Tunnel explosive loading, once carried out by five workers exposed to the risk of cave-ins, can now be done by a single operator from 50 meters away, feeling every sensation as if right there at the face. A technology that reproduces the sense of touch remotely is transforming real construction sites.

What is Real Haptics?

Real Haptics is a force-feedback technology developed by Keio University's Haptics Research Center. It transmits, in real time, the tactile information a robot senses when it touches an object, such as hardness, softness, and elasticity, to an operator in a remote location.

Established in 2014, the Haptics Research Center, led by Specially Appointed Professor Kohei Onishi and Associate Professor Takahiro Nozaki, has advanced the industrial application of this technology. Conventional remote-controlled robots provided only video and audio, but adding Real Haptics gives operators a sense of touch, making delicate work possible.

The Dangerous Reality of Mountain Tunnel Construction

One of the most hazardous tasks in mountain tunnel construction is explosive loading and wiring at the face (the excavation surface). The face is constantly at risk of spalling, the sudden fall of rock, and many of the most serious accidents occur there.

The work involves packing explosives into blast holes roughly 5 cm in diameter and 1 meter deep, then connecting detonator wires. Because it involves handling explosives, delicate force control is essential, and until now it could only be done by hand. While heavy-machinery tasks such as installing steel supports have grown more automated, explosive loading was technically difficult and long resisted unmanned operation.

How the System Was Developed

Obayashi Corporation and Keio University have pursued this research using Real Haptics as part of NEDO's (New Energy and Industrial Technology Development Organization) Program to Support Young Researchers through Public-Private Collaboration.

In September 2023, they demonstrated the automated explosive loading system's proof of concept in laboratory tests. In 2024, field tests at a tunnel construction site in Nagano Prefecture achieved actual explosive loading and blasting via remote control, from a point 30 meters from the face and from 320 meters outside the tunnel.

Then, on January 20, 2026, they announced that a supply device for primer explosives had been added to the system, achieving unmanned explosive loading with no workers directly beneath the face. Work that once required five people can now be carried out continuously by a single operator in a control room 50 meters from the face.

How the System Works

The automated explosive loading system consists of a loading robot mounted on the arm of a drill jumbo (a boring machine). A remote controller in the operator room and the loading robot at the face are linked through Real Haptics, transmitting tactile feedback in both directions.

Operators work while watching monitor footage of the area around the blast holes. The feel of the robot arm gripping an explosive and the resistance as it is inserted into a hole are transmitted to the operator's hands in real time, so even subtle differences, such as whether a rod has struck a hole or merely grazed it, can be told apart.

The newly added primer supply device uses a belt-conveyor system to feed multiple primer explosives in sequence. A mechanism to prevent wires from tangling was also added, enabling continuous loading into multiple blast holes.

Future Prospects and Applications

Obayashi Corporation and Keio University plan to work on simultaneous operation using multiple loading robots, coordination with autonomous heavy machinery, and automation of the wiring work. By having each task learned autonomously, they ultimately aim to make the entire tunnel excavation process unmanned.

Real Haptics has applications well beyond tunnel construction. When applied to hydraulic construction machinery, it has been shown to let heavy equipment gently grasp fragile objects. Uses in remote surgical assistance in medicine and in rescue robot operation at disaster sites, among other fields, are also anticipated.

Impact on the Construction Industry

Japan's construction industry faces severe labor shortages and an aging workforce. According to the Ministry of Land, Infrastructure, Transport and Tourism, more than one in three construction workers are 55 or older, while only about 10 percent are under 29. Making dangerous tasks unmanned is expected to play a crucial role in attracting younger workers and passing on the expertise of veteran technicians.

Real Haptics is not merely a substitute for human labor. It has the potential to extend human senses and enable safer, more efficient ways of working. The digitization of touch is beginning to open up the future of the construction site.

In Japan, innovations like this are being adopted to improve construction-site safety and ease labor shortages. How far has the unmanned or remote handling of dangerous work advanced in your country? We'd love to hear about technology adoption in your construction industry.

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