| This study used combined method of experiment and simulation to measure the six common grass seeds’ (white clover, datian baimai root, red clover, lentils, alfalfa and sainfoin) basic physics (seed coat thickness, the density of seeds, grains) and contact mechanics parameters (static friction coefficient and friction coefficient). Then the data were used to develop the grass seed broken sleep machine. The seed densities of the six herbage species were 1.082, 1.212, 1.210, 1.246, 1.302 and 0.658 g·mL-1, respectively, and the 1000-seed weights were 0.581, 1.254, 1.252, 1.508, 2.074 and 28.556 g, respectively. The static friction coefficients between grass and steel were 0.406, 0.425, 0.513, 0.547, 0.494, 0.472, and those between grass and glass were 0.386, 0.397, 0.489, 0.514, 0.473, 0.703, respectively. Based on EDEM simulation, the rolling friction coefficients between forage seeds were 0.451，0.302，0.502，0.360，0.250 and 0.410, respectively. |