• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.6
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• pp.93-99
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• 2017

In this research the TOF (time of flight) of ultrasonic signal is measured using Xilinx's Zynq SoC (system on chip). The TOF is calculated from the difference between periods during which RF (radio frequency) and ultrasonic signals come across a distance, and then travelling distance is obtained by multiplying the TOF by the ultrasonic speed in the air. For this purpose, a ultrasonic pulse is generated from a Zynq's internal ADC, a FIR (finite impulse response) filter, and a Kalman filter. And a RF reference pulse is generated from a RF interface. Based on baremetal multiprocessing, the Kalman filter and the RF interface are c-programmed on Zynq's dual processor cores, with other components fabricated on Zynq's FPGA. With this HW/SW co-design, both lower resource utilization and much smaller designing period were obtained than the HW design. As a design tool, Vivado IDE(integrated design environment) is used to design the whole signal processing system in hierarchical block diagrams.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.8
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• pp.1250-1256
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• 2017

In this research, a high-performance ultrasonic positioning system is proposed to track the positions of an indoor mobile object. Composed of an ultrasonic sender (mobile object) and a receiver (anchor), the system employs three ultrasonic time-off-flights (TOFs) and trilateration to estimate the positions of the object with an accuracy of sub-centimeter. On the other hand, because ultrasonic waves are interfered by temperature, wind and various obstacles obstructing the propagation while propagating in air, ultrasonic pulse debounce technique and Kalman filter were applied to TOF and position calculation, respectively, to compensate for the interference and to obtain more accurate moving object position. To perform tasks in real time, ultrasonic signals are processed full-digitally with a Zynq SoC, and as a software design tool, Vivado IDE(integrated design environment) is used to design the whole signal processing system in hierarchical block diagrams. And, a hardware/software co-design is implemented, where the digital circuit portion is designed in the Zynq's fpga and the software portion is c-coded in the Zynq's processors by using the baremetal multiprocessing scheme in which the c-codes are distributed to dual-core processors, cpu0 and cpu1. To verify the usefulness of the proposed system, experiments were performed and the results were analyzed, and it was confirmed that the moving object could be tracked with accuracy of sub-cm.