Kollmorgen provides high-performance, ultra-reliable motors, drives, linear actuators, AGV control systems, and automation platforms for leading machine builders.
Square Robot, a leader in robotic inspection of above-ground storage tanks for diesel, gasoline, kerosene, oils, and other substances, needed compact and efficient thrusters for a submersible robot designed for in-service tank inspections.
By advancing its robotics, data collection, and data-processing capabilities, Square Robot enables inspections to be conducted without taking tanks offline, helping ensure structural integrity and operational safety.
Challenge
The submersible robot relies on eight thrusters to achieve six degrees of navigational freedom. An off-the-shelf thruster proved unsuitable due to material incompatibility with gasoline and related petrochemicals. Square Robot’s engineering team turned to Kollmorgen for its expertise in specialized motion solutions.
The project required the robot to be:
- Small enough to pass through narrow access points originally intended for human entry
- Agile enough to navigate around columns and internal structures for complete inspection coverage
- Adaptable for use in fluids with significantly different weights and viscosities
- Energy-efficient to support inspection operations lasting eight or more hours on one battery charge
Solution
To deliver the needed functionality, Kollmorgen supplied eight compact KBM frameless servo motors housed within nitrogen-filled pressure enclosures using dynamic seals.
The sealed pressure housing prevents contact between the KBM windings and tank fluid, avoiding the accumulation of ferrous debris, an issue with earlier designs where the motor windings were directly immersed. Built-in Hall sensors provide precise velocity control, enabling movement down to zero speed when required.
Results
The tailored KBM motors deliver consistent thruster performance in a wide range of fluid densities and viscosities. Hall sensor feedback allows precise velocity control, including accurate positioning of the scanning mechanism within half an inch of the tank wall. The motors’ robust construction supports reliability in the harsh conditions found inside fuel storage tanks.
Paired with Square Robot’s chosen drive system, the motion solution supports efficient performance across the full spectrum of speed and torque demands, allowing for inspection missions lasting eight hours or more on a single battery cycle.
Importantly, these performance enhancements are based on Kollmorgen’s commercial-off-the-shelf KBM servo motor platform, which secures ongoing manufacturability, product availability, and cost-effectiveness for Square Robot’s operations.
Charles O’Connell, Director of Mechanical Engineering, Square Robot, commented, “The integration of a frameless motor into Square Robot’s propulsion system was an incredible achievement for the team. We’ve been researching and developing technology to address the challenges that gasoline and other low-flashpoint materials bring, so it was great to collaborate with Kollmorgen and leverage their motor expertise during this successful SR-3 project.”
