Control unit for robots

1. A control unit for a robot, comprising:

an inverter which drives a motor installed in a robot;

a control circuit that generates a command to control, via the inverter, drive of the motor, the drive of the motor including acceleration and deceleration of the motor;

a drive power circuit which converts AC (alternating-current) power to DC (direct-current) power and supplies the converted DC power to the motor;

a control power circuit which converts AC power to DC power and supplies the converted DC power to the control circuit:

a backup power circuit which supplies backup DC power to the control circuit when the DC power from the control power circuit to the control circuit is shut down, wherein the backup power circuit is charged continuously, at least, before the DC power to the control circuit is shut down; and

a switch circuit provided with a first switch and a second switch, the first switch being arranged in a path electrically connecting the backup power circuit and the inverter, the second switch being arranged in a path electrically connecting the drive power circuit and the backup drive circuit, each of the first switch and the second switch being selectively switched on and off to open and close,

wherein the control circuit comprises a first switch control section and a second switch control section, the first switch control section switching on the first switch to close the path such that the DC power in the backup power circuit is supplementarily supplied to the inverter when the motor is driven to be accelerated in response to the command from the control circuit, and the second switch control section switching off the first switch such that the DC power to the inverter is disenabled and switching on the second switch such that regenerative power from the inverter is used to charge the backup power circuit when the motor is driven to be decelerated.

2. The control unit of claim 1 , wherein the control circuit is configured to analyze a control program to control the drive of the motor, analyzing the control program enabling the first switch control section to know a drive pattern of the motor, and

the first switch control closes the first switch according to the drive pattern before start of the acceleration of the motor.

3. The control unit of claim 2 , wherein the motor is composed of a plurality of electric motors respectively arranged at joints of the robot and the inverter is composed of a plurality of inverters driving the respective motors, and

the control circuit is configured to analyze a control program to control the drive of the motors, analyzing the control program enabling the first switch control section to know a designated motor which is subjected to the power supply from the backup power circuit and a drive pattern of the designated motor, and

the first switch control closes the first switch according to the drive pattern before start of the acceleration of the designated motor.

4. The control unit of claim 1 , comprising a path electrically connecting the control power circuit and a DC-DC conversion circuit supplying DC power to the control circuit,

wherein the backup power circuit is arranged in the path connecting the control power circuit and the DC-DC conversion circuit such that the backup power circuit is charged continuously by the power supplied from the control power circuit to the DC-DC conversion circuit.

5. The control unit of claim 1 , comprising a path electrically connecting the control power circuit and a DC-DC conversion circuit supplying DC power to the control circuit,

wherein the backup power circuit is arranged in the path connecting the control power circuit and the DC-DC conversion circuit such that the backup power circuit is charged continuously by the power supplied from the control power circuit to the DC-DC conversion circuit.

6. The control unit of claim 5 , wherein each of the first and second switches has ends, one end of which being electrically connected to the path connecting the control power circuit and the DC-DC conversion circuit, the other end of which being electrically connected to a path electrically connecting the drive power circuit to the inverter.

7. The control unit of claim 2 , comprising a path electrically connecting the control power circuit and a DC-DC conversion circuit supplying DC power to the control circuit, wherein the backup power circuit is arranged in the path connecting the control power circuit and the DC-DC conversion circuit such that the backup power circuit is charged continuously by the power supplied from the control power circuit to the DC-DC conversion circuit.

8. The control unit of claim 7 , wherein each of the first and second switches has ends, one end of which being electrically connected to the path connecting the control power circuit and the DC-DC conversion circuit, the other end of which being electrically connected to a path electrically connecting the drive power circuit to the inverter.

9. The control unit of claim 3 , comprising a path electrically connecting the control power circuit and a DC-DC conversion circuit supplying DC power to the control circuit, wherein the backup power circuit is arranged in the path connecting the control power circuit and the DC-DC conversion circuit such that the backup power circuit is charged continuously by the power supplied from the control power circuit to the DC-DC conversion circuit.

10. The control unit of claim 9 , wherein each of the first and second switches has ends, one end of which being electrically connected to the path connecting the control power circuit and the DC-DC conversion circuit, the other end of which being electrically connected to a path electrically connecting the drive power circuit to the inverter.