GB2291167A

GB2291167A - Computer input device eg for virtual reality

Info

Publication number: GB2291167A
Application number: GB9418491A
Authority: GB
Inventors: Jonathan David Waldern; Richard Holmes
Original assignee: VIRTUALITY
Current assignee: VIRTUALITY
Priority date: 1994-07-15
Filing date: 1994-09-14
Publication date: 1996-01-17
Also published as: GB9418489D0; GB9418487D0; GB9414373D0; GB2291166A; GB2291165A; GB9418491D0

Description

2291167 COMPUTER 1= DEVICE This invention relates to carputer input

devices generally and more particularly but not exclusively to a human cter interface (HCI) device adapted to translate human body movement into a variable electrical control signal, typically for use in conjunction with virtual reality camputer software applications.

In the field of virtual reality camputer simulation the increased resolution of graphics in model space, i.e. that viewed in the virtual world, which can be manipulated in real time has resulted in a proliferation of man-machine control interfaces. For manipulating the caricature of a hand in model space hitherto it has been suggested that an HCI in the form of a exo-skeletal glove be used. Such gloves require sensors to determine the relative digit position as well as spatial position news to mionitor the position of the hand relative to a fixed datum.

Spatial position sensing means can be provided by transmitter or receiver means of knawn type. Typically, in glave type WIls a housing for these means could be provided disposed adjacent the back of the hand. If wrist flexure is also being measured then these mans could alternatively be disposed adjacent the wrist.

The remainder of the glove houses a multiplicity of input sensors to monitor finger and/or joint miovement such as those which rely on hand manipulation affecting the transmission path between 1ED's and associated photodetectors. ExalTples of such sensors are described in European Patent Specification No 0 211 984. Another suggested way of measuring finger movement by joint flexure is to fit the glave with tendon like linkages between fixings one side of a given joint and a respective strain gauge or rectilinear operable transducer (e. g. LVDT - Linear Variable Differential Transducers) anchored at the other side of said joint. In yet another suggested way the strain gauges form part of elongate tendrils each attached aver a joint of the hand to form a lgonicueter' adapted to measure joint deflection.

2.

Typically, data input gloves tend to be both bulky and generally difficult to don and doff. To enhance realism it is known to include pressure feedback means in the glove to provide the user with scue degree of concrete feel when an object in model space is contacted by the virtual hand/cursor. Feedback can be provided by electrical solenoids or by inflatable bladders disposed in the glove along the underside of the fingers. for example.

It is an object of the invention to provide inproved cmputer,data, input means.

According to the invention a human ccuputer interface (HCI) device for transmitting signals between part of a human body and a cemputer, the device cairprises pressure transducer news associated with an actuator in the form of a fluid-filled, flexible enclosure with the arrangement providing that deformation of the enclosure resulting fram reverent of said body part will pressurise and actuate the transducer to provide an electrical signal in proportion to the applied pressure.

In a first aspect of the invention the device further comprises a body grippable by the hand of a user, and the pressure transducer ms-ans is fixed relative to the body with the enclosure being disposed so at least in part to be canpressible relative to the body by a digit of the user. The pressure transducer mans may ccuprise a pneumatic/hydraulic pressure transducer and the enclosure be provided by a section of resilient tubing with one end of the tubing being connected so that its interior c=unicates with the transducer and the other end being plugged. Typically, the body is provided by a housing having a rigid back wall adapted to seat against the palm of the user and a rigid front wall adapted to extend behind the fingers of the user, with the front wall having a recessed formation in which the section of tubing can seat and the housing further camprising a flexible outer rane or shroud adapted to extend over at least a part of the front wall to cover the tubing sidewall. The transducer may be retained within the housing adjacent the back wall, one end of the section of tubing my be connected to a pipe connector which extends from the chamber of the housing into the recessed formation, and a 3.

generally inextensible section of pipe may extends between the connector and the transducer. Desirably, the pipe connector is in the form of a Tjoint providing a right-angled fluid passageway and a blind limb which can be used to plug one end of another section of tubing.

Typically, the device further ccuprises a thumb operated electrical switch and/or a thumb operated track-ball attached to the body. In which case, the body niay camprise a m-:dm base portion which houses said transducer and enclosure, and a plug detachable upper crown portion housing said switch and/or track-ball. A retaining strap may be attached to the body which is adapted to extend around the back of the hand of the user gripping the body.

In a second aspect of the invention the device further camprises an exoskeletal structure adapted to worn on the hand. This structure may be in the form of a glove or a mitten. Preferably, it is in the folm of a 'gauntlet' having a backhand portion overlying and attachable to the back of the hand and a plurality of lints extending fram, the body portion so as to extend generally overlying a corresponding plurality of the digits of the hand. The gauntlet may further comprise a wrist portion which can be strapped or otherwise attached to the wrist of the user and which is flexibly connected to the body portion.

Typically, each of the plurality of limbs of the 'gauntlet' is provided with at least one respective downwardly depending ring formtion adapted to form a yoke to surround the corresponding digit(s) of the hand. The base of each ring opposing the respective lirb may be provided with inflatable tactile feedback mans.

Preferably, in this second aspect of the invention the pressure transducer mans ccuprises a pneumatic/hydraulic pressure transducer and the enclosure is provided by a section of resilient tubing disposed so that in use it extends aver a joint of the hand or wrist with one end of the tubing being connected so that its interior cnicates with the transducer and the other end being plugged and with the arrangement providing that flexure of the said joint or wrist results in deformation of 4.

the tubing. The tubing wall may be integrally formed with the exoskeletal structure. Alternatively, the exo-skeletal structure way be formed with an 'aver-size, elongate bore within which the resilient tubing is disposed and with the arrangement providing that on flexure of the bore the tubing is able freely to mc)ve longitudinally.

According to both aforedescribed aspects of the invention an HCI device ccnprises a plurality of transducers and associated enclosures with each actuable by a respective digit of the user. It may also further ccuprise a tranmnitter or a receiver of spatial position sensing mans. In addition the device way further cairprise pressure feedback means associated with the or each enclosure to pravide when desired increased resistance to deformation.

Embodiments of the invention will now be described by way of exanple only and with reference to the acccupanying drawings in which:- Figure 1 is a front view of a haptic HW device in accordance with first embodiment of the invention; Figure 2 is a top view of the haptic H= device shown in Figure J; Figure 3 is a right hand side view of the haptic HCI device sh awn, in Figure 1; Figure 4 illustrates diagraumtically the internal structure of the haptic HCI device oriented as sham in Figure 3 and in accordance with a first embodiment of the invention; Figure 5 is a plan view of a gauntlet 1 type haptic HCI device in accordance with a second embodiment of the invention, with a part of one limb of the gauntlet being shown in partial section, and Figure 6 is an enlarged view of the sectioned portion of Figure 5 when flexed.

5.

The first embodiment of the invention sham in Figures 1 to 4 is in the form of a haptic H= device adapted to be gripped in the palm of the hand of a user and having 'data' input means operable by the fingers and thumb of the hand. The entodiment caiupriLses a body having a moulded plastics housing 1 in two-parts 1A, 1B fixed together by means of pegs 2 (see Figure 4). The body further comprises a plug detachable crown portion 3 and front panel 4. The housing 1 has a back wall 5 which seats in the palm, a crown face 6 against which the portion 3 seats, cable connection port 7 and retention formations generally denoted 8 (shown in detail in Figure 4).

As can be seen in Figure 4, the internal structure camprises electrical connector blocks 9,10 fixed within the housing 1. Block 9 is sandwiched between formations on three of the pegs 2 when the two parts 1A,1B of the housing are fixed together. A cable loam 11 extends through port 7 to provide electrical connection between the blocks 9,10 and associated computer hardware (not shown). A circuit board 12 plugged into connector block 9 has mounted thereon four pressure transducers 13,14,15,16 and associated electrical circuitry. Each of these transducers, typically being pneumatic or hydraulic pressure transducers, is adapted to provide an electrical output in proportion to the fluid pressure to which it is subjected. Typically and desirably, this output is linear, i.e. proportional to the input pressure, although the output may not always be so. Appropriate calibration of the computer hardware will facilitate the use of transducers having a non-linear output.

A front face to the housing 1 is provided by portion 4 which is adapted to extend behind the fingers of a user and which at its upper and lower extent is held captive by the respective formation 8 when the two parts of the housing 1 are fixed together. The portion 4 has a rigid wall 17 having a profile to facilitate being claniped by the fingers of the user. This wall 17 defines an elongate recess into which sections 18,19,20,21 of resilient tubing are seated. A plurality of T-joint pipe connectors 22, 23,24,25,26 extend through the wall 17 with their respective T crossbar lying lengthways in the recess.

6.

Each T-joint pipe connector 22 to 26 has a blind limb 27 of the T crossbar with the remaining limbs pravidmg a respective right-angled fluid passageway. The section 18 of tubing corresponding to the little finger is attached to connector 22 at one end and plugged by the blind limb 27 of connector 23 at the other. Similarly section 19 extends between connectors 23,24; section 20 extends between connectors 24,25, and section 21 extends between connectors 25,26. It will be appreciated that the blind limb of connector 22 and the fluid passageway of connector 26 are redundant. Consequently, connectors 22 and 26 could be replaced respectively by a more appropriate pipe connector and plug.

Relatively inextensible pipes 28,29,30,31 extend respectively between connectors 22,23,24,25 and transducers 13,14,15,16. Consequently, the interior chambers of tubing sections 18 to 21 camminicate with an associated transducer 13 to 16 and the output from each of these transducers relates to the pressure applied to the corresponding section of tubing. Thus, sections 18 to 21 are each an actuator for the associated transducer 13 to 16.

Front portion 4 of the body further ccoprises a flexible rane cover 32 extending generally parallel to the wall 17. The rane 32 extends aver and encloses the sections of tubing 18 to 21 and pipe connectors 22 to 26. The rane 32 is sufficiently flexible to permit compression of the sections of tubing 18,19,20,21 by the light application of pressure by fingers of the user at positions A,B,C,D respectively shown on Figure 3.

The T-joint connectors 22 to 26 are generally rigid, consequently the mmbrane 32 is only ccopressible therebetween thus defining locations/positions A,B,C,D for the fingers of the user. Pressure applied to the rane 32 at positions A,B,C,D (shown in Figure 3) will result in a corresponding electrical 'output' respectively from transducers 18 to 21 or 40 to 43 and mavement of mimbrane 32 in proportion to the pressure applied. Suitably, the body is constructed so that it will accommodate use by people of different hand size and finger reach. If desired the nmbrane 32 my be moulded so as to provide indentations corresponding to locations 7.

A,B,C and D to enable ready location of the fingers of the user.

In an alternative construction (not illustrated) the aforedescribed sections of tubing and connectors are replaced by closed-end sections of tubing each with a connector extending through the rigid wall 17. These replacement connectors are of a form having a hollow spike, adapted to pierce the associated tubing wall to permit communication with the tubing interior. This alternative enables the membrane 32 to be generally compressible along the entire run of tubing sections.

Crown portion 3 of the body is suitably fitted with a track-ball 33 which internally of the portion 3 is provided with a connector 34 plugable into the connector block 10 of the main housing 1. Additional retention means may be provided to ensure that the crown portion 3 remains fixed to the housing 1. it will be appreciated that interchangeable crown portions 3 nay be provided. For example, a crown portion having switches in place of or together with the track-ball 33 could be used. These are disclosed in detail in our co-pending UK Patent Application filed this date with the title "Versatile Thumb-Controlled Haptic Cter Input".

In addition to the aforedescribed 'data, input means, the housing 1 is provided with retention means for a position sensor 35 which may conveniently be the transmitter or receiver of a position sensing device. Thus, the computer hardware receives input from the fingers and thumb of the user whilst being able to monitor the relative spatial position of the hand.

The aforedescribed embodiment is particularly useful when used in association with a virtual reality computer programme application in which a cursor in the shape of a hand or grabber is controlled in model space. The cursor can be provided with four digits controllable by the user gripping the housing 1 with each digit corresponding to a respective one of the user's fingers, i.e. controlled by actuators at or associated with positions A,B,C,D.

Applying a given pressure to one of the positions A,B,C,D will 8.

result in an electrical signal fran the associated transducer which in turn leads to corresponding nmement of the associated digit in model, space. An increased pressure would result in greater nxDvemnt and conversely a lighter pressure would result in less mvemLnt. The user advantageously is able to sense a certain degree of feedback fram the actual movement of their am digits as well as the pressure applied.

Obviously, the grip will vary fram user to user and consequently it would be possible to introduce a bias into the circuitry so that the input device could be custcmised for different users. The ccinpressible tubing, or other like bladder mans could be provided for increasing the pressure within the tubing so that a greater pressure is needed to effect ccupression. thereof. Also, it may be desirable to introduce feedback means to alert the user to contact of digits of the cursor with an object in model space.

In the embodiment illustrated in Figures 5 and 6 the HCI is in the fom of a gauntlet 100, fabricated generally fram plastics or elastcmeric material, having a wrist portion 101 flexibly connected to a backhand body portion 102 by mans of an articulated joint 103. A plurality of elongate flexible limbs 104,105,106,107,108 corresponding to the five digits of the hand extend fram the backhand body portion 102. Downwardly depending fram the end and intermediate regions of the lints 104 to 108 are ring formations 109 which in use are adapted to provide yokes for finger location. To permit flexing of the various limbs and joint of the gauntlet these are fabricated with a ribbed upper structure. This in the case of the joint 103 may also permit a certain degree of twist, i.e. rotational movement about a ccmron axis of body portion 102 relative to the wrist portion 101.

To don the gauntlet 100 a user inserts their fingers through the appropriate yoke/ring formations 109 and clairps the wrist portion 101 and backhand body portion 102 in place by means respectively of velcro straps 110,111. On doing so the user is able to manipulate their hand to cause generally corresponding nxDvement of the gauntlet.

9.

One, other or both housings 112 and 113 on the portions 101, 102 respectively may contain transmitter or receiver weans (not shown) of spatial position sensing apparatus. In addition they will contain pressure transducer weans of the HCI together with associated circuitry. Connection between these circuitry and associated cter hardware (not shown) is by means of cable 114 extending rearwardly from the wrist portion 101. It will be appreciated that such hardwire connection could be replaced by remote radio, infrared or microwave means.

Data' input means comprise the aforementioned transducers each together with an associated elongate closed-end flexible section of tubing or like bladder communicating therewith. The input weans are each arranged to extend along the length, or part of the length, of a respective limb or joint of the gauntlet. This is explained hereinafter with reference to Figure 6 which illustrates limb 106 in partial section and in a flexed attitude, i.e. flexed between a ring formation 109 at the end of the limb and an intermediate ring 109 disposed generally half way along its length.

The limb 106 is provided with a blind bore 115 extending along its entire length. The free, closed-end of bore 115 is located above, the end ring formation 109 and the fixed end of the bore is disposed within the backhand portion 102 and houses a pressure transducer (not shown). CCUULinicating with the transducer and extending along the bore 115 is a section of flexible tubing 116 which is closed at its free end by a plug 117. As can be seen from Figure 6 flexing of the limb 106 results in deformation of the tubing section 116 and it will be appreciated that the amount of deformation is dependent on the degree of flexure.

As the fluid, in this case air, within the tubing section 116 is ccffpressible this results in increased internal pressure on flexing thereof. Self-evidently this will result in an electrical output from the pressure transducer generally in proportion to the degree of flexure. Typically, in virtual reality software applications this output can be 'translated' by the computer hardware into corresponding flexure of an associated 'digit' of a virtuall hand or cursor in model space.

10.

It way be desirable to differentiate nxnren-ent of the limb between the two ring formations 109 fran movement between backhand portion 102 and the closer, i.e. intermediate, ring 109. To do so a length of tubing could be disposed between the end of bore 115 and the intermediate ring 109 ccumudcating with a transducer at that location whilst a second length of tubing extends frctn adjacent the intermediate ring 109 to the transducer located within the backhand portion 102.

Clearly, the aforedescribed input technology can be used to measure flexure of the wrist joint 103. It may be desired that a plurality of sections of tubing are disposed generally parallel within the joint so that differential deformation will occur on twisting.

In addition to the pressure input means described the rings 109 each contain in their base portions a chamber 118 having a port covered by a resiliently flexible rane 119. Fluid may be pumped into each chamber 118 by news of a respective pipeline fed frm a corresponding actuator located in housing 112 or 113. The actuators can be controlled by the computer hardware to provide tactile pressure feedback means.

If desired the aforedescribed transducer-enclosure technology could be utilised in HCI adapted to be actuated by movement of body parts other than the hand. For example, knee or elbow flexure could be measured by a device having a body strapped to above the joint with the end of an elongate enclosure extending fram the body being attached below the joint. In another example the deformation of the enclosure could be effected by inflating the cheeks or stomach movement. It will be appreciated that in certain applications it way be desired to have the body of any HCI device at a fixed position as opposed to held or attached to the human body. Also, in the aforedescribed erbodiments the HCI has been used for intelligent input purposes, although there is no reason why some embodiments could not be used passively merely to record movement of a part of the human body to which it were associated, for example.

Claims

CLAIM:

1. A human computer interface (HCI) device for transmitting signals between part of a human body and a computer, the device comprising pressure transducer mans associated with an actuator in the form of a fluid-filled, flexible enclosure with the arrangement providing that deformation of the enclosure resulting fran movement of said body part will pressurise and actuate the transducer to provide an electrical signal in proportion to the applied pressure.

2. An HCI device in accordance with claim 1, further comprising a body grippable by the hand of a user, wherein the pressure transducer news is fixed relative to the body with the enclosure being disposed so at least in part to be compressible relative to the body by a digit of the user.

3. An HCI device in accordance with claim 2, wherein the pressure transducer means comprises a pneumatic/hydraulic pressure transducer and the enclosure is provided by a section of resilient tubing with one end of the tubing being connected so that its interior communicates with the transducer and the other end being plugged.

4. An HCI device in accordance with claim 3, wherein the body is provided by a housing having a rigid back wall adapted to seat against the palm of the user and a rigid front wall adapted to extend behind the fingers of the user, with the front wall having a recessed formation in which the section of tubing can seat and the housing further comprising a flexible outer rane or shroud adapted to extend over at least a part of the front wall to cover the tubing sidl.

5. An HCI device in accordance with claim 4, wherein the transducer is retained within the housing adjacent the back wall, one end of the section of tubing is connected to a pipe connector which extends from the chamber of the housing into the recessed formation, and a generally inextensible section of pipe extends between the connector and the transducer.

6. An HW device in accordance with claim 5, wherein the pipe 12.

connector is in the form of a T-joint providing a right-angled fluid passageway and a blind limb which can be used to plug one end of another section of tubing.

7. An HW device in accordance with any one of claims 3 to 6, further camprising a thumb operated electrical switch and/or a thumb operated track-ball attached to the body.

8. An H= device in accordance with claim 7, wherein the body ccuprises a main base portion which houses said transducer and enclosure, and a plug detachable upper crown portion housing said switch and/or track-ball.

9. An H= device in accordance with any one of claim 3 to 8, further =prising a retaining strap attached to the body which is adapted to extend around the back of the hand of the user gripping the body.

10. An H= device in accordance with claim 1, further camprising an exoskeletal structure adapted to worn on the hand.

11. An HCI device in accordance with claim 10, wherein the structure is in the form of a glove or mitten.

12. An H= device in accordance with claim 10, wherein the structure is in the form of a Igauntletl having a backhand portion overlying and attachable to the back of the hand and a plurality of limbs extending frcm the body portion -so as to extend generally overlying a corresponding plurality of the digits of the hand.

13. An H= device in accordance with claim 12, wherein the gauntlet further cises a wrist portion which can be strapped or otherwise attached to the wrist of the user and which is flexibly connected to the body portion.

14. An H= device in accordance with any one of claim 12 or 13, wherein each of the plurality of limbs is provided with at least one 13.

respective downwardly depending ring formation adapted to form a yoke to surround the corresponding digit(s) of the hand.

15. An H= device in accordance with claim 14 wherein the base of each ring opposing the respective limb is provided with inflatable tactile feedback means.

16. An H= device in accordance with any one of the claim 10 to 15, wherein the pressure transducer means comprises a pneumatic/hydraulic pressure transducer and the enclosure is provided by a section of resilient tubing disposed so that in use it extends over a joint of the hand or wrist with one end of the tubing being connected so that its interior ccnmmiicates with the transducer and the other end being plugged and with the arrangement providing that flexure of the said joint or wrist results in deformation of the tubing.

17. An H= device in accordance with claim 16, wherein the tubing wall is integrally formed with the exo-skeletal structure.

18. An H= device in accordance with claim 16, wherein the exo-skeletal structure is formed with an aver-size, elongate bore within which the resilient tubing is disposed and with the arrangement providing that on flexure of the bore the tubing is able freely to move longitudinally.

19. An H= device in accordance with any one of claim 2 to 18, wherein a plurality of transducers and associated enclosures are provided with each actuable by a respective digit of the user.

19. An H= device in accordance with any one of the preceding claim further comprising a transmitter or a receiver of spatial position sensing means.

20. An H= device in accordance with any one of the preceding claim further ccuprising pressure feedback mans associated with the or each enclosure to provide when desired increased resistance to deformation.

14.

21. A human cter interface device for transmitting signals between part of a human body and a cter substantially as hereinbefore described.

22. A haptic human cter interface device for transmitting signals between part of a human body and a cter substantially as hereinbefore described and as illustrated in Figures 1 to 4, or Figures 5 and 6 of the accarpanying drawings.

1