Robot system and control method for a robot system

Abstract

The present invention relates to a medical robot system (1) for an adapted control of an end effector (8), in particular for controlling a visualization unit, during a procedure on a patient, having a robot (2) with a movable robot arm (4) and the end effector (8), which is arranged on the robot arm (4) and is movable by the robot arm (4); having an input unit (10), in particular a joystick with a deflection angle from a zero position serving as an input signal, for a user to input an input signal to the robot (2); and having a control unit (12) which is adapted to control, based on the input signal, the movement of the robot arm (4) and thus, in particular, the position and / or orientation of the end effector (8). In order to control the movement of the end effector (8), the control unit (12) is adapted to convert the input signal by means of a non-linear control curve into a control signal of a speed specification of the end effector (8) in a specified direction. The present invention further relates to a control method for a medical robot system (1), a computer-readable storage medium and a computer program according to the additional independent claims.

Description

[0001] Robot system and control method for a robot system

[0002] Description

[0003] Technical area

[0004] The present disclosure relates to a medical robot system with or for an adapted control of an end effector, in particular for a control of a visualization unit as an end effector, during a procedure or examination on a patient. The medical robot system has (at least) one robot with a movable robot arm and an end effector that is connected to the robot arm (and thus arranged), for example articulated, and can be moved by the robot arm. Furthermore, the robot system has an input unit, in particular a force-sensitive (i.e. dependent on a manually applied force), in particular a joystick with a deflection angle (in response to the applied force) from a zero position orZero axis as an input signal, for inputting an input signal to the robot by a user (wherein the input unit provides continuous or discrete-continuous input signals between zero and a maximum input of the input unit); and a control unit adapted to control the movement of the robot arm, and thus in particular the position and / or orientation of the end effector, based on the input signal. In addition, the present disclosure relates to a control method for a robot system, a computer-readable storage medium, and a computer program according to the preambles of the independent claims.

[0005] Technical background of the revelation

[0006] Particularly in medical applications of robotic systems, such as a surgical robot or a robot-assisted visualization system, precise end-effector guidance by means of a precise robot control is necessary, since (spatial) inaccuracies of the end-effector endanger both the patient and the success of the medical procedure.

[0007] With known surgical robots or robot-assisted

[0008] In visualization systems, an end effector, for example a visualization unit such as a surgical microscope, is moved and spatially arranged by a robot arm. The robot arm can, for example, be movably attached to a robot base, which is a movable medical cart to which the movable robot arm is hinged. The visualization unit can be spatially positioned or arranged by the robot arm. The robot arm can be controlled by the user using buttons, a lever, or by manually moving the end effector to a desired position. For example, the robot arm is controlled using the deflection angle of the lever, such as a joystick, as an input signal. However, this creates a conflict of objectives between precise control behavior, which inevitably entails a slow (travel) speed of the robot arm and thus of the end effector, and an acceptably fast end effector speed.Especially when the end effector has to be moved from one position to another, a too slow...

[0009] End-effector speed may be undesirable for a user. This increases the operating time and also causes surgeon fatigue.

[0010] From US 6424 338 B1 a touchpad is known in which a cursor control on the touchpad is varied depending on a position of an operating finger. In particular, the speed or acceleration of the cursor on a screen can be increased if the finger touches the touchpad in an edge region of the touchpad.

[0011] WO 2010 / 088 959 A1 discloses a method for controlling an industrial robot. The robot has a mode in which the user can manually move the robot into various positions and postures. A control unit of the robot stores these manually controlled positions and travel paths, allowing these stored positions to be moved to later automatically. However, the method of WO 2010 / 088 959 A1 does not allow for precise control of specific desired positions and / or orientations of the end effector.

[0012] The publication "Performance and Usability of Various Robotic Arm Control Modes from Human Force Signals" - Mick et al., Frontiers in Neurorobotics, October 2017, Vol. 11, Article 55, describes a relationship between a force as an input signal and a prosthetic movement as an output signal. Test participants perceived a quadratic relationship between the input force and the prosthetic movement as preferable to a linear or proportional relationship.

[0013] Summary of Revelation

[0014] It is therefore the object of the present disclosure to overcome or at least mitigate the disadvantages of the prior art and, in particular, to provide a medical robot system, a control method, a computer-readable storage medium, and a computer program that enables the most intuitive and precise control of the robot system by a user. In particular, precise fine control and rapid coarse control of the robot system, in particular of the end effector, should be enabled.

[0015] These objects of the present disclosure are achieved according to the invention with regard to a medical robot system by the features of claim 1, with regard to a medical control method by the features of claim 13, with regard to a computer-readable storage medium by the features of claim 14 and with regard to a computer program by the features of claim 15.

[0016] The present disclosure relates to a medical robot system for adapted or optimized control of an end effector, in particular for controlling a (robot-assisted) visualization unit such as a surgical microscope as an end effector, during an intervention on a patient. The medical robot system comprises a robot with a movable robot arm and an end effector connected to the robot arm and movable by the robot arm (spatially adjustable in its position and orientation), and an input unit for inputting an input signal to the robot by a user. The input unit is adapted to output continuous or discrete-continuous input signals between zero and a maximum input based on the input. The input unit is in particular a joystick with a deflection angle from a zero position or zero axis as the input signal.The medical robot system further comprises a control unit adapted to control the movement of the robot arm, and thus in particular the position and / or orientation of the end effector, depending on / based on the input signal. The control unit is adapted to convert / process / convert the input signal into a control signal specifying the speed of the end effector in a specified direction using a (stored or calculated) nonlinear control curve in order to control the movement of the end effector.

[0017] The input unit, in particular the joystick, can preferably be deflected by the user in various directions from a preferably vertical zero / starting position. The deflection angle can be detected by the control unit. The deflection angle can, in particular, be converted into an electrical signal that represents an input variable or the input signal for the control unit.

[0018] The control signal can be a specification to the robot in which a (target) speed of the end effector is specified. This speed specification can further be converted by the control unit into a manipulated variable for the individual actuators of the robot arm. The control unit is adapted to calculate the control signal as a function of the input signal. The control signal can in particular be a set of control currents or frequency changes in the current applied to the (electrical) actuators of the robot. In other words, there is a predetermined relationship between the detected input signal of the input unit and the output control signal. The predetermined relationship can be stored as the control curve in the control unit. A change or a derivative of the control curve should not be constant in order to realize the non-linear relationship between the input signal and the control signal.The predetermined relationship can further be a formula according to which the control unit converts the input signal into the control signal. Preferably, the predetermined relationship can be an amplification or reduction of the input signal. The control signal can therefore be calculated by multiplying the input signal by a (varying) factor. This factor should not be a constant, which would result in a constant amplification or reduction of the input signal across the deflection angle. However, the factor can, in particular, be dependent on the magnitude of the input signal. This allows the non-linear relationship between the input signal and the control signal to be realized.

[0019] In particular, the input unit can be the joystick with the deflection angle as the input signal. The control unit can convert the deflection angle into the speed specification for the end effector. The speed specification can determine how fast the end effector is moved by the robot arm. The (moving) speed of the end effector should, in particular, be non-linearly dependent on the size of the deflection angle.

[0020] The robot can be controlled, in particular, in Cartesian space. The input unit can control the movement of the end effector in the translational and rotational directions.

[0021] The speed specification in the specified direction can, in particular, be a translational direction of the end effector in the form of a specified speed vector of the end effector (y_x, v_y, v_z). Alternatively or additionally, rotational direction(s) can also be specified as specified direction(s), for example r^_x for a rotation around the x-axis, cy for a rotation around the y-axis, and r_z for a rotation around the z-axis in the Cartesian coordinate system, whereby the speed specifications can represent the rotational speeds v_rx, v_ry, v_rz. The robot is then controlled accordingly by the control unit so that the control signal is converted into the corresponding movement. In particular, the robot arm can also be controlled in addition to the end effector.

[0022] A basic idea of ​​the present disclosure is therefore that the input signal which is input into the robot system by the input unit is non-linearly, in particular over- or under-proportionally, linked or coupled to the control signal.

[0023] Thanks to the adapted, non-linear control curve, the robot system has particularly advantageous control behavior, namely both with a low input signal and with a high input signal from the input unit, and in particular with small and large deflections of the joystick. In particular, the robot arm and thus also the end effector can be precisely controlled even with small deflections. At the same time, rapid movement of the end effector can be achieved even with large deflections. This means that the robot arm, and in particular the end effector, can be precisely controlled when necessary, and quickly moved when fast movement is desired by the user. Overall, the robot system can in particular provide coarse and fine control, or a mode with fine control and a mode with coarse control.

[0024] It may also be advantageous that the user does not have to switch manually between different modes, but that the control unit automatically sets the desired mode.

[0025] The object of the present disclosure is further achieved by a control method for a medical robot system for adapted control of an end effector, in particular for controlling a visualization unit, during an intervention on a patient. The control method has the following steps. An input unit detects an input signal from a user. The input signal is in particular a deflection angle from a zero position of the input unit. The detected input signal is read into a control unit. The control unit calculates a control signal of a speed specification of the end effector in a predetermined direction from the input signal using a (stored) non-linear control curve. On the basis of the calculated control signal, the control unit controls a robot with a movable robot arm and an end effector that is arranged on the robot arm and can be moved by the robot arm.The control method for the robot system disclosed herein allows the robot, and especially the end effector of the robot system, to be controlled both precisely over small-scale movements and quickly over longer distances. In particular, intuitive control is provided for the user.

[0026] In completely different words, a medical, in particular surgical, collaborative robot for actuating a medical, in particular surgical, end effector is proposed, comprising: a robot base as a local connection point of the robot; a movable robot arm connected to the robot base and having at least one robot arm segment; an end effector connected, in particular mounted, to the robot arm, in particular to a terminal side of the robot arm, having an end effector axis, in particular a visualization device having a visualization axis; and a control unit adapted to control at least the robot arm.What is special here is that the medical robot, in particular on its end effector and / or on a robot arm segment, has at least one input means with a, in particular straight, zero axis, which is adapted to detect at least one force (manually) applied to the input means transversely to the zero axis in at least two opposite directions as an input signal and to convert it by means of the control unit and a non-linear control curve into a control signal of a speed specification in a predetermined direction.

[0027] The term "zero axis" defines the zero or rest position of the input device, in which no manually applied (input) force acts on the input device. In particular, the zero axis is a type of symmetry axis of the input device, allowing at least one input in two opposite directions perpendicular to the zero axis. The zero axis serves, in particular, to orient an input from the input device.

[0028] In the present disclosure, the term "end effector" refers to a device, instrument, or similar medical device that can be used to perform a procedure on a patient. In particular, end effectors can be considered to include: an instrument, a medical device such as an endoscope or a suction tube, an optical device with a visualization axis (visualization system), a pointer with a distal tip for surgical navigation, and others.

[0029] The term "position" refers to a geometric position in three-dimensional space, which is specified, in particular, using coordinates of a Cartesian coordinate system. In particular, the position can be specified by the three coordinates X, Y, and Z.

[0030] The term "orientation," in turn, indicates an alignment (e.g., position) in space. One could also say that orientation indicates an orientation with a direction or rotation specification in three-dimensional space. In particular, orientation can be specified using three angles.

[0031] The term "attitude" encompasses both position and orientation. In particular, attitude can be specified using six coordinates: three position coordinates X, Y, and Z, and three angular coordinates for orientation.

[0032] Advantageous further developments of the present disclosure are the subject of the dependent claims and are explained in particular below.

[0033] According to one embodiment of the present disclosure, the nonlinear control curve is a function of the input signal multiplied by the input signal itself. For example, the control curve can be y = A(x)*x, where y is the control signal, A(x) is the function of x, and x is the input signal. The control curve (y or f(x)) can be formed by multiplying the input signal (x) by a gain or attenuation (such as A(x)). This gain or attenuation is not constant but can depend on the detected input signal. In other words, the control unit can calculate an output or intermediate value from the input signal in an intermediate step. This intermediate value can depend on the input signal or be a function of the input signal. The intermediate value can, for example, be formed as a linear function by multiplying the input signal by a constant.The non-linearity of the relationship between the control signal and the input signal is created by the dependence of the intermediate value on the input signal or by the fact that the control curve can be a function of the input signal multiplied by the input signal. The amplification or reduction can therefore be particularly large when the input signal is large and particularly small when the input signal is small.

[0034] Preferably, in a graph with the input signal as the abscissa and the control signal as the ordinate, the control curve lies in a range of less than 20%, preferably less than 30%, and particularly preferably less than 50%, of a maximum input of the input unit, in particular a maximum deflection, below a straight line through the origin with a gradient of 1 or an angle bisector, so that the speed specification is lower for a lower input signal than for a linear control. The input from zero to the maximum input (100%) is plotted on the abscissa, while the control signal is plotted in the form of a speed from zero to the maximum speed (100%) on the ordinate. The control curve thus begins at the origin and ends at a point. With a small input signal, in particular a small deflection angle, only a small movement or slow speed of the end effector in the specified direction is desired.Therefore, the end effector can be moved at low speed. This ensures precise control of the end effector if the end effector is to be moved only slightly and slowly.

[0035] According to a further optional feature of the present disclosure, in a graph with the input signal as the abscissa and the control signal as the ordinate, the control curve lies in a range of more than 70%, in particular more than 90%, of the maximum deflection above a straight line through the origin with a gradient of 1 or an angle bisector, so that the speed specification is greater with a larger input signal. With a large input signal, in particular a large deflection angle, a large movement of the end effector is desired. The end effector is then often to be moved over a greater distance. Therefore, the end effector can then be moved at high speed so that the large desired distance can be covered in a short time.

[0036] Preferably, a derivative or a change in the control curve is (overall) linear or quadratic or at least linear in sections / distances. Since the derivative of the control curve (f(x)) is not constant, the relationship between the input signal and the control signal is non-linear. As a result, the gain or reduction of the input signal increases disproportionately or disproportionately with the size of the input signal. A linear control curve would mean that the gain or reduction of the input signal would be constant over the course of the input signal. However, this would prevent the speed setting of the end effector from becoming particularly large or small depending on the size of the input signal. The non-linear control curve can therefore generate large deflections at the boundary values ​​of the input signal.

[0037] In particular, the control curve can be designed in such a way that low input signals (approximately less than 20% of a maximum input) are converted into disproportionately low movement speeds (approximately less than 10% of a maximum speed) as a control signal in order to ensure precise guidance.

[0038] In one embodiment, the robot system has a touch display, allowing the user to draw their own control curve and store it in a memory unit. This allows the user to generate a customized nonlinear control curve or adapt a sample control curve.

[0039] According to a further optional feature of the present disclosure, two different input signals can be detected by / via the input unit, for example an input signal in a first direction and an input signal in a second direction. In particular, the input unit can be designed as a joystick that can be deflected in at least two directions. Each of the directions can have its own deflection angle from a zero position or zero axis as the input signal. The control unit can be adapted to convert the first input signal into a control signal for specifying the speed of the end effector in a first predetermined direction by means of a first non-linear control curve and to convert the second input signal into a control signal for specifying the speed of the end effector in a second predetermined direction by means of a second control curve, which differs from the first control curve.The joystick, for example, can be deflected in two directions, with one deflection direction causing end effector movement in the vertical direction and another deflection direction causing end effector movement in the horizontal direction. In all deflection directions, the speed setting of the end effector can be calculated from the input signal via the control curve. The influence of the control curve on the different input signals can also vary between the different input signals. The terms vertical, horizontal, top, and bottom can be seen in relation to an operating room. Here, "top" is something like a ceiling and "bottom" is something like a floor, which connects the "vertical" lines. Likewise, the floor of the operating room extends "horizontally."

[0040] Preferably, the input unit, in particular the joystick, is arranged on the end effector, in particular rigidly attached, and the direction of the deflection can specify the direction of movement. This means that the deflection direction of the joystick can specify the direction of movement of the end effector. If the joystick on the end effector is deflected downwards in the direction of gravity, the end effector can move downwards (in the direction of gravity). Likewise, a horizontal deflection of the joystick can cause a horizontal movement of the end effector. The speed of the end effector can depend on the deflection angle of the joystick via the control curve. If the joystick is attached to the end effector, the robot or the end effector can be controlled, in particular in Cartesian space. This can provide intuitive operation or control of the robot by the user.According to a further optional feature of the present disclosure, the control unit is adapted to switch, at least temporarily, between an adapted mode or amplification mode, in which the control curve is applied to the input signal, and a normal mode, in which no non-linear control curve is applied to the input signal. In normal mode, the control signal can be proportional to the input signal. This means that the amplification or reduction of the input signal is not dependent on the input signal in normal mode. For some applications, a constant or linear relationship between the input and control signals can be useful. For example, predictability of the effective end effector movement can be increased in normal mode. The user can therefore vary the control curve at least temporarily or in sections.

[0041] According to a further optional feature of the present disclosure, the control unit is adapted to vary or change the control curve (in real time) during a movement of the end effector and thus adapt it to the current conditions. This means that the amplification or reduction of the input signal can be varied during the end effector movement. This allows the degree of amplification or reduction to be changed and the control behavior of the robot system to be adapted to the individual circumstances or user needs. For example, there may be surgical interventions that require a very precise and small-scale procedure. However, there may also be surgical interventions that require frequent movement of the end effector over greater distances. Depending on the individual procedure, the user can set or vary the control curve.In particular, the user can choose between different modes and thus control curves stored in the control unit in order to select different speed profiles.

[0042] Preferably, the end effector is arranged at a distal end of the movable robot arm and is, in particular, a visualization unit, particularly preferably a surgical microscope, a gripper arm, and / or a trocar. Surgical (operating) microscopes, in particular, are often moved into different positions and / or orientations during the surgical procedure to optimize a viewing angle. Therefore, it can be particularly advantageous for surgical microscopes to disproportionately increase the speed output of the end effector when large input signals are present.

[0043] The joystick as an input unit can not only be deflected from the zero position, but can also be rotated around its axis. This allows, for example, the end effector to be rotated and its orientation to be changed. This means that the end effector can be moved by the robot arm in its spatial position, but also rotated to change the spatial orientation of the end effector and, for example, rotate the end effector around its (longitudinal) axis. The control curve can also be applied to the rotation of the end effector by the control unit.

[0044] The control curve can preferably also be applied to only one degree of freedom of the end effector. For example, the control curve can be applied to the input signal of a translational movement for a corresponding translational control signal, while the control curve is not applied to the control signal of the rotary movement. Alternatively, the control curve can also be applied to the determination or calculation of the control signal of the rotary movement and not to the calculation of the control signal of the translatory movement.

[0045] According to a further optional feature of the present disclosure, the input unit can be a 3D mouse / space mouse, a force and / or torque sensor, and / or another input system that provides continuous or discrete continuous values. This means that any input unit that outputs non-binary values ​​(i.e., not 0 or 1) can be suitable for the robot system. An input unit that outputs only three different values ​​to the control unit is conceivable. In other words, the robot system has an input unit (space mouse) that is at least joystick-like and is attached to the end effector or another section of the robot. Furthermore, the input unit could also be embodied as an external input unit that is not directly connected to the robot.According to one embodiment, a 3D mouse / a (3D) space mouse / a 3D space mouse can be used as the at least one input means, which, in addition to three axis inputs (up / down, front / back, left / right or in XYZ of a Cartesian KOS), also enables three rotational inputs (around each of the three axes), wherein one axis of the 3D mouse, in particular a Z axis, is aligned as the zero axis parallel, in particular coaxial, to the end effector axis and / or the longitudinal axis of the robot arm segment in order to move the end effector (if parallel to the end effector axis) and / or the robot arm segment (if parallel to the longitudinal axis of the robot arm segment) translationally and rotationally (in particular around a focal point or an instrument tip) in accordance with the input. Thus, in one embodiment, a 3D space mouse can be used as a joystick to control the robot.An example of a 3D mouse is the 3Dconnexion SpaceMouse Compact (with Z-axis perpendicular to the support surface).

[0046] Preferably, the input unit is arranged on a robot base, in particular on the movable carriage. The robot base can, in particular, comprise the control unit, a storage unit, and an (external) power supply. The control unit can, for example, comprise a processor, a CPU, or a microprocessor. The storage unit can, for example, be embodied as a hard drive or an SSD.

[0047] Preferably, the feed rate of a tool, particularly at the end effector, of the robot can also be controlled by the control unit via the input unit using the nonlinear control curve. In particular, the speed of a linear or circular movement of the (robot) tool can be controlled by the nonlinear control curve.

[0048] Other systems, in particular those with electric motors as actuators, can also be controlled using the non-linear control curve. The non-linear control curve can, for example, be applied to a movement profile of an electric tool. In particular, in a tool set with different tools, a tool-specific non-linear control curve can be stored in a memory unit for each tool, which is used accordingly when the tool is detected or manually selected by a user (via a touch display, for example). The control unit is therefore particularly adapted in a tool mode to convert the input signal into a corresponding control signal, for example a rotational speed of a rotating, medical tool such as a drill or a cutting movement of actuated scissors, using the non-linear control curve associated with the tool.

[0049] The control curve does not necessarily have to depend solely on the input, in particular the deflection angle of the input unit. The control curve or an amplification or reduction of the input signal can be a function not only of the input signal, but also of other, external factors. For example, a control or movement sequence of the end effector from a previous operation can be recorded and stored by the control unit. If the stored control or movement sequence is subsequently executed automatically, the control unit can make the control curve dependent on the stored movement sequence. In this case, for example, the gain of the input signal can be increased for upcoming movements over a large distance.

[0050] In one embodiment, the control unit can be adapted to also apply the control curve to the movement of the robot arm's joints. In particular, individual joints of the robot arm can be controlled instead of controlling an end-effector movement in Cartesian space.

[0051] According to a further embodiment, the control unit can be adapted to also apply the control curve to a zero-point movement of the robot arm. In this case, the robot arm can be moved without moving the end effector. The control curve can in particular be applied to the individual joints. In other words, the control unit can be adapted to maintain the position and orientation (position) of the end effector while the rest of the robot arm is moved, for example in order to assume a better position for the user and to clear a view. The control unit can carry out the movement of individual joints or the movement of the robot arm itself or its travel speed using the non-linear control curve.In particular, for a small deflection of a joystick attached to the end effector (approximately less than 30% of the deflection), the end effector remains static while the robot arm moves slowly (approximately less than 10% of the speed), whereas for a large deflection (approximately more than 70%), the robot arm changes its configuration and moves quickly (approximately more than 90% of the maximum speed).

[0052] The control curve with the amplification or reduction of the input signal can preferably also be time-dependent. In particular, the amplification or reduction can be greater if the joystick is deflected for a particularly long time. The amplification or reduction can be small if the joystick is only deflected briefly. Especially if the joystick has a large deflection angle for a long time, the amplification or reduction can be large. The amplification or reduction can then be a function of time and the input signal, for example.

[0053] In particular, the robot system has a navigation system.

[0054] The objects of the present disclosure are achieved with regard to the computer-readable storage medium and with regard to the computer program in that they comprise instructions which, when executed by a computer, cause the computer to carry out the control method according to the present disclosure.

[0055] Any disclosure related to the robot system according to the present disclosure also applies to the control method according to the present disclosure and vice versa.

[0056] Short description of the characters

[0057] The disclosure is explained in more detail below using preferred embodiments with the aid of figures. They show:

[0058] Fig. 1 is a schematic perspective view of a robot system according to a preferred embodiment of the present disclosure; Fig. 2 is a schematic view of a graph of a control curve with an input signal from an input unit and a control signal of a movement of the end effector of the robot system of Fig. 1 according to a preferred embodiment;

[0059] Fig. 3 is a schematic view of a graph of a further, second control curve with an input signal of an input unit and a control signal of a movement of the end effector of the robot system according to another embodiment of the present disclosure; and

[0060] Fig. 4 is a flowchart of a control method of a preferred embodiment according to the present disclosure.

[0061] The figures are schematic in nature and are intended only to aid understanding of the disclosure. Like elements are designated by like reference numerals. The features of the various embodiments may be interchanged.

[0062] Detailed description of the characters

[0063] Fig. 1 shows a robot system 1 according to a preferred embodiment of the present disclosure, which is provided for a targeted visual magnification of an intervention area.

[0064] The robot system 1 comprises a robot or a guiding robot 2 with a (movable) robot arm 4 with multiple robot arm segments, which is movably articulated to a robot base 6. The robot arm 2 has an end effector 8 at its end, here in the form of a surgical (operating) microscope, which is movably connected to the robot arm 2 and which can be moved in space via the robot arm 2. The robot system 1 further has an input unit 10 for inputting an input signal to the robot 2 by a user. In this embodiment, the input unit 10 is a 3D mouse (i.e., a type of joystick with additional rotation inputs) that can be deflected in three different directions from a zero position or relative to a zero axis. A deflection angle of the joystick from the zero position in each of the individual directions is the input signal of the input unit 10. The input unit 10 in the form of the 3D mouse is attached to the end effector 8.The end effector 8 follows the deflection direction of the input unit 10, which ensures intuitive operation of the robot 2.

[0065] The robot system 1 has a control unit 12 adapted to control the movement of the robot arm 4, and thus in particular the position and orientation of the end effector 8, based on the input signal of the 3D mouse. The control unit 12 is specifically adapted to convert the input signal into a control signal. Specifically, the control unit 12 controls the movement of the end effector 8 such that the input signal of the input unit 10 is converted into a speed specification of the end effector 8 by means of a non-linear control curve 11 stored in a memory unit in order to control the movement of the end effector 8. This control curve 11 can be stored in the memory unit as a function f(x) (e.g., f(x)=x A2) or as a curve of a graph as such. In particular, this control signal can be present as a velocity vector of the end effector with respect to a Cartesian coordinate system (v_x=1cm / s, v_y=2cm / s, v_z=0cm / s). Robot 1 is then controlled accordingly so that robot arm 2 moves the surgical microscope as end effector 8 with this velocity vector.

[0066] The adapted control unit 12 with the non-linear control curve 11 allows the user to perform a precise, slow movement with a small deflection of the 3D mouse, while controlling a fast movement of the surgical microscope with a large deflection of the 3D mouse. This provides the user with both fine and coarse control. In a variant not shown, a medical tool, in particular a drill, can be provided as an end effector instead of or in addition to the surgical microscope, and the control unit 12 can be adapted to switch back and forth between a movement mode and a tool mode and, in tool mode, to control the rotational speed of the tool (via the 3D mouse) using a stored, non-linear control curve.

[0067] The robot system 1 further comprises a (surgical) display 14 for input and output, thus enabling user interaction with the robot system 1. Information, in particular an image captured by the surgical microscope, can be output to the user via a further output unit 16. Equipped with a navigation system, a camera 18 can detect the position of the end effector 8 and transmit the detected position to the control unit 12.

[0068] Fig. 2 shows a graph that maps a control signal (f(x)) as a speed specification of the end effector 8 as a function of the input signal (x) using the non-linear control curve 11. The control curve 11 is stored in the control unit 12 or a memory unit of the control unit 12. The control unit 12 calculates the control signal from the input signal of the deflection of the 3D mouse of the input unit 10 using the control curve 11. The control signal is the specification of how fast the end effector 8 should move. The control unit 12 outputs this signal to the robot 2, which moves the end effector 8 at the specified speed by moving the robot arm 4. The input signal is mapped on the x-axis and the end effector speed on the y-axis. The input signal can in particular be the deflection angle from the zero position of the joystick.A linear relationship between the input signal and the end effector velocity is shown as a dashed line for comparison. In this case, the linear relationship is shown as a straight line through the origin with a slope of 1 and means that the end effector velocity increases proportionally with the deflection angle. In particular, the 3D mouse has six degrees of freedom, three translational and three rotational, each as six input signals (x, y, z, rx, ry, rz). A single individual control curve 11 can be stored for each degree of freedom. Or one (translational) control curve 11 can be stored for the translational degrees of freedom and one (rotational) control curve 11 for the rotational degrees of freedom, so that one (translational) control curve 11 is applied uniformly for the translational degrees of freedom and one (rotational) control curve 11 is applied uniformly for the rotational degrees of freedom.Alternatively, a single nonlinear control curve 11 can be stored, which is applied to all six degrees of freedom. In particular, a temporal adjustment can also be made such that, with the deflection of the 3D mouse, starting at time zero t_0, a control curve 11 is gradually changed and increased, so that, viewed over time, with longer deflection, a speed is also continuously increased up to a maximum speed at time t_max.

[0069] Figure 2 shows a control curve 11 according to an embodiment that establishes a quadratic relationship between the input signal (x) and the end effector speed as the control signal f(x). In a range with a small deflection angle A (<50% of maximum deflection), the input signal leads to a small change in the end effector speed. In the range of the small deflection angle A, the control curve 11 lies below the origin line. This means that the change in the input signal leads only to a small or slow movement of the end effector 8. This enables fine control.

[0070] In a range with a larger deflection angle B (>50% of maximum deflection), the input signal leads to a higher end effector speed due to the quadratic relationship between the input signal and the end effector speed. Control curve 11 lies above the dashed line through the origin in range B. Changes in the input signal therefore lead to a large or rapid movement of end effector 8. This allows end effector 8 to be moved quickly to the desired position. This means that coarse control of end effector 8 is achieved.

[0071] Fig. 3 shows a further control curve 11 for converting the input signal into the control signal according to a further embodiment. The control curve 11 is divided into three different regions. In a first region with a small deflection angle A, the control curve 11 is essentially quadratic. This means that a small input signal leads to a small control signal and the end effector speed is correspondingly low. In the first region A, the control curve 11 lies below the dashed line through the origin. In a region with a larger deflection angle B, the control curve 11 can, for example, be a root function. This causes the control signal to approach a maximum. The maximum lies above the line through the origin in region B. Region B is essentially a region with a large deflection angle and a correspondingly large control signal. In a medium region C, the control curve 11 can, for example, be linear.In this way, a control curve 11 can be realized that is optimally adapted to the application and is adjusted differently in different sections.

[0072] Fig. 4 shows a flowchart of a control method according to a preferred embodiment.

[0073] In step S1, the input unit 10 detects the user's input signal. The input signal is, in particular, the extension angle from a zero position of the input unit 10 in the form of a joystick.

[0074] In step S2, the detected input signal is input or read into the control unit 12.

[0075] In step S3, the control unit 12 calculates the control signal of a speed specification of the end effector 8 in the specified direction from the input signal by means of the (stored) non-linear control curve 11.

[0076] In step S4, the control unit 12 controls the robot 2 with the movable robot arm 4 based on the calculated control signal and moves the end effector 8 according to the speed specification.

[0077] 1 robot system

[0078] 2 robots

[0079] 4 Robot arm

[0080] 6 Robot base

[0081] 8 End effector

[0082] 10 Input unit

[0083] 11 Control curve

[0084] 12 Control unit

[0085] 14 Display

[0086] 16 Output unit

[0087] 18 Camera

[0088] A Area with low speed setting

[0089] B middle area

[0090] C Area with high speed specification

Claims

Claims 1. A medical robot system (1) for adapted control of an end effector (8), in particular for controlling a visualization unit as an end effector (8), during an intervention on a patient, comprising: a robot (2) with a movable robot arm (4) and the end effector (8), which is connected to the robot arm (4) and movable by the robot arm (4); an input unit (10), in particular a force-sensitive input unit, in particular a joystick with a deflection angle from a zero position as an input signal, for manual input of an input signal to the robot (2) by a user; and a control unit (12) adapted to control the movement of the robot arm (4), and thus in particular the position and / or orientation of the end effector (8), based on the input signal;characterized in that the control unit (12) is adapted to convert the input signal by means of a non-linear control curve (11) into a control signal of a speed specification of the end effector (8) in a predetermined direction in order to control the movement of the end effector (8); 2. Medical robot system (1) according to claim 1, characterized in that the non-linear control curve is a function dependent on the input signal multiplied by the input signal itself, which is stored in particular in a memory unit.

3. Medical robot system (1) according to claim 1 or 2, characterized in that in a graph with the input signal as abscissa and the control signal as ordinate, the control curve in a range of less than 20%, preferably less than 30% and particularly preferably less than 50% of a maximum input of the input unit, in particular a maximum deflection, below a origin line with gradient 1, so that the speed setting is smaller with a lower input signal than with a linear control.

4. Medical robot system (1) according to one of claims 1 to 3, characterized in that in a graph with the input signal as abscissa and the control signal as ordinate, the control curve in a range above 90% of a maximum input of the input unit, in particular a maximum deflection, lies above an origin line with a gradient of 1, so that the speed specification is greater with a larger input signal than with a linear control.

5. Medical robot system (1) according to one of claims 1 to 4, characterized in that a derivative of the control curve is linear or quadratic or at least partially linear.

6. Medical robot system (1) according to one of claims 1 to 5, characterized in that two different input signals can be detected via the input unit (10), in particular the input unit (10) is designed as a joystick which can be deflected in two directions, each with a deflection angle from a zero position as the input signal, wherein the control unit (12) is adapted to convert the first input signal by means of a first non-linear control curve into a control signal of a speed specification of the end effector (8) in a first predetermined direction and to convert the second input signal by means of a second control curve, which differs from the first control curve, into a control signal of a speed specification of the end effector (8) in a second predetermined direction.

7. Medical robot system (1) according to one of claims 1 to 6, characterized in that the input unit (10), in particular the joystick, is arranged on the end effector (8), in particular is rigidly fastened, and the direction of the deflection or the application of force specifies the predetermined direction of the movement of the end effector (8).

8. Medical robot system (1) according to one of claims 1 to 7, characterized in that the control unit (12) is adapted to switch at least temporarily between an amplification mode in which the non-linear control curve is applied to the input signal and a normal mode in which the input signal is proportionally converted into a control signal.

9. Medical robot system (1) according to one of claims 1 to 8, characterized in that the control unit (12) is adapted to convert the input signal in a translation mode by means of the non-linear control curve only to a translational speed specification in the predetermined direction in order to control a translational movement of the end effector, or to convert the input signal in a rotation mode by means of the non-linear control curve only to a rotational speed specification in the predetermined rotational direction in order to control a rotational movement of the end effector.

10. Medical robot system (1) according to one of claims 1 to 3, characterized in that the control unit (12) is adapted to vary or change the control curve during a movement of the end effector (8) in order to adapt the control in real time during a movement 11. Medical robot system (1) according to one of claims 1 to 10, characterized in that the end effector (8) is connected to a distal end of the movable robot arm (2) and is in particular a visualization unit, particularly preferably a surgical microscope, a gripper arm and / or a trocar.

12. Medical robot system (1) according to one of claims 1 to 11, characterized in that the input unit (10) is a 3D mouse, a force and / or a torque sensor and / or an optical input system.

13. Control method for a medical robot system (1) for an adapted control of an end effector (8), in particular for a control of a visualization unit, during an intervention on a patient, characterized by the following steps: Detecting an input signal of a user by an input unit (10), in particular a deflection angle from a zero position of the input unit (10); Reading the detected input signal into a control unit (12); Calculating a control signal of a speed specification of the end effector (8) in a predetermined direction on the basis of the input signal by the control unit (12) by means of a non-linear control curve, which is preferably stored in a memory unit; Controlling a robot (2) of the robot system (1) with a movable robot arm (4) and the end effector (8) which is connected to the robot arm (4) and can be moved by the robot arm (4), by the control unit (12) on the basis of the calculated control signal.

14. A computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to carry out the steps of the control method according to claim 13.

15. A computer program comprising instructions which, when executed by a computer, cause the computer to carry out the steps of the control method according to claim 13.

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