Digital, self-diagnosis, sensing intelligent layer integrating active and passive monitoring and method

A digital, self-diagnosis, sensing intelligent layer integrating active and passive monitoring, comprising:

• a piezoelectric transducer self-diagnosis module, an active and passive monitoring module, and a main control module, wherein
• the piezoelectric transducer self-diagnosis module comprises:
• a capacitance testing unit, configured to charge a to-be-tested piezoelectric transducer by generating a step signal of a given amplitude, determine a transition moment by comparing a voltage at two terminals of the to-be-tested piezoelectric transducer with a first reference voltage, to determine a capacitor charging time, and then, obtain a free capacitance value of the to-be-tested piezoelectric transducer, to determine whether the free capacitance value is normal;
• and
• a frequency testing unit, configured to charge the to-be-tested piezoelectric transducer by generating sinusoidal signals of different frequencies and a fixed amplitude, determine a changing voltage according to a current of the to-be-tested piezoelectric transducer, compare the changing voltage with a second reference voltage, and detect a resonant frequency according to a frequency of a sinusoidal signal corresponding to a transition moment for high and low levels in a comparison result;
• the active and passive monitoring module is configured to obtain analog response signals from the piezoelectric transducer in an active mode and a passive mode, and convert the analog response signals into digital response signals for transmission;
• and
• the main control module is configured to transmit a piezoelectric transducer self-diagnosis result and the digital response signals to an external guided wave host;
• and
• the digital, self-diagnosis, sensing intelligent layer further comprises N piezoelectric transducers, and a 1-out-of-N excitation selector, a 1-out-of-N acquisition selector, and N switches that are connected to the piezoelectric transducers, to switch to a corresponding channel in different modes, wherein
• in a piezoelectric transducer self-diagnosis mode, the 1-out-of-N excitation selector and the N switches are all opened, and the 1-out-of-N acquisition selector closes a corresponding switch channel according to a serial number of the to-be-tested piezoelectric transducer, to perform a capacitance test and a frequency test on the to-be-tested piezoelectric transducer;
• in the active mode, the N switches are all opened, a corresponding switch channel in the 1-out-of-N excitation selector is closed according to a serial number of an exciting piezoelectric transducer emitting an excitation, and a corresponding switch channel in the 1-out-of-N acquisition selector is closed according to a serial number of a receiving piezoelectric transducer receiving a response, to obtain the analog response signal of the piezoelectric transducer in the active mode and convert the analog response signal into the digital response signal;
• and
• in the passive mode, the 1-out-of-N excitation selector and the 1-out-of-N acquisition selector are both opened, and the N switches are all closed, to obtain the analog response signal of the piezoelectric transducer in the passive mode and convert the analog response signal into the digital response signal.