Motion Control

Manufacturers are increasingly automating their warehouse operations to increase efficiency and productivity, reduce operational costs, and improve accuracy and safety.

The latter, in particular, is a driving force behind automated material handling. For example, according to the U.S. Bureau of Labor Statistics, forklifts were responsible for 15,480 nonfatal workplace injuries in the two-year span from Jan. 1, 2021, to Dec. 31, 2022.

The situation at Nidec Drives was no different. Over the past five decades, our U.K. assembly plant has undergone significant expansion and transformation. To maintain quality standards and become more efficient, we needed to automate our material handling process.

We had been using forklifts to transport parts and raw materials from the warehouse to the assembly plant. Inside the factory, workers moved parts up and down three production floors. The process was time-consuming and labor-intensive. Given the complexity of interlinking different levels within the factory, a custom material handling system would be essential.

“We conducted value stream mapping, and by taking an overview of production, preparation and process, were able to formulate a plan for a conveyor and lift system that would move raw materials around the factory, where they needed to be, and when they needed to be,” says Jamie Evans, warehouse and distribution manager at Nidec Drives.

Intralogistics Experts

With that decided, all we had to do was find the right system. Evans embarked on a mission to find the ideal vendor for implementing the latest advancements in automated warehouse technology. Our company operates under the “Nidec Way,” a business management principle created by our founder, Shigenobu Nagamori. This principle emphasizes excellence through lean management strategies, such as just-in-time inventory management. Continuous improvement is fundamental to our operations, so we needed a partner who could design a solution that embodied these dynamic strategies.

“We invested significant time in researching the right supplier to collaborate with us on achieving the optimal solution,” says Evans. “Ultimately, Invar Systems emerged as the clear frontrunner.”

Based in Atlanta, Invar Systems specializes in technology for intralogistics and warehouse management. Invar’s core product is a fully developed but highly customizable software platform that has the capabilities of both a warehouse control system and a warehouse management system. The systems integrator also designs and implements automated storage and retrieval systems; picking and fulfillment systems; and conveyor and sortation systems from multiple OEMs.

Invar proposed a custom material handling system tailored to Nidec’s needs and values. Since Invar is not affiliated with any one supplier, the integrator selected only the best elements for the project. Ironically, many of the machines in Invar’s automated system run on the Control Techniques variable speed drives that Nidec assembles at the factory! By combining teamwork, top-quality components, and incorporating Control Techniques variable speed drives, Invar successfully completed the project ahead of schedule and within budget.

“This achievement wouldn’t have been possible without the exceptional collaboration and support from Nidec,” says Sham Jama, project manager at Invar.

Invar’s tote transportation system consists of approximately 300 meters of powered roller conveyors from Interroll Group and three lifts from Nerak Systems Inc., spread across three buildings. The system in the main assembly area features two tiers for goods coming in and goods going out.

Each tote has its own “license plate number” (LPN), which is scanned at each workstation. Once a worker loads or unloads a tote, it is automatically transported to the next stop, whether it’s another workstation, a storage area, or the assembly line. Workers can also use touch-screens to select the tote’s next destination.

A key aspect of the system is its ability to operate on demand, halting completely between tote loads. This saves energy costs and is expected to achieve a return on investment (ROI) in under a year.

Leveraging Control Techniques Products

Nidec’s Control Techniques drives are integral to the efficient stop-start nature of the system. For this project, two types of drives were used: three Unidrive units and eleven Digitax HD M750 units.

The Unidrive was selected for the lifts within the system. Unidrive offers exceptional control stability and bandwidth for all industrial motors. The Unidrive M702 variant features onboard Ethernet and dual STO inputs.

Several optional modules were fitted to the Unidrives. The SI I/O interface module provided additional input and output connections. The SI universal encoder module, which ensures positional accuracy by connecting to a rotary encoder on the motor, was also added. This module checks if the encoder’s value matches that of a second encoder measuring position with a laser; if the values align, the programmable logic controller allows the drive to run; if not, the system’s brakes are applied.

Nidec engineers also specified the PTi210 Easy Motion controller. With this module, there is no need for software development. It was simply plugged into the drive, then connected through PowerTools Studio software, enabling the creation of quick, simple and repeatable routines that the Unidrives in the conveyor execute repeatedly. The PTi210 is compatible with both Unidrive and Digitax HD M750 drives.

For single-axis motion with complex controls, such as the conveyor, the PTi210 and Power Tools software package is a cost-effective way to provide simple, fast and effective motion control. Users of all skill levels can configure, program, select functions, and set up parameters. This expediates the configuration, management, and long-term maintenance of the conveyor.

Finally, Nidec’s KI keypad was installed, allowing users to adjust drive parameters while displaying key information, such as current draw, speed or faults.

The Control Techniques Digitax HD M750 servo drive series complements the Unidrive range by providing maximum servo performance in a compact package. Digitax HD M750 is optimized for high-dynamic applications, offering flexibility in both stand-alone and modular configurations. This drive delivers full servo control, plus open-loop permanent magnet motor and induction motor control, across four functionality levels: EtherCAT, MCI machine control, Ethernet, and the flexible Base servo drive.

The Digitax HD M750 drives chosen in this project were used for controlling the drum motors along the powered roller conveyors, and on the belt conveyor’s incline and decline sections. This drive was selected due to its compact size, high power density, dual STO, and ability to communicate on the Profinet network.

As a full machine control solution, the Unidrive works in harmony with three Leroy-Somer IMfinity three-phase induction motors; one on each lift of the conveyor. Provided by Nidec ACIM, IMfinity motors reach premium efficiency up to IE4; maximizing energy savings, enhancing performance, and optimizing the productivity of the lifts. The robust design of the IMfinity range of Leroy-Somer motors ensures guaranteed performance and lower maintenance costs. To work seamlessly with the Unidrive, the IMfinity motors have winding protection as standard, thermal reserve for maintaining the rated torque over an extended speed range, and a metal support plate to reduce electromagnetic noise.

Impact and Future Developments

The installation of the new conveyor and lift system was completed in just four months. Since its implementation in April 2024, the impact on productivity and staff morale has been significant. The team can now retrieve parts without physically moving and accessing bulk materials, production bottlenecks have been eliminated, and individual efficiencies have markedly increased.

“The conveyor is just the latest step in our ongoing efforts to enhance our manufacturing facilities,” Evans explains. “We are always exploring the next steps we can take to improve efficiency and quality, and we look forward to further growth.”

“At Invar, we install a legacy for our clients,” Jama adds. “We work hard to meticulously maintain every element of our system through maintenance, communication and strong connections with our customers. This project ran so smoothly with the help of Jamie and his team; I believe this marks the beginning of a long and fruitful relationship.”

Looking ahead, Nidec Drives is considering the implementation of autonomous mobile robots (AMRs) at the U.K. factory. AMRs address many challenges in high-mix manufacturing operations by independently navigating their environment, picking, sorting and transporting components. These robots enhance employee safety and allow the teams to focus on more complex tasks.

Nidec Drives will collaborate with Nidec Automation, which produces motors, motor control solutions, integrated drive solutions, and battery management systems for AMRs, to explore how these robots can further improve efficiency and quality at our assembly plant.

For more information on electric motors and variable speed drives, visit https://acim.nidec.com.

For more information on warehouse automation, visit www.invarsystems.com.