This article also appears in
Subscribe now »

Commercial vehicle manufacturers are using more blade-and-receptacle connectors, such as this MX123 sealed connection system from Molex. It is designed for high-vibration, under-the-hood powertrain applications while still maintaining a small packaging size.

Tracking the trends in commercial vehicle communications

Seasoned operators of commercial vehicles will say they can sense how their vehicles are performing based on the sounds and vibrations the vehicles produce. Today, the latest commercial vehicles can do that on their own via sophisticated communications systems that monitor performance, position the vehicle, schedule needed maintenance, communicate with accessory equipment, and even help drive the vehicle, among other functions.

These communications systems require myriad electronic components. In this article, Molex examines some of the communications component trends it anticipates for commercial vehicles in 2016, including challenges to implementing 24/7 communications, interaction with other communications systems, and changes in standards.

There are a host of vehicles that require complex interconnect systems, such as agricultural vehicles that precisely monitor sprayer output; commercial busses with Wi-Fi networks, plug-and-play entertainment systems for passengers, and multiple security and driver-assist camera systems; and emergency vehicles that process critical data from patient monitoring equipment. For purposes here, Molex focuses on two critical heavy-duty applications: agricultural and construction/mining vehicles.

Commercial vehicle communications scenarios

Agriculture vehicles with 24/7 communications systems offer important competitive advantages. For example, communications modules in tractors and implements ensure that croplands are precisely planted and harvested with greater efficiency. These modules can regulate distribution of fertilizer and seed, which improves cultivation and crop yields.

Also, if there is a problem with a tractor, combine, or implement, the dealer or the operator can be automatically alerted via wireless communication, depending on the severity of the issue. Since machine uptime is vital, this application can improve farming productivity.

Communications systems are obviously a key part of autonomous agricultural vehicles, which free farmers to perform other tasks. Some of these systems coordinate multiple autonomous vehicles, such as when a tractor grain hauler receives grain from a combine that is harvesting a field of crops.

For construction and mining vehicles, 24/7 communications systems have an added importance. Unlike, agricultural vehicles, which are used heavily for certain periods and then housed, many construction and mining vehicles operate nearly 24/7 for indefinite periods, making maintenance diagnostics and communications systems that much more critical.

Also, multiple cameras and sensors are needed on both agricultural and construction and mining vehicles to ensure safe operation in often dangerous work environments. These communications systems typically include devices such as video cameras and displays, along with complex sensor and control systems that produce large volumes of high-speed data that assist operators with crucial tasks.

Free-flowing data

With more data flowing through commercial vehicles than ever before, communications systems require high-speed connectors and cables that can transmit 5 to 10 Gbps of data to transfer images and video. While some of these connectors handle data only, the trend is to use hybrid connectors that can handle both data and power, some of which can be specified with two or four lines of signal and power.

One major challenge with hybrid connectors is the electromagnetic interference (EMI) generated when power is transmitted through the connectors. As a result, connectors and cables in these systems must be shielded to protect them from EMI and crosstalk. Common shielding methods include individual shielding via aluminum foil for each twisted pair; foil shielding, braided shield or braiding with foil across all of the pairs; and individual shielding via foil between the twisted pair sets combined with an outer foil or braided shielding.

While much of this technology is not new, its application to the commercial vehicle industry is more recent. Manufacturers are now adopting various high-speed protocols that have been used by other industries for years. The difference is that communications systems for heavy-duty vehicles must be ruggedized, particularly in terms of latching and sealing.

That means communications networks in commercial vehicles must provide all the benefits of high-speed networks found in automotive vehicles as well as greater protection from increased vibration, shock, and fluid ingress. Plus, they must accomplish this while being housed in more complex and denser packages. As a result, high-speed interconnect systems have been modified to meet the challenges emerging from the commercial vehicle industry

Networking evolution

Typical USB interconnect systems are based on passive, unlatched, plug-in connectors, but automotive USB applications must be latched. As a result, unsealed USB connector systems for automotive applications include shrouds and latches that meet USCAR standards.

Compared to automotive applications, however, heavy-duty, off-highway applications typically require sealed systems with additional protection against increased vibration, shock, and fluid ingress. For that reason, interconnect systems for commercial vehicles require fully protected perimeter seals and wire seals rated to IP67 and IP69K for use in off-highway environments.

Sometimes, an even more ruggedized product is required for use on vehicle exteriors. These metalized interconnect systems, which are sometimes available in high-speed CAT 6 versions, are typically sealed, threaded, and have metalized shells and push/pull locks. Some versions can even withstand a 300-lb pull force and are designed to withstand the driver of a vehicle standing on the cable when entering or exiting the cab.

Likewise, sealing technology that has been tested and approved in other industries can be used in electronic components for commercial vehicles. That includes different levels of sealing proficiency, from protection against dust or light sprays to protection from a stream of water from a hose to being able to be fully immersed in water.

When protecting components from vibration in commercial vehicles, it helps to have multiple contact points within the connector system. Commercial vehicle manufacturers have traditionally used vibration-resistant pin and socket connectors because they provide multiple points of contact for the socket around a cylindrical pin. Their counterparts in the automotive industry, however, have mostly transitioned to less-expensive blade and receptacle connectors, which also offer multiple contacts.

Commercial vehicle manufacturers are now embracing this trend. Traditionally, blade-and-receptacle connectors were not appropriate for high-vibration environments, but newer designs have been refined to the point where, based on the contact’s geometry, they can withstand up to 20 g. For example, the MX123 sealed connection system from Molex is basically a blade-and-receptacle system. It is designed for high-vibration, under-the-hood powertrain applications while still maintaining a small packaging size.

Changing sensors and standards

Another key component trend in commercial vehicles is the growing use of sensors. The challenge will be determining how information is collected from those sensors and how it is provided to a screen or interface in a manner that doesn’t overwhelm the operator.

Both the types of sensors and their sheer numbers are increasing, including sensors for lighting, air/tire pressure, current, and positioning, along with gas, brake, and hydraulic fluid levels. Sensors specific to agricultural vehicles include hopper level, application-rate, and high-rate seed sensors.

Also, the manner in which sensors and connectors are specified in communication systems is evolving. Agricultural vehicle manufacturers tend to follow ISO Bus communications standards such as ISO 11783 and construction and mining vehicle manufacturers tend to follow SAE standards. In addition, commercial vehicle manufacturers also use their internal proprietary specifications for higher-level communications, which make vehicles and equipment made by the same manufacturer interoperable.

However, this also means they may not effectively communicate with equipment made by other manufacturers. While these proprietary specifications and requirements are a problem for customers using vehicles from different manufacturers, it allows individual manufacturers to differentiate their products and develop a competitive edge for their vehicles.

For example, many manufacturers of connectors for commercial vehicles work with the SAE J2030 specification, which encompasses connectors between two cables or between a cable and an electrical component and focuses on the connectors external to the electrical component. The specification describes the minimum criteria needed to establish that a connector will work in a ruggedized application.

When developing a connector for commercial vehicles, Molex will typically test it to J2030 because that provides the company with a “calling card” when it wants to qualify the part with a customer, such as Caterpillar or John Deere. Customers may accept a part based on it passing J2030, then test it further to determine if it meets their own internal specifications. Some manufacturers share those internal specifications with suppliers and some do not.

Managing the ‘pizza box’

One thing to keep in mind when designing a high-speed and high-power interconnect system for a commercial vehicle is that it is part of an overall vehicle architecture involving high-speed communications and high-power electrification systems. For example, in addition to standard body/chassis, safety, powertrain, and infotainment connectors, an emerging trend is toward electric drives and accessory connector systems for high-voltage power applications.

A large number of wires and connections are routed to control modules that can be the size of a pizza box. Just trying to get the mixture of straight and right-angle entry wires routed through the vehicle is an ever-increasing challenge.

As a result, smaller, lighter, and more flexible connectors that allow easier cable exits are required. For example, a 1.5-mm terminal may need to be downsized to 1.2-mm, and 18- or 20-gauge wire replaced with 22-gauge wire. Likewise, smaller insulation diameters and lighter weight aluminum wire may need to be used instead of copper wire.

Another option might be to move to single-mode glass or plastic fiber optic cable. One fiber optic line can replace multiple copper wires. Also, some manufacturers are using flat cabling because it can be mounted flat to the sides of the vehicle and does not have to be bundled like traditional wiring (a bundle of wires creates a circular cross section with a larger diameter whereas flat cable does not).

Finally, a communications network for a heavy-duty vehicle must be integrated based on system speed requirements, number of required ports, desired protocols, cable design, cable shielding levels, and connector attachments. That means connector suppliers must also be experts in systems design, preferably working as a team with the customers on initial communication systems designs. Selecting the right interconnect scheme, including overall resistance and shielding of the system, can be critical to creating 24/7 communications systems that help control heavy-duty vehicles now and in the future.

This article was written for SAE Off-Highway Engineering by Gregory LaMirand, Global Business Development Manager, Arnold Perry Tchiegne, Industry Marketing Manager, and Dan Prescott, Director, Key Accounts and Industry Marketing, Molex, LLC.

Continue reading »