Method and system for controlling slave device at physical movement limits of slave device in surgical master-slave teleoperation robotic system

Abstract

A method of controlling a slave device of a robotic system for medical or surgical teleoperation is described, wherein the robotic system comprises at least one handheld master device adapted to be moved by an operator, and at least one slave device adapted to be controlled by the at least one master device. The method controls the movement of the at least one slave device such that: a) if a nominal target pose (180) having a respective orientation in a rotation space of the at least one slave device (170) is outside a working area (174) belonging to the rotation space of the at least one slave device; if a nominal target pose (180) and a modified target pose (184) defined such that it is inside a working area (174) of the at least one slave device are inside the departure area (192), controlling an orientation of the at least one slave device (170) to converge to the modified target pose (184), and if the nominal target pose (180) and the modified target pose (184) defined such that it is inside the working area (174) of the at least one slave device are inside the departure area (192); b) if at least one of the nominal target pose (180) and the modified target pose (184) is outside the start area (192), preventing rotational movement of the at least one slave device until both the nominal target pose (180) and the modified target pose (184) enter the reentry area (196); c) when both the nominal target pose (180) and the modified target pose (184) return to the reentry area (196) after leaving the working area, controlling the orientation of the at least one slave device to converge to the modified target pose (184) by the slowed teleoperation phase, and when the orientation of the at least one slave device converges to the modified target pose (184), controlling the orientation of the at least one slave device to converge to the modified target pose (184) by the slowed teleoperation phase. The slowed teleoperation phase ends.

Description

Technical Field

[0001] The present invention relates to a method and system for controlling a robotic system for medical or surgical teleoperation.

[0002] In particular, the present invention relates to a method of controlling a slave device, which is controlled by a master device that can be moved by an operator in a robotic system for medical or surgical teleoperation, close to the physical limits of the movement of the slave device, especially with regard to rotational degrees of freedom, and a related robotic system. Background Art

[0003] In the field of master-slave robot systems for medical or surgical teleoperation, it is generally known that the master device has an appendage that is mechanically constrained to the operating console. Typically, this appendage includes an actuating motor that actuates the master device to limit its movement under certain conditions.

[0004] The operating console usually further comprises a foot switch for transmitting control signals to the slave devices in turn. Alternatively, or in addition to the foot switch, a switch may also be included on the main body of the master device itself.

[0005] A master device for medical or surgical teleoperation is also proposed, which is mechanically constrained directly to one or more slave robotic arms to move the one or more slave robotic arms by means of master-slave actuation kinematics.

[0006] It is also known for a master device used for medical or surgical teleoperation to be mechanically constrained to a console by means of a universal suspension ("gimbal").

[0007] In addition, it is also known that robotic systems for medical or surgical teleoperation have a main device that is not mechanically constrained to the operating console of the robotic system (also called: "mechanically ungrounded", "mechanically unconstrained", "mechanically ungrounded"), i.e., for example, the type shown in WO-2019-020407, WO-2019-020408, WO-2019-020409, WO-2021-161158, WO-2021-161185 and WO-2021-161177 in the name of the applicant.

[0008] Another class of masters is the non-actuated or "ungrounded" type, i.e., there is no feedback system from the slave that can physically limit its maneuverability. Both mechanically unconstrained type masters and masters constrained to an operator console can belong to this class, for example including gimbaled supports and stabilizing joints ("gimbals"). In "ungrounded" type masters without force feedback, and in unilateral teleoperation, there is the question of what happens when the corresponding nominal target pose to which the master is mapped is unreachable by the slave, for example because it is outside the allowed workspace of the slave.

[0009] In order to maintain a high degree of teleoperation usability and preserve intuitive operator behavior, a need arises to provide modified and improved control methods and algorithms when the slave device is located close to the limits of the allowed workspace and / or when the nominal target pose is outside of the above-mentioned workspace of the slave device.

[0010] For example, unilateral teleoperation is given between a symmetrical N-folded master and a slave (microsurgical instrument), with degrees of freedom of a translational nature (usually in 3 mutually orthogonal directions), degrees of freedom of a rotational nature (whose spatial posture can usually be described by 3 consecutive rotations) and possible additional degrees describing the state of the microsurgical device, such as "closed" (or grasping).

[0011] Assume that a symmetric N-folded master has at least the same number of degrees of freedom as the controlled device. In this case, unilateral teleoperation can be considered as an information flow between the master and the slave (e.g. Figure 4 ).

[0012] Since the master is unconstrained, there is no a priori fixed mapping between the positions of the master and slaves. Such a mapping is created at a specific moment, such as entering teleoperation, where the movement of the slave is "coupled" with the movement of the master.

[0013] In the context of microsurgery, particularly involving rotational degrees of freedom, an unconstrained master includes the possibility to uniquely relate a priori the orientation of the master to the orientation of the slave. This mapping is typically 1-1.

[0014] However, any rotational misalignment between the master and the unrecoverable slave is a cause of degradation in the robotic system performance.

[0015] In this regard, the existence of limits, involving for example the rotational degrees of freedom, requires special management of teleoperation close to these limits.

[0016] For example, prior art document EP 3459429 A1 shows a robotic system for laparoscopic surgical teleoperation having a robotic surgical probe insertion control system configured to allow simultaneous insertion of all robotic probes in a coordinated manner based on a single command from a user.

[0017] Therefore, in master-slave robotic systems with constrained and unconstrained masters, there is a felt need to define appropriate teleoperation behavior when the slave is located close to these limits, as well as to optimize the user experience during teleoperation paradigm changes.

[0018] In the considered technical field, the known solutions do not satisfactorily solve the above-mentioned problems and disadvantages.

[0019] Therefore, in the considered technical field, there is an urgent need to control the slave movement of slave devices according to the master device, according to the plan and based on the control algorithm, so as to solve or at least alleviate the above-mentioned problems and shortcomings.

[0020] In particular, a need is felt to be able to ensure that the surgeon's grip on at least one master control device, of a type not constrained to the console and / or of a type without force feedback, allows an intuitive and smooth teleoperation session, even approaching the limits of the rotational workspace of slave devices, such as the physical limits of the rotational joints of slave surgical instruments and / or slave robotic manipulators.

[0021] In more detail, teleoperation needs to continue uninterrupted when the current pose of the slave device causes one or more slave rotational joints to approach their physical limits, even if the pose commanded by the unconstrained master device and / or without force feedback would force it beyond the physical limits. Summary of the invention

[0022] The object of the present invention is to provide a method for controlling a slave device controlled by an unconstrained master device capable of being moved by an operator, close to the physical limits of movement of the slave device, which allows to at least partially eliminate the above-mentioned disadvantages complained of with reference to the prior art and responds to the above-mentioned needs that are particularly felt in the technical field under consideration.

[0023] This object is achieved by a method according to claim 1 .

[0024] Further embodiments of the method are defined by claims 2-26.

[0025] The present invention also aims to provide a robotic system for medical or surgical teleoperation, which is configured to be controlled by the above method. This object is achieved by a system according to claim 27.

[0026] Further embodiments of the system are defined by claims 28-51. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Other characteristics and advantages of the method according to the invention will become apparent from the following description of a preferred embodiment given by way of non-limiting indication with reference to the accompanying drawings, in which:

[0028] - Figure 1 A master-slave robot system for medical or surgical teleoperation according to an embodiment of the present invention is shown;

[0029] - Figure 2 and Figure 3 The embodiments of the present invention are respectively shown in more detail. Figure 1 The robot system includes a master device and a slave device;

[0030] - Figure 4 The information flow between the master and slave devices in a master-slave robot system is shown in a diagrammatic and simplified manner;

[0031] - Figure 5-12 , 6a, 7a and 9a illustrate, with the aid of schematic diagrams, operating conditions which can occur during the implementation of the method according to the invention, which are relevant for the purpose of describing the method according to the invention.

[0032] It should be noted that in the drawings, equal or similar elements will be indicated by the same numerical or letter references. DETAILED DESCRIPTION

[0033] Reference Figure 1-12 , 6a, 7a and 9a, a method of controlling a slave device 170 of a robotic system 100 for medical or surgical teleoperation (hereinafter also referred to as a robotic system or simply a system) is now described.

[0034] The robotic system 100 includes at least one handheld host device 110 and is adapted to be moved by an operator 150 .

[0035] The robotic system 100 further comprises at least one slave robotic assembly 120 including at least one slave device 170 (or slave surgical instrument 170 ) adapted to be controlled by the at least one master device 110 .

[0036] The slave robotic assembly 120 may further include at least one non-sterile manipulator 130 including one or more electric actuators and adapted to be controlled by the at least one master device 110 , wherein the at least one slave device 170 is operable and detachably connectable to the at least one manipulator 130 .

[0037] Preferably, the at least one device 170 is sterile and connected to the manipulator 130 via an intervening sterile barrier (not shown).

[0038] The at least one slave device 170 may include a distal articulated end portion that is moved by a tendon or an actuation cable, and the distal articulated end portion is operably capable of connecting to an electric actuator of the at least one non-sterile manipulator 130 of the slave robotic assembly 120.

[0039] According to an embodiment, the slave robotic assembly 120 includes two slave devices 170 (or slave surgical instruments 170 ) working in the same shared workspace.

[0040] The at least one master device 110 is preferably an "ungrounded" type master device without force feedback for unilateral teleoperation. Thus, for example, the at least one master device 110 can be an ungrounded type master device mechanically constrained to the operator console 140 for unilateral teleoperation while having no force feedback.

[0041] Alternatively, the at least one master device 110 may be a master device of a type that is not mechanically constrained to the operator console 140, such as, for example Figure 2 As shown in .

[0042] Reference Figure 1 , the operating console 140 may include a tracking field generator 142 , such as an electromagnetic field transmitter, to be able to detect the position and / or orientation of the at least one master device 110 within a generated tracking field 144 .

[0043] For example, the origin of the master global reference frame (MFO, “master frame origin”) may coincide with the location of the tracking field generator 142 .

[0044] Reference is again made to the method according to the invention and also to Figure 5-12 , 6a, 7a and 9a, the method comprises the step of defining a nominal target pose 180 having a corresponding orientation in the rotational space of the at least one slave device 170 .

[0045] The at least one slave device 170 has a corresponding working area 174 belonging to the rotation space of the at least one slave device 170 .

[0046] The method further comprises the step of defining a modified target pose ("proxy") 184 in the rotational space of the at least one slave device 170, the modified target pose being defined such that it is within the working area 174 of the at least one slave device 170 (see e.g. Figure 6 , 6a , 7, 7a, 9 and 9a).

[0047] The method further includes defining a departure area 192 centered around the current pose of the at least one slave device 170 (see, e.g. Figure 6 , 6a , 7, 7a, 8 and 11) and reentry region 196 (see e.g. Figure 8 , 9 , 9a, 10 and 12).

[0048] The departure area 192 is a first subspace of the rotation space of the at least one slave device 170 .

[0049] The re-entry region 196 is a second subspace of the rotation space of the at least one slave device 170 .

[0050] Therefore, the departure area 192 centered about the current pose of the at least one slave device is a rotational attractor space (e.g., roll-pitch-yaw) that is defined to evaluate the removal of the nominal target pose 180 from the working area 174 in the step of causing the nominal target pose 180 to leave / remove from the working area 174.

[0051] The reentry region 196 centered on the current posture of the at least one slave device is instead a rotational attractor space (e.g., roll-pitch-yaw) that is defined for the approach of the nominal target posture 180 to the working area 174 in the step of bringing the nominal target posture 180 closer to the working area after the nominal target posture 180 leaves the working area.

[0052] The method further comprises the step of controlling the movement of the at least one slave device 170 such that:

[0053] a) If the nominal target pose 180 is outside the working area 174, and the nominal target pose 180 and the modified target pose 184 are inside the departure area 192 (e.g. Figure 6 and Figure 6a ), then controlling the orientation of at least one slave device 170 to converge to a modified target pose 184 (such as Figure 6 and Figure 6a , where arrow A1 represents a convergent movement of at least one slave device 170 to a modified target pose);

[0054] -b) if at least one of the nominal target pose 180 and the modified target pose 184 is outside the departure area 192 (e.g. Figure 7 and Figure 7a, wherein the nominal target pose 180 is outside the departure region 192), then the rotational movement of the at least one slave device 170 is prevented until both the nominal target pose 180 and the modified target pose 184 enter the reentry region 196 (e.g., Fig. 9 and Figure 9a )

[0055] -c) when both the nominal target pose 180 and the modified target pose 184 re-enter the re-entry region 196 after leaving the working region 174 (e.g., Fig. 9 and Figure 9a ), through a slowed teleoperation phase, controlling the orientation of at least one slave device 170 to converge to a modified target pose 184 (such as Fig. 9 and Figure 9a , where arrow A1 represents a converging movement of at least one slave device 170 to a modified target pose).

[0056] "Slowed down teleoperation" means teleoperation in which the dynamics of the slave device are slowed down, ie the speed and rotational acceleration of the slave device are scaled.

[0057] Therefore, it is important to note that the slowing down envisioned in “slowed down teleoperation” does not refer to a scaling of the slave device position.

[0058] The slowed teleoperation phase ends when the orientation of the at least one slave device 170 converges to the modified target pose 184 (e.g., Fig.10 As shown in the diagram, Fig. 9 and Figure 9a , only the at least one slave device 170 is shown to completely overlap with the modified target position 184).

[0059] According to an embodiment of the method, the controlling step comprises the step of controlling the movement of the at least one slave device 170 such that:

[0060] - If the nominal target pose 180 is within the working area 174 (e.g. Figure 5 ), then controlling the orientation of at least one slave device 170 to converge toward the nominal target pose 180 (as shown diagrammatically in FIG. Fig. 9 and Figure 9a , where arrow A1 represents a converging movement of at least one slave device 170 to a modified target pose).

[0061] In more detail, the orientation of the at least one slave device 170 is controlled to converge towards the nominal target pose 180, for example by the normal dynamics of the teleoperation phase.

[0062] “Normal dynamics” means that the medical or surgical teleoperation is performed at the set “normal” teleoperation speed, that is, neither slowing down nor speeding up.

[0063] According to an embodiment, the orientation of the at least one slave device 170 is evaluated by evaluating the orientation of a virtual control point 600 associated with or integrated with the slave surgical instrument 170 .

[0064] Figure 3 The virtual control point 600 diagrammatically shown in FIG. 6 represents the origin of a local reference frame SF (“slave frame”) of the at least one slave device 170 .

[0065] According to an embodiment of the method, in combination with any of the foregoing, the controlling step comprises the step of controlling the movement of the at least one slave device 170 such that:

[0066] - From the termination of the controlled teleoperation phase, controlling the orientation of the at least one slave device 170 to converge to the modified target pose 184 .

[0067] In more detail, the orientation of the at least one slave device 170 is controlled to converge to the modified target pose 184, for example through the normal dynamics of the teleoperation phase defined above.

[0068] According to an embodiment of the method, in combination with any of the foregoing, the departure area 192 is defined as a set of all nominal target poses or modified target poses, wherein a corresponding first error function F1 is applied between the nominal target pose 180 or the modified target pose 184 of the at least one slave device 170 and the current pose of the at least one slave device 170. In this way, the first error function F1 is below a set first threshold.

[0069] The first error function F1 (also described in more detail below) is Fig.11 This is shown diagrammatically by arrows.

[0070] According to this embodiment of the method, the reentry region 196 is defined as the set of all nominal target poses or modified target poses, wherein a corresponding second error function F2 is applied between the nominal target pose 180 or the modified target pose 184 of the at least one slave device and the current pose of the at least one slave device 170. In this way, the second error function F2 is below a set second threshold.

[0071] The second error function F2 (also described in more detail below) is Fig.12 This is shown diagrammatically by arrows.

[0072] According to an embodiment of the method, in combination with any of the foregoing, not shown in the figure, the departure area 192 is a static area externally surrounding the working area 174 of the at least one slave device 170 .

[0073] According to an embodiment of the method, as an alternative to the previous embodiment, the departure area 192 is a dynamic area that changes with the current position of the at least one slave device 170 and at least partially extends outside the working area 174 of the at least one slave device 170 .

[0074] According to an embodiment of the method, in combination with any one of the foregoing Figure 8 As shown diagrammatically in FIG. 1 , the reentry region 196 is included in the retraction region 192 so that in the step of approaching the nominal target pose 180 to the working area 174 after the nominal target pose 180 leaves the working area 174 , the approach of the nominal target pose 180 from the working area 174 is evaluated.

[0075] In more detail, reentry region 196 is closely contained within departure region 192 .

[0076] By "closely contained" it is meant that the reentry region 196 is below and completely contained within the departure region 192.

[0077] For example, Figure 8 As shown diagrammatically in , the boundary of reentry region 196 is completely contained within departure region 192 .

[0078] According to an embodiment of the method, in combination with any of the foregoing, a modified target pose 184 is defined from the nominal target pose 180 as follows:

[0079] If nominal target pose 180 is within working area 174 , modified target pose 184 coincides with nominal target pose 180 .

[0080] If the nominal target pose 180 is outside the working area 174 , the modified target pose 184 is a pose that is as close as possible to the nominal target pose 180 at the border of the working area 174 .

[0081] Furthermore, according to other embodiments, if there are more positioning conditions of the nominal target pose 180 relative to the working area 174 , the modified target pose 184 is the pose closest to the current pose of the at least one slave device 170 .

[0082] According to an embodiment of the method, in combination with any of the foregoing, the rotation space of the at least one slave device 170 is limited to a rotation space that can be defined by including three Euler coordinates "roll" (in Figure 3RL in the figure), “pitch” (in Figure 3 PT in the figure) and "Yaw" (in the Figure 3 The rotation space of SO(3) is parameterized by the rotation coordinates (denoted by the reference symbol YW in the figure).

[0083] According to an embodiment of the method, in combination with any of the foregoing including said first error function F1 and said second error function F2, the slowed teleoperation phase comprises:

[0084] - Controlling the dynamics of said at least one slave device 170 so that the speed of said at least one slave device 170, with reference to the rotational coordinates, is lower than the speed value of said at least one slave device 170 provided in the teleoperation and / or is inversely proportional to said first error function F1 and said second error function F2 expressed in solid angles.

[0085] According to an embodiment of the method, in combination with the foregoing, the method comprises the following steps:

[0086] -Signaling to the operator that a slowed teleoperation phase is in progress, wherein the dynamics of the at least one slave device 170 are controlled so that the speed of the at least one slave device 170 is lower than the speed value of the at least one slave device 170 provided in the medical teleoperation and is inversely proportional to the first error function F1 and the second error function F2 expressed in solid angles.

[0087] According to an embodiment, the signaling step is performed continuously, for example by emitting an audio signal ("beep") that lasts during the slowed teleoperation.

[0088] According to an embodiment of the method, in combination with any of the foregoing, the nominal target pose 180 of the at least one slave device 170 comprises a rotational degree of freedom and other degrees of freedom relative to the rotational degree of freedom.

[0089] The further degrees of freedom are controlled in a manner that is independent of and unaffected by the determination of the orientation of the nominal target pose 180 of the at least one slave device 170 relative to the working area 174 with reference to the rotation coordinates.

[0090] According to an embodiment of the method, in combination with the previous embodiment, the control of the other degrees of freedom also takes place if the movement of the at least one slave device 170 with reference to the rotation coordinates has been prevented.

[0091] According to an embodiment of the method, in combination with any of the preceding wherein said other degrees of freedom are included, said other degrees of freedom comprise a translational degree of freedom.

[0092] According to this embodiment, if the orientation of the nominal target pose 180 is outside the working area 174 and outside the departure area 192, and thus rotating the coordinates is prevented, the method further comprises:

[0093] - hindering and / or preventing a rapid movement of said at least one slave device 170 with reference to said translational degree of freedom.

[0094] According to an embodiment of the method, as an alternative to the previous embodiment, wherein the other degrees of freedom include a translational degree of freedom, and wherein, if the orientation of the nominal target pose 180 is outside the working area 174 and outside the departure area 192, and thus rotating the coordinates is prevented, the method further comprises:

[0095] - limiting fast movements of said at least one slave device 170 with reference to said translational degree of freedom.

[0096] According to an embodiment of the method, in combination with any one of the foregoing including the first error function F1 and the second error function F2, the method includes the following steps: calculating the first error function F1 and / or the second error function F2 as the solid angle between the orientation of the nominal target posture 180 of the at least one slave device 170 and the orientation of the current posture of the at least one slave device 170.

[0097] According to an embodiment of the method, combined with the previous embodiment, the first error function F1 and / or the second error function F2 are calculated by torsion / swing decomposition of the angle between the nominal target pose 180 of the slave device 170 and the current pose of the at least one slave device 170 .

[0098] Swing angle (at Fig.12 , denoted diagrammatically by reference symbol SW in the figure, is the solid angle between the main direction of the nominal target pose 180 of the at least one slave device 170 and the orientation direction of the current pose of the at least one slave device 170.

[0099] The swivel angle denotes a rotation about a swivel axis which is orthogonal to a main orientation direction of the at least one master device 110 and the at least one slave device 170 .

[0100] Torsion angle (in Fig.12 , represented diagrammatically by reference numeral TW) is a solid angle about a main orientation direction of the at least one slave device 170 required for alignment with the nominal target pose 180, a rotation of the swing angle about the swing axis being applied to the orientation of the at least one slave device 170.

[0101] According to an embodiment of the method, in combination with any of the foregoing including said first error function and said second error function, the first error function F1 and the second error function F2 are scalar functions, and the first threshold and the second threshold are scalar values.

[0102] According to an embodiment of the method, in combination with any of the preceding ones including said first error function F1 and said second error function F2, the first threshold and the second threshold are equal.

[0103] According to an embodiment of the method, in combination with any of the foregoing including and as an alternative to the foregoing, the second threshold value is lower than the first threshold value.

[0104] According to an embodiment of the method, in combination with any of the foregoing including said first error function F1 and said second error function F2:

[0105] - said at least one slave device 170 is of the “end effector” type;

[0106] - The at least one master device 110 is of the "2-fold symmetric" type.

[0107] For example, refer to Figure 3 The at least one slave device 170 of the "end effector" type preferably comprises a pair of terminal gripping and / or cutting links 173, 175 ("instrument tips") articulated to one another, defining an opening / closing degree of freedom GRIP (in Figure 2 and Figure 3 ), and preferably further includes at least one other link 177, which supports the pair of terminal links 173, 175 and can be hinged relative to the frame 179 of at least one slave device 170 to form an articulated end actuator.

[0108] In addition, refer to Figure 2 Again, by way of example, the at least one master device 110 comprises two rigid parts 113, 115 which are constrained to rotate relative to each other about a common axis in the manner of a clamp or tweezers (e.g. Figure 2 ), wherein the two rigid components 113, 115 are substantially symmetrical with respect to the longitudinal axis MM of the main device 110.

[0109] If unilateral teleoperation is given between the at least one master device 110 (in this embodiment, of the "symmetric N-folded" type) and the at least one slave device 170 (microsurgical instrument), there are degrees of freedom of a translational nature (usually 3 mutually orthogonal directions), degrees of freedom of a rotational nature (whose spatial posture can usually be described by 3 consecutive rotations) and possible additional degrees describing the state of the microsurgical instrument, such as "closed" (or grasping).

[0110] As described above, in this case, unilateral teleoperation can be considered as an information flow between the at least one master device 110 and the at least one slave device 170 (surgical instrument), such as Figure 4 As shown in .

[0111] In this embodiment, the first error function F1 and the second error function F2 are calculated on two nominal targets spaced apart from each other by an angle equal to 180° with respect to a main direction of the at least one master device 110 .

[0112] The nominal target pose 180 used in the reentry phase is a pose with a smaller angular distance relative to the slave device 170 (referred to as "Flip active" mode).

[0113] According to an embodiment, combined with the previous one, the method comprises a step of preventing an orientation of said at least one master device of the “2-fold symmetry” type (called “Flip freeze” mode).

[0114] In more detail, the detection and transmission of the rotational degree of freedom of the roll RL to the at least one slave device 170 is necessarily affected by the axisymmetric nature relative to the axis of the at least one master device 110, ie there are two substantially equal 180° rotational poses.

[0115] For example Figure 3 As shown in , the at least one slave device 170 may have a roll RL degree of freedom about a slave roll axis SS, which may extend longitudinally along a frame 179 (eg, a spindle or rod) of the at least one slave device 170 .

[0116] According to an embodiment of the method, in combination with any of the foregoing including a signaling step, the signaling step alternatively or in combination comprises the following steps:

[0117] - provide an audio signal ("beep");

[0118] -Provide video signal (light changes);

[0119] - Provide messages on the video terminal.

[0120] According to an embodiment of the method, in combination with any of the foregoing, the transition between the step of preventing the rotational movement of at least one slave device 170 and the step of controlling the orientation of at least one slave device 170 to converge to a modified target pose 184, through a slowed teleoperation phase, is performed automatically without direct intervention of the operator 150 on any buttons and / or pedals.

[0121] According to an embodiment of the method, in combination with any one of the foregoing, the step of defining a nominal target pose 180 having a corresponding orientation in the rotational space of the at least one slave device 170 includes the step of calculating the orientation of the nominal target pose 180 based on the orientation of the at least one master device 110 in the rotational space of the at least one master device 110.

[0122] In an embodiment, alternatively or in combination with the previous embodiment, the step of defining a modified target pose (proxy) 184 in the rotation space of the at least one slave device 120 comprises the following steps: using a projection function, calculating the modified target pose (proxy) based on the nominal target pose 180 as a projection on the working area 174 of the at least one slave device 170 belonging to the rotation space of the at least one slave device 170, so that the modified target pose is within the working area 174 of the at least one slave device 170, wherein if the nominal target pose 180 belongs to the working area 174 of the at least one slave device 170, the nominal target pose 180 and the modified target pose 184 coincide.

[0123] In an embodiment, alternatively or in combination with the foregoing, the step of defining a departure area 192 and a re-entry area 196 centered on the current pose of the at least one slave device 170 includes: the departure area 192 is a first subspace of the rotation space of the at least one slave device 170, and is defined as evaluating the removal of the nominal target pose 180 from the working area 174 in the step of causing the nominal target pose 180 to leave / remove from the working area.

[0124] In an embodiment, alternatively or in combination with the foregoing, the reentry region 196 is defined as evaluating the proximity of the nominal target pose 180 to the working area 174 in the step of approaching the nominal target pose 180 to the working area once the nominal target pose 180 leaves the working area 174 .

[0125] Still refer to Figure 1-10 , and in particular Figure 1-3 , as described above, the following describes a robotic system 100 for medical or surgical teleoperation included in the present invention.

[0126] Such a robotic system 100 comprises at least one handheld host device 110 adapted to be moved by an operator 150 .

[0127] The system 100 includes at least one slave robotic assembly 120 including at least one slave device 170 (or slave surgical instrument 170 ) adapted to be controlled by the at least one master device 110 .

[0128] The system 100 further comprises a control unit configured to control the at least one slave device 170 based on the movement of the at least one master device (110) during teleoperation.

[0129] The control unit is further configured to perform the following actions:

[0130] - defining a nominal target pose 180 having a corresponding orientation in the rotational space of the at least one slave device 170, the at least one slave device 170 having a corresponding working area 174 belonging to the rotational space of the at least one slave device 170;

[0131] - defining a modified target pose ("proxy") 184 in the rotational space of the at least one slave device 170, the modified target pose being defined so that it is within the working area 174 of the at least one slave device 170 (e.g. Figure 6 , 6a , 7, 7a, 9 and 9a);

[0132] - defining a departure area 192 centered around the current pose of the at least one slave device 170 (see e.g. Figure 6 , 6a , 7, 7a, 8 and 11) and reentry region 196 (see e.g. Figure 8 , 9 , 9a, 10 and 12), wherein the departure area 192 is a first subspace of the rotation space of the at least one slave device 170, and wherein the re-entry area 196 is a second subspace of the rotation space of the at least one slave device 170.

[0133] The control unit of the robotic system 100 is further configured to control the movement of the at least one slave device 170 such that:

[0134] a) If the nominal target pose 180 is outside the working area 174, and the nominal target pose 180 and the modified target pose 184 are inside the departure area 192 (e.g. Figure 6 and Figure 6a ), then controlling the orientation of at least one slave device 170 to converge to a modified target pose 184 (such as Figure 6 and Figure 6a , where arrow A1 represents a convergent movement of at least one slave device 170 to a modified target pose 184);

[0135] -b) if at least one of the nominal target pose 180 and the modified target pose 184 is outside the departure area 192 (e.g. Figure 7 and Figure 7a , wherein the nominal target pose 180 is outside the departure region 192), then the rotational movement of the at least one slave device 170 is prevented until both the nominal target pose 180 and the modified target pose 184 enter the aforementioned reentry region 196 (such as, for example Fig. 9 and Figure 9a )

[0136] -c) when both the nominal target pose 180 and the modified target pose 184 re-enter the re-entry region 196 after leaving the working region 174 (e.g., Fig. 9 and Figure 9a ), through a slowed teleoperation phase, controlling the orientation of at least one slave device 170 to converge to a modified target pose 184 (such as Fig. 9 and Figure 9a , where arrow A1 represents the convergence movement of the at least one slave device 170 to the modified target pose), the slowed teleoperation phase ends when the orientation of the at least one slave device 170 converges to the modified target pose 184 (e.g. Fig.10 As shown in the diagram, Fig. 9 and Figure 9a , only the at least one slave device 170 is shown to completely overlap with the modified target position 184).

[0137] According to several possible implementations of the robot system 100 , the control unit is configured to execute a method of controlling a slave device according to any implementation described in this specification.

[0138] Still refer to the above Figure 1-12 , 6a, 7a and 9a, a method of controlling a slave device 170 of a robotic system 100 for medical or surgical teleoperation (hereinafter also referred to as a robotic system or simply a system) further forms the subject of the present invention.

[0139] The robotic system 100 includes at least one handheld host device 110 and is adapted to be moved by an operator 150 .

[0140] The at least one master device 110 has been described above.

[0141] The robotic system 100 further includes at least one slave robotic assembly 120 including at least one slave device 170 (or a surgical instrument 170 adapted to be controlled by the master device 110).

[0142] The slave robot assembly 120 has been described above.

[0143] Again, referring to the method according to this embodiment and Figure 5-12 , 6a, 7a and 9a, the method includes the step of defining a nominal target pose 180, which has a corresponding orientation in the rotational workspace of the at least one slave device 170 defined by the rotational coordinates representing the rotational measurement, corresponding to the corresponding pose of the at least one master device 110, which has a corresponding orientation in the rotational workspace of the at least one master device 110 defined by the rotational coordinates representing the rotational measurement.

[0144] The orientation of the nominal target pose 180 of the at least one slave device 170 and the orientation of the pose of the at least one master device 110 are characterized by rotated coordinates in a rotational workspace of the at least one slave device 170 .

[0145] The method further comprises the step of determining an orientation of a nominal target pose 180 of said at least one slave device 170 with reference to said rotated coordinates relative to said at least one working area (workspace) 174 .

[0146] The method further comprises the step of controlling the movement of the at least one slave device 170 such that:

[0147] - If the orientation of the nominal target pose 180 (with reference to the rotation coordinates) is within the workspace 174 (e.g. Figure 5 ), the at least one slave device 170 follows through the normal teleoperation phase (defined above) until the orientation of the nominal target pose 180 is reached (as shown in Figure 5 , where arrow A1 represents a converging movement of at least one slave device 170 to a nominal target pose 180).

[0148] The method further performs the step of controlling the movement of the at least one slave device 170 such that:

[0149] - If the orientation (reference rotation coordinates) of the nominal target pose 180 is outside the working area (working space) 174 (e.g. Figure 6 , 6a, 7, 7a, 9, 9a and 10), then define a first error function F1 and a second error function F2 (both described above) between the orientation of the nominal target pose 180 of the at least one slave device 170 and the orientation of the current pose of the at least one slave device 170, and perform the following actions:

[0150] If the value assumed by the first error function F1 is lower than a set first threshold, the movement of the at least one slave device 170 is controlled so that the rotation coordinates of the at least one slave device 170 converge towards the orientation of the pose.

[0151] In an embodiment, in combination with the previous embodiment, the value of the first error function F1 is compared with the established first threshold value to verify whether there is a nominal target pose 180 (such as, for example, Figure 6 , 6a , 7, 7a, 9, 9a and 10), wherein the first departure area 192 is defined as evaluating the removal of the nominal target posture 180 from the working area 174 during the phase of leaving / removing the nominal target posture 180 from the working area 174.

[0152] According to an embodiment, in combination with any one of the two aforementioned embodiments, the value of the second error function F2 is compared with a set second threshold value to verify whether the nominal target posture 180 exists within a second re-entry area 196 defined around the current position of the at least one slave device 170 in the rotation space of the at least one slave device 170, wherein the second re-entry area 196 is defined as evaluating the approach of the nominal target posture 180 from the working area 174 in the step of bringing the nominal target posture 180 close to the working area 174 after the nominal target posture 180 leaves the working area.

[0153] In an embodiment, in combination with the previous embodiment, the second reentry region 196 is a dynamic region that changes with the current posture of the at least one slave device 170 and at least partially extends outside the working region 174 of the at least one slave device 170 (e.g., Fig. 9 , 9a and 10).

[0154] As can be seen, the objects of the invention are fully achieved.

[0155] In fact, according to the method of the present invention, the slave movement of the slave device is controlled according to the master device, according to the plan and based on the control algorithm, so as to solve or at least alleviate the problems and disadvantages encountered in the prior art.

[0156] In particular, the method approaches the physical limits of movement of the slave devices in an accurate and timely manner through a slave device that can be controlled by a master device that can be moved by an operator.

[0157] With the proposed solution, where a nominal target pose 180 (with its orientation in the rotational space of the slave device) is defined by movements of the master device that are not constrained by the user, and where the nominal target pose 180 is infeasible (unreachable) for the slave device because it is outside the rotational space of the slave device, the method (and associated system) defines a modified target pose 184 that is essentially a projection of the target pose 180 in the rotational space of the slave device, e.g., the orientation of the target pose 180 that is closest to being inside the rotational space of the slave device.

[0158] Thus, even if the posture commanded by the master device (i.e., the nominal target posture 180) is outside the rotational space of the slave device or exceeds the physical limits of one or more rotational joints of the slave surgical instrument, slowed ("smooth") teleoperation can be achieved without any failures or interruptions.

[0159] Furthermore, in order to allow control of the slave device also close to the constraints of the slave device's rotational space, for example, when the nominal target pose 180 controlled by the unconstrained master device is outside of said rotational space of the slave device and therefore unreachable by the slave device, by virtue of the proposed solution, two rotational attractor spaces (e.g., roll-pitch-yaw) are defined around the current pose of the slave device, referred to as the departure region 192 and the reentry region 196.

[0160] Thus, the method (and related system) selectively prevents or enables movement of a slave device based on the positions of the nominal target pose 180 and the modified target pose 184 relative to the aforementioned rotational attraction subspace.

[0161] In fact, the current pose of the slave device 170 is already close to the physical limits of rotation, so that the definition of this departure and re-entry attractor space allows to maintain intuitive and slowed ("smooth") teleoperation, slowing down the rotational dynamics (i.e., velocity or acceleration) of the slave device when necessary.

[0162] Preferably, as described above, by predicting a "slowed down teleoperation" state, ie slowing down the dynamics of the slave device, the aim is to indicate a scaling of the speed and rotational acceleration of the slave device, rather than a scaling of the position.

[0163] The slowed teleoperation state allows slowing down the rotational dynamics (velocity / acceleration) of the slave device close to the limits of its rotational space (e.g., the limit travel of the rotational joints of an articulated surgical instrument), avoiding water hammer effects and allowing the user to perform intuitive control even close to said limits, where certain conditions are verified relative to a defined attractor space.

[0164] The intuitiveness of use is particularly facilitated by the fact that the method (and the related system) maintains the teleoperation conditions without interrupting them even if the controlled pose is outside the slave rotation space, as well as by the ability to predict the dynamics of slowing down, which allows minimizing situations in which the slave device moves without responding to commands given by an unconstrained master device and / or without force feedback.

[0165] With the proposed solution, a master device that is not constrained by an operating console (and therefore may not have limits or physical limit switches for rotation) is allowed to finely control the slave device, even in orientation, avoiding interruption of teleoperation even if the controlled pose (nominal target pose 180) is outside the rotational space of the slave device.

[0166] The modified target pose 184 is preferably the closest to the nominal target pose 180 from within the rotation space and within the boundaries of the attractor space (departure region 192, reentry region 196).

[0167] Those skilled in the art may make changes and adaptations to the embodiments of the above methods and related systems, or may replace elements with other functionally equivalent elements to meet the needs of the situation, but without departing from the scope of the following claims. Each of the features described as belonging to possible embodiments can be implemented independently of other described embodiments.

Claims

1. A method of controlling a slave device (170) of a robotic system (100) for medical or surgical teleoperation, wherein: The robotic system comprises at least one handheld master device (110) adapted to be moved by an operator (150), and at least one slave device (170) adapted to be controlled by the at least one master device (110), the method comprising the following steps: - defining a nominal target pose (180) having a corresponding orientation in the rotational space of the at least one slave device (170), the at least one slave device (170) having a corresponding working area (174) belonging to the rotational space of the at least one slave device (170); - defining a modified target pose (184) in the rotational space of the at least one slave device (170), the modified target pose being defined so that it is within the working area (174) of the at least one slave device (170); - defining a departure region (192) and a reentry region (196) centered on a current pose of the at least one slave device (170), wherein the departure region (192) is a first subspace of a rotation space of the at least one slave device (170), and wherein the reentry region (196) is a second subspace of the rotation space of the at least one slave device (170); - controlling the movement of the at least one slave device (170) such that: a) if the nominal target pose (180) is outside the working area (174), and the nominal target pose (180) and the modified target pose (184) are inside the departure area (192), controlling the orientation of the at least one slave device (170) to converge to the modified target pose (184); -b) if at least one of the nominal target pose (180) and the modified target pose (184) is outside the departure region (192), preventing rotational movement of the at least one slave device (170) until both the nominal target pose (180) and the modified target pose (184) enter the reentry region (196); -c) when both the nominal target pose (180) and the modified target pose (184) return to the reentry region (196) after leaving the working region, controlling the orientation of the at least one slave device (170) to converge to the modified target pose (184) through a slowed teleoperation phase, and when the orientation of the at least one slave device (170) converges to the modified target pose (184), the slowed teleoperation phase ends.

2. The method according to claim 1, wherein: The controlling step comprises controlling the movement of the at least one slave device (170) such that: - if the nominal target pose (180) is within the working area (174), controlling the orientation of the at least one slave device (170) to converge towards the nominal target pose (180).

3. A method according to any one of the preceding claims, wherein: The controlling step comprises controlling the movement of the at least one slave device (170) such that: - from the termination of the controlled teleoperation phase, controlling the orientation of the at least one slave device (170) to converge to the modified target pose (184).

4. A method according to any one of the preceding claims, wherein: - the departure area (192) is defined as a set of all the nominal target poses or modified target poses, wherein a corresponding first error function (F1) is applied between the nominal target pose (180) or the modified target pose (184) of the at least one slave device and the current pose of the at least one slave device, such first error function being below a set first threshold; - The reentry region (196) is defined as the set of all nominal target poses or modified target poses, wherein a corresponding second error function (F2) is applied between the nominal target pose (180) or the modified target pose (184) of the at least one slave device and the current pose of the at least one slave device (170), and such second error function is below a set second threshold.

5. A method according to any one of the preceding claims, wherein: The departure area (192) is a static area externally surrounding the working area (174) of the at least one slave device (170).

6. The method according to any one of the preceding claims 1 to 4, wherein: The departure area (192) is a dynamic area that changes with the current position of the at least one slave device (170) and at least partially extends outside the working area (174) of the at least one slave device.

7. A method according to any one of the preceding claims, wherein: The reentry region (196) is included in the departure region (192) so that in the step of bringing the nominal target pose (180) closer to the working area (174) after the nominal target pose (180) leaves the working area (174), the approach of the nominal target pose (180) from the working area (174) is evaluated.

8. A method according to any one of the preceding claims, wherein: The modified target pose (184) is defined based on the nominal target pose (180) as follows: - if the nominal target pose (180) is within the working area (174), the modified target pose (184) coincides with the nominal target pose (180); If the nominal target pose (180) is outside the working area (174), the modified target pose (184) is a pose that is as close as possible to the nominal target pose (180) at the boundary of the working area (174).

9. A method according to any one of the preceding claims, wherein: The rotation space of the at least one slave device (170) is a rotation space constrained by SO (3) parameterizable by the rotation coordinates comprising three Euler coordinates roll (RL), pitch (PT) and yaw (YW).

10. The method according to any one of the preceding claims 4 to 9, wherein: The slowed teleoperation phase includes: - controlling the dynamics of the at least one slave device (170) so that the speed of the reference rotation coordinates of the at least one slave device (170) is lower than the speed value of the at least one slave device (170) provided in the teleoperation and / or is inversely proportional to the first error function (F1) and the second error function (F2) expressed in solid angle.

11. The method according to claim 10, comprising: -Signaling the operator (150) that the slowed teleoperation phase is in progress, wherein the dynamics of the at least one slave device (170) are controlled so that the speed of the at least one slave device (170) is lower than the speed value of the at least one slave device (170) provided in the medical teleoperation and is inversely proportional to the first error function (F1) and the second error function (F2) expressed in solid angles.

12. A method according to any one of the preceding claims, wherein: The nominal target pose (180) of the at least one slave device (170) comprises a rotational degree of freedom and other degrees of freedom relative to the rotational degree of freedom, wherein the other degrees of freedom are controlled in a manner that is independent of and unaffected by the determination of the orientation of the nominal target pose (180) of the at least one slave device (170) relative to the working area (174) with reference to the rotational coordinates.

13. The method according to claim 12, wherein: If movement of the at least one slave device (170) with reference to the rotational coordinates has been prevented, control of the other degrees of freedom may also occur.

14. The method according to any one of the preceding claims 12 to 13, wherein: The other degrees of freedom include a translational degree of freedom, and wherein if the orientation of the nominal target pose (180) is outside the working area (174) and outside the departure area (192), and thus the rotation of the coordinates is prevented, the method further comprises: - hindering and / or preventing rapid movement of said at least one slave device (170) with reference to said translational degree of freedom.

15. The method according to any one of the preceding claims 12 to 13, wherein: The other degrees of freedom include a translational degree of freedom, and wherein if the orientation of the nominal target pose (180) is outside the working area (174) and outside the departure area (192), and thus the rotation of the coordinates is prevented, the method further comprises: - limiting rapid movements of said at least one slave device (170) with reference to said translational degree of freedom.

16. The method according to any one of the preceding claims 4 to 15, comprising: - calculating the first error function (F1) and / or the second error function (F2) as a solid angle between the orientation of the nominal target pose (180) of the at least one slave device and the current pose orientation of the at least one slave device (170).

17. The method according to claim 16, wherein: The first error function and / or the second error function are calculated by torsion / swing decomposition of the angle between the slave device and the current posture of the at least one slave device (170), the swing angle being the solid angle between the main direction of the nominal target posture (180) of the at least one slave device and the main direction of the current posture orientation of the at least one slave device (170), the swing angle being rotated around a swing axis orthogonal to the main orientation directions of the at least one master device (100) and the at least one slave device (170), the torsion angle being the solid angle around the main orientation direction of the at least one slave device (170) required for alignment with the nominal target posture (180), and the rotation of the swing angle around the swing axis being applied to the orientation of the at least one slave device (170).

18. A method according to any one of the preceding claims 4 to 17, wherein: The first error function (F1) and the second error function (F2) are scalar functions, and the first threshold and the second threshold are scalar values.

19. A method according to any one of the preceding claims 4 to 18, wherein: The first threshold and the second threshold are the same.

20. The method according to any one of the preceding claims 4 to 18, wherein: The second threshold is smaller than the first threshold.

21. A method according to any one of the preceding claims, wherein: - the at least one slave device (170) comprises two terminal links (173, 175) defining an opening / closing degree of freedom (GP); - said at least one master device (110) is of "2-fold symmetric" type; - the first error function (F1) and the second error function (F2) are calculated on two nominal target poses spaced apart from each other by an angle equal to 180° with respect to a main direction of the at least one master device (110), the nominal target pose (180) used in the reentry phase having a smaller angular distance relative to the slave device (170).

22. The method according to claim 21, comprising: - preventing an orientation of said at least one master device (110) of the "2-fold symmetry" type.

23. The method according to any one of claims 11 to 22, wherein: The signalling phase may alternatively or in combination include: - provide audio signals; -Provide video signal; - Provide messages on the video terminal.

24. A method according to any one of the preceding claims, wherein: By means of a slowed teleoperation phase, switching between the step of preventing the rotational movement of the at least one slave device (170) and the step of controlling the orientation of the at least one slave device (170) to converge to the modified target pose (184) is performed automatically without direct intervention of the operator (150) at buttons and / or pedals.

25. A method according to any one of the preceding claims, wherein: - the step of defining a nominal target pose (180) having a corresponding orientation in the rotational space of the at least one slave device (170) comprises the step of calculating the orientation of the nominal target pose (180) as a function of the orientation of the at least one master device (110) in the rotational space of the at least one master device (110); and / or where - the step of defining a modified target pose (184) in the rotation space of the at least one slave device (170) comprises the following steps: using a projection function, calculating the modified target pose (184) from the nominal target pose (180) as a projection on the working area (174) of the at least one slave device belonging to the rotation space of the at least one slave device (170), so that the modified target pose (184) is within the working area (174) of the at least one slave device (170), wherein if the nominal target pose (180) belongs to the working area (174) of the at least one slave device (170), the nominal target pose (180) and the modified target pose (184) coincide; and / or where - the step of defining a departure region (192) and a reentry region (194) centered on the current pose of the at least one slave device (170) comprises: the departure region (192) is a first subspace of the rotation space of the at least one slave device and is defined to evaluate the removal of the nominal target pose (180) from the working area (174) in the step of leaving / removing the nominal target pose (180) from the working area (174), and / or where The reentry region (196) is defined as once the nominal target pose (180) leaves the working region (174), in the step of bringing the nominal target pose (180) closer to the working region, evaluating the proximity of the nominal target pose (180) to the working region (174).

26. A method according to any one of the preceding claims, wherein: The at least one master device (110) is of a non-force feedback type for single-sided teleoperation; and / or wherein The at least one master device (110) is of a type that is mechanically unconstrained to a control console (140) of the robotic system (100).

27. A robotic system (100) for medical or surgical teleoperation, comprising: - at least one handheld host device (110) adapted to be moved by an operator (150); - at least one slave device (170) adapted to be controlled by said at least one master device (100); - a control unit configured to control the at least one slave device (170) based on the movement of the at least one master device (110) during teleoperation, Wherein, the control unit is further configured to: - defining a nominal target pose (180) having a corresponding orientation in the rotational space of the at least one slave device (170), the at least one slave device (170) having a corresponding working area (174) belonging to the rotational space of the at least one slave device (170), - defining a modified target pose (184) in the rotational space of the at least one slave device (170), the modified target pose being defined such that it is within the working area (174) of the slave device; - defining a departure region (192) and a reentry region (196) centered on a current pose of the at least one slave device (170), wherein the departure region (192) is a first subspace of a rotation space of the at least one slave device (170), and wherein the reentry region (196) is a second subspace of the rotation space of the at least one slave device (170); - controlling the movement of the at least one slave device (170) such that: a) if the nominal target pose (180) is outside the working area (174), and the nominal target pose (180) and the modified target pose (184) are inside the departure area (192), controlling the orientation of the at least one slave device (170) to converge to the modified target pose (184); -b) if at least one of the nominal target pose (180) and the modified target pose (184) is outside the departure region (192), preventing rotational movement of the at least one slave device (170) until both the nominal target pose (180) and the modified target pose (184) enter the aforementioned reentry region (196); -c) when both the nominal target pose (180) and the modified target pose (184) return to the reentry region (196) after leaving the working region (174), the orientation of the at least one slave device (170) is controlled to converge to the modified target pose (184) through a slowed teleoperation phase, and the slowed teleoperation phase ends when the orientation of the at least one slave device (170) converges to the modified target pose (184).

28. The robotic system (100) of claim 27, wherein: The control unit is configured to control the movement of the at least one slave device (170) such that: - if the nominal target pose (180) is within the working area (174), controlling the orientation of the at least one slave device (170) to converge towards the nominal target pose (180).

29. The robot system (100) according to any one of the preceding claims 27 or 28, wherein: The control unit is configured to control the movement of the at least one slave device (170) such that: - from the termination of the controlled teleoperation phase, controlling the orientation of the at least one slave device (170) to converge to the modified target pose (184).

30. The robotic system (100) according to any one of the preceding claims 27 to 29, wherein: - the departure area (192) is defined as a set of all the nominal target poses or modified target poses, wherein a corresponding first error function (F1) is applied between the nominal target pose (180) or the modified target pose (184) of the at least one slave device and the current pose of the at least one slave device, such first error function being below a set first threshold; - The reentry region (196) is defined as the set of all nominal target poses or modified target poses, wherein a corresponding second error function (F2) is applied between the nominal target pose (180) or the modified target pose (184) of the at least one slave device and the current pose of the at least one slave device (170), and such second error function is below a set second threshold.

31. The robot system (100) according to any one of the preceding claims 27 to 30, wherein: The departure area (192) is a static area externally surrounding the working area (174) of the at least one slave device (170).

32. The robot system (100) according to any one of the preceding claims 27 to 30, wherein: The departure area (192) is a dynamic area that changes with the current position of the at least one slave device (170) and at least partially extends outside the working area (174) of the at least one slave device.

33. The robot system (100) according to any one of the preceding claims 27 to 32, wherein: The reentry region (196) is included in the departure region (192) so that in the step of bringing the nominal target pose (180) closer to the working area (174) after the nominal target pose (180) leaves the working area (174), the approach of the nominal target pose (180) from the working area (174) is evaluated.

34. The robot system (100) according to any one of the preceding claims 27 to 33, wherein: The modified target pose (184) is defined based on the nominal target pose (180) as follows: - if the nominal target pose (180) is within the working area (174), the modified target pose (184) coincides with the nominal target pose (180); If the nominal target pose (180) is outside the working area (174), the modified target pose (184) is a pose that is as close as possible to the nominal target pose (180) at the boundary of the working area (174).

35. The robot system (100) according to any one of the preceding claims 27 to 34, wherein: The rotation space of the at least one slave device (170) is a rotation space constrained by SO (3) parameterizable by the rotation coordinates comprising three Euler coordinates roll (RL), pitch (PT) and yaw (YW).

36. The robot system (100) according to any one of the preceding claims 30 to 35, wherein: The slowed teleoperation phase includes: - controlling the dynamics of the at least one slave device (170) so that the speed of the reference rotation coordinates of the at least one slave device (170) is lower than the speed value of the at least one slave device (170) provided in the teleoperation and / or is inversely proportional to the first error function (F1) and the second error function (F2) expressed in solid angle.

37. The robotic system (100) of claim 36, wherein: The control unit is configured to: -Sending a signal to the operator (150) that the slowed teleoperation phase is in progress, wherein the dynamics of the at least one slave device (170) are controlled so that the speed of the at least one slave device (170) is lower than the speed value of the at least one slave device (170) provided in the medical teleoperation and is inversely proportional to the first error function (F1) and the second error function (F2) expressed in solid angles.

38. The robot system (100) according to any one of the preceding claims 27 to 37, wherein: The nominal target pose (180) of the at least one slave device (170) comprises a rotational degree of freedom and other degrees of freedom relative to the rotational degree of freedom, wherein the other degrees of freedom are controlled in a manner that is independent of and unaffected by the determination of the orientation of the nominal target pose (180) of the at least one slave device (170) relative to the working area (174) with reference to the rotational coordinates.

39. The robotic system (100) of claim 38, wherein: If movement of the at least one slave device (170) with reference to the rotational coordinates has been prevented, control of the other degrees of freedom may also occur.

40. The robot system (100) according to any one of the preceding claims 38 or 39, wherein: The other degrees of freedom include a translational degree of freedom, and wherein, if the orientation of the nominal target pose (180) is outside the working area (174) and outside the departure area (192), and thus the rotation of the coordinates is prevented, the control unit is further configured to: - hindering and / or preventing rapid movement of said at least one slave device (170) with reference to said translational degree of freedom.

41. The robot system (100) according to any one of the preceding claims 38 or 39, wherein: The other degrees of freedom include a translational degree of freedom, and wherein, if the orientation of the nominal target pose (180) is outside the working area (174) and outside the departure area (192), and thus the rotation of the coordinates is prevented, the control unit is further configured to: - limiting rapid movements of said at least one slave device (170) with reference to said translational degree of freedom.

42. The robot system (100) according to any one of the preceding claims 30 to 41, wherein: The control unit is configured to: - calculating the first error function (F1) and / or the second error function (F2) as a solid angle between the orientation of the nominal target pose (180) of the at least one slave device and the current pose orientation of the at least one slave device (170).

43. The robotic system (100) of claim 42, wherein: The first error function and / or the second error function are calculated by torsion / swing decomposition of the angle between the slave device and the current posture of the at least one slave device (170), the swing angle being the solid angle between the main direction of the nominal target posture (180) of the at least one slave device and the main direction of the current posture orientation of the at least one slave device (170), the swing angle being rotated around a swing axis orthogonal to the main orientation directions of the at least one master device (100) and the at least one slave device (170), the torsion angle being the solid angle around the main orientation direction of the at least one slave device (170) required for alignment with the nominal target posture (180), and the rotation of the swing angle around the swing axis being applied to the orientation of the at least one slave device (170).

44. The robot system (100) according to any one of the preceding claims 30 to 43, wherein: The first error function (F1) and the second error function (F2) are scalar functions, and the first threshold and the second threshold are scalar values.

45. The robot system (100) according to any one of the preceding claims 30 to 44, wherein: The first threshold and the second threshold are the same.

46. ​​The robot system (100) according to any one of the preceding claims 30 to 44, wherein: The second threshold is smaller than the first threshold.

47. The robotic system (100) according to any one of the preceding claims 27 to 46, wherein: - the at least one slave device (170) comprises two terminal links (173, 175) defining an opening / closing degree of freedom (GP); - said at least one master device (110) is of "2-fold symmetric" type; - the first error function (F1) and the second error function (F2) are calculated on two nominal target poses spaced apart from each other by an angle equal to 180° with respect to a main direction of the at least one master device (110), the nominal target pose (180) used in the reentry phase having a smaller angular distance relative to the slave device (170).

48. The robotic system (100) of claim 47, comprising: - preventing an orientation of said at least one master device (110) of the "2-fold symmetry" type.

49. The robot system (100) according to any one of claims 37 to 48, wherein: The control unit for signaling to the operator (150) that it is in a slowed teleoperation phase is alternatively or in combination configured to: - provide audio signals; -Provide video signal; - Provide messages on the video terminal.

50. The robot system (100) according to any one of the preceding claims 27 to 49, wherein: By means of a slowed teleoperation phase, switching between the step of preventing the rotational movement of the at least one slave device (170) and the step of controlling the directional convergence of the at least one slave device (170) to the modified target pose (184) is performed automatically without direct intervention of the operator (150) at buttons and / or pedals.

51. The robotic system (100) according to any one of the preceding claims 27 to 50, wherein: - the control unit for defining a nominal target pose (180) having a corresponding orientation in the rotational space of the at least one slave device (170) is configured to calculate the orientation of the nominal target pose (180) as a function of the orientation of the at least one master device (110) in the rotational space of the at least one master device (110); and / or where - the control unit for defining a modified target pose (184) in the rotational space of the at least one slave device (170) is configured to: calculate the modified target pose (184) from the nominal target pose (180) as a projection on the working area (174) of the at least one slave device belonging to the rotational space of the at least one slave device (170) using a projection function, so that the modified target pose (184) is within the working area (174) of the at least one slave device (170), wherein if the nominal target pose (180) belongs to the working area (174) of the at least one slave device (170), the nominal target pose (180) and the modified target pose (184) coincide; and / or where - the control unit in defining a departure region (192) and a reentry region (194) centered on the current pose of the at least one slave device (170) comprises: the departure region (192) is a first subspace of the rotation space of the at least one slave device and is defined to evaluate the removal of the nominal target pose (180) from the working area (174) in the step of leaving / removing the nominal target pose (180) from the working area (174), and / or where The reentry region (196) is defined as once the nominal target pose (180) leaves the working region (174), in the step of bringing the nominal target pose (180) closer to the working region, evaluating the proximity of the nominal target pose (180) to the working region (174).

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