Welcome to Zupt Autonomous Products and Technologies (ZAPT) second blog series: Stories From Our Engineers.
As a technology company, our engineers have combined their knowledge from mechanical, navigation, localization, perception, and electrical engineering fields to build our first fully autonomous product, a robotic commercial lawnmower known as Nomad. During this series, several of our lead engineers will share their take on how they played a role in designing Nomad, what makes it unique to them, and the future they see. The first engineer we would like you to meet is Wes, the Senior Mechanical Engineer responsible for Nomad's mechanical design and build.
Pictured: Josh (Left) and Wes (Right)
What He Brings
Wes's background is in small combustion engines and optimizing their performance on various platforms, like Nomad. Along with his background, his interests lie in engines, computers, and how to autonomously control things through software - making him the perfectly suited engineer for the job. As he says, "I didn't know it, but my experience set me up perfectly." In fact, his family says they always knew he would become an engineer. They tell stories from his childhood, that when there would be silence, they would find him in another room taking a whole tv apart to quote-on-quote "fix it." Ironically, once, he even took apart an entire lawnmower just to put it back together. This deep desire to get his hands dirty to build things and his passion for knowing how things work are what he continues to bring to creating Nomad.
What He Does
When asked where he begins to design something that has never been created before, he said, "I start the same place everyone starts; at the beginning." He started by asking himself, "what is the simplest part you need?" a frame or a skeleton. He knew the lawnmower needed to be as big as 60 inches and as skinny as 30 inches to mow to our desired functionality. After that, it was figuring out how to fit what we needed inside this envelope for Nomad to run. Ultimately, the design emerged over time made on our design requirements. For example, because we wanted size transformation capability and four-wheel steering, there were certain structural elements we had to have. "The design got turned into the shape because we needed the features," says Wes. It was these somewhat unusual criteria that, over time, created the design.
Wes has four primary responsibilities: ensuring the functionality of Nomad's powertrain and drivetrain systems, designing the electronics enclosure that houses "the brain," enabling Nomad to transform from fat to skinny, and creating the grass cutting deck.
Ensuring the functionality of Nomad's powertrain and drivetrain systems by:
Selecting the correct engine to use
Choosing the correct hydraulic pump needed to run all the systems (drive wheels, steering, deck blade motor)
Choosing the right size wheel drive motors, steering motors, and deck blade motor
Have all other hydraulic components needed to build Nomad (hoses, tanks, filters, valves, manifolds)
Size and find the fuel tank
Make all mounts for the above elements and ensure that they are strong enough to withstand mowing over time
Designing the electronics enclosure that houses "the brain" by:
Designing all base plates, covers, heat sinks, camera mounts, antenna mounts, antenna shielding
Designing a dampening system to contain the electronics
Weatherproofing/dust proofing this enclosure
Enabling Nomad to transform from fat to skinny by:
Designing arms that are capable of independent steering and drive
Designing a frame that is small enough to fit inside the size envelope of the 30 "by 60" deck and allows the arms to attach securely
Designing a spline locking system that allows the arm to unlock and transform to a new mode
Creating the grass cutting deck by:
Designing the deck to adhere to the ANSI/OPEI standards for strength and durability
Designing the hydraulic drive motor system for the blades to be driven hydraulically.
Designing a deck raising and lowering mechanism enabling the deck to move from 1.5" to 5.5" cut height.
What He Likes
To Wes, creating an autonomous lawnmower that is safe, reliable, and delivers high productivity as an all-terrain vehicle is the most valuable feature. As discussed above, the design transformed over time from the criteria and features we wanted Nomad to perform. Nomad has four-wheel steering that can take on hills, slopes, and even mud. Ultimately, "it's like a four-wheel drive truck."
Also, the ability for Nomad to transform from 60 inches to 30 inches makes itself uniquely valuable, and Wes is "interested to see where the market is for that." Nomad's ability to transform sizes allows it to go through gates, between trees, and fit through other narrower areas to reach more land to mow more grass.
What He See's
Overall, Wes is excited to bring the lawnmower industry into the future – and this does mean eventually moving from our current gas-powered unit to an all-electric, battery-powered unit. He is "excited to be a part of that, being in this era," to see how the market responds to a fully autonomous lawnmower." Specifically, his first goal is to see Nomad function in the field as a highly productive grass-cutting machine, fulfilling the original design criteria of transforming and navigating through challenging spaces. His second goal is to see the project deliver revenue by meeting and exceeding customers' expectations through ease of use and mowing capability. Finally, his last goal is that Nomad accumulates countless orders that he has to figure out how to complete and deliver.
Next time, our Stories From Our Engineers blog will feature Lily, one of our Navigation Engineers responsible for object detection and LiDAR map matching. Lily develops localization and perception algorithms for Nomad.