Repositionable robot system

Abstract

Robot system for treating a patient (22), moving an object or processing a workpiece, with at least one robot arm (10, 12) with one or more manipulator elements (14), wherein the first manipulator element is connected to a robot base (17) and the last manipulator element is connected to an end effector (18) or an optical instrument, a robot controller (32) connected to the at least one robot arm (10, 12) for controlling the movement of the at least one robot arm (10, 12) and a holding element connectable to the robot base for attaching the robot base to the location of the holding element characterized by a sensor (28) connected to the robot base for detecting the position of the robot base relative to the direction of gravity, wherein, when the position of the robot base changes, gravity acts on the manipulator element (14) in a different direction, wherein the sensor is connected to the control device (30) to change the movement of the robot arm (10, 12) depending on the sensor data received, so that the influence of the changing direction of gravity is compensated.

Description

[0001] The invention relates to a portable robot system for treating patients, processing workpieces, or moving objects.

[0002] When controlling a robot system, it is generally advantageous to pre-control the forces and moments acting on the joints due to gravitational effects. This can be achieved using a dynamic model. Holding torques can be determined from the kinematics of the robot system, its current position, and the direction of gravity, ensuring that the robot system is reliably held in position. Simultaneously, the dynamic model ensures that the influence of gravity on the robot segments is correctly accounted for. This is particularly important when high positioning accuracy is required, such as in minimally invasive surgery. For non-repositionable, stationary robot systems, the calibration of the robot base's position relative to gravity is performed only once.Should the robot need to be repositioned again with regard to the position of its base relative to gravity, this calibration must be performed again.

[0003] With robot systems that are manufactured using lightweight construction, it is often possible to mount the robot system in different locations and, in particular, in different positions, so that the robot system can treat a patient, move an object, or process a workpiece, and then the same robot system can be moved to another location or position and can also treat a patient, move an object, or process a workpiece there.

[0004] Some surgical procedures require the operating table, on which the patient is positioned, to be rotated during the operation (intraoperatively). This changes the position of the organs in the body due to gravity, thus clearing the working area and improving the surgeon's view. Particularly in minimally invasive surgery, where operations are performed only through small incisions and using long, thin instruments, repositioning organs is virtually impossible without a rotating operating table. These rotating operating tables are now standard equipment in operating rooms.In robot-assisted minimally invasive surgery, where the robot system is connected to the operating table, it is not possible to swivel the operating table intraoperatively and while the robot is being actively controlled, as compensation is particularly necessary to adapt the robot's movement to the changed position and the resulting change in the direction of gravity.

[0005] When machining workpieces, it may also be advantageous under certain circumstances to carry out the machining in a changed position, especially if the workpiece contains movable and / or deformable parts which can be brought into a position that is advantageous for machining by the changed position and the resulting change in the direction of gravity.

[0006] Typically, changing the position of the robot base requires manual adjustment. This results in longer treatment or processing times and necessitates case-specific intervention by the surgeon or user.

[0007] The object of the invention is therefore to create a robot system which can be used in different positions without calibration.

[0008] According to the invention, this problem is solved by a robot system according to claim 1, and a method according to claim 7.

[0009] The robot system according to the invention for treating a patient, moving an object, or machining a workpiece comprises at least one robot arm. This at least one robot arm has one or more manipulator elements, the individual manipulator elements being connected to each other by hinges and / or pivot joints. Furthermore, the first manipulator element is also connected to a robot base via a roller and / or pivot joint. If the robot arm has only one manipulator element, the first manipulator element is simultaneously the last manipulator element, which is also connected to an end effector. If more than one manipulator element is provided, the last manipulator element is connected to an end effector or an optical instrument.

[0010] Specifically, it is a robot with a base, an end effector mount, and a joint configuration connecting the base and the end effector mount, whereby the joint configuration allows movement of the end effector mount in at least 5 degrees of freedom. This joint configuration also includes parallel kinematics or mechanisms.

[0011] The end effector can be a gripper, a tool, a surgical instrument, a minimally invasive surgical instrument, or the like. The end effector is preferably permanently, but more preferably interchangeably, connected to the last manipulator element of the robot arm via a coupling. Alternatively or additionally, an optical instrument can be connected to the last manipulator element, such as a camera, an endoscope, a fiber-coupled viewing device, a laser, a laser pointer, or the like. The optical instrument is preferably permanently, but more preferably interchangeably, connected to the last manipulator element of the robot arm via a coupling.

[0012] The robot system according to the invention comprises, in particular, more than one robot arm, each of which also has one or more manipulator elements. If more than one robot arm is provided, the first manipulator elements of each robot arm are preferably connected to a common robot base. Thus, even when more than one robot arm is provided, the robot system preferably has only one robot base. In particular, the same, and preferably different, tools and / or optical instruments are connected to the last manipulator element of each individual robot arm. This connection is preferably fixed, but is preferably made via a coupling, so that the individual tools and / or optical instruments are interchangeable.

[0013] According to the invention, a control device is connected to the at least one robot arm for controlling the movement of the at least one robot arm. If more than one robot arm is provided, all robot arms are in particular connected to a common control device.

[0014] According to the invention, the robot base can be connected to a retaining element to secure the robot system at the location of the retaining element. The retaining element can be screws with which the robot base is bolted to the base. Alternatively, the retaining element can be a simple wall or ceiling element to which the robot base is clamped. The retaining element can also have a groove or tongue into which a corresponding tongue or groove of the robot base can be inserted. The connection between the robot base and the retaining element is preferably designed to be detachable and is ideally created by screwing, clamping, hooking, magnetically, or by positive locking. This allows the robot system to be detached from one retaining element and connected to another. The orientation relative to the direction of gravity acting on the retaining elements can differ.

[0015] According to the invention, a sensor is connected to the robot base for position detection of the robot base. The sensor is in particular an accelerometer or, in integrated form, an inertial measurement unit.

[0016] According to the invention, the sensor for detecting the position of the robot base is also connected to the control device for acquiring and evaluating the sensor data. When a change in the position of the robot base is detected, the control device adjusts the movement of the robot arm based on the acquired sensor data. This applies in particular to the torques applied to the individual manipulator elements. The detected position of the robot base allows for recalibration based on the dynamic model, since the direction of gravity is detected by the sensor and the kinematics do not change due to a change in the position of the robot base. Therefore, for recalibration, the robot arm only needs to move to a known position to obtain all the necessary information for calibration based on the dynamic model.In particular, by measuring the position of the robot base, the holding torques required to keep the robot arm in a stable position can be determined. However, the torques required for precise movement of the robot arm also change depending on the position of the robot base. Calibration provides knowledge of these required torques, thus enabling precise movement.

[0017] In particular, the sensor is integrated into the robot base. Preferably, the control device is also integrated into the robot base.

[0018] In a preferred embodiment, the holding element is attached to a tripod, which is particularly capable of rolling and swiveling. This allows the robot base to be attached to the tripod, thus creating a mobile, lightweight robot system.

[0019] In an alternative embodiment, the mounting element is connected to a wall or ceiling, so that the robot base can be attached to the wall or ceiling, particularly in a detachable manner. The wall or ceiling in question is, in particular, a wall or ceiling of an operating room or a factory hall.

[0020] In particular, the holding element is connected to a position-adjustable mounting device. Thus, when the position of the mounting device changes, the position of the robot base also changes. Specifically, when the position of the robot base changes, gravity acts on the individual manipulator elements in a different direction, depending on the position of the robot base. This results in varying forces being required to move the individual manipulator elements, depending on the position of the robot base. For particularly precise movements, such as those required in minimally invasive surgery, these gravitational influences caused by the position change of the robot base must be corrected by the control device. This is achieved by detecting the position of the robot base and, since the robot base is connected to the mounting device, simultaneously detecting the position of the mounting device.The detected position is evaluated by the control device and the movement of the at least one robot arm or the force on the individual manipulator elements is corrected so that the influence of the changed direction of gravity is compensated.

[0021] In particular, the position-adjustable holding device is a position-adjustable workpiece holder. The workpiece is held and supported on the workpiece holder. The workpiece holder is preferably tiltable or pivotable about at least one horizontal axis, and particularly preferably tiltable and pivotable about more than one horizontal axis.

[0022] Alternatively, the position-adjustable receiving device is, in particular, a position-adjustable operating table. The patient is held and positioned on the operating table. The operating table is preferably tiltable or pivotable about at least one horizontal axis, and particularly preferably tiltable and pivotable about more than one horizontal axis.

[0023] When connecting the robot base to the gripping device, it is particularly intended that an emergency stop be initiated if a change in the gripping device's position is detected, or that the at least one robot arm be actively repositioned according to the detected change in position. In particular, it is also possible that, upon detection of a change in position, the robot arm is moved to a rest position, preferably along a predetermined path of motion, this path of motion being determined particularly preferably based on the detected position of the gripping device. In particular, it is possible that the control device corrects the movement of the robot arm to compensate for gravitational influences on the individual manipulator elements of the robot arm.

[0024] The invention further relates to a method for controlling a robot arm depending on the position of the robot base relative to the direction of gravity, comprising the steps of first detecting the position of the robot base by a sensor, then evaluating the position by a control device connected to the sensor, and subsequently changing the robot's movement via a robot controller connected to the control device. In particular, the sensor detects the change in the position of the robot base, i.e., a relative change in position, and / or the absolute position of the robot base in relation to the direction of gravity.

[0025] In particular, the procedure has been further developed in accordance with the features described above using the robot system as an example.

[0026] The invention will now be explained in more detail with reference to preferred embodiments and the accompanying drawings.

[0027] They show: Fig. 1 a robotic system for treating a patient in which the robot base is connected to the receiving device (in top view) and Fig. 2 a robot system in which the robot base is attached to a ceiling (in side view).

[0028] The robot system according to the invention exhibits, as in Fig. Figure 1 shows two robot arms 10 and 12, each of which has two manipulator elements 14 connected to each other via joints 16. End effectors 18 are provided on the last manipulator element 14 of each robot arm 10 and 12. The first manipulator element 14 of each arm is connected to a robot base 17. The robot system also includes a receiving device, which is designed in particular as an operating table 20, and to which the robot base is connected via a holding element (not shown). A patient 22 is positioned and held on the operating table 20. The operating table 20 is pivotable about at least two pivot axes 24 and 26, where axes 24 and 26 are horizontal axes. The position of the patient 22 can be changed by pivoting the operating table 20 about the horizontal axes 24 and 26.

[0029] A position sensor 28 is connected to the robot base 17, and in particular, the position sensor 28 is integrated into the robot base 17. The position sensor 28 is connected to a control device 30. The control device 30 acquires and evaluates the sensor data from the position sensor 28. The control device 30 also controls the movement of the two robot arms 10 and 12. Depending on the acquired sensor data from the position sensor 28, the control device 30 modifies the movement of the two robot arms 10 and 12. If the position of the patient 22 is changed by a pivot about, for example, the axis 24, which simultaneously changes the position of the robot base, this change in position is detected by the position sensor 28. As a result of the evaluation, the control device 30 can initiate an emergency stop of the two robot arms 10 and 12 via the robot controller 32.Alternatively, the movement of the two robot arms 10, 12 can be interrupted only during the pivoting process of the operating table 20 about the axis 24. In particular, the control device 30 takes into account the influence of gravity on the movement of the two robot arms 10, 12, so that the gravitational effects are precisely compensated. This leads to an increase in the accuracy of the movement of the two robot arms 10, 12.

[0030] Another embodiment shown in Fig. 2, the robot system has only one robot arm 34. The robot arm 34 has two manipulator elements 14, which are connected to each other via a joint 16. The first manipulator element 14 is connected to the robot base 17. In the Fig. In the embodiment shown in Figure 2, the robot base 17 is connected to a wall 36, and in particular to the ceiling of the operating room, via a first mounting element 35. An end effector 18, which is designed in particular as a surgical instrument, is connected to the last manipulator element of the robot arm 34. The movement of the robot arm 34 is controlled by a robot controller 32.

[0031] A position sensor 28 is connected to the robot base 17. The position sensor 28 detects changes in the position of the robot base 17. The position sensor 28 is connected to a control device 30, which evaluates the acquired sensor data. The control device 30 is also connected to the robot arm 34.

[0032] Furthermore, the robot system in the embodiment shown in Fig. 2, a receiving facility which is designed as operating table 20.

[0033] Furthermore, a second holding element 38 is arranged on the operating table 20. The robot base 17 is detachably connected to the first holding element 35. The robot base 17 of the robot arm 34 can thus be detached from the first holding element 35 and then connected to the second holding element 38. This changes the position of the robot base 17 relative to the direction of gravity. This change in the position of the robot base 17 is detected by the position sensor 28. Depending on the changed position, the control device 30 is automatically recalibrated without requiring manual calibration. Thus, the changes in the holding torque for the individual manipulator elements 14 caused by the changed position, as well as the torques / forces required for precise movement, can be taken into account. In this way, the control device 30 effectively compensates for gravitational influences on the movement of the robot arm 34.

Claims

[1] Robot system for treating a patient (22), moving an object or processing a workpiece, with at least one robot arm (10, 12) with one or more manipulator elements (14), wherein the first manipulator element is connected to a robot base (17) and the last manipulator element is connected to an end effector (18) or an optical instrument, a robot controller (32) connected to the at least one robot arm (10, 12) for controlling the movement of the at least one robot arm (10, 12) and a holding element connectable to the robot base for attaching the robot base to the location of the holding element characterized by a sensor (28) connected to the robot base for detecting the position of the robot base relative to the direction of gravity, wherein, when the position of the robot base changes, gravity acts on the manipulator element (14) in a different direction, wherein the sensor is connected to the control device (30) to change the movement of the robot arm (10, 12) depending on the sensor data received, so that the influence of the changing direction of gravity is compensated. [2] Robot system according to claim 1 characterized by that the robot base is detachably connected to the holding element. [3] Robot system according to claim 1 or 2 characterized by that the holding element is provided on a tripod, which is particularly movable. [4] Robot system according to one of claims 1-3 characterized by that the mounting element is intended to be attached to a wall or ceiling. [5] Robot system according to one of claims 1-4 characterized by , that the holding element is connected to a position-changing receiving device, in particular a position-changing operating table (20). [6] Method for controlling a robot system (10, 12) depending on the position of the robot base, at which The position of the robot base relative to the direction of gravity is detected by a sensor (28), whereby when the position of the robot base changes, gravity acts on the manipulator element (14) in a different direction. the position is evaluated by a control device (30) connected to the sensor (28) and via a robot control (32) connected to the control device (30) the movement of the robot arm (10, 12) is changed so that the influence of the changed direction of gravity is compensated.

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