The Problem: A heavy truck manufacturer sometimes had components damaged during frame positioning. The damage could go undetected until after additional parts had been added, creating high rework costs. Trailing lines and hoses were a trip hazard.
The RedViking Solution: Battery-free rail-guided AGVs with operator-controlled lifts to position and transport the heavy truck frames for assembly. Remote controlled AGVs give operators greater control over part positioning to prevent damage to components.
Positioning process could damage assemblies
Here was our customer’s original process:
- Frames were transported to the line by large J-hooks
- Airbags were inflated to lift the frames onto an electric rail cart
- Operators transferred the frames from the rail carts onto 3-strand conveyors
- Frame components progressed throughout assembly, trailing cords and lines
- Where possible, operators inspected for damage from airbag inflation
There were multiple frustrations throughout this process. First, because the airbags left no room to finesse the frames into place, hoses and lines could come loose and be damaged. It was hard for the operators to see them, so the breaks could go undetected until after the frame had advanced and been built up.
Safety and ergonomic requirements
In the second step, the electric rail carts were limited by the length of their power cords and air lines and couldn’t run the full length of the line. They had a stroke of 20’, while the line length was 100’. Also, the carts’ cords and lines trailed behind them, limiting the operators’ access to the frame, and creating a trip hazard.
Finally, manual adjustments were required to position the frame onto the 3-strand conveyor. This created a safety risk for operators.
The solution had to incorporate two things – lift and transport. It also had to have a very low profile so that operators could interact with the large, heavy frame safely while directing it from the J-hooks to the 3-strand conveyor.
Battery-powered AGVs were considered
Battery-powered AGVs were considered but ruled out because the factory AGVs needed to operate 24/7 without leaving the line or stopping to recharge. Also, batteries didn’t offer sufficient power to simultaneously move the vehicle and power the lift. A heavy-duty lift with extra capacity for shifting side loads was critical to provide frame access and positioning.
Battery-free AGVs with wireless guidance were considered, but since there is no variance to a straight line path, this solution had more automation than necessary. A RedViking design standard is to never over-automate a project.
In the end, Wingspan™ battery-free AGVs with rail guidance were chosen. The AGVs’ inductive power provides 24/7 lift and transport, and rails offer an affordable guidance option for their straight line path.
AGV solution protects trucks and operators
Here’s our customer’s process today:
- Truck frames are brought to the line on large J-hooks, as before
- Using wireless controls, operators safely position the frames onto the AGV lifts, protecting the hoses and lines from damage
- AGVs are advanced to transfer the frame onto a 3-strand conveyor
- AGVs can run the full 100’ length of the line without any trailing cords or hoses
- AGVs reverse direction and synchronously return to start position
Advance prove-out creates uneventful install
We do all the prove-out at RedViking, taking the installation risk away from our customers. This is a sharp contrast from most conveyance installations, where there’s no way to fully test the solution except on the customer’s plant floor. We prove out all of the mechanics and controls on our one-of-a-kind inductive power test track in Michigan.
One customer thanked us for a “boring” first day back after installation, and another told us that their line had never started up so perfectly. The operators are really appreciating being able to operate the AGVs and lifts independently because it saves time and protects the frame components. Hoses and lines are not being crushed, and the solution is operating through all shifts without interruption.