Biscarini Andrea
Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy.
Biomimetics (Basel). 2021 Feb 10;6(1):14. doi: 10.3390/biomimetics6010014.
The values of a physiological parameter and its time derivatives, detected at different times by different sensory receptors, are processed by the sensorimotor system to predict the time evolution of the parameter and convey appropriate control commands acting with minimum latency (few milliseconds) from the sensory stimulus. We have derived a power-series expansion (U-expansion) to simulate the fast prediction strategy of the sensorimotor system. Given a time-function , a time-instant , and a time-increment , the U-expansion enables the calculation of from and the values of the derivatives of at arbitrarily different times , instead of time as in the Taylor series. For increments significantly greater than the maximum among the differences , the error associated with truncation of the U-expansion at a given order closely equalizes the error of the corresponding Taylor series () truncated at the same order. Small values of and higher values of correspond to the high-frequency discharge of sensory neurons and the need for longer-term prediction, respectively. Taking inspiration from the sensorimotor system, the U-expansion can potentially provide an analytical background for the development of algorithms designed for the fast and accurate feedback control of nonlinear systems.
由不同感觉感受器在不同时间检测到的生理参数及其时间导数的值,由感觉运动系统进行处理,以预测该参数的时间演变,并从感觉刺激开始以最小延迟(几毫秒)传递适当的控制指令。我们推导了一个幂级数展开式(U展开式)来模拟感觉运动系统的快速预测策略。给定一个时间函数、一个时刻和一个时间增量,U展开式能够根据和在任意不同时刻的导数的值来计算,而不是像泰勒级数那样根据时间来计算。对于明显大于差值中的最大值的增量,在给定阶数下截断U展开式所产生的误差与在相同阶数下截断相应泰勒级数()所产生的误差非常接近。较小的值和较高的值分别对应于感觉神经元的高频放电和长期预测的需要。受感觉运动系统的启发,U展开式有可能为开发用于非线性系统快速准确反馈控制的算法提供一个分析背景。