Abstract: Methods, apparatus, systems, and computer program products for estimating error in an electric motor position sensor are disclosed. In a particular embodiment, an electronic control unit (ECU) for an electric motor receives, during a first state of operation of the electric motor, a first plurality of time samples of a first output signal from a position sensor, the first output signal indicative of a rotational position of the electric motor during the first state. The embodiment includes determining a first magnitude value for each of the first plurality of time samples of the first output signal, determining a first magnitude ripple value based upon the plurality of first magnitude values, and determining a first absolute angle error based on the first magnitude ripple value. The embodiment further includes determining an estimated error offset based on the first absolute angle error and storing the estimated error offset in a memory.

Abstract: According to one embodiment, a fluid level sensor apparatus for directly inserting into an oil-based fluid is disclosed. The apparatus comprises a sense element that includes a plurality of electrodes mounted on one side of a substrate. In this embodiment, the plurality of electrodes form at least two inter-digitated planar capacitors in which a capacitance of one of the inter-digitated planar capacitors varies as a function of the level of the oil-based fluid within a fluid cavity. The apparatus in this embodiment also includes a passivation layer covering the two inter-digitated planar capacitors and an oleophobic coating covering the glass barrier layer.

Abstract: A dielectric-constant-insensitive fluid level sensor for directly inserting into a high dielectric constant fluid is disclosed. According to one embodiment, the fluid level sensor includes a first set of stacked series capacitors where each capacitor in the first set is formed by two coplanar electrodes and a dielectric space between the electrodes. Each stack of series capacitors in the first set includes at least one capacitor having a first molded carrier as the dielectric space in series with another capacitor having a first fluid cavity as the dielectric space. In this embodiment, the total capacitance of the first set of stacked series capacitors varies as a function of the level of the fluid within the first fluid cavity.