Proportional-integral-derivative controller is the classical control strategy. In this blog, I use python to write a primitive PID controller. PID Control import time import matplotlib.pyplot as plt from scipy.interpolate import make_interp_spline import numpy as np class PID: def __init__(self, P=0.2, I=0.0, D=0.0, current_time=None): self.Kp = P self.Ki = I self.Kd = D self.current_time = current_time if current_time is not None else time.time() self.last_time = self.current_time self.ControlPoint = 0.0 self.last_error = 0.

Definite matrix Figure 1: Definitions for real matrices Definition Positive-definite matrix In mathematics, a symmetric matrix M with real entries is positive-definite if the real number \(z^TMz\)is positive for every nonzero real column vector \(z\), A Hermitian matrix(a complex matrix equal to its conjugate transpose is positive-definite if the real number \(z^{*}Mz\) is positive Positive semi-definite Defined similarly, except that \(z^TMz\) and \(z^{*}Mz\) are required to be positive or zero. Negative-definite and negative semi-definite matrices are defined are defined analogously.