A system and method for reducing mechanical oscillations in a multi-axis control system provides a first command for a dynamic notch filter at a first update rate to multiple motor drives. Each motor drive is operatively connected to a motor for an axis in the multi-axis control system. Each motor drive receives a second command for desired operation of the motor at a second update rate. Operation of the dynamic notch filter in each motor drive is changed as a function of the first command at the first update rate, and each motor drive generates a desired output voltage for desired operation of the motor at a third update rate. The third update rate is faster than the second update rate, the second command is passed through the dynamic notch filter to generate a filtered command, and the desired output voltage is generated as a function of the filtered command.

Motion control of a robot arm is performed via a reducer connected to a motor. A controller thereof includes a thrust control unit that generates motor position command value based on an input thrust command value, and a motor control unit that generates a current value based on the motor position command value. The motor control unit feeds back a motor position detected by a motor encoder, and the thrust control unit feeds back thrust detected by a thrust meter. The feedback from the motor control unit suppresses vibration phenomena at the reducer, and the feedback from the thrust control unit suppresses transmission error, thereby enabling motion control of the arm with rapidity and precision.

Motion control of a robot arm is performed via a reducer connected to a motor. A controller thereof includes a thrust control unit that generates motor position command value based on an input thrust command value, and a motor control unit that generates a current value based on the motor position command value. The motor control unit feeds back a motor position detected by a motor encoder, and the thrust control unit feeds back thrust detected by a thrust meter. The feedback from the motor control unit suppresses vibration phenomena at the reducer, and the feedback from the thrust control unit suppresses transmission error, thereby enabling motion control of the arm with rapidity and precision.

A robot includes a yielding element for mechanically coupling first and second arm segments of a robot arm. A motor moves the second arm segment relative to the first arm segment. A sensor determines a relative position of the first arm segment in relation to the second arm segment and outputs a position sensor signal representing the relative position. A control unit controls the motor in accordance with the position sensor signal such that the first arm segment is moved into a desired relative position in relation to the second arm segment, when no external force is applied to the robot arm, and when an external force is applied to the robot arm, the motor generates a counterforce which depends on the deviation between the actual and desired positions. The control unit has a predetermined time constant so that changes in the external force are substantially absorbed by damping elements.

In an industrial robot, correction is made for change in position and attitude of an arm distal end due to mechanical deflection of the robot. In the robot, a moment applied to the first axis in its non-rotation direction opposite to its rotation direction is calculated from a load torque applied to the second axis in its rotation direction, a moment due to a second-axis-side self-weight, and a ratio of a distance between the rotation centers of the first and second axes, to a distance between the rotation centers of the second axis and a tool. A deflection amount indicating an angle of the first axis tilting in the non-rotation direction is calculated from the moment applied to the first axis and the rigidity of the first axis in the non-rotation direction. A control value is corrected based on the deflection amount to control the robot.

According to one embodiment, a robot control device is used for a robot arm including a link and a motor for rotationally driving the link. The robot control device includes a derivation part. The derivation part derives a first estimated value including a variation of a rotation angle of the link and a second estimated value including a variation of a rotation angle of the motor, based on an angular velocity and a current reference value of the motor. Furthermore, the derivation part derives an external force generated to the robot arm, based on a difference between the first estimated value and the second estimated value.

A method and system for determining at least one property associated with a selected axis of a manipulator (2). The elasticity of the links (4, 6, 9, 10, 13, 14) and joints (3, 5, 7, 8, 11, 12) of a manipulator (2) can be modeled and the resulting compliance can be determined. A certain method is used to control the manipulator (2) such that certain quantities related to actuator torque and/or joint position can be determined for a certain kinematic configuration of the manipulator (2). Depending on the complexity of the manipulator (2) and the number of properties that are of interest, the manipulator (2) is controlled to a plurality of different kinematic configurations in which configurations the quantities are determined. Thereafter, a stiffness matrix (K) for each component of the manipulator (2) can be determined, and a global stiffness matrix (MSM) for the total manipulator (2) can be determined in order to determine at least one property of the selected axis.

The invention relates to a method (200) for controlling an angular position of an output shaft in a drive unit (100), comprising the steps of: detecting a change in direction of a drive apparatus (5), detecting the torque transmitted by a flexible ring (6.3) of a strain wave gear immediately upon detection of the change in direction by means of a second sensor (12), determining a drive period of the drive apparatus (5) until the expected attainment of a transmission torsion (14.1, 14.2) of the flexible ring (6.3) on the basis of the first torque, driving a drive shaft (4) by means of the drive apparatus (5) over the drive period, detecting a change in angular position of the output shaft immediately after the end of the drive period by means of a first sensor (11.1), and controlling the drive apparatus using the first sensor (11.1) following the drive period when a change in angular position is detected.

This control device (10) for compensating for the elastic deformation of an articulated robot is configured from a joint angle command value calculation unit (100), an axial force torque calculation unit (200), a first dynamic characteristic computing unit (300), a feedback control unit (500), and a motor angle command value calculation unit (600). The first dynamic characteristic computing unit (300) is configured from an interpolation unit configured from an N-ary curve interpolation, and a filter unit configured from an M-ary filter, with N+M being at least 4.

It is proposed a design and control of series elastic holonomic mobile platform, aimed to administer therapeutic table-top exercises to patients who have suffered injuries that affect the function of their upper extremities. The proposed mobile platform is a low-cost, portable, easy-to-use rehabilitation device for home use. It consists of four actuated Mecanum wheels and a compliant, low-cost, multi degree-of freedom Series Elastic Element as its force sensing unit. Thanks to its series elastic actuation, it is highly backdriveable and can provide assistance/resistance to patients, while performing omni-directional movements on plane. The device helps improving accuracy and effectiveness of repetitive movement therapies completed at home, while also providing quantitative measures of patient progress.