EP0652503B1 - Manual control device with tactile feedback and/or feedback of the feeling of the movement - Google Patents

Abstract

It is proposed to drive a real or virtual slave system with p degrees of freedom by means of a manual control device comprising a grip (10) formed of an active component (12) and of one or two information-return components (14). A displacement of speed sensor (24) can be mounted in the active component (12) in order to generate signals used in driving the slave system. Actuators mounted for example in a support linked to the grip (10) by a flexible cord (22) receive information from the slave system and transform it into a torque. This torque is transmitted to the information-return component (14), for example by cables (30, 34), so that a force representative of the information originating from the slave system is applied to the hand of the operator. <IMAGE>

Description

The invention relates to a control member designed to be actuated by the hand of a human operator, so as to control a real or virtual slave system, by providing the operator with tactile and / or kinesthetic feedback.

A control device in accordance with the invention can be used to control any real or virtual slave system, that is to say in particular in teleoperation, in simulators, in CAD (Computer Aided Design) and CAD / CAM systems. (Computer Aided Design and Manufacturing), etc., this slave system generally having six degrees of freedom.

The manual control devices existing to date include data gloves, handles and pens, master arms and joysticks.

Data gloves (see for example document WO-A-91 11775) are gloves fitted with devices for measuring their absolute position in space and with devices for measuring the relative position of the fingers. Their applications mainly concern the field of simulation and that of human-machine interfaces. They may be able to restore tactile or kinesthetic information by the use of exoskeletons or the external mobilization of the joints of the operator's hand.

The main advantage of data gloves is that they adapt well to simulation applications. They do, however, many disadvantages. These disadvantages include, in particular, insufficient reliability, a high number of degrees of freedom, delicate positioning on the operator's hand, different calibration for each user and, in certain cases, each time the glove is put on, significant congestion of kinesthetic feedback systems and the very restrictive and uncomfortable nature of these systems.

Handles and pens have the same type of devices as data gloves for measuring their absolute position in space. They are used to define positions or to designate items in simulation systems or in CAD and CAD / CAM systems and they perform functions equivalent to those of computer mice. They can have up to six degrees of freedom. On the other hand, existing handles and pens are generally not equipped with a tactile or kinesthetic feedback system.

In Robert Stone's article "Virtual reality and telepresence" published in Robotica (1992) volume 10, pages 461 to 467, it is proposed to control a virtual system by means of a handle with six degrees of freedom equipped with three pads inflatable intended to restore to the operator a tactile impression of contact with a virtual object. The feedback is however very limited since each pad only has one degree of freedom. It is therefore a rough approximation which cannot restore to the operator all the degrees of freedom of a slave system with six degrees of freedom, and in particular the degrees of freedom of orientation.

Document US-A-4,795,296 also describes a handle having a return piece of information from the slave gripping system. This part is a trigger which has two degrees of freedom, so as to restore position and effort information to the operator. The trigger also constitutes, with a vis-à-vis guard, a control member by means of which the operator actuates a two-jaw collet. The information returned to the operator relates to the clamping force and the lateral displacement of the clamp when it is centered on the object to be grasped. The information concerning the lateral movement of the gripper is not directly linked to a movement controlled by the operator. Consequently, this feedback is very difficult to assess. In addition, a failure of the feedback system may interfere with the control of the slave system, and even prevent this control.

The master arms have been designed and developed for remote handling applications, in particular in master / slave remote manipulators with or without force feedback. They can be active or passive. In the latter case, these include learning puppets for industrial manipulators and teleoperators.

The main advantage of the master arms lies in their good adaptation to remote handling. However, they are expensive, heavy and bulky. In addition, when they are equipped with kinesthetic feedback, the compromises between the useful volume and the quality of this feedback are very bad.

Finally, the brush handles (see in particular the document EP-A-0 384 806) are devices for measuring displacements or forces which are integrated into work stations or button boxes.

The advantages of broom handles are low cost and high performance when the applications are simple and do not exceed three degrees of freedom. However, they do not include a feedback device. In addition, they have a generally limited useful volume, a number of degrees of freedom rarely exceeding three and they must necessarily be positioned on fixed supports.

The subject of the invention is precisely a control device with feedback of a new type, capable of being actuated by an operator so as to control a real or virtual slave system in a simple, inexpensive and easy to set up manner. work, and making it possible to obtain a satisfactory compromise between the useful volume and the quality of the feedback, for a number of degrees of freedom generally equal to six.

Another subject of the invention is a feedback control device, in which an interruption or failure of the feedback system does not prevent the slave system from being controlled.

• une poignée incluant une surface extérieure principalement formée d'une pièce active et d'au moins une pièce de retour d'information distincte de la pièce active et mobile par rapport à celle-ci ;
• des moyens de commande de mouvements du système esclave, en réponse à une action sur la pièce active de la poignée, indépendamment de la position de la pièce de retour d'information par rapport à cette pièce active ; et
• des moyens de commande des mouvements de chaque pièce de retour d'information par rapport à la pièce active, en réponse à des signaux de retour d'information en provenance du système esclave.

According to the invention, this result is obtained by means of a manual control member of a slave system, comprising:

• a handle including an outer surface mainly formed by an active part and at least one feedback part distinct from the active part and movable with respect thereto;
• means for controlling movements of the slave system, in response to an action on the active part of the handle, independently of the position of the piece of feedback in relation to this active part; and
• means for controlling the movements of each piece of feedback relative to the active piece, in response to feedback signals from the slave system.

In a control member thus designed, the operator's hand is in permanent contact with the feedback piece forming the handle, so that this hand receives a force whose direction and amplitude are representative of a real or virtual force applied to the slave system. Advantageously, the force exerted on the operator's hand by the feedback piece is then proportional to this resistant force.

Preferably, the slave system has p degrees of freedom, the handle has q pieces of feedback, and each piece of feedback has r degrees of freedom relative to the active piece, with r> 2 and qxr> p. Advantageously, the number of pieces of feedback is at most equal to two.

In a preferred embodiment of the invention, the manual control member further comprises a support independent of the movement control means of the slave system, and the movement control means of each piece of feedback include at minus an actuator mounted in this support and means for transmitting movements, connecting the actuator to the feedback piece.

In this case, the active part of the handle may be either only connected to the support by a flexible cord in which the movement transmission means pass, or mechanically connected to the support by an articulated arm, along which the movement transmission means can travel.

The movement transmission means preferably comprise at least two cables capable of sliding in sheaths. A first of these cables connects a first actuator to the feedback piece through a movement reversal means and at least a second of these cables directly connects a second actuator to the feedback piece. The slave system having p degrees of freedom, the control member comprises p second cables and p second actuators. It should be noted that, as a variant, the actuator or actuators can also be integrated in the handle.

When the handle comprises a single piece of feedback, this piece can form a single end part or a central part of the handle. It can also include several protuberances housed in openings formed in the active part.

In order to have the assurance that the operator keeps his hand on the handle feedback piece when effectively controlling the slave system, the feedback piece preferably carries at least one control button for coupling the control unit to the slave system.

• les figures 1A à 1D sont des vues de face illustrant quatre formes de réalisation possibles de la poignée d'un organe de commande manuelle conforme à l'invention ;
• la figure 2 est une vue en perspective illustrant schématiquement un organe de commande manuelle conforme à l'invention, comportant la poignée représentée sur la figure 1A ;
• la figure 3 est une vue à plus grande échelle représentant, en coupe longitudinale partielle, la poignée et la partie attenante du cordon de l'organe de commande manuelle illustré sur la figure 2 ; et
• la figure 4 illustre une autre forme de réalisation de l'invention, dans laquelle la poignée est reliée au support par un bras articulé.

We will now describe, by way of nonlimiting examples, various embodiments of the invention, with reference to the accompanying drawings, in which:

• Figures 1A to 1D are front views illustrating four possible embodiments of the handle of a manual control member according to the invention;
• Figure 2 is a perspective view schematically illustrating a manual control member according to the invention, comprising the handle shown in Figure 1A;
• Figure 3 is an enlarged view showing, in partial longitudinal section, the handle and the adjoining part of the cord of the manual control member illustrated in Figure 2; and
• FIG. 4 illustrates another embodiment of the invention, in which the handle is connected to the support by an articulated arm.

The manual control member according to the invention mainly comprises a handle capable of being grasped by the hand of a human operator. According to the invention, this handle comprises an active part on which the operator's hand acts, as well as one or two pieces of tactile and / or kinesthetic feedback. The handle has six degrees of freedom.

In the figures, the handle is generally designated by the reference 10.

In the embodiment of FIG. 1A, the handle 10 comprises an active part 12 and a part 14 for feedback, arranged side by side, the part 14 for feedback being movable relative to the active part 12 More precisely, the active part 12 of the handle constitutes the essential of the latter, with the exception of its upper end which is formed by the part 14 for feedback.

In the example shown, the part 14 for feedback has imprints 16 intended to receive the thumb and forefinger of the operator's hand, while the other fingers are received on imprints 18 formed on the part active 12. Being given that the part 14 for feedback can move relative to the active part 18, the continuity of the exterior surface of the handle 10 between these two parts is ensured by a flexible ring 19 (FIG. 3).

In the embodiment illustrated in FIG. 1B, the handle 10 comprises a piece of feedback 14 inserted movably between two parts of an active part 12. The active part 12 then forms the two ends of the handle 10 while the central part of this handle is formed by the part 14 for feedback. In this case, the piece 14 of feedback returns for example an imprint 16 intended to receive the ring finger of the hand of the operator while the other fingers of the operator are received in imprints 18 formed on the two parts of the active part 12. Two flexible rings (not shown) are then provided to ensure continuity between the part 14 of feedback and the two parts of the active part 12.

FIG. 1C illustrates a third embodiment in which the handle 10 is completely formed by an active part 12 pierced with one or more openings 13. In these openings are housed protuberances of a single piece 14 of feedback, movably mounted inside the active part 12. The shape, the number and the locations of the openings 13 in which the protrusions of the piece of feedback 14 are housed can be any. They correspond, for example, but not exclusively, to the ends of some of the operator's fingers.

Finally, in the fourth embodiment illustrated in FIG. 1D, the handle 10 is formed mainly from an active part 12, except in its upper part, as in the embodiment of FIG. 1A. However, instead of being formed by a single piece of feedback, the upper end of the handle in this case comprises two different feedback pieces, designated by the references 14a and 14b in FIG. 1D . Each of these feedback pieces is then mobilized independently of the other with respect to the active piece 12.

More specifically, the two pieces of feedback 14a and 14b are arranged symmetrically with respect to the medium plane of the handle 10 and each having four degrees of freedom relative to the active part 12 when the slave system has six degrees of freedom. Thus, each part 14a and 14b has three degrees of freedom of translation along the transverse axes OX, longitudinal OY and along the axis OZ orthogonal to the preceding ones, and a degree of freedom of rotation around the transverse axis OX. The degrees of freedom of rotation around the axes OY and OZ are translated by relative translations of the parts 14a and 14b along the axes OZ and OY, respectively.

A manual control member according to a first embodiment of the invention, equipped with the handle 10 of FIG. 1A, will now be described in more detail, with reference to FIGS. 2 and 3.

As illustrated in FIG. 2, the active part of the handle 10 is connected, by its lower end, to a support 20, intended in particular to serve as a receptacle for it. This connection is ensured by a flexible cord 22, one end of which is fixed to the lower end of the handle 10 and the opposite end of which is fixed to the support 20.

The handle 10 thus has six degrees of freedom which allow it to control a system slave (not shown) with six degrees of freedom. This slave system can be real or virtual. Thus and only by way of example, it can be either an articulated arm of a manipulator or a simulator or a CAD or CAD / CAM system. The support 20 is connected to the slave system by appropriate wiring (not shown).

As illustrated more precisely in FIG. 3, a speed and / or displacement sensor 24 is fixedly mounted inside the active part 12 of the handle 10. This sensor 24 makes it possible to measure the speed and / or the movement of the handle 10 when it is placed in the hand of the operator. The measurements carried out are transformed into electrical signals which are conveyed to the support 20 by an electrical conductor 26 placed in the flexible cord 22. These signals are then transmitted to the slave system for example by means of another electrical conductor, so as to control this slave system in speed and / or in displacement, depending on the nature of the measurements made by sensor 24.

According to the invention, the manual control member illustrated in FIGS. 2 and 3 is also provided with means making it possible to control a movement of the part 14 for feedback relative to the active part 12, in response to a feedback signal from the slave system. This feedback signal can be very diverse in nature depending on the type of slave system controlled and the application envisaged.

It may in particular be a force feedback allowing the operator's hand to transmit a force signal proportional to a real or virtual resistance force supported by the slave system. In the case where the slave system is constituted by a remote manipulator slave arm, this signal can be representative of the coming into abutment of the slave arm or of a part supported by this arm against an obstacle and proportional to the reaction force opposed by this obstacle.

The feedback signal can also be representative of the approach to a prohibited area by a real or virtual slave system.

In the embodiment illustrated in FIGS. 2 and 3, the means making it possible to control the movement of the piece of information feedback 14 comprise p + 1 actuators 28 (FIG. 2) which are housed in the support 20. p represents here the number of degrees of freedom available to the slave system, that is to say six in the embodiment illustrated in the figures. In this example, the control means therefore comprise seven actuators 28. These actuators can be of different types. Thus and only by way of example, they may be electrical actuators such as small electromagnets, pneumatic actuators such as cylinders, etc.

Each of the actuators 28 is connected to the slave system for example by an electrical conductor so as to be able to receive a feedback signal representative of a degree of freedom of the latter. This signal is transformed by each of the actuators 28 into a torque which is transmitted to the part 14 for feedback by means of motion transmission means traveling mainly inside the flexible cord 22.

More specifically, p actuators 28 (six in the example described) act on the part 14 for feedback of the handle 10, through motion transmission means, according to the p degrees of freedom available to this part 14 compared to the active part 12. The last actuator 28 acts on the part 14 for feedback in order to oppose the actions exerted by the other actuators, to keep this part 14 immobile with respect to the active part 12 when no return d information does not take place. This arrangement is explained by the structure of the motion transmission means which are interposed between the actuators 28 and the part 14 for feedback in the embodiment shown in FIGS. 2 and 3.

In fact, in this described embodiment, the means for transmitting movement between the actuators 28 and the part 14 for feedback are constituted by sliding cables which can only exert tensile forces.

More specifically, each of the six actuators corresponding to the six degrees of freedom of the slave system and of the piece 14 of feedback returns acts on a cable 30 capable of sliding in a sheath 32 inside the flexible cord 22 and its opposite end is fixed to the part 14 for feedback in a triangular arrangement similar to that of a so-called Steward platform. In other words, the six cables 30 are fixed two by two to the three vertices of a triangle, on the piece 14 of feedback.

In order to oppose the tensile force exerted on the piece 14 of feedback by the cables 30, the remaining actuator 28 acts on a seventh cable 34, which also slides in a sheath 36 inside the flexible cord 22, but the opposite end of which acts on the piece 14 of feedback by means of a movement reversal mechanism. This mechanism transforms the tensile force exerted by the cable 34 into a compressive force applied to the part 14. It acts on the latter at the center of the triangle at the vertices of which the cables 30 are hung.

In the embodiment illustrated in FIG. 3, the movement reversing mechanism comprises a lever 38 and a push rod 40. The lever 38 is pivotally mounted, in its central part, on the active part 12 and the cable 34 is hung at one of its ends. The opposite end of the lever 38 is supported on one end of the push rod 40. The opposite end of this rod 40 is supported on the piece 14 of feedback, at the center of the triangle whose vertices serve to hanging cables 30.

The arrangement which has just been described makes it possible to apply to the hand of the operator a force whose direction and intensity are representative of information coming from the slave system and taking into account all the degrees of freedom whose has this system.

The means used to control a movement of the piece or pieces 14 of feedback can be different from those which have just been described. Thus, the actuators can be placed directly inside the handle 10, so as to act individually on one of the two pieces of feedback 14a and 14b, in the embodiment of the handle illustrated in the Figure 1D. In this case, the support 20 and the cord 22 can optionally be removed.

Advantageously, and as illustrated in FIG. 2, the part 14 for feedback is provided on its outer surface with one or two buttons 42 used to control the coupling of the control member to the slave system. In the embodiment of the handle 10 illustrated in FIG. 1A, the buttons 42 can in particular be placed in each of the indentations 16 formed on the piece 14 of feedback to receive the thumb and forefinger of the operator's hand.

Because the actuation of the buttons 42 conditions the coupling of the control member to the slave system, it is certain that the operator's hand will be in contact with the part 14 of feedback if an effort representative of such feedback from the master arm is applied to this part 14.

As illustrated schematically in Figure 2, the handle 10 can also be equipped with various other buttons such as an emergency stop button 44, as well as one or more displays 46 on which may appear various information such as deviations, states of forces and moments, etc.

The support 20 can also be provided with one or more control buttons 48 and one or more displays 50 as also illustrated in FIG. 2.

FIG. 4 very schematically illustrates another embodiment of the invention in which, instead of being connected to the support 20 by a flexible cord, the active part 12 of the handle 10 is fixed to one end of an articulated arm 52, the opposite end of which is mounted on the support 20.

In this case, the actuators 28 can remain associated with the support 20. They act on the part 14 for feedback of the handle by a transmission system such as a sliding cable system similar to that which has been described previously with reference to FIG. 3, this cable system then being guided on the articulated arm 52.

The actuators can also be distributed along the structure of the articulated arm, for example in the last segment of the arm. The latter is then balanced accordingly, to compensate for the weight of the actuators.

The structure of the articulated arm 52 can be adapted to each of the slave overseeds that it is desired to control. For this, modular segments and joints can in particular be used, which can be assembled on demand with the handle 10.

The control of the movements of the slave system can be carried out either by means of mounted sensors, as in the embodiment described above with reference to FIGS. 2 and 3, or by means of instrumentation associated with each of the articulations of the articulated arm 52.

In this arrangement, the information feedback means remain completely separate from the slave system control means. These feedback means can therefore be taken out of service, voluntarily or following a physical failure (cable break, amplifier failure) or computer failure, without affecting the control of the slave system.

Claims (16)

1. Manual control member of a slave system incorporating:

   - a handle (10) including an outer surface mainly formed by an active part (12) and at least one information return part (14) separate from the active part and mobile with respect thereto,

   - means (24) for controlling movements of the slave system in response to an action on the active part (12) of the handle (10), independently of the position of the information return part with respect to said active part and

   - means (28) for controlling movements of each information return part (14) relative to the active part (12), in response to information return signals from the slave system.
2. Manual control member according to claim 1, wherein the slave system has p degrees of freedom, the handle (10) has q information return parts (14) and each information return part has r degrees of freedom with respect to the active part, with r > 2 and q x r >p.
3. Manual control member according to claim 2, wherein the number q of information return parts (14) is at the most two.
4. Manual control member according to any one of the preceding claims, wherein there is also a support (20) independent of the movement control means (24) of the slave system and wherein the movement control means of each information return part (14) incorporate at least one actuator (28) mounted in said support (20) and movement transmission means (30, 34) connecting the actuator (28) to the information return part (14).
5. Manual control member according to claim 4, wherein the active part (12) of the handle (10) is connected to the support (20) by a flexible cord (22) in which pass the movement transmission means (30, 34).
6. Manual control member according to claim 4, wherein the active part (12) of the handle is mechanically connected to the support (20) by an articulated arm (52).
7. Control member according to any one of the claims 4 to 6, wherein the movement transmission means incorporate at least two cables (34) able to slide in sheaths (32, 36), a first (34) of said cables connecting a first actuator (28) to each information return part (14) through a movement inversion means (38, 40) and at least one second (30) of said cables directly connecting a second actuator (28) to each information return part.
8. Control member according to claims 2 and 7 combined, comprising p second cables (30) and p second actuators.
9. Control member according to any one of the claims 1 to 3, wherein the movement control means of each information return part (14) comprise at least one actuator mounted in the handle (10).
10. Control member according to any one of the preceding claims, wherein the handle (10) comprises a single information return part (14).
11. Control member according to claim 10, wherein the information return part (14) forms an end portion of the handle (10).
12. Control member according to claim 10, wherein the information return part (14) forms a central portion of the handle (10) interposed between two portions of the active part (12).
13. Control member according to claim 10, wherein the information return part (14) has several protuberances located in openings (13) formed in the active part (12).
14. Control member according to any one of the claims 1 to 9, wherein the handle (10) comprises two information return parts (14a, 14b).
15. Control member according to any one of the preceding claims, wherein the information return part (14) carries at least one button (42) for controlling the coupling of the control member to the slave system.
16. Control member according to any one of the preceding claims, wherein the handle (10) carries at least one display.

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