| 摘要 |
PROBLEM TO BE SOLVED: To reduce the amplitude of the noise component of a high frequency without the occurrence of delay by changing the largeness of output upper limit width and lower limit width in accordance with the largeness of an output signal for the portion of secular change. SOLUTION: A signal processing part 1 is constituted of an upper/lower limit restricting part 11, a moving average arithmetic part 12, an inclination arithmetic part 13, an upper/lower limit width arithmetic part 14 and an upper/lower limit value arithmetic part 15. An output upper limit value is obtained based on the secular change rate of an average value within the past prescribed time section of the output signal. When the value of an input signal is equal to below the output upper limit value, a value corresponding to the input signal is adopted as the output signal. When the value of the input signal is larger than the output upper limit value, the value corresponding to the output upper limit value is adopted as the output signal. An output lower limit value is obtained based on the secular change of the average value within the past prescribed time section of the output signal. When the value of the input signal is equal to below the output lower limit value, the value corresponding to the input signal is adopted as the output signal. When the value of the input signal is smaller than the output lower limit value, the value corresponding to the output lower limit value is adopted as the output signal. |
