The Autopilot Systems: Examples of Devices Essay

Introduction

This paper examines three examples of autopilot systems used for professional and research purposes, including amateur use. The Pixhawk 4 and MP21283X autopilots with different characteristics to redundancy are analyzed, as well as the NASA Swift UAV using off-the-shelf autopilot solutions. The paper offers a detailed analysis of each device’s avionics systems and functionality.

Case #1

The Pixhawk 4 is PX4 autopilot hardware with an open hardware design on the NuttX system, used for commercial, amateur, and professional UAVs. Among the avionics components: ICM-20689 and BMI055 (stabilization gyros), IST8310 (magnetometer), MS5611 (barometer), and u-blox Neo-M8N (GPS receiver) (Holybro, n.d.). The interface includes 8 to 16 servos, 8 of which are from IO and 8 from FMU. The device provides connection of the following peripherals: GPS, power control board, range finders, radio modules, and digital airspeed sensor (Holybro, n.d.). Pixhawk 4 has multiplex control buses, multiplex peripheral buses, and two to three analog inputs for power supplies. Redundancy is by Voting Logic to create a hierarchy between independent critical parts (Sam, 2019; Holybro, n.d.). The Pixhawk 4 should be assigned the first level of autonomy by NASA, as it is an autopilot doing work under supervision (Wang & Liu, 2012).

Table 1

Case #2

The MP2128^3X is autopilot equipment with triple redundancy technology used to transport valuable cargo to increase the reliability of the UAV. The autopilot includes the following avionics systems: (transponders and communication provisioning), AGL (orientation), PID (camera stabilization), accelerometers (orientation), altimeter (orientation), magnetometer (navigation/compass), GPS (navigation). The MP2128^3X has six servos (Micropilot, n.d.). The MP2128^3X supports the connection of the following peripherals, namely PTZ and onboard transponders. Backup parts consist of triplex autopilot and Pass or Fail batteries, diplex radio modems, multiplex (8) high-current drivers, and triplex GPS (Micropilot, n.d.). Regarding NASA autonomy levels, the MP2128^3X is awarded level one because the device uses a program written by the observer and is not capable of self-programming.

Table 2

Case #3

The NASA Swift avionics systems highlight the Athena Guidestar GS111m INS/GPS, responsible for navigation, the Pontech SV203 Servo Controller, radio control, and the Custom Servo Switching Board, a modifiable servo motor (Ippolito, 2012). In addition, the system includes FCS for flight control, CDHS for data processing control, COM communication systems, and SENS flight sensors. Of these subsystems, the CDHS is most similar to an off-the-shelf autopilot in that it includes the Rockwell Collins Athena 111m, which is an autopilot for small UAVs. The Rockwell Collins Athena 111m allows comprehensive evaluation of the UAV’s location and configurable flight characteristics — although, unlike the MP2128^3X, the Rockwell Collins Athena 111m does not have a backup autopilot to improve the reliability of UAV control (Rockwell Collins, 2012). Swift’s automated behavior includes UAV takeoff and landing and autopilot capabilities. According to NASA’s autonomy levels, this UAV is Level 4 because it is capable of complete autonomous control.

Table 3

Conclusion

This paper has examined various approaches to creating autopilot solutions, including UAVs based on off-the-shelf autopilot. The main conclusion is that autopilot systems rapidly evolve, offering competitive advantages for every application. While some autopilots are investing in increasing the comprehensiveness of avionics systems — Pixhawk 4, NASA Swift — others are developing backup control systems to improve control reliability in the event of loss of UAV communications.

References

Holybro. (n.d.). Pixhawk 4 [PDF document]. Web.

Ippolito, C. (2012) An autonomous autopilot control system design for small-scale UAVs [PDF document]. Web.

Micropilot. (n.d.). MP2128^3X triple redundant UAV autopilot [PDF document]. Web.

Rockwell Collins. (2012). Athena 111m [PDF document]. Web.

Sam (2019). What is a redundant system and how do drones use them?DronesVilla. Web.

Schmidt. (2016). UAV propulsion tech post #19 – triple redundant UAV autopilot. UAV PT. Web.

TDK. (n.d.). High performance 6-axis MEMS motion tracking device [PDF document]. Web.

Wang, Y., & Liu, J. (2012). Evaluation methods for the autonomy of unmanned systems. Chinese Science Bulletin, 57(26), 3409-3418. Web.