System and methods for adaptively determining turbocharger speed

A speed sensing device comprising:

• a substrate;
• an acceleration sensing arrangement to output measured acceleration output signals, the acceleration sensing arrangement being disposed on the substrate;
• an acoustic sensing arrangement to output measured acoustic output signals, the acoustic sensing arrangement being disposed on the substrate;
• a communications interface;
• a control module coupled to the acceleration sensing arrangement, the acoustic sensing arrangement and the communications interface to:
• determine an acceleration speed value based at least in part on the measured acceleration output signals;
• determine an acoustic speed value based at least in part on the measured acoustic output signals;
• provide the acceleration speed value to the communications interface for output as a current speed value when the acceleration speed value is stable;
• provide the acoustic speed value to the communications interface for output as the current speed value when the acceleration speed value is unstable and the acoustic speed value is stable;
• and
• provide an estimated speed value to the communications interface for output as the current speed value when both the acceleration speed value and the acoustic speed value are unstable.

A method of determining a rotational speed associated with a turbocharger, the method comprising:

• determining, by a control module of a device mounted to the turbocharger, a first speed value based on first output signals from an acceleration sensing arrangement of the device;
• determining, by the control module, a second speed value based on second output signals from an acoustic sensing arrangement of the device;
• outputting, by the control module via a communications interface of the device, the first speed value as the rotational speed when the first speed value is stable;
• and
• when the first speed value is unstable:
• outputting, by the control module via the communications interface, the second speed value as the rotational speed when the second speed value is stable;
• and
• outputting, by the control module via the communications interface, an estimated value as the rotational speed when the second speed value is unstable.