A tracking method is disclosed. The method may include displaying visual content on a screen. A base station may be stationary with respect to the screen while the visual content is being displayed. In contrast, one or more objects may move with respect to the screen while the visual content is being displayed. The one or more objects may be tracked so that the movement thereof may be used to alter the visual content. Such tracking may involve the base station and the one or more objects sending and/or receiving one or more ultrasonic pulses. The tracked object also determines information using an inertial sensor assembly that receives a synchronization signal coordinated with the one or more ultrasonic pulses. Time-difference-of-arrival and/or time-of-flight of the one or more ultrasonic pulses may then be used to estimate a relative location and/or a relative orientation of the one or more objects with respect to the base station in three dimensional space, so that the estimate is fused with information determined by the inertial sensor assembly using the synchronization signal.

A tracking method is disclosed. The method may include displaying visual content on a screen. A base station may be stationary with respect to the screen while the visual content is being displayed. In contrast, one or more objects may move with respect to the screen while the visual content is being displayed. The one or more objects may be tracked so that the movement thereof may be used to alter the visual content. Such tracking may involve the base station and the one or more objects sending and/or receiving one or more ultrasonic pulses. The tracked object also determines information using an inertial sensor assembly that receives a synchronization signal coordinated with the one or more ultrasonic pulses. Time-difference-of-arrival and/or time-of-flight of the one or more ultrasonic pulses may then be used to estimate a relative location and/or a relative orientation of the one or more objects with respect to the base station in three dimensional space, so that the estimate is fused with information determined by the inertial sensor assembly using the synchronization signal.

A positioning device operates in cooperation with a signal receiver for receiving a plurality of signal waves arriving from at least one synchronous transmission unit including a plurality of signal transmitters that operates in synchronization with each other. The positioning device includes: a time-of-arrival detecting unit for detecting time of arrival of each of the plurality of signal waves on the basis of a reception signal output from the signal receiver and a distance difference calculating unit for calculating a difference in distance from the plurality of signal transmitters to the signal receiver as a set of observation values on the basis of a difference in the time of arrival that has been detected; and a positioning arithmetic unit. The positioning arithmetic unit calculates a time series of an estimation state vector indicating position information of the signal receiver by executing a positioning arithmetic operation based on a nonlinear Kalman filter using a time series of an observation vector indicating the set of the observation values and known position information of the plurality of signal transmitters.

A relay point generation method and apparatus, and an unmanned aerial vehicle (UAV) are disclosed. The method includes: predicting a state of a target at a next moment; establishing a search range around the target according to the state of the target at the next moment; performing sampling within the search range, to obtain at least two location sampling points; and determining a relay point of the UAV at the next moment according to the state of the target at the next moment and the at least two location sampling points.

A relay point generation method and apparatus, and an unmanned aerial vehicle (UAV) are disclosed. The method includes: predicting a state of a target at a next moment; establishing a search range around the target according to the state of the target at the next moment; performing sampling within the search range, to obtain at least two location sampling points; and determining a relay point of the UAV at the next moment according to the state of the target at the next moment and the at least two location sampling points.

A device can determine its position in a communications system. A scalable solution permits multiple devices to be used in one area without detrimental effect on the accuracy or latency of the position determining. The communications system includes a first base station arranged to transmit a first signal to a second base station arranged receive the first signal and transmit a second signal to the first base station in response The first base station is arranged to receive the second signal and transmit a third signal to the second base station in response to the second signal delay time measuring unit, round trip time measuring unit, a base station timings unit and a calculating unit are used to calculate a first time difference of arrival based on a first round trip time, first delay time, second round trip time and a second delay time.

Systems and methods for determining a time difference are provided in the present disclosure. The systems includes a first base station configured to receive a first signal transmitted from a terminal and receive a second signal from a second base station. The systems may also include the second base station configured to receive the first signal transmitted from the terminal, and transmit the second signal after receiving the first signal. The systems may further include at least one processor configured to determine a time duration between the first base station receiving the first signal and receiving the second signal and determine the time difference between a first time period of the first signal transmitted from the terminal to the first base station and a second time period of the first signal transmitted from the terminal to the second base station based on a third time period and the time duration.

Systems and methods for determining a time difference are provided in the present disclosure. The systems includes a first base station configured to receive a first signal transmitted from a terminal and receive a second signal from a second base station. The systems may also include the second base station configured to receive the first signal transmitted from the terminal, and transmit the second signal after receiving the first signal. The systems may further include at least one processor configured to determine a time duration between the first base station receiving the first signal and receiving the second signal and determine the time difference between a first time period of the first signal transmitted from the terminal to the first base station and a second time period of the first signal transmitted from the terminal to the second base station based on a third time period and the time duration.

A tracking method includes displaying visual content on a screen of a head mounted display (HMD). One or more base stations may be stationary with respect to the screen while the visual content is being displayed. In contrast, one or more objects may move with respect to the screen while the visual content is being displayed. Time-difference-of-arrival (TDoA) and/or time-of-flight (ToF) may be measured for one or more ultrasonic pulses transmitted from the base station, one or more objects, or HMD. Position and orientation of the objects and HMD may be calculated based on the TDoA and ToF. Different frequencies of pulses may be used to locate the HMD and the objects. An electromagnetic synchronization signal from the HMD and/or base station may be used to measure TDoA. Position and orientation measurements may be fused with outputs from IMUS (inertial measurement units) to reduce jitter.

A tracking method includes displaying visual content on a screen of a head mounted display (HMD). One or more base stations may be stationary with respect to the screen while the visual content is being displayed. In contrast, one or more objects may move with respect to the screen while the visual content is being displayed. Time-difference-of-arrival (TDoA) and/or time-of-flight (ToF) may be measured for one or more ultrasonic pulses transmitted from the base station, one or more objects, or HMD. Position and orientation of the objects and HMD may be calculated based on the TDoA and ToF. Different frequencies of pulses may be used to locate the HMD and the objects. An electromagnetic synchronization signal from the HMD and/or base station may be used to measure TDoA. Position and orientation measurements may be fused with outputs from IMUS (inertial measurement units) to reduce jitter.