Abstract: A determination value calculated based on a distance from a work point of a tip of robot arm (10) to virtual straight line (30) passing through an axis of second joint (J2) and an axis of third joint (J3) is compared with a predetermined threshold. A method of calculating deflection compensation amounts for second joint (J2) and third joint (J3) is changed depending on whether the determination value is larger or smaller than the threshold. Second joint (J2) and third joint (J3) are caused to pivot based on the calculated deflection compensation amounts.

Abstract: Load information on a tool to be attached to a robot arm and collision sensitivity are input. Gravitational torque is calculated based on the input load information. A deflection amount of the robot arm is calculated based on the gravitational torque. A correction amount is calculated based on the collision sensitivity input. The deflection amount is corrected while the robot arm moves.

Abstract: An abnormality detection method for detecting an abnormality of an encoder provided for a robot includes: obtaining corrected position information according to commanded position information output from a controller that designates the rotational position of a motor and an output signal output from the encoder; and, determining, after comparing the corrected position information with the detected position information according to the output signal output from the encoder, the abnormality of the encoder, if there is a difference greater than or equal to a predetermined value between the corrected position information and the detected position information. The controller removes a vibration component of the robot corresponding to the weight of an attachment load from the commanded position information and compensates for a time delay to obtain the corrected position information.

Abstract: In an angular velocity calculation block, an angular velocity component is calculated based on a position command for a joint portion. In a kinetic calculation block, a kinetic torque is calculated based on the position command for the joint portion. In a command velocity component reversal detection block, a reversal timing is calculated based on the angular velocity component. In a reverse torque detection block, a reverse torque is calculated based on the kinetic torque and the reversal timing. In a backlash correction amount calculation block, the correction amount of the joint portion is calculated based on the kinetic torque, the reverse torque, and the reversal timing.

Abstract: A robot control device includes the following: a main control unit; a servo control unit, which receives a position command ?c from the main control unit; and a bending correction block (24), which corrects the bending of the reduction gear connected to the servo motor. The bending correction block (24) includes the following: a first position-correction-value calculation means (63), which finds a first position-command correction value ?sgc based on the position command ?c; and a second position-command-correction-value calculation means (64), which finds a second position-command correction value ?skc based on the interference torque ?a. The servo control unit drives the servo motor based on a new position command obtained by adding the first position-command correction value ?sgc and the second position-command correction value ?skc to the position command ?c.

Abstract: Stop and start detection block (63) determines whether or not a joint portion is in a stopped state before a rotation direction of the joint portion is inverted based on stop flag signal (Stop_Flg). When it is determined that the joint portion is in the stopped state, filter processing block (65) changes a frequency component of a correction amount for correcting backlash to a low frequency lower than a predetermined threshold value.

Abstract: When workpiece (W) is brought into a non-gripping state after deflection compensation of robot arm (10) is performed in a gripping state of workpiece (W), the deflection compensation of robot arm (10) is performed in a non-gripping state of workpiece (W). Here, the deflection compensation of robot arm (10) in the non-gripping state of workpiece (W) is performed while a compensation amount is changed to gradually decrease, while hand (18) is moved from a first teaching point to a second teaching point.

Abstract: A robot control method of controlling motion of a robot arm by using a servo motor includes adding d-axis electric current to a motor electric current command (steps 15-6, 15-8) if external temperature is less than or equal to a predetermined value (step 15-3), and if an absolute value of the motor electric current command is less than or equal to a predetermined value (step 15-4), and if a value of detected overload is less than or equal to a predetermined value (step 15-5).

Abstract: A determination value calculated based on a distance from a work point of a tip of robot arm (10) to virtual straight line (30) passing through an axis of second joint (J2) and an axis of third joint (J3) is compared with a predetermined threshold. A method of calculating deflection compensation amounts for second joint (J2) and third joint (J3) is changed depending on whether the determination value is larger or smaller than the threshold. Second joint (J2) and third joint (J3) are caused to pivot based on the calculated deflection compensation amounts.

Abstract: An abnormality detection method of an encoder includes an output step, a control step, an information acquisition step, and an abnormality determination step. The abnormality determination step compares command position information with detection position information of a motor calculated based on an output signal, and determines that the encoder is abnormal in a case where a difference between the command position information and the detection position information of the motor is equal to or more than a predetermined value.

Abstract: In a robot having a first rotary shaft and a second rotary shaft driven by respective motors and extending in the same direction, the second rotary shaft is rotated while vibrating the first rotary shaft that is holding a load directly or indirectly, thereby rotating the first rotary shaft relative to a load. This enables calculating the gravitational torque of the load applied to the first rotary shaft.

Abstract: In an angular velocity calculation block, an angular velocity component is calculated based on a position command for a joint portion. In a kinetic calculation block, a kinetic torque is calculated based on the position command for the joint portion. In a command velocity component reversal detection block, a reversal timing is calculated based on the angular velocity component. In a reverse torque detection block, a reverse torque is calculated based on the kinetic torque and the reversal timing. In a backlash correction amount calculation block, the correction amount of the joint portion is calculated based on the kinetic torque, the reverse torque, and the reversal timing.

Abstract: An abnormality detection method for detecting an abnormality of an encoder provided for a robot includes: obtaining corrected position information according to commanded position information output from a controller that designates the rotational position of a motor and an output signal output from the encoder; and, determining, after comparing the corrected position information with the detected position information according to the output signal output from the encoder, the abnormality of the encoder, if there is a difference greater than or equal to a predetermined value between the corrected position information and the detected position information. The controller removes a vibration component of the robot corresponding to the weight of an attachment load from the commanded position information and compensates for a time delay to obtain the corrected position information.

Abstract: Load information on a tool to be attached to a robot arm and collision sensitivity are input. Gravitational torque is calculated based on the input load information. A deflection amount of the robot arm is calculated based on the gravitational torque. A correction amount is calculated based on the collision sensitivity input. The deflection amount is corrected while the robot arm moves.

Abstract: A robot controlling method for operating an arm using a motor includes: performing, before the arm stops, addition to add a backlash compensation value to a position command which is input to the motor; and performing, in a period during which the robot arm is not in motion, subtraction to reduce the backlash compensation value added to the position command.

Abstract: A first acquisition unit acquires first data on first malfunction of a robot. A second acquisition unit acquires second data on second malfunction of the robot. A first determination unit determines whether or not to store the first data in accordance with the first data. A second determination unit determines whether or not to store the second data in accordance with the second data. A memory stores the first data and the second data. A controller stores the first data in the memory at a first period when the first determination unit determines to store the first data. The controller further stores the second data in the memory at a second period longer than the first period, when the first determination unit determines not to store the first data and the second determination unit determines to store the second data.

Abstract: An external force torque due to a collision as a collision torque estimation value is estimated by subtracting a dynamic torque obtained by an inverse dynamic calculation of a robot from a torque output to a gear reducer by a motor. It is determined that the robot receives an external force if the collision torque estimation value is greater than a predetermined collision detection threshold.

Abstract: A disclosed motor control device includes: a PI controller which controls a velocity of a motor; an input unit which receives specification information including information of a weight and a center of mass of a tool; a calculation unit which calculates a gravitational torque based on the specification information; a storage which stores the gravitational torque output from the calculation unit and an integral value output from the PI controller, and outputs the gravitational torque and the integral value in response to a break signal; and a selection unit which sets, to the PI controller, the integral value output from the storage, according to a collision sensitivity input from the input unit.

Abstract: A robot control device includes the following: a main control unit; a servo control unit, which receives a position command ?c from the main control unit; and a bending correction block (24), which corrects the bending of the reduction gear connected to the servo motor. The bending correction block (24) includes the following: a first position-correction-value calculation means (63), which finds a first position-command correction value ?sgc based on the position command ?c; and a second position-command-correction-value calculation means (64), which finds a second position-command correction value ?skc based on the interference torque ?a. The servo control unit drives the servo motor based on a new position command obtained by adding the first position-command correction value ?sgc and the second position-command correction value ?skc to the position command ?c.

Abstract: A motor control device includes a movement command generation unit, a movement command processing unit, and a control unit. The movement command generation unit outputs a movement command of a motor. The movement command processing unit includes a buffer, a filter, and a processing unit. The buffer holds the movement command. The filter performs filter processing of a constant and generates a new constant. The processing unit performs arithmetic processing based on the movement command held in the buffer and the new constant generated by the filter, and generates and outputs a new movement command proportional to the new constant. The control unit controls the motor based on the new movement command.