To hit a 22-second takt time and eliminate ergonomic risks, ACS delivered an automated assembly line with turnkey robotics. This vision-guided solution optimizes home appliance manufacturing by boosting safety and ensuring high-speed, defect-free production.
A major appliance manufacturer was concerned about the safety of its washing machine assembly line. Operators manually installed components through repetitive, taxing motions, resulting in injuries and reduced productivity.
To address both issues, the company launched a project to automate the line. It started with the portion where workers install balance rings, outer rings, and agitators. Besides improving safety, the manufacturer aimed for a 22-second takt time for each unit to pass through the automated assembly line spur and rejoin the main line. The tight space on the existing production line left minimal room for an enclosed, robot-operated line, requiring a tightly engineered solution.
A supplier to the manufacturer recommended ACS for the project, citing its success in providing turnkey robotics and automated solutions for complex home appliance manufacturing challenges. ACS engineers developed a concept that the manufacturer used as the basis for a competitive bidding process. After exploring alternative concepts and pricing, the company returned to ACS to implement its original concept, citing its clarity and cost-effectiveness.
ACS delivered an enclosed automated assembly line with a machine-driven roller conveyor and three synchronized robots. The ACS solution moves each tub from the main assembly line to the automated portion. Pneumatic chain lifts, positioned below the main line rollers, rise to push the washing machine tub forward wherever the line has a 90-degree turn.
At the first station, a robot installs the balance ring it takes from one of the two vertical storage towers designed and fabricated by mk North America. The tub advances to the second station, where a second robot installs the outer ring taken from the second tower. At the last station, a third robot retrieves an agitator from an mk VersaFlex accumulating pallet conveyor and installs it. This turnkey robotics system returns the completed tub to the main assembly line via pneumatic chain lifts and directional conveyors.
Three Yaskawa GP180-120 robots operate in coordinated cycles to maintain the system’s 22-second takt time, operating through MLX control logic on an Allen-Bradley PLC. Each robot works on a different tub as the conveyor indexes forward. Two robots handle the separate ring installations at the first two stations, while a third robot inserts the agitator at the final station.
Ten Cognex cameras provide real-time vision feedback to ensure precise alignment and accurate part placement in this home appliance manufacturing environment, putting nonconforming parts into a reject bin. The PLC synchronizes robot and conveyor movements, timing all stations to release together. This precisely managed sequence minimizes downtime and enables in-line quality inspection.
The ACS team designed the system with layered safety features that eliminate ergonomic risks and protect operators and equipment. Robots operate within cubic safety zones to prevent collisions. The first two robots share a single controller, enabling them to maintain real-time positional awareness and avoid interference in the shared reject space. Programmed virtual barriers further protect infrastructure by restricting robot motion within safe limits.
Interlocked doors prevent physical entry while the automated assembly line is active. Two pairs of vertical towers double as part storage and safety barriers, forming part of the enclosure. Each holds up to 20 rings for batch loading. As the robot pulls from one tower, the operator restocks the other from outside the cell at an ergonomic height. This turnkey robotics design avoids interference risks and keeps production moving.
Likewise, an operator places agitators on an accumulating conveyor from outside the enclosure, which the third robot accesses from within its safety zone.
Push-button controls at each station enable operators to load and release parts. They use a centralized HMI to start or stop the system, monitor production flow, and make manual adjustments.
ACS designed a compact, vertically optimized system that required no structural changes. To maximize reach while minimizing footprint, the engineers lowered the conveyor and elevated the robots. The two pairs of vertical part towers, enabling high-density component storage and delivery, also contribute to space efficiency in home appliance manufacturing.
This robotic system delivers measurable improvements in safety and productivity, meeting all the manufacturer’s goals. By eliminating manual installation tasks, it removed workplace injury hazards. The synchronized robotic operations achieve the 22-second takt time while reducing variability and defects through vision-guided precision. The manufacturer now has a faster, safer assembly line while increasing quality.
With its modular design, the assembly spur was seamlessly integrated with the existing line, keeping production running during installation and testing.
The manufacturer and ACS collaborated to refine concepts, troubleshoot challenges, and execute a solution based on ACS’ original design vision. The result was a sophisticated robotic solution within strict space and budget constraints. This approach not only delivered strong results but also laid the foundation for future assembly line automation.