Foot-mounted INS for everybody - an open-source embedded implementation

Abstract

Abstract-We present an open-source, realtime, embedded implementation of a foot-mounted, zero-velocity-update-aided inertial navigation system. The implementation includes both hardware design and software, uses off-the-shelf components and assembly methods, and features a standard USB interface. The software is written in C and can easily be modified to run user implemented algorithms. The hardware design and the software are released under permissive open-source licenses and production files, source code, documentation, and further resources are available at www.openshoe.org. The reproduction cost for a single unit is below $800, with the inertial measurement unit making up the bulk ($700). The form factor of the implementation is small enough for it to be integrated in the sole of a shoe. A performance evaluation of the system shows a position errors for short trajectories (<100 [m]) of ± 0.2-1 % of the traveled distance, depending on the shape of trajectory.

Accurate indoor positioning of firefighters using dual foot-mounted inertial sensors and inter-agent ranging

“…Each firefighter is equipped with a zero-velocity aided INS [19,24], where tri-axial accelerometer and gyroscope sensors are integrated into the heel of custom-made shoes. Although some of the sensor bias errors for foot-mounted INS can be estimated using zero-velocity updates [25] when the foot is at stand-still, the position and heading error of a foot-mounted INS remains unobservable, and grows (slowly) without bound [4].…”

“…A real-time cooperative localization system, utilizing dual foot-mounted low-cost inertial sensors [19] and inter-agent ranging, has been presented in [4,20]. Considering typical deployments and methodology it is conceivable that shortrange ranging transceivers, e.g., based on ultra-wideband (UWB) transceivers, and cooperative localization techniques could be applied in firefighter operations.…”

Voice radio communication, pedestrian localization, and the tactical use of 3D audio

“…The foot-mounted inertial navigation has been implemented with OpenShoe units on both feet [16]. The OpenShoe units perform the basic step-wise inertial navigation, and supply displacement and heading changes.…”

Dual MIMU Pedestrian Navigation by Inequality Constraint Kalman Filtering

“…An effective technique to bound the error growth is using Zero Velocity Update (ZUPT) [5]. The foot-mounted ZUPT-aided INS was provided as an open source in Openshoe project [6].…”