Control method for power supply circuits in robot systems and robot system controllers

Abstract

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

Description

【Technical Field】 【0001】 The technology disclosed herein relates to a robot system. 【Background Art】 【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 a mobile robot arm that is movable rather than a stationary type. The robot controller can be selectively connected 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 power supply device for commercial power having an AC / DC converter and being connectable to the commercial power supply, and a rechargeable power supply device having a rechargeable battery and a voltage regulator. A power supply device for commercial power or a rechargeable power supply device is connected to a connector of the robot controller. 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent No. 6892080 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 DC microgrids have attracted attention from the viewpoints of carbon neutrality and efficient use of energy. A robot system is required to be connected to a DC power supply. 【Means for Solving the Problems】 【0005】 The technology disclosed herein relates to a robot system. The robot system is a controller connected to a DC power supply via a first terminal, the controller having a motor drive circuit into which the DC current of the DC power supply is input and which outputs a drive signal to an electric motor of a first robot. A controller connected in parallel with the first controller to the DC power supply via a second terminal, the second controller having a motor drive circuit that receives the DC current from the DC power supply and outputs a drive signal to the electric motor of the second robot or peripheral equipment of the first robot, It is equipped with. [Effects of the Invention] 【0006】 The motor drive circuits of the first and second controllers, respectively, can receive DC current from a DC power supply to drive the electric motor of the first robot and the electric motor of the second robot or peripheral equipment. The robot system can be connected to a DC power supply. [Brief explanation of the drawing] 【0007】 [Figure 1] Figure 1 shows the robot system. [Figure 2] Figure 2 shows a robot system connected to an AC power supply and a robot system connected to a DC power supply. [Figure 3] Figure 3 shows a robotic system in which multiple controllers are connected to the DC bus of a DC microgrid. [Figure 4] Figure 4 shows an example of a robot system. [Modes for carrying out the invention] 【0008】 The following describes an embodiment of the robot system with reference to the drawings. The robot system described here is illustrative. 【0009】 (Basic configuration of the robot system) Figure 1 shows the basic structure of robot system 1. Robot system 1 includes a controller 2. Controller 2 controls robot 3. Controller 2 is a unit with a single housing 4. Note that robot 3 is not an essential element of robot system 1. 【0010】 Robot 3 has electric motors as driving elements. Robot 3 has a plurality of electric motors 3-1, ..., 3-n from the first to the nth. Electric motors 3-1, ..., 3-n drive, for example, the joints of robot 3. Robot 3 is, for example, an articulated robot. Note that electric motors 3-1, ..., 3-n are not limited to moving joints. Also, robot 3 is not limited to an articulated robot. Electric motors 3-1, ..., 3-n are AC motors. Electric motors 3-1, ..., 3-n are, for example, three-phase AC motors as shown in Figure 1. Note that the number of phases of electric motors 3-1, ..., 3-n may be single-phase. Electric motors 3-1, ..., 3-n may also be stepping motors. Electric motors 3-1, ..., 3-n are an example of loads for robot system 1. 【0011】 Controller 2 has 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 has inverters. The motor drive circuit 20 has a plurality of inverters 2-1, ..., 2-n from the first to the nth. Each of the inverters 2-1, ..., 2-n corresponds to each of the electric motors 3-1, ..., 3-n of the robot 3, and these inverters 2-1, ..., 2-n are connected in parallel to the DC link 26, which will be described later. Each of the inverters 2-1, ..., 2-n converts the DC current of the DC link 26 into AC current, and outputs the AC current as a drive signal to the electric motors 3-1, ..., 3-n. Inverters 2-1, ..., 2-n in Figure 1 are each three-phase inverters and have a bridge circuit including multiple switching elements. Note that the inverters 2-1, ..., 2-n of the motor drive circuit 20 are not limited to the configuration example in Figure 1. The symbol Cs represents the smoothing capacitor Cs connected between the positive and negative terminal wires of the DC link 26. 【0012】 Controller 2 has a power supply circuit 22. The power supply circuit 22 has the function of converting alternating current to direct current. The power supply circuit 22 is located between the 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 alternating current to direct current. The rectifier circuit 23 is, for example, a full-wave rectifier circuit including a diode. However, the rectifier circuit 23 is not limited to a full-wave rectifier circuit, nor is it 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 the power receiving terminal 27. The secondary side of the rectifier circuit 23 is connected to the DC link 26. In this disclosure, the term "terminal" is used to refer to an input or output of current provided for the connection of an electrical circuit. For example, there is no intention to limit it to specific physical configurations such as semiconductor leads, terminal blocks, or connectors; wires connecting circuits or elements, or wiring on a printed circuit board may also be considered terminals. 【0014】 A 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. Examples of the AC power supply 28 include a three-phase AC 400V power supply, a three-phase AC 200V power supply, or a three-phase AC 600V 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: a first, a second, and a 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 connects the primary and secondary sides of the rectifier circuit 23 outside of the rectifier circuit 23. The power supply circuit 22 also includes a switch 25. The switch 25 switches the bypass circuit 24 between conducting and deconducting. 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】 Figure 2 shows the robot system 1 when the AC power supply 28 is connected to the power receiving terminal 27 and the robot system 1 when the 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, as shown in the upper diagram of Figure 2, the switch 25 releases the conduction of the bypass circuit 24. The rectifier circuit 23 converts the input AC current into a DC current and outputs it to the DC link 26. When the DC power supply 29 is connected to the power receiving terminal 27, as shown in the lower diagram of Figure 2, the switch 25 conducts the bypass circuit 24. 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 perform the conversion from AC current to DC current. 【0017】 The controller 2 has a control board 21. The control board 21 controls the robot 3 through the control of the motor drive circuit 20. The insulated power supply unit 210 supplies power to the control board 21. The insulated power supply unit 210 is connected to the DC link 26 and supplies the power of 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 terminal 27 by detecting the current and voltage on the primary side of the rectifier circuit 23. When the AC power supply 28 is connected to the power receiving terminal 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 a 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 control board 21 outputs a control signal to turn on the switch 25. As described above, the rectifier circuit 23 does not perform the conversion from AC current to DC current. 【0019】 The controller 2 of the robot system 1 can be connected to the DC power supply 29. Also, the controller 2 can be connected to the 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. Since the controller 2 can be connected to various power supplies, its versatility is enhanced. 【0020】 (Application to the DC Microgrid of the Robot System) FIG. 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 be robots with the same structure or robots with different structures. The number of robots is not limited to two and may be three or more. That is, the number of controllers included in the robot system 10 is not limited to two and may be three or more. 【0022】 The first controller 201 is a unit having the housing 4 as described above. The second controller 202 is also a unit having the 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 directly or indirectly. 【0023】 The first controller 201 and the second controller 202 have the same structure as each other. The first controller 201 and the second controller 202 are substantially the same structure as the controller 2 described above. 【0024】 Both the first controller 201 and the second controller 202 have 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 has 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 the DC bus 290 of the DC microgrid, which serves 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 in parallel with respect to the DC bus 290. The switch 25 of the first controller 201 is on, and the rectifier circuit 23 is not functioning. The switch 25 of the second controller 201 is also on, and the rectifier circuit 23 is not functioning. 【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. Inverter 201-1 is an example of a first inverter, and inverter 201-n is an example of a third inverter. Inverter 202-1 is an example of a second inverter. 【0027】 Here, the motor drive circuit 20 of the first controller 201, including the inverter, drives the electric motors 31-1, ..., 31-n of the first robot 31, and outputs a regenerative DC current to the DC link 26 when the electric motors 31-1, ..., 31-n are decelerated. 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 a regenerative DC current to the DC link 26 when the electric motors 32-1, ..., 32-n are decelerated. 【0028】 The first controller 201 and the second controller 202 have a regenerative discharge resistor 211. The regenerative discharge resistor 211 is connected to the DC link 26. The regenerative discharge resistor 211 has the function of dissipating the regenerative DC current of 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 to the DC bus 290 through the bypass circuit 24, as shown by the dotted arrow in Figure 3. In the second controller 202, the regenerative DC current is sent from the DC link 26 to the DC bus 290 via the bypass circuit 24, as shown by the dotted arrow in Figure 3. 【0029】 (Effects and Benefits) The first controller 201 and the second controller 202 can be connected to a DC power supply. The robot system 10 is configured by connecting the first controller 201 and the second controller 202 to the DC bus of a DC microgrid. 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 and 290, the bypass circuit 24 is activated and the conversion by the rectifier circuit 23 is skipped. For the first controller 201, losses in the power supply circuit 22 are reduced. The first controller 201, having the bypass circuit 24, is advantageous for improving efficiency when using the DC power supplies 29 and 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 during deceleration of the electric motors 31-1, ..., 31-n. The regenerative DC current from the first controller 201 is sent to the DC bus 290 via the bypass circuit 24. The regenerative DC current from the first controller 201 can be used by 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 during deceleration of the electric motors 32-1, ..., 32-n. The regenerative DC current from the second controller 202 is sent to the DC bus 290 via the bypass circuit 24. The regenerative DC current from the second controller 202 is available to the first controller 201. 【0033】 The robot system 10 has excellent energy-saving performance because it can share regenerative DC current among multiple controllers 201 and 202. 【0034】 (modified version) Note that the switches 25 on controllers 2, 201, and 202 are not limited to control switches, but may also be switches that can be manually switched on or off. When an AC power supply 28 is connected to controller 2, the operator manually switches switch 25 to off, and when a DC power supply 29 or 290 is connected to controller 2, the operator manually switches switch 25 to on. 【0035】 Furthermore, switch 25 may be replaced with a jumper. The jumper may be a jumper switch or a jumper wire. Alternatively, a device having a function equivalent to switch 25 may be used. For example, a relay or a semiconductor switching element can be used instead of a switch. 【0036】 The control board 21 may control the switch 25 of the power supply circuit 22 based on parameters other than the primary current and voltage. Specifically, the control board 21 may switch the switch 25 in response to (a) the load on the secondary side, (b) the remaining battery power connected to the power supply circuit 22, or (c) a command from a higher-level terminal such as controllers 2, 201, or 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 to AC current and send it to the AC power supply 28. Alternatively, 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 to AC current and sends it to the AC power supply 28. 【0039】 Controllers 2, 201, and 202 are not limited to being connected to robots 3, 31, and 32 to control them, but may also be connected to robots 3, 31, and 32 and their peripheral devices to control or power robots 3, 31, and 32 and their peripheral devices. 【0040】 Figure 4 illustrates a specific configuration of the robot system 100, including peripheral equipment. The robot system 100 controls industrial robots 31 and 32 and a conveyor 50. The industrial robots 31 and 32 perform operations on the workpiece 5. The conveyor 50 transports the workpiece 5 to the robots 31 and 32. The conveyor 50 is an example of peripheral equipment for the robots 31 and 32. 【0041】 The first controller 201 is connected to and controls the first robot 31. The second controller 202 is connected to 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 the DC bus 290. The third controller 203 has the same structure as the first controller 201 and the second controller 202 (see Figure 3). 【0042】 Peripheral devices are devices that work in cooperation with robot 3 to perform tasks. In addition to the conveyor 50, peripheral devices include a moving device for moving robot 3, a turntable for rotating robot 3, or a device that performs processing on the workpiece 5 transported by robot 3, such as an aligner that aligns the substrate as a workpiece. Peripheral devices also include robots. A robot as a peripheral device is, for example, a robot that transports workpieces to the robot. 【0043】 Furthermore, the objects controlled by controllers 2, 201, 202, and 203 are not limited to the industrial robot 3, but may be, for example, social robots. 【0044】 The functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, dedicated 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 circuits. In this disclosure, a circuit, unit, or means is hardware that performs the enumerated functions, or hardware programmed to perform the enumerated functions. The hardware may be hardware disclosed herein, or other known hardware that is programmed or configured to perform the enumerated functions. If the hardware is a processor, which is considered a type of circuit, then the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or the processor. 【0045】 (Appearance) The embodiments described above are specific examples of the following embodiments. 【0046】 (Aspect 1) A 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 the DC current of the DC power supply (290) is input and which outputs drive signals to the electric motors (31-1, ..., 31-n) of the first robot (31), Controllers (202, 203) connected in parallel with the first controller (201) to the DC power supply (290) via a second terminal (27), the second controllers (202, 203) having a motor drive circuit (20) to which the DC current of the DC power supply (290) is input and which outputs a drive signal to the electric motors (32-1, ..., 32-n, 51) of the second robot (32) or peripheral equipment (50) of the first robot (31), A robotic system (10, 100) equipped with [the specified features]. 【0047】 The motor drive circuits (20) of the first and second controllers (201, 202, 203) receive DC current from a DC power supply (290) and can 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 equipment (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 the first AC motor (31-1) of the first robot (31) and drives the first AC motor (31-1), and outputs a regenerative DC current to the primary side when the first AC motor (31-1) is decelerated. The motor drive circuit (20) of the second controller (202) has a second inverter (202-1) whose secondary side is connected to the second AC motor (32-1, 51) of the second robot (32) or the peripheral device (50), and which drives the second AC motor (32-1, 51), and which outputs a regenerative DC current to the primary side when the second AC motor (32-1, 51) is decelerated. The robot system (10, 100) described in Embodiment 1. 【0049】 The motor drive circuit (20) of the first controller (201) can drive the first AC motor (31-1) of the first robot (31) by receiving DC power from a DC power supply (290) via the first inverter (201-1). The motor drive circuit (20) of the second controller (202) can drive the second AC motors (32-1, 51) of the second robot (32) or peripheral equipment (50) by receiving DC power from a DC power supply (290) via the second inverter (202-1). 【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 the third AC motor (31-n) of the first robot (31) and drives the third AC motor (31-n), and outputs a regenerative DC current to the primary side when the third AC motor (31-n) is decelerated. The robot system (10, 100) described in Embodiment 2. 【0051】 The first controller (201) can control the first robot (31) using multiple inverters (201-1, 201-n) corresponding to multiple AC motors (31-1, 31-n). 【0052】 (Aspect 4) The first controller (201) and the second controller (202) are each connected to the DC bus (290) of the DC microgrid, which serves as the DC power supply. A robotic system (10, 100) according to embodiment 2 or 3. 【0053】 A robotic system (10) connected to the DC bus (290) of a DC microgrid can achieve high energy efficiency. 【0054】 (Aspect 5) The regenerative DC current from the first controller (201) is sent to the DC bus (290). The regenerative DC current from the second controller (202) is sent to the DC bus (290). The robot system (10, 100) described in 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 either the DC power supply (29, 290) or the AC power supply (28). The first controller (2, 201, 202) further includes a power supply circuit (22) that converts alternating current to direct 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 embodiments 1 to 5. 【0057】 When an AC power supply (28) is connected to the first terminal (27), the power supply circuit (22) converts the 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 the AC current to DC current. The first controllers (2, 201, 202) can control the first robot (31) whether they are connected to an AC power supply (28) or a DC power supply (29, 290). 【0058】 (Aspect 7) The power supply circuit (22) includes a rectifier circuit (23) that converts the alternating current to the direct current, and a bypass circuit (24) that bypasses the rectifier circuit (23). The bypass circuit (24) is deactivated when the AC power supply (28) is connected to the first terminal (27), and is activated when the DC power supply (29, 290) is connected to the first terminal (27). The robot system (1, 10, 100) described in Embodiment 6. 【0059】 When the bypass circuit (24) is de-energized, AC current from the AC power supply (28) is input to the rectifier circuit (23), and the rectifier circuit (23) converts the AC current to DC current. When the bypass circuit (24) is energized, DC current from the DC power supplies (29, 290) flows through the bypass circuit (24) and bypasses the rectifier circuit (23). The rectifier circuit (23) does not perform the conversion from AC current to DC current. Since losses in the power supply circuit (22) are reduced, the efficiency of the controllers (2, 201, 202) is improved when using DC power supplies (29, 290). 【0060】 (Pattern 8) The first controllers (201, 202) are connected to the secondary side of the power supply circuit (22) and further include a resistor circuit (211) that eliminates the regenerative current of the electric motors (31-1, ..., 31-n) of the first robot (31). The resistor circuit (211) eliminates the 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 eliminate the regenerative current when the DC power supply (29, 290) is connected to the first terminal (27). A robotic system (10, 100) according to embodiment 6 or 7. 【0061】 If the first controllers (201, 202) are connected to the DC power supply (29, 290), the resistor circuit (211) does not cause the regenerative current to disappear. The robot system (10) has excellent energy-saving performance because the regenerative DC current can be shared among multiple controllers (201, 202). 【0062】 If the first controllers (201, 202) are connected to an AC power supply (28) and 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). The resistor circuit (211) eliminates 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 Controllers 2-1, ..., 2-n Inverter 20 Motor drive circuit 201 First Controller 201-1, ..., 201-n Inverter 202 Second Controller 202-1, ..., 202-n Inverter 211 Regenerative discharge resistor (resistor circuit) 22 Power circuit 23 Rectifier circuit 24 Bypass Circuit 27 Power receiving terminals (Terminal 1, Terminal 2) 28 AC power supply 29 DC power supply 290 DC bus (DC power supply) 3 Robots 3-1, ..., 3-n Electric motor 31. Robot No. 1 32. Second Robot 31-1, ..., 31-n Electric motor 32-1, ..., 32-n Electric motors

Claims

[Claim 1] A controller connected to a DC power supply via a first terminal, the first controller having a motor drive circuit that receives the DC current from the DC power supply and outputs a drive signal to the electric motor of the first robot, A controller connected in parallel with the first controller to the DC power supply via a second terminal, the second controller having a motor drive circuit that receives the DC current from the DC power supply and outputs a drive signal to the electric motor of the second robot or peripheral equipment of the first robot, A robotic system equipped with [the following features]. [Claim 2] In 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 the first AC motor of the first robot and drives the first AC motor, and which outputs a regenerative DC current to the primary side when the first AC motor is decelerated. The motor drive circuit of the second controller has a second inverter whose secondary side is connected to the second AC motor of the second robot or the peripheral device and drives the second AC motor, and which outputs a regenerative DC current to the primary side when the second AC motor is decelerated. Robot system. [Claim 3] In 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 the third AC motor of the first robot and drives the third AC motor, and which outputs a regenerative DC current to the primary side when the third AC motor is decelerated. Robot system. [Claim 4] In the robot system according to claim 2 or 3, The first controller and the second controller are each connected to the DC bus of the DC microgrid, which serves as the DC power supply. Robot system. [Claim 5] In the robot system according to claim 4, The regenerative DC current from the first controller is sent to the DC bus. The regenerative DC current from the second controller is sent to the DC bus. Robot system. [Claim 6] In the robot system according to claim 1, The first terminal is selectively connected to either the DC power supply or the AC power supply. The first controller further includes a power supply circuit that converts AC current to DC current between the first terminal and the motor drive circuit. 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. Robot system. [Claim 7] In the robot system according to claim 6, The power supply circuit includes a rectifier circuit that converts the alternating current to the direct current, and a bypass circuit that bypasses the rectifier circuit. The bypass circuit disables conduction when the AC power supply is connected to the first terminal, and enables conduction when the DC power supply is connected to the first terminal. Robot system. [Claim 8] In the robot system according to claim 6 or 7, The first controller is connected to the secondary side of the power supply circuit and further includes a resistor circuit that eliminates the regenerative current of the electric motor of the first robot. The resistor circuit, when the AC power supply is connected to the first terminal, eliminates the regenerative current of the electric motor, and when the DC power supply is connected to the first terminal, does not eliminate the regenerative current. Robot system.

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