The kinematics and dynamics characteristics of the digging-expanding motion of forelegs in mole crickets

Yan Zhang(1), He Huang(2), Yueying Zhu(1), Junxia Zhang(1)

1 Tianjin Key Laboratory of Integrated Design and On-line Monitoring for Light Industry & Food Machinery and Equipment, College of Mechanical Engineering, Tianjin University of Science & Technology, Tianjin 300222, P. R. China;

2 Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300192, P. R. China.

The high-efficiency excavating of mole crickets is related to the excavating motion characteristic and force action mode. In this study, the expanding force of forelegs was measured by using the self-made test equipment, and the two-dimensional motion during burrowing was captured using a high-speed camera. The results showed that the forelegs of mole crickets employ a unique digging-expanding excavating pattern, which consisted of foreword digging and horizontal expansion. In this excavating motion, the max included angle between two forelegs was about 47.4, and the relative average expanding force was about 0.84N. The kinematics and dynamics parameters were analyzed and a preliminary model of the digging-expanding motion was established. This study can provide new insight of tunnelling mechanism design.