MP2128HELI2 flight-control computer

The MP2128HELI2 is a flight-control computer from MicroPilot, a Canadian autopilot manufacturer that has designed autopilots for fixed-wing, transitioning, multirotor and helicopter unmanned aircraft since 1994. It is the helicopter version of the MP2128 circuit-board autopilot family, and it serves as the onboard flight controller for unmanned helicopters and other rotary-wing vehicles, with multirotor operation also supported across the MP2128 line.

The MP2128HELI2 is the helicopter counterpart of the MP2128g2 fixed-wing autopilot, and the two share the same improvements over the earlier MP2128g. Processing throughput is three times that of the earlier board. The control-loop update rate reaches 180 Hz, compared with 90 Hz before, which matters for helicopters and multirotors because a faster inner loop gives tighter attitude control and better response to disturbances. The board has 16 MB of RAM and 8 MB of flash storage, allowing larger customer plug-ins and larger, higher-frequency datalogs.

Sensing and navigation are built into the board. The maker describes improved accelerometers and rate gyros for a better attitude estimate, and an integrated 4 Hz single-chip GPS receiver that reduces the board weight by 15% to 24 grams. When higher positional precision is needed, an external Novatel carrier-phase GPS can be used instead. The autopilot supports a command buffer of 1,000 waypoints and allows the operator to upload waypoints, insert, delete and move them, and send the aircraft to a chosen waypoint or position while it is in flight.

For integration, the board is upward compatible with the earlier MicroPilot autopilots in form factor, connectors and configuration settings, which allows an existing airframe design to adopt it without redesigning the installation. Spread-spectrum clocks and an improved board layout reduce both the interference the board receives and the interference it emits, which helps when it is installed beside radios and payload electronics. A secondary microcontroller provides a dead man safety function, and the board is built to IPC Class 3 standards. In the triple-redundant MP2128 3X, three MP2128HELI2 autopilots are combined with eleven serial ports, eight high-current drivers and sixteen servo outputs.

The autopilot is used for fully autonomous operation from launch through recovery, with ground control and mission planning through MicroPilot's HORIZON mp software. Typical applications are unmanned helicopter surveillance, payload delivery and survey missions, and development platforms for rotary-wing vehicles that require a certified-class flight computer with a long product history.