Detection and signaling of conditions of an unmanned aerial vehicle
A condition of an unmanned aerial vehicle (UAV) is detected using one or more sensors of the UAV and signaled according to an alert definition associated with the condition. For example, an alert definition can indicate to signal the condition by using a motor of the UAV to produce an audible tone. A tonal signal having a frequency within an audible spectrum can be generated according to the alert definition. The tonal signal and a drive signal used for supplying current to the motor can be combined to produce a combined signal. The combined signal can then be transmitted to the motor to cause the motor to produce the audible tone. In some cases, an amplitude of the tonal signal can be modulated, such as where the amplitude of the combined signal exceeds a threshold associated with an operating margin of the UAV.
1. A method for detecting and signaling a condition of an unmanned aerial vehicle, the method comprising:
detecting the condition using one or more sensors of the unmanned aerial vehicle;
identifying an alert definition associated with the condition, the alert definition specifying an audible tone for signaling the condition;
generating an alert according to the alert definition, the alert including a tonal signal having a frequency within an audible spectrum;
combining the tonal signal and a drive signal to produce a combined signal, the drive signal supplying current to a motor of the unmanned aerial vehicle; and
signaling the condition by causing the motor to produce the audible tone using the combined signal.
2. The method of claim 1 , wherein identifying the alert definition associated with the condition comprises:
querying a database based on data indicative of the condition, the database storing records associated with a plurality of alert definitions including the alert definition.
3. The method of claim 1 , wherein combining the tonal signal with the drive signal to produce the combined signal comprises:
combining a first amplitude corresponding to the frequency of the tonal signal and a second amplitude corresponding to a frequency of the drive signal to produce a combined amplitude;
determining that the combined amplitude exceeds an amplitude threshold, the amplitude threshold associated with an operating margin defined for the motor; and
responsive to determining that the combined amplitude exceeds the amplitude threshold, modulating the first amplitude to cause the combined amplitude to not exceed the amplitude threshold.
4. The method of claim 3 , further comprising:
defining the operating margin based on a maximum amount of current that can be supplied to the motor using the drive signal.
5. The method of claim 4 , wherein the maximum amount of current that can be supplied to the motor changes over time during operation of the unmanned aerial vehicle.
6. The method of claim 3 , wherein the amplitude threshold represents a maximum signal amplitude that can be transmitted to the motor without saturation.
7. The method of claim 1 , wherein the combined signal includes an amplitude corresponding to the frequency of the tonal signal, and wherein causing the motor to produce the audible tone according to the combined signal comprises:
transmitting the combined signal from a motor controller to the motor; and
causing the motor to vibrate according to the amplitude.
8. The method of claim 1 , wherein the condition reflects the unmanned aerial vehicle entering a free-fall state.
9. The method of claim 1 , wherein the frequency of the tonal signal is distinct from frequencies of the drive signal.
10. An unmanned aerial vehicle, comprising:
a detection system including one or more sensors for detecting a condition of the unmanned aerial vehicle;
a motor controller including a tonal control mechanism and a signal mixer, wherein the tonal control mechanism generates a tonal signal subsequent to receiving data associated with the condition from the detection system, and wherein the signal mixer produces a combined signal by combining the tonal signal and a drive signal; and
a motor that produces an audible tone using the combined signal subsequent to receiving the combined signal from the motor controller.
11. The unmanned aerial vehicle of claim 10 , wherein the detection system includes a database for storing an alert definition indicating to signal the condition by producing the audible tone, wherein the database is queried based on data indicative of the condition to identify the alert definition.
12. The unmanned aerial vehicle of claim 10 , wherein the motor controller includes a scaling control mechanism that:
combines a first amplitude corresponding to a frequency of the tonal signal and a second amplitude corresponding to a frequency of the drive signal to produce a combined amplitude;
determines that the combined amplitude exceeds an amplitude threshold, the amplitude threshold associated with an operating margin defined for the motor; and
responsive to determining that the combined amplitude exceeds the amplitude threshold, modulates the first amplitude to cause the combined amplitude to not exceed the amplitude threshold.
13. The unmanned aerial vehicle of claim 12 , wherein the motor controller includes a margin control mechanism that indicates the operating margin based on a maximum amount of current that can be supplied to the motor using the drive signal.
14. The unmanned aerial vehicle of claim 13 , wherein the maximum amount of current that can be supplied to the motor changes over time during operation of the unmanned aerial vehicle.
15. A non-transitory computer-readable storage medium, comprising processor-executable routines that, when executed by a processor, facilitate a performance of operations at an unmanned aerial vehicle, the operations comprising:
combining a first amplitude corresponding to a frequency of a tonal signal and a second amplitude corresponding to a frequency of a drive signal to produce a combined amplitude;
determining that the combined amplitude exceeds an amplitude threshold;
responsive to determining that the combined amplitude exceeds the amplitude threshold, reducing the first amplitude;
subsequent to reducing the first amplitude, combining the tonal signal and the drive signal to produce a combined signal; and
causing a motor of the unmanned aerial vehicle to produce an audible tone using the combined signal.
16. The non-transitory computer-readable storage medium of claim 15 , wherein the audible tone is indicative of a condition of the unmanned aerial vehicle, the operation further comprising:
detecting the condition using one or more sensors of the unmanned aerial vehicle.
17. The non-transitory computer-readable storage medium of claim 16 , further comprising:
identifying an alert definition associated with the condition, the alert definition indicating to signal the condition by producing the audible tone.
18. The non-transitory computer-readable storage medium of claim 17 , wherein the operations for identifying an alert definition associated with the condition comprise:
querying a database for a record associated with the condition, the record corresponding to the alert definition.
19. The non-transitory computer-readable storage medium of claim 17 , further comprising:
generating the tonal signal according to the alert definition, wherein the frequency of the tonal signal is within an audible spectrum.
20. The non-transitory computer-readable storage medium of claim 15 , wherein the operations for causing the motor of the unmanned aerial vehicle to produce the audible tone using the combined signal comprise:
transmitting the combined signal to the motor, wherein the motor, subsequent to receiving the combined signal, vibrates according to the first amplitude.