Resonance seeking control

Model-based resonance tracking of linear systems

“…Precise tracking of the resonance frequency of oscillating systems is of great interest in resonant sensing [1,2] and when driving vibrating loads [3,4]. Resonant sensors, the function of which relies on the resonant characteristic of a vibrating structure, have been proposed for a wide range of measurements like thermometers [5], accelerometers [6], viscometers [7], humidity [8], water cut measurement [9] and gyroscopes [10,11] to mention a few.…”

“…Even in case of actuators that have been designed to operate at a constant resonance, shifts from the designed operating frequency may occur because of environmental changes, like temperature and humidity [20], aging of the device [21] or changes in the load [18,15]. As a remedy, designers resort to feedback resonance tracking control to compensate for these shifts and achieve maximum efficiency [4,13]. In the case of sensing applications based on changes of the resonance frequency with the measured quantity, the use of the feedback control is unavoidable and the performance of the control system directly affects the sensitivity, resolution and the bandwidth of the sensor [21,22].…”

“…In the absence of phase information, a maximum output signal amplitude detection algorithm has been applied in piezoresponse force microscopy [29]. A maximum power tracking adaptive approach for driving resonant loads has been proposed in [4]; a small sinusoidal perturbation signal is added to driving signal in order to estimate the derivative of the absorbed power and update the excitation frequency. A control algorithm that tunes the system to a specific resonance frequency has been developed to address the issue of on-line modal frequency matching in vibratory gyroscopes [25].…”