Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
  • B25J9/00—Programme-controlled manipulators
  • B25J9/16—Programme controls
  • B25J9/1628—Programme controls characterised by the control loop
  • B25J9/1633—Programme controls characterised by the control loop compliant, force, torque control, e.g. combined with position control
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
  • B25J13/00—Controls for manipulators
  • B25J13/08—Controls for manipulators by means of sensing devices, e.g. viewing or touching devices
  • B25J13/085—Force or torque sensors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
  • B25J19/00—Accessories fitted to manipulators, e.g. for monitoring, for viewing; Safety devices combined with or specially adapted for use in connection with manipulators
  • B25J19/0004—Braking devices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
  • B25J9/00—Programme-controlled manipulators
  • B25J9/16—Programme controls
  • B25J9/1602—Programme controls characterised by the control system, structure, architecture
  • B25J9/1605—Simulation of manipulator lay-out, design, modelling of manipulator
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
  • B25J9/00—Programme-controlled manipulators
  • B25J9/16—Programme controls
  • B25J9/1628—Programme controls characterised by the control loop
  • B25J9/1651—Programme controls characterised by the control loop acceleration, rate control
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
  • B25J9/00—Programme-controlled manipulators
  • B25J9/16—Programme controls
  • B25J9/1674—Programme controls characterised by safety, monitoring, diagnostic
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
  • B25J9/00—Programme-controlled manipulators
  • B25J9/16—Programme controls
  • B25J9/1602—Programme controls characterised by the control system, structure, architecture
• • G—PHYSICS
  • G05—CONTROLLING; REGULATING
  • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
  • G05B2219/00—Program-control systems
  • G05B2219/30—Nc systems
  • G05B2219/39—Robotics, robotics to robotics hand
  • G05B2219/39319—Force control, force as reference, active compliance
• • G—PHYSICS
  • G05—CONTROLLING; REGULATING
  • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
  • G05B2219/00—Program-control systems
  • G05B2219/30—Nc systems
  • G05B2219/40—Robotics, robotics mapping to robotics vision
  • G05B2219/40541—Identification of contact formation, state from several force measurements

Definitions

• the present invention relates to a method and a controller for controlling a robot as well as an arrangement with a robot and the controller and to a computer program product for carrying out the method.
• the robot can in particular also work in unknown or varying surroundings, for example workpieces whose positions vary, approach and stop on contacting, for example in order to grasp, machine or the like.
• the robot is still running, so that it stops after detecting the impressed or reached desired force only with a certain delay.
• the object of the present invention is to improve the operation of a robot. This object is achieved by a method having the features of claim 1.
• Claims 13-15 protect a controller and a computer program product for carrying out a method and / or an arrangement with a robot and a controller described here.
• the subclaims relate to advantageous developments.
• a method of controlling a robot comprises the steps of:
• the robot decelerates in dependence on the contact rigidity predetermined in advance and / or during the contacting and / or takes it into account during deceleration and thereby or even begins the deceleration before reaching the desired force and thus an overrun of the robot with a corresponding
• Reduced power over the target force and preferably, at least substantially avoided, in one embodiment, the conformity of the reaction force, which finally impresses the stopped or stopped robot actually on the contact point, can be improved with the predetermined desired force and / or the robot also near the contact point even higher
• the robot has at least three, in particular at least six, in particular at least seven, (motion) axes or joints, which are controlled, decelerated, in particular can be stopped or braked by the drives and / or brakes of the robot. in particular, shut down, can (can).
• motion in particular
• can can
• rules based on a (rule) difference between the setpoint and (detected) actual variables are referred to as taxes in the sense of the present invention.
• a force in the sense of the present invention can generally also include an antiparallel force pair, ie a (rotational) moment, in particular.
• stiffness is understood in particular in the usual way as a ratio between a penetration depth or, in particular, elastic and / or plastic deformation and a force required or impressed thereon, in particular a quotient of force through penetration depth or deformation.
• the sustained or suspended robot imprints the reaction resp. Target force by a robot-guided tool or piece on the contact point or is provided or set up for this purpose.
• the braking of the moving robot by means of its drives and / or brakes for imparting the desired force comprises a corresponding (on) control, in particular therefore rules, of the drives or brakes, in particular determination and / or command of a desired Pose of the persistent or
• the moving robot is stopped by its drives and / or brakes for impressing the desired force in a first pose or brought to a halt, if the contact stiffness has a first value or is determined accordingly, and stopped in a second pose, in which he, in particular the robot-controlled tool or piece, penetrated deeper into the contact point or a greater deformation is achieved if the contact stiffness has a second value or is determined accordingly or is the smaller as the first value.
• the deceleration by the drives and / or brakes for impressing the desired force is started at a first time before the target force is reached, if the contact stiffness has a first value or is determined accordingly, and is started at a later second time before the target force is reached, if the contact stiffness has a second value or is determined accordingly, which is smaller than the first value, in particular the deceleration initiated by the drives and / or brakes at the first time, in particular commanded, if the contact stiffness has the first value, and initiated or commanded to the second time, if the contact stiffness has the second value.
• the robot is slowed down or delayed by its drives and / or brakes for impressing the desired force in at least one phase, if the contact stiffness has a or the first value or is determined accordingly , and slowed down or delayed at least in this phase, if the contact stiffness has a second value or is correspondingly determined, which is smaller than the first value.
• the method comprises the step of detecting a current or forthcoming contacting of the contact point by the moving robot, in particular a beginning or closing a contact between robot and contact point, wherein the moving robot by its drives and / or brakes for Imposing the target force on the contact point is slowed down by the sustained or stopped robot on the basis of or in dependence (also) on this detected contact.
• Reaction force which the robot imprints on the contact point depends on the one hand on the contact stiffness and on the other hand on the penetration depth or, in particular elastic and / or plastic, deformation, which in turn from the difference of the pose of the robot to his pose when contacting of the
• Position of the robot contact area x and its position x c when contacting is achieved. Accordingly, in one embodiment by braking the moving Robot, in particular stopping in the first or second pose, Begin (braking) at the first or second time and / or stronger or weaker braking, depending on the detected contact a tracking of the robot with a corresponding increase in force reduced and preferably, at least In essence, avoided, and thus the match of the reaction force, which finally impresses the sustained or stopped robot actually on the contact point, improved with the predetermined target force and / or the robot even in the vicinity of the contact point even higher
• Moved speed and so in particular a cycle time can be reduced.
• the braking of the moving robot by its drives and / or braking for impressing the target force on the contact point by the sustained or stopped robot may already be started even before the moving robot contacts the contact point for this purpose. This makes it possible in one embodiment, even at high contact stiffness and / or high approach speeds to avoid too deep penetration of the robot with a correspondingly large force over the target force addition.
• the deceleration of the moving robot by its drives and / or braking for impressing the target force on the contact point by the sustained or stopped robot may not be started until after the moving robot already contacted the contact point. This makes it possible in one embodiment, by detecting a reaction force between the contact point and the robot contacting them to detect the current contact based on this reaction force and / or the
• one or the reaction force between the contact point and the robot contacting them is detected and the current contact detected on the basis of this reaction force, in particular a current contact detects when the reaction force exceeds a predetermined threshold or this is detected.
• the actual contacting in one embodiment can be detected precisely and / or by means of corresponding force sensors of the robot.
• a distance between the robot and the contact point is detected, in particular by means of at least one
• Braking should be started especially early.
• a desired desired force can be impressed on the contact point by the robot.
• the method comprises the step of: detecting a current movement, in particular speed and / or acceleration, of the robot, wherein the moving robot by its drives and / or brakes for impressing the target force on the contact point by the sustained or ,
• contact point and depends on the contact stiffness, advantageously precise (r) done, in particular model-based pilot-controlled and / or regulated, wherein in an embodiment in the model, the contact stiffness is considered or is.
• the moving robot is braked more strongly by its drives and / or brakes for impressing the desired force in at least one phase and / or with the deceleration by the drives and / or
• the contact stiffness is determined as a function of a rigidity of the contact point and / or a rigidity of the robot, that is to say, in one embodiment, the flexibility, in particular elasticity, of the overall system of contact point and robot is taken into account.
• the contact stiffness is determined independently of a stiffness of the contact point or independently of a rigidity of the robot, this can simplify its determination in one embodiment.
• the contact stiffness can be determined theoretically, in particular numerically, in particular by simulation, in particular estimated, in particular based on or as a function of known material and / or geometry parameters of contact point and / or robot.
• the contact stiffness can be determined empirically in one embodiment, in particular by a reaction force between the
• a reaction force between contact point or environment and robot is detected in an embodiment by a force sensor of the robot, in particular one or more
• Tool flange which, as explained above, forces may also include moments, force sensors in the sense of the present invention thus in particular torque sensors.
• the contact stiffness in one embodiment can advantageously be determined precisely (r) and / or online.
• the reaction force is detected and the contact stiffness is determined based on this reaction force while the robot is already contacting the contact point for impressing the desired force by the sustained robot contacted.
• the contact stiffness for the current contact point can be determined precisely (r).
• the robot first contacts the contact point and / or its surroundings one or more times as a test. It is (each) the
• reaction force Detects reaction force and determines the contact stiffness based on this reaction force or reaction forces, in particular by averaging, interpolation and / or extrapolation or the like, before the robot then (re) contacts the contact point for impressing the target force by the sustained or stopped robot ,
• the contact stiffness can be determined in advance in one embodiment and, in particular with high contact stiffnesses and high approach speeds, too deep penetration of the robot with a correspondingly large force increase beyond the desired force can be avoided.
• the contact stiffness is determined depending on a pose of the robot, in particular one of a plurality of pose-specific
• the rigidity of the robot and, on the other hand, the contact point and thus its stiffness may depend on the pose of the robot.
• controller for controlling the robot, in particular hardware and / or software, in particular
• the controller or its means comprises:
• a means in the sense of the present invention may be designed in terms of hardware and / or software, in particular a data or signal-connected, preferably digital, processing, in particular microprocessor unit (CPU) and / or a memory and / or bus system or multiple programs or program modules.
• the CPU may be configured to execute instructions implemented as a program stored in a memory system, to capture input signals from a data bus, and / or
• a storage system may comprise one or more, in particular different, storage media, in particular optical, magnetic, solid state and / or other non-volatile media.
• the program may be such that it is capable of embodying or executing the methods described herein, so that the CPU may perform the steps of such methods, and thus, in particular, control the robot.
• one or more, in particular all, steps of the method are completely or partially automated, in particular by the controller or its (e) means.
• Fig. 1 an arrangement with a robot and a controller for controlling the robot according to an embodiment of the present invention
• FIG. 2 shows an imprint of a reaction or desired force by the robot
• FIG. and 3 shows a method for controlling the robot according to an embodiment of the present invention.
• Fig. 1 shows an arrangement with a robot 1 and a controller 3 for controlling the robot 1 according to an embodiment of the present invention
• Fig. 3 a shows an arrangement with a robot 1 and a controller 3 for controlling the robot 1 according to an embodiment of the present invention
• a desired force F s is predetermined, which the robot is to impose on a contact point 2.
• This can be predefined by a user input, a work program or process of the robot or the like, for example.
• a desired force may be predetermined by a stop condition in a work program.
• a contact rigidity c at the pad 2 is determined depending on a rigidity of the pad 2 and a rigidity of the pad
• Robot 1 determines, which is indicated in Fig. 1 by a spring stiffness Ci of the robot 1 and a spring stiffness c 2 of the contact point 2 and in
• Contact stiffness is selected or interpolated or extrapolated between multiple contact stiffnesses.
• an average contact stiffness (c + c ') / 2 can be determined uniformly for the contact points 2, 2'. It is understood that the two contact points 2, 2 'serve merely to simplify the explanation.
• the determination of the contact stiffness c can also be made online, while the robot 1 approaches the contact point 2 in order to already impose the desired force F s , in particular at the beginning of a penetration by comparing the penetration depth and the reaction force detected in this case.
• a current or imminent contacting x c of the contact point 2 is detected by the moving robot 1.
• Variation can also be spaced from the robot 1, detects a distance between the robot 1 and the contact point 2 and the current or upcoming contact x c are detected on the basis of this distance.
• step S10 Based on the parameters specified in step S10, target force F s, the time determined in step S20 contact stiffness c and the detected in step S30, contacting x c, in a step S40, a desired pose x s is determined, the controller 3 of the robot 1 in this imposes the desired force F s .
• This is illustrated in simplified form in FIG. 2 on the basis of a linearly assumed or approximated model. It can be seen that the target pose x s in
• Embodiment by x s - -x c yields.
• step S50 the controller 3 brakes the moving robot 1 whose drives 5 so that it stops in the target pose x s and in this
• This can in particular be model-based taking into account the contact stiffness c and detection of the movement dx / dt, d 2 x / dt 2 of the robot 1. If we project simplified masses and driving forces of the robot to a mass m and a driving force F x in the direction of the drawn in Fig. 1 x-axis direction, gives a model neglecting other forces such as friction, gravity, etc .:
• the corresponding driving forces can be determined and commanded with the detected speed during contacting and the required stopping at x s .
• the desired pose x s need not be calculated.
• the speed of the robot 1 or its contact area when contacting and the determined spring stiffness c can be determined, in particular model-based prognoses, when the setpoint force F s is reached, and with the braking accordingly early (er) or Late (he) started and / or
• braking is started at Xb before the setpoint force F s is reached at x s , but only after the moving robot 1 contacts the contact point 2. Equally, especially at high contact stiffness as indicated by c ' 2 > c 2 by way of example, the braking of the moving robot 1 by whose drives 5 for impressing the setpoint force F s on the contact point 2 'by the stopped robot are already started at x'b, even before the moving robot contacts the contact point 2' at x c .
• the contact stiffness can be selected based on or depending on the pose of the robot 1 or can be interpolated or extrapolated between multiple contact stiffnesses. Depending on the pose of the robot 1, it contacts the contact point 2 or 2 ', so that in each case the specific position-specific contact stiffness c or c' determined for this purpose can be selected in step S20. In another pose, these contact stiffnesses c, c 'can be interpolated or extrapolated.

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• Engineering & Computer Science (AREA)
• Robotics (AREA)
• Mechanical Engineering (AREA)
• Automation & Control Theory (AREA)
• Human Computer Interaction (AREA)
• Manipulator (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=62196546

Family Applications (1)

Country Status (6)

Families Citing this family (4)

Family Cites Families (27)

• 2017
  • 2017-06-13 DE DE102017005581.5A patent/DE102017005581B4/de active Active
• 2018
  • 2018-05-14 US US16/622,642 patent/US11260527B2/en active Active
  • 2018-05-14 KR KR1020197038872A patent/KR102542089B1/ko active IP Right Grant
  • 2018-05-14 EP EP18725454.5A patent/EP3638462A1/de not_active Withdrawn
  • 2018-05-14 WO PCT/EP2018/062335 patent/WO2018228762A1/de unknown
  • 2018-05-14 CN CN201880038977.9A patent/CN110730706B/zh active Active
• 2022
  • 2022-01-14 US US17/576,406 patent/US11648665B2/en active Active

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