阅读说明：本技术 机器人的控制 (Control of a robot ) 是由 Y·库甘 于 2018-05-14 设计创作，主要内容包括：一种根据本发明的用于控制机器人(1)的方法,具有以下步骤：预先给定(S10)施加到接触部位(2；2’)上的额定力(F<Sub>s</Sub>)；确定(S20)所述接触部位处的接触刚性(c；c’)；和根据所确定的接触刚性通过正在运动的机器人的驱动器(5)和/或制动器使正在运动的机器人制动(S50),以便通过正在停止和/或已停止的机器人将所述额定力施加到所述接触部位上,其中,在达到(x<Sub>s</Sub>；x’<Sub>s</Sub>)所述额定力之前,开始所述制动(x<Sub>b</Sub>,x’<Sub>b</Sub>)。(A method according to the invention for controlling a robot (1) has the following steps: predetermining (S10) a defined force (F) to be applied to the contact point (2; 2 s ) (ii) a Determining (S20) a contact stiffness (c; c') at the contact site; and braking (S50) the moving robot by means of the drive (5) and/or brake of the moving robot as a function of the determined contact rigidity in order to apply the nominal force to the contact point by means of the stopping and/or stopped robot, wherein (x) is reached s ；x’ s ) Before the rated force, the braking (x) is started b ，x’ b )。)

1. A method for controlling a robot (1) having the steps of:

-predetermining (S10) a set force (F) acting on the contact point (2; 2')_s)；

-determining (S20) a contact rigidity (c; c') at the contact site; and

-braking (S50) the moving robot by means of the drive (5) and/or brake of the moving robot in accordance with the determined contact rigidity in order to apply the nominal force to the contact location by means of the stopping and/or stopped robot, wherein, when (x) is reached_s；x’_s) Before the rated force, the braking (x) is started_b，x’_b)。

2. Method according to claim 1, characterized by the steps of:

-detecting (S30) a current contact or an upcoming contact (x) of the contact location by the moving robot_c) Wherein the moving robot is braked by its drive and/or brake in dependence of the detected contact in order to apply the rated force to the contact location by the stopping and/or stopped robot.

3. Method according to any of the preceding claims, characterized in that in the moving robot contact (x)_c) (x ') the moving robot is started by a drive and/or a brake of the moving robot before the contact point, if necessary'_b) Braking in order to apply the nominal force to the contact points by the stopping and/or stopped robot.

4. Method according to any of the preceding claims, characterized in that in the moving robot contact (x)_c) After the contact point, if necessary (x)_b) Braking the moving robot by means of a drive and/or a brake of the moving robot in order to apply the nominal force to the contact point by means of the stopping and/or stopped robot.

5. Method according to any of the preceding claims 2-4, characterized in that a reaction force between the contact location and a robot contacting the contact location is detected, and that the current contact is detected on the basis of the reaction force.

6. Method according to any of the preceding claims 2-5, characterized in that the distance between the robot and the contact site is detected and that a current and/or upcoming contact is detected based on this distance.

7. Method according to any of the preceding claims, characterized by the steps of:

-detecting a current movement of the robot, wherein the moving robot is braked by its drives and/or brakes in accordance with the detected movement, in particular in accordance with a model of the robot, in order to apply a nominal force to the contact points by the stopping and/or stopped robot.

8. Method according to any one of the preceding claims, characterized in that the rigidity (c) of the contact site is determined according to₂；c’₂) And/or the rigidity of the robot (c)₁) The contact rigidity is determined.

9. Method according to any of the preceding claims, characterized in that at least one reaction force between the robot and the contact site and/or its surroundings is detected and the contact rigidity is determined on the basis of this reaction force.

10. Method according to claim 9, characterized in that the reaction force is detected and the contact stiffness is determined on the basis of the reaction force during the time when the robot has contacted the contact location for applying the nominal force by the stopping and/or stopped robot.

11. Method according to claim 9, characterized in that the robot contacts the contact site and/or its surroundings in one or more tests and here detects a reaction force and determines the contact rigidity on the basis of this reaction force, whereafter the robot re-contacts the contact site in order to exert the rated force by the stopping and/or stopped robot.

12. Method according to any of the preceding claims, characterized in that the contact rigidity is determined according to the pose of the robot.

13. A controller (3) for controlling a robot (1), arranged for performing the method according to any of the preceding claims, and/or having:

-for predetermining a set force (F) acting on the contact point (2; 2')_s) The apparatus of (1);

-means for determining the contact rigidity (c; c') at said contact site; and

-means for braking the moving robot by means of the drive (5) and/or brake of the moving robot in accordance with the determined contact rigidity in order to apply the nominal force to the contact point by means of the stopping and/or stopped robot, wherein (x) is reached_s；x’_s) Before the rated force, the braking (x) is started_b，x’_b)。

14. Installation with a robot (1) and a controller (3) for controlling the robot according to the preceding claim.

15. A computer program product having a program code stored on a computer readable medium for performing the method according to any of the preceding claims.

Technical Field

The invention relates to a method and a controller for controlling a robot, and to a plant with a robot and a controller, and to a computer program product for carrying out the method.

Background

It is known from practice within an enterprise to predetermine a nominal force which the robot should exert on the contact site and then to detect the current reaction force between the robot and the contact site during operation of the robot. Once it is detected that the reaction force has reached the nominal force, the robot is braked by its drive and/or brake.

In particular, the robot can thus also operate in unknown or changing environments, for example, approach a workpiece with a changing position and stop upon contact, for example, in order to clamp, machine, etc. the workpiece.

However, the robot is also operated subsequently, in particular due to mechanical, electronic and/or control-technical inertia or a fault time, so that the robot is stopped with a certain delay only after the detection of the applied or reached setpoint force.

In this case, however, the robot can penetrate deeper into the contact region or in particular elastically and/or plastically deform the surroundings of the contact region, wherein the actual reaction force is undesirably increased beyond a predefined setpoint force.

Accordingly, the speed of the robot has hitherto been reduced before the contact point is contacted by the moving robot, in order to reduce the momentum of the robot and the consequent follow-up and the increase in reaction forces associated therewith.

Disclosure of Invention

The aim of the invention is to improve the operation of a robot.

This object is solved by a method having the features of claim 1. Claims 13 to 15 protect a controller and a computer program product for carrying out the method described herein or a plant with a robot and a controller described herein. The dependent claims relate to advantageous developments.

According to an embodiment of the invention, a method for controlling a robot has the following steps:

-predetermining a nominal force to be applied to the contact site;

-determining a contact stiffness at the contact site; and

braking the moving robot by means of the drive and/or brake of the moving robot on the basis of or as a function of the determined contact rigidity in order to apply or impart a setpoint force to the contact point by means of the stopping and/or stopped robot or in such a way that the stopping or stopped robot applies or imparts the setpoint force to the contact point, in particular at least, at most and/or with a certain tolerance, wherein the braking is started before the setpoint force is reached.

By braking the robot on the basis of a contact stiffness determined beforehand and/or during contact, or taking this into account during braking, and starting the braking already here or thus before the setpoint force is reached, and thus reducing and preferably at least substantially avoiding subsequent operation of the robot with a corresponding force excess above the setpoint force, it is possible in one embodiment to improve the consistency of the reaction force which the stopped or stopped robot actually finally exerts on the contact point with the predefined setpoint force, and/or to move the robot also at a higher speed in the vicinity of the contact point, and thus in particular to reduce the cycle time.

In one embodiment, the robot has at least three, in particular at least six, in particular at least seven (movement) axes or joints, which are brakable, in particular arrestable, or (can) be brakable, in particular arrestable, in particular by being controlled by the drives and/or brakes of the robot.

For a more compact description, in the sense of the present invention, a control based on a (control) difference between a setpoint value and a (detected) actual value is also referred to as a control in the present invention. In the sense of the present invention, a force can also include, in general terms, in particular an antiparallel couple, i.e. a (rotational) moment. In the context of the present invention, rigidity is understood in particular in a manner customary in the art as the relationship between the depth of penetration or in particular elastic and/or plastic deformation and the force required or applied for this purpose, in particular the quotient of the force divided by the depth of penetration or deformation.

In one embodiment, the stopping or stopped robot applies a counterforce or a setpoint force to the contact point via the robot-guided tool or workpiece, or is provided or set up for this purpose.

In an embodiment, braking of the moving robot by the drive and/or brake of the moving robot for applying the rated force comprises: correspondingly (operating) controlling, in particular adjusting, the drive or brake accordingly; depending on the determined contact rigidity and the predefined setpoint force, in particular a setpoint position of the stopped or stopped robot is determined and/or commanded, in which the robot applies or is to apply the predefined setpoint force to the contact point, and/or in particular a setpoint movement, in particular a setpoint speed (course) and/or a setpoint acceleration (course) is determined and/or commanded.

In particular, in one embodiment, the moving robot is stopped or stationary in a first position by means of a drive and/or brake of the moving robot to apply a defined force if the contact rigidity has a first value or is determined accordingly, and the moving robot is stopped in a second position if the contact rigidity has a second value or is determined accordingly that is smaller than the first value, in which second position the moving robot, in particular a robot-guided tool or workpiece, penetrates deeper into the contact region or reaches a greater deformation.

In one embodiment, if the contact rigidity has a first value or is respectively determined, braking by the drive and/or brake for applying the setpoint force is started at a first point in time before the setpoint force is reached, and if the contact rigidity has or is respectively determined to be a second value which is smaller than the first value, braking by the drive and/or brake is started at a later second point in time before the setpoint force is reached, in particular in the case of a first value of the contact rigidity, braking by the drive and/or brake is initiated, in particular commanded, at the first point in time, and if the contact rigidity has the second value, braking by the drive and/or brake is initiated or commanded at the second point in time.

Additionally or alternatively, in one embodiment, the robot is braked or delayed more strongly by its drive and/or brake for applying the set force in at least one phase if the contact rigidity has or is determined accordingly to be a first value or said first value, and is braked or delayed less strongly in at least this phase if the contact rigidity has or is determined accordingly to be a second value or said second value which is smaller than the first value.

In one embodiment, the method comprises the steps of: the contact location is detected from a current contact or an imminent contact of the moving robot, in particular the beginning or the end of the contact between the robot and the contact location, wherein the moving robot is braked by its drive and/or brake based on or (also) depending on the detected contact, in order to apply a nominal force to the contact location by the stopping or stopped robot.

The reaction force between the robot and the contact point or the reaction force exerted by or imparted on the contact point by the robot depends on the one hand on the contact rigidity and on the other hand on the penetration depth or, in particular, on the elastic and/or plastic deformation, which penetration depth or deformation itself depends on the difference between the pose of the robot and the pose of the robot when contacting the contact point or the pose of the robot when the contact between the robot and the contact point starts or ends, for example according to the spring law, with the general formula F ═ F_c(x-x_c) In particular the linear spring law F ═ c · (x-x)_c) Having a contact stiffness function f_cOr the contact stiffness factor c, the current position of the robot contact area x and its position x at the time of contact_c. Accordingly, in an embodiment, by braking the moving robot, in particular stopping in the first or second pose, starting the braking at the first or second point in time and/or braking more or less strongly depending on the detected contact, a subsequent operation of the robot with a corresponding force excess can be reduced and preferably at least substantially avoided, and thus the stopping or stopped robot is improvedThe reaction force which is ultimately actually applied to the contact point corresponds to the predefined setpoint force and/or the robot also moves at a higher speed in the vicinity of the contact point, and therefore the cycle time is reduced in particular.

In one embodiment, the braking of the moving robot by the drive and/or brake of the moving robot is optionally already started before the moving robot comes into contact with the contact point for this purpose, in order to apply a setpoint force to the contact point by the stopping or stopped robot. In one embodiment, this makes it possible to avoid the robot from intruding too far with a correspondingly large force superelevation that exceeds the rated force, even when the contact rigidity and/or the approach speed are high.

In addition or alternatively, the braking of the moving robot by the drive and/or brake of the moving robot is started if necessary after the moving robot has contacted the contact point for this purpose, in order to apply a nominal force to the contact point by the stopping or stopped robot. Thus, in an embodiment, by detecting a reaction force between a contact site and a robot contacting the contact site, it is possible to detect a current contact based on the reaction force and/or determine contact rigidity based on the reaction force.

In one embodiment, a reaction force between the contact location and the robot contacting the contact location is detected and the current contact is detected on the basis of the reaction force, in particular as soon as the reaction force exceeds a predefined threshold value or detects this. In one embodiment, the current contact can thus be detected precisely and/or by means of a corresponding force sensor of the robot.

Additionally or alternatively, in one embodiment, the distance between the robot and the contact point is detected, in particular by means of at least one robot-guided and/or at least one sensor spaced apart from the robot, in particular an (at least) electrical, magnetic and/or optical sensor, in particular a (at least) camera, and the current and/or imminent contact is detected on the basis of the distance. In one embodiment, it is thus possible to detect an imminent contact and thus to initiate braking particularly early. Additionally or alternatively, in one embodiment, a desired setpoint force can thus be applied to the contact point by the robot even without a force sensor.

In one embodiment, the method comprises the steps of: the current movement, in particular the speed and/or the acceleration of the robot is detected, wherein the moving robot is braked by means of the drive and/or the brake of the moving robot in accordance with (also) the detected movement, in particular in accordance with a, in particular mathematical (surrogate) model of the robot, in order to apply a nominal force to the contact points by the stopping or stopped robot. In this way, the braking of the robot can advantageously be carried out (more) precisely, in particular with model-supported pre-control and/or regulation, so that the robot is stopped in a position in which it exerts a desired force on the contact point and which accordingly depends on the contact rigidity, wherein in one embodiment the contact rigidity is taken into account in the model.

In particular in one embodiment, if the robot, in particular the robot contact area, has a first speed upon contact, the moving robot is braked more strongly by its drive and/or brake in at least one phase for applying a set force and/or starts braking by the drive and/or brake at a first point in time for applying a set force, and if the robot (contact area) has a second speed upon contact which is less than the first speed, the moving robot is braked less strongly in at least this phase and/or starts braking at a later second point in time, because the reaction force increases more rapidly when the contact speed is greater.

In one embodiment, the contact rigidity is determined as a function of the rigidity of the contact point and/or the rigidity of the robot, in particular so that in one embodiment the flexibility, in particular the elasticity, of the entire system consisting of the contact point and the robot is taken into account. In this way, the braking of the robot is advantageously (more) precisely performed, so that the robot is stopped in an attitude in which the robot exerts a nominal force on the contact point and the attitude is accordingly dependent on the contact rigidity. In contrast, if the contact rigidity is determined independently of the rigidity of the contact site or independently of the rigidity of the robot, this may simplify its determination in an embodiment.

In one embodiment, the contact rigidity is determined, in particular estimated, theoretically, in particular numerically, in particular by simulation, in particular on the basis of or as a function of known material and/or geometric parameters of the contact point and/or of the robot.

Additionally or alternatively, the contact stiffness may in an embodiment be determined empirically, in particular by detecting reaction forces between the contact site and the robot contacting the contact site and/or one or more reaction forces between the surroundings of the contact site and the robot contacting the surroundings, and determining the contact stiffness based on these detected reaction forces. In one embodiment, the reaction forces between the contact point or the surroundings and the robot are detected by a force sensor device of the robot, in particular one or more force sensors in the joints of the robot and/or on its robot flange or tool flange, wherein, as mentioned above, the forces may also comprise moments, so that in the sense of the present invention the force sensors in particular also comprise moment sensors.

In one embodiment, the contact rigidity can thus advantageously be determined (more) precisely and/or online.

In an embodiment, during the time when the robot has contacted the contact site for the purpose of applying a nominal force by the stopping or stopped robot, the reaction force is detected and the contact stiffness is determined based on the reaction force. Thereby, in an embodiment, the contact rigidity for the current contact location may be (more) accurately determined.

In another embodiment, the robot first contacts the contact site and/or its surroundings one or more times in a test mode. Here, the reaction force is (respectively) detected and the contact rigidity is determined on the basis of the reaction force or forces, in particular by averaging, interpolation and/or extrapolation or the like, before the robot then (re-) contacts the contact location for applying a nominal force by the stopped or stopped robot. In one embodiment, the contact rigidity can thus be determined beforehand and, in particular in the case of high contact rigidity and high approach speeds, too deep penetration of the robot with a correspondingly high force exceeding the rated force can be avoided.

In one embodiment, the contact rigidity is determined as a function of the pose of the robot, in particular selected from a plurality of pose-specific contact rigidities, which are determined in advance by the aforementioned test mode contact or intrusion, and/or interpolated and/or extrapolated. In one embodiment, it can thus be advantageously taken into account that the rigidity of the robot on the one hand and the contact point and thus its rigidity can be correlated with the posture of the robot on the other hand.

According to one embodiment of the invention, a controller, in particular hardware and/or software, in particular programming, for controlling a robot is provided for carrying out the method described herein and/or has:

-means for predetermining a nominal force to be applied to the contact site;

-means for determining the contact rigidity at the contact site; and

-means for braking the moving robot by means of the drive and/or brake of the moving robot in accordance with the determined contact rigidity in order to apply the nominal force to the contact location by means of the stopping and/or stopped robot, wherein the braking is started before the nominal force is reached.

In one embodiment, a controller or apparatus thereof has:

-means for detecting a current contact or an imminent contact of the contact location by the moving robot, wherein the moving robot is braked by its drive and/or brake in accordance with the detected contact in order to apply a nominal force to the contact location by the stopping and/or stopped robot;

-means for starting braking the moving robot by means of the drive and/or brake of the moving robot, if necessary before the moving robot contacts the contact location, in order to apply a nominal force to the contact location by means of the stopping and/or stopped robot;

-means for starting the braking of the moving robot by the drive and/or brake of the moving robot, if necessary after the moving robot has contacted the contact location, in order to apply a nominal force to the contact location by the stopping and/or stopped robot;

-means for detecting a reaction force between the contact location and the robot contacting it and detecting the current contact based on the reaction force;

-means for detecting a distance between the robot and the contact location and detecting a current and/or upcoming contact based on the distance;

means for detecting a current movement of the robot, wherein the moving robot is braked by its drive and/or brake depending on the detected movement, in particular depending on a model of the robot, in order to apply a nominal force to the contact points by the stopping and/or stopped robot;

-means for determining the contact rigidity from the rigidity of the contact site and/or of the robot;

-means for detecting at least one reaction force between the robot and the contact site and/or the surroundings and determining the contact stiffness based on the reaction force;

-means for detecting said reaction force and determining contact rigidity based on the reaction force during the time when the robot has contacted the contact location to apply the nominal force by the stopping and/or stopped robot;

-means for contacting the contact site and/or its surroundings by the robot in a test mode one or more times and detecting a reaction force there and determining a contact stiffness based on this reaction force before the robot re-contacts the contact site to apply the rated force by the stopping and/or stopped robot; and/or

-means for determining the contact stiffness from the pose of the robot.

A device in the sense of the present invention can be embodied in hardware and/or in software, in particular with a, in particular digital, processing unit, in particular a microprocessor unit (CPU), and/or one or more programs or program modules, which are preferably connected to a memory and/or a bus system data or signal. The CPU may be configured to process instructions implemented as a program stored in the memory system, detect input signals to the data bus, and/or send output signals onto the data bus. The storage system may have one or more, in particular different, storage media, in particular optical, magnetic, solid-state and/or other non-volatile media. The program may be provided such that it is capable of embodying or executing the methods described herein, such that the CPU is capable of performing the steps of such methods, and is thus particularly capable of controlling a robot.

In one embodiment, one or more, in particular all, steps of the method are performed fully or partially automatically, in particular by a controller or its device(s).

Drawings

Further advantages and features emerge from the dependent claims and the embodiments. This section shows schematically:

FIG. 1: a facility according to an embodiment of the present invention having a robot and a controller for controlling the robot;

FIG. 2: applying a reaction force or a rated force by the robot; and

FIG. 3: a method for controlling a robot according to an embodiment of the present invention.

Detailed Description

Fig. 1 shows a facility with a robot 1 and a controller 3 for controlling the robot 1 according to an embodiment of the invention, and fig. 3 shows a method for controlling the robot 1 implemented by the controller 3 according to an embodiment of the invention.

In step S10, a rated force F is given in advance_sThe robot should be able to move theA nominal force is applied to the contact points 2. This may be predefined or predefined, for example, by user input, a working program or procedure of the robot, etc. In one embodiment, the setpoint force can be predefined, in particular, by a stop condition in the operating program.

In step S20, which can also be carried out before, in parallel with or after step S10, the contact stiffness c at the contact point 2 is determined from the stiffness of the contact point 2 and the stiffness of the robot 1, in FIG. 1 by the spring stiffness c of the robot 1₁And spring rate c of contact portion 2₂To illustrate the contact rigidity and in this embodiment in a simplified manner byAnd (4) obtaining. At the other contact point 2', the contact rigidity is, for example

As in figure 1 by corresponding spring stiffness c'₂As shown briefly.

This determination of the contact rigidity c or c 'can be carried out, for example, by advancing the robot 1 in a test mode toward the contact point 2, 2' and penetrating the contact point with a predetermined, in particular varying, force and detecting the (corresponding) penetration depth there and/or conversely penetrating the robot 1 to a predetermined, in particular varying, penetration depth and detecting the (corresponding) reaction force there.

The contact rigidity can be determined in a specific manner for the contact location, for example by the above-described intrusion in a test mode, at the contact location 2And determining the contact stiffness at the contact location 2

Depending on the current contact location, the corresponding contact stiffness is then selected or an interpolation or extrapolation between a plurality of contact stiffnesses is carried out. Also, the same applies toIn the contact portions 2 and 2 ', the average contact rigidity (c + c')/2 can be determined uniformly. It is to be understood that the two contact points 2, 2' are used merely for a simplified illustration.

During the approach of the robot 1 to the contact point 2, the contact rigidity c can likewise be determined online, so that a defined force F is already exerted_sIn particular at the beginning of an intrusion, by comparing the depth of the intrusion with the reaction force detected in this case.

In step S30, a current or imminent contact x of the contact location 2 by the moving robot 1 is detected_c。

This can be done in particular by detecting a reaction force between the contact point 2 and the robot 1 contacting the contact point by means of a force sensor integrated in the drive 5 and/or a force sensor 5' on the flange of the robot 1 and detecting the current contact on the basis of the reaction force.

Likewise, the distance between the robot 1 and the contact point 2 can be detected by means of a robot-guided camera 4, which in one variant can also be spaced apart from the robot 1, and the current or imminent contact x can be detected on the basis of this distance_c。

Based on the setpoint force F predefined in step S10_sThe contact rigidity c determined in step S20, and the contact x detected in step S30_cThe controller 3 determines the rated attitude x of the robot 1 in step S40_sIn this nominal attitude, the robot exerts a nominal force F_s。

This is shown in fig. 2 in a simplified manner by means of a linear assumed or approximated model. As can be seen, in this embodiment by

Obtaining a nominal attitude x_s。

In step S50, the controller 3 brakes the robot 1 in motion by its driver 5 so that the robot 1 is in the rated posture x_sDown to rest and then in this nominal posture correspondingly apply the nominal force F_sIs applied toOn the contact site 2.

This can be particularly supported by the model taking into account the contact rigidity c and the movement dx/dt, d of the detection robot 1²x/dt²Is carried out in the case of (1). If the mass and the driving force of the robot are projected onto the mass m and the driving force F is projected onto the mass m in a simplified manner_xProjecting along the x-axis direction depicted in fig. 1, the model is then derived ignoring further forces such as friction, gravity, etc.:

thus, the velocity sum at x detected upon contact can be utilized_sThe required stop to determine and command the corresponding driving force.

However, it is not necessary to calculate the nominal attitude x_s. In one variant, for example, the speed of the robot 1 or its contact region during contact and the determined spring stiffness c can be determined, in particular model-supported, by predicting: when the rated force Fs is reached and the braking is started (earlier) or (later) accordingly and/or the braking is stronger or weaker, respectively, at least in a stepwise manner.

In the case of contact site 2, x is_sUnder the condition of (3) reaching a rated force F_sBefore, but first after the moving robot 1 contacts the contact site 2, at x_bBraking is initiated in this case.

Likewise, especially as through c'₂>c₂Exemplary schematic high contact stiffness case, robot also in motion at x_cIn case of x 'just before contact with contact site 2'_bIn such a way that the moving robot 1 starts braking by its drive 5 to bring the rated force F by the stopped robot_sIs applied to the contact site 2'.

This also illustrates that the contact stiffness may be chosen based on or according to the pose of the robot 1 or that interpolation or extrapolation between multiple contact stiffnesses may be performed. Depending on the position of the robot 1, the robot touches the contact point 2 or 2 ', so that in step S20 a position-specific contact stiffness c or c', respectively, can be selected. In another pose, interpolation or extrapolation from these contact stiffnesses c, c' can be performed.

While exemplary embodiments have been set forth in the foregoing description, it should be noted that a number of variations are possible. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, guidance is provided to the person skilled in the art from the preceding description for converting at least one exemplary embodiment, wherein various modifications may be made, particularly in matters of function and arrangement of the components set forth without departing from the scope of the claims and their equivalents.

List of reference numerals

1 robot

2. 2' contact site

3 controller

4 vidicon

5 drive with force or torque sensor

5' force or moment sensor

c contact rigidity

c₁Rigidity of robot 1

c₂、c’₂Rigidity of contact portion 2/2

F_sRated force

x_cContact with

x_sNominal posture

x_b、x’_bInitiation of braking