Electrified Heavy Machinery: How can you avoid late error findings for manufacturing, assembly and maintenance processes?

As heavy machinery & equipment OEMs develop electric-powered versions of their conventional internal combustion engine (ICE) powered products, they will displace several existing systems with new zero-emission equivalents or variants optimized for a combustion-free future. Electrification introduces new packaging constraints that the heavy machinery industry has little to no experience with.

Product operation, manufacturing, and maintenance process planning will be impacted by the types of components included in the design. When considering new or novel products, development teams risk painting themselves into a corner if decisions regarding product topology and human-centric processes go too long without consideration. It would be a shame if an innovative electric drivetrain was delayed due to oversight in lack of accessibility, limits to the range of motion, or engineered length of a power cable to its corresponding sockets!

In my previous post, I discussed the impact of electrification from a systems perspective. In this post, I’d like to expand on Product Integration challenges addressable through the use of Virtual Reality to conduct Human-Centric Process Validation & Product Integration reviews. 

Finding the right placement, or packaging, for new components is an exercise in creativity, designing “inside the box”. Space previously claimed by the combustion engine and transmission might be used for batteries but could also house other systems. Packaging envelopes, or volumes, previously allocated for energy transfer from the engine through driveshafts, u-joints, and differentials could be overtaken by electric motors, gearboxes, and power cables. Design standards and criteria for product packaging for off-highway heavy machines, automobiles, and aircraft are the results of cumulative experience in engineering, manufacturing, assembling, and maintaining real products; the industry has only recently started to accumulate EV experience and reliable design standards for such novel products are still to come.

We may use digital tools like simulation and analysis software to evaluate design, but defining “pass/fail” criteria requires practical experience in real situations of assembly, operation, and maintenance of real – most often ICE – products in the real world. This means that often we can only see what we specifically set out to measure or predict; the opportunity to “discover” new risks or potential issues requires prior knowledge to define a deterministic simulation to measure an effect. Little chance remains to unearth a new issue until people work with real objects and experience the procedures first-hand – but that is too late!

Widely available Computer-Aided Design (CAD) and Digital Mock-up (DMU) solutions can identify and measure the clearance between adjacent systems and sub-assemblies in a design, but designers need to remember that components are not “born” in their final part positions but need to be placed thereby, in most cases, human operators. Therefore, identifying feasible installation and removal paths is more than just making sure that clearance exists, but that the available clearance is practical for a human operator to use during assembly or maintenance.

Because of the “deterministic” nature of most simulations and analyses, we only find specifically what we were looking for; if we do not suspect a problem in accessing or reaching something, we would not define CAE or FEA simulation to predict it. This leaves risks that when the line starts and products start shipping, latent issues with the product and/or process emerge, very late. By that time, fixing or mitigating any issues is prohibitively expensive, reduces quality, or delays on-time delivery.

During operation of new electric versions of products, cables, hoses, and wires within the system may need “wiggle room” that suits the full range of motion when connecting articulated or moving componentry, static packaging or space claim reviews may not be sufficient to identify risks to the product and/or operators during typical use. Over- or under-constrained cables might not be able to withstand cyclical movements or vibrational damage. Positions of clips, guides, and channels that protect those wires or cables during operation should prevent abrasion, wear, pinching, or pulling free.

Additionally, those same connections will need to accommodate the assembly process and service or maintenance processes.

Certainly, there are many deterministic simulation-analyses that could be used to predict failure modes, but each simulation could require a discrete input set of boundary conditions and assumed motion path making each evaluation of a cables design take hours of preparation, computation, and interpretation. Instead, with Human-Centric Process Validation & Product Integration solution IC.IDO, users can simulate the interaction of the hose/cable with the movement of the solid bodies of the device and possibly with human operators to predict behavior in real-time. Letting users experience immediate feedback on the behaviors of those cables/hoses without waiting for weeks to construct physical mock-ups or hours to compute deterministic CAE or FEA results. 

A significant opportunity for gains in electric product development is the design and validation of wire harnesses within proposed electric variants of heavy machines and off-highway vehicles. The integrity of the wire routing and planning is of yet-to-be-fully realized importance. Anyone who has had their ICE car begin to exhibit electrical problems can attest to the tricky nature of electrical issues in complex vehicle systems. 

When drawing a cable in CAD it is most often drawn as a “pipe” or cylinder. Few tools in use account for the fact that a cylinder drawn to take a complex shape will have a different overall length than if we took real flexible wire and physically routed it along the same path. Flexible bodies like wires, hoses, and cables making a serpentine route will not have the same length requirement as the computed centerline of the “pipe” or the outer sheathing—the neutral line for flexible hoses or cables will not be at the centerline. In practice, this can result in an unpredictable number of cables or hoses that are too short to reach their intended positions and others that are too long to avoid pinching or binding during operation, installation, or removal.  

In extreme cases, this can result in cable and wire harnesses for variants within the same product line that have unique SKU numbers for seemingly identical wire harnesses or hoses. It could require the design and construction of unique tooling fixtures for the subassembly and staging of similar harnesses due to subtle variances in the harness designs and routing that evolve at different times in the product life, adding unplanned complexity and risk of quality issues downstream. The ability to run trials with true-to-life deformable wire harnesses or hoses, early enough in product development to anticipate and plan for tooling use and interoperability, will reduce risk while accelerating product development timelines.

If you are interested in learning more about achieving early confidence in product performance, realizing efficient enterprise-wide collaboration, and ensuring sustainable first-time-right physical prototyping, watch our webinar series on-demand on Human Centric Process Validation & Immersive Product Integration.