Robots Support Bullet-Train Maintenance
EP Editorial Staff | January 21, 2019
A state-of-the-art approach helps Japan’s iconic high-speed rail system safely transport more than 163-million passengers annually.
JR Tōkai, Japan’s central railway-operating company, keeps the world’s most heavily traveled high-speed rail system running safely and on time with state-of-the-art technologies and processes.
When it began passenger service in 1964, Tōkaidō Shinkansen was the first high-speed rail system in the world. It was a modern marvel and quickly became one of the most iconic images of modern Japan. Today, it transports more than 163-million passengers annually between major Japanese cities such as Tokyo, Nagoya, and Osaka at speeds approaching 285 km/hr (177 mi/hr), and, by a wide margin, is the most heavily used high-speed transportation system in the world.
The term “bullet train” is often used to describe the Tōkaidō Shinkansen system due to the long, sleek noses of the lead cars, which have been designed to achieve optimal aerodynamics and mitigate noise. The trains are known for being an incredibly safe mode of transportation, without a single passenger ever having been killed or injured in an accident.
To keep the system running at peak efficiency, the cars undergo regular maintenance at a factory in Hamamatsu. Since 2010, JR Tōkai, Nagoya (global.jr-central.co.jp/en/), the main Japanese railway-operating company, has been managing a major upgrade at the Hamamatsu facility, creating state-of-the-art maintenance processes to serve the growing base of cars.
One of the more sophisticated process upgrades has been the installation of six IRB 6650S robots from ABB, which has North American headquarters in Auburn Hills, MI (abb.com). These six-axis industrial robots are used to sand the noses of the lead train cars prior to repainting. It’s an important task. Due to wear that occurs on the noses from driving the high-speed trains through a range of elevations and four distinct climate seasons, they’re sanded and repainted every 36 months or every 1.2 million km (approx. 745,000 mi.). This sanding makes the new paint adhere better and, in turn, withstand the constant exposure to high-speed air pressure.
Due to the streamlined and complex shape of the car noses, for many years the sanding process was performed manually. The task used to require six people and take more than three hours to complete. With the new system, cars are mounted on ABB IRBT 6004 motion tracks that provide access to all areas of the car noses at angles necessary for optimum sanding. The combination of motion tracks and six robots has decreased sanding time to about 45 min.
In addition to providing an improved sanded surface, the robots have allowed the manual sanders to be relieved of a very difficult, ergonomically challenging task, and moved to safer, less physically difficult car-maintenance jobs.
ABB’s Integrated Force Control technology is integral to the high quality achieved by the robotic sanding process. Force Control, software installed in the IRC5 robot controller, leverages real-time tactile sensor feedback to handle process variations with the sensitivity of a human hand. This allows the robots to react to their surroundings and deviate from their programmed speed or path, providing superior performance while reducing programming time as much as 70%.
In the process of sanding the complex nose surface, the force technology fine-controls the torque applied to the surface to attain constant finish quality, making it possible to automate the delicate task that previously required manual labor. This is particularly important in allowing the robotic sanders to make subtle adjustments necessary to seamlessly handle three-dimensional variances in the shapes and contours of the train noses. Cars from multiple vendors run through the system and each shape is slightly different, with as much as a 100-mm variance in extreme instances. With Force Control, the robots make real-time adjustments without requiring further programming.
Force Control and the IRC5 controller were able to be integrated with the Panasonic sanding brush and rotation mechanism attached to the robot arms (Panasonic Environmental Systems & Engineering Co. Ltd, Suita, Japan, panasonic.co.jp/es/peseseng). This integration led to simplified control, greater safety, full process automation, and improved quality.
With ABB’s RobotStudio simulation and offline programming software, the ABB service team was able to support the Hamamatsu operations team, quickly handling minor process adjustments after the system was installed. RobotStudio was also instrumental in programming the motion of each robot to collaboratively reach every part of the robot noise without missing spots or duplicating efforts.
All six robots are equipped with Foundry Plus protection that makes the entire robot, from base to wrist, IP67 compliant for trouble-free operation and corrosion resistance, especially beneficial in the harsh wet-sanding environment.
A member of the ABB Robot System team in Japan explained, “We are proud that ABB’s unique technology, including Integrated Force Control and six-axis, Foundry Plus robots are supporting the sustainable operation of Tōkaidō Shinkansen, the first and best in world-class, high-speed rail. We are also very pleased that we had the opportunity to collaborate with Panasonic Environment Engineering in providing the optimal robotic sanding solution.” EP
For more information about ABB Robotics, click here.