Method for operating a robotic manipulator in the case of an increase in the mass of the load

Abstract

The present invention relates to a method for operating a robotic manipulator (1), comprising the following steps: - determining (S1) a force screw or a joint torque vector based on the gravitational force and / or inertial force of the mass of the load (5); - determining (S2) a maximum allowable workspace and / or maximum allowable kinematic variables respectively based on the force screw or the joint torque vector, such that the force screw or the joint torque vector within the workspace does not exceed a predetermined measure; and - controlling (S5) the robotic manipulator (1) to perform a predetermined task taking into account the maximum allowable kinematic variables and performing the predetermined task in such a way that when the load (5) at the end effector (3) or optional end effector (3) is within the maximum allowable workspace at the start of task execution, the load (5) at the end effector (3) or optional end effector (3) remains within the maximum allowable workspace.

Description

Technical Field

[0001] The present invention relates to a method for operating a robotic manipulator and a robotic system having a robotic manipulator and a control unit for performing the method, the robotic manipulator having an end effector. Background Art

[0002] The following information does not necessarily belong to any specific prior art, but is generated by expert consideration of the mechanics of robotic manipulators. The additional mass of the load at the end effector of the robotic manipulator generates a moment that acts on the base of the robotic manipulator and typically on the joints of the robotic manipulator. If the mass of the load is very large compared to the mechanical design of the robotic manipulator, the tensile limit or yield point of the material in the limbs or joints of the robotic manipulator, especially in the transmission or torque sensor, may be reached at any time. Therefore, it is obvious to define a maximum allowable mass for the load at the end effector. However, this limits the operation of the robotic manipulator to exactly handling the maximum allowable mass of the load. Therefore, an object of the present invention is to overcome this drawback and also operate a load of a larger mass at the end effector of the robotic manipulator. Summary of the Invention

[0003] The present invention results from the features of the independent claims. Advantageous improvements and designs are the subject matter of the dependent claims.

[0004] A first aspect of the present invention relates to a method for operating a robotic manipulator, having the following steps:

[0005] - determining a force screw or joint torque vector based on the gravity of the mass and / or the force caused by the inertia of the mass of a load arranged at the end effector of the robotic manipulator;

[0006] - determining a maximum allowable workspace and / or maximum allowable kinematic variables of the end effector or optionally the load respectively based on the force screw or joint torque vector, wherein the maximum allowable workspace specifies a range of allowable positions of the end effector or optionally the load, such that the force screw or the joint torque vector within the workspace does not exceed a predetermined measure; and

[0007] - controlling the robotic manipulator by a control unit to perform a predetermined task while taking into account the maximum allowable kinematic variables and performing the predetermined task such that when the end effector or optionally the load at the end effector is located within the maximum allowable workspace at the start of the execution of the task, the end effector or optionally the load at the end effector remains within the maximum allowable workspace.

[0008] Determine the force screw or joint torque vector based on the gravity based on mass and / or the force caused by the inertia of the mass of the load arranged at the end effector of the robotic manipulator. The force screw particularly specifies the force, and further preferably, additionally or alternatively preferably only specifies the torque, particularly with respect to the earth-fixed coordinate system and preferably the Cartesian coordinate system. The mass itself generates gravity in the earth's gravitational field, and this gravity generates torques on the joints of the robotic manipulator and on the base of the robotic manipulator. In the static case, the mass of the load is only responsible for the gravity. In the dynamic case, i.e., when the robotic manipulator is moving, due to the inertia of the mass of the load at the end effector, inertial forces also act. Particularly, in the case of the uniform circular motion of the robotic manipulator, centrifugal forces also act. When the inertial torque generated by the load at the end effector changes, Coriolis forces also act, and when the robotic manipulator accelerates in its path, forces opposing the acceleration generated from the inertia of the mass also act. The joint torque vector is the vector related to the force screw from the joint torques.

[0009] Therefore, in addition to the predictive determination, as long as the mass of the load at the end effector is known, it is very easy to determine the force screw for all static cases. Because then the gravity of the load is also known. And due to the inertia of the mass of the load at the end effector, the determination of the force screw or joint torque vector is particularly carried out predictively based on the planned task or a set of tasks, where, in particular, the trajectory of the load at the end effector and thus also the corresponding path curve and the planned acceleration of the load at the end effector can be derived from the respective task.

[0010] Therefore, the determined force screw or joint torque vector does not necessarily have to actually exist at the robotic manipulator, but can also be a predictively determined hypothetical force screw or joint torque vector that may occur during the corresponding execution of the task or when the load is correspondingly arranged at the end effector of the robotic manipulator.

[0011] The maximum allowable kinematic variables of the end effector or the load at the optional end effector are particularly the speed or acceleration of the end effector or the load at the optional end effector. Whether the end effector or the load at the end effector is considered plays only a secondary role or no role in the concept of the present invention.

[0012] The working space is preferably a spherical space, the center of which is within or in the region of the base of the robotic manipulator, or alternatively preferably a cuboid space. Additionally, an ellipsoid or a part thereof is possible. Other shapes are possible, depending on which calculation method is used and with what precision the working space is determined. Thus, it is also possible to determine the working space only approximately and to provide a pre-defined finite number of cuboids or spheres or other regions with different volumes in order to select the next suitable approximation from this finite number.

[0013] At least when the load at the end effector or optional end effector is within the maximum allowable working space at the start of task execution, the control unit connected to the robotic manipulator determines the predefined task in such a way that the determined maximum allowable working space and maximum allowable kinematic variables are observed. For this purpose, the task can be restricted outside these maximum allowable geometric and kinematic ranges, modified, or at least an indication can be given to the user on how the task should be modified so as not to exceed these geometric or kinematic ranges.

[0014] If the load at the end effector or optional end effector is not within the maximum allowable working space at the start of task execution, then preferably the task is not executed at all, or alternatively preferably, in response to a signal from the control unit, the robotic manipulator and especially the load at the end effector or optional end effector move back into the geometrically maximum allowable working space at a speed and / or acceleration within the corresponding allowable kinematic variables, and especially then the task is started by the control unit.

[0015] The predefined measure is especially the limit value for the torque exerted on the base of the robotic manipulator, i.e. especially the base, due to the weight of the load, where the predefined measure can be specified as the radius from the vertical axis passing through the base of the robotic manipulator to the load multiplied by the mass of the load. In particular, if the mass of the load is constant and known, the measure can also simply consist of the limit value compared to this radius.

[0016] The advantageous effect of the present invention is that a robotic manipulator whose general operation is restricted to the maximum allowable mass of the load at the end effector can also be operated at the end effector with a greater mass.

[0017] According to an advantageous embodiment, the maximum allowable working space and / or the maximum allowable kinematic variables of the end effector or, optionally, the load at the end effector are determined respectively based on the mass distribution of the robotic manipulator and / or the center of gravity of the robotic manipulator and / or the mass of the end effector of the robotic manipulator and / or the center of gravity of the end effector. In order to determine the total torque acting on the base of the robotic manipulator or even on a limb or even on a joint, the total mass distribution of the robotic manipulator together with the end effector and the mass of the load is necessary. Whether it is to determine a clear mass distribution or to combine the mass distributions in the respective centers of gravity of the elements of the robotic manipulator or in the overall center of gravity of the robotic manipulator and to consider them with the corresponding inertia tensor only plays a secondary role. Advantageously, this embodiment enables the maximum allowable working space and / or the maximum allowable kinematic variables to be determined depending on the maximum predetermined torque on the respective elements (base, transmission, joint, torque sensor, link, …) of the robotic manipulator.

[0018] According to another advantageous embodiment, the gravity of the load is determined by static or dynamic system identification. In static system identification, the robotic manipulator is held in a stationary position and preferably the corresponding joint torques are detected by torque sensors, especially in the joints of the robotic manipulator, and from this the gravity of the load is determined and, in turn, the mass of the load is determined. Other force and / or torque sensors known in the prior art can be used to detect the gravity of the load and thus determine the mass of the load. In dynamic system identification, a sinusoidal signal, especially with a frequency increasing over time, is specified as the input signal for at least one actuator of the robotic manipulator, and the response of the robotic manipulator or even the control variable generated by the regulator of the robotic manipulator, especially the current intensity of an electric actuator, is detected. When the kinematic response of the robotic manipulator is detected, the spectra of the input signal and the output signal are generated, and these spectra provide a frequency response in the case of corresponding signal processing and spectral division of each other, from which the mass of the load at the end effector can be read out, or the mass can be approximated as a mass model by an optimization method, namely, by approximating the parameters of the mass model, especially the parameters of the robotic manipulator including the mass of the load, so that the error between the mass model and the frequency response is minimized. Advantageously, by this embodiment, the mass of the load does not have to be predetermined and informed to the control unit of the robotic manipulator, but the control unit of the robotic manipulator can determine the exact mass of the load at the end effector of the robotic manipulator with the aid of the corresponding sensors at the robotic manipulator itself.

[0019] According to another advantageous embodiment, the robot manipulator is controlled to perform the predetermined task by specifying virtual walls at the boundaries of the maximum allowable working space, taking into account the maximum allowable working space, wherein, in order to generate the virtual walls, the robot manipulator is controlled such that when the robot manipulator is manually guided, the robot manipulator exerts a force directed away from the virtual walls on itself. The force directed away from the virtual walls can increase gradually, so that the user feels a smooth transition in the direction of the corresponding virtual wall as the robot manipulator overcomes the increasing resistance to guiding the robot manipulator onto the virtual wall when manually guiding the robot manipulator. Alternatively, preferably, the virtual walls are hard boundaries, so that a sudden reaction force of the robot manipulator occurs on the virtual walls as if the user were actually moving against a physical wall when manually guiding the robot manipulator. Advantageously, this embodiment allows for intuitive support of the user's manual guidance, so that the user intuitively receives feedback on which geometric limits of the working space have been defined. The virtual walls can be implemented not only in a Cartesian fixed coordinate system, but also as artificial stops at the corresponding joints, thereby artificially limiting the angular range of the corresponding joints in the latter case.

[0020] According to another advantageous embodiment, controlling the robot manipulator to perform the specified task taking into account the maximum allowable working space and / or the maximum allowable kinematic variables includes controlling the brakes of the robot manipulator, wherein the brakes of the robot manipulator start in a closed state and are only disengaged when the end effector or optionally the load at the end effector is within the allowable working space at the start of the task. If, for example, a user has placed a load with a nominal non-allowable mass at the end effector, the brakes can remain closed when the mass of the load would, due to its gravity alone, cause non-allowable damage to the drive mechanism of the robot manipulator, in order to protect, in particular, the drive mechanism at the joints of the robot manipulator. Advantageously, this increases the service life of the robot manipulator, in particular the service life of the drive mechanism of the robot manipulator, or advantageously prevents premature shortening of the service life of the robot manipulator.

[0021] According to another advantageous embodiment, the determination of the maximum allowable workspace and / or the maximum allowable kinematic variables based on the trajectory predefined by the predefined task for the robotic manipulator and based on the inertia tensor generated by the trajectory for the robotic manipulator and / or the end effector and / or the load is carried out by determining the time-dependent acceleration of the robotic manipulator and / or the end effector and / or the load from the predefined trajectory, and by determining the time-dependent inertia tensor of the robotic manipulator and / or the end effector and / or the load from the time-dependent pose of the robotic manipulator dependent on the predefined trajectory. The trajectory of the robotic manipulator particularly has information on the path curve and further preferably additionally has time information assigned to the path curve, so that in the concept of the trajectory of the robotic manipulator, preferably not only the geometric path of the end effector or the load is included, but also the corresponding speeds and / or accelerations occurring when following the path curve. Thus, there is sufficient kinematic information to determine the dynamic torques caused by the inertia of the mass of the load, and when operating the robotic manipulator and especially when performing the predefined output, not only the gravity of the mass of the load is considered, but also the dynamic forces causing torques on the limbs, joints and base of the robotic manipulator are considered.

[0022] According to another advantageous embodiment, the method further has the following steps:

[0023] - checking whether the predefined task leaves the maximum allowable workspace of the end effector or optionally the load and / or whether the maximum allowable kinematic variables of the end effector or optionally the load are exceeded; and

[0024] - outputting an indication to the user at the output unit on how the task can be changed so that the maximum allowable workspace of the end effector or optionally the load is not left and / or the maximum allowable kinematic variables of the end effector or optionally the load are not exceeded when performing the task.

[0025] The output unit is preferably a screen on which it is preferably shown to the user by arrows how the task can be changed so that the maximum allowable workspace and the maximum allowable kinematic variables are not exceeded when performing the task. Thus, advantageously, the user receives intuitive feedback on how the task should be changed, so that in particular the service life of the robotic manipulator is not unnecessarily reduced when performing a task with a load exceeding the nominal allowable mass, or the safe operation of the robotic manipulator is further ensured.

[0026] According to another advantageous embodiment, the maximum allowable workspace and / or the maximum allowable kinematic variables are determined by a non-linear optimization search algorithm. If an analytical solution for determining the maximum allowable workspace and / or the maximum allowable kinematic variables is possible, the non-linear optimization method is advantageously suitable for finding the corresponding limits. The non-linear optimization method is in particular a systematic search algorithm, such as gradient-based methods, quadratic optimization methods, genetic and evolutionary algorithms, and the hybrid forms mentioned above. The limits for the non-linear optimization are then given in particular by observing a predetermined measure and observing the allowable kinematic variables.

[0027] According to another advantageous embodiment, the starting point of the search algorithm is the angular position of the second joint counted from the distal link of the robotic manipulator at which the moment of gravity on the second joint has the greatest influence. In particular, a person skilled in the art can immediately determine this angular position by knowing the mechanical conditions at the robotic manipulator. In particular, with the third joint counted from the distal link of the robotic manipulator held, the second joint is then preferably perturbed, preferably within a cone having a vertical axis of rotation, in order to achieve a reduction in the load on the second joint.

[0028] Another aspect of the invention relates to a robotic system having a robotic manipulator and a control unit, the robotic manipulator having an end effector, wherein the control unit is configured to determine a force screw or a joint torque vector based on the gravity of the mass and / or the force caused by the inertia of the mass of a load arranged at the end effector of the robotic manipulator, and the control unit is configured to determine the maximum allowable workspace and / or the maximum allowable kinematic variables of the end effector or optionally the load respectively based on the force screw or the joint torque vector, wherein the maximum allowable workspace specifies the range of allowable positions of the end effector or optionally the load, such that the force screw or the joint torque vector within the workspace does not exceed a predetermined measure, and the control unit is configured to control the robotic manipulator by the control unit to perform a predetermined task taking into account the maximum allowable kinematic variables and to perform the predetermined task in such a way that when the end effector or optionally the load at the end effector is located within the maximum allowable workspace at the start of the execution of the task, the end effector or optionally the load at the end effector remains within the maximum allowable workspace.

[0029] The advantages and preferred refinements of the proposed robotic system result from a similar and meaningful transfer of the above-described embodiments made in connection with the proposed method.

[0030] Further advantages, features, and details result from the following description, in which at least one embodiment is described in detail, with reference to the drawings as necessary. Identical, similar, and / or functionally identical parts are provided with the same reference signs. Description of the Drawings

[0031] Figure 1 A method according to an embodiment of the present invention is shown; and

[0032] Figure 2 A robot system according to another embodiment of the present invention is shown.

[0033] The illustrations in the drawings are schematic and not drawn to scale. Detailed Description of the Embodiment

[0034] Figure 1 A method for operating a robot manipulator 1 is shown. Figure 1 The method of Figure 2 is executed on the robot system 100 described in Figure 2 Therefore, the explanation of

[0035] - Determine the S1 force screw or joint torque vector based on the gravity of the mass and / or the force caused by the inertia of the mass of the load 5 arranged at the end effector 3 of the robot manipulator 1. The gravity of the mass of the load 5 is determined by static system identification. This means that after the user arranges the load 5 at the end effector 3, the torque sensors arranged in the joints of the robot manipulator 1 detect the torque, and the mass of the load 5 is obtained from the known mass distribution of the robot manipulator 1 and the end effector 3 through the current joint angles of the robot manipulator 1. The force caused by the inertia of the mass of the load 5 arranged at the end effector 3 of the robot manipulator 1 is predictively determined by analyzing a predetermined task and determining the trajectory of the end effector 3 or the load 5.

[0036] - Determine the maximum allowable workspace and / or maximum allowable kinematic variables of the end effector 3 of S2 respectively based on the force screw or joint torque vector, wherein the maximum allowable workspace specifies the range of allowable positions of the end effector 3, so that the force screw or joint torque vector within the workspace does not exceed a predetermined limit value. Determine the maximum allowable workspace and / or maximum allowable kinematic variables of the end effector 3 respectively based on the mass distribution of the robotic manipulator 1 and the mass distribution of the end effector 3 and based on the mass and inertia tensor of the load 5. Due to the fully known mass distribution of all components of the robotic manipulator 1 including the load 5, the torque on the base of the robotic manipulator 1 is known through the integration of all mass elements over the radius. Now generate the maximum allowable workspace, maximum allowable speed and acceleration of the end effector 3 by a gradient-based search method. In the gradient-based method, additional search points in the objective function are determined around a starting point at a certain distance to comply with a predetermined metric, i.e., the limit value in the torque on the base of the robotic manipulator 1. Determine the gradient from these search points and multiply the gradient by a predetermined length to obtain the next step. This method is iteratively repeated until the algorithm has converged and the magnitude of the gradient has fallen below a certain threshold. A cylindrical region is obtained from this calculation to limit the maximum allowable workspace. In addition, determine the maximum allowable speed and acceleration of the end effector 3 based on the trajectory predefined by a predetermined task of the robotic manipulator 1 and based on the inertia tensor generated by the robotic manipulator 1, the end effector 3 and the load 5 along this trajectory. This is done considering the already determined maximum allowable workspace. The predefined trajectory provides the time-dependent acceleration of the robotic manipulator 1, the end effector 3 and the load 5. Then, all inertial torques and accelerations are known from the time-dependent pose of the robotic manipulator 1 depending on the predefined specification and the time-dependent inertia tensor of the robotic manipulator 1, the end effector 3 and the load.

[0037] - Check whether the S3 predetermined task leaves the maximum allowable workspace of the end effector 3 and whether it exceeds the maximum allowable kinematic variables of the end effector 3;

[0038] - Output a S4 visual indication to the user in the form of an arrow on the screen 11 of the user computer connected to the control unit 7, indicating how the task can be changed by the user so as not to leave the maximum allowable workspace of the end effector 3 and / or not to exceed the maximum allowable kinematic variables of the end effector 3 when performing the task;

[0039] - The robot manipulator 1 is controlled by the control unit 7 to perform the predetermined task S5 while considering the maximum allowable kinematic variables, and the predetermined task is performed such that when the end effector 3 or the load 5 at the optional end effector 3 is within the maximum allowable workspace at the start of task execution, the load 5 at the end effector 3 or the optional end effector 3 remains within the maximum allowable workspace. The determined cylindrical workspace serves as the basis for generating a virtual wall on the outer lateral surface of the cylinder. Here, the robot manipulator 1 is controlled to perform the predetermined task such that when the robot manipulator 1 is manually guided, the robot manipulator 1 exerts a force directed away from the virtual wall on the robot manipulator 1 to generate the virtual wall. If the load 5 is outside the outer lateral surface of the cylindrical workspace at the start of task execution, the brakes 9 of the robot manipulator are not released at all. For this purpose, an indication is displayed to the user on the screen 11 indicating that the load 5 is outside the allowable workspace.

[0040] Figure 2 The robot system 100 is shown. The robot system 100 is in particular implemented to perform Figure 1 the method and has a robot manipulator 1 and a control unit 7, the robot manipulator 1 having an end effector 3, wherein the control unit 7 is implemented to determine a force screw or a joint torque vector based on the gravity of the mass and / or the force caused by the inertia of the mass of the load 5 arranged at the end effector 3 of the robot manipulator 1, and the control unit 7 is implemented to determine the maximum allowable workspace and / or the maximum allowable kinematic variables of the end effector 3 or the optional load 5 respectively based on the force screw or the joint torque vector, wherein the maximum allowable workspace specifies the range of the allowable position of the load 5 at the end effector 3 or the end effector 3 such that the force screw or the joint torque vector within the workspace does not exceed a predetermined measure, and the control unit 7 is implemented to control the robot manipulator to perform a predetermined task by the control unit 7 while considering the maximum allowable kinematic variables and to perform the predetermined task such that when the load 5 at the end effector 3 or the optional end effector 3 is within the maximum allowable workspace at the start of task execution, the load 5 at the end effector 3 or the optional end effector 3 remains within the maximum allowable workspace.

[0041] Although the present invention has been illustrated and described in more detail by preferred embodiments, the present invention is not limited to the disclosed embodiments, and those skilled in the art can derive other variations therefrom without departing from the scope of protection of the present invention. Therefore, it is obvious that there are various possible variations. It is also obvious that the embodiments cited by way of example actually only represent examples and should not be understood in any way as, for example, a limitation on the scope of protection of the present invention, possible applications or configurations. On the contrary, the foregoing description and the description of the drawings enable those skilled in the art to specifically implement the exemplary embodiments, wherein those skilled in the art, in the case of understanding the disclosed inventive concept, can make various changes, for example, to the functions or arrangements of the individual elements mentioned in the exemplary embodiments, without departing from the scope of protection defined by the claims and their legal equivalents, such as further explanations in the specification.

[0042] Description of Reference Numerals:

[0043] 1 Robot Manipulator

[0044] 3 End Effector

[0045] 5 Load

[0046] 7 Control Unit

[0047] 9 Brake

[0048] 11 Output Unit

[0049] 100 Robot System

[0050] S1 Determination

[0051] S2 Determination

[0052] S3 Inspection

[0053] S4 Output

[0054] S5 Control

Claims

1. A method for operating a robotic manipulator (1), comprising the following steps: - Determining (S1) a force screw or joint torque vector based on the gravity of the mass and / or the force caused by the inertia of the mass of a load (5) arranged at the end effector (3) of the robotic manipulator (1); - Determine (S2) the maximum allowable workspace and the maximum allowable kinematic variables of the end effector (3) or optionally the load (5) respectively based on the force screw or the joint torque vector, wherein, The maximum allowable workspace specifies the range of allowable positions of the end effector (3) or optionally the load (5), such that the force screw or the joint torque vector within the workspace does not exceed a predetermined torque applied to the base of the robotic manipulator. Wherein, the predetermined measure is the limit value of the torque applied to the base of the robotic manipulator (1) by the gravity of the load (5), and the predetermined measure is specified as the radius from the vertical axis passing through the base of the robotic manipulator (1) to the load (5) multiplied by the mass of the load (5), so that the robotic manipulator (5) whose general operation is restricted to the maximum allowable mass at the end effector can also be operated with a greater mass at the end effector (3); and - Controlling (S5) the robotic manipulator (1) by a control unit (7) to perform a predetermined task while considering the maximum allowable kinematic variables and performing the predetermined task such that when the end effector (3) or optionally the load (5) at the end effector (3) is located within the maximum allowable workspace at the start of task execution, the end effector (3) or optionally the load (5) at the end effector (3) remains within the maximum allowable workspace.

2. The method according to claim 1, wherein The maximum allowable workspace and the maximum allowable kinematic variables of the end effector (3) or optionally the load (5) at the end effector (3) are determined respectively based on the mass distribution of the robotic manipulator (1) and / or the center of gravity of the robotic manipulator (1) and / or the mass of the end effector (3) of the robotic manipulator (1) and / or the center of gravity of the end effector (3).

3. The method according to any one of the preceding claims, wherein, The gravity of the mass of the load (5) is determined by static or dynamic system identification.

4. The method according to any one of the preceding claims, wherein, Controlling the robotic manipulator (1) to perform the predetermined task by specifying virtual walls at the boundaries of the maximum allowable workspace while considering the maximum allowable workspace. Wherein, in order to generate the virtual walls, the robotic manipulator (1) is controlled such that when the robotic manipulator (1) is manually guided, the robotic manipulator (1) applies a force pointing away from the virtual wall to the robotic manipulator (1).

5. The method according to any one of the preceding claims, wherein, Controlling the robotic manipulator (1) to perform the specified task while taking into account the maximum allowable workspace and / or the maximum allowable kinematic variables includes controlling the brakes (9) of the robotic manipulator (1), wherein the brakes (9) of the robotic manipulator (1) start from a closed state and are only disengaged when the end effector (3) or optionally the load (5) at the end effector (3) is within the allowable workspace at the start of the task execution.

6. The method according to any one of the preceding claims, wherein, The determination of the maximum allowable workspace and the maximum allowable kinematic variables based on the trajectory predefined by the predefined task of the robotic manipulator (1) and based on the inertia tensor generated by the trajectory of the robotic manipulator (1) and / or the end effector (3) and / or the load (5) is carried out in such a way that the time-dependent acceleration of the robotic manipulator (1) and / or the end effector (3) and / or the load (5) is determined from the predefined trajectory, and in such a way that the time-dependent inertia tensor of the robotic manipulator (1) and / or the end effector (3) and / or the load (5) is determined from the time-dependent pose of the robotic manipulator (1) dependent on the predefined trajectory.

7. The method according to any one of the preceding claims, further comprising the following steps: - Checking (S3) whether the predefined task leaves the maximum allowable workspace of the end effector (3) or optionally the load (5) and / or whether it exceeds the maximum allowable kinematic variables of the end effector (3) or optionally the load (5); and - Outputting (S4) an indication to the user at the output unit (11) indicating how the task can be changed so as not to leave the maximum allowable workspace of the end effector (3) or optionally the load (5) and not to exceed the maximum allowable kinematic variables of the end effector (3) or optionally the load (5) when performing the task.

8. The method according to any one of the preceding claims, wherein, The maximum allowable workspace and the maximum allowable kinematic variables are determined by a search algorithm of nonlinear optimization.

9. The method according to claim 8, wherein, The starting point of the search algorithm is the angular position of the second joint counted from the distal link of the robotic manipulator (1) where the moment of gravity on the second joint has the greatest influence.

10. The method according to claim 1, wherein If the mass of the load (5) is constant and known, the predefined metric also consists only of the limit values compared with the radius.

11. A robot system (100) having a robot manipulator (1) and a control unit (7), the robot manipulator (1) having an end effector (3), wherein, The control unit (7) is implemented to determine a force screw or a joint torque vector based on the gravitational force of the mass and / or the force caused by the inertia of the mass of the load (5) arranged at the end effector (3) of the robotic manipulator (1), and the control unit (7) is implemented to determine the maximum allowable workspace and the maximum allowable kinematic variables of the end effector (3) or optionally the load (5) based on the force screw or the joint torque vector, respectively, wherein the maximum allowable workspace specifies the range of the allowable positions of the end effector (3) or optionally the load (5) such that the force screw or the joint torque vector within the workspace does not exceed a predetermined torque applied to the base of the robotic manipulator, wherein the predetermined measure is the limit value of the torque applied to the base of the robotic manipulator (1) by the gravitational force of the load (5), wherein the predetermined measure is specified as the radius from the vertical axis guided through the base of the robotic manipulator (1) to the load (5) multiplied by the mass of the load (5), such that the robotic manipulator (5) whose general operation is restricted to the maximum allowable mass of the load at the end effector can also be operated with a greater mass at the end effector (3), and the control unit (7) is implemented to control the robotic manipulator (1) by the control unit (7) to perform a predetermined task while taking into account the maximum allowable kinematic variables and to perform the predetermined task in such a way that when the end effector (3) or optionally the load (5) at the end effector (3) is located within the maximum allowable workspace at the start of the execution of the task, the end effector (3) or optionally the load (5) at the end effector (3) remains within the maximum allowable workspace.

12. The robot system (100) according to claim 11, wherein, If the mass of the load (5) is constant and known, the predetermined measure also consists only of the limit value compared with the radius.

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