Evaluation of Operability in Tele-operation Control of a Hydraulic Cylinder by the Packet Compensation Method

Abstract

Because of their small size and high output, hydraulic systems are widely used in industry as large processing machines and civil engineering machines at various sites. The purpose of the present study is to establish a tele-operation control technology for on-site operations by applying high-speed communication via TCP/IP to control hydraulic cylinders using a network backbone infrastructure that has recently been upgraded to have high bandwidth. In tele-operation technology using IP networks, packet delays, jitter, and packet losses during communication can cause deterioration of control performance. In the present study, we developed a tele-operation hydraulic control system considering the reaction force, and verified the operability of the compensation methods for packet delay, jitter, and packet loss that occur during communication using NIST Net, a network emulation tool. In addition, subjective evaluation of mental burden was conducted using the NASA Task Load Index (NASA-TLX), which can quantify the mental workload of operators. The results show that the application of packet compensation is effective in improving the communication quality of the network, reducing the calculated workload weight score by NASA-TLX, and reducing the overall mental workload of the operator.

Keywords

• hydraulic cylinder
• ip network
• reaction force
• packet compensation