30results about How to "Minimize error signal" patented technology

A method for cancelling co-channel interference in a multi-carrier communication system includes receiving a serial baseband multi-carrier signal including at least one desired signal and at least one interference signal over at least one receiving branch, and converting the received multi-carrier signal into a plurality of baseband sub-carrier signals. Co-channel interference in each sub-carrier signal is cancelled by subtracting an estimated desired received sub-carrier signal and an estimated interference sub-carrier signal from a received sub-carrier signal. The sub-carrier signals are converted to a multi-carrier output signal comprising the desired signal.

A door operator for controlling operation of a door, the door operator having a motor to open the door against a spring force, the door operator further comprising a door position sensor for transmitting a signal indicative of door position; and among other things, calculates a door moment of inertia based on a net torque and the time for the door to reach a predetermined angle from the closed position. Also provided is a door operator that compares door speed to a desired door speed based on a door speed-position profile and generates a door speed error signal and minimizes the door speed error signal by adjusting the braking load resulting from charging a chargeable battery using the motor as a generator.

A flight control system for an aircraft receives a selected value of a first parameter, which is either the airspeed or inertial velocity of the aircraft. A primary feedback loop generates a primary error signal that is proportional to the difference between the selected value and a measured value of the first parameter. A secondary feedback loop generates a secondary error signal that is proportional to the difference between the selected value of the first parameter and a measured value of a second flight parameter, which is the other of the airspeed and inertial velocity. The primary and secondary error signals are summed to produce a velocity error signal, and the velocity error signal and an integrated value of the primary error signal are summed to produce an actuator command signal. The actuator command signal is then used for operating aircraft devices to control the first parameter to minimize the primary error signal.

Set forth herein are methods and systems for determining a rechargeable (i.e., secondary) battery's capability in real time, including how much power and energy can be discharged or charged, by compensating for the limitations of the standard battery model for cathode electron and ion transport restrictions in a solid-state battery. Set forth herein is also an equivalent circuit for each layer of a layered cathode (i.e., positive electrode) which is created using resistive, capacitive, and storage elements, including a state-of-charge (SOC) state variable and an SOC-dependent voltage source. In some embodiments, each layer is connected to adjoining layers using resistive elements to model ion and electron transport. In some embodiments, bulk ohmic resistance and ion exchange external to the electrode is represented using a Randles cell equivalent circuit.

Apparatus and a corresponding method for processing speech signals in a noisy reverberant environment, such as an automobile. An array of microphones (10) receives speech signals from a relatively fixed source (12) and noise signals from multiple sources (32) reverberated over multiple paths. One of the microphones is designated a reference microphone and the processing system includes adaptive frequency impulse response (FIR) filters (24) enabled by speech detection circuitry (21) and coupled to the other microphones to align their output signals with the reference microphone output signal. The filtered signals are then combined in a summation circuit (18). Signal components derived from the speech signal combine coherently in the summation circuit, while noise signal components combine incoherently, resulting in composite output signal with an improved signal-to-noise ratio. The composite output signal is further processed in a speech conditioning circuit (20) to reduce the effects of reverberation.

Systems and methods automatically compensate for long-term drift of frequency standards or references used by transmitting and receiver terminals to avoid manual adjustment of the terminals to bring them back within operating tolerances and minimize communications outages caused by inability of the system to otherwise accommodate for such drift. The present invention may provide automatic band selection to maintain a modulated carrier within an operating range of an automatic frequency control or tracking capability of a communication device. This may be accomplished by selecting an appropriate reference signal used to control a center frequency of an automatic frequency control circuit (such as a PLL) or used to convert the carrier frequency of the modulated carrier to fall within the operating range of the automatic frequency control circuit and / or by causing the transmitting station to at least partially correct the frequency discrepancy.

An active noise control device detects composite vibration of a vibration transmitting route to which both vibration of a rotating body caused by generation or transmission of drive force of a vehicle and vibration of a wheel generated by contact between the wheel and a road surface are transmitted. A first reference signal for defining a reference waveform of a canceling sound for canceling vibration noise in a vehicle interior is generated based on the composite vibration. The component of the canceling sound for canceling vibration noise of the rotating body is removed from the first reference signal to generate a second reference signal for defining a reference waveform of the canceling sound for canceling vibration noise of the wheel. The canceling sound is outputted based on the second reference signal.

Peak current in a switching converter is controlled using a closed loop to compensate for error caused by delay time in the switching transistor and control logic. A reference value is established that represents a target current value. A compensated reference value is derived from the reference value by the closed loop. A periodic inductor current is formed in the switching converter in response to the compensated reference value. An error signal is formed that is indicative of an amount of time the inductor current exceeds the target current value. The compensated reference value is dynamically adjusted by the compensation closed loop to minimize the error signal.

An input signal is filtered for creating an output signal using an adaptive filter. An error signal is derived from the output signal. The adaptive filter has coefficient whose value can be modified. A value of a coefficient is modified using a derived updating amount. The updating amount is obtained from the product of a value of the input signal, a value of the polarity of the error signal, and a step gain. The step gain has the form 2K with K being an integer and being dependent on a magnitude of the value of the error signal and on a step gain parameter. The updating amount is dependent on both the magnitude and the polarity of the error signal, therefore allowing a precise update of the coefficient. The specific form of the step gain allows a fast derivation of the product.

Embodiments of the present invention provide a method and a system for generating optimal feedforward signal for the seek control to suppress the RTV (Random Transient Vibrations) and the seek acoustic noise. One aspect is directed to a method of providing a revised feedforward signal using an adaptive filter in a feedforward control system for controlling an actuator to move a head to seek a track and settle on the track of a disk in a disk drive apparatus. The method comprises performing a seek operation of the head using an initial feedforward signal; obtaining an error signal at settling after performing the seek operation; determining filter characteristics of the adaptive filter to minimize the error signal; and implementing the adaptive filter having the determined filter characteristics in the feedforward control system to produce a revised feedforward signal for controlling the actuator for moving the head in the disk drive apparatus.

A flight control system for an aircraft receives a selected value of a first parameter, which is either the airspeed or inertial velocity of the aircraft. A primary feedback loop generates a primary error signal that is proportional to the difference between the selected value and a measured value of the first parameter. A secondary feedback loop generates a secondary error signal that is proportional to the difference between the selected value of the first parameter and a measured value of a second flight parameter, which is the other of the airspeed and inertial velocity. The primary and secondary error signals are summed to produce a velocity error signal, and the velocity error signal and an integrated value of the primary error signal are summed to produce an actuator command signal. The actuator command signal is then used for operating aircraft devices to control the first parameter to minimize the primary error signal.

A method for forming a non-iterative time-domain equalizer (TEQ) and apparatus corresponding thereto. A channel response H(z) is followed by a TEQ response A(z) and a residual output B(z) is chosen so that its degree is less than a cyclic prefix. An error signal is formed so that E(z)=H(z)A(z)−B(z). With a unit input, the error signal is set to zero and B(z)=H(z)A(z). Each signal is expressed as a polynomial, having varying degrees, and a having corresponding coefficients. Once expanded, the coefficients of similar degree can be equated on both sides of the equation. The error signal can then be determined in terms of coefficients corresponding to the TEQ and the residual signal. The coefficients of the channel response can be derived from the channel training estimates. The error signal is minimized and the result is solved for in terms of the desired TEQ coefficients.

A method and apparatus for controlling the position of a vehicle on a track so as to provide a slotless racing vehicle game is described. The method involves measuring the lateral position of the vehicle on the track so as to minimise the distance with a user defined lateral position. A measured velocity of the vehicle is then feedback to a steering servo in order to stabilise the vehicle's position at the desired lateral position. In particular, the gain of a controller that generates the input signal for the steering servo is varied with the reciprocal of the square of the speed of the vehicle.

Apparatus and a corresponding method for processing speech signals in a noisy reverberant environment, such as an automobile. An array of microphones (10) receives speech signals from a relatively fixed source (12) and noise signals from multiple sources (32) reverberated over multiple paths. One of the microphones is designated a reference microphone and the processing system includes adaptive frequency impulse response (FIR) filters (24) enabled by speech detection circuitry (21) and coupled to the other microphones to align their output signals with the reference microphone output signal. The filtered signals are then combined in a summation circuit (18). Signal components derived from the speech signal combine coherently in the summation circuit, while noise signal components combine incoherently, resulting in composite output signal with an improved signal-to-noise ratio. The composite output signal is further processed in a speech conditioning circuit (20) to reduce the effects of reverberation.

A method and apparatus for controlling the position of a vehicle on a track so as to provide a slotless racing vehicle game is described. The method involves measuring the lateral position of the vehicle on the track so as to minimize the distance with a user defined lateral position. A measured velocity of the vehicle is then feedback to a steering servo in order to stabilize the vehicle's position at the desired lateral position. In particular, the gain of a controller that generates the input signal for the steering servo is varied with the reciprocal of the square of the speed of the vehicle.

Systems and methods for stabilizing laser frequency based on an isoclinic point of an atomic or molecular medium are provided herein. A system may include: a transmission cell containing a gas and configured to transmit light from the laser, the gas having an absorption spectrum with an isoclinic point; a photodiode generating an output based on an amplitude of transmitted laser light; and circuitry configured to tune the frequency of the laser to the isoclinic point of the absorption spectrum based on the output. The absorption spectrum may have first and second overlapping peaks respectively corresponding to first and second transitions of the gas, the isoclinic point being a saddle point between the first and second peaks. The first and second peaks may have substantially equal amplitude as one another and / or may broaden substantially equally as each other as a function of a physical parameter of the gas.

A method for forming a non-iterative time-domain equalizer (TEQ) and apparatus corresponding thereto. A channel response H(z) is followed by a TEQ response A(z) and a residual output B(z) is chosen so that its degree is less than a cyclic prefix. An error signal is formed so that E(z)=H(z)A(z)−B(z). With a unit input, the error signal is set to zero and B(z)=H(z)A(z). Each signal is expressed as a polynomial, having varying degrees, and a having corresponding coefficients. Once expanded, the coefficients of similar degree can be equated on both sides of the equation. The error signal can then be determined in terms of coefficients corresponding to the TEQ and the residual signal. The coefficients of the channel response can be derived from the channel training estimates. The error signal is minimized and the result is solved for in terms of the desired TEQ coefficients.

A signal is reproduced from a recording medium. The reproduced signal is sampled in response to a clock signal to get a sampling-resultant signal. A transversal filter includes a delay line having taps and delaying the sampling-resultant signal, multipliers for multiplying only alternate ones among signals appearing at the taps by tap coefficients to get multiplication results, and an adder for adding the multiplication results into a filtering-resultant signal. A temporary decision device operates for calculating a temporary decision value of the filtering-resultant signal according to a temporary decision procedure, for calculating a difference between the temporary decision value of the filtering-resultant signal and an actual value thereof, and for generating an error signal in response to the calculated difference. The tap coefficients used in the transversal filter are controlled in response to the error signal and the reproduced signal to minimize the error signal.

A laser-source assembly that is configured to illuminate a vacuum chamber containing atoms in the gaseous state so as to implement a cold-atom inertial sensor, the atoms having at least two fundamental levels that are separated by a fundamental frequency difference comprised between 1 and a few gigahertz, the assembly comprises: a master laser that emits a beam having a master frequency; a first control loop that is configured to stabilize the master frequency of the master laser on a frequency corresponding to half a set frequency of an atomic transition between a fundamental level and an excited level of the atoms; a slave laser that has a slave frequency; and a second control loop that is configured to stabilize the slave frequency of the slave laser with respect to the master frequency, the slave frequency being offset with respect to the master frequency successively, over time, by a first preset offset value, a second preset offset value, and a third preset offset value, the offset values being comprised in an interval equal to half the fundamental frequency difference plus or minus a few hundred MHz.

An adaptive interference cancellation apparatus for cancelling a side lobe between neighboring cells installed in a repeater and capable of improving quality of a communication signal and preventing frequent handover by maintaining a serving base station signal among repeater signals and cancelling an interference signal from a neighboring cell is provided. The adaptive interference cancellation apparatus for a side lobe between neighboring cells, which is installed in a mobile communication repeater system comprising an omni-directional antenna, includes: three directional antennas installed around the omni-directional antenna; an output signal selector configured to select and output two of three directional antenna incident signals; and an adaptive noise canceller configured to adaptively filter the two directional antenna incident signals output from the output signal selector, estimate a noise reference signal, and extract a serving base station signal by subtracting the estimated noise reference signal from an omni-directional antenna incident signal.

Peak current in a switching converter is controlled using a closed loop to compensate for error caused by delay time in the switching transistor and control logic. A reference value is established that represents a target current value. A compensated reference value is derived from the reference value by the closed loop. A periodic inductor current is formed in the switching converter in response to the compensated reference value. An error signal is formed that is indicative of an amount of time the inductor current exceeds the target current value. The compensated reference value is dynamically adjusted by the compensation closed loop to minimize the error signal.

An apparatus for providing a supply voltage to a device under test includes: a controlled source; a switchable resistor circuited between the output of the controlled source and a dut port, having a comparatively smaller first resistance in a first switch state and a second resistance in a second switch state; a regulator that provides a control signal to the controlled source, to regulate a voltage to be provided to the dut. The apparatus changes a switch state of the switchable resistor while a voltage is provided to the dut via the switchable resistor. The apparatus injects a compensation signal into a control loop including the regulator, the controlled source and the switchable resistor, to thereby cause a change of the voltage provided by the controlled source, to at least partially compensate a change of a voltage drop across the switchable resistor.

An adaptive interference cancellation apparatus for cancelling a side lobe between neighboring cells installed in a repeater and capable of improving quality of a communication signal and preventing frequent handover by maintaining a serving base station signal among repeater signals and cancelling an interference signal from a neighboring cell is provided. The adaptive interference cancellation apparatus for a side lobe between neighboring cells, which is installed in a mobile communication repeater system comprising an omni-directional antenna, includes: three directional antennas installed around the omni-directional antenna; an output signal selector configured to select and output two of three directional antenna incident signals; and an adaptive noise canceller configured to adaptively filter the two directional antenna incident signals output from the output signal selector, estimate a noise reference signal, and extract a serving base station signal by subtracting the estimated noise reference signal from an omni-directional antenna incident signal.

One or more devices, systems, methods and storage mediums for optical imaging medical devices, such as, but not limited to, Optical Coherence Tomography (OCT), single mode OCT, and / or multi-modal OCT apparatuses and systems, and methods and storage mediums for use with same, for performing automated polarization control, polarization diversity and / or balanced detection are provided herein. One or more embodiments may achieve polarization diversity and balanced detection (or photo-detection) under any imaging circumstances. One or more embodiments, may achieve polarization control functionality regardless of whether such control is automatic or manual. Additionally, one or more embodiments may achieve automated polarization control, may achieve balanced detection (or photo-detection), and / or may address potential disturbances, such as, but not limited to, polarization drift over time, temperature and / or mechanical perturbations or variations. One or more embodiments may include an optical receiver where polarization diversity and balanced detection may be optimized via motorized controls.

This invention is designed for use in transmission of data between downhole module in a wellbore and a controlling module at the surface. The invention provides an apparatus for receiving data signals from a telemetry module comprising first and second adaptive equalisers, and in which in a first modulation mode the coefficients of the first adaptive equaliser are updated until an error signal falls below a predetermined threshold and in a second modulation mode the coefficients of the first adaptive equaliser are locked and coefficients of the second adaptive equaliser are updated to continually minimise an error signal in which the number of bits encoded by the symbols of the first signal in an initial modulation mode is fewer than the number of bits encoded by the symbols of the second signal in a subsequent modulation mode.