1. College of Mechatronic Engineering, Southwest Petroleum University, Chengdu, P.R. China
2. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu, China
3. Baoji Oilfield Machinery Co., Ltd., Chengdu, China
4. School of Mechanical Engineering, Southwest Jiaotong University, Chengdu, China
5. Engineering Training Center, Southwest Petroleum University, Chengdu, P.R. China