False Triggers in The Automotive World Are Usually Related To Environmental Influences
Electronics is well inking the future of automobiles and the automotive sector is driven by new connected and sensorladen technologies. Gesture Recognition, Proximity Sensors are driving automotive infotainment segment. One of the leading market-leaders of this segment is Vishay Intertechnology. Niloy from BIS in an extensive interview with Mohan Kannusamy | Director | Product Marketing |Vishay Intertechnology Optical Sensors Division discusses the company’s offering, the technical aspects, challenges and best practises and future trends shaping the Automotive sector. Edited Nub Below.
- Vishay’s major proximity sensor offerings and applications focus defining your leadership?
Vishay has a huge portfolio of proximity sensors that are used in a wide range of applications. In automotive systems, our sensors are used for display wakeup, gesture recognition, and force sensing. On the consumer side, they provide presence detection in smartphones, VR / AR headsets, TWS, and various IoT applications.
- How can one prevent false triggers in automotive applications and how different it is from creating solutions for Smartphones?
False triggers in the automotive world are usually related to environmental influences. Compensating for the effects of both temperature and ambient light (sunlight) is of key importance here. Vishay´s proximity sensors include both temperature compensation and sunlight cancellation features. Furthermore, a simple calibration step should be performed, where an initial offset is measured and is subtracted from subsequent measurements so that it is always the change in counts that’s acted upon. This will help account for the mechanical stackup and its tolerances (both at the assembly as well as over time), so these don’t cause false triggers. Similar factors also affect smartphone applications, with the difference being that automotive applications require a more robust package and sensor performance, as well as a higher sensitivity (resolution) to allow for more specific applications, such as force sensing.
- Gesture Recognitions, Proximity Sensors are driving automotive infotainment; in that scenario how forcesensing becomes crucial for today’s automotive demands?
With the increased use of touch-sensitive surfaces in cars — which are placed not only near the screen of the main infotainment system, but also on other materials and surfaces — there is a necessity to distinguish between an accidental brush over a button and an intentional button selection. By detecting the amount of displacement of these surfaces down to a few micrometres, it can be sensed that force is being applied to an area, thus validating the input event. Depending on the amount of displacement that the surface allows for, this sensing method can also open up possibilities for new input types.
- Touch-free interfaces have become popular among automotive design engineers. There is a growing demand for wake-on-approach feature-based applications for audio panels, navigation systems, and more. Proximity sensors role to enable these technologies?
Proximity sensors are designed for this purpose. Instead of requiring a distance measurement, detecting the presence of an object in front of a system can be done by monitoring the change in signal that the proximity sensor sees. The sensing distance can be fine-tuned through sensor settings and the choice of external infrared – emitters. The positioning of these emitters will define the sensing area.
- What are the key advantages of digital proximity sensors and how is Vishay catering its expertise?
The key advantage of digital proximity sensors compared to traditional analog sensors is that the circuitry required allowing an analog sensor to sense a large enough distance, while also being robust against environmental influences, is already integrated into Vishay’s proximity sensors. This allows for a device in a small form-factor that can be fine-tuned to a specific application over its registry settings, and if needed, through the use of external LEDs. Vishay’s expertise in both manufacturing components with a high optical efficiency and designing robust component packages has led to its ever-increasing portfolio of automotive-qualified sensors. Furthermore, the in-house IC design allows for the integration of new optical frontends, which can be adapted to the constantly evolving market requirements.
- To the technical approach, how force sensing can use high-sensitivity proximity sensors and examples of any specific applications?
Vishay’s automotive proximity sensors are increasingly being utilized as force sensing devices. The principle of operation is that the sensor is placed underneath a surface to which force will be applied. The sensor’s high sensitivity in the region of 3 mm to 10 mm above the sensor allows for small changes in the displacement of the surface to be detected. The amount of displacement of the surface above the sensor will relate to a certain force, and so a threshold for the amount of force that needs to be applied to trigger an event can be set. An example of such an implementation is in the center console of the Porsche Panamera, where buttons can be pushed on an otherwise sleek black surface.
- Susceptible to failure in temperature extremities, exposed to cutting fluids and chemicals for prolonged periods, makes proximity sensors brittle and cracked, their life span can be severely impacted. How can further technology know-how improve these challenges?
Operating at an extreme condition can of course damage any sensor. Vishay’s sensors are designed according to the market’s needs. For example, during the design phase of our automotive-qualified proximity sensors, the materials are carefully chosen to make sure they can withstand high temperatures and operate in robust conditions.
- What key factors customers look into while choosing the right proximity sensor?
Key factors are the necessary detection distance and the area that needs to be covered. Does more than one LED need to be connected in order to cover the detection area? If the addition of further sensors, such as an ambient light sensor, is required, this will play a role in sensor choice as well. Lastly, some sensors are more applicable than others in applications where power consumption plays a role.
