Robot system and control method for power supply circuit in robot system controller

Abstract

The robot system can be connected to a DC power source. [Solution] The robot system 10 comprises a first controller 201, which is connected to a DC power supply (DC bus 290) via a first terminal 27, and has a motor drive circuit 20 that receives DC current from the DC power supply and outputs drive signals to electric motors 31-1, ..., 31-n of a first robot 31; and a second controller 202, which is connected to the DC power supply in parallel with the first controller via a second terminal 27, and has a motor drive circuit 20 that receives DC current from the DC power supply and outputs drive signals to electric motors 32-1, ..., 32-n, 51 of a second robot 32 or a peripheral device (conveyor 50).

Description

[Technical Field]

[0001] The technology disclosed herein relates to a robot system. [Background technology]

[0002] Patent Document 1 describes a conventional robot system. The conventional robot system includes a robot arm and a robot controller. The robot arm is not a stationary type but a mobile robot arm that can be moved. The robot controller is selectively connectable to a commercial power supply, which is an AC power supply, and a battery, which is a DC power supply. More specifically, the conventional robot system includes a commercial power supply device that has an AC / DC converter and can be connected to the commercial power supply, and a rechargeable power supply device that has a rechargeable battery and a voltage regulator. The commercial power supply device or the rechargeable power supply device is connected to a connector of the robot controller. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6892080 Summary of the Invention [Problem to be solved by the invention]

[0004] DC microgrids are attracting attention from the perspectives of carbon neutrality and efficient energy utilization, and robotic systems require connection to DC power sources. [Means for solving the problem]

[0005] The technology disclosed herein relates to a robot system. a first controller connected to a DC power supply via a first terminal, the first controller having a motor drive circuit to which a DC current from the DC power supply is input and which outputs a drive signal to an electric motor of a first robot; a second controller connected in parallel to the first controller to the DC power supply via a second terminal, the second controller having a motor drive circuit to which a DC current from the DC power supply is input and which outputs a drive signal to an electric motor of a second robot or a peripheral device of the first robot; Equipped with. [Effects of the Invention]

[0006] The motor drive circuits of the first and second controllers can receive DC current from a DC power source to drive the electric motors of the first robot and the electric motors of the second robot or peripheral device. The robot system can be connected to a DC power source. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 shows a robotic system. [Figure 2] FIG. 2 shows a robot system connected to an AC power source and a robot system connected to a DC power source. [Figure 3] Figure 3 shows a robotic system with multiple controllers connected to the DC bus of a DC microgrid. [Figure 4] FIG. 4 shows an example of a robot system. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of a robot system will be described with reference to the drawings. The robot system described here is an example.

[0009] (Basic configuration of the robot system) FIG. 1 shows the basic structure of a robot system 1. The robot system 1 includes a controller 2. The controller 2 controls a robot 3. The controller 2 is a unit having a single housing 4. Note that the robot 3 is not an essential element of the robot system 1.

[0010] The robot 3 has an electric motor as a driving element. The robot 3 has a plurality of electric motors, numbered 1 to n, 3-1, ..., 3-n. The electric motors 3-1, ..., 3-n drive, for example, joints of the robot 3. The robot 3 is, for example, an articulated robot. Note that the electric motors 3-1, ..., 3-n are not limited to moving joints. Also, the robot 3 is not limited to being an articulated robot. The electric motors 3-1, ..., 3-n are, for example, three-phase AC motors, as shown in FIG. 1 . Note that the number of phases of the electric motors 3-1, ..., 3-n may be single-phase. The electric motors 3-1, ..., 3-n may also be stepping motors. The electric motors 3-1, ..., 3-n are an example of a load of the robot system 1.

[0011] The controller 2 includes a motor drive circuit 20. The motor drive circuit 20 drives the electric motors 3-1, ..., 3-n of the robot 3. The motor drive circuit 20 includes an inverter. The motor drive circuit 20 includes multiple inverters, numbered first to n, 2-1, ..., 2-n. The inverters 2-1, ..., 2-n correspond to the electric motors 3-1, ..., 3-n of the robot 3, respectively, and are connected in parallel to a DC link 26, which will be described later. The inverters 2-1, ..., 2-n each convert the DC current of the DC link 26 into AC current and output the AC current as a drive signal to the electric motors 3-1, ..., 3-n. The inverters 2-1, ..., 2-n in FIG. 1 are three-phase inverters each having a bridge circuit including multiple switching elements. Note that the inverters 2-1, ..., 2-n included in the motor drive circuit 20 are not limited to the configuration example shown in FIG. 1. Reference symbol Cs denotes a smoothing capacitor Cs connected between the positive and negative pole wires of the DC link 26.

[0012] The controller 2 includes a power supply circuit 22. The power supply circuit 22 has a function of converting AC current into DC current. The power supply circuit 22 is located between a power receiving terminal 27 (described later) and the motor drive circuit 20.

[0013] The power supply circuit 22 includes a rectifier circuit 23. The rectifier circuit 23 is a converter that converts AC current into DC current. The rectifier circuit 23 is, for example, a full-wave rectifier circuit including a diode. Note that the rectifier circuit 23 is not limited to a full-wave rectifier circuit, and is not limited to a rectifier circuit including a diode. The rectifier circuit 23 may be, for example, a PWM (Pulse Width Modulation) converter. The primary side of the rectifier circuit 23 is connected to a power receiving terminal 27. The secondary side of the rectifier circuit 23 is connected to a DC link 26. Note that in this disclosure, the term "terminal" is used to refer to a current inlet / outlet provided for connecting an electric circuit. For example, there is no intention to limit the term to a specific physical configuration such as a semiconductor lead, a terminal block, or a connector. For example, an electric wire connecting circuits or elements, or a wiring on a printed circuit board, may correspond to a terminal.

[0014] An AC power supply 28 or a DC power supply 29 is selectively connected to the power receiving terminal 27. The AC power supply 28 may be, for example, a commercial AC power supply. The AC power supply 28 may be, for example, a three-phase 400V AC power supply, a three-phase 200V AC power supply, or a three-phase 600V AC power supply. The DC power supply 29 may be, for example, a DC bus of a DC microgrid. The DC power supply 29 may also be a rechargeable battery power supply. The power receiving terminal 27 has three terminals: first, second, and third. A three-phase AC power supply can be connected to the power receiving terminal 27.

[0015] The power supply circuit 22 includes a bypass circuit 24. The bypass circuit 24 is located outside the rectifier circuit 23 and provides electrical continuity between the primary side and the secondary side of the rectifier circuit 23. The power supply circuit 22 also includes a switch 25. The switch 25 switches the bypass circuit 24 between electrical continuity and non-conduction. As will be described later, the switch 25 is a control switch that switches between on and off in response to a control signal from the control board 21.

[0016] FIG. 2 shows the robot system 1 when an AC power supply 28 is connected to the power receiving terminal 27, and the robot system 1 when a DC power supply 29 is connected to the power receiving terminal 27. When the AC power supply 28 is connected to the power receiving terminal 27, the switch 25 releases the conduction of the bypass circuit 24, as shown in the upper diagram of FIG. 2. The rectifier circuit 23 converts the input AC current into DC current and outputs it to the DC link 26. When the DC power supply 29 is connected to the power receiving terminal 27, the switch 25 releases the conduction of the bypass circuit 24, as shown in the lower diagram of FIG. 2. The DC current from the DC power supply 29 bypasses the rectifier circuit 23 and flows to the DC link 26. The rectifier circuit 23 does not convert AC current to DC current.

[0017] The controller 2 has a control board 21. The control board 21 controls the robot 3 through control of the motor drive circuit 20. The isolated power supply unit 210 supplies power to the control board 21. The isolated power supply unit 210 is connected to the DC link 26 and supplies power from the DC link 26 to the control board 21. The control board 21 is an example of a load of the robot system 1.

[0018] The control board 21 also controls the power supply circuit 22. The control board 21 detects the type of power supply connected to the power receiving terminals 27 by detecting the current and voltage on the primary side of the rectifier circuit 23. When an AC power supply 28 is connected to the power receiving terminals 27, the control board 21 outputs a control signal to turn off the switch 25. As described above, the rectifier circuit 23 converts the input AC current into DC current and outputs it to the DC link 26. When a DC power supply 29 is connected to the power receiving terminals 27, the control board 21 outputs a control signal to turn on the switch 25. As described above, the rectifier circuit 23 does not convert AC current to DC current.

[0019] The controller 2 of the robot system 1 can be connected to a DC power supply 29. The controller 2 can also be connected to an AC power supply 28. The controller 2 can control the robot 3 whether it is connected to the AC power supply 28 or the DC power supply 29. The controller 2 can be connected to various power supplies, which increases its versatility.

[0020] (Application of robotic systems to DC microgrids) 3 shows a robot system 10 applied to a DC microgrid. The robot system 10 includes a first controller 201 and a second controller 202.

[0021] The first controller 201 is connected to the first robot 31 and controls the first robot 31. The second controller 202 is connected to the second robot 32 and controls the second robot 32. The first robot 31 and the second robot 32 are separate robots independent of each other. The first robot 31 has a plurality of electric motors 31-1, ..., 31-n. The second robot 32 has a plurality of electric motors 32-1, ..., 32-n. The first robot 31 and the second robot 32 may have the same structure or different structures. The number of robots is not limited to two, and may be three or more. In other words, the number of controllers included in the robot system 10 is not limited to two, and may be three or more.

[0022] As described above, the first controller 201 is a unit having a housing 4. The second controller 202 is also a unit having a housing 4. The first controller 201 and the second controller 202 are independent of each other. However, in the robot system 10, it is not excluded that the first controller 201 and the second controller 202 communicate with each other directly or indirectly.

[0023] The first controller 201 and the second controller 202 have the same structure. The first controller 201 and the second controller 202 have substantially the same structure as the controller 2 described above.

[0024] The first controller 201 and the second controller 202 each include a control board 21, a power supply circuit 22, a power receiving terminal 27, and an insulated power supply unit 210. The power supply circuit 22 includes a rectifier circuit 23, a bypass circuit 24, and a switch 25.

[0025] The power receiving terminal 27 of the first controller 201 is connected to a DC bus 290 of the DC microgrid as a DC power source, and the power receiving terminal 27 of the second controller 202 is also connected to the DC bus 290 of the DC microgrid. The power receiving terminal 27 of the first controller 201 is an example of a first terminal, and the power receiving terminal 27 of the second controller 202 is an example of a second terminal. The first controller 201 and the second controller 202 are connected in parallel to the DC bus 290. The switch 25 of the first controller 201 is on, and the rectifier circuit 23 does not function. The switch 25 of the second controller 201 is also on, and the rectifier circuit 23 does not function.

[0026] The first controller 201 and the second controller 202 each have a motor drive circuit 20. The motor drive circuit 20 of the first controller 201 has a plurality of inverters 201-1, ..., 201-n. The motor drive circuit 20 of the second controller 202 has a plurality of inverters 202-1, ..., 202-n. The inverter 201-1 is an example of a first inverter, and the inverter 201-n is an example of a third inverter. The inverter 202-1 is an example of a second inverter.

[0027] Here, the motor drive circuit 20 including an inverter of the first controller 201 drives the electric motors 31-1, ..., 31-n of the first robot 31, and outputs regenerative DC current to the DC link 26 when the electric motors 31-1, ..., 31-n decelerate. Similarly, the motor drive circuit 20 of the second controller 202 drives the electric motors 32-1, ..., 32-n of the second robot 32, and outputs regenerative DC current to the DC link 26 when the electric motors 32-1, ..., 32-n decelerate.

[0028] The first controller 201 and the second controller 202 each have a regenerative discharge resistor 211. The regenerative discharge resistor 211 is connected to the DC link 26. The regenerative discharge resistor 211 has a function of dissipating regenerative DC current from the electric motors 31-1, ..., 31-n or 32-1, ..., 32-n of the first robot 31 or the second robot 32. The regenerative discharge resistor 211 is an example of a resistor circuit. The regenerative discharge resistor 211 dissipates the regenerative DC current when the first controller 201 or the second controller 202 is connected to the AC power supply 28. The regenerative discharge resistor 211 does not dissipate the regenerative DC current when the first controller 201 or the second controller 202 is connected to the DC power supply 29. In the first controller 201, the regenerative DC current is sent from the DC link 26 through the bypass circuit 24 to the DC bus 290, as shown by the dotted arrow in FIG. 3 . In the second controller 202, the regenerated DC current is sent from the DC link 26 through the bypass circuit 24 to the DC bus 290, as shown by the dotted arrow in FIG.

[0029] (Action and effect) The first controller 201 and the second controller 202 can be connected to a DC power supply. The first controller 201 and the second controller 202 are connected to a DC bus of a DC microgrid to configure the robot system 10. The robot system 10 is a system that can be connected to a DC power supply.

[0030] When the first controller 201 is connected to the DC power supplies 29, 290, the bypass circuit 24 is turned on and conversion by the rectifier circuit 23 is skipped. For the first controller 201, loss in the power supply circuit 22 is reduced. The first controller 201 having the bypass circuit 24 is advantageous for improving efficiency when using the DC power supplies 29, 290. The same applies to the second controller 202.

[0031] The motor drive circuit 20 of the first controller 201 is capable of driving the electric motors 31-1, ..., 31-n of the first robot 31 and outputting regenerative DC current when the electric motors 31-1, ..., 31-n decelerate. The regenerative DC current of the first controller 201 is sent to the DC bus 290 via the bypass circuit 24. The regenerative DC current of the first controller 201 can be used in the second controller 202.

[0032] Similarly, the motor drive circuit 20 of the second controller 202 is capable of driving the electric motors 32-1, ..., 32-n of the second robot 32 and outputting regenerative DC current when the electric motors 32-1, ..., 32-n decelerate. The regenerative DC current of the second controller 202 is sent to the DC bus 290 via the bypass circuit 24. The regenerative DC current of the second controller 202 can be used in the first controller 201.

[0033] The robot system 10 has excellent energy-saving performance because the regenerative DC current can be shared among the multiple controllers 201 and 202.

[0034] (Variation) The switch 25 of the controllers 2, 201, 202 is not limited to a control switch, but may be a switch that is manually switched on and off. When an AC power supply 28 is connected to the controller 2, the operator manually switches the switch 25 off, and when a DC power supply 29, 290 is connected to the controller 2, the operator manually switches the switch 25 on.

[0035] The switch 25 may be replaced with a jumper. The jumper may be a jumper switch or a jumper wire. A device having a function equivalent to the switch 25 may also be used. For example, a relay or a semiconductor switching element may be used instead of the switch.

[0036] The control board 21 may control the switch 25 of the power supply circuit 22 based on parameters other than the current and voltage on the primary side. Specifically, the control board 21 may switch the switch 25 in response to (a) a load on the secondary side, (b) the remaining amount of the battery power connected to the power supply circuit 22, or (c) a command from a higher-level terminal of the controllers 2, 201, 202, for example, via communication.

[0037] In the robot system 10 connected to the DC bus 290, the first controller 201 and the second controller 202 can omit the rectifier circuit 23, the bypass circuit 24, and the switch 35.

[0038] Even when the first controller 201 or the second controller 202 is connected to the AC power supply 28, it may be configured to send the regenerative current to the AC power supply 28. For example, if the rectifier circuit 23 is a PWM converter, the PWM converter may convert the regenerative DC current into an AC current and send it to the AC power supply 28. Furthermore, even if the rectifier circuit 23 is a rectifier circuit including a diode, a regenerative power conversion circuit may be added to the first controller 201 or the second controller 202 so that the regenerative power conversion circuit converts the regenerative DC current into an AC current and sends it to the AC power supply 28.

[0039] The controllers 2, 201, 202 are not limited to being connected to the robots 3, 31, 32 and controlling the robots 3, 31, 32, but may also be connected to the robots 3, 31, 32 and peripheral devices of the robots 3, 31, 32 and control or supply power to the robots 3, 31, 32 and peripheral devices.

[0040] 4 illustrates a specific configuration of a robot system 100 including peripheral devices. The controlled objects of the robot system 100 are industrial robots 31 and 32 and a conveyor 50. The industrial robots 31 and 32 perform work on a workpiece 5. The conveyor 50 transports the workpiece 5 to the robots 31 and 32. The conveyor 50 is an example of a peripheral device for the robots 31 and 32.

[0041] The first controller 201 is connected to the first robot 31 and controls the first robot 31. The second controller 202 is connected to the second robot 32 and controls the second robot 32. The third controller 203 is connected to the conveyor 50 and controls the electric motor 51 of the conveyor 50. The first controller 201, the second controller 202, and the third controller 203 are connected to a DC bus 290. The third controller 203 has the same structure as the first controller 201 and the second controller 202 (see FIG. 3).

[0042] The peripheral equipment is a device that works in cooperation with the robot 3 to perform a task. In addition to the conveyor 50, the peripheral equipment may include a moving device that moves the robot 3, a turntable that turns the robot 3, or a device that performs processing on the workpiece 5 transported by the robot 3, such as an aligner that aligns a substrate as the workpiece. The peripheral equipment includes a robot. A robot that transports a workpiece to the robot, for example.

[0043] Furthermore, the control target of the controllers 2, 201, 202, 203 is not limited to the industrial robot 3, but may be, for example, a social robot.

[0044] The functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, special-purpose processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuitry. In this disclosure, a circuit, unit, or means is hardware that performs the recited functions or hardware that is programmed to perform the recited functions. The hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. Where the hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or processor.

[0045] (Aspect) The above-described embodiment is a specific example of the following aspects.

[0046] (Aspect 1) a first controller (201) connected to a DC power supply (290) via a first terminal (27), the first controller (201) having a motor drive circuit (20) to which a DC current from the DC power supply (290) is input and which outputs a drive signal to an electric motor (31-1, ..., 31-n) of a first robot (31); a second controller (202, 203) connected in parallel with the first controller (201) to the DC power supply (290) via a second terminal (27), the second controller (202, 203 having a motor drive circuit (20) to which a DC current from the DC power supply (290) is input and which outputs a drive signal to an electric motor (32-1, ..., 32-n, 51) of a peripheral device (50) of the second robot (32) or the first robot (31); A robot system (10, 100) comprising:

[0047] The motor drive circuits 20 of the first and second controllers 201, 202, 203 can receive DC current from a DC power supply 290 to drive the electric motors 31-1, ... 31-n, 32-1, ... 32-n of the first and second robots 31, 32 or the electric motor 51 of the peripheral device 50. The robot system 10 can be connected to the DC power supply 290.

[0048] (Aspect 2) the motor drive circuit (20) of the first controller (201) has a first inverter (201-1) whose secondary side is connected to a first AC motor (31-1) of the first robot (31) to drive the first AC motor (31-1), and which outputs a regenerative DC current to its primary side when the first AC motor (31-1) is decelerating; the motor drive circuit (20) of the second controller (202) has a second inverter (202-1) whose secondary side is connected to a second AC motor (32-1, 51) of the second robot (32) or the peripheral device (50) and drives the second AC motor (32-1, 51), and which outputs a regenerative DC current to its primary side when the second AC motor (32-1, 51) is decelerated; A robotic system (10, 100) according to embodiment 1.

[0049] The motor drive circuit (20) of the first controller (201) receives DC power from the DC power supply (290) via a first inverter (201-1) and can drive a first AC motor (31-1) of the first robot (31). The motor drive circuit (20) of the second controller (202) receives DC power from the DC power supply (290) via a second inverter (202-1) and can drive a second AC motor (32-1, 51) of the second robot (32) or a peripheral device (50).

[0050] (Aspect 3) the motor drive circuit (20) of the first controller (201) has a third inverter (201-n) whose secondary side is connected to a third AC motor (31-n) of the first robot (31) and drives the third AC motor (31-n), and which outputs a regenerative DC current to its primary side when the third AC motor (31-n) decelerates; A robotic system (10, 100) according to embodiment 2.

[0051] The first controller (201) can control the first robot (31) using a plurality of inverters (201-1, 201-n) corresponding to a plurality of AC motors (31-1, 31-n).

[0052] (Aspect 4) The first controller (201) and the second controller (202) are each connected to a DC bus (290) of a DC microgrid as the DC power source. A robotic system (10, 100) according to aspect 2 or 3.

[0053] A robotic system (10) connected to a DC bus (290) of a DC microgrid can achieve high energy efficiency.

[0054] (Aspect 5) The regenerative DC current of the first controller (201) is sent to the DC bus (290); The regenerated DC current of the second controller (202) is sent to the DC bus (290). A robotic system (10, 100) according to embodiment 4.

[0055] The second controller (202) can utilize the regenerative DC current of the first controller (201) via the DC bus (290), and the first controller (201) can utilize the regenerative DC current of the second controller (202) via the DC bus (290), so the robot system (10) has excellent energy-saving performance.

[0056] (Aspect 6) The first terminal (27) is selectively connected to the DC power source (29, 290) or the AC power source (28), the first controller (2, 201, 202) further includes a power supply circuit (22) that converts AC current into DC current between the first terminal (27) and the motor drive circuit (20); the power supply circuit (22) performs the conversion when the AC power supply (28) is connected to the first terminal (27), and does not perform the conversion when the DC power supply (29, 290) is connected to the first terminal (27); A robot system (1, 10, 100) according to any one of aspects 1 to 5.

[0057] When an AC power supply (28) is connected to the first terminal (27), the power supply circuit (22) converts AC current to DC current. When a DC power supply (29, 290) is connected to the first terminal (27), the power supply circuit (22) does not convert AC current to DC current. The first controller (2, 201, 202) can control the first robot (31) whether it is connected to the AC power supply (28) or the DC power supply (29, 290).

[0058] (Aspect 7) the power supply circuit (22) includes a rectifier circuit (23) that converts the AC current into the DC current, and a bypass circuit (24) that bypasses the rectifier circuit (23); the bypass circuit (24) is deenergized when the AC power supply (28) is connected to the first terminal (27), and is energized when the DC power supply (29, 290) is connected to the first terminal (27); A robot system (1, 10, 100) according to embodiment 6.

[0059] When the bypass circuit (24) is deenergized, AC current from the AC power source (28) is input to the rectifier circuit (23), which converts the AC current to DC current. When the bypass circuit (24) is conductive, DC current from the DC power source (29, 290) flows through the bypass circuit (24) and bypasses the rectifier circuit (23). The rectifier circuit (23) does not convert AC current to DC current. This reduces losses in the power supply circuit (22), improving the efficiency of the controllers (2, 201, 202) when using the DC power source (29, 290).

[0060] (Aspect 8) the first controllers (201, 202) further include a resistance circuit (211) connected to a secondary side of the power supply circuit (22) and dissipating a regenerative current of the electric motors (31-1, ..., 31-n) of the first robot (31); the resistance circuit (211) dissipates a regenerative current of the electric motor (31-1, ..., 31-n) when the AC power supply (28) is connected to the first terminal (27), and does not dissipate the regenerative current when the DC power supply (29, 290) is connected to the first terminal (27); A robotic system (10, 100) according to aspect 6 or 7.

[0061] If the first controllers (201, 202) are connected to the DC power supplies (29, 290), the resistor circuit (211) prevents the regenerative current from being lost. The robot system (10) has excellent energy-saving performance because the regenerative DC current can be shared among the multiple controllers (201, 202).

[0062] If the first controllers (201, 202) are connected to an AC power supply (28) and a regenerative current is to be utilized, the regenerative current must be synchronized with the AC power supply (28). This complicates the structure of the first controllers (201, 202). However, the resistor circuit (211) dissipates the regenerative current, so the structure of the first controllers (201, 202) is simple. [Explanation of symbols]

[0063] 1. Robot System 10 Robot Systems 2 Controller 2-1, ..., 2-n inverters 20 Motor drive circuit 201 First Controller 201-1, ..., 201-n inverters 202 Second Controller 202-1, ..., 202-n inverters 211 Regenerative discharge resistor (resistance circuit) 22 Power supply circuit 23 Rectifier circuit 24 Bypass circuit 27 Power receiving terminal (1st terminal, 2nd terminal) 28 AC power supply 29 DC power supply 290 DC bus (DC power supply) 3. Robot 3-1, ..., 3-n electric motors 31 First Robot 32 Second Robot 31-1, ..., 31-n electric motors 32-1, ..., 32-n electric motors

Claims

1. a first controller connected to a DC power supply via a first terminal, the first controller having a motor drive circuit to which a DC current from the DC power supply is input and which outputs a drive signal to an electric motor of a first robot; a second controller connected in parallel to the first controller to the DC power supply via a second terminal, the second controller having a motor drive circuit to which a DC current from the DC power supply is input and which outputs a drive signal to an electric motor of a second robot or a peripheral device of the first robot; Equipped with the first terminal is selectively connected to the DC power supply or the AC power supply, the first controller further includes a power supply circuit that converts AC current into DC current between the first terminal and the motor drive circuit, and a resistance circuit that is connected to a secondary side of the power supply circuit and that dissipates regenerative current of the electric motor of the first robot; the power supply circuit performs the conversion when the AC power supply is connected to the first terminal, and does not perform the conversion when the DC power supply is connected to the first terminal; the resistance circuit dissipates a regenerative current of the electric motor when the AC power supply is connected to the first terminal, and does not dissipate the regenerative current when the DC power supply is connected to the first terminal; Robot system.

2. 2. The robot system according to claim 1, the motor drive circuit of the first controller has a first inverter whose secondary side is connected to a first AC motor of the first robot to drive the first AC motor and which outputs a regenerative DC current to its primary side when the first AC motor is decelerating; the motor drive circuit of the second controller has a second inverter whose secondary side is connected to a second AC motor of the second robot or the peripheral device, drives the second AC motor, and outputs a regenerative DC current to its primary side when the second AC motor is decelerating; Robot system.

3. 3. The robot system according to claim 2, the motor drive circuit of the first controller has a third inverter whose secondary side is connected to a third AC motor of the first robot to drive the third AC motor and which outputs a regenerative DC current to its primary side when the third AC motor is decelerating; Robot system.

4. 4. The robot system according to claim 2, The first controller and the second controller are each connected to a DC bus of a DC microgrid as the DC power source. Robot system.

5. The robot system according to claim 4, The regenerative DC current of the first controller is sent to the DC bus; The regenerated DC current of the second controller is sent to the DC bus. Robot system.

6. 2. The robot system according to claim 1, the power supply circuit includes a rectifier circuit that converts the AC current into the DC current, and a bypass circuit that bypasses the rectifier circuit; the bypass circuit is turned off when the AC power supply is connected to the first terminal, and turned on when the DC power supply is connected to the first terminal; Robot system.

7. A first controller connected to a DC power supply via a first terminal, the first controller having a motor drive circuit to which a DC current from the DC power supply is input and which outputs a drive signal to an electric motor of a first robot; a second controller connected in parallel to the first controller to the DC power supply via a second terminal, the second controller having a motor drive circuit that receives a DC current from the DC power supply and outputs a drive signal to an electric motor of a second robot or a peripheral device of the first robot, the method comprising: the first terminal is selectively connected to the DC power supply or the AC power supply, When the AC power supply is selectively connected to the first terminal, a power supply circuit of the first controller converts AC current into DC current between the first terminal and the motor drive circuit, and a resistance circuit connected to a secondary side of the power supply circuit dissipates regenerative current of the electric motor of the first robot, When the DC power supply is selectively connected to the first terminal, the power supply circuit does not perform the conversion, and the resistance circuit does not dissipate the regenerative current. A method for controlling a power supply circuit in a controller of a robot system.

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