• 전자공학회논문지
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• 제54권6호
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• pp.93-99
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• 2017

본 연구에서는 Xilinx의 Zynq SoC (system on chip)를 이용하여 초음파 신호의 TOF (Time of Flight)를 측정한다. TOF는 특정 거리를 이동하는 데 소요되는 RF (radio frequency) 기준 신호와 초음파 신호의 시간차이로 부터 계산되고, 공기중 초음파의 속도를 곱하여 초음파 이동거리를 알아낸다. 이를 위해 Zynq의 내장 ADC, FIR (finite impulse response) 필터, Kalman 필터로부터 초음파 펄스를 생성하고, RF 인터페이스로부터 RF 기준펄스를 생성한다. Kalman 필터와 RF 인터페이스는 baremetal 멀티프로세싱에 의해 Zynq의 듀얼 프로세서 코어에 c-코드로 프로그래밍하고 나머지 구성 요소들은 Zynq의 FPGA 내에 설계하여, HW/SW co-design을 구현한다. 이를 통해 HW design에 비해 Zynq 자원의 가용률을 낮추고, 설계 시간을 대폭 줄일 수 있었다. 설계 툴로 Vivado IDE (integrated design environment)를 이용하여, 전체 신호처리 시스템을 계층적 블록 다이어그램의 형태로 설계하였다.

• 전기학회논문지
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• 제66권8호
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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.