Hewlett-Packard Development Company, L.p.

Ultrahaptics IP Ltd

Hewlett-Packard Development, L.p.

Ultraleap Limited

Rafel Jibry

Peter Arthur Walsh

Benjamin John Oliver Long

Michele Iodice

Robert Morling

Brian Alan Kappus

Thomas Andrew Carter

Jonathan Peter Buckingham

Andrew Hana

Gregory Keith Trezise

Neil Thomas Hutchon

Christopher Huw Williams

Orestis Georgiou

Allan Hodkinson

Mantalena Sarafianou

Darren Edward Kent

Brian Kappus

Described herein are techniques for tracking objects (including human body parts such as a hand), namely: 1) two-state transducer interpolation in acoustic phased-arrays; 2) modulation techniques in acoustic phased-arrays; 3) fast acoustic full matrix capture during haptic effects; 4) time-of-flight depth sensor fusion system; 5) phase modulated spherical wave-fronts in acoustic phased-arrays; 6) long wavelength phase modulation of acoustic field for location and tracking; and 7) camera calibration through ultrasonic range sensing.

Tracking in haptic systems

Phased array systems rely on the production of an exact carrier frequency to function. Reconstructing digital signals by specified amplitude and phase is accomplished explicitly by inducing frequency shifts away from a base frequency implied by phase changes. Shifting the carrier frequency of a digitally controlled phased array while preserving the timing of the individual phase pulses enables more efficient driving of the phased array system when the phase of the drive signals change dynamically in time.

Variable phase and frequency pulse-width modulation technique

A method for object tracking is presented based on the similarity of waveforms recorded at the receiving elements of the array. A rectangular array of acoustic transducers is divided into four quadrants, on the basis that each quadrant contains a receiving element in its center. Each of the four recorded waveforms are compared against each of the remaining waveforms to identify either absolute similarity of the signal characteristics, which would denote absence of the object, or identifying a waveform being the least similar from the rest, hence pointing to a part of the array above which the object is located. Further, source localization algorithms are used for ill-posed scenarios where the distance between receivers is on the same order of magnitude of the dimensions of the tracked object and of the tracking distances.

Tracking techniques in haptic systems

Data storage and retrieval methods and apparatus are provided for facilitating data de-duplication for serial-access storage media such as tape. During data storage, input data is divided into a succession of chunks and, for each chunk, a corresponding data item is written to the storage media. The data item comprises the chunk data itself where it is the first occurrence of that data, and otherwise comprises a chunk-data identifier identifying that chunk of subject data. To facilitate reconstruction of the original data on read-back from the storage media a cache () is used together with a database (R), stored on the media, that includes for each duplicated chunk, the location of the corresponding chunk of subject data.

Data de-duplication for serial-access storage media

Multi-rate oversampling of analog signals in storage devices is described. A method of processing an analog signal derived from a storage medium in a storage device includes: filtering the analog signal with an anti-alias filter having a fixed cut-off frequency related to a target sampling rate; sampling the analog signal using an over-sampling rate of a plurality of over-sampling rates provided by a variable-rate analog-to-digital converter (ADC) to produce an over-sampled digital signal; and filtering the over-sampled digital signal using a decimation filter of a plurality of decimation filters provided by a digital signal processor (DSP) to produce a digital signal having the target sampling rate.

Multi-rate oversampling of analog signals in storage devices

A signal processing device with dynamic phase detector switching includes a first phase detector of a first type, a second phase detector of a second type, and a mixing device to switch between using output from the first phase detector and output from the second phase detector in real time based on specified changes in an input signal being fed to the signal processing device.

Dynamic phase detector switching

An apparatus recovers synchronous data samples from an asynchronously over-sampled stream of data samples derived from an input signal the spectral characteristic of which is subject to variation. The apparatus comprises an FIR filter having an input for receiving the asynchronously over-sampled stream of data samples and for producing equalised asynchronous samples. A signal sample reconstruction means reconstructs the synchronous data samples from the equalised asynchronous data samples. An automatic gain control loop is responsive to the reconstructed data samples to apply gain control for producing gain controlled reconstructed samples. A timing recovery means is responsive to the gain controlled reconstructed samples to provide timing information to the signal sample reconstruction means. A coefficient adaptation control loop is responsive to equalised reconstructed asynchronous data samples substantially unaffected by the automatic gain control for adapting the FIR filter coefficients to the variations in the spectral characteristics of the input signal.

Recovering data samples

One embodiment of an equalizer circuit has an FIR filterin the asynchronously oversampled domain with a filter coefficient adaptation module that adapts the filter coefficients to the transfer function of a data read channel. Applications include tape drives, drives for optical and magnetic discs as well as receivers. The filter adaptation is performed on the basis of an error signal delivered by a slicerwhich operates on synchronous samples after timing recovery and sample reconstruction.

Equaliser circuit

A data read system comprising a read channel for processing a signal, and a diagnostic controller in communication with the read channel. The diagnostic controller is configured to measure at least one metric of the read channel during processing of a signal containing unknown data. The measured metric is then compared against a stored nominal metric and a warning is generated in response to a result of the comparison. In particular, the warning is generated only if the difference between the measured metric and the stored nominal metric exceeds a threshold.

Predictive diagnosis of a data read system

A data read channel for receiving a signal containing a data stream of different types of data and recovering data therefrom, the channel comprising a main data read channel operable to output a stream of recovered data and a branch from the main data read channel comprising a signal analyser to determine the type of data from the data stream of different data types flowing in the main data read channel and a controller operable to control at least one element of the main data read channel in response to the type of data identified by the signal analyser from the data stream.

Data read channel and method of controlling the same

Drop-outs in a data read channel having one or more controllable elements are managed. A data read channel derives a signal having at least one drop-out characterising parameter from which data are to be recovered. The signal from the data read channel is tapped and compared with at least one drop-out characterising parameter of the tapped signal with two or more thresholds to categorise the drop-out. One or more elements of the data read channel is controlled in response to the category of the drop-out.

Drop-out management system and method

A data reader derives a signal on reading a data holding medium. The data reader has processing circuitry to process the signal. The processing circuitry includes a filter having a variable cut-off frequency, a velocity signal generator that produces a signal corresponding to the velocity of the data holding medium, and a processor. The reads the velocity signal and sets the filter cut-off frequency. Calibration data derived during a calibration operation of only the particular data reader determines the filter cut-off frequency for different speeds of the medium during normal read operations of the medium.

Data readers

A processor processes data read from plural data tracks on a data-containing medium. The data tracks include markers. The processor determines if markers are detected in a predetermined number of the tracks within a predetermined time interval starting with detection of a first marker. In first and second embodiments, the number equals all the read tracks and less than all the read tracks. In the second embodiment, the processor asserts the markers into the data associated with the tracks that do not have detected markers.

Data storage reading device and method

Encoded data is decoded by a receiver for an analogue input signal that is converted into a digital signal. A detector produces a sequence of data representative of the analogue signal, a decoder for the sequence of data outputs data indicating that a sequence includes an error. An event detector detects an event which substantially alters or destroys the analogue input signal. The decoder outputs data corresponding to the or each sequence resulting from the altered or destroyed analogue input signal indicating that the sequence is incorrect.

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Bristol, United Kingdom

Rafel Jibry