TIERA - LUT Mobile Assembly Robot
We needed to identify a way to conduct assembly and repair operations in hazardous and dangerous environments where humans cannot operate.
We designed and developed a special mobile robot that can sense, navigate, and monitor its surroundings and conduct repairs and assembly tasks in inhospitable areas.
Link to the Facebook of the robot: https://www.facebook.com/TIERA-LUT-Mobile-Assembly-Robot-137769156592742/
Engineering Solutions to International Challenges
In 2011, an earthquake off the Pacific coast of Japan triggered a powerful tsunami that caused a major disaster at the Fukushima nuclear power plant. The tsunami disabled the emergency power to the reactor cooling systems, which led to three nuclear meltdowns, chemical explosions, and the release of radioactive material.
To prevent further catastrophe, 50 volunteer technicians ventured into the exclusion zone surrounding the power plant to stabilize the reactors. These brave individuals, known as the ‘Fukushima 50', had to perform simple repair work, including closing valves, in one of the most hazardous environments on Earth. The exposure to extreme radiation could have serious ramifications on their long-term health.
Like many people around the world, our team felt inspired by the Fukushima 50. We admired their bravery, yet felt that modern mechatronic systems could remove the need for humans having to perform menial repair work in such hazardous environments. This became the inspiration for our work on the mobile assembly robot.
TIERA is a versatile, mobile robot that can conduct repair and assembly operations in hazardous areas. The functionality and composition of the robot are defined by the tasks we expect it to perform and the harsh environments we expect it to work in. We considered many environmental factors in our design including radiation, corrosion, toxicity, explosion, biohazard, high voltage, and extreme temperatures.
The list of robot features and sensory systems are as below:
- Mobile Omni traction system (4 independent servo motor gearbox )
- Two serial robot arms
- Two Gripper hands
- Movable head and neck based on pan and tilt methodology
- Two head camera capable of 3D streaming and pattern recognition
- Two hand camera
- One 360 camera capable of communication with VR glasses
- Light Detection and Ranging (LiDaR)
- Inertial Navigation System
- Ten sonar distance sensors
- Quadcopter for aerial view (hidden inside the robot structure)
- Repair and assembly tools such portable electrical screw driver, drill, cutter, solder, . . .
- Force feedback joysticks
- Wi-Fi and 4G communication
- Robot air-conditioning system
- 3D screening
- Smart power system
- NI cRIO central control system
- Novel NI LabVIEW + ROS methodology
Our Robot Central Control System
The main feature of TIERA's central control system is integration of cRIO Real-time Linux with the flexibility and features of ROS, which generated many novel features for our robot.
Digital communication plays a vital role in any advanced robot. It can include communication between an operator and a robot, between a robot's control devices and its peripheral hardware, between different programmatic nodes being executed by a robot's processor, and much more.
A local net allows the transmission of control messages for movement of robot sections, which are published into ROS topics by the main station. Then an onboard computer subscribes to topics and reads messages. From the computer installed on the robot, a signal spreads to each device according to instructions. Signals from a remote control reach the main station, and then they are processed in ROS and sent to the Advantech by WiFi.
We calculated direct and forward kinematics in ROS on the main station and generalized coordinates for control reach controllers inside mechanisms. As explained before, the robot sections operate under control of ROS and we programmed some of them using LabVIEW software. We can merge code from each part together into the one control program, which monitors and controls every device of the robot. We placed controllers of those devices into the one local network, which makes communication between all of them possible.
We can integrate the CompactRIO controller into the whole robotic system using the LabVIEW library to publish information into ROS topics in the same local net. Tufts University developed this library, which is freely available on the LabVIEW Tools Network. The LabVIEW application runs on the CompactRIO and on the main station at the same time. The user interface translates information from sensors, and we can use the same information after publishing into topics at the same time for other sections of robot. For example, wheels must be stopped if distance to an obstacle is less than a critical threshold.
The ROS and LabVIEW collaboration empowers us to use different types of devices and controllers connected to the one network. We must organize the system in the same network for design of the united system of various groups of hardware and software.
The Future of TIERA
We are making rapid progress with the TIERA robot. All of the robot's systems are fully operational, and we have tested them individually. We are now commencing the first full system tests and planning further upgrades.
The versatility and modularity of the TIERA and its CompactRIO controller means that it is not limited to assembly and repair in hazardous environments. We can quickly repurpose the robot for multiple industries and other spheres of human activity, including:
• Hospitals: drug delivery, transportation of food and medicine
• Cleaning: automatic cleaning of large areas, such as supermarkets, airports, industrial sites
• Warehouses, Distribution, and Logistics: efficient relocation of materials from stocking shelves to order fulfillment zones
• Industry: assembly, materials delivery
• Military and Security: diffusion of explosives, providing vision and monitoring in dangerous areas
• Mining: exploration of the mines, operation in hazardous areas
• Ship Yards: performing welding and cutting
• Research: volcanic research, Antarctica and Arctic research
Prof. Heikki Handroos
Tel. +358 40 510 7599
Dr. Hamid Roozbahani
Tel. +358 40 678 3948
Lappeenranta University of Technology
P.O. BOX 20 / PL 20
FI-53851 Lappeenranta, Finland