Sensor technologies and sensor applications have a long and successful tradition with Continental Automotive. Reliable, innovative, high-performing, robust, and economic sensor solutions provide the basis for many safety-relevant functions in the car. For decades, Continental Automotive has developed and industrialized sensors for advanced safety and motion applications.
We call this “empowering sensors” because using a sensor for a new application means widening the capabilities of that sensor and its technology. This can be done in several ways. In some cases, it is all about using a sensor cell and industrializing it for the specific requirements of a new automotive application. A core part of that is to balance the performance, the production cost and cost in general while ensuring the highest quality and reliability.
Another way of empowering a sensor is to improve its performance, for instance, by adding clever software. For both strategies to empower a sensor there are attractive new examples. Read on!
In short: Readying sensors for new applications and improving their performance is one of Continental Automotive’s long-standing strengths.
For many applications a sensor is chosen to deliver the precision that is needed for the job – Electronic Stability Control (ESC) provides a perfect example. The MEMS inertial sensor cluster in the Airbag Control Unit (ACU) provides the signal combo for keeping the vehicle stable. It is an established, well-working and reliable solution.
However, what if the sensor cluster signals are perfect for one solution but not for another that requires greater precision?
Not just one use case comes to mind:
- Highly Automated Driving (HAD) requires very exact sensor readings, for instance, to safely perform the Minimum Risk Maneuver.
- Positioning the vehicle in its lane requires precision as the basis for defining the trajectory.
- Safe and comfortable driver assistance such as Headlight Levelling (HLL) also benefits from better signals.
Does this mean moving on to a more costly sensor technology? No – there is a smarter way!
In short: While every sensor combo has its limits, Integrated Sensor Enhancement shows ways to overcome them.
Algorithms Empower the Sensor Cluster
Continental Automotive is developing a set of algorithms which adjust the ACU sensor signals by checking them against longitudinal and lateral models. As a result of extended filtering and correlation with further signal sources, the Integrated Sensor Enhancement (ISE) provides a second signal-out with an adjusted combo signal. This signal’s precision is better by a magnitude than the unfiltered signal used for, e.g., ESC:
During ISE function validation in a vehicle the worst-case sensor offset was thus reduced from 1 m/s2 for acceleration and 3°/s for angular rates to an impressive <0.05 m/s2 for Z acceleration and <0.05 °/s for angular rate. X and Y acceleration were reduced to 0.1 m/s2.
This precision is achieved within the first 20 minutes of vehicle operation because the ISE is a learning system: It adapts to the actual offset of the individual sensor cluster and compensates it through filtering. The system is self-monitoring and recognizes its level of learning.
So, by adding clever algorithms to an existing and proven MEMS sensor cluster a new function such as Headlight Levelling (HLL) gets the signal-in it requires.
In short: Sensor cluster and ISE software are a winning team!
A very efficient counter strategy to road noise is active noise cancellation, a function that is very popular in earphones, for instance. Road Noise Cancellation dampens noise from the environment by emitting inverted soundwaves: When both waves meet, they neutralize each other. It takes powerful computation to calculate and produce an inverted sound wave fast enough to cancel noise. The signal for Road Noise Cancellation comes from acceleration sensors. Continental Automotive is readying a sensor with specific parameters for this increasingly popular application.
In short: Road Noise Cancellation is more efficient than just sound-proofing. To make this work, the sensor picking up the road-induced vibration needs to be carefully selected.
Reconciliating Performance and Economy in a g-Sensor
Initially, Road Noise Cancellation was a technology mostly found in luxury cars. In the meantime, however, the function is increasingly available in the other segments as well. This kind of transfer requires a delicate balance between sensor properties and cost.
Continental Automotive brings its vast g-sensor know-how to active Road Noise Cancellation. This know-how stems from industrializing and mass-producing crash sensor satellites on very efficient production lines.
For active Road Noise Cancellation, the acceleration signal from the sensor needs to have a very low latency to give the control enough time for calculating and generating the inverted sound wave. The 3-axis low-g sensor selected for this function has a range of ±16 g and a high sensitivity of <2 mg/LSB. The signal is transmitted via high-speed communication with a dedicated bus.
The oncoming Road Noise Cancellation satellite sensor from Continental Automotive combines the required technical parameters with the economic scales of mass-production on efficient lines. The robust satellite sensor (cell, housing, pins) is designed for mounting on the chassis in the wheel area.
In short: Continental Automotive is readying a carefully chosen Acceleration Sensor for the new function of active Road Noise Cancellation.