Jtekt Corporation

Kazuya Numazaki

Yasuharu Mukai

Hiromichi Ohta

In a motor control device, a velocity feed-forward control portion includes a velocity-side acceleration input portion that outputs received high-order command acceleration as a velocity-side acceleration output; a velocity-side velocity input portion that outputs a received high-order command velocity as a velocity-side velocity output; velocity-side boundary-velocity input portions which are prepared so as to respectively correspond to boundary velocities, and to output velocity-side boundary velocity outputs from the velocity-side boundary-velocity input portions corresponding to the high-order command velocity, the boundary velocities being velocities at boundaries of preset adjacent velocity ranges obtained by dividing a limited velocity range; a velocity-side first weight learning portion that changes velocity-side first learning weights in accordance with a velocity deviation, the velocity-side first learning weights respectively corresponding to velocity-side first outputs; and a velocity-side output portion that outputs, as a second tentative command current, a value obtained by summing velocity-side first multiplication values.

Motor control device

A distal end of a manipulator having a redundancy is constrained so as to leave one degree of freedom, an attitude of the manipulator is changed into a plurality of attitudes that are allowed by the redundancy by outputting joint position command values from a controller to servomotors that drive links that constitute the manipulator of which the distal end is fixed, and calibration is performed by obtaining parameter deviations of a robot constant of the manipulator on the basis of the joint position command values and actual measured values from rotary encoders, which are respectively provided at the servomotors, after each attitude change.

Calibration method and calibration system for robot

A pair of manipulators are caused to take a plurality of attitudes in a state where distal ends of the manipulators are coupled to each other, coordinates of joints between links at each attitude change are acquired on the basis of detection signals, at each attitude change, of rotary encoders provided for servomotors that drive the links of the manipulators, and a position and attitude of an installation point of a slave robot with reference to an installation point of a master robot are calculated on the basis of the joint coordinates acquired at the corresponding attitude change in a forward kinematics manner. A deviation vector for each attitude change between actual measured values of the installation point of the slave robot and the calculated values of the installation point of the slave robot is calculated, and robot constants of both manipulators are identified from the deviation vector.

A CPU of a robot control device calculates load torque based on the inertia force, centrifugal force or Coriolis force, gravity force, friction torque, and actuator inertia torque applied to a joint axis of each link, each time an orientation parameter indicative of the link position and orientation allowed by a redundant degree of freedom is sequentially changed, under a constraint of end-effector position and orientation as target values. The CPU obtains the link position and orientation at which the ratio of the load torque to the rated torque of a rotary actuator provided for each joint is minimized, while the orientation parameter is being changed, and provides a feed-forward value that gives rise to each load torque obtained when the ratio of the load torque to the rated torque of the rotary actuator is minimized, to a control command generated to the rotary actuator of each joint axis for achieving the end-effector position and orientation as target values.

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Chiryu, Japan

Kazuya Numazaki