POLYN ships VibroSense silicon for automotive evaluation

POLYN Technology has begun delivering engineering versions of its VibroSense TMS chip for assembly into automotive tyre sensor nodes, moving the neuromorphic analogue device into customer evaluation. The chip processes vibration data inside the tyre and estimates peak friction coefficient, giving vehicle control systems an additional measurement of available grip.

A tyre-mounted sensor node supplies raw accelerometer data to VibroSense, which produces a PFC estimate for the changing road surface beneath each wheel. The result is then transmitted wirelessly to the vehicle ECU as a sensor signal that can be used alongside existing inputs for braking, electronic stability control, all-wheel drive, driver assistance, and automated-driving functions.

Processing the vibration stream at the wheel reduces the amount of raw data that has to be transmitted elsewhere in the vehicle. That is useful in a sensor node with restricted power, communications bandwidth, package volume, and thermal headroom, but it also places more responsibility on the local silicon. The device has to produce repeatable outputs while tyres, pressure, load, temperature, wear, road surface, and vibration conditions change.

POLYN describes VibroSense as an application-specific Neuromorphic Analog Signal Processing device. Rather than relying on a general-purpose processor to handle the entire sensor workload, the architecture is intended to perform its trained signal-processing function close to the accelerometer. The commercial test is therefore whether the chip can produce consistent results within the environmental and manufacturing limits of an automotive sensor.

Calibration remains part of that task. POLYN says the system can be applied across tyre brands, with calibration required for each tyre type to account for its vibration signature. A production programme would also have to control variation between sensor assemblies, mounting positions, tyres, and electronic components while maintaining sufficient accuracy as the tyre wears through its service life.

The company has published results from a third-party braking test on wet basalt pavement. A vehicle using VibroSense-derived information stopped from 40km/h in 55.5 metres, compared with 63.2 metres without the system, a reduction of 12%. The figures describe one defined test rather than a universal braking improvement, but they provide prospective customers with a system level result that can be reproduced and challenged during evaluation.

The sensor node architecture also has to coexist with the tyre-pressure functions already expected from TPMS hardware. POLYN says its output can be delivered to the vehicle ECU as a standard sensor signal and that no mechanical changes to the vehicle are required for the grip measurement. That simplifies the integration proposition, although each customer still has to establish wireless behaviour, update strategy, diagnostics, and compatibility with its existing chassis-control architecture.

Engineering silicon now gives tyre manufacturers, vehicle makers, chassis suppliers, ADAS developers, and autonomous-driving companies hardware on which to run that work. Evaluation can cover signal quality, calibration, wireless integration, power consumption, packaging, temperature behaviour, electromagnetic compatibility, and the interaction between the PFC output and existing vehicle-control software.

Automotive qualification will extend well beyond those early demonstrations. Tyre electronics operate in a severe mechanical environment, with continuous vibration, large temperature changes, moisture exposure, centrifugal force, and long service intervals. A sensing function that may influence braking or stability decisions also has to be characterised carefully for fault behaviour, diagnostic coverage, and the consequences of stale, missing, or inaccurate data.

The programme remains preproduction. POLYN’s current timetable calls for tapeout of a commercially available chip in mid-2027, followed by automotive qualification. The engineering nodes are therefore a bridge between the present silicon and a qualified product rather than an announcement of immediate vehicle deployment.

Production decisions can now be based on real sensor nodes and measured vehicle behaviour, while POLYN still has time to incorporate findings into the commercial implementation. For a device intended to infer road grip from vibration inside a rotating tyre, the difficult work now shifts from demonstrating the principle to proving that it remains dependable across the range of conditions found on real vehicles.