JP5376021B2 - Robot controller - Google Patents

Description

  The present invention relates to a robot controller having a configuration in which power is branched and supplied from a power source to a robot power and a controller power source.

  A robot system used in a production line of a factory is provided with a robot main body and a controller for driving and controlling the robot main body. In this case, it is common to generate a robot power source and a controller power source from the same power source. Further, along with the promotion of downsizing of the production line, downsizing of the robot body and controller is required for the robot system.

  FIG. 6 shows an electrical configuration including a controller 2 for performing drive control of a conventional robot body 1. Power is supplied from the three-phase AC power supply AC to the contactor 5 through the current fuse 3 and the circuit protector 4, and the DC power converted through the rectifier circuit 6 and the smoothing circuit 7 is supplied to the drive circuit 8. The drive circuit 8 is configured to include an inverter main circuit in which switching elements are bridge-connected, and a drive control signal is given from the controller CPU 9.

  The controller 2 includes a rectifier circuit 10 and a smoothing circuit 11 and is supplied with power from an AC power supply AC through a current fuse 3. The DC output from the smoothing circuit 11 is converted into a DC voltage necessary for the controller CPU 9 and the like in the step-down power supply circuit 12. The step-down power supply circuit 12 includes a primary coil having a switching element 13 connected in series, a transformer 14 having a secondary coil for generating a necessary voltage, and a DC power supply circuit 15 for converting to DC. Yes. The switching element 13 is supplied with an on / off drive signal from the switching IC 16.

  The switching IC 16 is supplied with power from the resistance voltage dividing circuit using the DC output supplied from the smoothing circuit 11 as a power supply, and generates an AC input that is stepped down to the DC power supply circuit 15 side via the transformer 14 by controlling the on / off of the switching element 13. . When the DC power supply circuit 15 outputs a predetermined DC voltage, the controller CPU 9 and the switching IC 16 are given normal DC power.

  When the power supply CPU 17 receives a power failure detection signal from the power failure detection determination circuit 18 connected to the two power supply lines of the three-phase AC power supply AC, the power supply CPU 17 gives a power-off treatment signal to the controller CPU 9 to provide the robot body 1. To perform a predetermined stop operation.

  In the above configuration, the power supply of the robot body 1 is turned on and off by turning on and off the circuit protector 4. However, since the power supply of the robot drive system is a line to which a high voltage of 200 V or more is applied, the circuit protector 4 generates a large current. A configuration for flowing was necessary. For this reason, the cost for providing the circuit protector 4 was high.

  In contrast to the configuration in which the circuit protector 4 is used to directly connect and disconnect the power supply as in the above configuration, for example, in Patent Document 1, the semiconductor switching element is electrically controlled for disconnection and disconnection. A configuration to perform is disclosed. This eliminates the need for a physical configuration related to electrical contact.

JP 2001-196908 A

  However, in the conventional configuration described above, when a semiconductor switching element is used for control of power interruption, the same high cost is caused in that it is still necessary to cut off a large current.

  The present invention has been made in consideration of the above circumstances, and an object of the present invention is necessary when turning on and off the power supply to the robot body side in a robot apparatus configured to distribute power from a robot power supply and a control power supply from the same power supply. It is an object of the present invention to provide a robot controller that can realize such a configuration with an inexpensive configuration that does not require consideration of a large current.

  According to the first aspect of the present invention, the three-phase AC power input is configured to be branched and supplied to the robot power and the controller power via the branch circuit, and the robot power is supplied when the contactor is turned on. Power is supplied to the robot body, and the controller power is supplied to the converter circuit.

  In this state, when the power switch is turned on, the switching control circuit starts to operate using the DC output generated from the smoothing capacitor by the power supply to the diode bridge as the operating power, and the switching elements of the converter circuit are controlled to be turned on and off. The control power supply is supplied to the CPU and the operation power supply is switched to supply power from the converter circuit. Then, the contactor is turned on by the CPU to supply power for the robot to the robot body, and the operation control is performed. The operation control state is continued while the power supply monitoring unit detects the power supply state.

  When the power switch is turned off, the CPU determines that the switch is turned off by detecting the power supply stop to the diode bridge by the power supply monitoring means, and stops the robot body during the period when the charge of the smoothing capacitor is used as the power supply. The contactor is turned off after the control is executed.

  As a result, the contactor can be turned on / off by turning on / off the power switch provided in the energization path of the controller power supply. The required configuration can be realized as an inexpensive configuration that does not require consideration of a large current.

1 is an electrical configuration diagram of a power feeding system showing a first embodiment of the present invention. Perspective view showing the configuration of the robot system Diagram showing the relationship between the capacitor terminal voltage and transistor on / off status Electrical configuration diagram of a step-down power supply circuit showing a second embodiment of the present invention FIG. 1 equivalent view showing a third embodiment of the present invention 1 equivalent diagram showing a conventional example

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected about the structure similar to the structure shown in FIG. 6 corresponding to the former, and description is simplified.

  FIG. 2 shows a system configuration of a general industrial robot. The robot system shown in FIG. 2 includes a robot body 1, a controller 20 that controls the robot body 1, a teaching pendant 21 connected to the controller 20, and a display device 22 mainly composed of, for example, a liquid crystal display. Has been. The controller 20 is provided with a power switch 20a corresponding to a physical switch. The teaching pendant 21 functions as an input means for inputting various data and an operating means for remotely operating the robot body 1 in addition to the function of teaching the operating point of the robot arm, and includes various operation switches 21a and a display unit. 21b.

  The robot body 1 is configured as an articulated type, and is supported by a base 23, a shoulder portion 24 supported by the base 23 so as to be turnable in the horizontal direction, and supported by the shoulder portion 24 so as to be turnable in the vertical direction. The lower arm 25, the upper arm 26 supported by the lower arm 25 so as to be turnable in the vertical direction and rotatable (twisting), and the wrist 27 supported by the upper arm 26 so as to be capable of turning in the vertical direction. It is configured. The wrist 27 includes a flange 28 that can be rotated (twisted) at the tip. The shoulder portion 24, the lower arm 25, the upper arm 26, the wrist 27 and the flange 28 constitute a robot arm, and a camera 29 is attached to the flange 28 which is a tip portion of the arm tip.

  Next, an electrical configuration of the controller 20 mainly including a power supply system in the robot system having the above configuration will be described with reference to FIG. In this embodiment, power is supplied directly to the contactor (electromagnetic contactor) 5 from the three-phase AC power supply AC (for example, 200 V or 250 V) via the current fuse 3, and the circuit protector is not provided. is there. The contactor 5 is connected to the rectifier circuit 6 and the smoothing circuit 7, and the three-phase AC power supply AC is converted into a DC power supply and supplied to the drive circuit 8. The drive circuit 8 is mainly composed of an inverter main circuit formed by bridge-connecting switching elements such as FETs, IGBTs or bipolar transistors, and a drive control signal is given from the controller CPU9. The contactor 5 is switched between an on state and an off state in response to an on / off control signal from the controller CPU 9.

  The controller 20 is fed from the power supply path from the AC power supply AC through the current fuse 3 to the robot body 1 (corresponding to a branch circuit), and is connected to the rectifier circuit 10 and the smoothing circuit 11 including a smoothing capacitor. . The direct current output from the smoothing circuit 11 is converted into a direct current voltage necessary for the controller CPU 9 and other control circuits in the step-down power supply circuit 12. The step-down power supply circuit 12 includes a switching element 13, a transformer 14 having a primary coil and a step-down secondary coil connected in series with the switching element 13, and a DC power supply circuit 15 for converting to DC. . The switching element 13 is provided so as to function also as a converter cutoff circuit. The switching element 13 includes an FET, an IGBT, or a bipolar transistor, and an ON / OFF drive signal for performing step-down conversion by the transformer 14 is given from the switching IC 16.

  In the switching control circuit 31, a resistance voltage dividing circuit 33 including a series circuit of resistors 33a and 33b is connected from a positive terminal of the smoothing circuit 11 via a diode 32 for preventing backflow, and a terminal voltage of the resistor 33b is input to a power source. It is the structure given as. A capacitor 34 is connected in parallel to the resistor 33b, and a terminal voltage generated in the resistor 33b is applied via a pnp transistor 35. The transistor 35 functions as a switching control circuit cutoff circuit, and is supplied with power from a terminal for outputting a predetermined DC voltage of the DC power supply circuit 15 of the step-down power supply circuit 12 via a diode 36 for preventing backflow. The transistor 35 is supplied with an on / off signal from the delay circuit 37 to the base terminal via the resistor 38.

  The delay circuit 37 includes a time constant circuit 39 and a comparator 40. The time constant circuit 39 includes resistors 39a and 39b and a capacitor 39c. The resistor 39a and the capacitor 39c constitute an integrating circuit, and the resistor 39b and the capacitor 39c constitute a discharge circuit. The comparator 40 has a configuration in which the reference voltage is supplied from the voltage dividing circuit 41 of the resistors 41a and 41b.

  The power switch 20a includes an operation knob 42, a first contact 43a, and a second contact 43b. The first contact 43a and the second contact 43b are simultaneously turned on / off according to the on / off operation of the operation knob 42. One end of the first contact 43 a is connected to the common connection point of the resistors 33 a and 33 b of the resistance voltage dividing circuit 33, and the other end is connected to the resistor 39 a of the time constant circuit 39. The second contact 43 b has one end connected to the output terminal DC of the DC power supply circuit 15 and the other end connected to the control input terminal of the controller CPU 9.

Next, the operation of the above configuration will be described with reference to FIG.
When the power switch 20a is in the off state, the contactor 5 is in the off state, so that the power supply from the AC power source AC is cut off by the contactor 5 on the robot body 1 side. On the controller 20 side, power from the AC power supply AC is supplied to the rectifier circuit 10 via the current fuse 3. A DC output obtained by rectifying and smoothing an AC input is generated between terminals of the smoothing circuit 11. Thereby, on the controller 20 side, a divided voltage output is generated as a standby power supply to the resistance voltage dividing circuit 33 via the diode 32. At this time, since the transistor 35 is still in the OFF state, the switching IC 16 is not operating. Further, since the step-down power supply circuit 12 is also in the off state, no DC output is generated at the output terminal of the DC power supply circuit 15.

  In the above state, first, when the operation knob 42 of the power switch 20a is turned on to turn on the power, both the first contact 43a and the second contact 43b are turned on. In this case, when the first contact 43a is turned on, the DC voltage generated between the terminals of the smoothing circuit 11 is applied to the resistance voltage dividing circuit 33 via the diode 32, and the output is divided into a predetermined DC voltage. Is given to the time constant circuit 39 side of the delay circuit 37.

  3A and 3B show the transition of the terminal voltage Vin (input voltage of the comparator 40) of the capacitor 39c of the time constant circuit 39 and the operation state of the transistor 35 in accordance with the on / off operation of the power switch 20a. In the delay circuit 37, charging of the capacitor 39c is started via the resistor 39a as the power switch 20a is turned on. When the time Td1 elapses and the terminal voltage Vin of the capacitor 39c reaches a predetermined level, the comparator 40 Since the input level exceeds the reference voltage provided by the resistor 41b, the output is inverted from the high level to the low level.

  As a result, the transistor 35 is turned on with the base potential lowered (see FIG. 3B), and the power supply path to the switching IC 16 becomes conductive. Since the terminal voltage of the smoothing circuit 11 is supplied via the diode 32 and the resistor 33a transistor 35, the switching IC 16 starts a predetermined switching operation. As a result, the switching element 13 provided in the primary coil of the transformer 14 of the step-down power supply circuit 12 is turned on and off at a predetermined frequency, and a converted output of a voltage corresponding to the turn ratio is generated on the secondary coil side. The DC power supply circuit 15 converts an AC input input from the secondary coil side of the transformer 14 into a predetermined DC voltage and supplies it to each output terminal. As a result, the switching IC 16 is kept in the power supply state from the output side of the DC power supply circuit 15 via the diode 36.

  On the other hand, when the second contact 43b of the power switch 20a is turned on, the voltage of the DC voltage DC output from the DC power supply circuit 15 is input to the control input terminal of the controller CPU 9 via the second contact 43b as an ON control signal. . Thereby, the controller CPU 9 starts a control operation for the robot body 1. First, an ON signal is output to the contactor 5 to shift the contactor 5 to an ON state, and a DC power supply is generated as a power supply for the robot by the rectifier circuit 6 and the smoothing capacitor 7. In addition, the controller CPU 9 gives a PWM signal to the drive circuit 8 to drive and control motors provided in each part of the robot body 1. This operation control is performed according to a program for controlling the operation separately.

  Next, when the operation knob 42 of the power switch 20a is turned off to stop the operation of the robot body 1, both the first contact 43a and the second contact 43b are turned off. In this case, when the second contact 43b is turned off, the controller CPU 9 stops the on-control signal (corresponding to the off-control signal), and controls the robot body 1 to stop the operation. In this case, the stop operation is an operation for moving the lower arm 25 and the upper arm 26 to a predetermined safe position in the operation state of the robot body 1. Thereafter, the controller CPU 9 gives an OFF signal to the contactor 5 to turn it off, and stops the supply of power for the robot.

  On the other hand, when the first contact 43a of the power switch 20a is turned off, the charging operation of the time constant circuit 39 is stopped in the delay circuit 37, so that the charge of the capacitor 39c is discharged through the resistor 39b. Along with this, the terminal voltage Vin of the capacitor 39c decreases as shown in FIG. 3A, and when the delay time Td2 elapses, the output of the comparator 40 shifts to a high level. As a result, the transistor 35 is turned off, and the switching IC 16 stops supplying power and stops the switching operation of the switching element 13. As a result, the operation of the step-down power supply circuit 12 is also stopped, and the DC power supply output becomes zero. In addition, the power supply of the controller CPU 9 is also stopped thereby, so that the control operation is stopped.

  Note that, in addition to the above-described on / off operation by the normal power switch 20a, the power supply CPU 17 determines that the power supply of the AC power supply AC has been stopped in an unexpected situation such as a power failure. A power failure detection determination circuit 18 connected to two of the three-phase power supply lines gives a power failure detection signal to the power supply CPU 17 when the voltage between the terminals has become a predetermined level or less due to a power failure. Then, the power supply CPU 17 gives a power-off treatment signal to the controller CPU 21 to cause the robot 1 to perform the predetermined stop operation as described above.

  In addition, when an overcurrent flows to either the robot power supply or the controller power supply to the robot body 1, the current fuse 3 temperature rises due to the overcurrent and blows when the temperature rises above a certain condition. As a result, the power outage state described above is exhibited. Therefore, also in this case, the stopping operation is performed in the same manner.

  According to the present embodiment, by providing the power switch 20a for turning on / off the robot power supply to the robot body 1, a large and costly current for supplying a large current to a circuit protector or the like that had to be provided conventionally. It is not necessary to provide such a configuration, and it is possible to secure a control operation for surely performing the stop operation of the robot body 1 at the time of stop, while having a configuration capable of reducing the size and cost.

  Also, depending on the configuration of the robot system, in the case where the circuit protector is provided with an overcurrent protection function, the circuit protector is not provided as in the configuration of the present embodiment, but the overcurrent protection function is lost. By providing the current fuse 3, its function can be ensured.

(Second Embodiment)
FIG. 4 shows a second embodiment of the present invention. The difference from the first embodiment is that a step-down chopper circuit 44 is provided in place of the transformer 14 of the step-down power supply circuit 12 which is a converter circuit. is there. The step-down chopper circuit 44 is provided with a transistor 45 as a switching element at an input terminal on the smoothing circuit 11 side, and is connected to an output terminal via a coil 46. A diode 47 is provided between the emitter of the transistor 45 and the negative terminal of the smoothing circuit 11, and a capacitor 48 is connected between the output terminals.

The transistor 45 is supplied with an on / off signal from the switching IC 16, and thereby generates a predetermined DC voltage stepped down by the capacitor 48 by the operation of the coil 46 and the diode 47. The output terminal is configured to generate a DC power supply DC or the like via a DC power supply circuit to further adjust to a predetermined voltage.
With such a configuration, the same effects as those of the first embodiment can be obtained with a simple and inexpensive configuration.

(Third embodiment)
FIG. 5 shows a third embodiment of the present invention, and only the parts different from the first embodiment will be described below.
A switching control circuit 49 that replaces the switching control circuit 31 has a configuration in which the transistor 35 is omitted. The switching IC 16 is configured to be directly supplied with the DC voltage of the voltage dividing circuit 33 without using a transistor. Further, the delay circuit 37 is omitted from the configuration, and the power switch 20a as a physical switch is provided in the power supply path between the current fuse 3 and the rectifier circuit 10 including the diode bridge. Further, an AC voltage detection device 50 is provided as a power supply monitoring means on the power supply path from the power switch 20a to the rectifier circuit 10, and the controller CPU 9 inputs the detection output of the AC voltage detection device 50 to determine the on / off state of the power switch 20a. It was set as the structure to do. The configuration of the power supply CPU 17 and the determination circuit 18 is also omitted. This is because the function of the power source CPU 17 provided for detecting a power failure can be shared by the controller CPU 9 in this embodiment.

Next, the operation of the above configuration will be described.
When the power switch 20a is in the off state, the contactor 5 is in the off state, so that the power supply from the AC power source AC is cut off by the contactor 5 on the robot body 1 side. In addition, the power source is also cut off on the controller 20 side because the power switch 20a is off.

  In this state, when the operation knob 42 of the power switch 20a is turned on to start the operation of the robot body 1, power is supplied from the AC power supply AC to the rectifier circuit 10 through the current fuse 3, and the smoothing composed of the smoothing capacitor is performed. A dc output converted by rectifying and smoothing an ac input between the terminals of the circuit 11 is generated. As a result, a divided voltage output is generated in the resistance voltage dividing circuit 33 via the diode 32 on the controller 20 side. When the divided voltage output is supplied, the switching IC 16 starts a predetermined switching operation. As a result, the switching element 13 provided in the primary coil of the transformer 14 of the step-down power supply circuit 12 is turned on and off at a predetermined frequency, and a converted output of a voltage corresponding to the turn ratio is generated on the secondary coil side.

  The DC power supply circuit 15 converts an AC input input from the secondary coil side of the transformer 14 into a predetermined DC voltage and supplies it to each output terminal. As a result, the switching IC 16 is kept in the power supply state from the output side of the DC power supply circuit 15 via the diode 36. Further, the controller CPU 9 is supplied with the DC voltage DC output from the DC power supply circuit 15, whereby the controller CPU 9 starts a control operation for the robot body 1.

  First, the controller CPU 9 outputs an ON signal to the contactor 5 to shift the contactor 5 to the ON state, and the rectifier circuit 6 and the smoothing circuit 7 generate DC power as a robot power supply. In addition, the controller CPU 9 gives a PWM signal to the drive circuit 8 to drive and control motors provided in each part of the robot body 1. This operation control is performed according to a program for controlling the operation separately.

  Further, the controller CPU 9 inputs the signal of the detection voltage of the AC voltage detection device 50, and the power switch 20a is turned on, that is, the power supply state of the AC power supply AC is generated when the terminal voltage from the AC power supply AC is generated. Judge that there is. When the power switch 20a is in the on state, the controller CPU 9 continues the control operation of the robot body 1 described above.

  Next, when the operation knob 42 of the power switch 20a is turned off to stop the operation of the robot body 1, the signal of the detection voltage from the AC voltage detection device 50 becomes zero level. It is determined that the power switch 20a is turned off and power supply to the AC power supply AC is stopped. In this state, the controller CPU 9 can perform a control operation while the charge of the smoothing circuit 11, that is, the smoothing capacitor holds a predetermined voltage, so that the operation with respect to the robot body 1 is stopped during this period. To control.

  In this case, the stopping operation is performed by the controller CPU 9 by moving the operation state of the robot body 1 to the lower arm 25 and the upper arm 26 to a predetermined safe position, and then turning off the contactor 5 by giving an off signal, This operation stops the supply of power for the robot. Thereafter, since the power supply by the charge of the smoothing capacitor constituting the smoothing circuit 11 is insufficient, the power supply to the controller CPU 9 itself is also stopped, and the operation of the entire controller 20 is stopped.

  In addition to the above-described on / off operation by the normal power switch 20a, in a situation due to an unexpected situation such as a power failure, even if the power switch 20a is not turned off, the detected voltage by the AC voltage detection device 50 is changed to the power switch 20a. Therefore, the controller CPU 9 performs the same stop operation as described above on the robot main body 1. In this case, as described above, it is a condition that the operation power until the robot body 1 is stopped can be covered by the charge of the smoothing capacitor constituting the smoothing circuit 7.

  According to the third embodiment as described above, as in the first embodiment, a circuit protector or the like that had to be provided conventionally is provided by providing the power switch 20a to turn on and off the robot power to the robot body 1. It is no longer necessary to provide a large and costly structure for energizing a large amount of current, and a control operation that reliably performs the stopping operation of the robot body 1 at the time of stopping can be ensured while the size and cost can be reduced. Can be.

  Further, the charging power of the smoothing capacitor 11 in the configuration of the controller 20 is used to cover the operating power of the controller CPU 9 after the power switch 20a is turned off, so that the standby power of the controller 20 is not required when the power is turned off. In addition, since the functions of the delay circuit 37 and the power source CPU 17 can also be used, the circuit configuration can be further simplified.

  In the above configuration, the AC voltage detection device 50 as the power supply monitoring unit is controlled by the controller CPU 9 when the AC power supply AC detects the power supply stop. However, the present invention is not limited to this. The state in which the power supply AC fluctuates from a predetermined power supply voltage is monitored by the detection voltage, and is also used to preventively control the operation of the robot body 1 so as not to hinder the operation control of the robot body 1 according to the voltage fluctuation state. be able to.

(Other embodiments)
The present invention is not limited to the above embodiment, and can be modified or expanded as follows.

Although the switching element 13 of the converter circuit 12 is configured to be used as a converter cutoff circuit, it can be provided as a separate configuration.
The current fuse 3 may be provided as necessary. For example, when the power supply system is already provided, it is not necessary to provide it.

Although the power supply path to the controller 20 is always supplied with power through the diode 32, the power supply path to the controller 20 may be supplied with a separate switch.
The delay time Td2 of the delay circuit 37 can be set to an appropriate time. This is sufficient as long as the time necessary for stopping and controlling the robot body 1 in a safe state can be secured.

  The voltage detecting means can be used as long as it can determine whether or not AC power is supplied in addition to the AC voltage detecting device 50. For example, it is possible to determine that the voltage of the AC power supply AC is supplied by providing a circuit for detecting that the zero cross signal is periodically generated.

  In the drawings, 1 is a robot body, 3 is a current fuse, 5 is a contactor, 9 is a controller CPU (CPU), 12 is a step-down power supply circuit (converter circuit), 13 is a switching element (converter cutoff circuit), and 16 is a switching IC ( Switching control circuit), 20 is a controller, 20a is a power switch (physical switch), 31, 49 are switching control circuits, 35 is a transistor (switching element, switching control circuit cutoff circuit), 37 is a delay circuit, 43a is a first contact 43b are second contacts, and 50 is an AC voltage detection device (voltage detection means).

Claims (1)

A branch circuit for branching and supplying a three-phase AC power supply input to a three-phase AC power supply for robot power and a single-phase AC power supply for controller power;
A contactor provided in a power supply path from the branch circuit to the robot body;
A CPU (central processing unit) for controlling the operation of the robot body;
A circuit comprising a diode bridge and a smoothing capacitor that rectifies and smoothes the single-phase AC power supplied from the branch circuit and converts it to a DC power;
A power switch provided to be able to cut off power between the branch circuit and the diode bridge;
A converter circuit for converting a direct current output from the smoothing capacitor into a control power source having a predetermined voltage by on / off control of a switching element and supplying the power to the CPU;
A switching control circuit for controlling on / off of the switching element provided in the converter circuit, using a DC output from the smoothing capacitor as an operation power supply;
Power supply monitoring means for monitoring the power supply state of the path from the power switch to the diode bridge,
When the power switch is turned on, the switching control circuit starts to operate using a DC output generated from the smoothing capacitor by supplying power to the diode bridge as an operation power supply, and on / off control of the switching element of the converter circuit is performed. The control power is supplied to the CPU and the operation power supply is switched to supply power from the converter circuit. The CPU turns on the contactor and supplies the robot power to the robot body. Operation control is performed, and the operation control state is continued while the power supply monitoring unit detects the power supply state,
When the power switch is turned off, the CPU determines that the switch is turned off when the power feeding monitoring means detects that the power supply to the diode bridge is stopped, and operates while using the charge of the smoothing capacitor as a power source. In addition, the robot controller is configured so that the contactor is turned off after the stop control of the robot body is executed.

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