Mitsubishi Heavy Industries Validates Explosion-Proof Robot for Refinery Inspections

Mitsubishi Heavy Industries, Ltd. (MHI) has successfully completed a running test of its prototype EX ROVR, an autonomous plant inspection robot engineered with explosion-protection features. The test was conducted jointly with JXTG Nippon Oil & Energy Corp. at the Mizushima Refinery in Kurashiki, Okayama Prefecture, Japan.

The EX ROVR is purpose-built to operate safely in environments where flammable gases are present. Its explosion-proof design prevents the robot itself from becoming an ignition source — a critical requirement in oil refinery and petrochemical plant settings where even a small electric spark or excess heat could trigger a fire or explosion.

What the Running Test Demonstrated

During the trial at the Mizushima Refinery, the EX ROVR demonstrated the following capabilities:

• Autonomous multi-floor navigation: The robot moved independently through several floors of a confined plant building, including navigating staircases — a significant challenge for wheeled or tracked inspection platforms.
• Multi-sensor data collection: The EX ROVR gathered readings from its onboard sensor suite during the patrol run, simulating the data-collection tasks required in routine plant inspections.
• Automated docking and charging: The robot managed continuous operation by autonomously returning to a docking station for recharging, enabling extended, uninterrupted patrol cycles without human intervention.

The test confirmed that the prototype meets the baseline functional requirements for conducting routine patrol inspections and responding to emergency situations at JXTG Energy facilities. MHI and JXTG Energy are continuing to analyze test results to identify remaining issues and drive further improvements before commercialization.

Explosion-Protection Standards and Safe-Area Classification

A defining feature of the EX ROVR is its compliance with internationally recognized explosion-protection standards:

• Japan’s explosion-proof guidelines — the domestic regulatory framework governing equipment used in hazardous industrial environments in Japan.
• ATEX — the European Union directive covering equipment and protective systems intended for use in potentially explosive atmospheres.
• IECEx — the International Electrotechnical Commission’s scheme for certifying explosion-protected equipment, widely adopted globally.

Together, these certifications allow the EX ROVR to be deployed safely in Zone 1 environments — areas where an explosive gas atmosphere is likely to occur periodically during normal operation. This is a more demanding classification than Zone 2, making Zone 1 compliance especially relevant for active refinery process areas.

Technology Lineage: From Nuclear to Petrochemical

MHI’s development of the EX ROVR draws on its prior experience with robotics in extreme and hazardous environments, including support roles in nuclear plant accident containment. Applying ruggedized, safety-critical robotics expertise to oil and gas inspection reflects a broader industry trend of repurposing heavy-industry automation technologies for plant safety applications.

Path to Commercialization

The Mizushima Refinery test represents an early but meaningful milestone. MHI plans to conduct additional tests and demonstrations across a range of plant environments with the goals of:

• Increasing inspection coverage density — ensuring the robot can reliably check a greater proportion of plant assets per patrol cycle.
• Enhancing overall safety and robustness under varied operating conditions.
• Pursuing full commercialization of the EX ROVR platform for use across the refinery and petrochemical industry.

For plant operators, autonomous explosion-proof inspection robots represent a significant shift: routine hazardous-area patrols currently performed by human technicians could be handed to robots, reducing personnel exposure to dangerous environments and enabling more frequent, consistent data collection.

More information about MHI’s robotics and industrial automation work is available at www.mhi.com.