Guo, Q.Deng, W. H.Bebek, ÖzkanCavusoglu, M. C.Mastrangelo, C. H.Young, D. J.2019-02-122019-02-122018-110018-9200http://hdl.handle.net/10679/6169https://doi.org/10.1109/JSSC.2018.2868263A personal inertial navigation system (PINS) assisted by a microelectromechanical systems (MEMS)-based 13 × 26 ground reaction sensor array (GRSA) and a low-power interface application-specified integrated circuit (ASIC) has been designed and demonstrated for GPS-denied environment. The GRSA operating in a contact mode achieves a sensitivity of approximately 3.7 fF/kPa at each sensor node. An electronic interface system, consisting of a capacitance-to-voltage (C/V) converter followed by a correlated double sampling stage, is designed to convert the GRSA capacitance change to an analog output voltage. The analog output voltage is then digitized by a 12-bit cyclic analog-to-digital converter (ADC). Switch capacitance compensation technique is employed to ensure the ADC performance. The ASIC is fabricated in 0.35-μm CMOS process and dissipates a power of 3 mW. The prototype system incorporates a GRSA, an ASIC, and a commercial nine degreeof-freedom (DOF) inertial measurement unit (IMU) in the heel region of a boot. The GRSA can determine an accurate foot-onground timing based on the pressure profiles detected during walking, thus enabling an accurate position calculation and a precise zero velocity update. Furthermore, a system calibration procedure measures the IMU inherent directional drift and scaling factor errors, and compensates them for the navigation data to achieve a superior performance. The prototype system demonstrates a position accuracy of approximately 5.5 m over a navigation distance of 3100 m. The prototype system also achieves a consistent performance over different field tests with various distances and random paths. System characterization results further indicate a tradeoff between sensor array size and system resolution for a given navigation performance requirement, thus providing a design guideline for future system optimization.engrestrictedAccessarticle53113039304900044910840000410.1109/JSSC.2018.2868263Capacitance-to-voltage (C/V) converterCapacitive sensorCyclic analog-to-digital converterGPS-denied navigationGround reaction sensor array (GRSA)Inertial measurement unit (IMU)Personal inertial navigation system (PINS)Pressure sensor arraySwitch capacitance compensationTactile sensor array2-s2.0-85054493368