Why can't a robot cross the 20mm threshold?

(1) In real life scenarios, due to the shape of the threshold, the width, the angle of the robot climbing up the threshold and other factors, the robot climbing effect will be affected, you can buy an auxiliary climbing plate from Ecovacs mall to help climbing (20mm data from Ecovacs lab);
(2) The drive wheels may be stained with pet and human hair during operation, and it is recommended that you clean them regularly, otherwise it will also affect the robot's climbing performance;