11种数字滤波函数（国外英文资料）.docVIP

11种数字滤波函数（国外英文资料） The principle and implementation of 11 classical software filtering The limited filter method (also called the procedural judgment filtering method) A, methods: Based on experience, the maximum deviation value (set to A) is determined by two sampling permits. Each time a new value is detected: If this value is not the same as the last value, the value is valid If this value is the difference from the previous value, A, the value is invalid and the value is given up and replaced with the previous value B, advantages: The ability to overcome impulsive interference caused by accidental factors C and disadvantages You cant suppress that kind of periodic interference Poor smoothness Median filter method A, methods: Continuous sample N times N times N odd. Arrange the N sample values by size Take the middle value for this valid value B, advantages: Can overcome the disturbance caused by accidental factors The measured parameters of temperature and liquid level are well filtered C, disadvantages: It is not suitable for fast changing parameters such as flow rate and speed Arithmetic mean filtering method A, methods: The arithmetic mean arithmetic of N sample values is performed consecutively Large N value: high signal smoothness, but low sensitivity N values: low signal smoothness, but high sensitivity N values: general flow, N = 12; Pressure: N = 4 B, advantages: It is suitable for filtering the signal with random interference The signal is characterized by an average signal that moves up and down near a numerical range C, disadvantages: Real-time control that is slow to measure or require fast data is not applicable More waste of RAM Recursive average filtering method (also known as sliding average filtering method) A, methods: You take the N sample values as a queue The length of the queue is fixed to N Every time a new data is taken into the teams tail, the first data is thrown away. The new filtering results can be obtained by averaging the N data in