Sensor accuracy: Critical metric in automotive, industrial, consumer markets

By Maria Vetrano

As group vice president of the Analog & MEMS Group and general manager of the MEMS Sensor division at STMicroelectronics, Andrea Onetti brings nearly three decades of experience in MEMS, sensors and audio systems to his leadership role at one of the world’s most successful electronics and semiconductor manufacturers. During his keynote at FLEX and MEMS & Sensors Technical Congress 2019, February 18-21 in Monterey, Calif., Onetti will address the criticality of sensor accuracy in advancing automotive, industrial and consumer applications. SEMI’s Maria Vetrano spoke with Onetti recently to give FLEX/MSTC attendees a preview of his presentation.

SEMI: What are some promising advancements in sensors for autonomous cars?

Onetti: The avionics industry is already successfully applying sensors for autonomous operationl. Inertial navigation systems (INS) support the operation of planes during flight, both after takeoff and before landing. Unfortunately, the technology in these navigation systems is expensive and not scalable, and they are hampered by reliability limitations in an automotive environment.

Following the steady progress that we have made with MEMS inertial sensors in consumer applications, we are on the cusp of realizing greater accuracy in temperature and time – finally delivering the performance required for autonomous driving. Because we can scale in production – we’re now manufacturing more than a billion units a year – we can select the cream of this production crop for adoption in cars. Consequently, we should see Level 3 and Level 4 autonomous driving for consumers very soon.

SEMI: How are companies using sensors to monitor and track their assets in industrial applications?

Onetti: Predictive maintenance and asset tracking are the two main verticals in Smart Industry. The adoption of multiple sensors for condition monitoring is helping to detect the faulty operation of equipment and to detect early signs of issues that are otherwise difficult to capture.

Ultrasonic microphones can detect leaks in a pipe at an early stage, accelerometers with high bandwidth can act as micrometers, and accurate temperature sensors can catch overheating.

Similarly, in asset tracking, we use temperature monitoring in combination with inertial sensors to detect problems during the transport of goods. Shock sensors with extremely high full scale (up to 8000g) can tell whether a lightweight envelop has been dropped. Pressure sensors can switch off a radio system when a cargo plane takes off and can mute smart trackers in compliance with flight regulations. We really can do almost anything!

SEMI: How will sensors advance user experiences in consumer electronics, such as VR/AR systems?

Onetti: Virtual reality (VR) and augmented reality (AR) are great examples of promising consumer technologies that will become pervasive as performance of inertial sensors improves. First, we need super accuracy in time and temperature to provide the right experience to users. To achieve this level of accuracy, we need a major step forward in performance, and that includes power consumption and miniaturization. Fortunately, we are constantly making progress in the high-accuracy motion, environmental and proximity sensors that are critical to these systems. While the scale is vastly different between VR/AR and automotive, the requirements for AR/VR systems are pretty similar to those that will enable autonomous cars.

SEMI: We don’t hear much about the criticality of higher accuracy in sensors. Why is improving accuracy in sensors especially important – and what role do calibration routines play in achieving higher accuracy?

Onetti: A sensor is more than just the performance of the relevant function. It is also the intrinsic accuracy that it brings. This accuracy is tuned by calibration, which is typically an expensive process done at the end of product manufacturing or – better still – during earlier stages of manufacturing.

Today more applications require sensors with higher accuracy, which necessitates investing more time in calibration, leading to higher cost.

MEMS technology can help by offering solutions with intrinsic higher accuracy, which reduces the cost of calibration for product manufacturers. This naturally delivers major benefits to OEMs and, ultimately, their customers.

SEMI: What would you like FLEX and MSTC attendees to take away from your presentation?

Onetti: As attendees explore the wide variety of available sensor solutions for their end products, I would ask them to prioritize the role of accuracy in sensor selection – because improved accuracy means higher quality data, and higher quality data means better decisions with reduced need for data processing.

While designers understand the role of calibration routines in qualifying individual components for specific applications, it is the continuous evolution of MEMS technology that offers the best possibility of breakthrough reductions in time and cost of these calibration routines. This makes MEMS sensors more attractive and affordable than similar sensor components based on different technologies.

Source: SEMI Blog