Sensor degradation is intrinsically linked to the most crucial issue in the automotive design world: safety. Now add advanced driver assistance systems (ADAS) and autonomous vehicle designs to the equation, and the critical importance of sensor degradation becomes self-evident.
That’s why sensor degradation will be a panel discussion subject at the AutoSens Brussels 2020 event. Deloitte, National Physical Laboratory, Obsurver, and University of Coventry are going to be part of this panel discussion to be held on 13 October 2020.
EDN spoke with Robert Stead, managing director at Sense Media Group, to outline the fundamental facts about automotive sensor degradation.
Sensor degradation causes
First and foremost, what are the leading causes of sensor degradation in automotive environments? According to Stead, there are several potential sources of sensor system performance degradation. For a start, there is wear and tear around the external mounting locations of sensors, either behind the windshield, lighting cluster, or other protective layers.
Second, while sensors are designed according to automotive specifications, they are likely subject to some level of degradation over time due to the harsh operating environments. Other potential causes of performance degradation could come from other electronic system elements, aside from the sensor and software used in ADAS and autonomous vehicles.
Temperature and vibrations in harsh automotive environments can cause sensor degradation over time. Source: Research Gate
That, in turn, could lead to potential mis-learns and cause unintended performance degradation, Stead added. So, the next logical question is how automotive engineers can measure sensor degradation in a timely and efficient manner.
How to measure sensor degradation
According to Stead, science exists to design tests to evaluate sensor degradation, but to date, there haven’t been any large-scale studies to define how much and how quickly systems degrade. “Therefore, the extent to which this might impact fleet safety performance is unknown.”
There’s a general acceptance that degradation will happen, not suddenly and catastrophically, but more like a slow decline in ADAS performance. Still, it does need to be quantified. Several academic institutions are looking at this as part of their research programs. The startup Obsurver has begun trials and is looking to scale up the automotive sensor degradation measurements. “SAE International is also looking at this issue via a standards development working group,” Stead said.
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How to mitigate sensor degradation
Let’s assume that there is a small amount of sensor degradation. However, when multiplied by the number of cars with ADAS on the road and multiplied by the number of years they have been running, it will have an overall impact on the fleet’s safety that automotive engineers will need to mitigate. That’s why a system to monitor performance and warn the fleet manager about potentially dangerous performance degradation will be of great value.
Stead said that testing could be done as part of a regular service schedule, like the annual road test in many countries, or it could be done via ‘on-the-fly’ performance monitoring by a unit in the vehicle, or both. “Obsurver also has a recommended approach to sensor degradation measurements.”
Majeed Ahmad, Editor-in-Chief of EDN, has covered the electronics design industry for more than two decades.