In the past, most design consideration for automotive interior controls focused on the basic functionality of a limited number of switches on a simple dashboard. However, as automobile design evolves and more comfort and convenience features are added, attention is turning to the aesthetic characteristics of interior controls and switches.

With the advent of advanced electronic technology – something that drivers now expect as part of a vehicle’s interior – automotive engineers must take a more holistic approach when it comes to the design of their interface controls. This includes making sure the look and feel of the vehicle, performance, and safety are integrated from the inception of the design.

Just as important as the logos that distinguish different makes and models, how controls feel and sound have become integral to the marketing process of modern vehicles. With this in mind, engineers have a real opportunity to reinforce the overall brand identity of their vehicles, further contributing to the perception of quality to the driver.

For example, switches on a dashboard. In the early days when interior controls were primarily electromechanical, interior designers used robust pushbutton switches with relatively long travel time – referring to the distance required to actuate the switch. As automotive interior subsystems have transitioned from electromechanical to electronic, drivers now gravitate towards switches with less travel time. This is especially true for the mobile-first generation, whose members have grown up with handheld electronics and are more familiar with short-travel switches. To cater to the more electronically inclined driver, interface controls evolved to smaller tactile switches with much shorter travel. Although this may seem like a small fix, many drivers consider old-school, long-travel switches to feel manual, clunky, and of lesser quality.

Short-travel tactile switches usually include a metallic snap dome contact system, which provides the interface between the actuator and the switch housing. While metallic domes typically have longer life cycles and shorter travels than their silicon counterparts, design engineers should keep in mind that the switch will often produce an audible sound when accessed. This can be a challenge when trying to create a pleasant, noise-free environment for the driver, and something that engineers should take into account to comply with brand sound standards.

Touchscreens are now commonly used on a vehicle’s center console. Tactile screens often replace numerous, independent knobs and keys to power every desired action. Many premium brands are taking the first step in integrating smartphone displays on the screen of the car. This user interface (UI) is just as important to the car as details such as the leather lining and stitching or dashboard design. By combining low-profile tactile switches within a wider actuating superstructure, designers can create a large clickable area that allows the driver to control multiple functions on a single surface, while minimizing power consumption and distractions behind the wheel.

Flexible manufacturing
Automotive designers are moving more system control functions to switches attached to the steering column and steering wheel. Tactile switches can offer drivers a physical response to operation, preventing them from having to look at controls while driving.

Achieving a sleek design that integrates personal tech, smarter functions, and meets safety requirements is no easy feat, so incorporating a flexible manufacturing process is important. This enables the manufacturer to adapt key components in the switch construction to achieve the consistency in performance sought by the automotive design engineers – for example, the aforementioned metallic snap dome which houses the tactile switch, but often causes unwanted sound. Through a flexible manufacturing process, the dome’s characteristics can be adapted to meet the particular vehicle’s requirements, including actuation force, travel distance, snap ratio, tolerance, acoustics, and other haptic factors.

Consolidating the design and manufacturing process enables the engineer to define the structure and material selection best suited for a given application, based on the needs of the automobile at hand. Rather than using a pre-determined set of switch components, this customizable process allows engineers to fine-tune the switches and components in the vehicle for optimal performance.

Another key is the ability of the switch supplier to provide different product samples during design. This can help weed out possible variations expected in volume production and provide automotive engineers with a framework to accurately assess the performance and consistency of the switches under real-world conditions during the design phase.

As intuitive systems and personal technology interfaces become commonplace, attention needs to be given to the smallest characteristics of a car, factoring in feel, sound, comfort, and convenience. Fortunately, automotive engineers are beginning to take a more all-inclusive approach to design by implementing more ergonomics into the layout of controls and switches, for better feeling and functioning cars.

C&K Components

www.ckswitches.com

About the author: Eric Grange, market manager for automotive at C&K Components, can be reached at eric.grange@ck-components.com.