Tham khảo tài liệu 'climbing and walking robots part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Stair Climbing Robots and High-grip Crawler 83 Friction Characteristics of each Block For measuring the characteristics of the face material used for the crawler belt of a stairclimbing crawler the experimental device shown in Figure 17 was prepared. An aluminum block acts as a stair edge and presses against the measured soft material applying a sideways force. First the relationship between vertical force and vertical deformation when the experimental edge is pressed was measured. Next for measuring the grip ability against the stair edge vertical and horizontal forces were measured when slight slippage occurred due to a horizontal force during vertical loading. The equivalent frictional coefficient for each vertical loading is calculated as Horizontal Load Grip Force EquivalentFriction coefficient -------------------------- 1 The equivalent frictional coefficient is measured for cases of increasing vertical load and decreasing vertical load from the maximum load because of the hysteresis characteristics of the materials. The measured materials were the newly developed powder-filled block a urethane rubber block with approximately the same vertical deformation a urethane rubber block in the tube used in the newly developed powder-filled block and the tube itself. The size of these experimental materials is the same as that of the powder-filled block as shown in Figure 5 90L X 50W X 30H 100 g . In order to examine the change in the characteristics with the diameter of the powder the blocks were filled with aluminum balls of 3 mm in diameter and plastic balls of 6 mm in diameter. Fig. 17. Experimental system Measurement Results of Deformation First the results of a comparison of the deformation between the urethane rubber block and the powder-filled block are shown in Figure 18. The same deformation characteristics are observed with an increasing vertical load. However with a decreasing vertical load the powder-filled blocks retain their previous deformation
