A wearable device can include a wearable band configured to contact a user of the wearable device, an actuator, a sensor, and one or more processors in communication with the actuator and the sensor. The processors can be configured to measure a back electromotive force (“EMF”) of the actuator; determine, based on the measured back EMF, data that describes a contact force between the wearable band and the user; and determine, based on the data that describes the contact force, a quality metric describing a data quality of sensor data collected by the sensor. In some embodiments, the processor(s) can determine, generate sensor output data based on the sensor data and based at least in part on the data describing the contact force between the wearable band and the user. For example, one or more machine-learned models maybe leveraged to generate sensor output data that is compensated for the wearable band being too tight or too loose.

A haptic engine includes a gap-closing actuator having a double-wound driving coil in which the two windings can be activated with two driving sources, respectively. Or, the two windings double-wound driving coil can be activated with a single driving source when the two windings are connected with each other either in series or in parallel. By using the double-wound driving coil in the gap-closing actuator as described, an instant inductance of either of the two windings can be determined without having to measure in real time a resistance of the corresponding winding.

For efficient presentation of pseudo force sense, a pseudo force sense generation apparatus includes: a base mechanism; and a contact mechanism that performs periodical asymmetric motion relative to the base mechanism and gives force based on the asymmetric motion to skin or mucous membrane with which the contact mechanism is in direct or indirect contact. A mass of the contact mechanism is smaller than a mass of the base mechanism, or the mass of the contact mechanism is smaller than a sum of the mass of the base mechanism and a mass of a mechanism that is attached to the base mechanism.

For efficient presentation of pseudo force sense, a pseudo force sense generation apparatus includes: a base mechanism; and a contact mechanism that performs periodical asymmetric motion relative to the base mechanism and gives force based on the asymmetric motion to skin or mucous membrane with which the contact mechanism is in direct or indirect contact. A mass of the contact mechanism is smaller than a mass of the base mechanism, or the mass of the contact mechanism is smaller than a sum of the mass of the base mechanism and a mass of a mechanism that is attached to the base mechanism.

Provided is a user-friendly power tool. The power tool 1 comprises: a battery pack mount 2c to which a battery pack 4 can be attached and detached; and a cover 17 that can cover the battery pack 4, mounted on the battery pack mount 2c, and the battery pack mount 2c so as to allow opening and closing. The wall 23 of the battery pack mount 2c is provided with a correcting part 23a that is capable of correcting inward warping of both the left and right side surfaces of the cover 17, which are the longitudinal direction surfaces. The lower edge of the correcting part 23a has a rounded shape.

A linear vibration actuator includes: a mover having a plurality of magnets linearly arrayed in the vibration direction; a guide portion holding the mover to be allowed to linearly move in the vibration direction; a plurality of planar coils wound in a flat plate shape on a flat surface facing the mover; a pair of first biasing magnets respectively arranged at both ends of the mover in the vibration direction; and a pair of second biasing magnets that are respectively arranged facing the pair of first biasing magnets, and respectively have the same polarities as those of the pair of first biasing magnets to bias the mover in the vibration direction.

A sensor includes a radio frequency interrogator, a responsive patch, a radio frequency resonance detector, and a transmission line. The radio frequency interrogator is configured to produce an electromagnetic interrogation pulse having a first frequency. The responsive patch includes a substrate and a resonant layer disposed on a surface of the substrate. The substrate includes a polymer. The resonant layer includes an electrically conductive nanomaterial. The resonant layer is configured to resonate at the first frequency in response to receiving the electromagnetic interrogation pulse. The radio frequency resonance detector is configured to detect a resonating response of the responsive patch. The transmission line couples the responsive patch to the radio frequency resonance detector. The transmission line is configured to transmit the resonating response of the responsive patch to the radio frequency resonance detector.

For efficient presentation of pseudo force sense, a pseudo force sense generation apparatus includes: a base mechanism; and a contact mechanism that performs periodical asymmetric motion relative to the base mechanism and gives force based on the asymmetric motion to skin or mucous membrane with which the contact mechanism is in direct or indirect contact. A mass of the contact mechanism is smaller than a mass of the base mechanism, or the mass of the contact mechanism is smaller than a sum of the mass of the base mechanism and a mass of a mechanism that is attached to the base mechanism.

For efficient presentation of pseudo force sense, a pseudo force sense generation apparatus includes: a base mechanism; and a contact mechanism that performs periodical asymmetric motion relative to the base mechanism and gives force based on the asymmetric motion to skin or mucous membrane with which the contact mechanism is in direct or indirect contact. A mass of the contact mechanism is smaller than a mass of the base mechanism, or the mass of the contact mechanism is smaller than a sum of the mass of the base mechanism and a mass of a mechanism that is attached to the base mechanism.

A method of providing a haptic signal is described therein, the method comprising the steps of providing a first source signal, filtering a mid-range band of the first source signal for restricting a bandwidth of the first source signal to the mid-range band, integrating the filtered mid-range band of the first source signal to identify an amplitude of the filtered first source signal, providing a voltage control amplifier with a proportional calibrated voltage on a basis of the integration of the filtered first source signal for adjusting an amplitude of the filtered source signal, isolating a trans-conductance voltage control amplifier high impedance output from a second source signal with a buffer, filtering the filtered source signal with a low pass filter to identify original sub-frequencies of an audio program and combining the identified original sub frequencies of the audio program with transposed midrange frequencies in a haptic signal.