Ma ◽  
Long Qi ◽  
Rui Chuan Li

When tractor steers in the same rut, it can not only improve its flexibility in steering, but also reduce soil compaction and crop rolling. In this paper , the concept of tractor steering in the same rut was proposed on the basis of four-wheel-steering (4WS) theory, and the angle relationship between front wheel and rear wheel, which can achieve the same-rut-steering, was established. A three dimensional parameterized model of tractor’s same-rut-steering mechanism was established by the Pro/E software, and its running tracks were simulated in the ADAMS environment. Simulation results show that the same-rut-steering accuracy was affected to some extent when tractor’s speed or steering wheel deflection rate was changed. At last, methods for improving the same-rut-steering accuracy were put forward.

2013 ◽  
Vol 404 ◽  
pp. 244-249
Author(s):  
Rui Wang ◽  
Hao Zhang ◽  
Xian Sheng Li ◽  
Xue Lian Zheng ◽  
Yuan Yuan Ren

By establishing bus simplify coordinate system model and equivalent mechanical model, inertial forces and external forces are analyzed through vehicle lateral movement and vehicle's yaw motion and roll motion. Three degrees of freedom linear motion equation of vehicle is established taking into account lateral motion, yawing movement and rolling motion of vehicle and it can be solved by using method of state space equation. Vehicle dynamic characteristics are analyzed by using this method and programming with Matlab. Vehicle in steering wheel angle step response is analyzed under the conditions of different tire wheel cornering stiffness, moment of inertia, height of center of mass. The results show that increasing rear wheel cornering stiffness, reducing front wheel cornering stiffness and center of mass height, which can effectively improve stability of vehicle. Simulation results provide a theoretical basis and reference for the selection and design of vehicle.


Author(s):  
C. S. Nanda Kumar ◽  
Shankar C. Subramanian

Regenerative braking is applied only at the driven wheels in electric and hybrid vehicles. The presence of brake force only at the driven wheels reduces the lateral traction limit of the corresponding tires. This impacts the vehicle lateral response, particularly while applying the regenerative brake in a turn. In this paper, a detailed study was made on the impact of regenerative brake on the vehicle lateral response in front wheel drive and rear wheel drive configurations on dry and wet asphalt road surfaces. Simulations were done considering a typical set of vehicle parameters with the IPG CarMaker® software for different drive conditions and braking configurations along the same reference track. The steering wheel angle, yaw rate, lateral acceleration, vehicle slip angle, and tire forces were obtained. Further, they were compared against the conventional all wheel friction brake configuration. The regenerative braking configuration that had the most impact on vehicle lateral response was analyzed and response variations were quantified.


2020 ◽  
Vol 10 (10) ◽  
pp. 3537
Author(s):  
Bin Deng ◽  
Han Zhao ◽  
Ke Shao ◽  
Weihan Li ◽  
Andong Yin

The synchronization error of the left and right steering-wheel-angles and the disturbances rejection of the synchronization controller are of great significance for the active rear axle independent steering (ARIS) system under complex driving conditions and uncertain disturbances. In order to reduce synchronization error, a novel hierarchical synchronization control strategy based on virtual synchronization control and linear active disturbance rejection control (LADRC) is proposed. The upper controller adopts the virtual synchronization controller based on the dynamic model of the virtual rear axle steering mechanism to reduce the synchronization error between the rear wheel steering angles of the ARIS system; the lower controller is designed based on an LADRC algorithm to realize an accurate tracking control of the steering angle for each wheels. Experiments based on a prototype vehicle are conducted to prove that the proposed hierarchical synchronization control strategy for the ARIS system can improve the control accuracy significantly and has the properties of better disturbances rejection and stronger robustness.


Author(s):  
Yoshihiro Takita ◽  
Date Hisashi

This paper proposes an SSM (Sensor Steering Mechanism) for a lateral guided vehicle with an articulated body. Authors demonstrated a simple lateral guiding method SSM for front wheel steer type, the reverse phase four-wheel steer type and rear wheel steer type vehicles. SSM presents a stable lateral guiding performance for automated vehicle that following a straight and curved path created by a guideway. This paper proposes a simplified SSM to remove the following servo system for a rotating camera. The simplified SSM is applied to 1/25 scale articulated dump truck that was developed and discussed in the previous paper. The stability of the simplified SSM is discussed. Experimental and simulation results show stable movement and performance of the proposed method.


2014 ◽  
Vol 607 ◽  
pp. 604-607 ◽  
Author(s):  
Ling Zhao

Considering the influence of wheel vertical load transfer and Steering angle, the paper establishes a dynamic model of 7 degrees freedom for vehicle under Braking in Turn Condition. Based on this model, wheel lock braking and ABS braking were researched and simulated. The simulation results show directly that first lock of front wheel loses vehicle steering performance, first lock the rear wheel sideslips, ABS braking can prevent loss of vehicle steering performance and sideslip, but slightly long braking distance.


2013 ◽  
Vol 302 ◽  
pp. 486-489
Author(s):  
Chong Jie Leng ◽  
Hui Yu Xiang ◽  
Xiao Zhuang Zhou ◽  
Jia Jun Huang

This paper utilized an intelligent vehicle model for the “Freescale” Cup National College Students' Intelligent Vehicle competition as the main study object. Under the prerequisite of adopting the same control procedures and algorithms, the mechanical structures and its parameters of the model vehicle which influence the running performance, such as front wheel alignment, steering mechanism and rear wheel deceleration mechanism are optimally designed and adjusted .It has been proved that the scheme induced the model vehicle driving fast and stable on the path-complex track and thus to achieve reasonable effects.


Author(s):  
Giuseppe Catania ◽  
Luca Leonelli ◽  
Nicolò Mancinelli

The chatter phenomenon, appearing during high speed cornering maneuvers performed by racing motorcycles, consists of a self-excited vertical oscillation of both the front and rear unsprung masses in the range of frequency between 17 and 22 Hz. The suspensions are not generally able to dampen the above vibrations which start from the rear wheel and suddenly propagate to the front wheel during the corner entry phase, making the vehicle’s handling unpredictable and, ultimately, weakening the overall performance, that is the lap time. It is not clear which is the determining factor causing this phenomenon. Therefore, numerical simulation on a three dimensional, multibody motorcycle model is proposed, taking into account the effects of the major parameters involved, in order to highlight which of them takes part in the vibration. Accurate models for tire and drivetrain have been developed, making it possible to consider tire carcass deformability, chain transmission in both traction and braking states, full drivetrain inertia and anti-hop clutch effect. A critical maneuver experimentally measured on the race track is analyzed. The modal response of the linearized system is evaluated for several configurations extracted from the maneuver. The above maneuver is then simulated with the model, showing the actual vibration uprising. A critical discussion of the possible physical interpretations of the phenomenon is given.


Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 696
Author(s):  
Abdolmajid Moinfar ◽  
Gholamhossein Shahgholi ◽  
Yousef Abbaspour-Gilandeh ◽  
Israel Herrera-Miranda ◽  
José Luis Hernández-Hernández ◽  
...  

To determine the effect of the tractor driving system type on the soil compaction and soil behavior a series of tests was conducted using Goldoni 240 tractor with a power rate of 30.8 kW and included four similar tires at three different driving systems (4WD, rear-wheel drive (RWD) and front-wheel drive (FWD)). To evaluate these systems’ effects on soil compaction, tests were conducted at three soil moisture contents (10, 15 and 20% d.b.), three tire inflation pressures (170, 200 and 230 kPa), and three tractor speeds (1.26, 3.96 and 6.78 km/h). Soil bulk density was measured at three average depths of 20, 30 and 40 cm. To evaluate soil compaction, cylindrical cores were used and to assess soil behavior during this process, the soil displacement in a three coordinate system was measured using three displacement transducers. It was found that the 4WD system created the least bulk density of 1155 kg/m3, while the FWD system led to the highest density of 1241 kg/m3. Maximum vertical soil compression of 55 mm occurred for the FWD system and it declined to 43 and 36 mm in RWD and 4WD systems, respectively. Soil displacement in the horizontal and lateral directions was larger for the FWD system in comparison to the other systems. With increment of speed and depth soil compaction decreased. Minimum bulk density of 1109 kg/m3 was occurred at velocity of 6.78 Km/h using the 4WD system, also with this system at the depth 40 cm density was 1127 kg/m3. While at velocity of 1.26 Km/h and depth of 20 cm soil density was 1190 kg/m3.


Author(s):  
Mr. Sharan L Pais ◽  
Manoj Kumar M ◽  
Namratha ◽  
Mayoori K Bhat ◽  
Vibha Mohan

The Shrimp rover is highly suitable for planetary exploration missions because of its unconventional wheel order, in-built passive adaptability and good ability to climb obstacles. It is a spatial multi-body system and a multi-variable, multi-parameter coupled non-linear system. Thus, kinematic and dynamic analyses for such systems are complex and time consuming. Long-range robotic missions for Martian exploration imply a high degree of autonomy. The most advanced locomotion concepts are based on wheels or caterpillars (e.g. Sojourner, NASA or Nanokhod, ESA). These rovers have clear advantages regarding power efficiency and complexity if compared with walking robots. However, they still have quite limited climbing abilities. Typically they can only overcome obstacle smaller than their wheel size. In this paper we present Shrimp, an innovative long range rover architecture with 6 motorized wheels. Using a rhombus configuration, the rover has a steering wheel in both, the front and the rear, and two wheels arranged on a bogie on each side. The front wheel has a spring suspension to guarantee optimal ground contact of all wheels at any time. The steering of the rover is realized by synchronizing the steering of the front and rear wheel and the speed difference of the bogie wheels. This allows for high precision maneuvers and even turning on the spot with minimum slip. The use of parallel articulations for the front wheel and the bogies enables to set a virtual centre of rotation at the level of the wheel axis while maintaining a high ground clearance. This insures maximum stability and climbing abilities even for relatively low friction coefficients between the wheel and the ground. This rover is able to passively overcome unstructured obstacles of up to two times its wheel diameter. With this high mobility, this architecture is the perfect candidate for long range planetary missions.


Author(s):  
Chenqi Zhu

In order to improve the guiding accuracy in intercepting the hypersonic vehicle, this article presents a finite-time guidance law based on the observer and head-pursuit theory. First, based on a two-dimensional model between the interceptor and target, this study applies the fast power reaching law to head-pursuit guidance law so that it can alleviate the chattering phenomenon and ensure the convergence speed. Second, target maneuvers are considered as system disturbances, and the head-pursuit guidance law based on an observer is proposed. Furthermore, this method is extended to a three-dimensional case. Finally, comparative simulation results further verify the superiority of the guidance laws designed in this article.


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