Hitachi Construction Machinery Co Ltd (HCM) has developed an Operator Assist System aimed at supporting the digging and loading operations of ultra-large hydraulic excavators for improved operational performance and says it will conduct a verification test at one of Rio Tinto’s mine sites in Australia from late March 2024.
Through the application of the Operator Assist System, HCM says mine sites will benefit from reduced operator burden, improved mine site safety, increased productivity and reduced fuel consumption. The conducting of testing on a site operated by the mining giant will demonstrate the practical application of the Operator Assist System and will help to improve the accuracy of the system going forward.
Mines producing iron ore, copper and other mineral resources are required to provide stable operations 24 hours a day, 365 days a year and the operators of ultra-large hydraulic excavators at these sites are tasked with efficiently digging material and repeatedly loading them onto dump trucks, while carefully avoiding contact and collisions with surrounding machinery. Therefore, developing solutions which proactively support operators by reducing their workload, while enhancing site safety and productivity is a critical issue for the mining industry to explore.
The verification test will be performed at one of Rio Tinto’s iron ore mines in the Pilbara region of Western Australia. Sensors, monitors and other equipment will be attached to a backhoe EX3600-7 ultra-large hydraulic excavator (operating weight of 360 t) to conduct a performance verification of digging and loading tasks by the Operator Assist System and verification of the usability of the monitor display installed in the operator cab.
Based on the verification at the mining site and through insights gained via collaboration with customers, such as through this partnership with Rio Tinto, Hitachi Construction Machinery aims to achieve practical application of the Operator Assist System in stages from 2025.
All of the functions of the Operator Assist System enable retrofitting support for the EX-7 series of ultra-large hydraulic excavator models EX2000-7 through to EX8000-7 (operation weight of 200 to 800 t), backhoe front specification machines to provide added value to customers for machines that they already own.
The Digging Assist function assesses the situation from the load on the hydraulic cylinder and the operation of the front attachment, detected by sensors to automatically improve control of the hydraulic excavator operation according to the situation. To efficiently excavate material, the amount excavated by each operation must be as optimal as possible. At the same time, when the bucket load during digging becomes excessive, the hydraulic circuit protection function activates to curtail additional digging force and intermittently redirect the operation of the front attachment. In this case, the load on the engine and the hydraulic system continues to be at the maximum level, which leads to decreased productivity due to lost work time and increased fuel consumption.
While experienced operators are able to judge the situation based on the movement of the front attachment and the sounds and vibrations emitted by the hydraulic circuit to reduce the cylinder load, inexperienced operators may be unable to skillfully achieve the same results. This function can automatically perform operations which reduce the cylinder load regardless of the operator’s level of experience.
The Loading Assist function automatically controls the front attachment when loading material excavated by an ultra-large hydraulic excavator onto the dump truck to help avoid collisions. Typically, the operator recognises the position, orientation and height of the dump truck body to turn the excavator upper structure and perform the loading work while operating the front attachment.
To avoid contact and collisions with the dump truck and surrounding structures during the loading work, the operator must combine the operation to raise the front attachment of the hydraulic excavator with the operation to swing the upper structure. This combined operation poses a high degree of difficulty for inexperienced operators and even experienced operators require a high level of concentration. Since this function automatically performs the operation to raise the front attachment, the operator can concentrate on just the swing operation, which reduces mental load on the operator.
In addition, the dedicated monitor installed in the operator cab of the ultra-large hydraulic excavator displays information such as the bucket payload and the hydraulic cylinder load of the front attachment, which helps the operator manoeuvre and assess the status of the machine.
Rio Tinto has been a longstanding, important partner company of Hitachi Construction Machinery and since August 2023, has been jointly conducting durability testing of the boom and arm for ultra-large hydraulic excavators.
Going forward, the Hitachi Construction Machinery Group says it will strive to solve customer issues as ‘a true solutions provider’ to help increase safety and productivity and reduce the life cycle cost of customer machinery through collaboration with customers.
