• Tribology and Lubricants
• /
• v.16 no.4
• /
• pp.289-294
• /
• 2000

This paper present the contact stresses, which considers the shear stress at the cam and follower interface in the direct acting type valve train system of a high speed engine. To determine the contact condition, the normal contact forces are calculated by using the lumped mass dynamic modeling. The line contact is considered between the cam and follower interface. The variations of dynamic stresses are presented as a function of camshaft rotational angle. Also the effects of various design parameters are investigated.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.22 no.3
• /
• pp.519-528
• /
• 1998

A numerical method is presented for the dynamic analysis of cam and follower. Contact and separation between the cam and the follower are analyzed by imposing dynamic contact condition. The correct solution is obtained without spurious oscillation by imposing the velocity and acceleration constraints as well as the displacement constraint on the possible contact point. The constraints are satisfied by iteratively reducing the constraint errors toward zero, and a simple time integration of ordinary differential equation is employed for the solution of the equation of motion. The solution procedure associated with the iterative scheme is presented, and numerical simulations are conducted to demonstrate the accuracy of the solution.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.11 no.1
• /
• pp.124-131
• /
• 1987

The parameteric instability of the cantilever beam carrying two concentrated masses subjected to a periodic follower force is investigated theoretically and experimentally. The effects of the constant follower force and the periodic follower force the mass ratio and the location of the concentrated mass on the parametric instability of the system are discussed. In experiment, the nonconservative follower force is produced by the magnetic force of the electromagnet. The theoretical and the experimental results on the parameteric instability are in good agreement each other.

• Journal of the Korean Society for Precision Engineering
• /
• v.21 no.1
• /
• pp.167-172
• /
• 2004

A method for the design of a disk cam with a remote follower is presented. ADAMS software is utilized for the design process. The whole process is applied for the design of a cam profile to be used in a tappet shedding device of a shuttle loom. First the desired motion of the remote follower, the hearld frame in this case, is determined to improve the characteristic of a certain weaving process. Next, the desired displacement data is input to the ADAMS software and the cam profile is obtained as an output. To test the validity of the proposed method, designed cams were actually manufactured and implemented on a experimental loom. And with the help of potentiometer type displacement transducers, the motion of the remote followers were actually recorded. And the result was sufficient to prove the validity of the presented method.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.1 s.94
• /
• pp.125-131
• /
• 1999

For linkage mechanisms driven by a cam, cam profile is the major design factor and is determined by the cam follower motion. If a cam mechanism has additional kinematic linkage besides cam and follower then the follower motion should be specified from the motion of end linkage member so that cam would be able to generate the desired end linkage motion. In this paper, a cam-linkage mechanism is constructed with the combinations of modular linkage elements including cam and follower and as a result, a planar cam-linkage mechanism design software with the cam profile optimization function is developed and presented.

• Journal of KSNVE
• /
• v.7 no.3
• /
• pp.439-447
• /
• 1997

In this study, the dynamic instabilities of a nonlinear elastic system subjected to follower forces are investigated. The two-degree-of-freedom double pendulum model with nonlinear geometry, cubic spring, and linear viscous damping is used for the study. The constant, the initial impact forces acting at the end of the model are considered. The chaotic nature of the system is identified using the standard methods, such as time histories, power density spectrum, and Poincare maps. The responses are chaotic and unpredictable due to the sensitivity to initial conditions. The sensitivities to parameters, such as geometric initial imperfections, magnitude of follower force, direction control constant, and viscous damping, etc., are analysed. Dynamic buckling loads are computed for various parameters, where the loads are changed drastically for the small change of parameters.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2000.11a
• /
• pp.612-615
• /
• 2000

Cam mechanism is one of the common devices used in many automatic machinery. Specially cylindrical cam generates three dimensional motions. Thus, the shape design procedures must have high accuracy. This paper proposes the shape design procedure for a cylindrical cam and follower mechanism using a relative velocity method. The relative velocity method and the coordinate transformation are used to find a contact point between the cam and the follower. Also, the full shape of the cylindrical cam can be generated by using the geometric relationships and the contact constraints. As a result, this paper presents an example for the shape design of the cylindrical cam in order to prove the accuracy of the design procedures.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.06a
• /
• pp.701-705
• /
• 2000

On the dynamic behavior of a simple beam subjected to an uniformly distributed tangential follower force, the influences of the velocities and magnitudes of a moving mass have been studied by numerical method. The instant amplitude of a simple beam is calculated and analyzed for each position of the moving mass represented by the time functions. The uniformly distributed tangential follower force is considered in its critical value of a simple beam, and four values of velocity is also chosen. Their coupling effects on the deflections of a simple beam are inspected too. When a moving mass moves after middle zone of a simple beam at the low velocities, its deflection is increased by the coupling of an uniformly distributed tangential follower force and moving mass.

• Journal of Institute of Control, Robotics and Systems
• /
• v.15 no.1
• /
• pp.8-14
• /
• 2009

A formation flight guidance logic that enables the leader-follower station keeping between two UAVs is presented in this paper. The logic is motivated by the investigation of the relation between the proportional navigation and the nonlinear trajectory tracking guidance law, The simplicity of the presented method provides computational efficiency and allows easy implementation. An excellent performance of the proposed logic is demonstrated via various numerical simulations for multiple UAVs environment.

• Journal of applied mathematics & informatics
• /
• v.28 no.3_4
• /
• pp.597-610
• /
• 2010

For a class of nonlinear bilevel programming problems in which the follower's problem is linear, the paper develops a genetic algorithm based on the optimality conditions of linear programming. At first, we denote an individual by selecting a base of the follower's linear programming, and use the optimality conditions given in the simplex method to denote the follower's solution functions. Then, the follower's problem and variables are replaced by these optimality conditions and the solution functions, which makes the original bilevel programming become a single-level one only including the leader's variables. At last, the single-level problem is solved by using some classical optimization techniques, and its objective value is regarded as the fitness of the individual. The numerical results illustrate that the proposed algorithm is efficient and stable.