Trolley Navigation Assist
To understand how the Trolley Navigation Assist (TNA) works, it is important to first know what a trolley system is. A trolley system is a power delivery system that allows mining trucks to use electricity from fixed electrical infrastructure as their power source, rather than using a diesel combustion engine. The trucks connect to the trolley line via a pantograph and collect the energy needed to move the machines via this connection. However, it can be difficult for operators to connect successfully to the trolley line, given the small size of the target. Moreover, it can be difficult for operators to maintain a consistent travel path while connected to the trolley.
This is where the TNA can help.
The TNA leverages a mine site’s existing GNSS RTK base station and radio frequency identification (RFID) technology to identify the right time to automatically raise and lower the trucks’ pantographs and to steer trucks while connected to the trolley line. The onboard GNSS unit stores the location data of the trolley line and compares this to the position of the trucks. The TNA will then make steering corrections to keep the trucks aligned with the trolley line. The RFID technology is a secondary system that helps to control the pantograph and its connection to the trolley line. Once the system has been installed, the customer can create trolley navigation missions using a combination of the imported site survey imagery, landmarks known to the survey team, and the trucks’ overall operating area. The MPS allows the customer to designate different areas of the mine site as signifiers for when the TNA needs to take certain actions. Within the software, the customer can highlight which area on site is the “operation area” for the TNA and thus, when this system needs to come online. Inside that area, the customer can nominate the “hands off area” for when the system needs to notify the operator – via audible chime and visual cues on the TNA screen – to remove their hands from the steering wheel. This is when the TNA would take control of the truck and guide it to the appointed “starting area”, where the system will raise the pantograph to connect to the trolley line. The truck will then steer itself along the trolley line in the operating area until it reaches the place that the customer has designated the “ending area”. Here, the system will automatically disconnect the pantograph from the trolley line and alert the operator that it is time to take control of the truck once more.
Customers can allocate alternate access points along the designated trolley path to accommodate times when the operator needs to disconnect their truck from the trolley. For example, if the path is blocked due to a stalled truck or spillage, the operator can deactivate the TNA, travel around the blockage, and can reactivate the TNA at a predetermined alternate access point. Alternate access points can also be used in instances where trucks need to enter the trolley line from an intersection within the line. The TNA can maximise trucks’ time under trolley by ensuring that they are connected to the line properly and can automatically follow the trolley line’s path. This results in a reduction of the fuel consumed by the trucks. Further, the TNA can help to reduce the pressure on operators to keep the trucks perfectly in line with the trolley, thus ensuring increased efficiency and decreased operator stress and fatigue.