Method for configuring at least a safety parameter for a safety zone for a robot device

Abstract

The present invention relates to a method (100) for configuring at least a safety parameter (62) for a safety zone (60) for a robot device (70), comprising: - Defining (104) at least a location (10) of a potential contact hazard for the robot device (70); - Determining (106) a spatial zone (20) around the defined location (10) by using at least partly a real-time guided-movement input information (22) provided by a human instructor (80), wherein guided-movement information (22) is generated in that the human instructor (80) moves at least a component (72) of the robot device (70) from a first position (24) to a second target position (26) to define the spatial zone (20); - Providing (108) a contact configuration information (30) for a defined contact situation, that determines at least an exposed body region (32) to estimate a potential contact area (34) within the determined spatial zone (20 ); - Determining (110) at least one safety parameter (62) for configuring the safety zone (60) for the robot device (70 ) on basis of the determined spatial zone (20) and the contact configuration information (30) for the defined contact situation.

Description

[0001] Method for configuring at least a safety parameter for a safety zone for a robot device

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a method for configuring at least a safety parameter for a safety zone for a robot device.

[0004] BACKGROUND OF THE INVENTION

[0005] A growing area of robot applications in industrial manufacturing are so-called collaborative robot applications. The main characteristic distinguishing these from conventional, non-collaborative robot applications is that the working space of the robot system is not closed off by physical or sensory perimeter guarding. It is possible for the human operator approach the robot system to engage in various forms of interaction as called for by the manufacturing task at hand.

[0006] The human operator, however, must be protected from the hazards associated with contact between the moving robot and his body. This can be achieved, for example, by measuring the distance between the operator and robot with according adjustment of the robot speed such that the robot will always come to rest before the operator is able to reach it physically.

[0007] Another form of reducing the risk associated with physical contact between the robot system and the human operator is to ensure that such contact events remain harmless.

[0008] This method of risk reduction is referred to as power and force limiting (PFL). The aim of a protective method is generally to control, for example, the speed and the contact force of the robot with respect to its environment, including the human operator. Currently, each Power and force limiting (PFL) configuration for a robot device is done entirely manually by a user to specify zone coordinates and the configuration parameters for safety function or a safety zone for the robot device.

[0009] For this, a user uses software-based application tools that enable him to provide textual information input or that provide a graphical interface to declare body region exposure and coordinate input information for safety zone limits within a workspace of the robot device. The US2024075620 A1 provides an example for an configuration of a safety zone for robot device.

[0010] A further example describing a safe move application can be found under the following URL: https: / / search.abb.com / library / Download.aspx?DocumentlD=3HAC066559-001.

[0011] However, according to the current approach, the user has to measure or take the coordinates from robot cell design and calculate the parameters based on his knowledge. Thus, very often, unnecessarily conservative values for the safety zone configuration are chosen, often depending on individual experience and knowledge of the human operator configuring the safety parameters for a corresponding safety zone or safety function for the robot system.

[0012] Further, such an approach for a configuration of a safety zone or a safety function parameter for a robot device for several robot application scenarios is often complex and lacks of efficiency and error-prone in particular when an application scenario for the robot system is changing and when dealing with frequent changeovers in applications.

[0013] There is a need to address these issues.

[0014] SUMMARY OF THE INVENTION Therefore, it would be advantageous to provide an improved concept for a configuration of a safety zone parameter or a safety function for a robot device in a simple, efficient and automated manner.

[0015] The object of the present invention is solved by the subject matter of the independent claims, wherein further embodiments are incorporated in the dependent claims.

[0016] In a first aspect of the present invention, there is provided a method for configuring at least a safety parameter for a safety zone for a robot device, comprising the following steps:

[0017] Defining at least a location of a potential contact hazard for the robot device;

[0018] Determining a spatial zone around the defined location by using at least partly a real-time guided-movement input information provided by a human instructor, wherein guided-movement information is generated in that the human instructor moves at least a component of the robot device from a first position to a second target position to define the spatial zone;

[0019] Providing a contact configuration information for a defined contact situation, that determines at least an exposed body region to estimate a potential contact area within the determined spatial zone;

[0020] Determining at least one safety parameter for configuring the safety zone for the robot device on basis of the determined spatial zone and the contact configuration information for the defined contact situation.

[0021] In other words, the present invention allows a more intuitive and effective way of a PFL safety zone or safety function parameter configuration for a robot device. A human operator performs a guided-movement with a component or part of the robot device showing the robot device portions of the robot workspace that are relevant for setting up a safety zone configuration.

[0022] In this way, the human operator is able to accomplish the task of safety configuration of the robot application in an improved manner through haptic input to the robot system. The robot system or robot device can be positioned at locations of contact hazards using the lead-through function, a new approach and as one of the main advantages of the present invention that avoids the input of numerical coordinate data for configuration.

[0023] By specification of contact configuration, e.g. constrained or unconstrained, exposed body region(s) of a human operator or a user, and contact area(s), enough data is provided so as to be able to compute the necessary speed limits, contact force limitations, etc.

[0024] The present invention provides the following advantages:

[0025] By using a haptically intuitive approach of setting up and configuring a safety zone and / or a safety function for a robot device, the process of configuring the appropriate safety functions for PFL risk reduction is improved.

[0026] The lead-through functionality of robots defining the safety configuration could reduce the effort and the requirement of experienced user knowledge.

[0027] It is possible to define the safety configuration without using a special graphical user interface at all, as is the preference of many customers that are first-time robot users. The present invention allows in a efficient and simplified manner a definition of a PFL safety zone configuration without using interfaces requiring numerical input and without the need for the human operator to compute speed limits, force limits, or pressure limits for his application.

[0028] The approach of the present invention to commissioning PFL risk reduction for collaborative applications is in particular relevant for those users of robots for collaborative applications who prefer to limit the effort associated with installing simple robot automation, e.g. first-time users of simple robotic automation. This group of users may not be well-versed in risk assessment and risk reduction for robotic applications and is not well-served by requiring numerical input to configure safety functions. Further, the present invention provides the advantage that the user needs less effort to define a safety parameter configuration for a robot device, as the perceived complexity of such a task is reduced and a much accelerated execution of a configuration task for the robot device for different application scenarios can be enabled.

[0029] According to an example, before the step of defining, a step of determining a contact information about at least one potential contact situation is performed that is used as a first input information for defining the at least one location of the potential contact hazard for the robot device. In this way, configuration of the safety parameters is made more precise and efficient.

[0030] According to an example, the contact information is at least partly provided by the human instructor and I or by an application device. In this way, the contact information can be flexibly provided depending on an application scenario.

[0031] According to an example, for each contact situation the steps of defining and determining are performed. In this way, efficient configuration of the safety parameter is ensured.

[0032] According to an example, for the step of defining the spatial zone, at least one of the following second input information is provided: a dimension parameter of the robot device, information on the at least one exposed body region.

[0033] According to an example, for the step of providing the contact configuration (constrained or unconstrained) information, a robot control system and I or an external sensing device connected to the robot control system is used to provide the contact configuration information. In this way, efficient configuration of the safety parameter is ensured. In a possible practice, it might be most economical to offer the user a choice of the two options on the control device e.g. teach pendant, such that the configuration step is manual with respect to the decision but supported through the GUI.

[0034] According to an example, wherein the step of determining the at least one safety parameter includes calculating a movement parameter for the robot device. In this way, an efficient and precise configuration of the safety parameter depending on a required application scenario is ensured.

[0035] According to an example, wherein the step of defining the spatial zone involves the step of determining an environment information that represents data of an application scenario environment of the robot device within the spatial zone. In this way, an efficient and precise configuration of the safety parameter for the robot device depending on a required application scenario is ensured.

[0036] According to an example, the determined environment information is provided by using means of visualisation for a further human input. In this way, a more simplified way to configure the safety parameter for the robot device depending on a required application scenario is ensured.

[0037] In a second aspect of the present invention, a computer system that is configured to execute the method according any of the previous examples and I or according to the first aspect for configuring a safety zone or a safety function for a robot device.

[0038] In a third aspect of the present invention, a computer comprising a processor configured to perform the method according to the first aspect and I or according to any of the previous examples is provided.

[0039] In a fourth aspect of the present invention, a computer program product comprising instructions which, when the computer program is executed by a processor of a computer, causes the computer to perform the method of the first aspect and I or of any of the previous examples.

[0040] In a fifth aspect of the present invention, a machine-readable data medium and I or download product is provided containing the computer program according to the fifth aspect.

[0041] BRIEF DESCRIPTION OF THE DRAWINGS Exemplary embodiments will be described in the following with reference to the following drawings:

[0042] Fig. 1 illustrates a schematic flow-diagram of a method of the present invention;

[0043] Fig. 2 illustrates a schematic overview of the robot device and robot system according to an embodiment of the present invention;

[0044] Fig. 3 illustrates a schematic example for positioning the robot device by a human operator according to an embodiment of the present invention;

[0045] Fig. 4 illustrates a schematic flow-diagram for generating a safety configuration for a robot device according to an embodiment of the present invention; and

[0046] Fig. 5 illustrates a schematic flow-diagram for generating a safety configuration for a robot device according to an embodiment of the present invention.

[0047] DETAILED DESCRIPTION OF THE DRAWINGS

[0048] Fig. 1 (with reference to Fig. 2 and Fig. 3) illustrates a schematic flow-diagram of a method of the present invention.

[0049] In a first step 104, at least a location or an area 10 of a potential contact hazard for the robot device 70 is defined.

[0050] In a second step 106, a spatial zone 20 around the defined location 10 is defined by using at least partly a real-time guided-movement input information 22 provided by a human instructor 80. The guided-movement information 22 is generated in that the human instructor 80 moves at least a component 72 of the robot device 70 from a first position 24 to a second target position 26 to define the spatial zone 20 (cf. Fig. 3). Optionally, in step 106 defining the spatial zone 20 at least one of the following second input information 5 is provided: a dimension parameter 73 of the robot device 70, information 33 on the at least one exposed body region 32.

[0051] Optionally, the step 106 of defining the spatial zone 20 involves the step 107 of determining an environment information 77 that represents data of an application scenario environment 78 of the robot device 70 within the spatial zone 20. The determined environment information 77 may provided by using means of visualisation for a further human input. The means of visualization may provide analysis results and guidance to the user 80, e.g. on the (graphic) robot teach device 40 (cf. Fig. 2), or by using a so-called augmented reality interface.

[0052] The environment information 77 may be generated by using a sensing device, e.g. a 3D scanning device or 3D sensor device to build a corresponding 3D model of the environment of the robot device 70. The guided-movement information 22 in combination with a computer program may also be used to generate the environment information 77.

[0053] In a third step 108, a contact configuration information 30 for a defined contact situation is provided that determines at least an exposed body region 32 to estimate a potential contact area 34 within the determined spatial zone 20.

[0054] In this context, it is important to note that “configuration” may be used in a very specific meaning:

[0055] • Constrained configuration - A contact situation in which the human body region cannot recoil or back away from the contact with the robot because there is a blocking obstacle that “constrains” such motion of the human.

[0056] • Unconstrained configuration - A contact situation in which the human body region is able to back away or recoil from a contact with the robot. There are no obstacles to prevent such motion. In the occurrences of the term further above and in some instances below, the term “configuration” may also be assumed to be the more general “provision or arrangement of information”.

[0057] In this context, it should be further noted: An also to look up the correct biomechanical loading limit values for the exposed body region. This is part of the simplification - it is not longer necessary to choose or enter manually a value for a biomechanical loading limit to be used. The exposed body region is used to perform this lookup in a table of values stored in the computer system that runs the method.

[0058] As an additional thought, this also allows updating the stored tables whenever new values are available from injury mechanics research. Thus, the configuration of the robot application need not be changed, since it contains only the choice of body region as a “lookup address” into the loading limit data stored in the computer system.

[0059] It is true, of course, that knowing the body region contributes to the possibility of estimating the contact area (e.g. in cmA2). The geometry of the part of the robot system involved in the contact is also relevant for this estimate.

[0060] For completeness, the details of the contact region on the robot system must still be provided. Lacking at present a better solution, these must still be provided numerically. A separate new method would be needed to render the input of this data simpler for the user.

[0061] Knowledge of the exposed body region and of the geometry e.g. radius of curvature of the region on the robot system involved in the contact then allows for a computational estimate of the actual contact area in the possible collision event. This calculation is implemented in the computer system implementing the method.

[0062] Optionally, in step 108 of providing the contact configuration information 30, a robot control system 75 and I or an external sensing device 85 connected to the robot control system 75 is used to provide the contact configuration information 30. The contact configuration information 30 may provided by the user 80 and I or automatically by using the control system 75 and I or the external (application) device 85.

[0063] The contact information 30 may be a constrained or an unconstrained contact information.

[0064] In a fourth step 110, at least one safety parameter 62 for configuring the safety zone 60 for the robot device 70 is determined on basis of the determined spatial zone 20 and the contact configuration information 30, e.g. constrained or unconstrained, for the defined contact situation.

[0065] In this way, a possible use of a geometric model of the robotic application setup may covered or provided, which might reside on an external computer. In a further embodiment of the present invention, also the possibility of using an imaging sensor system (e.g. 2D, 3D sensor) is covered to generate image(s) of the robotic setup and to analyze these information obtained to identify or to detail at least some further parts of the contact information.

[0066] In this respect, the following aspect may be considered as a further embodiment of the present invention regarding the robot device 70:

[0067] The robot device 70 has a robot control system 75 (cf. Fig. 2) that may consist of of a functional controller and safety controller. The functional controller is able to plan and execute motion, the safety controller is only able to observe the motion and to decide whether to let it continue.

[0068] If the safety controller decides that the motion shall not continue the only influence it can take is to trigger a transition to the safe state. The safe state is reached by executing a protective stop command and disconnecting drive energy from the actuators.

[0069] To reach its decision whether to let the functional controller continue its actions, the safety controller evaluates one or several conditions that involve quantities related to the robot motion. When all conditions are fulfilled, motion can continue, when at least one condition is violated, a transition to the safe state will be triggered.

[0070] Thus, the calculation of a “movement parameter” can take the form given as an example, namely limit values on movement related quantities. This calculation would thus be executed on the safety controller, so that the result can be used there.

[0071] The calculation of a movement parameter 74 might also be a programmed speed to use, which would be a result that can only reasonably be used by the functional controller to implement an adaptive I preemptive motion that seeks to avoid triggering a supervision condition in the safety controller.

[0072] Optionally, the step 110 of determining of the at least one safety parameter 62 includes calculating a movement parameter 74 for the robot device 70. The movement parameter 74 may be for example at least a value for a limit or a threshold for a contact force of the robot device 70, pressure value, speed limit value, effective mass value, spring constraint for manipulator 71 of the robot device 70.

[0073] The spatial zone 20 and the safety zone 60 according to the present invention may be the same, but in a possible embodiment, the spatial zone 20 of the robot device 70 may be defined as a working area of the robot device 70. Within the working area of the robot device 70, at least one safety zone 60 for the robot device 70 is determined or is part the working area, in which the robot device 70 has to move according to a determined safety function to reduce the risk of mechanical injuries for an user. This may mean also for example that with using PFL contact is allowed, but only with a limited contact force of the robot device.

[0074] Optionally, before the step 104, a step 102 is performed, determining a contact information 2 about at least one potential contact situation that is used as a first input information 3 for defining the at least one location 10 of the potential contact hazard for the robot device 70. Optionally, the contact information 2 is at least partly provided by the human instructor 80 and / or by an application device 82.

[0075] Optionally, for each contact situation at least the steps 104 and 106 are performed. In an embodiment, also the step 108 may be performed as well.

[0076] Fig. 2 illustrates a schematic overview of the robot device and robot system according to an embodiment of the present invention.

[0077] The robot system comprises the robot device 70 having a robot manipulator 71 and at least a component or part 72 that may be embodied as a robot end-effector and further, a robot control system 75 that may split optionally in a safety controller and a functional controller.

[0078] A robot teach pedant device 40 that be be embodied as an additional application device 82 is connected in a wired or wireless manner with the robot control system 75 of the robot device 70.

[0079] The human operator or user 80 may use the teach pedant device 40 that supports him in various ways to perform the kinesthetic lead-through approach to generate the guided-movement information 22, e.g. by displaying various values for defining the (pre-configured) spatial zone 20 around or within the application periphery 86. The teach pedant device 40 may also record the movements of the user 80 to define the spatial zone 20. The spatial zone 20 may involve at least an area of a safety zone 60 for the robot device 70. The user 80 may define certain safety zones 60 of the robot device 70 by performing the kinesthetic lead-through approach.

[0080] Further, information for an potential contact area 34 with information 32 on an exposed body region 33 may be provided by the teach pedant device 40 for support when determining the spatial zone 20 of the robot device. Further, the information for an potential contact area 34 with information 32 on an exposed body region 33 may also at least partly generated by the user 80 performing the kinesthetic lead-through approach and by moving the robot device 70 or a part of it 72 from a first position to a second position of the spatial zone 20.

[0081] A sensing device 85 may provide additional information, e.g. in form of 2D or 3D model data, to the robot control system 75 of the robot device 70, to the teach pendant device 40 and / or to the user 80 to better define the workspace or working area of the robot device 70 depending on a required safety requirement and / or a required application scenario for the robot device 70.

[0082] Fig. 3 illustrates a schematic example for positioning the robot device 70 by a human operator 80 according to an embodiment of the present invention. As described before in detail, the user 80 moves a part 72 of the robot device 70 from a first position 24 (left Figure of Fig. 3) to a second position 26 (right Figure of Fig. 3) to determine a spatial zone 20 of the robot device 70. In this way, at least a contact area 34 of an exposed body region of a potential user with a part 72 of the robot device 70 within the spatial zone 20 that may include at least a safety zone 60 may be considered and I or determined.

[0083] Fig. 4 illustrates a schematic flow-diagram 200 for generating a safety configuration for a robot device according to a further embodiment of the present invention by means of a computer system including a corresponding computer program using a robot device 70 (cf. Fig. 2).

[0084] A safety configuration may include configuring a parameter for a safety zone 60 and I or a safety function for the robot device 70 within the at least partly by a user 80 determined spatial zone 20.

[0085] In step 210, the user creates (mental) list of all relevant contact situations.

[0086] In step 220, for each contact situation as determined in step 210, the steps of 230 and 240 are performed.

[0087] In step 230, the user moves the robot to a location of contact hazard, e.g. using lead- through approach. In step 240, the user inputs the following information: contact configuration, exposed body region, contact area between an exposed body region of a user and a part of the robot device.

[0088] In step 250, it is asked, whether more contact situations should be included, If, yes, step 220 is performed, if no, step 260 is performed.

[0089] In step 260, when the input information is complete, a safety function parameter or a safety zone parameter configuration is calculated.

[0090] In step 270, the PFL configuration is completed and finished.

[0091] In the context of the workflow as described in Fig. 4, in the following, an example of an easy PFL safety zone or safety function configuration is provided, wherein the following data are provided and calculations may be performed:

[0092] For each contact case with its contact pose or safety zone, configuration (constrained I unconstrained), exposed body region(s), average contact area the following calculations are performed with the following steps (the order of the steps 1 to 4 may change depending on a certain application scenario):

[0093] 1. Compute effective mass of manipulator (and optionally effective spring constant of manipulator) at contact pose

[0094] 2. Look up effective mass and effective spring constant of exposed body region(s)

[0095] 3. Look up maximum contact forces and contact pressures for exposed body region

[0096] 4. Compute reduced mass, reduced spring constant in center-of-mass coordinates of equivalent two-body system

[0097] 5. As a result of the computations under steps or items 1 to 4: Compute determining quantity, force or pressure limits of robot device in a defined application scenario

[0098] 6. After determining the movement limit parameters of the robot device in step 5, a safety zone I safety function configuration can determined:

[0099] Unconstrained transient contact: Set speed limit in hazard zone or Constrained transient contact: Set speed limit, contact force limit in hazard zone

[0100] Fig. 5 illustrates another schematic flow-diagram for generating a safety configuration for a robot device according to an embodiment of the present invention.

[0101] In step 300, a starting point with data on at least a certain contact situation of the user with the robot device is defined.

[0102] In step 310, effective mass, spring const, for manipulator of the robot is determined.

[0103] In step 320, effective mass, spring const, for body region is determined.

[0104] In step 330, look up of limit thresholds for contact force, pressure value of the robot device.

[0105] In step 340, computation of reduced mass, spring const, of 2-body system.

[0106] In step 350, determination of limiting quantity, force or pressure for the robot device.

[0107] In step 360, selection of unconstrained vs. constrained configuration for the robot device.

[0108] In step 370, computation of speed limit for unconstrained case.

[0109] In step 380, computation of speed limit for constrained case.

[0110] In the following, further aspects of the present invention are detailed with reference to Fig. 1 to 3:

[0111] An important aspect of the present invention is to use a kinesthetic lead-through approach to define a PFL safety zone for a robot device and then, for fine-tuning the safety zone configuration, subsequently automatically calculating the corresponding configuration parameters for that safety zone. The kinesthetic lead-through approach means that the human operator or a user performs a guided-movement with a component or part of the robot device showing the robot device portions of the robot workspace that are relevant for setting up a safety zone configuration. In this way, the information input from the human operator can be limited to minimum level possible when setting up a safety zone configuration for the robot device.

[0112] For this, the human operator needs to specify and consider the following aspects based on the potential PFL-relevant contacts cases in mind:

[0113] - the location of a potential contact hazard,

[0114] - the configuration of the hazard (constrained I unconstrained),

[0115] - the body region(s) of a human potentially exposed to the contact hazard,

[0116] - and the details of the contact location (contact surface area, e.g. in cm2). As a future option it might be possible to consider also whether or not the contact location is padded. In this context, the determined contact data may also be displayed on a pedant display for the user.

[0117] When performing the kinesthetic lead-through approach, the user may interact with an application running on a so-called teach pendant device 40 of the robot system 70. The user or human operator employs the lead-through functionality of the robot device or robot system to identify the location and the extent of the spatial zone associated with a contact hazard.

[0118] The robot device is moved by the human operator to the relevant position(s) or to approximate contact poses that can be recorded as pose data which may be displayed on a pedant display or the like. The control system of the robot device can then read the position(s) of the robot manipulator. In this way, the (manual) input of numerical coordinate data by a user for safety zone or safety function configuration is avoided.

[0119] The approach of the present invention utilizes the lead-through functionality of collaborative robots to teach the coordinates of the PFL security zone(s) of a robot device and to calculate automatically the corresponding configuration parameters for the PFL safety functions. Then, the pendant application receives the qualitative input according to the points listed above:

[0120] - the configuration(s) of the contact(s) (e.g. constrained or unconstrained),

[0121] - the exposed body region (e.g. selected graphically from a body map),

[0122] - and the contact area (e.g. a number).

[0123] Sensible default values can be suggested. The computations needed to derive the choices of safety functions for PFL risk reduction and the values of the configuration parameters are carried out internally in the robot control system or pendant system. By default, these computations are hidden from the user to avoid unnecessary sensations of complexity.

[0124] By moving the robot TCP and recording positions and joint values significant positions relevant for clamping (constrained) situations are recorded and exposed body parts are specified.

[0125] Significant positions relevant for transient (unconstrained) contacts are recorded, specifying information 33 of exposed body parts 32 of a user 80 working with the robot device 70.

[0126] Based on these location and position recordings for a component or part 72 of the robot device 70, one or more safety zones 60 are at least partly automatically generated. The required force thresholds (based on type of contact, involved body part, etc.) are determined and the velocity limits are calculated, where the effective mass of the robots manipulator at the relevant positions can be obtained from the dynamics model of the manipulator 71 of the robot device 70.

[0127] For supporting the user 80 in this process, a graphical user interface may guide the user through the process of position teaching, parameterizing, verification, with visualization of the zones and relevant parameters. In this context, approaches such as “augmented reality” visualization, lead-through digitalization of curvatures of corners and edges and use it for contact force estimation or CAD-based complementation of zone data may be used to support the human operator to configurate a corresponding safety zone or a safety function parameter for a safety function for the robot device used in a required application scenario.

[0128] In the following, for a better understanding of the present invention, further information in the context of the present invention are described:

[0129] The most important characteristics for describing the scenario of a contact event of a robot incident onto a human body region can be grouped one of two categories:

[0130] • Setup-related - features related to the physical setup and the possible physical human-robot interactions

[0131] • Operation-related - features related to the motion of the robot

[0132] The setup-related parameters include:

[0133] • Contact configuration - expresses the possibility of backing away from the contact situation. The possible cases are: o Constrained - A contact situation in which the human body region cannot recoil or back away from the contact with the robot because there is a blocking obstacle that “constrains” such motion of the human. o Unconstrained - A contact situation in which the human body region is able to back away or recoil from a contact with the robot. In this case there are no obstacles to prevent such motion.

[0134] • Exposed body region - denotes the part of the human body subject to a contact from the moving robot system. It is important to resolve contact situations for the body region affected since the allowable force and pressure levels differ across the regions of the body. For purposes of estimating contact severity, the body region is characterized by its effective mass (relevant for unconstrained contact) and by its effective spring constant.

[0135] • Contact pose - expresses the position of the robot in the anticipated possible contact situation. For this robot pose (= collection of all joint positions), the moving robot has a certain effective mass (also referred to as reflected inertia or equivalent mass) in the direction of motion incident onto the human body region. Furthermore, in this pose, the robot manipulator has a certain effective spring constant that describes its elasticity in the direction of impact.

[0136] • Contact area - expresses the surface area over which the part of the robot system and the exposed region of the human body are in physical contact. Note that this area evolves over the duration of the contact. Usually, an average contact area is used in descriptions of the specific contact scenario and in estimations of its severity. Note that this area depends on the geometry and material properties of both the participating part of the robot and the human body region involved.

[0137] The operation-related parameters include:

[0138] • Robot speed - expresses the speed of the part of the robot that impacts the human body region. A specific speed value might be acceptable or might be too high considering the possible harm it could cause to the human body region. Supervision and limiting of robot speed by the robot control system is possible in defined regions of the workspace (zones).

[0139] • Robot position - expresses the position of the part of the robot that could be involved in a contact with a body region of the human operator. A specific position might be either remote from a possible contact situation or might be close to such a situation. Supervision and limiting of the robot position by the robot control system is possible with respect to defined regions of the workspace (zones).

[0140] • Robot contact force - expresses the force that the part of the robot in contact with the environment is exerting onto the environment. This force consists of a contribution from inertial forces (due to the inertia of moving masses of the robot, which increase with increasing robot speed) and a contribution from driving forces (due to the drive train of the robot joints, which dominate when the robot speed is low or zero). Supervision and limiting of the contact force by the robot control system is possible once external contact begins.

[0141] • Robot orientation - expresses the orientation e.g. of the end-effector I tool mounted on the robot. The orientation can influence with side of the endeffector is presented in the case of a possible human-robot contact. When the contact area and / or the material properties of the contacting surfaces differ around the end-effector, this can influence the severity of the contact situation. The orientation of the end-effector can be supervised and limited by the robot control system.

[0142] The severity of potential contact events between the moving robot and regions of the human body is gauged by a combination of maximum contact force and maximum contact pressure [ref]. The collaborative robot application must be designed such that the maximum contact force and the maximum contact pressure are both respected in all reasonably expected contact situations in the application. Given the setup-related parameters, the task is to choose the appropriate operation-related parameters to accomplish this.

[0143] While it is possible to measure repeatedly the prospective contact forces and pressures in the contact situations reasonably expected as one adjusts the operation-related parameters, it can be helpful to make use of theoretical models [ref] of the contact situations that use the setup-related parameters and the operation-related parameters to compute estimates of the expected contact forces and pressures. Adjusting the parameters can then require fewer iterations until the contact force and pressure limits are obeyed.

[0144] The collection of setup-related parameters and operation-related parameters can be referred to as a “configuration” or “PFL configuration” for the supervision and limiting functions (safety functions) used to reduce the risk according to the PFL method.

[0145] In the following, the most important aspects of the present invention are summarized:

[0146] - Use online lead-through function to define locations of contact hazards.

[0147] - To define extent of spatial zone around contact hazard, use lead-through approach. Optionally, by textual input. Optionally, by qualitative input. Optionally, by computation using dimensions of robot and / or models of robot environment. Optionally, by using information on exposed body region. - Use app running on teach pendant device (optionally robot control system, optionally external computer connected to control system) to input contact configuration (unconstrained, constrained), to select exposed body region(s), to enter estimated contact area(s).

[0148] - Compute parametrization for safety function(s) to reduce risk in area in question.

[0149] -zz-

[0150] Reference signs

[0151] 2 contact information

[0152] 3 First input information

[0153] 5 Second input information

[0154] 10 Location I Location area

[0155] 20 Spatial zone

[0156] 22 (real-time) guided-movement input information

[0157] 24 First position

[0158] 26 Second position

[0159] 30 Contact configuration information

[0160] 32 Exposed body region

[0161] 33 Information on an exposed body region

[0162] 34 Contact area

[0163] 40 Robot teach pedant device

[0164] 60 Safety zone

[0165] 62 Safety parameter

[0166] 70 Robot device I Robot system

[0167] 71 Robot manipulator

[0168] 72 Part I Component of the robot device I robot end-effector

[0169] 73 Dimension parameter

[0170] 74 Movement parameter

[0171] 75 Robot control system

[0172] 77 Environment information

[0173] 78 Environment

[0174] 80 Human instructor

[0175] 82 Application device

[0176] 85 Sensing device

[0177] 86 Application periphery Computer-implemented method

[0178] Determining

[0179] Defining

[0180] Determining

[0181] Determining

[0182] Providing

[0183] Determining

[0184] Workflow 1 for generating a safety configuration for a robot device

[0185] Relevant contact situations

[0186] For each contact situation

[0187] Moving robot device to location of contact hazard

[0188] Providing user input

[0189] Decision-tree

[0190] Computation

[0191] Outputting result

[0192] Workflow 2 for generating a safety configuration for a robot device

[0193] Determination

[0194] Determination

[0195] Look up

[0196] Computation

[0197] Determination

[0198] Selection

[0199] Computation

[0200] Computation

Claims

Claims:1 . Method (100) for configuring at least a safety parameter (62) for a safety zone (60) for a robot device (70), comprising:- Defining (104) at least a location (10) of a potential contact hazard for the robot device (70);- Determining (106) a spatial zone (20) around the defined location (10) by using at least partly a real-time guided-movement input information (22) provided by a human instructor (80), wherein guided-movement information (22) is generated in that the human instructor (80) moves at least a component (72) of the robot device (70) from a first position (24) to a second target position (26) to define the spatial zone (20);- Providing (108) a contact configuration information (30) for a defined contact situation, that determines at least an exposed body region (32) to estimate a potential contact area (34) within the determined spatial zone (20);- Determining (110) at least one safety parameter (62) for configuring the safety zone (60) for the robot device (70) on basis of the determined spatial zone (20) and the contact configuration information (30) for the defined contact situation.

2. Method (100) according to claim 1 , wherein before the step (104), a step (102) is performed, determining a contact information (2) about at least one potential contact situation that is used as a first input information (3) for defining the at least one location (10) of the potential contact hazard for the robot device (70).

3. Method (100) according to claim 2, wherein the contact information (2) is at least partly provided by the human instructor (80) and I or by an application device (82).

4. Method (100) according to one of the previous claims, wherein for each contact situation the steps (104) and (106) are performed.

5. Method (100) according to one of the previous claims, wherein in step (106) defining the spatial zone (20) at least one of the following second input information (5) is provided: a dimension parameter (73) of the robot device (70), information (33) on the at least one exposed body region (32).

6. Method (100) according to one of the previous claims, wherein in step (108) of providing the contact configuration information (30), a robot control system (75) and I or an external sensing device (85) connected to the robot control system (75) is used to provide the contact configuration information (30).

7. Method (100) according to one of the previous claims, wherein the step (110) of determining of the at least one safety parameter (62) includes calculating a movement parameter (74) for the robot device (70).

8. Method (100) according to one of the previous claims, wherein the step (106) of defining the spatial zone (20) involves the step (107) of determining an environment information (77) that represents data of an application scenario environment (78) of the robot device (70) within the spatial zone (20).

9. Method (100) according to claim 8, wherein the determined environment information (77) is provided by using means of visualisation for a further human input.

10. Computer system configured to execute the method (100) according to any of the previous method claims 1 to 9 for configuring a safety zone (60) or a safety function for a robot device (70).11 . A computer comprising a processor configured to perform the method of any preceding claims 1 to 9.

12. A computer program product comprising instructions which, when the computer program is executed by a processor of a computer, causes the computer to perform the method of any of claims 1 to 9.

13. Machine-readable data medium and I or download product containing the computer program according to claim 12.

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