Ultrasonic tracking system

A system for permitting a device to point at and track the movements of a moving subject, comprising:

• a. a transmitting unit to be worn by the subject to be tracked, for transmitting pulsed ultrasound signals which can be tracked;
• b. means including three sensors for receiving signals from the transmitting unit and for generating, in response to differences in arrival time of transmitted signals at the multiple sensors, tilt control signals and panning control signals;
• c. a device mounting member;
• d. the sensors being located in fixed relation to the device mounting member;
• and
• e. a vertical drive unit and a horizontal drive unit for respectively tilting and panning the device mounting member in response to respective tilt and panning control signals, to maintain the device pointed at the subject when the device is mounted on the mounting member.

Apparatus for maintaining a device pointed at and tracking the movements of a moving subject who is carrying a transmitting unit which emits recognizable pulsed ultrasonic signals, comprising:

• a. a device mounting member;
• b. means including sensors located in fixed relation to the device mounting member for receiving the signals emitted by the transmitting unit and for generating, in response to differences in the arrival times of said signals at multiple sensors, control signals;
• and
• c. a drive unit for moving the device mounting member in response to the control signals, to maintain the device pointed at the subject when the device is mounted on the mounting member.