DE102016200455A1 - Safety device and method for safe operation of a robot - Google Patents

Abstract

The present invention provides a safety device and method for safely operating a robotic controlled robot in a work area. If a distance between the robot and a potential collision object is less than a calculated braking distance of the robot and if a calculated potential extent of damage is greater than a predetermined damage limit, the robot is shut down and at least one airbag installed in the robot is triggered. Thus, the security of the object located in the robot work area is ensured even in the event of a collision, whereby a close cooperation with the robot, in particular a direct human-robot cooperation (MRK), is made possible.

Description

The invention relates to a safety device for safe operation of a controlled controlled in a work area robot and a corresponding safety method. Furthermore, the invention relates to an industrial robot, with which such a safety device or such a safety method can be realized.

In robotics, there is an increasing need for people (without dividing walls or protective fences) to work hand in hand with robots. Such a direct "human-robot cooperation" (MRK) promises the economy new perspectives with regard to automation as well as more flexible production possibilities. Above all, the degree of automation can be made variable depending on the task.

In order to enable a direct MRC without risk, aspects that were previously irrelevant, because they were excluded thanks to the rigorous separation of humans and robots, have to be considered. Thus, due to the masses of robots, grippers, tools and workpieces, fast-moving industrial robots pose considerable risks to the life and limb of the persons entering the working area of the robots. The extent of potential harm to data subjects ranges from mild, usually reversible, injuries such as: B. cuts and bruises, over average, usually irreversible injuries, such. As amputations, up to serious or fatal injuries.

The highest safety requirements apply when robot and human work closely together, as in mounting or welding, since humans usually have a restricted field of view. As the robot moves or rotates the workpiece to the best possible position, there is a large spatial proximity between the subject and various robot elements (such as the robot arm or the workpiece guided by the robot). This can lead to a direct contact between the robot and the person.

In a human-robot collision, most injuries are caused by the human being bumping into hard, sharp, and fast-moving robot parts. In order to avoid such injuries, various safety sensors have been developed for sensory monitoring of the entire working range of the robot. If potential collision objects are detected in the work area, the collision avoidance or collision reduction can be actively intervened in the kinematics of the robot to limit the power and force in real time.

However, such safety sensors do not always work reliably and are therefore not able to completely eliminate the risk of human-robot collisions. Namely, in known safety concepts for collaborative operation, safety sensors are only used to detect the potential collision object in the robotic work area as well as the robot itself and then adapt the robot path and / or speed to the potential collision object for collision avoidance. However, such known security concepts only work properly if z. B. a respective operator with a very small and low-power lightweight robot (such as a mobile service robot) works together. However, in industrial robots that are designed for use in industrial environments (eg automobile manufacturing), these known safety concepts quickly reach their limits. The main reason for this is that, with regard to industrial robots, the following three decisive influencing factors for the occurrence of a collision and the extent of damage in such a collision have hitherto largely been disregarded: 1. mass of the robot; 2. speed of the robot; 3. Type (in particular surface shape) of the colliding robot parts or tools (eg sharp robot edge or corner) and object parts (eg human head).

in the Conference Paper "Safety Evaluation of Physical Human-Robot Interaction via Crash-Testing" by S. Haddadin et al., Published in Proceedings of the Robotics Science and Systems Conference (RSS), Atlanta, GA, USA, Jun. 2007, pp. 217-224 , is already taught to assess human safety during physical interaction with the robot through collision tests ("crash tests") under controlled conditions. From the results presented in this conference contribution, it can be deduced that the mass and speed of the robot exert a high influence on the severity of human injury in the event of a collision. In this regard, in several figures of the conference contribution by S. Haddadin et al. illustrated the injury level determined using a "Hybrid III crash test dummies" in a human-robot collision. In view of these results, large-scale and above all powerful industrial robot systems (with high payloads, high speeds and collision-risky robot parts or tools) have hitherto been prevented from being used in human-robot teams due to the inability of known security concepts for complete collision avoidance for safety reasons.

Although the standard use of airbags as restraint devices in the event of accidents in order to greatly reduce injuries in the region of the upper body or head of the vehicle occupants has long been known in the motor vehicle field (cf. DE 896 312 B . US Pat. No. 2,649,311 . DE 101 39 194 B4 ). However, the requirements placed on airbags in the field of motor vehicles deviate considerably from those to be considered in robot collaboration applications.

A motor vehicle airbag is inflated with a time delay from a certain load. Since the collision between the occupants and parts of the vehicle interior, z. B. steering wheel, takes place only a few milliseconds after the crash accident, such a delayed airbag deployment for optimum protection and avoidance of resulting from the inflation of the airbag injuries is advantageous and therefore desirable. The airbag control unit will ignite the gas generator of the airbag only about 30 milliseconds before the collision with the accelerating body part of the occupant, so that the airbag inflates completely and thus intercepts the respective body part. However, the above-described activation concept for vehicle airbags is not suitable for reducing the extent of damage of a human-robot collision in MRK applications where the respective person is directly hit by the robot in the event of a collision. In addition, in contrast to the smooth surfaces of the vehicle interior (in particular the steering wheel), the robot has a large number of extremely collision-hazardous elements (eg robot arms with points, sharp edges and shearing edges).

Finally, serve airbags in motor vehicles only to certain surfaces of the vehicle interior, such. As windshield, dashboard or steering wheel to cover in case of collision. It is assumed that the collision with the body part of the vehicle occupant takes place only in one direction, since the body part is thrown forward by the force of inertia acting on the occupants in the event of a frontal crash impact. Consequently, the main function of a motor vehicle airbag is to absorb as much as possible the inertial force that accelerates the occupants in the event of an accident, and thus to protect the respective body part from collision damage. In contrast, an industrial robot represents a fully dynamic system with very large work surfaces in all three spatial directions. An industrial robot allows effortlessly the controlled movement of a load of up to 200 kg in a working radius of up to 3 m. In the event of a collision, a person or other object located in the robot work area can therefore be struck from any direction by any part of the robot (at worst, by sharp corners and points on the robot arms or tools).

In summary, it should be noted that due to the special design and the special activation method of motor vehicle airbags known from the motor vehicle field occupant protection systems are not readily transferable to MRK applications.

The invention has the object to overcome the aforementioned disadvantages and limitations of the prior art and to provide a safety device and a safety method for the safe operation of controlled in a working area movable robot that allow in the future, the close cooperation with such a robot and to ensure the safety of an object (in particular a person) located in the robot work area, even in the event of a collision.

This object is achieved by a safety device having the features of claim 1 and a corresponding safety method having the features of claim 16.

It is a further object of the invention to provide a corresponding industrial robot capable of meeting the high safety requirements for use in MRI systems.

This object is achieved by an industrial robot having the features of patent claim 12.

Specifically, the safety device according to the present invention for safely operating a robot controllably movable in a work area comprises position detecting means for detecting the current position of at least one working area relative to the robot, braking distance calculating means for calculating the braking distance of the robot at its current moving state, a damage amount calculating means for calculating the amount of damage in the event of a robot-object collision occurring with the robot moving unchanged, stopping means for stopping the robot, triggering means for triggering at least one airbag installed in the robot, and control means arranged to activate the stopping means and the triggering means; if a distance between the robot and the object derived from the detected relative position is smaller than the calculated braking distance of the robot and the calculated amount of damage is greater it is considered a predetermined damage limit.

In parallel with the sensory detection of the relative position between the potential collision object located in the working area and the robot, the following two factors are thus calculated by the safety device according to the invention at all times and considered in the assessment of the risk of collision: 1. Braking distance of the robot; 2. The extent of damage in a potential collision.

The braking distance of the robot, d. H. The distance within which the robot would come to a halt during immediate braking depends primarily on the kinetic energy of the robot to dissipate, which in turn depends on its speeds, masses and moments of inertia, which in turn can vary depending on the moving load. Accordingly, the braking distance can be determined online during operation on the basis of a model which describes the dynamics of the robot, in particular as a function of its speed and load mass. Due to the high speeds (over 2 m / s) and the high moving load masses (up to 200 kg), industrial robots can have dangerously long braking distances depending on the situation, which must not be left unconsidered. The braking distance is part of the collision danger area and therefore forms the minimum distance that must be maintained at all times between the potential collision object and the robot. If the actual distance falls below this minimum distance, appropriate emergency measures (stopping the robot and triggering the relevant airbag) must usually be initiated immediately, in order, for B. to avoid a collision of the object against the hard housing of a robot arm.

However, it does not require every potential contact between a robot and an object in its workspace to take any collision avoidance emergency measures. In addition to falling below the specified by the braking distance minimum distance is therefore required by the safety device according to the invention as a second criterion for the activation of such emergency measures that the occurring in a potential collision extent of damage exceeds a corresponding limit. In this way, z. B. be excluded that an emergency shutdown for rapid shutdown of the robot is caused even at the slightest touch that cause neither the respective object nor the robot to relevant damage. Because of the large mass involved in such an emergency shutdown inevitably large forces that the robot should be exposed only in real emergency situations. Applied to a human-robot collision, this means that emergency measures are only activated if the collision forces acting on the person (with unchanged robot movement) would lead to pain and in particular to injuries. There are currently several studies in which the permissible limit values for the contact case between human and robot have been determined. In this case, a violation of the human must be safely excluded. First findings regarding the biomechanical limits for the contacts between humans and robots are z. B. within the technical specification ISO / TS 15066 (robots and robotic devices) processed and can be used to validate a safe MRC.

In a preferred embodiment of the safety device according to the invention, the position detection means comprises at least one 3D camera system whose viewing area completely or partially covers the working area of the robot. Such a camera system may in turn comprise an electronic image processing device, which is coupled to at least one camera for detecting the robot working area to determine the relative position of the object with respect to the robot and thus taking into account the two pre-figured factors (braking distance and potential extent of damage) Assess collision risk.

In a further embodiment of the safety device according to the invention, the position detection means comprises sensors located on the robot and / or on the object for detecting the respective current position of the robot and / or the object. The distance between the object and the robot is thus permanently monitored by the sensor system in order to shut down the robot when it falls short of the respectively required minimum distance (current braking distance) (under the further condition that a predefined damage limit is exceeded in the event of a potential collision).

More preferably, in the case of a single or multi-axis robot, the sensors are each integrated in the axle joints of the robot. In more complex robots, such as, for example, six-axis industrial robots, thus the joint coordinates, in particular joint angle, and by time derivative, the joint (angle) velocities can be determined at any time to use it (taking into account the load parameters) z. B. to calculate the current robot braking distance exactly.

In the event that the object is a person, it is further preferred for the sensors to be present at the joints and / or at further biomechanically relevant points of the person are attached. To detect body segment positions in space, a variety of so-called "markers" can be used, which are attached to biomechanically relevant positions, such as the shoulder, the hand, the hip and the heel, of the respective person. A camera system can then continuously determine the three-dimensional spatial coordinates for these "markers" over the entire measuring time, from which the distance between the robot and the person can be determined.

Furthermore, it is also preferred that at least one sensor is designed as a wireless inertial sensor, in particular as a 3D gyroscope, accelerometer and / or magnetometer. These inertial sensors consist of mass elements that perform a displacement when displaced by acceleration or negative acceleration. This change in location is detected in various ways or implemented as a signal. By integrating the accelerations and rotation rates measured by the inertial sensors, the spatial movement of the robot and, in each case, the current spatial position are continuously calculated.

Alternatively or additionally, it can be provided that at least one sensor is designed as a capacitive sensor enveloping the robot. By using such a robot cover with capacitive sensors, information about the relative position of the potential collision object is continuously available in the vicinity of the robot.

Moreover, in one embodiment of the invention, it is preferably provided that the braking distance calculating means is designed to calculate the braking distance on the basis of at least one of the following parameters: robot path, mass, speed and other mechanical deceleration factors. For example, tolerances, wear, heating and the like, which lead to different Bremskraft- or Bremsmomentverläufen and thus to different braking distances, be considered as other mechanical delay factors in the context of the invention. Also, gravity, depending on whether it induces additional braking forces and moments or counteracts these accelerating, shorten or extend the braking distance.

According to a further embodiment of the invention, the damage amount calculating means is designed to calculate the extent of damage as a function of the robot part striking the object in the event of a collision, in particular depending on its shape, material, size, mass and / or speed. In addition to mass and speed, the appearance or the property of the colliding robot part, in particular the size, shape and sharp edge, is of essential importance for the potential extent of damage (injury severity) at the collision object (person).

In yet another embodiment of the invention, it is provided that the damage extent calculation means is designed to calculate the extent of damage as a function of the object part struck by the robot in the event of a collision, in particular as a function of its sensitivity to collisions. For this purpose, the damage-extent-calculating means can, for example, be a database with empirically determined data on impairments of a person (eg no impairment, pain sensation, bruising without injury to the skin, slight superficial skin injury, moderate skin injury, etc.) in the event of a robot part colliding with a specific one Body part (eg head, neck, rib cage) included.

Another aspect of the invention is finally an industrial robot with at least one airbag, which is housed in the deactivated folded state in a housing of the robot and exiting the activated state of the housing of the robot in the activated. For the first time, the use of an airbag integrated in the robot housing is thus proposed for an industrial robot, which inflates in the event of a possible collision with a collision object (in particular a person) and thus reduces the severity of the collision and the resulting collision damage.

Further features of the invention will become apparent from the following description and from the drawings, in which the safety device according to the invention and the security method according to the invention are shown using the example of a human-robot interaction. Show it:

1 schematic representation for determining the relative position between a person and an industrial robot by means of a 3D camera system and sensors,

2 schematic representation of a robot according to the invention with an enlarged detail view of the housed in the robot housing airbags,

3 to 5 Time sequence of a robot movement with an initialized by a safety device according to the invention airbag deployment to avoid a human-robot collision.

Safety device and method according to the invention can be used successfully in particular in human-robot cooperation (MRC). For MRK applications is located in Correspondence to 1 a person 6 in the working area of a robot 1 , The robot 1 In this case, it is moved in the work area along a programmed trajectory at a programmed speed. A mobile platform 15 of the robot 1 is on a base frame 16 mounted so that it can rotate about its central axis. A first lower robot arm 14a is a first horizontal pivot 9a swiveling on the platform 15 stored. A second upper robot arm 14b is pivotable with its one end turn on the first lower robot arm 14a by means of a second horizontal axle joint 9b hinged and has at its other end a robot tool in the form of a gripper 13 with two fingers, with the gripper 13 also pivotable via a third horizontal pivot 9c on the second robot arm 14b is articulated.

The robot 1 is for any cooperation task with a person 6 used. Such cooperation can be found, for example, in chained assembly lines, where necessary multiple cycles between automatic stations and manual workstations are necessary. So can, for example, after the one by one person 6 To be performed manual operations are completed, the workpiece of the with the second robot arm 14b connected schematically illustrated gripper 13 and transferred to a subsequent automatic or manual processing station. Here are the robot arms 14a . 14b , the grapple 13 and that of the grapple 13 held workpiece in the three-dimensional workspace moves, so the risk of collision between the robot 1 or the workpiece and the person staying in the work area 6 (Worker) exists.

So far, only lightweight robots seemed to meet the stringent safety requirements for use in human-robot cooperation (MRC). However, in order to enable classic industrial robots to be used in collaborative operation, the invention provides a corresponding safety device and a corresponding safety method that take into account the high speeds and load capacities present in such industrial robots.

For industrial robots to be able to work together with humans, the robot must first be reliably monitored 1 and the robot environment in real time. 1 shows the sensors used in an MRK application for determining the relative position between a person located in the robot workspace 6 and the robot 1 , A complete three-dimensional monitoring of the robot working area is provided by a 3D camera system 2 which is mounted vertically above the robot work area to be monitored and with its field of view completely covers the robot work area.

In addition to the pre-defined 3D camera system 2 have robots 1 and person 6 additionally via additional sensors 3 . 4 . 5 to continuously determine their position and position in space as well as their movements within the space. Preferably, this wireless wireless inertial sensors 3 . 5 (eg 3D gyroscopes, accelerometers, magnetometers) at the axle joints 9a . 9b . 9c of the robot 1 as well as at the joints and other biomechanically relevant places of the respective person 6 appropriate. Such inertial sensors 3 . 5 are commercially available as integrated components, the dimensions of which are only a few millimeters or centimeters. Suitable acceleration sensors are already used, for example, in motor vehicles in order to trigger an airbag on the basis of the detected accelerations which occur, for example, in the event of an accident. In these cases, however, the detected acceleration itself serves as a measured quantity, whereas the present invention determines a movement path and a movement speed on the basis of the detected acceleration. As an additional sensor is according to 1 a the robot 1 enveloping capacitive sensor 4 provided, which serves the close range of the robot 1 continuously monitor and the relative position of a collision object (Person 6 ) to investigate.

It is already known to provide touch-sensitive sleeves on robots in order to realize an emergency shutdown at a certain safety distance when touched. However, a tactile safety sensor alone is not sufficient to allow safe cooperation of humans and robots in close proximity to each other. In particular, such a tactile safety sensor is not suitable to be used in industrial robots as the sole means of security, since the fundamental problem is that an imminent collision must be detected early. Because of their high inertia, industrial robots will always come to a standstill only with a certain delay.

Therefore, in the safety device according to the invention, use is made of a braking distance calculating means which corresponds to the respective current state of motion of the robot 1 associated braking distance calculated. This calculation of the braking distance is at least taking into account the robot path, the robot mass and the robot speed. Robot track and robot speed can be out of those at the axle joints 9a . 9b . 9c from the sensors 3 recorded joint (angle) positions and joint (angle) speeds are determined. Masses and dimensions of the individual mobile robot parts are stored in a database which can be selectively accessed by the braking distance calculating means.

The calculated braking distance is according to the invention as a safety-technically permissible minimum distance between the robot 1 and the potential collision object (eg person 6 ). Based on the thus calculated braking distance and on the basis of the position detection according to 1 determined actual distance d of the robot 1 to the collision object (eg person 6 ) determines whether this distance d can still be achieved for a sufficient damage reduction by braking. If the current braking distance exceeds the detected distance d between robots 1 and potential collision object 6 , can cause an immediate shutdown (emergency stop) of the robot 1 initiated in order to avoid a collision or to reduce its consequences. In addition, it can be provided that a speed reduction of the robot already takes place when the robot-human distance d approaches the calculated braking distance 1 is made to the braking distance in a subsequent shutdown of the robot 1 continue to reduce and thus avoid a collision anticipatory.

However, the inventor has realized that not everyone has such a trivial contact between robots 1 and collision object (eg person 6 ) triggering an immediate emergency stop of the robot 1 required. A safety-related emergency stop loads the supporting structure of the robot due to the pulse-like forces generated in the process 1 and sometimes leads to significant production disruptions, in addition to the loss of time due to the restart of the robot 1 After the emergency stop, the workpiece is unusable or at least must be reworked. Therefore, an emergency stop should only be initiated if the potential extent of damage prevented by such an emergency stop exceeds an intolerable extent.

With the safety device and the safety method according to the invention is therefore made possible in the movement of the robot 1 the hazard potential of objects detected as obstacles in the trajectory 6 to weight. According to the invention, such a weighting is achieved in that resulting from the sensory monitoring of the robot 1 and the robot work area resulting movement sequence of the robot 1 and the person 6 not only for calculating the braking distance, but also for calculating the amount of damage occurring in a potential collision. The emergency shutdown of the robot 1 is activated (even if the human-robot distance d is less than the braking distance) only when the calculated amount of damage is greater than a certain limit. This concept allows a person 6 with a robot 1 working together, because on the one hand, the safety of the person 6 guaranteed at any time and on the other hand in trivial (possibly also wanted) contacts an unnecessary shutdown of the robot 1 is avoided.

The calculation of the extent of damage is in the case of 1 to 5 represented human-robot interaction synonymous with the calculation of the occurring in a potential collision injury level (English level) of the person involved 6 , The severity of the injury depends on the person's body part 6 from. For example, a collision with the upper arm is considered to be less critical than a collision with sensitive parts of the body, such as the head 11 or the neck. In a database, characteristic data on typical body sub-forms are preferably stored. These characteristic data support the sensors in the mechanical classification of the detected body parts and thus in the machine detection of body parts, eg. B. with means of optical pattern recognition (as the in 1 shown 3D camera system 2 ).

On the other hand, the severity of injury depends crucially on the colliding robot part 10 , in particular of its mass and speed, from. A heavy, high-speed robot part understandably causes more damage than a lightweight, low-speed robot part. The current speed of the colliding robot part 10 can from the results of the in the axle joints 9a . 9b . 9c integrated inertial sensors 3 be derived. In the estimated collision speed, not only the speed of the robot may be preferable 1 but also the speed of the person 6 go down, so the emergency systems of the robot 1 even when it is at rest. This allows people 6 even against an accidental collision with a standing robot 1 be secured. Dimensions and dimensions of the colliding robot part 10 can either also be detected by sensors and / or be taken from a database in which these sizes for all kinematically relevant parts of the robot 1 to provide. Also the other properties of the colliding robot part 10 , in particular its surface shape (flat or sharp-edged), may also be deposited in a database, these properties (eg typical surface shapes) in the database having different weighting factors are weighted in terms of the damage caused by them.

It is questionable when the extent of damage caused by such a potential collision is tolerable or not. For this purpose, according to the invention, the calculated potential extent of damage is compared with a predetermined damage limit value. The medical-biomechanical assessment of human-robot collisions has become increasingly the subject of research in the recent past. For example, in the BG / BGIA recommendations for the risk assessment according to the Machinery Directive (published by the BGIA Institute for Occupational Safety and Health of the German Social Accident Insurance, October 2009 edition, February 2011 version ) Assessments of collision risks between humans and robots so that risks of injury remain within tolerable limits. Within these recommendations for individual parts of the body are given information on just acceptable clamping and crushing forces, impact forces, pressure and surface pressure, which can be stored in a database to be read by the safety device depending on the situation as damage limits. In this connection can also of the in the Robot safety standard ISO / TS 15066 published limits. In the case of a human-robot collision, the damage threshold may generally be a pain threshold of the respective body part, accepting damage caused below that pain threshold, and only considering damage exceeding the pain threshold.

Despite the immediately initiated stopping of the robot 1 It may be due to delay and inertia nor to a collision with rigid and possibly sharp-edged parts of the robot 1 come, leading to serious injury to the person involved 6 can lead. In order to cover collision-risky robot parts (in particular points, sharp edges and shearing edges) and to reduce the consequences of a collision or even avert it altogether, the stopping of the robot caused by the stopping means takes place at the same time 1 a triggered by a triggering means triggering at least one in the robot 1 built-in airbags 7 . 8th ,

At the in 2 shown detail is the internal structure of the robot 1 in the bordered by an ellipse end portion of the second upper robot arm 14b shown which according to 4 and 5 with one person 6 in collision contact device. How farther 2 can be seen on two opposite sides of a longitudinal axis L of the robot arm 14b two empty folded airbags 7 . 8th in one of covers 12a . 12b formed housing 12 of the robot 1 accommodated. To the airbags 7 . 8th in the non-inflated state to keep in a position in which they fit as closely as possible to the robot structure, so that any impairment of the freedom of movement of the robot 1 is prevented, corresponding holding devices (eg straps) may be provided. Every airbag 7 . 8th surrounds a cavity, which is respectively connected to a fluid supply, wherein the supply of the fluid z. B. can be done by a compressed air system or by a (pyrotechnic ignited) gas cartridge or by a chemical reaction. Due to the pressure buildup occurring sudden deployment of the airbag 7 . 8th becomes the respective cover 12a . 12b of the robot housing 12 exposed to a high outward force. As a result of this from the airbag 7 . 8th applied force is in the respective cover 12a . 12b an opening is released through which the deploying airbag 7 . 8th can pass through. For example, the release of an opening by a hinge-like connection of the respective cover 12a . 12b with the rest of the robot housing 12 be achieved.

In 3 to 5 is shown how the positions of the robot 1 as well as the person in the robot workspace 6 to change over time. One with unchanged movement of the robot 1 with the head 11 the person 6 colliding robot part 10 (consisting of the second robot arm 14b and the gripper attached thereto 13 ) turns clockwise around the second knuckle joint 9b turned. Because the acceleration of this rotating robot part 10 from the beginning of the labor movement onwards, or at least at regular intervals with those in 1 shown inertial sensors 3 in the axle joints 9a . 9b . 9c can be determined mathematically, its current speed and its current position. As long as the rotating robot part 10 on the remaining distance d between robot part 10 and person 6 safely come to a halt, there is no reason to stop the robot 1 initiate. Only when the calculated braking distance exceeds the present distance d and when the calculated extent of damage exceeds a limit, which in the present case z. B. with a pain threshold or injury threshold of the human head 11 matches, the robot becomes 1 stopped and at the same time a colliding robot part 10 integrated airbag 7 according to 5 inflated to the human head 11 before a collision with the hard robot housing 12 to protect. In contrast to the triggering method in a motor vehicle airbag recognizes according to 1 Sensor used for position detection the danger of a human-robot collision already from the outset before the actual impact and activated in advance the respective robot airbag 7 ,

According to 2 . 4 and 5 are in the gripper end of the second upper robot arm 14b two airbags 7 . 8th on two different sides of the robot arm longitudinal axis L in the robot housing 12 added. In the event of a collision, only the airbag that is on the collision object will always be affected 6 facing side, in the present case so the airbag 7 on the bottom of the robot arm 14b , unfolded to protect this page protectively. On the other hand, the other remains on the collision object 6 remote side airbag, in the present case, therefore, the upper airbag 8th , in the folded state and can therefore be used easily. Although in 2 . 4 and 5 the illustrated robotic airbags 7 . 8th on the end of the second upper robot arm 14b limited, it is understood that along the entire robot 1 in the robot housing 12 so many airbags are housed, that in the deployed deployed state of these airbags all a potential collision object 6 hazardous parts, such as corners, edges and / or surfaces, of the robot 1 possibly including one from the robot 1 guided tool 13 and / or workpiece are covered protectively.

Although in 1 to 5 the use of the safety device according to the invention in human-robot environments is illustrated, it can also be used advantageously in any other application cases of industrial robots in order to avoid the damage of a robot resulting from an impact accident 1 as well as the respective collision object 6 to reduce or eliminate altogether. However, MRK applications are particularly preferred applications because the human here is exposed to a very high risk and thus there is also a strong need for a safety device of the type proposed hereby.

Safety device and method according to the invention allow, depending on the colliding robot parts 10 and object parts 11 the appropriate emergency measures (immediate robot shutdown and deployment of the relevant robotic airbags 7 . 8th ) to activate. In particular, in MRK applications, such activation only takes place when the damage assessment has revealed that the collision poses a threat of massive damage to the robot 1 and / or a risk of injury to the person 6 emanates. Thus, a safe human-robot interaction is achieved, taking into account the human injury biomechanics. As a result, the robot 1 Therefore, only biomechanically generated safe movements that cause no damage even in a collision, since the present invention in the robot housing 12 integrated airbags 7 . 8th Prevent any negative impact on human security in any case. In principle, work that has long since been stopped in Germany due to excessive manual labor costs can again be economically realized in human-robot collaboration.

LIST OF REFERENCE NUMBERS

1

robot

2

3D camera system (position detection means)

3

Sensors in robot axle joints (position detection means)

4

robotic capacitive sensor (position detecting means)

5

Sensors on object (position detection means)

6

Person (object, collision object)

7, 8

airbags

9a, 9b, 9c

Axis joints of the robot

10

Robot object meeting (colliding) object

11

human head (robot-hit object)

12

Housing of the robot

12a, 12b

Covers of the robot housing

13

Gripper (tool)

14a, 14b

robot arms

15

Platform of the robot

16

Basic frame of the robot

d

Distance between robot and object

L

Longitudinal axis of the robot arm

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 896312 B [0008]
• US 2649311 A [0008]
• DE 10139194 B4 [0008]

Cited non-patent literature

• Conference Paper "Safety Evaluation of Physical Human-Robot Interaction via Crash-Testing" by S. Haddadin et al., Published in Proceedings of the Robotics Science and Systems Conference (RSS), Atlanta, GA, USA, Jun. 2007, pp. 217-224 [0007]
• ISO / TS 15066 (robots and robotic devices - collaborative robots) [0019]
• BGIA Institute for Occupational Safety and Health of the German Social Accident Insurance, October 2009 edition, February 2011 version [0046]
• Robot safety standard ISO / TS 15066 [0046]

Claims (16)

Safety device for safe operation of a robot which can be moved in a controlled manner in a working area ( 1 ), comprising: - position detecting means ( 2 . 3 . 4 . 5 ) for detecting the current position of at least one object located in the working area ( 6 ) relative to the robot ( 1 ), Braking distance calculation means for calculating the braking distance of the robot ( 1 ) at its current state of motion, - a damage amount calculating means for calculating the amount of damage in the case of a movement of the robot unchanged ( 1 ) collision between robots ( 1 ) and object ( 6 ), - a stopping means for stopping the robot ( 1 ) and a triggering means for triggering at least one in the robot ( 1 ) built-in airbags ( 7 . 8th ) and - a control means which is designed to activate the stopping means and the triggering means when - a distance (d) between robots (d) derived from the detected relative position 1 ) and object ( 6 ) smaller than the calculated braking distance of the robot ( 1 ) and - the calculated amount of damage is greater than a specified damage limit. Safety device according to claim 1, wherein the position detection means comprise at least one 3D camera system ( 2 ) whose viewing area covers the working area of the robot ( 1 ) completely or partially covers. Safety device according to claim 1 or 2, wherein the position detection means on the robot ( 1 ) and / or on the object ( 6 ) located sensors ( 3 . 4 . 5 ) for detecting the current position of the robot ( 1 ) and / or the object ( 6 ). Safety device according to claim 3, wherein in the case of a single or multi-axis robot ( 1 ) the sensors ( 3 ) each in the axle joints ( 9a . 9b . 9c ) of the robot ( 1 ) are integrated. Safety device according to claim 3 or 4, wherein in the event that the object ( 6 ) is a person who uses sensors ( 5 ) are attached to the joints and / or other biomechanically relevant sites of the person. Safety device according to at least one of the preceding claims 3 to 5, wherein at least one sensor ( 3 . 5 ) is designed as a wireless inertia sensor, in particular as a 3D gyroscope, accelerometer and / or magnetometer. Safety device according to at least one of the preceding claims 3 to 6, wherein at least one sensor ( 4 ) as a the robot ( 1 ) enveloping capacitive sensor is formed.  Safety device according to at least one of the preceding claims 1 to 7, wherein the braking distance calculating means is adapted to calculate the braking distance based on at least one of the following parameters: robot track, mass, speed and other mechanical deceleration factors. Safety device according to at least one of the preceding claims 1 to 8, wherein the damage amount calculating means is designed to determine the extent of damage as a function of the case of collision on the object ( 6 ) meeting robot part ( 10 ), in particular depending on its shape, material, size, mass and / or speed. Safety device according to at least one of the preceding claims 1 to 9, wherein the damage amount calculating means is designed to determine the extent of damage as a function of the case of collision of the robot ( 1 ) hit object part ( 11 ), in particular as a function of its sensitivity to collisions. Safety device according to at least one of the preceding claims 1 to 10, wherein in the event that the object ( 6 ), the calculated amount of damage is a measure of the severity of the collision with the robot ( 1 ) is a bodily injury. Industrial robot with at least one airbag ( 7 . 8th ), which in the deactivated collapsed state in a housing ( 12 ) of the robot ( 1 ) is housed and in the activated unfolded state from the housing ( 12 ) of the robot ( 1 ) exit. An industrial robot according to claim 12, wherein the airbag ( 7 . 8th ) receiving housings ( 12 ) at least one cover ( 12a . 12b ) due to activation of the airbag ( 7 . 8th ) of the unfolding airbag ( 7 . 8th ) exerts an opening through which the deploying airbag ( 7 . 8th ) can pass through. An industrial robot according to claim 12 or 13, wherein the robot ( 1 ) with several airbags ( 7 . 8th ), which in the activated unfolded state all have a collision object ( 6 ) hazardous parts, such as corners, edges and / or surfaces of the robot ( 1 ) and / or one from the robot ( 1 ) held tool ( 13 ) and / or workpiece cover. An industrial robot according to at least one of the preceding claims 11 to 14, wherein the robot ( 1 ) at least one robot arm ( 14 ) and at least two airbags ( 7 . 8th ) are arranged on two different sides of a robot arm longitudinal axis (L) in order, in the event of a collision, on a collision object ( 6 ) apt side of the robot arm ( 14a . 14b . 14c ) by the deployed airbag ( 7 . 8th ) cover. Safety method for the safe operation of a robot that can be controlled in a working area ( 1 ), preferably using a safety device according to at least one of the preceding claims 1 to 11 and / or a robot ( 1 ) according to at least one of the preceding claims 12 to 15, comprising the steps: - detecting the current position of at least one object located in the working area ( 6 ) relative to the robot ( 1 ), - calculating the braking distance of the robot ( 1 ) at its current state of motion, - calculating the extent of damage in the case of an unchanged movement of the robot ( 1 ) collision between robots ( 1 ) and object ( 6 ), - stopping the robot ( 1 ) and triggering at least one in the robot ( 1 ) built-in airbags ( 7 . 8th ), if - a distance (d) between robots (12) derived from the detected relative position 1 ) and object ( 6 ) smaller than the calculated braking distance of the robot ( 1 ) and - the calculated amount of damage is greater than a specified damage limit.

Images