A control device of a machine tool includes an oscillation command generation part which generates an oscillation command for at least one feed axis based on a rotation speed of a spindle and a position command of the at least one feed axis so that the oscillation command becomes a positive non-integral multiple of the rotation speed and a tool intermittently cuts a workpiece, an oscillation command correction part which corrects the oscillation command using the position of the feed axis, and an addition part which adds the oscillation command corrected by the oscillation command correction part to a position deviation between the position command and the detected position of the feed axis.

Automatic control device controls servo motor. Automatic control device is provided with control section that calculates operation amount of servo motor based on the difference between current value and target value of a control amount of servo motor. Automatic control device is also provided with first filter that outputs first output value after using a first filter coefficient or a second filter coefficient to perform filtering of operation amount calculated by control section. Automatic control device is also provided with second filter, arranged in parallel with first filter, that outputs second output value after using a third filter coefficient to perform filtering of operation amount calculated by control section. Automatic control device is also provided with switching section that switches between first output value of first filter and second output value of second filter and sends one of the output values to servo motor.

A servo control device according to the present invention includes a speed command generation unit, a torque command generation unit, a speed detection unit, a speed control loop, a speed control gain setting unit for setting a speed control gain for the speed control loop, a sinusoidal disturbance input unit for performing a sinusoidal sweep on the speed control loop, a frequency characteristic calculation unit, and a gain adjustment unit. When the speed control loop has fallen into an oscillation state and has become unstable owing to the increased speed control gain, the speed control gain is reduced and the sinusoidal sweep is temporarily stopped. After the speed control loop is stabilized using the speed control gain which is lower than in the unstable state, the sinusoidal sweep is restarted.

A control device of a machine tool includes an oscillation command generation part which generates an oscillation command for at least one feed axis based on a rotation speed of a spindle and a position command of the at least one feed axis so that the oscillation command becomes a positive non-integral multiple of the rotation speed and a tool intermittently cuts a workpiece, an oscillation command correction part which corrects the oscillation command using the position of the feed axis, and an addition part which adds the oscillation command corrected by the oscillation command correction part to a position deviation between the position command and the detected position of the feed axis.

A system for tuning a control system uses a simplified tuning procedure to generate robustly stabilizing tuning parameters that reduce or eliminate undesired system oscillations in the presence of long system dead times or phase lag. A control method is used to establish a relationship between the plant parameters of a controlled system and the tuning parameters of a parameterized active disturbance rejection controller determined to be optimal or substantially optimal for the control system. The plant parameters include the system gain, time constant, and dead time. Corresponding tuning parameters include the controller bandwidth and a system gain estimate. Using the system gain estimate as a tuning parameter can alleviate the influence of large dead times or phase lags on system response. Once established, these fixed relationships can be used to determine suitable tuning parameters for specific motion or process control applications based on the system gain and dominant constraints of the system.

A robot includes a robot arm and an inertial sensor provided in the robot arm. The robot arm is controlled using a weighting value for weighting output from the inertial sensor. In at least apart of a range in which the robot arm is movable, the weighting value is a first value when acceleration of the robot arm is first acceleration, and changes from the first value to a second value higher than the first value when the acceleration of the robot arm changes from the first acceleration to second acceleration lower than the first acceleration.

A method is proposed for identifying the cause of oscillations in a cascaded control loop of a control valve in a controlled process plant, including the following steps: Setpoint value and actual value of the control valve are determined over time. The setpoint value and actual value are checked to see whether they exhibit a continuous oscillation. If an oscillation is detected, the amplitude and period duration are determined. If only the actual value or only the setpoint value oscillates, the period duration is compared with a characteristic period duration of the control valve. If the actual value and setpoint value oscillate, the amplitudes are compared with each other and/or the period duration is compared with a characteristic period duration of the control valve. The cause of the oscillations is identified from the comparisons. With this method, the cause of oscillations in a control loop of a control valve can be narrowed down so that the effort required for troubleshooting in the plant is reduced. Production downtimes can be minimized and costs avoided.

Automatic control device controls servo motor. Automatic control device is provided with control section that calculates operation amount of servo motor based on the difference between current value and target value of a control amount of servo motor. Automatic control device is also provided with first filter that outputs first output value after using a first filter coefficient or a second filter coefficient to perform filtering of operation amount calculated by control section. Automatic control device is also provided with second filter, arranged in parallel with first filter, that outputs second output value after using a third filter coefficient to perform filtering of operation amount calculated by control section. Automatic control device is also provided with switching section that switches between first output value of first filter and second output value of second filter and sends one of the output values to servo motor.

A robot includes a robot arm and an inertial sensor provided in the robot arm. The robot arm is controlled using a weighting value for weighting output from the inertial sensor. In at least apart of a range in which the robot arm is movable, the weighting value is a first value when acceleration of the robot arm is first acceleration, and changes from the first value to a second value higher than the first value when the acceleration of the robot arm changes from the first acceleration to second acceleration lower than the first acceleration.

An example implementation involves receiving measurements from an inertial sensor coupled to the robot and detecting an occurrence of a foot of the legged robot making contact with a surface. The implementation also involves reducing a gain value of an amplifier from a nominal value to a reduced value upon detecting the occurrence. The amplifier receives the measurements from the inertial sensor and provides a modulated output based on the gain value. The implementation further involves increasing the gain value from the reduced value to the nominal value over a predetermined duration of time after detecting the occurrence. The gain value is increased according to a profile indicative of a manner in which to increase the gain value of the predetermined duration of time. The implementation also involves controlling at least one actuator of the legged robot based on the modulated output during the predetermined duration of time.