A method for reducing vibration of a robot arm includes: a step of mounting at least one inertia actuator and at least one vibration signal capturing unit to a processing end of a robot arm; a step of applying the at least one vibration signal capturing unit to detect a vibration generated at the processing end of the robot arm so as to generate a vibration signal; a step of applying a central processing unit to evaluate the vibration signal and coordinates of the processing end of the robot arm so as to capture at least one set of corresponding control parameters for calculating at least one output force; and, a step of having the inertia actuator to apply the output force to the processing end of the robot arm for counteracting the vibration at the processing end of the robot arm.

A numerical control device of a machine tool recognizes a failure of a vibration detection unit in a relatively short time to minimize damage to functions achieved using the vibration detection unit. A program interpreting unit interprets an automatic tool exchange operation, and a storage unit is instructed to store vibration information V(x) from the vibration detection unit. After the automatic tool exchange operation is finished, the storage unit is instructed to stop storage. When none of the vibration information V(x) stored in the storage unit exceeds a prescribed vibration level, a vibration information analysis unit determines abnormality of the vibration detection unit.

A method and a robot controller for controlling a robot arm, where the robot arm comprises a plurality of robot joints connecting a robot base and a robot tool flange, where each of the robot joints comprises an output flange movable in relation to a robot joint body and a joint motor configured to move the output flange in relation to the robot joint body. The robot arm is controlled based on vibrational properties of at least one external object connected to the robot arm, where the vibrational properties are received via an external object installation interface by generating control signals for said robot arm based on a target motion and the received vibrational properties of the at least one external object, the control signal comprises control parameters for said joint motor.

An apparatus includes vibration data obtainer 30 obtaining data on vibration caused by a tool in cutting, a vibration frequency calculator 22 calculating a vibration frequency of the tool by analyzing the obtained vibration data, a regenerative chatter detector 23 detecting whether regenerative chatter occurs by comparing the calculated vibration frequency of the tool with a spindle rotation number, and a spindle rotation controller 24 gradually decreasing or increasing the spindle rotation number when occurrence of regenerative chatter vibration is detected, and a stable rotation number calculator 25 monitoring variation of the vibration frequency of the tool and determining a spindle rotation number when the variation of the vibration frequency exceeds a predetermined reference value to be a stable rotation number.

The present disclosure relates to a method for online monitoring defect of a milling tool, comprising the steps of: 1) installing a vibration sensor module on a machine tool spindle; 2) acquiring initial sample data; 3) setting a threshold value ΔS.sub.0 with a time interval of T; 4) measuring vibration signals of n blades in x, y and z directions in each period T.sub.0; 5) shaping to obtain n strong vibration cutting wave data respectively formed by n blades in x and y directions in each period T.sub.0; 6) analyzing and processing the strong vibration cutting wave data to obtain the difference ΔS.sub.0.sup./ between the cutting strong vibration wave areas formed by each blade in each period T.sub.0; 7) outputting a blade wear or defect signal to a display alarm module according to the constraint conditions by a data comparing and analyzing module, and giving an alarm by a display alarm module.

A machining environment measurement device, which enables automatic identification of a vibration source which may cause defects in a machined surface based on pieces of vibration data without performing an actual machining process, includes a reference machining data storage unit that stores reference machining data computed based on time-series data of vibration measured in advance in an ideal machining environment; a data acquisition unit that acquires time-series data of vibration of at least a holder attached to a spindle of the machine tool detected by a holder measurement sensor; an analysis unit that analyzes the time-series data and computes feature data indicating a feature of the time-series data; a comparative determination unit that compares the feature data with the reference machining data and determines a machining environment of the machine tool; and a display unit that displays the determination result of the comparative determination unit.

A method for reducing vibration of a robot arm includes: a step of mounting at least one inertia actuator and at least one vibration signal capturing unit to a processing end of a robot arm; a step of applying the at least one vibration signal capturing unit to detect a vibration generated at the processing end of the robot arm so as to generate a vibration signal; a step of applying a central processing unit to evaluate the vibration signal and coordinates of the processing end of the robot arm so as to capture at least one set of corresponding control parameters for calculating at least one output force; and, a step of having the inertia actuator to apply the output force to the processing end of the robot arm for counteracting the vibration at the processing end of the robot arm.

Compensation for an external disturbance can be applied without requiring a model of the external disturbance, and, particularly, the amount of control can be accurately predicted even when the amplitude of a waveform representing changes in a predicted error with respect to time is not constant with respect to time in a case in which the predicted error that is an error between an actually-measured value of the amount of control of a control target and a predicted value periodically changes. A controller compensates a predicted value of the current amount of control using a predicted error of a previous period by taking changes in the amplitude of a waveform representing a predicted error that is an error between an actually-measured value of the amount of control and a predicted value into account.

The present disclosure is directed toward a diagnostic method for a spindle arm of a machine. The method includes rotating the spindle arm of the machine at a first rotational speed, and acquiring, from an accelerometer, data indicative of a vibrational response of the spindle arm operating at the first rotational speed. The accelerometer is disposed along the spindle arm. The method further includes converting the vibrational response to a frequency based response to obtain a first frequency response, determining whether an amplitude of the first frequency response exceeds a diagnostic threshold, and performing a designated correction on the machine in response to the frequency response exceeding the diagnostic threshold.

A machining environment measurement device, which enables automatic identification of a vibration source which may cause defects in a machined surface based on pieces of vibration data without performing an actual machining process, includes a reference machining data storage unit that stores reference machining data computed based on time-series data of vibration measured in advance in an ideal machining environment; a data acquisition unit that acquires time-series data of vibration of at least a holder attached to a spindle of the machine tool detected by a holder measurement sensor; an analysis unit that analyzes the time-series data and computes feature data indicating a feature of the time-series data; a comparative determination unit that compares the feature data with the reference machining data and determines a machining environment of the machine tool; and a display unit that displays the determination result of the comparative determination unit.