Determination of servomotor parameters of a tripod-based parallel kinematic machine

This paper presents a comprehensive methodology to determine the servomotor parameters of a parallel kinematic machine according to the design specifi cations in terms of the cutting load, fast feed rate and accelerating capab ilities. Due to the characteristics of the parallel format, the singular va lue decomposition technique is employed to determine the lower and upper bo unds of the servomotor parameters such as the rated speed and torque. An ap proach is also developed to determine the maximum equivalent moment of iner tia of the platform and struts reduced onto a servo axis, which therefore a llows the accelerating capability of the servo system to be examined in ter ms of the maximum torque required. The effectiveness of this methodology is exemplified by the application to a tripod-based parallel kinematic machin e for high-speed milling.