Simultaneous Transmission Method of Power and Information Using Hoist Ropes for Mobile Crane PLC

In recent years, mobile cranes have been larger, and enhancements of various safety devices and assist functions have also been demanded. The author has been proposing to use a hoist rope to equip the assist devices on a hook and to communicate with a device at the boom tip. Although it was reported that the hoist rope was suitable to perform high speed communication of 70Mbps using HD-PLC modems, the means to supply power to the modem equipped on the hook has been unresolved. In this paper, a simultaneous transmission method of power and information through the hoist rope has been proposed. Considering the EMC regulation, it is proposed to use two bands of from 1 to 10 kHz for power transmission and 150kHz or more for information transmission by G3-PLC. A channel modeling method for these bands was studied, and it has been concluded that the transfer functions were in good agreement with the measurement results. When the loop length of the hoist rope was 29.4m and 91.6m, the power transmission efficiency was 0.35 and 0.15, respectively. These values were promising as a result of the first step. It has also been confirmed that even if the G3-PLC modems shared a signal coupler for power transmission, both systems did not interfere with each other.