论文部分内容阅读
为了保证高精度光电轴角编码器在恶劣工作条件下的细分精度,设计了基于高分辨率数字电位计的实时补偿处理系统。依据莫尔条纹光电信号的数学模型,说明了由信号等幅性偏差和直流电平漂移引起的细分误差的空间分布特征,并得出误差规律及计算公式,从编码器的光机装调、码盘均匀性、光敏元件调试等制作环节出发,指出了编码器光电信号细分误差的根本特性;受高精度光电编码器分辨力的约束,从编码器光敏元件输出莫尔条纹信号的形式出发,构建了分辨率为0.1Ω的数字电位计查找表;并设计了实时补偿的关键算法。以23位光电编码器为实验对象,在-40~60℃条件下对补偿处理系统测试,实验结果表明:直流漂移≤1.2%,等幅性≤2%,且自动补偿时间约为3 s,满足编码器分辨力(0.154″)和工作实时性的要求。该方法可实际应用于编码器系统,能够提高编码器的环境适应性和测角可靠性。
In order to ensure the precision of photoelectric encoder in high precision, the real-time compensation processing system based on high-resolution digital potentiometer is designed. According to the mathematical model of moiré fringe photoelectric signal, the spatial distribution characteristics of subdivision error caused by the equal amplitude deviation and the dc level drift of the signal are described. The error law and calculation formula are obtained. Encoder uniformity, light-sensitive components debugging and other production starting point, pointed out the basic characteristics of encoder optical signal subdivision error; by the resolution of high-precision optical encoder constraints, the encoder photosensitive element output Moiré fringe signal form , Built a digital potentiometer look-up table with a resolution of 0.1Ω, and designed the key algorithm of real-time compensation. Taking 23 optical encoder as experimental object, the compensation processing system was tested under the condition of -40 ~ 60 ℃. The experimental results show that DC drift is less than or equal to 1.2%, equal amplitude is less than or equal to 2% and automatic compensation time is about 3 s, Which meets the requirements of encoder resolution (0.154 ") and real-time performance.This method can be applied to the encoder system, which can improve the environment adaptability and angle measurement reliability of the encoder.