A gripping device monitored based on CEMF and a method for controlling the same includes: using a controller to instruct a drive unit to rotate a stepper motor; using the controller to compare the control instruction with a control parameter matrix stored in an access unit; obtaining a CEMF threshold by checking the position of the actual CEMF in the control parameter matrix; using the controller to monitor the actual CEMF; and using the controller to compare the actual CEMF with the threshold, maintaining driving of the stepper motor when the actual CEMF is larger than the threshold, and stopping the stepper motor to maintain the gripping status, when the actual CEMF is smaller than or equal to the threshold. The operation parameters are measured in advance when the stepper motor runs well, which ensures that the objected is stably gripped before abnormality occurs, thus stabilizing the gripping motion.

An electric machine according to the embodiment includes: a motor; a current controller supplying a current to the motor; a detector detecting a position, a speed, or an acceleration of a shaft of the motor; a controller calculating a torque parameter indicating a torque of the motor based on a current instruction that specifies a supply current to the motor and calculating a speed parameter indicating a rotational speed of the shaft of the motor based on a detection result from the detector; and a display part displaying a graph showing a relation between the torque parameter and the speed parameter.

The invention relates to a method to calibrate a handling device (18) including a handling robot or parallel kinematic robot (24), with a tool head (28) suspended from at least two parallel kinematically movable arms (26). Each of the at least two arms comprises an upper arm, which is movable between two end positions about a defined upper-arm swivel axis (38). Each of the at least two arms also comprises a lower arm (40), which is swivelably mounted on the upper arm. The upper arms are brought into approximately corresponding angular positions by detection of load torques and/or of angle positions. First one, than another of the upper arms is brought into one of the two end positions, and the angular position reached is detected and used for the position initialization or angle initialization of the particular upper arm, whereupon the upper arm is returned.

The invention relates to a method to calibrate a handling device (18) including a handling robot or parallel kinematic robot (24), with a tool head (28) suspended from at least two parallel kinematically movable arms (26). Each of the at least two arms comprises an upper arm, which is movable between two end positions about a defined upper-arm swivel axis (38). Each of the at least two arms also comprises a lower arm (40), which is swivelably mounted on the upper arm. The upper arms are brought into approximately corresponding angular positions by detection of load torques and/or of angle positions. First one, than another of the upper arms is brought into one of the two end positions, and the angular position reached is detected and used for the position initialization or angle initialization of the particular upper arm, whereupon the upper arm is returned.

A gripping system which is monitored based on CEMF and a method for controlling the same includes: using a controller to instruct a drive unit to rotate a stepper motor; using the controller to compare the control instruction with a control parameter matrix stored in an access unit; obtaining a CEMF threshold by checking the position of the actual CEMF in the control parameter matrix; using the controller to continuously monitor the actual CEMF; and using the controller to compare the actual counter electromotive force with the obtained corresponding counter electromotive force threshold, stopping the stepper motor and letting the gripper maintain the gripping status when the actual counter electromotive force is smaller than or equal to the counter electromotive force threshold, and maintaining driving of the stepper motor when the actual counter electromotive force is larger than the counter electromotive force threshold.