Method and system for stopping of axes of an industrial robot
AssigneeKUKA Roboter GmbH
InventorsTorsten Geiler, Richard Rudolf
Life of this patent
Estimating the term…
Abstract
The invention relates to a method or a system for the dependable stopping of axes of an industrial robot. The industrial robot comprises a control device (501, 502), power electronics (201, 202, 203) and a DC source (300), as well as at least one axis (700), which is assigned to an electric motor (100) and to a mechanical brake (600). In order to stop the axis a direct current is supplied by the DC source in at least one motor phase of the motor, which generates a braking torque.
Claims17
A method for stopping movement of axes of an industrial robot, wherein the industrial robot comprises at least one control device, power electronics, a DC source and at least one axis which is assigned to an electric motor that is equipped with a mechanical brake, and wherein the control device is configured to actuate the electric motor via the power electronics using control signals (ÿref), the method including the steps of:
- a) sending a signal from the control device to the mechanical brake to stop movement of the robot in the at least one axis;
- b) sending a signal to activate a short-circuit braking of the motor assigned to the at least one axis, whereby the motor phases are short-circuited to generate a braking torque that depends on a rotational speed of the electric motor at the time when the motor phases are short circuited;
- c) after activating the short-circuit braking of the motor, sending a signal to the DC source to activate a direct current braking of the motor before the mechanical brake takes effect;
- and
- d) in response to the signal of step c), supplying a direct current from the DC source in at least one motor phase of the motor assigned to the at least one axis to generate a braking torque that is independent of the rotational speed of the motor.
A system for controlling an industrial robot, in particular for stopping movement of axes of the industrial robot, wherein the industrial robot has:
- at least one axis which is assigned to an electric motor that is equipped with a mechanical brake;
- a control device;
- and
- power electronics, wherein:
- the control device is configured to actuate the motor via the power electronics using control signals and to send signals to stop movement of the at least one axis,
- the signals to stop movement of the at least one axis bring about the activation of the mechanical brake and an electrical braking of the motor assigned to the at least one axis,
- the system additionally comprises a DC source for the electrical braking, the DC source being connected to the motor so as to supply direct current in at least one motor phase of the motor assigned to the at least one axis in order to generate a braking torque that is independent of the rotational speed of the motor, and
- the control device is configured to bring about the electrical braking of the motor before the intervention of the mechanical brake.
Dependencies are inferred from the claim text.