APPARATUS AND METHOD FOR PROVIDING RESISTANCE OR FORCE FEEDBACK TO A HUMAN BODY SURFACE

Abstract: At least one bag-like member (1) made at least partially of elastically deformable material such as latex or rubber, for contact with a body surface such as a hand (2) contains a quantity of particulate material such as organic seeds and is connected to gas flow means so that a gaseous medium such as air can be fed controllably into the member (1) to soften the resistance of the member and particulate material to deformation or extracted controllably from the member (1) to harden the resistance of said member and particulate material to deformation to provide a variable desired resistance pressure for the contacting body surface such as a hand (2).

Description: APPARATUS AND METHOD FOR PROVIDING RESISTANCE OR FORCE FEEDBACK TO A HUMAN BODY SURFACE The present invention relates to apparatus and a method for providing resistance or force feedback to a human body surface, particularly, but not exclusively, suitable for human/computer interaction in desktop or immersive virtual reality systems- One of the problems encountered with human/computer interaction in desktop or virtual reality systems is that of imparting a force feedback when, for example, contact with an object is being simulated in the computer or virtual reality environment. Thus if in the virtual reality environment the human operator is attempting to grasp by hand a solid or partially solid object it is desirable to impart to the hand a resistance or force which corresponds to the effect of grasping a solid or partially solid object in reality. It has been proposed to do this by stiffening the resistance of the fingers of a hand to bending so that this resistance to bending conveys an impression of grasping against a solid object. However such proposed techniques are rather complex and do not easily allow variation in force to be fed back to a human hand such as to allow, in a virtual reality environment, the operator to distinguish clearly between grasping a solid object and grasping a partially solid object such as an object having a jelly like consistency. There is thus a need for a generally improved apparatus and method for providing resistance or force feedback to a human body surface, which is capable of providing a simple and relatively inexpensive resistance feedback which is relatively easily variable and controllable. According to one embodiment of the present invention there is provided apparatus for providing resistance or force feedback to a human body surface, including at least one bag-like member made at least partially of elastically deformable material for contact with a body surface, a quantity of particulate material contained in said bag-like member and gas flow means whereby a gaseous medium can be fed controUably into said member to soften the resistance of said member and particulate material to deformation or extracted controUably from said member to harden the resistance of said member and particulate material to deformation so as to provide a variable desired resistance to pressure for the contacting body surface. Preferably the elastically deformable material utilised is plastics, latex or rubber. Conveniently the bag-like member is attached to a computer mouse for contact by a body surface in the form of a human hand. Advantageously the bag-like member is dimensioned to be held in or attached to the palm of a human hand. Preferably the bag-like member is of elongated tubular form for attachment to the inner surface of a human finger to extend there along or for attachment to the inner surfaces of a human finger and thumb to extend there along. Conveniently the particulate material utilised is organic or inorganic, preferably one or more of mustard seeds, sesame seeds, semolina grains, plastics beads or glass beads. Advantageously the gaseous medium utilised is air. Preferably the gas flow means includes a gaseous medium flow pipe opening into the bag-like member for connection to a source of gaseous medium at, above or below atmospheric pressure and a filter located in the bag-like member to prevent particulate material being sucked from the bag-like member when the pressure therein is reduced to less than atmospheric pressure. According to a further aspect to the present invention there is provided a method for providing resistance or force feedback to a human body surface in which at least one bag-like member containing a quantity of particulate material and made at least partially of elastically deformable material is placed in contact with a human body surface to which force feedback is to be provided and a gaseous medium at a pressure at, above or below atmospheric pressure is supplied to or removed from said member to soften or harden the resistance to deformation of said member and thereby provide a variable desired resistance to pressure for the contacting body surface. For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which; Figure one is a diagrammatic view of apparatus according to a first embodiment of the present invention, Figure 2 is a diagrammatic view of apparatus according to a second embodiment of the present invention shown in operative association with a human hand, Figure 3 is a diagrammatic plan view or apparatus according to a third embodiment of the present invention shown in operative association with an open human hand, and Figure 4 is a diagrammatic view of the apparatus of Figure 3 shown in operative association with a closed human hand. Apparatus according to the present invention for providing resistance or force feedback to a human body surface generally includes at least one bag-like member 1 made at least partially of elastically deformable material for contact with a body surface such as the inner surfaces of a hand 2 such as shown in Figures 2, 3 and 4 of the accompanying drawings. The member 1 contains a quantity of particulate material (not shown) and gas flow means including a gas flow pipe 3 whereby a gaseous medium such as air, can be fed controUably into the member 1 to soften the resistance of the member and particulate material to deformation or extracted controUably from the member 1 to harden the resistance of the member and particulate material to deformation so as to provide a variable desired resistance to pressure for the contacting body surface such as the hand 2. The elastically deformable material preferably is plastics, latex or rubber and the particulate material is organic or inorganic preferably one or more of mustard seeds, sesame seeds, semolina grains, plastics beads or glass beads. The bag-like member 1 may be attached to a computer mouse on a table top for contact by a body surface such as a human hand 2. Preferably the member 1 is dimensioned to be held in or attached to the palm of the hand 2 as shown in the embodiment of the invention illustrated in Figure 1. Alternatively the member 1 may be of elongated tubular form such as shown in Figures 2, 3 and 4 of the accompanying drawings for attachment to the inner surface of a human finger 4 to extend there along such as shown in figures 3 and 4 or for attachment to the inner surfaces of a human finger 4 and thumb 5 as shown in Figures 2, 3 and 4 and in particular in Figure 2, to extend there along. The member 1 can be attached to the fingers 4 or thumb 5 in any convenient manner such as by means of elastic rings 6 shown in Figures 2, 3 and 4. The gas flow means includes the gas pipe 3 which opens into the member 1 and is connectable to a source 7 of gaseous medium such as air at, above or below atmospheric pressure. The gas flow means also includes a filter 8 located in the member 1 or in the flow pipe 3 to prevent particulate material being sucked from the member 1 when the pressure there is reduced to less than atmospheric pressure. As shown in Figure 1 the source 7 can include a piston 9 activated by means of a solenoid 10 to displace the piston 9 to extract gaseous medium from the member 1 to increase the stiffness or resistance to deformation thereof. Return of the piston 9 when the solenoid 10 is deactivated returns gaseous medium such as air to the member 1 to reduce the stiffness and resistance to deformation thereof. Thus with this system the gas flow means is gas tight and contains a constant volume of gas which is moved between the member 1 and source 7. Alternatively the gas flow means could be provided by an electric vacuum pump (not shown). The apparatus of the present application is operable such that at least one bag-like member 1 containing a quantity of particulate material and made at least partially of elastically deformable material is placed in contact with a human body surface such as the hand 2 to which force feedback is to be provided and a gaseous medium such as air at a pressure at, above or below atmospheric pressure is supplied to or removed from the member 1 to soften or harden the resistance of the member 1 and thereby provide a variable desired resistance to pressure for the contacting body surface such as the hand 2. Thus in essence the solidity of the bag-like member 1 which is gas tight is varied by withdrawing or introducing a gaseous medium such as air around the particulate material particles. When there is a maximum vacuum in the member 1 the particles of particulate material are packed together very tightly and feel solid. When there is an ample supply of gaseous medium, such as at atmospheric pressure, the particles of particulate material are freeflowing. The amount of gaseous medium such as air in the member 1 can be varied as desired, below, at or above atmospheric pressure to provide a variable consistency and variable resistance to squeezing. In its simplest form, as shown in Figure 1 of the accompanying drawings, the member 1 can be hand held. When force feedback is required air is supplied to the member 1 substantially at atmospheric pressure so that the member 1 can be squeezed easily and the free flowing particles of particulate material therein are displaceable under the pressure of fingers grasping the member 1. When force feedback is required, for example when the hand is positioned correctly for simulating a grasped virtual reality object the air in the member 1 should be evacuated therefrom so that the member 1 will be effectively solid and will be a shape corresponding to the position of the grasping fingers. Thus the member 1 becomes in effect a deformable object which will solidify into a shape defined by the grasping fingers 4 and thumb 5. The force feedback is thus provided by a real object in contrast to earlier proposed forms of forced feedback which use devices to provide force feedback to the fingers by impeding the grasping movement of the fingers to try and simulate the presence of a solid object. By suitably varying the pressure in the member 1 it is possible to allow both solid, partially solid and non-solid objects to be simulated such as for example stone or jelly-like consistency. As shown in Figure 1 of the accompanying drawings the member 1 can be hand held but alternatively as shown in the embodiment of Figures 2, 3 and 4 the member 1 can be strapped to the hand or even as previously described used like a computer mouse on a table top. To enable three dimensional space positioning of the member 1 to be sensed a position tracker, for example magnetic or optical, may be located inside or attached to the member 1. A pressure-sensing unit inside the member 1 could be used to sense finger closure, or the apparatus of the present application may be worn over a finger tracking "glove" of a type generally known. The member 1 preferably is fully filled with the particulate material but not so much that the member 1 is distorted by the particulate material. In the embodiment of Figures 2, 3 and 4 the members 1 at atmospheric pressure will bend freely as the finger 4 or thumb 5 bends. When the air is removed from the members 1 and a vacuum is created therein the members 1 will solidify in whatever shape they are bent to thus preventing, or at least strongly resisting further flexion of the fingers 4 and thumb 5. Varying the amount of air removed from the members 1 will vary the resistance and will allow simulation of objects with varying degrees of solidity. A single member 1 may be attached to the first finger 4 and thumb 5 as shown in Figure 2 so that the member 1 runs close to the inner surfaces of that finger and thumb. The thumb attachment may be a fixed position but the finger attachment or ring 6 may slide up and down the member 1 in order to fit different sized fingers and hands. It is necessary to design the attachment and positioning of the member 1 in Figures 2, 3 and 4 so that when the finger and thumb bend the member 1 bends in an even manner and pressure is spread along the member 1 rather than being concentrated at one point such as the attachment points. For the same reason it is advisable that the member 1 be fully filled with particulate material but not so much that the member 1 is distorted. More than one such member 1 can be provided, one for each finger 4 and thumb 5 as shown in Figures 3 and 4. These members 1 are located on the inner surfaces, that is the palm side, of the hand 2 as illustrated.

Claims: WHAT WE CLAIM IS; 1 ' apparatus for providing resistance or force feedback to a human body surface, including at least one bag-like member made at least partially of elastically deformable material for contact with a body surface, a quantity of particulate material contained in said bag-like member and gas flow means whereby a gaseous medium can be fed controUably into said member to soften the resistance of said member and particulate material to deformation or extracted controUably from said member to harden resistance of said member and particulate material to deformation so as to provide a variable desired resistance to pressure for the contacting body surface. 2. Apparatus according to claim 1, wherein the elastically deformable material utilised is plastics, latex or rubber. 3. Apparatus according to claim 1 or claim 2, wherein the bag-like member is attached to a computer mouse for contact by a body surface in the form of a human hand. 4. Apparatus according to claim 1 or claim 2, wherein the bag-like member is dimensioned to be held in or attached to the palm of the human hand. 5. Apparatus according to claim 1 or claim 2, wherein the bag-like member is of elongated tubular form for attachment to the inner surface of a human finger to extend there along or for attachment to the inner surfaces of a human finger and thumb to extend there along. 6. Apparatus according to any one of claims of 1 to 5, wherein the particulate material utilised is organic or inorganic. 7. Apparatus according to claim 6, wherein the particulate material utilised is one or more of mustard seeds, sesame seeds, semolina grains, plastics beads or glass beads. 8. Apparatus according to any one of claims 1 to 7, wherein the gaseous medium utilised is air. 9. Apparatus according to any one of claims 1 to 8, wherein the gas flow means includes a gaseous medium flow pipe opening into the bag-like member for connection to a source of gaseous medium at, above or below atmospheric pressure and a filter located in the bag-like member or flow pipe to prevent particulate material being sucked from the bag-like member when the pressure there is reduced to less than atmospheric pressure. 10. Apparatus for providing resistance or force feedback to a human body surface, substantially as herein before described and as illustrated in Figure 1, Figure 2 or Figures 3 and 4 of the accompanying drawings. 11. A method for providing resistance or force feedback to a human body surface in which at least one bag-like member containing a quantity of particulate material and made at least partially of elastically deformable material is placed in contact with a human body surface to which force feedback is to be provided and a gaseous medium at a pressure at, above or below atmospheric pressure is supplied to or removed from said member to soften or harden the resistance to deformation of said member and thereby provide a variable desired resistance to pressure for the contacting body surface. 12. A method for providing resistance or force feedback to a human body surface substantially as herein before described with reference to Figure 1, Figure 2 or Figures 3 and 4 of the accompanying drawings.

Inventors: CARR KAREN, CARR, KAREN
Applicants: BRITISH AEROSPACE, CARR KAREN, BRITISH AEROSPACE PUBLIC LIMITED COMPANY, CARR, KAREN
Application year: 1996
Main classification: G06F3
IPC codes: G06F3