Inertial Solutions
Nelson Henderson
Daniel Island, SC


Inertial Solutions is closed. This site displays the history of Design & Development work by Nelson Henderson.  Portions of his work are placed in the public domain (subject to restrictions of US law).  The Products allowed:
  • Augmented Navigation with GPS
  • Control Attitude
  • Control Heading & Direction
  • Sense and control level
  • Sense Barometric Altitude
  • Sense Airspeed
  • Sense Ground speed & Direction

  • Land and Off-Road Vehicles
  • Unmanned Aerial Vehicles
  • Antenna Pointing
  • Platform Stabilization
  • Automotive Test
  • Marine Vessels

Inertial Products:

A dozen (12) unsold complete systems remain ($2,200 each including a copy of the source code and compiler).  Recommend instead, the 3DRobotics Pixhawk autopilot.  Although, the one unsurpassed feature of the Inertial Solutions product is the 16 channel Time Processing Unit (TPU) on the MC68332 CPU.  The TPU allows the software to synchronize accurately to the GPS Time Mark strobe which generates a precisely timed interrupt on one of the TPU channels.

Typically, a user's navigation computer reads the stream of attitude, heading, and position messages coming from the Inertial Solutions processor card in order to compute and to provide back to the controller, command messages for steering, throttle, etc..

However, most features and more are available on the Pixhawk from 3DRobotics at a better price.  3DRobotics sponsors an open source community project doing more advanced development.  The software does more, the hardware is miniturized, and the processor is more powerful.  Mr Henderson of Inertial Solutions is contributing to the open source project.

 Solutions page shows The Inertial Solutions Flight Control User Interface that is similar to "Mission Planner" software freely downloaded to control the 3DRobotics Pixhawk autopilot.

Inertial Solutions:

The new 3DRobotics Pixhawk with the 168 MHz ARM STM32F429 with single precision floating point coprocessor, solves the computational limitations of the former Inertial Solutions 16 MHz MC68332 CPU.

The origonal goal of a hands off take-off to landing flight will soon be accomplished using the Pixhawk. This site records progress seen at its beginning in these old photographs:

  1. Blue-Bird model with twin Veco .61 engines.
  2. Author, designer, builder, & RC Pilot at Vandenberg AFB CA.
  3. Air Weather Service tracking airborne Rawinsonde.


  1. Completed:  Refurbish Blue-Bird 18.5 lb, 9' wingspan twin engine radio-control model. Convert to Electric power.
  2. Completed:  Install the airplane auto-pilot, telemetry link, flight control center.
  3. Completed:  Retrain RC flying skills on the Phoenix Flight Simulator.
  4. Completed:  Test fly the Radio-control model on electric power using Arduino instruments to collect in-flight data, sending it down for display on Mission Planner.
  5. Perform flight test, post flight analysis of thrust-lift-drag profiles, stall speed, PID controller tuning.
  6. Perform hands-off, take-off to landing flight.
  7. Sell the airplane, seen on this site, along with new autopilot (installed in airplane), Ground Control Center (Notebook PC with RF link), and Radio Control (8 channel CDMA 2.4 GHz).  Mission accomplished. ($7K)