A method for determining a change in a distance, a location prompting method and an apparatus and a system thereof are provided. The method includes: sending, by a receiving terminal, a paring request to a server for the server to forward the paring request to a transmitting terminal, and to allocate a frequency band for the receiving terminal and the transmitting terminal after the transmitting terminal accepts the paring request; acquiring, by the receiving terminal, an acoustic wave signal of a frequency sent by the transmitting terminal, wherein the frequency is determined by the transmitting terminal based on the allocated frequency band; determining, by the receiving terminal, a change in the acquired acoustic wave signal; and determining, by the receiving terminal, a change in a distance between the transmitting terminal and the receiving terminal according to the change in the acquired acoustic wave signal.

A method for determining a change in a distance, a location prompting method and an apparatus and a system thereof are provided. The method includes: sending, by a receiving terminal, a paring request to a server for the server to forward the paring request to a transmitting terminal, and to allocate a frequency band for the receiving terminal and the transmitting terminal after the transmitting terminal accepts the paring request; acquiring, by the receiving terminal, an acoustic wave signal of a frequency sent by the transmitting terminal, wherein the frequency is determined by the transmitting terminal based on the allocated frequency band; determining, by the receiving terminal, a change in the acquired acoustic wave signal; and determining, by the receiving terminal, a change in a distance between the transmitting terminal and the receiving terminal according to the change in the acquired acoustic wave signal.

A system for providing haptic feedback to a user, the system comprising a first piezoelectric transducer array comprising multiple piezoelectric transducers, respective ones of which being configured to generate a second signal at a second frequency, and at least one of which being configured to generate a first signal at a first frequency, and a second piezoelectric transducer array comprising multiple piezoelectric transducers, respective ones of which configured to receive the second signal, and at least one of which configured to generate a third signal to initiate generation of the first signal at the said at least one piezoelectric transducer of the first piezoelectric transducer array, the first frequency suitable for providing a haptic feedback signal for a user.

Systems and methods of estimating a location of a mobile computing device are provided. For instance, acoustic signals can be received from one or more transmitting devices associated with a real-time locating system. A set of peaks can be selected from the received acoustic signals. A first set of transmitter locations can be assigned to the selected set of peaks. The first set of transmitter locations can be specified by an acoustic model specifying a plurality of transmitter locations within an acoustic environment in which the one or more transmitting devices are located. A first model path trace associated with the first set of transmitter locations can be compared to the received acoustic signals. A location of the mobile computing device can be estimated based at least in part on the comparison.

Systems and methods of estimating a location of a mobile computing device are provided. For instance, acoustic signals can be received from one or more transmitting devices associated with a real-time locating system. A set of peaks can be selected from the received acoustic signals. A first set of transmitter locations can be assigned to the selected set of peaks. The first set of transmitter locations can be specified by an acoustic model specifying a plurality of transmitter locations within an acoustic environment in which the one or more transmitting devices are located. A first model path trace associated with the first set of transmitter locations can be compared to the received acoustic signals. A location of the mobile computing device can be estimated based at least in part on the comparison.

A method for determining an actual position of a microphone, comprising: sequentially emitting a first sound signal via a first speaker positioned and a second sound signal via a second speaker positioned; measuring a first elapsed time between the emission of the first sound signal and a detection of the first sound signal by the microphone, and a second elapsed time between the emission of the second sound signal and a detection of the second sound signal by the microphone; determining a first distance between the first speaker and the microphone using the first elapsed time, and a second distance between the second speaker and the microphone using the second elapsed time; determining the actual position of the microphone using the first and second distances and the positions of the first and second speaker; and outputting the actual position.

A method for determining an actual position of a microphone, comprising: sequentially emitting a first sound signal via a first speaker positioned and a second sound signal via a second speaker positioned; measuring a first elapsed time between the emission of the first sound signal and a detection of the first sound signal by the microphone, and a second elapsed time between the emission of the second sound signal and a detection of the second sound signal by the microphone; determining a first distance between the first speaker and the microphone using the first elapsed time, and a second distance between the second speaker and the microphone using the second elapsed time; determining the actual position of the microphone using the first and second distances and the positions of the first and second speaker; and outputting the actual position.

A head mounted display device and a positioning device thereof are provided. The positioning device includes a first sensor, a second sensor, a third sensor, a first hinge sensor, and a controller. The first sensor and the second sensor have a fixed relative location. The third sensor is disposed on a first flexible member of the head mounted display device. The first hinge sensor is disposed on a first connecting portion configured to connect a main body portion and the first flexible member, wherein the first hinge sensor is configured to sense a first movement state of the first flexible member. The controller is configured to calculate a first relative location information of the first sensor, the second sensor, and the third sensor, and to calibrate the first relative location information according to the first movement state.

A head mounted display device and a positioning device thereof are provided. The positioning device includes a first sensor, a second sensor, a third sensor, a first hinge sensor, and a controller. The first sensor and the second sensor have a fixed relative location. The third sensor is disposed on a first flexible member of the head mounted display device. The first hinge sensor is disposed on a first connecting portion configured to connect a main body portion and the first flexible member, wherein the first hinge sensor is configured to sense a first movement state of the first flexible member. The controller is configured to calculate a first relative location information of the first sensor, the second sensor, and the third sensor, and to calibrate the first relative location information according to the first movement state.

Systems and methods of providing location-based functionality using acoustic location determination techniques are disclosed. For instance, acoustic signals can be received from one or more transmitting devices associated with a real-time locating system. A location of a mobile computing device can be determined based at least in part on the received acoustic signals. One or more actions to perform can be determined based at least in part on a control scheme associated with the real-time locating system and the determined location. The one or more actions can be performed.