| With the development of embedded systems,more and more researchers have implemented the Support Vector Machine(SVM)based algorithm using embedded systems for portable and wearable applications.However,one challenge is that embedded system has critical restrictions in hardware resources,storage capacity and energy efficiency.Therefore,how to optimize the hardware resource consumption and energy efficiency becomes the main difficulty and challenge.SVM algorithm includes two processes,namely training and inference.In this thesis,we focused on the hardware implementation of SVM inference model.First,we implemented an SVM based inference platform based on FPGA.The system architecture of the platform is presented firstly.The SPI and synchronizer module in the platform are designed to implement the data communication between the platform and the peripheral system(e.g.,CPU).Then the design of each module in the platform is elaborated,respectively.In order to reduce resource and power consumption,data precision representations were optimized and a strategy of variable precision exponential function calculation was proposed in SVM inference function module.Using the NexysVedio evaluation board with a Xilinx Artix7 FPGA chip,a prototype of the SVM inference platform was implemented and the system performance was evaluated.Compared to the design without the optimizations mentioned before,the platform can reduce 13% power and 50% energy per test vector calculation,with only a little impact on the final calculation accuracy.We also implemented a system for SVM-based blood pressure prediction based on Digital Signal Processor(DSP),including feature extraction and SVM inference model.Two features are extracted firstly from photoplethysmography(PPG)signal.Based on the input features,the SVM inference function,which is implemented using floating-point algorithmic routines,can perform blood pressure prediction accordingly.We tested 5 volunteers using our proposed system,the MAEs(Mean Absolute Error)±STD(Standard Derivation)of predicting error for systolic blood pressure(SBP)and diastolic blood pressure(DBP)are 8.42±10.30 mmHg and 6.03±7.64 mmHg,respectively. |
