| 摘要: | 本論文的目的是假設已經經過攝影機得知對手來球方向、速度、位置後推測乒乓球機器人擊球的位置、方向、擊球後球到對方桌面的預計落點位置與擊球時為了達到擊球後的球速所需要的揮拍角速度並得出球拍的力與力矩。本論文所針對的是三自由度機械手臂，而且假設揮拍是繞垂直地面的軸旋轉，針對各種不同來球位置，來球的球速與方向，且預計擊球後球到對方桌面的落點位置後本文利用線性動量與衝量原理、角動量與角衝量原理、恢復係數估計、尤拉方程式、牛頓第二運動定律、假設球在撞擊球拍面時是以鏡射的方式進行下，可以推測出所需要的揮拍角速度。本論文提出擊球前與擊球後角速度相等的模式、以一點固定之特例情況的模式和估計擊球後球的旋轉方向並運算得知的模式並比較結果。
In this thesis we deal with a three-degree-of-freedom spherical table tennis robot. It is assumed that the hitting position, direction and velocity of the coming ball are observed by the camera. The position the ball will drop on the table after the robot hit the ball is also chosen. In this research the hitting position of the robot, hitting direction, and the swing velocity of the paddle so that the ball will fall on the desired location are estimated. Also we may calculate the forces and moments applied to the paddle during swing. The paddle swing is simplified to be a rotation about the axis normal to the ground. Also we assume that rebound of the ball on the paddle is similar to reflection of light from a mirror. The principle of linear impulse and momentum, the principle of angular impulse and momentum, the value of coefficient of restitution, and Newton’s second law of motion are used to estimate the swing velocity of paddle. In this thesis we propose three methods for estimation. The first method is based on the fact that the swing motion is rotation about a fixed-point. In the second method, it is assumed that the swing velocity remains the same after impact. The third method we restrict the resultant moment on the paddle is in the direction of swing. Finally, we compare the results obtained from the three methods. |