过采样和非线性校正在中子发生器控制台上的应用

Application of oversampling and nonlinear error correction in neutron generator console

在以往的中子发生器控制台中,由于AD采样精度低、驱动电路电子器件产生温漂、时漂,导致整体采样电路非线性误差大.针对上述问题,提出了使用过采样技术提高AD采集分辨率,同时利用最小二乘法线性回归对采样结果进行非线性校正.使用ARM-Cortex-M4为内核的STM32F407作为主控芯片,使用过采样技术并结合电路特性进行非线性校正,将AD采集分辨率由12位提高到16位,采样数据采用最小二乘法拟合后,结果非线性误差为0.2%,符合中子发生器控制台精度要求.

In the neutron generator console,the real-time working state of the neutron tube can be characterized by the storage current,ion source current,accelerator voltage,current and other electrical parameters.However,in the former neutron generator console,the non-linear error of the whole sampling circuit is large because of the low sampling accuracy of AD and the drift of the driving circuit electronic devices.In order to solve the above problems,the over-sampling technique is proposed to improve the resolution of AD acquisition,and the least square linear regression method is used to correct the non-linearity of the sampling results.In the actual test,STM32F407 with ARM-Cortex-M4 as the core isused as the main control chip.Oversampling technology and circuit characteristics are used to correct the nonlinearity.The resolution of AD acquisition is raised from 12 bits to 16 bits.After fitting the sampling data with least square method,the nonlinearity error is reduced from 1.6%to 0.2%,which meets the accuracy requirements of the neutron generator console.