Augmented Reality Lowers Errors in Automotive Manufacturing

According to mathematical models, manufacturing processes can become highly data driven, nimble and responsive. People and equipment are deployed to optimize resources whenever shifts in demand, supply of components or materials, or currency exchanges reach thresholds. In practice, application of such models raises significant challenges.

In complex assembly lines such as for cars, companies seek to strike a balance between customization (made to order vehicles) and mass production. It’s not uncommon for a single assembly line to finish parts for different car models and colors. Dynamic, configurable equipment and workflows are easier to program and manage than in Henry Ford’s day, but they also introduce complexity into operations. Complexity introduces errors. And errors cause production delays, also known as downtime.

Improvements in operator training can reduce downtime but if employees must memorize complex steps that change frequently, it does not guarantee the best resource use. Delivering precise work instructions to the assembly line worker at the time of task performance and in the field of view of the user has enormous potential to bring the real world closer to the textbook models.

Projection Augmented Reality

Projection Augmented Reality is an alternative to tablets or smart glasses in some environments. The approach is well suited when the workplace is stationary (or on a moving assembly line) and the work tools or items on which a task is performed can be brought to the AR-enabled workstation.

One company providing projection AR capabilities is OPS Solutions. OPS Solutions works with automobile manufacturers such as Fiat Chrysler Automobiles to increase workplace efficiency and productivity. This article describes a study conducted with OPS’ flagship product Light Guide Systems (LGS), a projection AR solution that has been implemented within Chrysler’s manufacturing operations.

Manufacturing Study

LGS projects instructions (visual and audio) for guidance, pacing and direction on work surfaces, and provides feedback for improving industrial processes such as capturing cycle times for each step within manual processes including assembly, part knitting and training. In trials conducted with Chrysler in 2014, use of standard paper work instructions for complex tasks were compared with using LGS for the same tasks when training new operators. Ten operators were tasked with assembling gears and chains, a process totaling 10 steps for each operator. For each step, they had to select the correct gear corresponding to a location and diameter within a standard cycle time, and install the corresponding chains correctly. Lastly, they had to verify that the installation was done correctly.

Each operator had to do two different versions of each task, one using paper-based work instructions, and the other with LGS. Five operators started with paper and then switched to LGS, and the other five with LGS and then to paper.

The results of the study are conclusive, and the table below shows the efficiency of LGS in comparison to standard paper work instructions.

The 80% reduction in errors shows a marked improvement in quality. Reducing errors at one stage of an assembly line has great impact on costs, since faulty articles must be withdrawn further down the line and corrected in order to proceed with later stages of assembly.

The reduction in cycle times and increased throughput reflect efficiency and speed, as articles completed faster increase overall manufacturing productivity.

A similar study was done for logistics tasks, or kitting and sequencing of parts before reaching the assembly line. Associates had to select the correct subparts and put them in the appropriate bins on a cart, before wheeling the cart to the next stage of production. They used LGS to project selecting the correct quantities of parts and guiding the associates to place the parts in the correct bins based on a highly variable sequence that changes constantly in production.

The study similarly compared the efficiency of using projection Augmented Reality with that of paper work instructions. As shown in the table below, using projection AR greatly increased the associate’s efficiency and reduced errors.

In both the assembly and logistics studies, a further advantage of instructions displayed directly in the field of view is that the normal attention switching to refer to other sources of information such as paper or computer-based work instructions is eliminated, thereby reducing cognitive load and speeding up task execution.

A Leap in Productivity

Chrysler’s experience with projection Augmented Reality supplied by OPS reveals the potential this technology offers to boost employee productivity through:

• Increased quality and standardization of processes
• Training efficiency by enabling operators to self-train on the job
• Greater accountability through confirmations of successfully completed steps
• Feedback on completed tasks and cycle times

One byproduct of designing, installing and using projection AR is that the plant floor workflows and stations are reviewed and improved. Reconfiguring stations can increase efficiency with respect to material staging and ergonomics.