The toolpath smoothing and feedrate scheduling in computer numerical control (CNC) system are critical for high-speed and high-precision machining. The existing toolpath smoothing schemes perform insufficiently in raising the smoothness of feedrate trajectory. Aiming at increasing the smoothness of toolpath and reducing machining vibration, a smooth S-curve acceleration/deceleration(AD) control algorithm based on the jounce limited profile is proposed. In the paper, for the curves that do not meet the complete smooth S-curve acceleration/deceleration conditions, they are divided into three cases according to the length of the curve and give a detailed calculation formula. All trajectory parameters are derived with the analytical algorithm to ensure an acceptable computational complexity. Finally, a series of numerical simulations and actual machining and measurement experiments are conducted, and the simulation and experimental results have showed the good performance of the proposed algorithm compared with previous method both in motion smooth and surface quality.

feedrate planning; jerk-continuous feed; incomplete smooth ac; deceleration; surface roughness