Other

Klippel Gmbh

Jbl, Incorporated

Wolfgang J Klippel

Ulf Seidel

Daniel Knobloch

Marian Liebig

An arrangement and method for converting an input signal into a mechanical or acoustical output signal by using a transducer and additional means for generating a desired transfer behavior and for protecting said transducer against overload. Transducers of this kind are for example loudspeaker, headphones and other mechanical or acoustical actuators. The additional means comprise a controller, a power amplifier and a detector. The detector identifies parameters of the transducer model if the stimulus provides sufficient excitation of the transducer. The detector permanently identifies time variant properties of the transducer for any stimulus supplied to the transducer. The controller provided with this information generates a desired linear or nonlinear transfer behavior; in particular electric control linearizes, stabilizes and protects the transducer against electric, thermal and mechanical overload at high amplitudes of the input signal.

Method and arrangement for controlling an electro-acoustical transducer

The invention relates to an arrangement and a method for converting an input signal v into an output signal p(r) by using an electro-mechanical transducer and for reducing nonlinear total distortion pin said output signal p(r), whereas the nonlinear total distortion pcontains multi-modal distortion uwhich are generated by nonlinear partial vibration of mechanical transducer components. An identification system generates distributed parameters Pof a nonlinear wave model (N) and lumped parameters Pof a network model (N) based on electrical, mechanical or acoustical state variables of transducer measured by a sensor. The nonlinear wave model distinguishes between activation modes and transfer modes, whereas the activation modes affect the transfer modes, which transfer the input signal u into the output signal p. A control system synthesizes based on the physical modeling and identified parameters Pand Pnonlinear distortion signals vand vwhich are supplied with the input signal v to the transducer and compensate for the distortion signals uand ugenerated by the transducer nonlinearities.

Arrangement and method for identifying and compensating nonlinear vibration in an electro-mechanical transducer

The invention provides an arrangement and a method for measuring the direct sound wradiated by an acoustical source under test (e.g. loudspeakers) under the influence of acoustic ambient noise sources Qand reflections at acoustical boundaries (e.g. room walls). An acquisition device measures a state variable p(r) of the sound field at a plurality of measurement points rin a scanning range Gby a sensor and generates a scanned data set p. Based on this data set an analyzer determines the coefficients Cassociated with expansion functions which are solutions of the wave equation. An identifier uses the scanned data set pfor generating parameter information P for the analyzer which are the basis for separating the direct sound wfrom room reflections wand other waves wscattered at the surface of the source under test. An extrapolator predicts the state variable pof the direct sound wat any point outside the scanning range Gby using the coefficients Cof the wave expansion.

Arrangement and method for measuring the direct sound radiated by acoustical sources

An arrangement and method for converting an input signal z(t) into a mechanical or acoustical output signal p(t) comprising an electro-magnetic transducer using a coil at a fixed position and a moving armature, a sensor, a parameter measurement device and a controller. The parameter measurement device identifies parameter information P of an nonlinear model of the transducer considering and the saturation and the geometry of the magnetic elements. A diagnostic system reveals the physical causes of signal distortion and generates information for optimizing the design and manufacturing process of this transducer. The controller compensates for nonlinear signal distortion, stabilizes the rest position of the armature and protects the transducer against mechanical and thermal overload.

Arrangement and method for converting an input signal into an output signal and for generating a predefined transfer behavior between said input signal and said output signal

The invention relates to an arrangement and a method for the identification of parameters in a nonlinear model of an analog-to-digital converter (ADC) and the use of this information to reduce the nonlinear distortions of the ADC. A parameter estimator determines an AD parameter vector Pwhich describes the nonlinearities of the ADC (). According to the invention the ADC is excited by a perturbed input signal y'generated by adderwhich combines the analog input signal ywith perturbation signal sprovided by generator. The nonlinear system identification uses intermodulation distortion generated in the digital ADC output signal y&#x2032;which are not found in the analog input signal y. A nonlinear AD compensation element compensates based on parameter vector Pthe nonlinear distortion generated by the ADC and generates the linearized output signal y. Digital control information Pare used to generate the perturbation signal sin generator and to remove the perturbation signal the compensation element. The linearized ADC (is the basis for linearizing digital-analog-converters (DAC), amplifiers and other hardware components.

Converter arrangement and method for converting an analogue input signal into a digital output signal

An arrangement and method for assessing the audibility and annoyance of at least one distortion component d(t) with n=1, . . . , N in the output signal p(t) of a device under test, by generating a virtual auralization output signal p(t) at the output of an auralization system. The output signal p(t) contains the distortion component d(t) at an adjustable magnitude according to a scaling factor Sprovided from a control input, and is supplied to a perceptive model and to a reproduction system used by a listener. The auralization system receives the distortion component d(t) from a separator which receives a test signal x(t) from the output of a microphone and a reference signal x(t) from a reference system.

Method and arrangement for auralizing and assessing signal distortion

An arrangement and method for assessing and diagnosing the operating state of a device under test in the presence of a disturbing ambient noise and for detecting, localizing and classifying defects of the device which affect its operational reliability and quality. At least two sensors monitor signals at arbitrary locations which are affected by signals emitted by defects and by ambient noise sources. A source analyzer receives the monitored signals, identifies the number and location of the sources, separates defect and noise sources, and analyzes the deterministic and stochastic signal components emitted by each source. Defect and noise vectors at the outputs of the source analyzer are supplied to a defect classificator which detects invalid parts of the measurements corrupted by ambient noise, accumulates the valid parts, assesses the quality of the system under test and identifies the physical causes and location of the defects.

Method and arrangement for detecting, localizing and classifying defects of a device under test

The invention relates to an arrangement and method for estimating the linear and nonlinear parameters of a modeldescribing a transducerwhich converts input signals x(t) into output signals y(t) (e.g., electrical, mechanical or acoustical signals). Transducers of this kind are primarily actuators (loudspeakers) and sensors (microphones), but also electrical systems for storing, transmitting and converting signals. The model describes the internal states of the transducer and the transfer behavior between input and output both in the small-and large-signal domain. This information is the basis for measurement applications, quality assessment, failure diagnostics and for controlling the transducer actively. The identification of linear and nonlinear parameters Pand Pof the model without systematic error (bias) is the objective of the current invention. This is achieved by using a transformation systemto estimate the linear parameters Pand the nonlinear parameters Pwith separate cost functions.

Optimal estimation of transducer parameters

The invention relates to an arrangement for measuring and assessing properties of a system () which transfers an electrical, mechanical or acoustical signal or converts an excitation signal x into another signal y. An error system () models the transfer behavior of the system, estimates a desired output signal y', and generates an error signal e which reveals the excess distortion and disturbances of the output signal y at any time instant t, and can reveal peak values of transient distortion having low power which might otherwise be masked by noise and regular distortion. The error signal is supplied to an assessment system (), where convenient distortion measures are calculated and the distortion is displayed versus properties of the signal (e.g., instantaneous frequency and amplitude). The assessment system may also generate a control output () to modify signal x to ensure an optimal excitation of the system.

Signal distortion measurement and assessment system and method

The invention relates to an arrangement for converting an electric input signal into an acoustic or a mechanical output signal comprising a transducer 19, a controller 15 and a parameter detector 17. The output 23 of the controller is connected via the parameter detector to the terminals of the transducer. The controller has a parameter vector input 24 to change the linear or nonlinear transfer characteristic of the controller between its control input 13 and control output 23. The parameter detector comprises an error circuit 31 and update circuit 33. The error circuit 31 measures an electric signal at the terminals of the transducer and generates an error signal e(t) which describes the difference between the measured electric signal and an estimated electric signal derived from the output signal or other state signals of the controller. The update circuit 33 estimates transducer parameters by minimizing the amplitude of the error signal. The estimated parameters are supplied both to the error circuit 31 and to the controller 15 to adjust the controller to the particular transducer and to compensate for distortion in the mechanical or acoustic output signal.

Adaptive controller for actuator systems

This invention relates to an arrangement (1) for protecting transducer (3) which converts an electric signal into an acoustic or a mechanic signal against overload and destruction. The arrangement is connected to the electric terminals of the transducer (3) and changes the electric input signal under overload condition. A reference filter (6) connected with the electric input of the transducer provides a monitored signal x(t) related to the load of the transducer (3) to a controller (7). If the amplitude of the monitored signal x(t) exceeds an prescribed threshold value the controller (7) activates a feedback loop realized by the reference filter (6), multiplier (8) and summer (5). This invention provides an effective protection of the transducer with a minimum of elements by using the reference filter (6) as both a signal detector and a controlled attenuation element. Because the activated protection system has approximately the inverse transfer response of the reference filter the spectral components with the highest amplitude in x(t) are attenuated primarily.

Overload protection circuit for transducers

This invention relates to an arrangement (14) for protecting a transducer (2) which converts an electric signal into an acoustic or a mechanic signal against overload and destruction. The arrangement is connected to the electric terminals of the transducer and changes the electric input signal under overload condition. This protection arrangement comprises a controller (15), a monitor (16) and an envelope detector (17). The monitor (16) provides a signal indicating the electric or mechanic load of the transducer (2). The peak value of the signal is anticipated by using a predictive filter in the envelope detector (17) or a delay element in the controller (15). If the predicted peak value exceeds an defined limit an attenuation element in the controller (15) is activated and the input signal is changed in time to prevent an overload of the transducer. This invention provides protection of the loudspeaker with a minimum of signal distortion and allows to reduce the head room of the transducer and to convert signals with a higher amplitude.

Predictive protection arrangement for electroacoustic transducer

This invention regards an arrangement to correct the linear and nonlinear transfer behavior of electro-acoustical transducers, consisting of an electro-acoustical transducer, a distortion-reduction network connected to its input terminals, and a support system to fit the distortion-reduction network to the transducer. The distortion-reduction network shows nonlinear transfer characteristics obtained from modelling the transducer and thus changes the electrical signal such that the nonlinear effects of the network compensate for the nonlinear behavior of connected transducer. The result is an overall system with reduced distortion and improved linear transfer behavior. A fitting technique and system is used to change the parameters of the electrical network automatically to fit the actual transfer characteristics of the distortion reduction system to the transducer. Several mechanisms, unique to each transducer, are responsible for generation of nonlinear distortion.

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Dresden, Germany

Wolfgang J Klippel