The implementation of electrified systems and components is nothing new for commercial fleets. However, the industry seems to be at a tipping point. Regulations and mandates are affecting OEM production and their utilization of electrification. Technology is making specified options available for today’s vehicles. Electric vehicles (EVs) are at a limit in terms of the operational demands of many fleets regarding range and the supporting infrastructure, yet the technology for autonomous EVs seems to be closer on the horizon than anticipated.
This leaves fleets with a difficult decision: how to adapt to the electrification trend.
Industry manufacturers are offering many different electrified systems and components now to be utilized with today’s fleets. Electronic stability control, e-Axles, electrified transmissions, power distribution units (PDUs), electrified auxiliary power units (APUs), motor and inverter systems, and more are being specified on commercial vehicles driven today in order to enter the electrification trend and, most importantly, start reaping the rewards of doing so. Cuts in maintenance costs, data production, and performance advantages are major reasons fleets are adapting to the evolving technology. This article will examine some electrified components that can be implemented into a fleet today, their benefits and challenges, and the ways in which a fleet’s electrification will affect operations.
Electronic stability control
The Federal Motor Vehicle Safety Standards (FMVSS) mandated electronic stability control systems on heavy duty vehicles via FMVSS Title 49, part 571, Subpart B, Standard No. 136. By August of this year, all Class 7 and 8 vehicles manufactured in the U.S. must comply with this standard.
Bendix Commercial Vehicle Systems, a supplier of active safety technologies, energy management solutions, air brake charging, and control systems and components, has developed the Bendix Electronic Stability Program (ESP) system, anti-lock braking (ABS), and traction control technology, in order to add support for drivers and fleets to mitigate rollovers and loss of control situations. The Bendix ESP system is built on top of an advanced braking system in order to assist drivers with ABS through its brake controller.
“The brake controller is the brains of the operation," says TJ Thomas, director of marketing and customer solutions – controls, Bendix Commercial Vehicle Systems. “It takes into account all sensor readings and makes the decisions to apply brakes to which individual wheel ends.”
The ESP is built on the brake system. In addition to the brake system’s sensors, modulators, and wheel speed sensors, two components essential to the ESP’s functionality are the wheel steering sensor and the yaw lateral sensors. The wheel steering sensor measures wheel angle and determines the driver’s intended steering direction. It possesses an ability to assist driver action with steering in order to maintain stability. The yaw lateral sensors measure lateral, side-to-side motion. In tandem, these two sensor systems translate driver intent and vehicle performance. If the sensor measurements are out of range for set parameters, the system will automatically take action to mitigate instability.
Fred Andersky, director of the Bendix Demo Team, explains the two-fold benefits of the Bendix ESP as they pertain to the driver.
“Out in the field, [the system] helps a driver mitigate rollover and loss of control situations," he says. “Secondly, the system helps the driver learn. When the driver gets an intervention, whether the throttle is cut or brakes are applied, they get the idea that, ‘Hey, maybe I took that turn too fast,’ or, ‘I need to slow down.’ It provides mitigation and training.”
To maintain the ESP, it is crucial to continue proper maintenance procedures for the ABS system. The ABS, and therefore the ESP, can only be as effective as how well the wheel ends are maintained. Proper care should be taken to keep wheel ends and the braking system in good shape. For instance, brake pad changes, rotor changes, ensuring clean air is in the system through filter maintenance, proper tire inflation, and measuring tread depths help the entire system perform.
Wheel speed sensors, being a metallic sensor placed near the tire, are subject to rain, salt, snow, sand, and dirt exposure. They can shift and must be properly adjusted. Wiring is also susceptible to elemental exposure and should be inspected through regular PMs.
“Generally speaking, there is not much routine maintenance [for the ESP], other than the [maintenance of the] brake system that is specifically required,” says Kevin Romanchok, director of eMobility and new business development at Bendix. For diagnosing ESP system issues, Bendix offers ACom diagnostic software. “It is important that the technicians understand how to use that to see active or inactive codes, perform component testing, and address the problems,” says Romanchok.
Andersky also mentions it is important to recalibrate the sensors, such as the steer angle sensor, when certain maintenance procedures are performed on the vehicle, including front-end alignments. These recalibrations can be completed through Bendix’s ACom diagnostic software.
A PC-based diagnostic system, ACom connects to the vehicle truck-side, connecting to the ECUs of subsystems, allowing technicians to examine error codes and recommended procedures for repair. A technical support team is available to answer questions and assist with diagnostic procedures. Bendix also conducts system demonstrations, which both drivers and technicians are welcome to attend in order to gain an understanding of what the system does and why it is being implemented into a vehicle. Bendix’s service engineering staff also offers on-site training for fleets.
Bendix offers a myriad of information and training specifically focused on the ESP. Avenues include documentation, training, diagnostics, support teams, and demonstrations. Thomas suggests the first line of learning should be through the service data sheets. The service data sheets are published on Bendix.com and they explain proper system operation, system components, and how to troubleshoot the system. The detailed sheets cover all aspects of the system and should be the first resource technicians reference in order to familiarize themselves with system operations.
Aside from the service data sheets, there are also operational manuals and technical bulletins. Another source of information is the educational services of brake-school.com and the on-site Air Brake Training and Advanced Technology Training courses. These courses are held across the U.S. at Bendix office locations. Technicians attend these events, which are several days long, to understand the troubleshooting and diagnostic procedures of the entire brake system. Brake-school.com is a source of targeted information for all Bendix systems, from brakes to wheel ends, ABS, and ESP. Technicians can register for free to utilize the site, fleets can follow technician training progress, and users can complete quizzes to test their knowledge. The site contains videos focused on specific aspects of maintenance intended for technicians to obtain the desired information and return to the vehicle quickly, decreasing downtime.
Electronic axles and transmissions
A major step on the electrification path is the implementation of e-Axles or electrified transmissions into a fleet.
Drivetrain and propulsion systems provider Dana has acquired or partnered with numerous companies such as TM4, SME Group, Ashwoods, and Hyliion in order to address the industry movement toward electrification. This has allowed Dana to integrate high and low voltage motor mechanics into their vehicle systems and to develop their line of e-Axles for the commercial market.
“The e-Axle is a game changer in the overall propulsion system,” says Harry Trost, senior manager of commercial vehicle product planning at Dana. “The e-Axle puts the entire powertrain system into one compact package that fits in place with the current axle on there today.”
The e-Axle enables many performance benefits for the EV, such as the elimination of diesel, a lighter weight, improvement in powertrain efficiency, and opening space in the vehicle’s chassis for batteries. The space created through an e-Axle allows for the packaging of the right amount of batteries to reach the desired range for the vehicle. The regenerative braking offered through an e-Axle also helps to combat the range anxiety that fleets may have with EVs, as it is able to recapture energy and return it to the battery.
Another aspect of the e-Axle is its tuning ability. From an engineering perspective, the e-Axle can be tuned in how the torque ramps up in the e-Motor, allowing for high, instant torque capability. Parameters can be set to customer preferences, says Trost. With some limitations, these parameters can even be modified with over-the-air updates to change the software in near real-time to alter behavioral characteristics of the vehicle. An example would be with how aggressively or mildly the regenerative braking system is responding. Dana offers recommendations on how the vehicle should be tuned, accounting for multiple factors of operation and vehicle components.
“Talking with customers on this journey of electrification, they are seeing a two-thirds maintenance [cost] reduction with an electrified powertrain,” Trost says. “This offers significant savings, from a maintenance standpoint, and [fleets] have that uptime they are looking for.”
As e-Propulsion systems allow for regenerative braking, installation of such systems can lead to a benefit in decreased intervals of braking system maintenance and extended brake life, as well as a reduction in time, cost, and effort associated with servicing the brakes.
Dana provides two avenues of support regarding service parts for their e-Axles, as customers can go through OEM dealers or utilize danaaftermarket.com to obtain the service parts needed.
Servicing the e-Axle itself has not caused many changes to the PM procedure for technicians. The most notable difference would be that technicians are now dealing with high-voltage cabling and batteries. PMs associated with high-voltage cabling require safety precautions to be taken by service professionals. Wearing personal protective equipment, properly disconnecting the battery, and lock-out/tag-out procedures all must be integrated into a fleet’s PMs.
Dana’s Driveline Forensics training videos and the Aftermarket Training Academy provide training and educational information for technicians that are servicing the e-Axles. These resources develop alongside product development, ensuring technicians understand how to maintain the vehicle’s components.
Allison Transmission, manufacturer of commercial-duty automatic transmissions and electric hybrid propulsion systems, offers the ABE Series e-Axle for the bus market and the AXE Series e-Axle for medium and heavy duty trucks. The ABE Series e-Axles is a compact and fully integrated bolt-in system that replaces the entire traditional powertrain within the existing frame. Its installation allows space for battery packs and other electrical components to be installed. The AXE Series e-Axle is a fully integrated powertrain system that fits inside a standard frame along the axle of commercial trucks. This system includes power electronics for a complete powertrain solution.
The ABE and AXE Series e-Axles provide good torque without the noise associated with a combustion engine. Not only is there a noise reduction, but there is an emissions reduction as well.
“Electric vehicles can also reduce the emissions that contribute to climate change, thus decreasing environmental damage,” says Michael Foster, chief technology officer, Allison Transmission.
Adoption of e-Axles in EVs indirectly affects other vehicle systems, as there is no longer an engine, transmission, fuel system, or aftertreatment. Hybridization with combustion engines also elicits improvements on vehicle systems, particularly extending part life and extending service intervals, ultimately resulting in a reduction of maintenance costs. Vehicle accessories will need to be adapted in order to operate through electricity. Foster also speaks to the alteration of vehicle system sensors, as different sensors will be required while traditional sensors are eliminated. “Sensors are designed to continually monitor vehicle operation and capture data when vehicles’ components fail to operate correctly. With new electrified components, traditional sensors will be unable to connect,” says Foster.
The ABE and AXE Series e-Axles offer significant maintenance benefits, as there are no fluid changes and the systems contain considerably fewer parts for wear and tear. “Additionally, with the advancement of telematics, there will be more diagnostics ahead of time to ensure vehicles are maintained at the appropriate intervals and repairs made before any major issues arise,” says Foster.
The main challenge facing the adoption of electrified systems is the training that will be required of technicians servicing such systems. Technicians will need to have a skill set suited to service these systems properly and safely. Allison Transmissions offers a maintenance and service network that Foster says the company plans to leverage alongside the electrification movement.
Eaton, a power management company and manufacturer of powertrain systems and components, established an eMobility business unit, which contains three distinct product categories: power electronics, power distribution and protection, and power systems. As part of their power systems, Eaton has developed electrified transmissions for commercial vehicles. Julie Marshaus, manager of new product introductions – systems at Eaton, explains that Eaton has been in the electrification market for some time, especially through their hybrid vehicle products. eMobility was not created from scratch, but rather drew from the company’s experience and knowledge gained through the hybrid component developments they had enacted and its unit focused on full electrification.
Eaton’s electrified transmissions deliver a motor torque profile significantly different than that of a diesel engine. In order to be able to meet performance demands, diesel engines may need 12-18 gears; vehicles with Eaton’s electrified transmissions need only 3-4, or at most 5-6 gears, Marshaus says. The transmission has been simplified with Eaton’s electrification process: a lower oil quantity, no high-low range box, fewer internal systems, no clutch, no clutch actuator, no range valves.
Adding an electrified transmission to an EV, rather than having a direct drive electric motor, “delivers greater start-ability, better grade-ability, and energy efficiency,” Marshaus says. Another major benefit: environmental footprint. “We hope that the EVs will help with greenhouse gas emissions and make the world a cleaner, better place,” Marshaus says.
With the removal of many systems and components in a traditional transmission, electrified transmission maintenance becomes less complex. There are still gears to maintain and oil change intervals, but there are no real new PM procedures to implement. Drivers will have to adjust to the noise reduction while operating, and technicians will need to be aware of the protocols associated with high-voltage servicing.
Eaton publishes troubleshooting guides and maintenance documents on how to service electrified transmissions, which also come with a control module that is updated through Eaton’s service tool. The implementation of the transmission does not require additional sensors to be specified on a vehicle to accommodate for such a system, but changes in vehicle architecture may result in changes to existing monitoring sensors.
Power management
With the electrification of a vehicle changes in power management become necessary. In many cases, the management and distribution of the high- and low-voltage power must be reinvented to account for changes in the operation of the electrified components and systems. The ability to properly and precisely route the power to the various systems becomes explicitly crucial.
A challenge with EV inter-system operation is the differentiation in voltage required for system operation. Eaton offers a variety of power distribution units (PDUs).PDUs take high-voltage current and distribute the necessary voltage to accessory systems. PDUs also help the OEM and the fleet itself understand how the power is being used in the vehicle. It can even determine predictive maintenance with imminent system maintenance requirements or possible system failures.
“Some smart PDUs are capable of recording or broadcasting power consumption of accessories,” explains Eaton’s Marshaus. “[Smart PDUs] can track power draw and give an idea if a component is close to failure.”
Dana provides flexibility in electrification adoption through their motor and inverter systems. These systems convert DC power to AC power for the motor, allowing the drive to adjust the frequency and voltage being supplied to the motor. With different models for separate circumstances, these systems allow for a central direct drive approach or can be implemented with e-Axles and full EVs.
“[The central mount direct drive approach has] minimal impact to vehicle architecture,” says Dana's Trost. “It can be implemented quickly, it is in production today, validated, and can be sold with a warranty.”
This approach allows customers to maintain conventional drivetrain components, such as the driveshaft or axle. Implementation of EVs and e-Axles offers increases in efficiency and range, as well as more space for battery packaging.
Thermo King, manufacturer of transport temperature control systems, developed the TRIPAC Envidia APU to assist in a vehicle’s adoption of electrification through its ability to control the power and voltage necessary to operate select vehicle systems with battery power. The electric APU provides enough auxiliary power to run the vehicle’s HVAC system for up to 10 hours, according to Steve Hubbard, engineering leader, electrification center of excellence at Thermo King.
A unique aspect of the Envidia is its battery management system. “Using AGM batteries for an APU, the management system protects the entire battery bank if one battery were to go bad,” Hubbard says. “The system isolates a failed battery [so that a fleet] only needs to deal with the cost of one failed battery versus an entire bank.”
Electric APUs offer a zero-emission alternative to traditional APUs which utilize diesel fuel. The only anticipated maintenance with an electric APU would be battery replacement, normal with any battery replacement cycle. PM procedures should accommodate battery monitoring, and including the APU will add efficiency to the vehicle’s battery system altogether. There are no modifications necessary to the vehicle’s ECU if it already has the ability to monitor battery voltage.
With the Envidia, customers can have the user interface installed in the cab rest area. There are independent sensors to monitor the temperature and operation of the APU itself, as well as the cab. A simple user interface device contains a temperature sensor and controls to adjust cab temperature. It also includes a display for state of charge on the battery, shown through a set of LEDs. The interface is as small as a person’s hand and can be installed on the wall or console.
What next?
For now, there is flexibility in the pace and extent to which fleets adopt electrified systems.
Federal mandates such as the Clean Air Act, or state regulations such as California’s resource board (CARB) emissions standards, have been, are currently, and will continue to develop and further impact fleets' operations and makeup. The technology to ensure compliance with such regulations will become more prevalent, alongside the acquisition of more and more data on the environmental and logistical impacts such technologies offer.
With further federal and state regulation changes imminent, technologies available today and in the future are on the path of potentially drastic change. Fleets must evaluate their current and future operational requirements to decide for themselves if, how, and when they adopt electrification.
Can the fleet’s demands be met with full EVs? Will electrifying one vehicle pose a data and research opportunity to extrapolate viability for the electrification of the entire fleet? Does a fleet hold out on electrifying their vehicles today in hopes of full EVs capable of meeting their demands tomorrow? There is much to consider when looking at the electrification of fleet vehicles – and the ability to successfully execute such a drastic upheaval in the status quo of operations will make all the difference.
