The changing mood in auto internal lighting
Last year, the Chevrolet 2016 Camaro brought a new concept, called ‘dynamic ambient lighting’, to the auto internal lighting market. Known as ‘Interior Spectrum Lighting’, the system offers 24 different ambient lighting effects throughout the interior of the car, including door panels, dashboard, and even cup holders.
The interior lighting can be customised, with different colours assigned to different driving modes. In park mode, the model even offers a ‘car show’ mode, whereby changing colours flow outwards from the instrument panel to the rest of the interior.
Meanwhile, earlier this year, at CES 2017, Toyota revealed its Concept-I vehicle, which features an AI assistant – named Yui – which uses light and sound to communicate with the driver. For example, coloured lighting illuminates the footwell to indicate whether the vehicle is in manual or self-driving mode. The exterior of the car also uses light to communicate with driver and surroundings.
Other automakers are following suit, and turning their attention to the development of interior lighting concepts as a means of brand differentiation. With increasing pressure on automakers to deliver fuel-efficient, low-emission engines, speed and performance is becoming less of a differentiator, so many see ambient lighting as the next battleground.
Furthermore, with advances in technologies such as ADAS, and the potential of self-driving cars, interior lighting design is set to become increasingly important, from both a mood and an entertainment perspective.
As well as using lighting to better communicate information, studies have shown that ambient lighting can influence the mood, eye fatigue, circadian rhythms and concentration of drivers… and so, ultimately, safety.
In 1995, for example, the average car had just four interior lights, all incandescents. Today, however, that number is nearer to 20, usually with a mix of incandescents and LEDs. Put simply, ambient lighting makes a statement, as well as affecting the driving experience.
Automakers already know that colour and lighting goes much deeper than mere visual impression. A variety of emotions can be invoked by using certain colours and hues. At the same time, the ability to personalise and customise the interior design of a car creates a greater emotional attachment within the owner.
For example, a landmark study in 2009, performed by BMW engineers and the Lighting Engineering Group at Ilmenau University of Technology in Munich, revealed that interior auto lighting can influence driver emotions and fatigue.
Surprisingly, it found that blue lighting appears ‘brighter’ to drivers than orange lighting, but was considered more "uncomfortable." In comparison, orange ambient lighting gave the perception of luxuriousness and better quality. Unsurprisingly, the brighter the light, the more distracting it became.
The same study found that ambient lighting was shown to enhance night-driving safety and increase appreciation of the vehicle. The study also indicated that ambient lighting can enhance the perception of spaciousness and quality of materials, which is why high-end manufacturers, such as Audi, Cadillac, Infiniti, Jaguar, Mercedes-Benz, and BMW, are using LED ambient lighting to differentiate their vehicles, but the trend is quickly filtering down to lower cost brands.
As a result, significant growth is expected in the auto ambient lighting sector with Markets and Markets predicting that the automotive lighting market will grow at a CAGR of 10.71%, from $46.48 billion in 2016 to $96.09 billion by 2023.
Meanwhile, Transparency Market Research predicted that the same market would expand at 8.10% CAGR from 2015 to 2021, reaching a value of $34.1 billion by 2021.
LED lights are leading the charge, thanks to their small size, low cost, and energy efficiency. But there is also a trend away from single coloured lighting to designs that incorporate two, three and even four colours. The use of LEDs in combination with multi-colour chips expands the options even further.
It’s likely that innovation will come thick and fast. LED’s could create not only moods, but also effects, such as ‘sparks’ and ‘floating’ light effects.
It’s likely that other light sources will start to find their niche in internal lighting too. Halogen, electroluminescence, and cold-cathode fluorescent (CCFT) offer specific use cases.
Halogens are starting to appear in concept designs, notably in ‘light engines’, which can be single source lights or ‘lamp clusters’ that consist of fiber-optic cables that allow for ‘spot’ lighting or ‘pools’ of light away from the light source for instrument lighting or ambient mood lighting. They can create more uniform light with fewer lights, and are particularly suitable for lighting ‘ornamental’ features such as visors and visor mirrors.
Such lighting is being used not just for sculpting and illuminating auto interiors, but also to create ‘lighting strips’ that better orientate the driver within the cockpit at night, creating intuitive lighting that guides the driver to drink holders or smartphone sockets, for example, without them losing concentration on the road ahead.
At the same time, the use of different materials can create different effects, for example, matte, glossy or chrome. The use of surface-mount LEDs is now more cost-effective, alloing designers to place lights where it was not possible before. As they are five times brighter than embedded LEDs, surface-mount lighting is being used for illumination purposes as well as to create ‘3-D’ indicators and displays.
To enhance the design options further, light-shaping diffusers and lenses can create further beam-shaping effects, such as diffracted or striated light and ‘hot spots’, as well as reducing shadow areas and controlling glare. The light-shaping properties of these materials can create eye-catching and unique patterns on dashboards, panels, ceilings, trimmings and anywhere else within the driving environment.
New polycarbonate film materials, meanwhile, can add 3-D effects to create ‘floating’ displays, markings, logos and information data. The image can appear to be behind or in front of textures, depending on whether the LED is positioned to the side or below the film.
In future, the options are only going to become more sophisticated and complex, particularly when it comes to autonomous vehicles. As well as providing expanded head-up displays (HUDs), lighting will enhance the information and entertainment experience in the cockpit, as well as ensuring optimum driver concentration and comfort.
Auto makers are also realising that drivers prefer to adjust lighting, and lighting levels, by gesture, rather than manually, which opens up a whole new world of gesture-recognition ambient and illumination lighting.
At the same time, dynamic lighting may be used in semi-autonomous vehicles to alert the driver to hazards, or when they need to retake control of the steering wheel. So, for example, ambient lighting may be one hue when the vehicle is in autonomous mode, but that colour changes when the vehicle has important navigation or hazard information to relay to the driver, or when it considers that the driver needs to take control back.
Of course, the interior experience will be the main focus in autonomous vehicles, setting the mood for all occupants, depending on whether they want to relax, sleep, or enjoy their infotainment choices. Ambient lighting will also be used to relay information to passengers, regarding safety, vehicle status, driving mode, navigation, places of interest, and so on, and should even respond to changes in outdoor lighting or weather conditions.
Of course, HUDs will become even more important in autonomous vehicles, and again ambient lighting and illumination effects will become an important brand differentiator. Information is likely to be juxtaposed in the cockpit and on the windshield against the external environment, everything from lane change arrows to changes in route due to traffic conditions, for example.
Ambient and interior lighting is set to become the new battleground for automakers as the complete driving experience becomes the purchase driver for consumers, whether for luxury, infotainment or safety purposes. Furthermore, with the increasing introduction of ADAS and even autonomous vehicles it is set to become the primary brand differentiator, a fact that has not gone unnoticed by auto manufacturers.