These solutions are mainly based on correcting the delays between the signals coming from loudspeaker system transducers, and they still show limited performances over the overlap frequency bands.
In order to correct the frequency response or the lobbing errors of a multiway loudspeaker system, most solutions [1, 4] are based on delaying the signals sent to the loudspeaker system transducers.
Various smart materials such as shape-memory alloys (SMAs) [4], polyvinylidene fluoride (PVDF) films [5, 6, 7], piezoelectric polymer actuators [8], macrofiber composites [9, 10], and microelectromechanical system transducers [11] have been used to control the surface shape of membrane structures.
The sensitivity of the whole system (transducers, chart recorder, and PC software) was 0.34 kPa.
The peripheral device consisted of a goniometry compass and an interface system-transducer cooperated with the computer.
The system (Smart Transducer Interface Module, STIM) features a simplified Transducer Independent Interface TIII) based on a 3-wire RS232 asynchronous communication and is conceived as a cluster between identical monosensor subsystems and a central Controller.
In order to test the swelling behavior of montmorillonite, shale expansion instrument is mainly utilized for analysis (Zhao et al. 1996), and the shale expansion instrument contains four parts which are mechanical measuring system, displacement transducer, measuring instrument, data processing and storage device (Li and Li 1995).
All CUS scans were performed by trained and certified sonographers using high-resolution imaging systems with linear array transducers operating at a fundamental frequency of at least 7.5 MHz (for each subject, the same ultrasound imaging system and transducer were used throughout the study).
In gas-filled systems, the transducer diaphragm movement can prove to be a significant contributor to the system response and its effect is more pronounced when measuring small fluctuations in high-pressure systems.
An experimental project is presented to demonstrate the capability of embedded systems in transducer design.
The result of modelling all the layers in the system, including transducers, fluid and substrate, is shown in Figure 3 by the red line.
