Haptic interface

• US 20040169483A1
• Filed: 01/05/2004
• Published: 09/02/2004
• Est. Priority Date: 07/10/2001
• Status: Active Grant

• Current Assignee: British Telecommunications PLC (BT Group PLC)
• Original Assignee: British Telecommunications PLC (BT Group PLC)
• Inventors: Hardwick, Andrew J
• Granted Patent: US 8,169,401 B2
• Time in Patent Office: Days
• US Class Current: 318/560
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06F 3/016 Input arrangements with force or tactile feedback as computer generated output to the user

Abstract

Simulated textures whose parameters are held with object model data in a data store 5 are modified in accordance with data held in a data store 6 which data defines a Gamma correction factor 73 previously determined for each identified user. The gamma correction factor is determined by outputting to a Haptic Output interface a texture simulation comprising spaced grooves or ridges. By correlating user response to the perceived “feel” of the texture (rough, medium or smooth scale for example) the user'"'"'s perceptual factors can be determined. Subsequently applying the perceptual factors to effect a mathematical adjustment (power) of texture in simulation algorithms allows output simulations to be adapted so that each user has a corresponding perception of the simulated objects.

Claims

1. A method of calibrating a haptic interface comprising the steps of outputting to a touchable device a signal to cause simulation of a first pattern, determining from user response an index number for the first pattern, outputting to said touchable device at least one further signal causing simulation of at least one further pattern and determining from user response a respective index number for each such further pattern to provide a set of user-specific index numbers, and comparing the set of index numbers with a predetermined set of known index numbers representing a base exponent value to determine a mathematical parameter set defining user-specific correction factors to be applied to haptics signalling outputs.

2. A method of calibrating a haptic interface as claimed in claim 1 further comprising outputting a series of signals defining grooves of varying width and measuring the user response thereto to determine the user specific correction factors.

3. A method of calibrating a haptic interface as claimed in claim 1 or claim 2 in which the correction factors determined define the Stevens exponent for the user.

4. A method of calibrating a haptic interface as claimed in any one of claims 1 to 3 in which a plurality of correction factors are derived, a respective correction factor being determined for each of a plurality of user stimulating effects.

5. A method of outputting control signals to a haptic output interface comprising the steps of storing data defining signals to be output to cause the haptic output interface to simulate a display, recovering said data in response to user input, modifying the data by application of determined user-specific correction factors and outputting signals determined by the modified data to cause the haptic output interface to provide a user-specific display so that perception of the display between user'"'"'s having differing correction factors is substantially similar.

6. A method of outputting control signals as claimed in claim 5 in which the user specific correction factor is selected from a plurality of stored user specific correction factors in dependence upon the haptic output interface currently in use.

7. A method of outputting control signals as claimed in claim 5 or claim 6 in which a plurality of user specific correction factors, each determined in respect of a particular simulated sense, are used to effect user specific corrections to the output.

8. Apparatus for determining correction factors to be used in adaptation of haptic output signals, the apparatus comprising processing means and signal output means coupled to a haptic output interface, the processing means storing data defining a multiplicity of display effects, the processing means being arranged to cause output of a series of signals defining known textures to the haptic output interface and to record user'"'"'s reaction to said outputs, the processor determining from said user'"'"'s respective reactions to said outputs a correction factor to be used with each of said stored display effects to allow the effects when displayed to be perceived as substantially similar to a known perception of the effects.

9. Apparatus according to claim 8 in which respective correction factors for each of a plurality of users are stored in the processing means whereby on subsequent usage of the apparatus input of a user identity may be used so that a user may return to the apparatus without requiring re-calibration.

10. Apparatus according to claim 8 or claim 9 further comprising transmitting the determined correction factors or Steven'"'"'s exponent values determined by a first apparatus to other locations whereby a known gamma correction factor for a particular user may be shared by multiple apparatuses.

11. Apparatus according to claim 10 in which the gamma correction factor is used by a central processor connected by way of a connection oriented or connectionless network to a haptic output interface at a remote location

12. Apparatus according to claim 11 in which a respective interface is provided for each of a plurality of users to enable each user to interact simultaneously with the apparatus, the processing applying respective correction factors or Steven'"'"'s exponent factors to corresponding haptic output signals so that each user has a substantially similar perception of the haptics output.

13. Apparatus according to any one of claims 8 to 12 in which a respective plurality of user correction factors are stored for each user, each such correction factor being stored in respect of a particular haptic output device, the respective correction factor being selected from the plurality of correction factors in dependence upon the haptic output device(s) connected.

14. Apparatus according to any on e of claims 8 to 13 in which a respective correction factor is determined for each tactile sense to be simulated, one or more correction factors for a particular user being applied to output signalling in dependence upon the simulated senses.