EP3247303A1

EP3247303A1 - Telesurgical system with intrinsic haptic feedback by dynamic characteristic line adaptation for gripping force and end effector coordinates

Info

Publication number: EP3247303A1
Application number: EP16703921.3A
Authority: EP
Inventors: Carsten Neupert; Christian Hatzfeld; Sebastian Matich
Original assignee: Technische Universitaet Darmstadt
Current assignee: Technische Universitaet Darmstadt
Priority date: 2015-01-19
Filing date: 2016-01-18
Publication date: 2017-11-29
Also published as: DE102015100694A1; US20180132953A1; WO2016120110A1

Abstract

The invention relates to a telesurgical system comprising: - a slave, which has a drive unit driving a gripping end effector, a kinematic coordinate of the end effector and a gripping force F_effector being determinable, - a camera, preferably integrated into the slave and being oriented towards the end effector, and - a master, which is remotely connected to the slave, having at least one control unit on which an user can exert a gripping force F_G, said gripping force being transmitted to the slave, and having a visual user interface representing the image of the camera, with the proviso that F_G is linearly dependent on the kinematic coordinate and F_effector.

Description

Teleoperation system with intrinsic haptic feedback by dynamic characteristic adaptation for gripping force and

Endeffektorkoordinaten

The invention relates to a teleoperation system based on a master-slave structure.

Background of the invention

Background of the invention is the development of a

Teleoperations system for a medical application. The

Teleoperation system should provide haptic feedback

Representation of interaction forces preferably provide between an end effector and the surrounding tissue, For use in surgery exist

Telemanipulation systems hereinafter also called teleoperation systems, which can be referred to as a remote-controlled system. In particular, the limited integration of haptics and the

Implementation as a pure telemanipulation system are limitations for a more extensive use in surgical subjects. Through the use of lightweight robotics with extensive integrated force / moment sensors, completely new approaches for surgical procedures are possible. The integration of haptic

Processes in the context of therapeutic and diagnostic concepts in medicine represent the next step for an intuitive human

Machine interface dar. Also the extension of the pure

Telemanipulation to a teleoperation with the integration autonomous Teilverrichtungen relieves the doctor of concentration-reducing routines.

The term haptic comes from the Greek. He means

"tactile" or "suitable for touching". In principle, therefore, once all the media offer the possibility of haptic

Perception. They feel in a certain way. A table surface can be smooth or rough. It is therefore a perception, which is primarily done by the fingers of the hand.

The pseudo-haptic feedback is passed to the user

additional visual information gives a haptic impression. Thus, e.g. the information on a screen gives the user the impression that there is haptic feedback, which is actually not the case or only minimal.

In a teleoperation system based on a master-slave

Structure includes the master at which the doctor sits, one

Operating unit. The operating unit preferably contains two operating means for the left and right hand (left, right). The doctor interacts with the operating means. The operating area is presented to the user through a visual user interface, such as a screen. The doctor should see on the screen only the operating area, or the end effector. For an intuitive operation, it can be advantageous if you do not see your own hands during teleoperation. In this case, it is particularly advantageous in the case of pseudo-haptics, if one can not see one's own fingers, since this avoids the irritation caused by the missing or expectation-deviating movement (deflection) of the finger. FIG. 1 shows a corresponding one

System.

The slave, also referred to as a single-port robot, consists of a drive unit. The movements generated in the drive units control two parallel kinematic manipulators (left / right) via drive struts. At the top of each

Manipulator is the Tool Center Point (TCP) which is used to hold surgical tools (end effector), and For example, it can be positioned in the situs. The slave has one or more drives, which are arranged as distally as possible distally of the end effector in the extension of the drive struts of the parallel kinematic manipulator in order to

Sterility does not have a negative impact. The slave further comprises a camera, lighting means and preferably one

Working channel. The coupling of the two systems takes place

electrically in the control computer.

FIG. 2 shows the system structure of a conventional system. This system consists of an impedance system called a master, and an admittance system called a slave, also called a slave. The master system comprises a man-machine interface, which as a rule consists of a screen and corresponding input means. The user gives position instructions to the slave via a kinematic structure. About appropriate position sensors, these are connected to a

Guided control unit, which then drives one or more actuators, or which is arranged in the slave. The actuator in turn controls a kinematic structure, which then has a

Has access to the environment or the tissue. By one or more force sensors is given by the slave via the control unit feedback, which in turn drives one or more actuators in the master unit, which has an influence on the

kinematic structure, creating a haptic feedback to the user. Through these sensors and actuators, the user receives an indirect feedback.

Overview of the invention

The aim of the invention is now to ensure a realistic pseudohaptic feedback, without integrating a (further) actuator in the user interface for the active generation of the haptic feedback. Likewise, by this method on a

sophisticated force sensors are dispensed with in the end effector, The aim of the invention is the generation of a pseudohaptisehen

Feedbacks in the operating unit of a teleoperation system. In this case, compared to the current state of the art, waived an actuator in the user interface and reduces the metrological effort in the end effector. The pseudo-haptic feedback arises from the use of the application's visual feedback and the processing of different ones

Sensory impressions to a consistent sensation by the user.

Specifically, it is a teleoperation system,

full:

a slave having a drive unit which drives a cross-end effector, a kinematic one

Coordinate of the end effector and a gripping force F _{effector can be} determined The kinematic coordinate is, for example, a closing angle for a rotational freedom line or a travel path for the translational freedom line of the end effector. In this patent, the

Locking angle Phi used representative of the class of end effectors described above, it should thus also include the kinematic coordinate. This is the case in particular if the end effector is not closed in a scissor-like or rotational manner via a joint, but over an e. G. linear travel path. The drive unit is also called actuator and may be one or more motors with and / or without transmission or clutch. This motor is located in a slave housing, preferably away from the tissue to prevent contamination. The motor drives the end effector, and in particular its gripper. It should be noted that there are other engines for more

Functions of the end effector or other end effectors to implement. Also, there may be other engines to perform multi-dimensional movements.

- Another component of the teleoperation system is a camera, which is preferably integrated in the slave, and which is aligned with the end effector. The camera may also be attached to another device, but should allow a view of the end effector and its gripper. The camera allows a visual feedback. In a further embodiment, the Camera image, an additional digital representation of the current Endeffektorkoordinate be superimposed. (Angle, strokes that move on each other, a stylized gripper that moves, gradients, distances, deflections) In addition, it is conceivable that the force acting on the end effector can also be represented on the display. This would lead to an "augmented reality".

- Another component of the teleoperation system is a master, which is connected to the remote slave. The connection can be made by radio or cable. The master has at least one operating unit, on which a user can exercise a gripping force F _G. In general, the includes

Control unit Two control devices that are used for the right and the left hand. With these control units can

Movements are performed, which are usually executable in several dimensions. The gripping with the end effector with the gripping force F _G is usually carried out by a pressure with the fingers on a pressure range in the operating means of

Operating unit is formed, wherein the gripping force or

Information of the gripping force is transmitted to the slave.

Further, the master includes a visual user interface that displays the image of the camera and thus allows feedback. The information of the gripping force is first transmitted to the control computer. The control computer converts the gripping force depending on the given mathematical relationship into one

Aperture default for the end effector, and sends it to the slave.

In the device, it should be noted that F _{G is} linearly dependent on the closing angle / a kinematic coordinate and

F is the _effector . That is, the closing angle is determined by the gripping force on the operating means and by the force which is determined at the end effector. The larger both forces are, the smaller the angle between the two grippers of the end effector. In particular, the larger the ratio between the two, the greater the closing angle. On the pseudo-haptic perception of the am

End effector acting interaction force is required in the Control unit therefore no active actuator component that causes a Feedbac.

In another embodiment, _{effector is} determined by one or more of the following approaches:

Derivation of the force from reference variables and / or control parameters as well as model assumptions of the drive unit in the slave

- Measurement of the current in the drive unit

- Measurement of the force in a kinematic structure between end effector and drive unit. This can e.g. Be struts or guide rods or joints.

- Structure-integrated measurement in components of the slave, which derive forces of the end effector. This can e.g. Warehouse or

Be housing parts.

- Through structure-integrated force sensors in one

parallel kinematic manipulator that measures forces and moments in the struts and / or bearing reaction forces in the joints of the parallel kinematic structure. This can e.g. be detected uniaxially in the struts or in one place multidimensional.

- Force / torque sensors on the drive unit. This can be done in front of and behind the gearbox - measuring the force directly between the end effector and the surrounding tissue through sensors attached surface-to-edge or point-by-point to the branches of the end effector

In one possible embodiment, the operating unit

In particular, the operating means as rigid as possible and has only the necessary flexibility for gripping force detection. The user interface should be rigid in order to obtain the following advantages (do not allow deflection in the pseudohaptic degree of freedom)

• No loss of dynamics when transmitting active

haptic feedback of the other degrees of freedom.

• Very good connection of "highly dynamic" feedback in the

rigid operating means.

• No movement of the fingers and thus loss of liability of the

User at the control panel. The operating means can also be designed with constant compliance and thus for a defined deflection. This may provide better (more realistic) results for the degree of freedom of the pseudo-haptic feedback, but will lose the previously described benefits to the overall system.

In a further embodiment, the determination of the gripping force F _{G is} effected by deriving the interaction force between the operating means and the user by one or more of the following methods:

• Simple force measurement between the fingers

• Differential force measurement between the fingers.

This leaves the independence between gripping force

(pseudohaptic feedback) and any active haptic feedback of other degrees of freedom. The differential force measurement is achieved by measuring the gripping force for the thumb and forefinger separately. (In practice, the smaller one will probably be the larger of the two measured values for the

If one measures the differential force of the thumb and forefinger separately, the parasitic forces can be calculated out by external feedback and you only have the forces between your thumb and forefinger. Differential force measurement thus enables a measurement of the force independent of disturbance variables. Disturbances are in this

Related additional forces for e.g. spatial feedback can be coupled.

• From the deflection, deformation of a non-rigid

Operating means.

It follows essentially that at

The teleoperation system can have one of the following dependencies, where

F _G = kinematic coordinate * F _effector Or

F _G = Kinematic coordinate + F _e f _fector

or

F _G = Kinematic coordinate * (F _e _fector + F _min ) + F _G _ _offset Where F _{min is} the force to initially move the effector, and F _G offset is the force to address the sensor in the control unit to let. Other dependencies, in particular linear, are also conceivable. It should be noted that the formulas are intended to represent only the fundamental dependence. Here, alternative parameters can be taken into account that are not yet included here. These include scaling factors of the individual forces as well as scaling factors for adapting the units in the equation and adapting them to any one

kinematic coordinates. The kinematic coordinate may be represented among others by the closing angle of an end effector.

For the purposes of the invention, all mathematical relationships between gripping force F _G and kinematic coordinate of

Endeffektors their purpose, in which an increase in the effective end effector interaction force leads to a greater necessary gripping force of the user to cause a further increase in the kinematic coordinate.

In this case, the selected relationship and the scaling factors are to be selected as a function of the environment manipulated by the end effector.

Pseudohaptic feedback works up to a frequency of about 10 Hz. This barrier results from the ability of man himself to consciously apply forces and movements up to this

To spend frequency. (DIN EN ISO 9241 910). This mainly serves the haptic kinesthetic sense channel.

For frequencies beyond that, tactile haptic feedback can be output. For this purpose, an actuator in the

User interface are used, which couples a directed or undirected haptic feedback to the user.

(Frequency range approx. 50 Hz - 1000 Hz according to DIN EN ISO 9241 910). This allows information regarding material selectivity,

Surface structures, etc. are shown.

In another embodiment, a unit for generating a tactile haptic feedback on the operating unit or operating means is used, wherein a signal is detected by a sensor in the slave, which is sent to the unit for generating a tactile haptic feedback, the spectral components This signal is preferably in the range of up to 50-1000 Hz.

The output of the previously described tactile haptic feedback can be done by:

1. Force output by Inertialmassemotoren

2. Exzentermotoren

3. Piezo actuators - Directly between the operating unit and

operating means

4. Piezo actuators - Between the base of the operating means and the fingers

5. Piezo actuators for generating surface waves

any position of the operating means

This can on the one hand controlled force variables, or

Accelerations are represented.

In a further embodiment, the above-mentioned elements are designed such that the acting force direction of the unit for generating a tactile haptic feedback exert no or only minimal forces in the direction of the gripping force F _{G in} order to reduce control-technical instabilities in the system.

In one embodiment, when introducing such a feedback, attempts are made to remove the forces and deflections output from the actually acting direction of force in order thus to open the control loop and thus control technology

To reduce instabilities in the system. You can also use the position preset signals depending on the output

"Notch filter""high-frequency" tactile output sizes (Narrow-band filters or notch filters) in order to obtain the control engineering stability in the haptic system. By using a notch filter, a narrow-band elimination of a certain frequency is possible. This can be adapted adaptively to the frequency of the tactile feedback. In one embodiment, the position command signals may also be filtered by a low pass filter having a cutoff frequency below the typical tactile feedback frequencies, eg, 40 Hz, to thereby separate the frequency ranges of the channels.

In one embodiment, the sensor is in the slave

Acceleration sensor. Aiternativ encoder signals of the

Actuators are used. High-frequency signals can also be derived from force sensors that have already been described. One could also imagine using surface acoustic wave (SAW) sensors to detect surface vibrations in the kinematic components or at the end effector.

Another part of the invention is the construction of the slave for a teleoperation system, e.g. as described above. Of course, the slave can also be used for other systems and is not limited to a teleoperation system and vice versa. Components can also be used in other combinations

The slave includes

- At least three arranged as tripod push rods, each having two active degrees of freedom in the form of translation and rotation, and by a drive in each of the

Degrees of freedom are driven. It can also do more

Push rods may be possible, even their arrangement can

be different;

- An end effector, which is respectively connected via kinematic chains to the push rods, wherein the kinematic chains are formed so that the end effector is alignable in three dimensions and is obvious and closable, by translation or rotation of the push rods. In one possible embodiment, there is a kinematic chain which is formed as a main chain whose rotation leads to a rotation of the end effector and whose displacement leads to a displacement of the end effector.

In addition, there are two chains which are formed as side chains, the displacement of which leads to a displacement of the end effector, and whose rotation leads to an opening or closing or bending of the end effector.

In one possible embodiment, the rotations of the

Side chains over a spindle and a slide in one

Reshaping linear motion that opens or closes or angles the end effector.

The kinematic main chain preferably has four degrees of freedom and / or the kinematic side chain preferably six degrees of freedom.

The secondary chain is preferably connected to the main chain or its push rod via pivot joints, wherein the rotary joints are formed as U-shaped clasp elements.

In sum, cheaper, more robust and more easily sterilizable systems can be developed with the invention. Here, the use of pseudo-haptis hern feedback in

Teleoperation systems in terms of regulatory stability advantages over conventional haptic teleoperation on.

figure description Fig. 1 shows the structure of an exemplary teleoperation system based on a master-slave structure;

Fig. 2 shows the system structure of a conventional one

Tele-operation system;

Fig. 3 shows the system structure of a "pseudohaptic" system;

Fig. 4 shows the system structure of a combined

Teleoperation system impedance-admittance structure and an additional pseudohaptic degree of freedom and a structure for superimposing high-frequency haptic feedback;

Fig. 5 shows an end effector with different positions of the gripping arms;

Fig. 6 shows an end effector with fully opened gripping arms;

Fig. 7 shows an end effector with partially closed

Gripping arms;

Fig. 8 shows an end effector with completely closed

Gripping arms; Fig. 9 shows an end effector without force between the

Gripping arms, as there is no tissue contact yet;

Fig. 10 shows an end effector with acting end effector

Gripping force on tissue contact;

Fig. 11 shows a control means designed as rigid in the master and the direction of the gripping force under the intervention of the user;

FIG. 12 shows an operating means designed with defined compliance as well as the direction of the gripping force under the intervention of the user; FIG. Fig. 13 shows the relationship between gripping force and

Closing angle without influencing the coupling characteristic by the acting end effector force. Characteristic 1 and characteristic two differ by the predetermined force F _min ;

Fig. 14 shows, in contrast to Figure 13, the relationship between gripping force and closing angle from an optionally usable offset the gripping force; Fig. 15 shows the haptic perceivable gripping force difference with visually perceived same Endeffektorschließwinkel by varying the coupling characteristic between gripping force and

Closing angle; 16 shows an exemplary characteristic curve with the influence of different acting end effector gripping forces on the basis of the multiplicative evaluation of the relationship between gripping force and closing angle with the acting end effector gripping force. FIG. 17, unlike FIG. 16, shows the characteristic curve

Influence of different end effector gripping forces on the basis of the additive evaluation of the relationship between gripping force and closing angle with the acting end effector gripping force. Fig. 18 shows the embodiment of the slave consisting of

End effector 1, TCP 2, parallel kinematic mechanism 3,

Push rods 4, camera channel 5, shaft 6 and drive unit 7;

19 shows an enlargement of the embodiment in FIG. 18 with end effector 1, TCP 2, parallel kinematic mechanism 3, FIG.

Push rods 4, camera channel 5, shaft 6;

Fig. 20 shows the embodiment of a Bedienmitteies with

Operating means 1, TCP of operating unit 2, base 3, operating means 4 drives; 21 shows the embodiment of a rigid operating means with gripping elements 1, 2, fingers 3, base 4 of the operating means,

Fastening element 5 for attachment to the TCP of the operating means, force sensor elements 6 between handle elements and base of the operating means;

22 shows a section and the exploded view of the embodiment of an operating means with handle elements 1,

Actuators for tactile feedback 2, force sensor elements 3, base of the operating means 4, fastener for TCP of

Operating means;

Fig. 23 shows a detailed structure of the slave.

Description of the embodiment:

The invention will be described below with reference to a teleoperation system for minimally invasive surgery, which is not

is to be understood as limiting. This transmits

Control information of the user to an intracorporeal

Manipulator and provides the user with the interaction forces between the end effector of the intracorporeal manipulator and tissue as a haptic and pseudo haptic feedback on the control unit.

Figure 1 shows the structure of a beispielari see

Teleoperation system based on a master-slave structure with master 1, operating unit 2, operating means 3, visual

User interface (screen 4), parallel kinematic mechanism 5, end effector 6, Tool Center Point 7, working channel 8, camera channel 9, slave 10, operating table 11.

The slave is shown in FIG. It consists of a parallel kinematic mechanism on whose TCP an end effector is mounted. The position of the TCP and thus the position of the end effector can be adjusted by the defined longitudinal displacement of the push rods. The individual push struts become moved by separate actuators in the drive unit. The shaft of the slave contains a channel for a camera and a working channel. The end effector consists of two gripping arms between which the end effector gripping force ( _effector F) acts. Of the

Locking angle (Phi) is the angle between the two gripping arms of the effector. Both the acting force (F _effector ) and the closing angle (Phi) are thus determined resp. detected . In addition to the force between the end effector grippers ( _effector ), the interaction forces between the end _effector and the environment are derived. With a suitable cable is the slave with the

Master connected.

Figures 2 and 3 show, by comparison, the difference of a conventional system from the system of the present invention. It can be seen here that feedback on actuators is not given in the present invention. Fig. 4 shows the

System structure of a combined teleoperation system impedance-admittance structure as well as an additional pseudohaptic degree of freedom and a structure for the superposition of

high-frequency haptic feedback. Here, the systems of Figures 2 and 3 have been merged.

The master consists of two control units according to FIG. 20 for the left and the right hand. These operating units have a

Operating means according to the figures 11, 12, 20, 21, 22 on. Of the

User acts via the control unit with the operating unit. The

Operating means is connected to the control unit at the TCP of the kinematics of the operating unit. By user input into the operating means and thus in the operating unit control signals for the slave are entered into the system. By mounted in the base of Bedienmitteies actuators can be a haptic feedback with respect to the

Slave measured between end effector and environment

Interaction forces generated and output via the control means to the user.

FIG. 18 shows an embodiment of the slave consisting of end effector 1, TCP 2, parallel kinematic mechanism 3, Push rods 4, camera channel 5, shaft 6 and a drive unit 7.

FIG. 19 describes an enlargement of the embodiment in FIG. 18 with end effector 1, TCP 2, parallel kinematic

Mechanism 3, push struts 4, camera channel 5, shaft 6.

Fig. 20 shows the embodiment of a Bedienmitteies with

Operating means 1, TCP of the operating unit 2, base 3 and the drives of the operating unit 4.

21 shows the embodiment of a rigid operating means with gripping elements 1, 2, fingers 3, base 4 of the operating means,

Fastening element for fastening 5 to the TCP of the operating means on the operating unit, force sensor elements 6 between handle elements and base of the operating means.

As a control variable for the closing angle phi of an intracorporeal

End effector (see, e.g., Figures 6 to 17) is used instead of

Position measurement of moving elements of the operating means uses the gripping force of the user. For this purpose, a force sensor system for detecting the gripping force is used in the operating means (for example, see FIGS. 12 and 22). The behavior of the end effector in the form of a (linear) characteristic phi (F _G ) can be influenced and _{adjusted in accordance} with the _{situation by} setting the necessary gripping force F _{G;! Riax} for completely closing the end effector (FIGS. 13-17). A haptic sense impression is created by the correlation of gripping force applied in the user interface and the visually perceived closing angle of the end effector. See the Fig. 7-9.

To generate the haptic feedback no actuator is necessary in this case, since the user generates by his gripping force necessary for a haptic sensory impression force itself.

A necessary prerequisite is a direct view of the end effector by the user. The basic operation this "pseudohapti see feedbacks" is known in the field of virtual reality.

The force F _G or F _grei f is determined as shown in Fig.1 1, 1 2 shown on the operating means.

In order to ensure a haptic feedback of a material in the end effector / gripper, the characteristic curve (FIGS. 13-17) can be varied, which represents the relationship between gripping force on the user interface and the closing angle of the end effector (see FIGS. 5-1 0).

This happens depending on the force needed to close or actuate the end effector. This corresponds to the interaction force due to the equilibrium of forces

^ effector ·

The variation of the characteristic curve phi (F _G ) is possible by addition of the measured output end effector force phi '= phi (F _G + F _e f _fector ) and by multiplication of the measured final _{effective force} phi' = phi (F _G F _e f _fector ). The two cases describe a different weighting of the respective acting

Final effect force (Feffektor). In both cases, the necessary changes

Gripping force, which is necessary to reach a certain closing angle phi. In connection with the visual feedback on the opening of the gripper, this gives the user an impression of the nature of the material on the end effector, since the

Interaction force F _e _{fector is} material _dependent among other things.

FIG. 16 shows an exemplary characteristic curve with the influence of different acting end effector gripping forces on the basis of the multiplicative evaluation of the relationship between gripping force and closing angle with the acting one

End effector grasping force. Characteristic 0 shows the course of the

Coupling without acting end effector gripping force. Characteristics 1 and 2 show the course of the coupling characteristic for gripped materials of different stiffnesses. Characteristic 3 shows the course of a characteristic in the case of the end effector gripping force maximum possible power of action is so high that the

Actual variable for the closing angle goes into saturation.

FIG. 17 shows, in contrast to FIG. 16, the characteristic curve when different end effector gripping forces are influenced on the basis of the additive evaluation of the relationship between gripping force and closing angle with the acting end effector gripping force. The

Characteristic 2 describes the engagement on a stiffer compared to characteristic 1 material;

Preliminary tests show that coupling of gripping force and kinematic component via multiplication provides the better results and thus makes it easier for the user to differentiate between different material properties. In addition, it can be seen that the scaling factors and the calculation method can be chosen depending on the nature of the environment of the end effector to control the dynamics of the end effector

haptic perception for distinguishing special

Material parameters optimally exploit.

Necessary requirement for this procedure is the derivation of the interaction force F _effector between the gripping arms of the

End effector (Figs 9-10). The dynamic demands on these measurements are low, since the human ability to exercise has only a small, almost quasi-static bandwidth. Therefore, the derivation of the force efficiencies of the actuators and in the end effector by the integration of a sensor away from the end effector is sufficient. This not only reduces the dynamic requirements, but also the requirements for installation space, weight and overload resistance of the possibly used sensor.

The haptic feedback of the gripping force is shown in this way

quasi-static and therefore to the representation of certain

Properties such as surface texture and differentiation of materials may not be sufficient. Therefore, in a further embodiment, this disadvantage can be easily compensated by the integration of a highly dynamic actuator in the operating means (piezo, voice coil, eccentric motor, etc.) with very small necessary deflections. By the properties In human haptic perception, the introduction direction is not well distinguishable for highly dynamic signals, so here is a haptic feedback perceived in several degrees of freedom with a one-dimensional movement of the actuator

can be represented.

Actuators for tactile feedback 2, force sensor elements 3, a base of the operating means 4 and a fastener for TCP of the operating means;

The measurement of high frequency signals could be made by measuring accelerations with miniaturized, sterilizable in

End effector arranged acceleration sensors happen.

In comparison of known from the literature

Teleo tion systems with haptic feedback can not only be extended pseudohaptically executed degree of freedom of the haptic perceptible area with the invention presented here but also the design effort of the entire operating means can be reduced. By using serially arranged actuators, a frequency distribution for the haptic feedback is possible, Instead of a large bandwidth actuator with large necessary deflections in the base of the operating means of the high-frequency portion of the haptic feedback is generated by a dynamic actuator with small deflections. In the end effector, the expense of the sensor system is reduced to the effect that multidimensional, highly dynamic force sensor system by a one-dimensional force sensor and a mehrdimensiona

Acceleration measurement could be replaced. The latter is easier to integrate into the end effector since it does not have to be integrated in the main force flow direction. In addition, peripheral sensor requirements in terms of dynamics, overload resistance and sterilizable packaging are decreasing. FIG. 23 shows one of two parallel kinematic mechanisms of the slave, which will also be referred to below as a manipulator. Each manipulator has up to six degrees of freedom, so that the TCP 1 can be positioned in the room. Furthermore, an end effector 2 fastened to the TCP can be rotated about its longitudinal axis 3, angled (Abw) and its closing angle (Phi)

to be changed.

The parallel kinematic mechanism consists of kinematic chains composed of rigid or flexible struts and joints. In general, for the realization of the

Joints a variety of solutions conceivable. Thus, in addition to rigid joints and solid joints or flexible elements such. Springs, film hinges, bellows and NiTi wires are used. In order to move the intracorporeal manipulator, are in the extracorporeal drive unit per manipulator

vorzusgsweise six engines attached. Another number of motors and gears is conceivable. The movements generated are transmitted via three push rods 4 in the intracorporeal area. Two active degrees of freedom in the form of translation ql0-q30 and rotation q40- q60 are transmitted via a push rod. The movements provided intracorporeally are reshaped by the parallel kinematic mechanism, which consists of a kinematic main chain 18 and up to four kinematic side chains 8, 9, 14, 15 such that a displacement of the push rods leads to a change in position of the TCP, a rotation of the main chain q40 rotates the end effector around its longitudinal axis at will and a rotation q50 and q60 opens or closes and angles the gripper. This is e.g. achieved by corresponding spindles, which are also visible in FIG.

In detail, the parallel kinematic mechanism consists of a tripod-like substructure, which results from the kinematic structure

Main chain 18 with four degrees of freedom and two kinematic side chains 8, 9 composed of six degrees of freedom. These kinematic chains are connected to the main shaft 5 via hinges. In order to prevent jamming, these joints are realized as U-shaped clasp elements 6, 7. The rotation of the The main chain is forwarded directly to the end effector via a universal joint at the base so that it can be rotated arbitrarily about its longitudinal axis.

The rotations of the two remaining push rods are also continued via universal joints along the first and second

Transfer side chain and finally converted via a spindle and a slide 10, 11 in each case a shift. Via the third and fourth side chains 14, 15, which each have four

Degrees of freedom, these movements are transmitted to sleds guided with respect to the main shaft 21, 22. To the

Within the mechanism, limiting forces are integrated in the third and fourth side chains. To prevent jamming of the carriage elements, they are also designed as a U-shaped clip. The occurring within the hinges 12, 13 friction torque is on the

Side chains dissipated. For this purpose, the clasp elements 6 and 7 are connected via a respective pendulum support with the elements 21 and 22 respectively.

Each of the displacements generated on the main shaft moves a push rod within the main shaft, this movement being directed onto either one of the two jaws of the end effector, e.g. by means of a

Cam or a bell crank 16, 17 is transmitted. The push rods are guided over a slot with respect to the main shaft and locked against rotation by means of a pin. To maintain the rotation of the main shaft, the am

Main shaft generated slide movements 21, 22 via pivot joints 12, 13 transmitted to the push rods located in the shaft. Consequently, the gripper can be opened or closed via a rotation in the same direction q50 and q60. Rotate the

Push rods opposite, so the gripper is angled.

The described situation is invertible.

The described parallel kinematic mechanism has the following transmission properties:

1. The position of the TCP is independent of the rotations q40- q60 and becomes alone from the shifts ql0-q30

influenced. 2. The push rods are arranged colinear, so that the

Working space in the z-direction is limited only by the maximum travel of the push rods. In the z-direction results in a constant gear ratio of 1.

3. The longitudinal rotation of the end effector is solely by the

Rotation q40 dependent.

4. The opening angle and the angle are mainly determined by the rotations q50 and q60.

In order to reference the kinematics with respect to the base plate (19), stops (20) are attached to the ends of the push rods.

The invention is not limited to the embodiments described above, but should be determined by the claims.

Claims

claims

Teleoperation system comprising:

- A slave (10) having a drive unit which drives a cross-end effector, wherein a

kinematic coordinate of the end effector and a

Gripping force F _{effector is} determinable

- With a camera (9), preferably in the slave

integrated, and which is aligned with the end effector,

a master (1) remotely connected to the slave, with at least one operating unit (2, 3) on which a user can exert a gripping force F _G , the

Gripping force is transmitted to the slave, and with a visual user interface (4) representing the image of the camera,

where F _{G is} linearly dependent on the kinematic coordinate and F _effector or vice versa.

The teleoperation system of claim 1, wherein the _{effector is} determined by one or more of the following approaches:

Derivation of force from reference quantities of

Drive unit in the slave or from a control computer

- Measurement of the current in the drive unit;

- Measurement of the force in a kinematic structure between end effector and drive unit;

- Structurally integrated measurement by force sensors in a parallel kinematics;

- Force / torque sensors on the drive unit;

- Measurement of force directly between end effector and surrounding tissue. The teleoperation system according to claim 1 or 2, wherein the operating unit is as rigid as possible and has only the flexibility necessary for gripping force detection. The teleoperation system according to claim 1 or 2, wherein the operating unit has a defined compliance and is thus designed for a defined deflection and thereby enables gripping force detection, whereby an actuator in the operating unit can be dispensed with.

The teleoperation system according to one or more of the preceding claims, wherein the determination of

Gripping force F _{G is} achieved by deriving the interaction force between the operating unit and the user by one or more of the following methods:

- Force measurement between the fingers

- Differential force measurement between the fingers

- Derivation of the force from the deflection or deformation of a non-rigid operating unit.

The teleoperation system according to one or more of the preceding claims, wherein

F _G = Kinematic coordinate * F _e f _fector

Or

F _G = Kinematic coordinate + F _e f _fector

or

F _G = Kinematic Coordinate * (F _e f _fector + F _min ) + F _G _ _offset Where F _{min is} the force to initially move the effector, and F _{G 0} ffset is the force to respond to the sensor in the control unit and preferably possible factors for scaling the forces to adapt the relationships described to any

Textures of the manipulated environment.

The teleoperation system according to one or more of the preceding claims, characterized by a

A unit for generating a tactile haptic feedback on the control unit, wherein a frequency is detected by a sensor in the slave, the to the unit for

Generation of a tactile haptic feedback sent is preferably in the range of up to 50 - 1000 HZ.

The teleoperation system of the preceding claim, wherein the tactile haptic feedback generating unit is one or more of the following:

- Force output by Inertialmassemotoren

- Exzentermotoren

- Piezoelectric actuators

The teleoperation system according to one or more of the preceding two claims, wherein the operative one

Force direction of the unit for generating a tactile haptic feedback exercise no or only minimal forces in the direction of Greifkaft F _G to order

control-technical instabilities in the system too

to reduce .

The teleoperation system according to one or more of the preceding three claims, wherein the frequency detected by a sensor in the slave is filtered in response to ambient values to obtain stability in a control loop.

The teleoperation system according to one or more of the preceding four claims, wherein the sensor in the slave is one or more of the following:

Acceleration sensor, encoder signals of the actuators,

Derivation of high-frequency signals from the force sensors, "surface acoustic wave" (SAW) sensors for detecting surface vibrations in the kinematic components or at the end effector.

The teleoperation system according to one or more of the preceding claims, wherein in the camera image an additional digital representation of the current

Endeffektorkoordinate is superimposed, preferably by one or more of the following:

Angle indication, lines that move on each other, A Stylized Gripper that moves, displays color gradients, shows the force acting on the end effector on the display, deflection.

The teleoperation system according to one or more of the preceding claims, wherein a control computer is configured to perform a differential force measurement on the control unit by measuring the thumb and forefinger gripping force separately, and preferably the smaller or larger of the two measured gripping force values selects.

A slave for a teleoperation system, preferably according to one or more of the preceding claims, comprising:

- At least three arranged as a tripod push rods, each having two active degrees of freedom in the form of

Translation and rotation, and by a

Drive be driven in each case in the degrees of freedom;

- With an end effector, which is respectively connected via kinematic chains with the push rods, wherein the kinematic chains are formed so that the

End effector is alignable in three dimensions and is obvious and closable, by translation or

Rotation of the push rods.

The slave of claim 14, wherein a kinematic chain is formed as a main chain, the rotation of which leads to a rotation of the end effector and their displacement leads to a displacement of the end effector.

The slave according to one of claims 13 to 14, wherein two chains are formed as side chains, whose

Displacement leads to a displacement of the end effector, and its rotation leads to an opening or closing or angling.

The slave according to the preceding claim 16, wherein the rotations of the side chains are converted via a spindle and a slide into a linear movement which opens or closes or angles the end effector.

18. The slave according to one of claims 13 to 17, wherein the kinematic main chain has at least four degrees of freedom and / or the kinematic side chain at least six degrees of freedom.

19. The slave according to any one of claims 13 to 18, wherein the

Side chain is connected to the main chain via hinges, wherein the hinges are formed as U-shaped clasp elements.