Non-stationary signals, such as the autocorrelation function (ACF), can be considered stationary when the variation of the function with time is slow. However, the fluctuation of the ACF of high-frequency signals is a very slow process, and thus, it is not a stationary function. Hence, the ACF values of the low-frequency and high-frequency components of non-stationary signals should be averaged.
The output of the integral circuit is called the zero-crossing point (ZCP) signal, which is the time when the phase change is 180°. The integral circuit is the most important component in the evolution of the development of the electric braking system and it is designed for the exact detection of the instantaneous voltage value at each ZCP. Two kinds of detectors are used to detect the ZCP; one of them is the zero-crossing detector and the other one is the zero-crossing amplitude detector. There is no difference between the corresponding circuit diagrams of both detectors, although one of them uses an amplifier and the other one uses a comparator. Both control their signals with the same reference voltage. However, the zero-crossing amplitude detector is preferred because of its lower complexity. It is because it does not use an amplifier, there is only the need to connect the input of the integrator to the connection point between the ground and the reference voltage.
The bandwidth of the system is determined by the bandwidth of the RC filter, while it is affected by the amount of time for the signal to reach the ZCP. Therefore, the higher the order of the RC filter, the higher the DC gain, and the higher the bandwidth of the detector.
A voltage converter is used to measure a voltage signal that is converted into a current signal. It is an essential part in the measurement system because it can generate an accurate voltage signal from the measured current signal. The transconductance of the current to voltage converter is proportional to the current to which the output is connected, and therefore, it is possible to, by determining the appropriate current, minimize its effect on the output signal. Hence, the output current of the current to voltage converter provides the load resistance for the measuring circuit. d2c66b5586