• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.11
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• pp.1319-1326
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• 2012

This study focuses on the influence of tractive forces on the self-stability of a bicycle. The eigen-value analysis of the self-stability of a passive rider control linear bicycle model can be used to analyze the self-stability. A linear bicycle model with front and rear driving forces is developed. The influence of tractive forces on the self-stability is identified by using the developed model. A nonlinear multi-body bicycle model is used to confirm the results of the linear analysis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.604-609
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• 2002

In development of an advanced bicycle simulator, the investigation of the interactions between bicycle and rider during cycling is paramount important because bicycle is a two-wheeled human-powered vehicle. Tn this work, the tilt stability. among various interactions, of bicycling is investigated experimentally, In the experiments, the tilt angles of the bicycle, riders body and head are measured, as the riding p;1th and the speed are varied. Subjects are asked to ride along four typical paths on rigid flat ground : the straight, C-curved, S-curved and circle paths. The results from extensive experiments with different subjects can be summarized as : 1) The tilt angles of bicycle and rider are almost out of phase during pedaling along the straight path. 2) The bicycle tilt angle is nearly proportional to the square of bicycle speed for the straight and curved paths, and to the curvature for the curved paths. The head tilt angle is the biggest and the body tilt angle is the smallest for the straight path, but the tendency is reversed for the C-curved path. During the curve maneuvering, the rider's head tends to tilt by less than 40% of the bicycle tilt angle.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.6
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• pp.93-100
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• 2013

This paper presents the development process for a bicycle monocoque frame using bolt fastening. Traditionally, bicycle frames have been constructed with metal tubes joined at their ends by welding. These frames have been brazed or soldered onto metal lugs, forming the frame. Because stress loads become greatest at the joint of the bicycle tube frame, joint construction strongly influences frame design and construction. To avoid the inherent problems of material discontinuity at frame joints, numerous designers have attempted to reduce or eliminate the number of joints in tube frames. Nevertheless, the manufacture of high quality, reliable, one-piece and jointless frames has proven difficult and expensive. In this study, a new monocoque frame adapted to a hybrid bike is proposed. The advantage of the monocoque frame, is theat is has a rechargeable battery system that is built into the frame; as a result, the emotional quality for the customer is improved. In order to estimate the design compatibility compared with that of tube frames, structural analysis is performed using finite element method. A prototype based on a modified design has also been made and stability testing has been carried out.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.6
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• pp.267-278
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• 2000

Vehicle dynamic models in handing and stability analysis are divided into three groups: bicycle model, roll axis model and full vehicle model. Bicycle model is a simple linear model, which hag two wheels with load transfer being ignored. Roll axis model treats left and right wheels independently. In this model, load transfer has a great effect on nonlinearity of tire model. Effects of suspension system can be analyzed by using full vehicle model, which is included suspension stroke motions. In this paper, these models are validated and compared through comparison with road test, and the effects of suspension kinematics and compliance characteristics on vehicle motion are analyzed. In handling and stability analysis, roll axis model can simulate the real vehicle motion more accurately than full vehicle model. Compliance steer has a significant effect, but the effect of suspension kinematics is negligible.

• Journal of Korean Society of Transportation
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• v.30 no.3
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• pp.43-55
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• 2012

Bicycle is an environment-friendly transport mode contributing to a more sustainable transportation systems. To innovatively increase the use of bicycle as a significant transport mode, bicycle-friendly roadway environment should be provided. This study proposes a method to evaluate cycling environment based on the analysis of data collected from an specially equipped probe bicycle. The inertial measurement unit(IMU) consisting of a gyro sensor, accelerometer, and a global positioning systems(GPS) receiver was installed on the probe bicycle. Cycling stability index(CSI) and bicycle speed data were used as inputs of the proposed evaluation framework adopting the Fault Tree Analysis, which is a well-known technique for the risk analysis. The outcomes of this study will serve as an intelligent assesment tool for cycling environment.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.04a
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• pp.446-449
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• 2004

In the former researches〔2〕〔5〕 for the unmanned bicycle system, we do only focus on stabilizing it by using the lateral motion of mass which plays important role in driving a bicycle system. In this papers, we suggest an algorithm for deriving steering angle and speed for a given desired tracking path. As you may see in this paper, load mass balance system plays important role in stabilization and it is also discussed. We propose a control algorithm for the autonomous self stabilization of unmanned bicycle by using nonlinear compensation-like control based on the Lyapunov stability theory We then propose a tracking control strategy by moving the center of load mass left and right respectively. From the computer simulation results, we can show the effectiveness of the proposed control strategy.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.2
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• pp.147-156
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• 2016

In this paper, optimal designs of bicycle frame were studied for weight reduction of bicycle using carbon-fiber-reinforced plastic (CFRP), glass-fiber-reinforced plastic (GFRP) and Kevlar-fiber-reinforced plastic (KFRP), respectively. Based on the anisotropic properties of FRP material, stacking angle and thickness optimization were performed under the safety reference of European committee for standardization (CEN) to ensure the stability of bicycle frame. Finally, performances of FRP bicycle frame was evaluated by digital logic method based on the optimized results of weight, strength properties and cost. Then, the optimized bicycle frame composed of each FRPs were evaluated and ranked by total performance values.

• Proceedings of the KIEE Conference
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• 2001.07e
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• pp.95-99
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• 2001

In this paper, a drive system for multi-phase bipolar brushless DC (MPB BLDC) motor is presented. This drive system is used for an electric bicycle. In general, the maximum and minimum speed of electric bicycle are required by law. At first, the proposed controller is satisfied for the limited speed control. Secondly, the system has a technique of exited with modulation(EWM), bidirection control, and partial square wave control. Thirdly, the controller is designed for system stability Experimental results show the performance of the proposed controller of MPB BLDC motors for an electric bicycle.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.50 no.3
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• pp.117-124
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• 2001

The aim of this paper is to develop a controller of multi-phase bipolar brushless DC (MPB BLDC) motors for an electric bicycle. A MPB BLDC motor has a Permanent magnet rotor in which the magnetic arrangement is radial to the shaft and integral to the rotor laminations. This technique concentrates flux, giving a higher flux density than a surface-mounted PM motor and increases reluctance torque. The stator of MPB BLBC motor has parallel winding, allowing multi-phase separate independent controllability. It gets much more high power than wye-connection at same low voltage. The conventional techniques of exited with modulation(EWM), bidirection control, and partial square wale control are Proposed with one H-bridge and two photo sensors per phase. The Proposed controller is satisfied for the limited speed control and designed for system stability Experimental results show the performance of the proposed controller of MPB BLDC motors for an electric bicycle.

• Journal of Mechanical Science and Technology
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• v.19 no.spc1
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• pp.292-304
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• 2005

In this paper we present the linearized equations of motion for a bicycle as a benchmark. The results obtained by pencil-and-paper and two programs are compared. The bicycle model we consider here consists of four rigid bodies, viz. a rear frame, a front frame being the front fork and handlebar assembly, a rear wheel and a front wheel, which are connected by revolute joints. The contact between the knife-edge wheels and the flat level surface is modelled by holonomic constraints in the normal direction and by non-holonomic constraints in the longitudinal and lateral direction. The rider is rigidly attached to the rear frame with hands free from the handlebar. This system has three degrees of freedom, the roll, the steer, and the forward speed. For the benchmark we consider the linearized equations for small perturbations of the upright steady forward motion. The entries of the matrices of these equations form the basis for comparison. Three diffrent kinds of methods to obtain the results are compared : pencil-and-paper, the numeric multibody dynamics program SPACAR, and the symbolic software system Auto Sim. Because the results of the three methods are the same within the machine round-off error, we assume that the results are correct and can be used as a bicycle dynamics benchmark.