The 10th International Conference on Ubiquitous Robots and Ambient Intelligence (URAI 2013) Oct. 30 -- Nov. 2, 2013 at Ramada Plaza, Jeju, Korea Design of a 5 th -polynomial high speed cam-based intermittent four-bar linkage mechanism Jing Wu 1 , Rui-Jun Yan 1 , Kyoosik Shin 2 1 Department of Mechatronics Engineering, Hanyang University, Ansan, 426-791, Korea (E-mail: wujing@hanyang.ac.kr ; yrj@hanyang.ac.kr ) 2 Department of Robot Engineering, Hanyang University, Ansan, 426-791, Korea (E-mail: norwalk87@hanyang.ac.kr* ) *Corresponding author Abstract - With the higher demands of speed and accuracy for automatic mechanism, the diversified parameters and kinematics issues have been paid much more attention in the field of cam research. This paper introduced a special cam-based intermittent linkage mechanism that would produce an ideal application in high speed motion. On the basis of analyzed and compared the basic standing kinematics cam curves, from the point of view of kinematic characteristic, analysis the curve characteristic (the units of kinematics eigenvalue, such as displacement, speed, acceleration and so on), the 5 th polynomial profile curve is established. In this paper, kinematic analysis of this cam-based linkage mechanism was done by separate the system into two parts for its one kind of closed-chain structure. Keywords - Polynomial-curve, High-speed cam, closed-chain linkage system, kinematics. 1. Introduction Cam-follower mechanisms are found in almost all mechanical devices and machines, not only because of arbitrarily complicated motions have been achieved by the brief simple-compact cam-based construction, but also based on the good motion rigidity and the ability to achieve complex expected movement, especially for those systems witch has constant displacement, velocity and acceleration. It is possible to construct a cam blending crude increments and observing its appearance. But this method is not acceptable in the design of today’s cam machinery. Nowadays cam designs are mostly depend on accurate mathematical information for the cam characteristics of displacement velocity, acceleration, and sometimes the jerk. In so doing one can interpret and control the ultimate design performance. The higher the cam speed, the more critical is the investigation. This is especially true of the acceleration data, which is the important determining factor of the dynamic loads on cam-follower in high-speed systems. Cam curve can be design not only by this curves witch are based on the numerical method but also calculate profile curve use the convolution filtering method and the acceleration-combination method in cam follower curve design [1]. Cam can be designed for any acceptable curve or shape. Basic curves are the first selection to establish the follower action for they are easy to analyze and manipulate. However, for most of the high-speed cams, just depends on basic curves are not enough. In this paper, we introduced the 5 th polynomial curve which is an ideal curve for the high-speed mechanism. Based on this special designed cam, the four-bar linkage mechanism should have a high-speed and intermittent trajectory that can be used as an arm or a manipulator by combined with some more structures. Since the analysis of a four bar linkage can’t be easily build as a linkage system, so the system would be separated into more then one loop [2]. This paper shows the kinematic equations of the system witch is separate into two loops based on the two driver torque. 2. Design 2.1 Definite the high-speed cam Since the motion torque of the linkage intermittent mechanism is based on the high-speed cam, it is necessary to give an definition of a high-speed cam. Investigation provides two different standards, U.S. standard of high speed cam is given as: 1 1 / 10 : Cam design revolving speed : Mechanism inherent frequency. When 1, high speed cam. d n n d ω ω ω ω - = ≤ (1) Even though the cam design revolving speed and the mechanism inherent frequency could be found from some cam elements, but for most of the cam, the inherent frequency is difficult to calculate. Japanese Standard of high speed cam is basced on the Automatic machine standard as: max max max max max max Low speed mechanism 1 or 1 / Medium speed mechanism 1 3 or 1 / 2 / High speed mechanism 3 8 or 2 / 3 /. Here, is the gravity acceleration. a g v m s g a g m s v m s g a g m s v m s g ≤ ≤ ≤ ≤ ≤ ≤ ≤ ≤ ≤ ≤ (2) In this paper, we defined the high-speed cam in view of the Japanese standard by the cam maximum acceleration of follower as: 2013 10th International Conference on Ubiquitous Robots and Ambient Intelligence (URAI) October 31-November 2, 2013 / Ramada Plaza Jeju Hotel, Jeju, Korea 978-1-4799-1197-4/13/$31.00 ©2013 IEEE 584