• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.819-826
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• 2000

This study was performed to develop a measurement system of tractor field performance for plow and rotary operations. Measurement system for tractor consisted of torque sensors to measure torque of drive axles and PTO axle, speed sensors to measure rotational speed of drive axles and engine, microcomputer to control data logger, and data logger as I/O interface system. The measurement system was installed on four-wheel-drive tractor. Four-element full-bridge type strain gages were used for torque measurement of drive axles and optical encoders were used to measure speeds of drive axles and engine. Slip rings were mounted on the rotational axles. Signals from sensors were inputted to data logger that was controlled by microcomputer with parallel communication. Sensors were calibrated before the field tests. Regression equations were found on completion of the calibrations. The field experiment was performed at paddy fields and uplands. Rotary and plow were used when the tractor was operated in the field. Travelling speeds of the tractor were 1.9 km/h, 2.7 km/h, 3.7 km/h, 5.5 km/h, 8.2 km/h, and 11.8 km/h. Operating depths of implements were maintained approximately 20cm during the tests. Torque data of drive axles were different at each location during plow and rotary operations. Results showed that torque of rear axles were greater than those of front axles. Total torque were 6860 - 11064 Nm at the upland and 7360 - 14190 Nm at the paddy field for plow operations. It was found that torque at the paddy field were about 20% greater than those at the upland for plow operations. Torque data showed that rotary operations required less power than plow operation at the paddy field and the upland. Torque measurements at each axle for rotary operations were only 8 - 16% of plow operations in the upland and 15 - 20% in the paddy field.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.4
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• pp.8-15
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• 2013

Recently many kinds of electric vehicles have been developed as many governments demand the environmental friendly vehicles. In this paper, study of load optimization for the electric vehicle which has multiple axle power system was conducted. For the analysis of the vehicle which has three or four driving axles, a method based on the geometry and assumptions that considering axles as a spring model and normal forces of the axles are proportional to the displacement of the axles was applied with basic vehicle dynamics. With the developed vehicle analysis technique, algorithm to find the optimal motor operating points was developed. Using this algorithm, it was possible to find the optimization of vehicle load distribution for multiple axles according to the driving cycles. Also, control logic for the vehicle can be developed based on the optimization simulation results.

• Journal of the Korean Society of Industry Convergence
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• v.11 no.2
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• pp.59-64
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• 2008

Elements of a mechanical structure are getting from multi-axles stress. so fatigue characteristic experiment Shall execute in multi-axles stress state. it is very hard to apply according to forms of a testing machine and implementation. In this study, 2 axles fatigue testing machine did a design and Development. a new JIG developed to realize a mixed mode. a stress state in mixed mode of a specimen had each other comparison using the Finite element method to examine propriety of a new JIG.

• International Journal of Railway
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• v.2 no.1
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• pp.8-17
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• 2009

The wheelset, its functions and position under the train is the prime safety-critical component. Whether in design, qualification, manufacturing or maintenance, the wheels and axles have been the focus of special attention at SNCF for over 25 years and the French Railways are actively involved in various Research and Development work towards interoperability between the railways, railway reliability and running safety.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.5
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• pp.579-590
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• 2012

Weight reduction of a railway axle, which is one of heaviest parts in an urban railway vehicle, is discussed in this paper. A wheelset of a railway vehicle is very important with regard to railway safety, and its structural strength should always be considered when attempting to reduce the railway axle weight. In this work, the weight of the axles of a trailer bogie and a motor bogie of the Korean EMU was reduced by replacing solid axles with hollow axles. On the basis of the EN standard for railway axle design, the strength of existing solid axles was analyzed and the required bore size of a hollow axle was determined. It is shown that the weight of the concurrent axle of the Korean EMU can be reduced by up to 20% with a very small decrease in the structural strength. Finite element analyses were also carried out to verify the design result for lightweight hollow axles.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.5
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• pp.83-89
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• 2010

In this paper, the dynamic response of a CNC 5 Axles machining center was analyzed and then controlled passively by using the dynamic absorber. For the simplification of the theoretical approach, the CNC 5 Axles machining center was modeled as a flexible beam(Bed) having a point mass(Column), two discrete systems(a Table-set and a dynamic absorber). Specifically by using the dynamic absorber, the dynamic response of a Table-set which be caused by the vibration of a flexible beam, was reduced down to the infinitesimal level. The optimal design factors of the dynamic absorber were obtained from the minimization of the cost function. It was found that the natural frequencies of a UT-380 machining center be varied due to the movement of the Table-set. In view of the dynamic response of a Table-set, the larger spring stiffness and mass of the dynamic absorber were found to give the greater reduction.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.147-150
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• 2005

The torsion beam axle type is widely used in the rear suspension for small passenger car because of low cost, good performance and etc. The FE and dynamic analysis using the computer are very helpful for the efficiency of the torsion beam design. First of all, the reliability on the computational model must be verified for the analysis. In this study, The FE model of the torsion beam was verified according to comparison with he test data. And after making the flexible body using the FE model, the dynamic characteristic of the tubular type torsion beam axles was compared with that of the V-beam type.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.1
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• pp.144-151
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• 2008

The bi-modal vehicle is composed of two car-bodies and three axles. Each axle of the vehicle has an independent suspension and all wheels are steerable. Since the bi-modal vehicle has longer wheelbase than most urban buses, the All-Wheel-Steering(AWS) system is adapted for to ensure safe driving and proper turning radius on a curved road. This paper proposes an AWS control algorithm for stable driving of bi-modal vehicle. Steering angles and directions of each axle of bi-modal vehicle changed according to the driving environment and steering modes. In the case that front and rear axles should be steered in opposite directions is a negative mode, and the other case that the axles should be steered in the same direction is a positive mode. For example, in the positive mode, front and real axles are steered in the same direction, while in the negative mode, they are steered in the opposite direction. A multibody model of the vehicle is used to verify the performance of the steering algorithm and simulation results of 2WS are compared with those of AWS under the same condition.

• Journal of Korean Society of Steel Construction
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• v.23 no.3
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• pp.397-404
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• 2011

In this paper, a research for the dynamic wheel loads of a 3D vehicle model, which relates to a tire-enveloping model, is carried out. A single truck with four axles is modeled as a 10-D.O.F. vehicle by modeling both contact length of tires and pitching of tandem spring axles. The dynamic equations of the vehicle are obtained using the Lagrange's equation, the solution of the equations is calculated by Newmark-${\beta}$ method. The validity of the developed 3D vehicle model is demonstrated by comparing results obtained from the proposed method with those from experimental data. The maximum impact factors of tire force are evaluated according to the various step bumps on which a 24-ton dump truck is running.

• Journal of Drive and Control
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• v.17 no.4
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• pp.152-159
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• 2020

This study reviews the rear or tag axle steering system's concepts and technology applied to commercial vehicles. Most commercial vehicles are large in size with more than two axles. Maneuvering them around tight corners, narrow roads, and spaces is a difficult job if only the front axle is steerable. Furthermore, wear and tear in tires will increase as turn angle and number of axles are increased. This problem can be solved using rear axle steering technology that is being used in commercial vehicles nowadays. Rear axle steering system technology uses a cylinder mounted on one of rear axles called a steering cylinder. Cylinder control is the primary objective of the real axle steering system. There are two types of such steering mechanisms. One uses master and slave cylinder concept while the other concept is relatively new. It goes by the name of smart axle, self-steered axle, or smart steering axle driven independently from the front wheel steering. All these different types of steering mechanisms are discussed in this study with detailed description, advantages, disadvantages, and safety considerations.