Modeling a robot working environment

1 . A method for modeling a working environment of a robot comprising the steps of:

a) providing a robot comprising a base, a reference point, a plurality of links by which the reference point is movably connected to the base, and sensors for detecting positions of or angles between the links,

b) providing a controller for the robot, the controller being adapted to associate a position of the reference point to detected positions or angles between of the links,

c) installing the base in a working environment which is delimited by at least one surface,

d) moving the reference point to at least one sample point of the at least one surface, wherein the controller supports an exploration mode of the robot, in which step d) is carried out by the controller controlling displacement of the reference point along a path,

e) determining the position of the sample point from positions of or angles between the links detected while the reference point is at the sample point, wherein the reference point is contact sensitive, wherein step e) is triggered by the reference point sensing contact with the surface, wherein the robot comprises an end effector which has a pin, wherein a first pressure sensor is located between a proximal end of the pin and a bottom of a socket to detect the pin pressing against an obstacle in its axial direction, wherein second pressure sensors are arranged circumferentially around the pin to detect a radial force acting on the pin and a direction of the radical force, wherein the controller evaluates signals from the sensors to detect contact of the pin with the at least one sample point and to estimate a direction of a surface normal at the at least one sample point, and

f) inferring the position of the surface from the determined position, wherein the controller extrapolates where the surface will extend in a vicinity of the at least one sample point from the estimated direction of the surface normal at the at least one sample point.

2 . The method of claim 1 , further comprising step g) selecting a geometric type of the at least one surface among a plurality of predefined types, wherein each of the predefined types has a predetermined sample number n associated to it, and wherein step f) is carried out after steps d) and e) have been carried out at least n times.

3 . The method of claim 2 , wherein the plurality of geometric types comprises one or more of a horizontal plane, a vertical plane, an arbitrarily oriented plane, a sphere, an ellipsoid, a cylinder, a cone.

4 . The method of claim 1 , wherein step f) comprises fitting the surface to the determined positions, and assessing a quality of the fit.

5 . The method of claim 1 , wherein the working environment is delimited by a plurality of surfaces, further comprising the step of h) determining, for at least two of the surfaces, at least one line in which the surfaces intersect, and assuming the line as a border of the surfaces.

6 . A controller for a robot comprising a base, a reference point, a plurality of links by which the reference point is movably connected to the base, and sensors for detecting positions of or angles between the links, the controller being adapted to:

receive positions of or angles between the links detected by the sensors,

associate a position of the reference point to the detected positions, and, when the reference point is located at a sample point of a surface delimiting a working environment of the robot, to determine the position of the sample point from positions of or angles between the links detected while the reference point is at the sample point, wherein the reference point is contact sensitive, wherein determination of the position of the sample point is triggered by the reference point sensing contact with the surface, wherein the robot comprises an end effector which has a pin, wherein a first pressure sensor is located between a proximal end of the pin and a bottom of a socket to detect the pin pressing against an obstacle in its axial direction, wherein second pressure sensors are arranged circumferentially around the pin to detect a radial force acting on the pin and a direction of the radical force, wherein the controller is configured to evaluate signals from the sensors to detect contact of the pin with the sample point and to estimate a direction of a surface normal at the sample point, and

infer the position of the surface from the determined position, wherein the controller extrapolates where the surface will extend in a vicinity of the sample point from the estimated direction of the surface normal at the sample point.

7 . The controller of claim 6 , further comprising a user interface enabling a user to select a geometric type of the surface among a plurality of predefined types.

8 . A robotic system comprising:

a robot comprising a base, a reference point, a plurality of links by which the reference point is movably connected to the base, and sensors for detecting positions of or angles between the links, and

a controller associated with the robot, the controller being adapted to:

receive positions of or angles between the links detected by the sensors,

associate a position of the reference point to the detected positions, and, when the reference point is located at a sample point of a surface delimiting a working environment of the robot, to determine the position of the sample point from positions of or angles between the links detected while the reference point is at the sample point, wherein the reference point is contact sensitive, wherein determination of the position of the sample point is triggered by the reference point sensing contact with the surface, wherein the robot comprises an end effector which has a pin, wherein a first pressure sensor is located between a proximal end of the pin and a bottom of a socket to detect the pin pressing against an obstacle in its axial direction, wherein second pressure sensors are arranged circumferentially around the pin to detect a radial force acting on the pin and a direction of the radical force, wherein the controller is configured to evaluate signals from the sensors to detect contact of the pin with the sample point and to estimate a direction of a surface normal at the sample point, and

infer the position of the surface from the determined position, wherein the controller extrapolates where the surface will extend in a vicinity of the sample point from the estimated direction of the surface normal at the sample point.