Ultrahaptics IP Ltd

Ultraleap Limited

Ultrahaptics Ilp Ltd

Benjamin John Oliver Long

Thomas Andrew Carter

Sriram Subramanian

Brian Alan Kappus

Justin Rorke Buckland

Adam John Robert Jackson

Amaru Daniel Araya-Williams

Robert Charles Blenkinsopp

Rafel Jibry

Michele Iodice

Adam Daniel Harwood

Sue Ann Seah

Philip Jones

William Thierry Alain Frier

Orestis Georgiou

David Beattie

Rory Clark

William Wren

Adam Price

Salvador Catsis

Rob Malkin

David Philip Tester

Brian Kappus

Adam Harwood

Jonathan Martinez MUÑOZ

Andrew Thomas Carter

Simon Deely

A method for specifying desired quantities of the energy flux of the combined waves of acoustic radiation pressure to apply producing a mid-air haptic pushing force, which has the effect of simultaneously reducing the harmonic distortion present is described. Further, a method for communicating only the summaries of acoustic field contributions at the required locations in the form of summed portions of the relatively small matrix whose row and column count depend only on the control point count is described. Further, phased arrays of ultrasonic speakers can produce a relatively large amount of acoustic energy which is usually directed in a specific direction or focused to a particular point depending on the application of the array. Further, to allow the system to be driven more strongly than usual, the complex-valued linear system that governs the drive signal to each control point is solved twice. Further, to achieve mid-air haptics with high precision the radiation pressure generated must be modelled accurately.

Features of airborne ultrasonic fields

An acoustic matching structure is used to increase the power radiated from a transducing element with a higher impedance into a surrounding acoustic medium with a lower acoustic impedance. The acoustic matching structure consists of a thin, substantially planar cavity bounded by a two end walls and a side wall. The end walls of the cavity are formed by a blocking plate wall and a transducing element wall separated by a short distance (less than one quarter of the wavelength of acoustic waves in the surrounding medium at the operating frequency). The end walls and side wall bound a cavity with diameter approximately equal to half of the wavelength of acoustic waves in the surrounding medium. In operation, a transducing element generates acoustic oscillations in the fluid in the cavity. The transducing element may be an actuator which generates motion of an end wall in a direction perpendicular to the plane of the cavity to excite acoustic oscillations in the fluid in the cavity, and the cavity geometry and resonant amplification increase the amplitude of the resulting pressure oscillation. The cavity side wall or end walls contain at least one aperture positioned away from the center of the cavity to allow pressure waves to propagate into the surrounding acoustic medium.

Blocking plate structure for improved acoustic transmission efficiency

The present invention concerns a method and apparatus for the modulation of an acoustic field for providing tactile sensations. A method of creating haptic feedback using ultrasound is provided. The method comprises the steps of generating a plurality of ultrasound waves with a common focal point using a phased array of ultrasound transducers, the common focal point being a haptic feedback point, and modulating the generation of the ultrasound waves using a waveform selected to produce little or no audible sound at the haptic feedback point.

Method and apparatus for producing an acoustic field

An acoustic field may be produced from a transducer array having known relative positions and orientations In this acoustic field, one or more control points may be defined. An amplitude may be assigned to the control point. Mid-air haptic effect for a virtual object on a human body part may be generated by moving the control point in a single closed curve comprising a plurality of curve segments. The single closed curve traverses at least one location where the human body part intersects with the virtual object. Additionally, a user may interact with virtual three-dimensional content using the user's hands while a tracking system monitoring the user's hands, a physics engine updates the properties of the virtual three-dimensional content and a haptic feedback system provides haptic information to the user.

Three-dimensional perceptions in haptic systems

Method and apparatus for modulating haptic feedback

A digital signal generation assumes that a base frequency (the frequency with which the primitive phase angles are specified relative to) is equal to the carrier frequency for all relevant times. But this causes errors in the digital signals output to each array element transducer. Thus, it is necessary for the development of a signal generation system that is capable of producing a digital signal using the free selection of amplitude and phase. This is used to produce a substantially error-free signal that preserves the amplitude and phase relative to a constant base frequency while allowing the carrier frequency to vary.

Reducing harmonic distortion by dithering

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

A system providing various improved calibration techniques for haptic feedback is described. An acoustic field is defined by one or more control points in a space within which the acoustic field may exist. Each control point is assigned an amplitude value equating to a desired amplitude of the acoustic field at the control point. Because complete control of space is not possible, controlling the acoustic field at given points yields erroneous local maxima in the acoustic field levels at other related positions. In relation to mid-air haptic feedback, these can interfere in interactions with the space by creating secondary effects and ghost phenomena that can be felt outside the interaction area. The level and nature of the secondary maxima in the acoustic field is determined by how the space is controlled. By arranging the transducer elements in different ways, unwanted effects on the acoustic field can be limited and controlled.

Calibration techniques in haptic systems

Defining critical spacing is necessary for steering of parametric audio. Comparing steering measurements both with and without a waveguide leads to a conclusion that the diffuse phyllotactic grating lobe contributes audio and is to blame for poor steering. In addition, the waveguide needs to function with correct phase offsets to achieve the steering required for performance. Arranging tubes so that the array configuration changes from rectilinear to another distribution is useful when the waveguide is short of critical spacing or constrained for space. Array designs may also capitalize on rectilinear transducer design while having the benefits of a transducer tiling that has irrational spacing to promote the spread of grating lobe energy.

Acoustic transducer structures

Various techniques for driving phased array systems are described, specifically intended for acoustic phased arrays with applications to mid-air haptics, parametric audio, acoustic levitation and acoustic imaging, including a system: 1) that is capable of mitigating the effect of the changes in the air to provide a consistent haptic experience; 2) that produces trap points in air; 3) that defines phased-array optimization in terms of vectors for the production of more consistent haptic effects; 4) that defines one or more control points or regions in space via a controlled acoustic field; 5) that uses a reduced representation method for the construction of acoustic basis functions; 6) that performs efficient evaluation of complex-valued functions for a large quantity of throughput; 7) that generates a Krylov sub-space of a matrix; and 8) that maximizes an objective described by different control points and/or regions to those used to create the acoustic basis functions.

Driving techniques for phased-array systems

To resolve an issue related to the calibration of optical cameras in transducer-based mid-air haptic systems, the magnification of the motion induced on an optical camera by an acoustic field modulated at specific frequencies reveals very small temporal variations in video frames. This quantized distortion is used to compare different acoustic fields and to solve the calibration problem in an automatized manner. Further, mechanical resonators may be excited by ultrasound when it is modulated at the resonant frequency. When enough energy is transferred and when operating at the correct frequency, a user in contact with the device can feel vibration near areas of largest displacement. This effect can be exploited to create devices which can produce haptic feedback while not carrying a battery or exciter when in the presence of an ultrasonic source.

Haptic effects from focused acoustic fields

A system providing various improved processing techniques for haptic feedback is described. An acoustic field is defined by one or more control points in a space within which the acoustic field may exist. Each control point is assigned an amplitude value equating to a desired amplitude of the acoustic field at the control point. Transducers are then controlled to create an acoustic field exhibiting the desired amplitude at each of the control points. When human skin interacts with the acoustic field, vibrations of the skin are interpreted by mechanoreceptors being excited and sending signals to the brain via the nervous system. Improved processing techniques allow for more efficient real-world operation.

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Bristol, United Kingdom

Benjamin John Oliver Long