Advances in electronics, battery technologies, and motors themselves have spurred electrification in various industries. Off-highway applications lead.
Electrification in the design-engineering space implies the use of electric motors to replace technologies based on fossil fuels, fluid power, purely mechanical kinematics, or even manual (human-powered) systems.
Fields leading in electrification are transportation distantly followed by manufacturing, construction, and energy infrastructure. Usually the goals are higher efficiency, precision, controllability, and sustainability. For the latter, electrification can leverage renewables already tied into electric-power utilities.
In transportation, vehicles eschewing internal-combustion engines for electric motors rely on specialized drivetrain components, battery systems, power electronics, and thermal management. No wonder transportation now accounts for the vast majority of electricity consumption increases … as the last decade saw U.S. automakers alone committing nearly $500B to transportation electrification — especially for electric vehicles (EVs) in the form of passenger vehicles, transit buses, and heavy-duty trucks.
Subsystems with any kind of motion generally follow suit. To illustrate, ballscrew actuators are used instead of hydraulic systems in EVs and commercial transport subsystems … especially those for active suspensions, battery-swapping stations, and aerodynamics assemblies such as active spoilers and grille shutters.
Electric actuators also integrate into commercial-grade automated charging stations. These charge fleets of cars off a single charge cable without requiring any driver involvement.
EVs of course include autonomous ground vehicles and other robotics as well.
In contrast with EV and other transportation uses, electrification in discrete automation that’s not in the form of mobile robotics often takes the form of electric-motor-based systems replacing hydraulic and pneumatic actuation. Among other things, this kind of electrification lets engineers connect more sensors and advanced controls for digital communications than would otherwise be networked. In this way, electromechanical systems are the most adaptable to digital-transformation or DX initiatives.
Just compare networking electromechanical systems to networking pneumatics. Many pneumatic-system communications are via analog or IO-Link signals. Electromechanical systems on the other hand offer myriad options for integration into advanced industrial networks, control architectures, and Ethernet-based protocols.
Where linear motion supports electrification
For linear motion, electric actuators with ballscrews and roller screws especially offer unbeatable position control in automated systems such as press-fit stations, servo-controlled tables of various types, pick-and-place gantries, and precision metering. As covered in the second installment of this series, these are all systems in which other motion solutions have traditionally dominated.
Other new uses of motor-based systems
Though not the focus here, process automation related to drying, space heating, cooking, and food-processing functions as well as building automation are other areas seeing equivalent electrification migrations. Electrification in heating and cooling is taking the form of electric heat pumps and chillers to replace gas-based infrastructure. The highest yields are when these electrified designs tie into smart grids and energy-management systems. Where economically feasible, large-scale energy storage (battery banks) complement such infrastructure.
Rail, sea, and air travel are three more areas of electrification. Rail in Europe, Japan, and China most heavily electrified. Maritime electrification includes hybrid-electric ferries, short-sea shipping vessels, and port electrification efforts to reduce emissions from docked ships.
Electrification in aviation is just emerging, but hybrid-electric propulsion and short-range electric aircraft prototypes have been developed. Startups Eviation and ZeroAvia are developing full-electric aircraft for short-haul flights possible even given today’s battery constraints.
Related article: Electrification from A to Z
Aerospace, defense, and renewable energy are yet other industries employing more electric systems. More specifically, electrified solutions have displaced others in satellite-antenna positioning and turret-aiming systems. The Mars rover uses servomotor-driven systems for high force density — a key requirement in aerospace applications needing to minimize payload. It’s the same trend in solar tracking and wind-turbine blade pitch controls. Electric-motor-based solutions have replaced certain hydraulics to minimize maintenance … especially when equipment is subject to extreme temperatures.
Electric systems also enable grid-based controls and remote access.
Off-highway applications
Electromechanical designs for mobile equipment trace design roots to decades-old work-vehicle designs needing auxiliary systems. But electrified vehicles today are in stark contrast with the electric vehicles of yore employing two-speed motor drives. Also new is that designing and specifying electromechanical systems for mobile machinery has become increasingly feasible.
No wonder in the construction industry, electrification of heavy equipment such as excavators, loaders, and concrete mixers is a huge trend. In fact, electric construction equipment is an estimated $14.5B market and projected to double over the next eight years.
On the leading edge of applications, electrification is also spurring the development of robotics for bricklaying, wall assembly, and roadwork. The other off-highway industry — that of agriculture — is also seeing mass electrification on tractors, harvesters, and farming drones … and that’s to say nothing of applications such as vertical farming that only came into existence recently and never without electric motors so essential to their various systems.
Adoption is still somewhat slow, but John Deere and Monarch Tractor along with dozens of smaller companies are continually developing fully electric and autonomous agricultural machinery.
Electrification is increasingly common on sprayer-boom controls, planter-row adjusters, and throttle as well as brake-by-wire systems. Electric linear actuators specifically are enabling powered seat, hood, and cab-step adjustments that would’ve been manual or supported by gas springs even a decade ago.
Electric cannot fully substitute pneumatic applications where higher velocity is required, but advancements in motor and screw technology mean electric actuators closing in on the speeds of pneumatics.
Comparable efficiencies make a strong case for migration. Off-highway applications are primed for electrification because internal-combustion engines get 30 to 40% efficiency whereas the most inefficient electric powertrains get 80% at least.
John Deere’s release of its self-driving tractor showcases the natural and predictable outcome of all this electrification. Such tractors tend fields by following GPS-mapped planting and harvesting paths. Electric-motor-based implements complemented by sensing and vision execute tasks while collecting data to inform future farming decisions.
To be clear, there are still only 20 of these particular autonomous tractors operating in the U.S. as of this writing. Perhaps that’s no wonder, because most farmers cite maintenance of farm equipment (and not its operation) to be a challenge.
Serviceability — a key electric-system benefit
Electromechanical solutions are a highly suitable fit here and actually anywhere that reliability is a top concern. That’s especially true when long operating lifecycles are an additional requirement.
If total reliability can’t be guaranteed, easy swapping with replacements is next-best … and this is another benefit that electric-motor-based solutions offer.
Especially with motor-powered subassemblies and electric actuators, in-field swapping can entail a quick mount and cable connection … far faster than swapping a hydraulic system needing maintenance-specialist attention and incurring costly downtime.
Again, uptime is often more important than cost-effective machine builds for off-highway settings. Plus, larger equipment is generally low volume (in some cases millions of dollars per vehicle) so priority is being able to reliably operate over a typical eight-hour shift. That’s why engineers often specify standard electric motors and complementary drives when electrifying such applications. Most all vehicles are built around twin frame rails … and in off-highway arrangements, usually designed originally for diesel. So unlike passenger EVs produced en masse with electric motors customized to interface some proprietary gear drivetrain, new electromechanical subsystems in off-highway industries are still needing to be modular and standard.
Two other benefits: Productivity and power
Off-highway applications are also a great example of where electromechanical systems tend to boost productivity. Speed, position, and acceleration can be precisely controlled over full motion ranges even with standard control electronics. On off-highway equipment, cabling for communications between these controls and the motors and actuators they command are usually via industry-standard Ethernet, bus, or I/O setups. So, there’s readily available access to data for various monitoring and condition-based maintenance functions.
What’s another reason off-highway applications are primed for electrification? These vehicles include lots of axes that deliver relatively slow yet high-torque (or force) motion.
Filed Under: Linear Motion Tips
