Control device, mechanical system, and time synchronization method

A control device configured to control a mechanical device having a movable member to be driven by a motor, the control device comprising:

• a radio signal exchange unit configured to receive a sensor signal indicating a position, a velocity or an acceleration of a tip part of the movable member of the mechanical device periodically detected by a sensor part arranged to the tip part;
• a data acquisition unit configured to acquire first time-series data of acceleration at the tip part of the movable member, on the basis of the position, the velocity or the acceleration in the received sensor signal;
• a data calculation unit configured to calculate second time-series data of acceleration at the tip part of the movable member corresponding to the first time-series data, on the basis of a drive command to the motor;
• a delay time calculation unit configured to calculate, when the mechanical device is made to perform an operation indicated in a program to be executed by the control device at a velocity equal to or less than a predetermined value instead of a velocity indicated in the program, a delay time of the first time-series data acquired by the data acquisition unit with respect to the second time-series data calculated by the data calculation unit, on the basis of a degree of correlation between the first time-series data and the second time-series data;
• and
• a time synchronization unit configured to synchronize time of the sensor part and time of the control device, on the basis of the delay time calculated by the delay time calculation unit.

A time synchronization method for performing, in a mechanical system including a mechanical device having a movable member to be driven by a motor and a control device for controlling the mechanical device, time synchronization between a sensor part arranged to a tip part of the movable member of the mechanical device and the control device, the time synchronization method comprising:

• a radio signal exchanging step of receiving a sensor signal indicating a position, a velocity or an acceleration of the tip part periodically detected by the sensor part;
• a data acquiring step of acquiring first time-series data of acceleration at the tip part of the movable member, on the basis of the position, the velocity or the acceleration in the received sensor signal;
• a data calculating step of calculating second time-series data of acceleration at the tip part of the movable member corresponding to the first time-series data, on the basis of a drive command to the motor;
• a delay time calculating step of calculating, when one motor, which is arranged closest to the tip part of the movable member to which the sensor part is arranged, of a plurality of motors including the motor of the mechanical device is driven to rotate the tip part of the movable member, a delay time of the first time-series data acquired in the data acquiring step with respect to the second time-series data calculated in the data calculating step, on the basis of a degree of correlation between the first time-series data and the second time-series data;
• and
• a time synchronizing step of synchronizing time of the sensor part and time of the control device, on the basis of the delay time calculated in the delay time calculating step.

A time synchronization method for performing, in a mechanical system including a mechanical device having a movable member to be driven by a motor and a control device for controlling the mechanical device, time synchronization between a sensor part arranged to a tip part of the movable member of the mechanical device and the control device, the time synchronization method comprising:

• a radio signal exchanging step of receiving a sensor signal indicating a position, a velocity or an acceleration of the tip part periodically detected by the sensor part;
• a data acquiring step of acquiring first time-series data of acceleration at the tip part of the movable member, on the basis of the position, the velocity or the acceleration in the received sensor signal;
• a data calculating step of calculating second time-series data of acceleration at the tip part of the movable member corresponding to the first time-series data, on the basis of a drive command to the motor;
• a delay time calculating step of calculating, when the mechanical device is made to perform an operation indicated in a program to be executed by the control device at a velocity equal to or less than a predetermined value instead of a velocity indicated in the program, a delay time of the first time-series data acquired in the data acquiring step with respect to the second time-series data calculated in the data calculating step, on the basis of a degree of correlation between the first time-series data and the second time-series data;
• and
• a time synchronizing step of synchronizing time of the sensor part and time of the control device, on the basis of the delay time calculated in the delay time calculating step.