But at that time Yan was unsure of exactly what the patents covered, and after half a year of research he invested over NT $ 10 million into product development. He sent his prototype, equipped with infrared sensors similar to Roomba's, to an American lawyer to check whether it would violate any of iRobot's patents.
然而，當時燕成祥並不確定倫巴已取得哪些專利，鑽研半年後，他投入上千萬元開發新產品，採用與倫巴類似的紅外線感測裝置，並將設計出來的「趴趴走」吸塵機器人原型寄給美國律師，請對方研究是否牴觸倫巴專利。