Reactive tether spool
View Patent ↗A reactive tether spool comprises a drum, a signal cable, a drum actuator, a tension sensor, and a controller. The signal cable transports power and a control signal to a UAV. A controller receives a tension measurement from the tension sensor and controls the drum actuator to maintain a determined tension on the signal cable while performing at least one of the following: dispensing the signal cable; holding the signal cable steady; and collecting the signal cable.
1. A device comprising:
a carriage;
a drum rotatably mounted on the carriage;
a drum connector disposed on the drum;
a signal cable configured to transport power and a control signal, the signal cable having:
a first end of the signal cable configured to connect with the drum connector; and
a UAV connector on a second end of the signal cable, the UAV connector configured to connect with a UAV;
a drum actuator configured to rotate the drum;
a cable drum feed configured to align the signal cable to the drum;
a UAV feed configured to align the signal cable as it exits the device towards the UAV;
a tension sensor configured to measure the tension of the signal cable; and
a controller comprising:
at least one processor;
a tangible medium that is not a transitory propagating signal, the medium comprising instructions configured to cause the at least one processor to:
receive a tension measurement from the tension sensor; and
control the drum actuator to maintain a determined tension on the signal cable while performing at least one of:
dispensing the signal cable;
holding the signal cable steady; and
collecting the signal cable.
2. The device according to claim 1 , further comprising a power transfer circuit configured to deliver power to a UAV from a battery when power on the signal cable falls below a threshold value.
3. The device according to claim 2 , wherein the power transfer circuit is connected to the UAV connector.
4. The device according to claim 1 , further comprising a remote UAV power supply configured to provide the UAV power via the signal cable.
5. The device according to claim 1 , further comprising a command circuit configured to deliver a landing command to a UAV when power on the signal cable falls below a threshold value.
6. The device according to claim 1 , further comprising a command circuit configured to deliver a landing command to a UAV when power on the signal cable signal cable falls below a first threshold value and the power available on a UAV battery falls below a second threshold value.
7. The device according to claim 1 , further comprising a slip ring structure configured to transport a signal between the drum connector and the controller.
8. The device according to claim 1 , further comprising a slip ring structure configured to transport a signal between the drum connector and a communication device.
9. The device according to claim 1 , further comprises a motor controller and wherein:
the drum actuator is a motor; and
the instructions are further configured to cause the at least one processor to control the motor via the motor controller.
10. The device according to claim 9 , wherein the drum motor comprises at least one of:
a stepper motor;
a servo motor;
a solenoid; and
a switch.
11. The device according to claim 1 , wherein the cable drum feed comprises
a. a linear actuator configured to be controlled by the controller; and
b. a tether spooling pulley connected to a linear actuator.
12. The device according to claim 11 , wherein the linear actuator comprises a lead screw rotatable by a lead screw actuator.
13. The device according to claim 12 , wherein the lead screw actuator comprises at least one of:
a stepper motor;
a servo motor;
a solenoid; and
a switch.
14. The device according to claim 1 , further comprising an alignment pulley configured to align the signal cable between the drum and the UAV feed.
15. The device according to claim 1 , wherein the UAV feed comprises a pulley.
16. The device according to claim 15 , the UAV feed comprises a damper.
17. The device according to claim 1 , wherein the tension sensor comprises at least one of:
a load cell;
a strain gage transducer;
a tension sensing roller;
a piezo electric crystal; and
an angle sensor.
18. The device according to claim 1 , wherein the tension sensor is disposed between the cable drum feed and the UAV feed.
19. The device according to claim 1 , wherein the signal cable further comprises a cable component with a breaking strength in excess of 10 pounds.
20. The device according to claim 1 , wherein the signal cable comprises at least one of:
an electrical cable;
a optical cable; and
a coaxial cable.