scholarly journals Lateral Stability Performance of Articulated Narrow-Track Tractors

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2512
Author(s):  
Bruno Franceschetti ◽  
Valda Rondelli ◽  
Enrico Capacci
Keyword(s):  
Kinematic Model ◽  
Joint Modeling ◽  
Design Stage ◽  
Lateral Stability ◽  
Track Width ◽  
Pivot Point ◽  
Stability Performance ◽  
Contact Points ◽  
The Stability ◽  
Yaw Angle

A tractor losing lateral stability starts to rollover. It is a matter of fact that tractor lateral rollover accidents are one of the most frequent causes of death and injuries for farmers. Consequently, tractors are fitted with a specific protective structure to minimize the consequences for the driver during the rollover (ROPS). The narrow-track tractor, designed to operate in vineyards and orchards, is a tractor category with a very narrow track width and the risk of rollover is higher. The aim of the study was to evaluate the compact narrow-track tractor types commercially available, designed to mount a cantilever engine in the forward position with effects on the Center of Gravity (CoG) because more than 50% of the tractor weight is loaded on the front axle, and, specifically, the articulated narrow-track tractors where the stability is affected by the pivot point connecting the two tractor bodies. As a consequence of the typical tractor design of articulated tractors, during the steering action the line passing through the front and rear tire contact points on the ground changes, influencing the tractor’s stability. The approach of the research was based on reproducing the lateral stability tractor condition by developing a kinematic model, with the goal to virtually simulate the tractor behavior and to calculate the lateral stability angle for articulated tractors. The innovative contribution of this paper was the tractor articulation joint modeling, assuming a virtual pivot point to reproduce two relatives’ rotations between the front and rear bodies of the tractor: vertical (yaw angle) and longitudinal (roll angle) rotations. The lowest value of the stability angle was 39.3°, measured at −35° yaw angle. The model at the tractor design stage will allow adjusting of the tractor parameters to improve the lateral stability performance.

A new hybrid force-position measure approach on the stability for a camera robot

2015 ◽  
Vol 230 (14) ◽  
pp. 2508-2516 ◽  
Author(s):  
Peng Liu ◽  
Yuanying Qiu ◽  
Yu Su
Keyword(s):  
Performance Index ◽  
Horizontal Plane ◽  
Kinematic Model ◽  
Robot Simulation ◽  
Stability Performance ◽  
Simulation Results ◽  
The Stability ◽  
Position Measure

In order to evaluate the stability of a camera robot, a new stability performance index with combination of force and position based on the determinations of the cable tensions is proposed in this paper. First, two position factors based on the kinematic model of the camera robot are presented to show how far the specified position is away from the center of the horizontal plane at which the specified position locates within the workspace and how far the specified position is away from the top of the workspace, respectively. Then, two force factors are also developed to show the distributions of the minimum cable tensions in the specified region of the workspace. Furthermore, the stability performance index is described using the weighted method. And subsequently, the stability workspace is designed with the stability performance index. Finally, a robustness workspace with the external wrench is selected to demonstrate the effectiveness of the stability performance index above for the camera robot. Simulation results show that it is suitable to employ stability performance index to evaluate the stability of the camera robot.

A Study of the Lateral Stability of Railroad Vehicles Using a Nonlinear Constrained Multibody Formulation

2001 ◽  
Author(s):  
Davide Valtorta ◽  
Khaled E. Zaazaa ◽  
Ahmed A. Shabana ◽  
Jalil R. Sany
Keyword(s):  
Stability Analysis ◽  
Linear Stability ◽  
Linear Theory ◽  
Linear Stability Analysis ◽  
Numerical Study ◽  
Operating Conditions ◽  
Lateral Stability ◽  
Railroad Vehicles ◽  
Contact Formulation ◽  
The Stability

Abstract The lateral stability of railroad vehicles travelling on tangent tracks is one of the important problems that has been the subject of extensive research since the nineteenth century. Early detailed studies of this problem in the twentieth century are the work of Carter and Rocard on the stability of locomotives. The linear theory for the lateral stability analysis has been extensively used in the past and can give good results under certain operating conditions. In this paper, the results obtained using a linear stability analysis are compared with the results obtained using a general nonlinear multibody methodology. In the linear stability analysis, the sources of the instability are investigated using Liapunov’s linear theory and the eigenvalue analysis for a simple wheelset model on a tangent track. The effects of the stiffness of the primary and secondary suspensions on the stability results are investigated. The results obtained for the simple model using the linear approach are compared with the results obtained using a new nonlinear multibody based constrained wheel/rail contact formulation. This comparative numerical study can be used to validate the use of the constrained wheel/rail contact formulation in the study of lateral stability. Similar studies can be used in the future to define the limitations of the linear theory under general operating conditions.

Experimental Study on the Stability Performance and Turning Motion of Multi-Connection VAWT

2021 ◽  
Author(s):  
Saika Iwamatsu ◽  
Yasunori Nihei ◽  
Kazuhiro Iijima ◽  
Tomoki Ikoma ◽  
Tomoki Komori
Keyword(s):  
Scaling Law ◽  
Type A ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Water Tank ◽  
Type B ◽  
Floating Bodies ◽  
Stability Performance ◽  
Turning Motion ◽  
The Stability

Abstract In this study, a series of dedicated water tank tests were conducted in wind and waves to investigate the stability performance and turning motion of Floating Offshore Wind Turbine (FOWT) equipped with two vertical axis wind turbines (VAWT). The FOWT targeted in this study is called Multi-connection VAWT, which is a new type of FOWT moored by Single-Point-Mooring (SPM) system. We designed and manufactured two types of semi-submersible floating bodies. One is a type in which VAWTs are mounted in two places of a right-angled isosceles triangle (Type-A) on a single floater, and the other is two independent units equipped with VAWTs on two separate floaters centered on a moored body. This is a type in which two semi-submersible floating bodies are lined up in a straight line (Type-B). The experimental conditions were determined by scaling down to 1/100 using Froude’s scaling law based on a wind thrust load of 320 kN (rated wind speed of 12 m/s) assuming an actual machine. In the free yawing test in waves, Type-A turned downwards, while Type-B was barely affected by the waves. Furthermore, in the free yawing test in wind, both Type-A and Type-B turned leeward and stabilized at a final point where the wind load was balanced.

Vehicle Lateral Motion Control Based on Estimated Stability Regions

2017 ◽  
Author(s):  
Yiwen Huang ◽  
Yan Chen
Keyword(s):  
Measurement Errors ◽  
Local Stability ◽  
Stability Region ◽  
Control Method ◽  
Linearization Method ◽  
Stability Control ◽  
Lateral Stability ◽  
Shortest Distance ◽  
The Stability ◽  
Yaw Moment

This paper presents a novel vehicle lateral stability control method based on an estimated lateral stability region on the phase plane of vehicle yaw rate and lateral speed, which is obtained through a local linearization method. Since the estimated stability region does not only describe vehicle local stability, but also define the oversteering and understeering characteristics, the proposed control method can achieve both local stability and vehicle handling stability. Considering the irregular geometric shape of the estimated stability region, a stability analysis algorithm is designed to determine the distance between vehicle states and stability region boundaries. State estimation or measurement errors are also incorporated in the distance calculation. Based on the calculated shortest distance between vehicle states and stability boundaries, a direct yaw moment controller is designed to maintain vehicle states stay within the stability region. CarSim® and Simulink® co-simulation is applied to verify the control design through a cornering maneuver. The simulation results show that the proposed control method can make the vehicle stay within the stability region successfully and thus always operate in a safe manner.

scholarly journals Optimal Location and Design of TCSC controller For Improvement of Stability

2011 ◽  
pp. 210-215
Author(s):  
Swathi Kommamuri ◽  
P. Sureshbabu
Keyword(s):  
Power System ◽  
Optimization Problem ◽  
Low Frequency ◽  
System Stability ◽  
Simulation Environment ◽  
Swarm Optimization ◽  
Stability Performance ◽  
Low Frequency Oscillations ◽  
Simulation Results ◽  
The Stability

Power system stability improvement by a coordinate Design ofThyristor Controlled Series Compensator (TCSC) controller is addressed in this paper.Particle Swarm Optimization (PSO) technique is employed for optimization of the parameterconstrained nonlinear optimization problem implemented in a simulation environment. The proposed controllers are tested on a weakly connected power system. The non-linear simulation results are presented. The eigenvalue analysis and simulation results show the effectiveness and robustness of proposed controllers to improve the stability performance of power system by efficient damping of low frequency oscillations under various disturbances.

scholarly journals PENGARUH GENOTIPE, LINGKUNGAN, DAN INTERAKSI KEDUANYA TERHADAP STABILITAS PENAMPILAN FENOTIPIK IKAN MAS

2019 ◽  
Vol 13 (4) ◽  
pp. 289
Author(s):  
Didik Ariyanto ◽  
Suharyanto Suharyanto ◽  
Flandrianto Sih Palimirmo ◽  
Yogi Himawan
Keyword(s):  
Common Carp ◽  
Cyprinus Carpio ◽  
Environmental Conditions ◽  
Culture Systems ◽  
Stability Performance ◽  
Carp Cyprinus Carpio ◽  
Culture Environment ◽  
Net Cage ◽  
The Stability ◽  
Concrete Pond

Ikan mas (Cyprinus carpio) merupakan komoditas budidaya yang mudah beradaptasi dengan berbagai kondisi lingkungan. Penelitian ini bertujuan mempelajari pengaruh genotipe, lingkungan, dan interaksi antara genotipe dengan lingkungan terhadap stabilitas penampilan fenotipik ikan mas dalam kegiatan budidaya. Rancangan percobaan menggunakan rancangan faktorial 3 x 5 dengan lima ulangan. Lima strain ikan mas, yaitu Rajadanu, Sutisna, Majalaya, Wildan, dan Sinyonya dipelihara secara komunal di dalam tiga model wadah budidaya, yaitu kolam beton, kolam jaring, dan kolam tanah, selama 90 hari. Hasil penelitian menunjukkan bahwa penampilan fenotipik ikan mas dipengaruhi oleh genotipe, lingkungan dan interaksi kedua faktor tersebut. Strain Sutisna dan Wildan mempunyai nilai sintasan yang paling baik di semua lingkungan dibanding tiga strain lainnya. Strain Sutisna mempunyai pertumbuhan terbaik di kolam tanah sedangkan strain Wildan di kolam jaring. Hal ini menyebabkan kedua strain tersebut menghasilkan biomassa panen terbaik pada lingkungan yang berbeda. Hasil analisis stabilitas menunjukkan bahwa kelima strain ikan mas dalam penelitian ini relatif tidak stabil dan mempunyai respons yang berbeda jika dipelihara pada lingkungan yang berbeda. Strain Wildan dan Rajadanu merupakan strain ikan mas yang mempunyai respons terhadap perbedaan lingkungan paling tinggi. Strain dengan karakteristik tersebut akan mempunyai performa terbaik pada lokasi dan kondisi pemeliharan yang sesuai dengan kebutuhannya, tetapi mempunyai penampilan fenotipik yang rendah jika kondisi lingkungan budidayanya tidak sesuai. Strain Sutisna, Sinyonya, dan Majalaya merupakan strain ikan mas dengan daya responsi terhadap lingkungan lebih rendah. Karakteristik ini menyebabkan penampilan fenotipik ketiga strain tersebut relatif stabil pada semua lokasi dan kondisi budidaya, meskipun tidak bisa mencapai hasil yang maksimal.Common carp (Cyprinus carpio) is known as fish species highly adaptable to various environmental conditions. This study aimed to evaluate the effect of genotype, environment, and their interaction in phenotypic performance stability of common carp. The experimental design used a 3 x 5 factorial design with five repetitions. Five strains of common carp, namely Rajadanu, Sutisna, Majalaya, Wildan, and Sinyonya were stocked communally for 90 days in three culture systems: concrete pond, net cage pond, and earthen pond. The result showed that the phenotypic performance of common carp was influenced by genotype, environment, and their interaction. Sutisna and Wildan strains have a higher survival rate compared to other strains in all culture systems. Sutisna and Wildan strains have the best growth performance in the earthen pond and net cage pond, respectively. Both strains also have the highest biomass production at harvest in all culture systems. Based on the stability performance analysis, Wildan and Rajadanu have the highest response to the different environmental conditions. Strains with this characteristic perform best in different locations or culture systems as long as the environmental conditions are suitable. However, these fish will likely perform poor in the unsuitable culture environment. Sutisna, Sinyonya, and Majalaya are carp strains with lower responsiveness to environmental change. Such characteristic causes the phenotypic performance of these three strains cannot achieve the maximum results, yet it is relatively stable in all locations.

scholarly journals Backstepping sliding mode controller improved with fuzzy logic: Application to the quadrotor helicopter

2012 ◽  
Vol 22 (3) ◽  
pp. 315-342 ◽  
Author(s):  
Samir Zeghlache ◽  
Djamel Saigaa ◽  
Kamel Kara ◽  
Abdelghani Harrag ◽  
Abderrahmen Bouguerra
Keyword(s):  
Fuzzy Logic ◽  
Control Method ◽  
Sliding Mode ◽  
Design Method ◽  
Stability And Convergence ◽  
Sliding Mode Controller ◽  
Quadrotor Helicopter ◽  
Nonlinear Control Method ◽  
The Stability ◽  
Yaw Angle

Abstract In this paper we present a new design method for the fight control of an autonomous quadrotor helicopter based on fuzzy sliding mode control using backstepping approach. Due to the underactuated property of the quadrotor helicopter, the controller can move three positions (x;y; z) of the helicopter and the yaw angle to their desired values and stabilize the pitch and roll angles. A first-order nonlinear sliding surface is obtained using the backstepping technique, on which the developed sliding mode controller is based. Mathematical development for the stability and convergence of the system is presented. The main purpose is to eliminate the chattering phenomenon. Thus we have used a fuzzy logic control to generate the hitting control signal. The performances of the nonlinear control method are evaluated by simulation and the results demonstrate the effectiveness of the proposed control strategy for the quadrotor helicopter in vertical flights.

Sign in / Sign up

Export Citation Format

Share Document