Scientists at NASA’s Glenn Research Center have developed a circuit board that serves as a control and sampling interface to an inertial measurement unit (IMU). The circuit board provides sampling and communication abilities that allow the IMU to be sampled at precise intervals. The data is minimally processed onboard and returned to a separate processor for inclusion in an overall system. The circuit board allows the normal overhead associated with IMU data collection to be performed outside of the system processor, freeing up time to run intensive algorithms in parallel. This Glenn technology consists of the circuit schematic, board layout, and microcontroller firmware for the IMU sampling and control circuit board.
For fast platform dynamics, it is necessary to sample the IMU at quick intervals in order to fulfill the Nyquist sampling theorem requirements. This can be difficult in cases where low size, weight, and power are required, since a primary processor may already be saturated running the navigation algorithm or other system functions. Glenn’s novel circuit board was designed to handle the sampling process (involving frequent interrupt requests) in parallel, while delivering the resulting data to a buffered communication port for inclusion in the navigation algorithm on an as-available basis. The circuit operates using a universal serial bus (USB) or Bluetooth interface. A control command is sent to the circuit from a separate processor or computer that instructs the circuit how to sample data. Then, a one-pulse-per-second signal is sent to trigger the circuit to perform automatic data collection from the IMU sensor.
Various navigation sensors can be synchronized very closely in time. In addition, the board does not require maintenance unless a component is damaged. This is an early-stage technology requiring additional development. Glenn welcomes co-development opportunities.
Potential applications include navigation, robotics, process control and industrial automation, and instrumentation and measurement.