Different types of motion encountered in dynamic environments require designers to specify connectors for boards, wiring, and devices that can meet significant g-forces, vibrations, and weight challenges. Advanced connectors designed to handle dynamic forces were introduced in the 1970s to meet the needs of aerospace applications. In the early 1990s, the extreme speed and vibration in Formula One, NASCAR, Indycar, and Le Mans cars inspired the development of advanced interconnection solutions for autosports.
Today, the vision for applying robust connector technology is expanding from racecars to robotics in the form of autonomous vehicles. Driving this adoption are design and materials developments that reduce connector weight as much as 20% to 30% compared to standard designs. Engineering innovations are also producing new, high-density connectors that meet the extreme weight, vibration, and data requirements of state-of-the-art racecars and robots.
Minimizing Weight While Maintaining Reliability
A basic challenge for any dynamic application is maintaining connector reliability and robustness while minimizing weight. Balance of Performance tables stipulate weight requirements in racecars, while robots aim to reduce weight to increase battery life and operational range. For connectors, a key weight-reduction factor is minimizing metalwork; for example, a standard aerospace four-hole circular connector requires a backshell to support the cable. Weight can be reduced by using a two-hole flange, and in place of a backshell, using a heat-shrink-molded boot with an adhesive coating. The boot solution forms a watertight seal and helps protect the cable from corrosion and mechanical abuse while providing excellent electrical insulation. Both of these changes can shave 20% off the weight of the standard design while improving performance and robustness. With more autonomous and robotic vehicles operating with sensors in water and dusty environments, optimizing both weight and reliability is essential to success.
Handling More Data and Current
The challenges become more complex when high data bandwidth and high current are involved. Mobile robot applications use high-bandwidth sensor modules. High-current solutions are employed in e-mobility drivetrains, electric motors, and servos.
To create a connectivity solution, TE Connectivity uses DEUTSCH MIL-C-38999 Series 1.5 (Eurofighter connector) as a starting point to develop connectors designed especially for the autosports market. For sensor connections, an ASX series form factor offers an extremely small and light package for three, five, and six wires. They can be used with 55 wire high-performance cable featuring modified radiation cross-linked ethylene tetrafluoroethylene (ETFE) polymer and single-wall (or dual-wall airframe) construction for a thin solution for military and autosports electronics.
When employed with thin-wall boots and sleeving, the result is an extremely robust option for electrical harnesses that also reduces weight. Furthermore, Formula One cars and robots are utilizing ultra-thin 30 AWG wire, which just a few years ago would have seemed more like science fiction than practical reality.
When wiring a racecar or robot, today's designers can take advantage of many connector options backed by engineering support to ensure proper selection and application; for example, with data transmission, proper contact arrangement and properly matched cables and connectors in the harness are needed to avoid crosstalk. When choosing a connector, factors to consider are size, current capacities, conductor counts, and ease of use. Robot and racecar applications especially benefit from easy-to-assemble connector solutions that feature water and dust resistance. Robust autosports connectors are also designed to be mated and unmated many times, similar to connectors designed for earth-moving and industrial equipment.
What will connectors for autosports and robotic/autonomous vehicles look like in the future? It's difficult to tell because the pace of change in these applications is continuing to accelerate. More sensors using more data bandwidth are likely to be on the developmental road for the years ahead.
Great strides are being made in materials and form factors as 3D printing revolutionizes packaging with new designs that could not be manufactured previously. The challenges of connecting wiring, boards, sensors, and devices will continue to inspire more innovations in crimping and contacts. That's why designers of electronics in racecar, robot, and aerospace applications can look forward to more connector developments to ensure winning performance in harsh environments where speed and motion are extreme.
This article was written by Paul Webb, Autosport Global Product Manager for TE Connectivity, Hastings, UK. For more information, click here.