Abstract:
A robotic ultrasonic inspection vehicle is provided with one or more transducers which are driven by a long, broadband excitation pulse for insonifying a sample subject to inspection. The long, broadband excitation pulse can be chirped. The robotic vehicle also can include a drive circuit for coupling the excitation pulse to the transducer. Data associated with the excitation pulse is used to gate off the drive circuitry at an appropriate time. The robotic vehicle may traverse a combustion prone region and therefore electrical parameters may be limited to intrinsically safe levels. However electrical parameters may safely be converted to higher levels so long as the conversion is inhibited to occur only after the vehicle has left a combustion prone region and entered a region of minimal risk of combustion.
Abstract:
The present invention is directed to a high-powered (e.g., >500 W) ultrasonic generator for use especially for delivering high-power ultrasonic energy to a varying load including compressible fluids. The generator includes a variable frequency triangular waveform generator coupled with pulse width modulators. The output from the pulse width modulator is coupled with the gates of an Isolated Gate Bipolar Transistor (IGBT), which amplifies the signal and delivers it to a coil that is used to drive a magnetostrictive transducer. In one embodiment, high voltage of 0-600 VDC is delivered across the collector and emitter of the IGBT after the signal is delivered. The output of the IGBT is a square waveform with a voltage of +/−600V. This voltage is sent to a coil wound around the ultrasonic transducer. The voltage creates a magnetic field on the transducer and the magnetorestrictive properties of the transducer cause the transducer to vibrate as a result of the magnetic field. The use of the IGBT as the amplifying device obviates the need for a Silicon Controlled Rectifier (SCR) circuit, which is typically used in low powered ultrasonic transducers, and which would get overheated and fail in such a high-powered and load-varying application.
Abstract:
A portable electronic device (100) includes a vibrating transducer having a resilient support and a first mass supported by the first resilient support forming a mechanical resonator, and an electrical circuit coupled to the first vibrating transducer to apply a drive signal. A plurality of tactile vibration transducers (130, 140) can work in unison to produce strong tactile stimulus (216, 228, 230).
Abstract:
The present invention is directed to a high-powered (e.g., >500 W) ultrasonic generator for use especially for delivering high-power ultrasonic energy to a varying load including compressible fluids. The generator includes a variable frequency triangular waveform generator coupled with pulse width modulators. The output from the pulse width modulator is coupled with the gates of an Isolated Gate Bipolar Transistor (IGBT), which amplifies the signal and delivers it to a coil that is used to drive a magnetostrictive transducer. In one embodiment, high voltage of 0-600 VDC is delivered across the collector and emitter of the IGBT after the signal is delivered. The output of the IGBT is a square waveform with a voltage of ±600V. This voltage is sent to a coil wound around the ultrasonic transducer. The voltage creates a magnetic field on the transducer and the magnetorestrictive properties of the transducer cause the transducer to vibrate as a result of the magnetic field. The use of the IGBT as the amplifying device obviates the need for a Silicon Controlled Rectifier (SCR) circuit, which is typically used in low powered ultrasonic transducers, and which would get overheated and fail in such a high-powered and load-varying application.
Abstract:
A robotic ultrasonic inspection vehicle is provided with one or more transducers which are driven by a long, broad-band excitation pulse for insonifying a sample subject to inspection. Preferably the long, broadband excitation pulse is chirped. The robotic vehicle also includes a drive circuit for coupling the excitation pulse to the transducer. Data associated with the excitation pulse is used to gate off the drive circuitry at an appropriate time. The robotic vehicle may traverse a combustion prone region and therefore electrical parameters may be limited to intrinsically safe levels. However electrical parameters may safely be converted to higher levels so long as the conversion is inhibited to occur only after the vehicle has left a combustion prone region and entered a region of minimal risk of combustion.
Abstract:
A screening machine that includes a screen having a periphery and a central porous region is provided. A motion amplifier is substantially rigidly attached in direct contact with the periphery of the screen and not in direct contact with the central porous region. A transducer is substantially rigidly attached to the motion amplifier, wherein the transducer imparts a vibratory motion to the screen via the motion amplifier.
Abstract:
A screening machine having a base is provided. A screen is coupled to the base to separate material by size. The screening machine includes a vibration motor having piezoelectric elements and a vibration amplifier located between the piezoelectric elements and the screen. One or more of the piezoelectric elements can be used as sensors to provide feedback for operation control.
Abstract:
The invention utilizes a multiple frequency ultrasound generator driving a multiple frequency harmonic transducer array to improve cleaning and processing effects while eliminating damage to parts being cleaned. An AC switch and circuitry to modify the output of an ultrasound generator in combination with techniques such as random AM and FM signals are used to produce ultrasound waves that have no single frequency components which eliminates exciting parts being cleaned into resonance. Generator signals that increase cavitation efficiency and that have successive time periods with predominately stable cavitation and predominantly transient cavitation further improve the performance of the cleaning or processing systems.
Abstract:
The invention utilizes a multiple frequency ultrasound generator driving a multiple frequency harmonic transducer array to improve cleaning and processing effects while eliminating damage to parts being cleaned. An AC switch and circuitry to modify the output of an ultrasound generator in combination with techniques such as random AM and FM signals are used to produce ultrasound waves that have no single frequency components which eliminates exciting parts being cleaned into resonance.
Abstract:
Method, apparatus and computer programs are described for compensating for the effect of temperature on the sensitivity of electrostatic ultrasound (US) transducers, particularly as used in an automotive occupancy sensing (AOS) systems for sensing the nature or type of occupant and the location of the occupant with respect to the vehicle interior. The invention permits the AOS to classify the occupancy state of the vehicle from a US echo signal substantially free of the effects of temperature on signal amplitude. A capacitive divider or voltage monitor is employed to measure the capacitance of the transducer. The voltage monitor output is used by the scaling algorithm of a compensator to determine the scaling factor to be applied to the US transducer signal to compensate for the effect of temperature on the transducer sensitivity. Calibration procedures and software are disclosed for determining the coefficients of the scaling algorithm to compensate for temperature effects and also to compensate for installation factors, transducer manufacturing variations, and circuit board effects. The system disclosed is useful for other types of signal processing in addition to temperature compensation of AOS ultrasonic signals, and may be used in other ranging devices such as cameras, golf or binocular range finders, and measuring devices and instruments.