Robot, robot control method, article manufacturing method using robot, control program, and recording medium

Abstract

To reduce a possibility of size increase of a robot.SOLUTION: A robot has at least two joints and the joints include a first joint and a second joint. A first drive source is provided at the first joint and a second drive source is provided at the second joint. Sizes of drive substrates which drive the first drive source and the second drive source are respectively changed. The robot is adopted.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a robot.

Background Art

[0002] In recent years, robots having a plurality of links that operate by a plurality of joints have attracted attention. By operating the plurality of links and manipulating parts with an end effector disposed at the tip of the robot and introducing it into a production factory, automation of the production factory is attempted. In each joint portion of the robot as described above, a drive source such as a motor for driving the link is disposed. In the technique described in Patent Document 1, a distributed control type robot system is described in which a control board for individually controlling a plurality of drive sources and a drive board for supplying power to the drive sources are disposed in the joints. By performing distributed control, the concentration of load on one control device is reduced, and improvement in controllability is achieved.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In typical robots, the output of the drive source tends to be greater for joints closer to the robot's base (root side) and smaller for joints closer to the robot's end (end-effector side). This is because the joints closer to the base need to support and operate multiple links together, while the joints closer to the end (end-effector side) are designed to perform delicate tasks while reducing the load on the base. However, the technology described in Patent Document 1 uses a drive board of the same size for each joint, and no consideration was given to drive boards that match the output of each joint in the robot. Therefore, it is possible that drive boards larger than necessary may be installed in the drive sources of the joints, potentially leading to an increase in the size of the robot.

[0005] In light of the above issues, the present invention reduces the possibility of increasing the size of the robot. [Means for solving the problem]

[0006] To solve the above problems, the present invention employs a robot having at least two joints, wherein the joints include a first joint and a second joint, the first joint is provided with a first drive source, the second joint is provided with a second drive source, and the size of the drive boards that drive the first drive source and the second drive source are changed. [Effects of the Invention]

[0007] According to the present invention, the possibility of increasing the size of the robot can be reduced. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of the robot system 1000 in an embodiment. [Figure 2] This is a control block diagram of the robot system 1000 in an embodiment. [Figure 3]This diagram shows the details of the control blocks for the motor control board 241 and the motor drive boards 251-256. [Figure 4] This figure shows the board configuration of the motor control board 241 and motor drive boards 251-256 in the embodiment. [Figure 5] This is a detailed diagram of the link shapes of the robot arm body 200 in the embodiment. [Figure 6] This diagram shows the arrangement of the motor control board 241 and the motor drive boards 251, 252, and 256 in the embodiment. [Figure 7] This figure shows the board configuration of the motor control board 241 and motor drive boards 251-256 in the embodiment. [Figure 8] This figure shows the board configuration of the motor control board 241 and motor drive boards 251-256 in the embodiment. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments for carrying out the present invention will be described with reference to the examples shown in the attached drawings.

[0010] The embodiments shown below are merely examples, and those skilled in the art can modify the details of the configuration as appropriate without departing from the spirit of the present invention. Furthermore, the numerical values ​​used in these embodiments are for reference only and do not limit the present invention. In the following drawings, the arrows X, Y, and Z indicate the overall coordinate system of the robot system. Generally, the XYZ 3D coordinate system represents the world coordinate system of the entire installation environment. In addition, a local coordinate system may be used for the robot hand, fingers, joints, etc., depending on control considerations.

[0011] (First embodiment) Figure 1 shows a schematic configuration of the robot system 1000 of this embodiment. In Figure 1, the robot system 1000 includes a robot arm body 200 configured as a multi-joint robot, a control device 300 that controls the robot arm body 200, and an external input device 400. The control device 300 includes a power supply unit 350 and a robot controller (higher-level control device) 340.

[0012] The robot arm body 200 of this embodiment is composed of a 6-axis articulated robot. The robot arm body 200 consists of a base 210 and six links 201 to 206. Each link 201 to 206 is rotationally driven by six drive units 231 to 236, which rotate each joint axis A1 to A6 around the arrows shown in the diagram. Each drive unit 231 to 236 is equipped with a motor and a reduction gear that reduces the output of the motor. In this embodiment, a harmonic drive gear reduction gear is used. That is, the motors provided in the drive units 231 to 236 are drive sources that generate driving force to displace each link 201 to 206 that each joint connects to. Each motor also has an encoder 211 to 216 built in to detect the rotation angle of the motor itself.

[0013] Torque sensors 221 to 226, which detect force information, are provided between the output terminals of the drive units 231 to 236 and the links 201 to 206 that rotate with the output terminals. Each torque sensor 221 to 226 is equipped with a structure and an optical encoder that detects the relative movement of the structure. When the joints of the robot arm body 200 are driven, the relative movement of the structures of the torque sensors 221 to 226, which is caused by the relative displacement of the links of the robot arm body 200, is detected by the optical encoder. Furthermore, there are motor drive boards 251 to 256 that drive each motor of each drive unit 231 to 236, and a motor control board 241 that controls the motors. Based on the input torque command value, the motor control board 241 outputs a current command to each motor via the drive boards 251 to 256 so that the torque detected by the torque sensors 221 to 226 at each joint follows the command value, thereby controlling the operation of each motor.

[0014] As shown in the figure, link 201 of the robot arm body 200 is connected to the base 210 by a drive unit 231 shown in the figure using a bearing (not shown) so that it can rotate together with the torque sensor 221. The drive unit 231 is assumed to have a range of motion in the direction of the arrow from the initial position. Link 202 of the robot arm body 200 is connected to link 201 by a drive unit 232 shown in the figure using a bearing (not shown) so that it can rotate together with the torque sensor 222. The drive unit 232 is assumed to have a range of motion in the direction of the arrow from the initial position.

[0015] Link 203 of the robot arm body 200 is connected to link 202 by a drive unit 233 (shown in the figure) using a bearing (not shown) so that it can rotate together with the torque sensor 223. The drive unit 233 has a range of motion in the direction of the arrow from the initial position. Link 204 of the robot arm body 200 is connected to link 203 by a drive unit 234 (shown in the figure) using a bearing (not shown) so that it can rotate together with the torque sensor 224. The drive unit 234 has a range of motion in the direction of the arrow from the initial position.

[0016] Link 205 of the robot arm body 200 is connected to link 204 by a drive unit 235 (shown in the figure) using a bearing (not shown) so that it can rotate together with the torque sensor 225. The drive unit 235 has a range of motion in the direction of the arrow from the initial position. Link 206 of the robot arm body 200 is connected to link 205 by a drive unit 236 (shown in the figure) using a bearing (not shown) so that it can rotate together with the torque sensor 226. The drive unit 235 has a range of motion in the direction of the arrow from the initial position.

[0017] Also, it is assumed that an end effector body such as an (electric) hand or a pneumatically driven air hand for performing assembly work or transfer work on the production line is connected to the tip of the link 206 of the robot arm main body 200. This end effector body is attached to the link 206 which is a predetermined part of the robot arm main body 200 by (semi) fixed means such as screwing (not shown). Alternatively, it is assumed that it can be attached by detachable means such as latch (ratchet) fixing (not shown). In particular, when the end effector body is detachable, a method of controlling the robot arm main body 200 to attach or replace the end effector body arranged at the supply position (not shown) by the operation of the robot arm main body 200 itself is also conceivable.

[0018] Here, in this embodiment, the end of the robot arm main body 200 refers to the link 206 and / or the end effector body. When the end effector body is holding an object, it refers to the end of the robot arm main body 200 including the end effector body and the object being held (such as parts or tools). That is, regardless of whether the end effector body is holding an object or not, the link 206 and / or the end effector body is referred to as the end.

[0019] The external input device 400 is provided with an operation unit including, for example, the posture (position and angle) of the joints of the robot arm main body 200 or operation keys for moving the end of the robot arm main body 200. When an operation is performed on the operation unit of the external input device 400, the control device 300 transmits a signal to the drive devices 231 to 236 of each joint according to the operation of the external input device 400, and controls the operation of the robot arm main body 200. At that time, by executing a robot control program including a control program described later, the control device 300 controls each part of the robot arm main body 200.

[0020] With the above configuration, the robot arm body 200 can move the link 206 and / or the end effector body to any position, allowing it to perform desired tasks. For example, by using a predetermined workpiece and other workpieces as materials and performing a process to assemble the predetermined workpiece and other workpieces, an assembled workpiece can be manufactured as a deliverable. Thus, the robot arm body 200 can be used to manufacture articles.

[0021] Figure 2 is a block diagram showing the schematic configuration of the control system of the robot system 1000 shown in Figure 1. The control device 300 has a robot controller 340 composed of a computer and is equipped with a CPU (Central Processing Unit) 301 as a processor. It also has a memory unit consisting of a ROM (Read Only Memory) 302, a RAM (Random Access Memory) 303, an HDD (Hard Disk Drive) 304, and a recording disk drive 305. It also has interfaces 306, 307, 308, 309, 310, and 311 for communication with each device. The CPU 301, ROM 302, RAM 303, and interfaces 306 to 309 are connected to each other by a bus 311 so that they can communicate with one another.

[0022] Of these, RAM 303 is used for temporary storage of data such as teaching points and control commands obtained from the operation of the external input device 400. ROM 302 stores basic programs 330, such as the BIOS, which allows the CPU 301 to execute various arithmetic processes. The CPU 301 executes various arithmetic processes based on the control programs recorded (stored) in HDD 304. HDD 304 is a storage unit that stores various data, etc., which are the results of the CPU 301's arithmetic processes. The recording disk drive 305 can read various data and control programs, etc., recorded on the recording disk 331. Furthermore, interfaces 307 and 308 are connected to a monitor 411 that displays various images, and external storage devices 412 such as rewritable non-volatile memory and an external HDD.

[0023] The external input device 400 could be, for example, an operating device such as a teaching pendant (TP), but it could also be another computer device (PC or server) capable of editing the robot program. The external input device 400 can be connected to the control device 300 via wired or wireless communication means and has user interface functions such as robot operation and status display. The target joint angles of each joint input by the external input device 400 are output to the CPU 301 via interface 306 and bus 311.

[0024] The CPU 301 receives teaching point data input from, for example, an external input device 400 via interface 306. It can also generate trajectories for each axis of the robot arm body 200 based on the teaching point data input from the external input device 400 and transmit them to the drive units 231-236 via interface 309 using the arm motor driver 230. The CPU 301 outputs drive command data indicating the control amount of the rotation angle of each drive unit 231-236 motor to the arm motor driver 230 via bus 311 and interface 309 at predetermined intervals.

[0025] The motor control board 241 calculates the amount of current output to the motors of each drive unit 231-236 based on the drive command input from the CPU 301, and supplies current to each motor using the motor drive boards 251-256 to control the joint angle of each joint. It also outputs detection signals from each encoder 211-216 and torque sensors 221-226 to the CPU 301 via the interface 309 and bus 311. In other words, the CPU 301 performs feedback control of the motors of each drive unit 231-236 via the motor control board 241 so that the current joint angle value of the joint detected by each encoder 211-216 becomes the target joint angle. Similarly, it performs feedback control of each motor so that the current torque value of the joint detected by each torque sensor 221-226 becomes the target torque.

[0026] Furthermore, by returning the outputs of the torque sensors 221-226 to the control device 300 and feeding them back to the drive of each drive unit 231-236, the torque applied to each link 201-206 during drive can be controlled. In addition, the force generated at the link 206 of the robot arm body 200 can be calculated from the values ​​of each torque sensor 221-226, making it possible to feedback control the load applied to the parts being assembled.

[0027] The control device 300 may also be connected to a hand motor (not shown) via an interface and a hand motor driver when a robot hand body is used as an end effector (not shown). The hand motor driver calculates the amount of current output to the hand motor based on the drive command input from the CPU 301, supplies current to the hand motor, and controls the speed of the hand motor. It also outputs pulse signals from the hand motor encoder to the CPU 301 via the interface and bus. In other words, the CPU 301 performs feedback control of the hand motor via the hand motor driver so that the current value of the hand motor speed detected by the encoder becomes the target speed.

[0028] Figure 3 shows the details of the control blocks of the motor control board 241 and motor drive boards 251-256 in this embodiment. In Figure 3, the motor control board 241 and the corresponding motor drive boards 251-256 are shown together as a single block. The components provided on the motor control board 241 and the components provided on each motor drive board 251-256 will be described later using Figure 4. The ratio of the number of motor control boards 241 to drive boards 251-256 is 1:1. In other words, the motor control board 241 uses a board with the same specifications for each joint, while the motor drive boards 251-256 have different specifications according to the electrical output of the motor in each joint. The motor control board 241 has a communication driver 103 and a control circuit 105 mounted on it. The motor drive boards 251-256 have a power supply circuit 104, an inverter 106, a power connector 119, and a communication connector 120 mounted on them. The motor drive boards 251-256 and the motor control board 241 are electrically connected by, for example, inter-board connectors, cables, flexible flat cables, etc.

[0029] The robot controller 340 is daisy-chained with each motor control board 241 via a serial communication line 130. The robot controller 340 performs distributed control, controlling each motor of each drive unit 231 to 236 by transmitting commands to the motor control boards 241. The robot controller 340 calculates the trajectory of the robot arm body 200 in order to realize the movements taught by the external input device 400. The robot controller 340 transmits various commands to each motor control board 241, such as motion commands (specifically, position commands) that instruct the operation of each rotary motor based on the trajectory calculation results, motion execution start commands that instruct the start of execution of movements based on motion commands, and synchronization commands.

[0030] The power supply unit 350 supplies power to each motor control board 241 and each motor drive board 251-256 (motor drive boards 253-255 are omitted and therefore not shown) via power cables 140. The motor drive boards 251-26, having received power, supply power to each motor of the drive unit 231-236 based on instructions from the motor control board 241, thereby driving the motors.

[0031] Each motor control board 241 and motor drive boards 251-256 are connected to the robot controller 340 via a serial communication line 130 and a communication connector 120. The communication connector 120 functions as a communication interface. Various commands are transmitted as signals to each motor control board 241 via serial communication using communication protocols such as CAN through the serial communication line 130. In addition, status notifications and other communications are transmitted and received between the robot controller 340 and each motor control board 241 via the serial communication line 130.

[0032] Each motor control board 241 is equipped with a communication driver 103 that receives signals indicating various commands from the robot controller 340, and the motor drive boards 251 to 256 are equipped with a power supply circuit 104 that converts the voltage applied by the power supply unit 350 into a predetermined DC voltage. The power supply unit 350 is connected by a power cable 140 and a power connector 119. The power connector 119 functions as a power IF.

[0033] The control circuit 105 of each motor control board 241 is composed of a microcomputer and has multiple switching elements. The control circuit 105 includes an arithmetic unit 111, a communication control unit 112, a memory 113, a clock generation unit 114, a timer 115, a PWM waveform generation unit 116, an AD conversion unit 117, and a counter 118. In this embodiment, the motor is driven by the PWM waveform generation unit 116 and the inverter 106.

[0034] Furthermore, it is equipped with a current detection unit 107 that detects the current flowing from the inverter 106 to the motor of the drive unit 231 (specifically, the motor windings). The current detection unit 107 outputs a current value indicating the current detection result as a voltage. In other words, the current detection unit 107 outputs a voltage with a voltage value proportional to or corresponding to the current value.

[0035] Furthermore, the counter 118 acquires the detection result of the encoder 211, which detects the rotational position of the motor of the drive unit 231, specifically the rotational position (in other words, the rotation angle) of the motor's rotor. The encoder 211 is, for example, a rotary encoder, which outputs pulses as the rotor rotates. The counter 118 counts the number of pulses output by the encoder 211. The counter 118 then outputs the count result to the calculation unit 111 as motor rotational position information (hereinafter simply referred to as position information). In this way, the counter 118 detects the rotational position of the motor by counting the number of pulses from the encoder 211. For the sake of simplicity, although not shown in Figure 3, it is assumed that a separate counter is also provided to acquire the detection result of the torque sensor 221.

[0036] The communication control unit 112 controls the storage of data of various commands received from the communication driver 103 in the memory 113. The memory 113 is a storage unit such as RAM, and under the control of the communication control unit 112, it stores the data of various commands received. The clock generation unit 114 is, for example, a crystal oscillator, and generates and outputs a clock signal at a specific oscillation frequency. The timer 115 measures time based on the clock signal generated by the clock generation unit 114 and outputs the measurement result to the calculation unit 111.

[0037] The calculation unit 111 is, for example, a CPU, and performs calculations according to a processing program stored in a non-volatile memory (not shown) based on various commands from the robot controller 340, current information indicating the current detection result, and position information indicating the position detection result. As one of its calculation processes, the calculation unit 111 calculates a drive command to be output to the PWM waveform generation unit 116. Then, when the calculation of this drive command is completed, the calculation unit 111 outputs the drive command to the PWM waveform generation unit 116.

[0038] The PWM waveform generation unit 116 receives a drive command input from the calculation unit 111 and generates a PWM signal to be output to the gate terminal (base terminal) of each switching element of the inverter 106. The inverter 106 pulse-width modulated the supplied DC voltage by the switching operation of the switching elements due to the PWM signal and outputs it to the motor of the drive device 231. As a result, an AC current, for example a three-phase AC current, is output to the motor of the drive device 231. Through the operation of the PWM waveform generation unit 116 and the inverter 106 as described above, the motor of the drive device 231 is driven according to the drive command that has been input. In other words, the PWM waveform generation unit 116 and the inverter 106 supply current to the motor of the drive device 231 in accordance with the drive command that has been input.

[0039] The AD conversion unit 117 converts the output voltage (analog signal) indicating the current value from the current detection unit 107 into a digital signal that can be recognized by the calculation unit 111, and outputs the current information converted into a digital signal to the calculation unit 111. The calculation unit 111 monitors the behavior of the robot arm body 200, that is, the rotational position and current of the motor of the drive unit 231, and controls the drive of the motor of the drive unit 231 by performing feedback control based on commands received from the robot controller 340. Specifically, the calculation unit 111 performs calculation processing to calculate drive commands that control the position, speed, and current (torque) of the motor in position, speed, and current control processing, based on the current information from the current detection unit 107 and the position information acquired by the encoder 211.

[0040] Figure 4 shows the board configuration of the motor control board 241 and motor drive boards 251-256 in this embodiment. For simplicity of explanation, Figure 4 shows the motor drive board 251 as an example. The other motor drive boards are also assumed to be connected to the motor control board 241 as described below. Figure 4(a) is a perspective view of the motor drive board 251. Figure 4(b) is a perspective view of the motor control board 241. Figure 4(c) is a perspective view of the motor drive board 251 and the control board 241 combined into a two-piece set, one above the other.

[0041] As shown in Figure 4(a), the motor drive board 251 includes an inverter 106, a power supply circuit 104, a power connector 119, a communication connector 120, a motor drive power connector 121, and an inter-board connector 122. The power connector 119 and the communication connector 120 are electrically connected to the robot controller (higher-level control device) 340, the power supply unit 350, or the boards of other joints via a power cable 140 and a serial communication line 130. The motor drive power connector 121 is connected to the motor of the drive unit 231 via a cable and supplies motor drive power output from the inverter 106. In Figure 4(a) of this embodiment, the power connector 119 and the communication connector 120 are configured as separate components, but they may be configured as the same connector.

[0042] As shown in Figure 4(b), the motor control board 241 includes a communication driver 103, a control circuit 105 composed of a microcomputer, a position detection connector 123, and an inter-board connector 122. In Figure 4(b), the inter-board connector 122 is assumed to be located on the back side of the motor control board 241. The position detection connector 123 is electrically connected to the encoder 211 located on the motor of the drive unit 231. In this embodiment, the communication connector 120 may be referred to as the first connector, the power connector 119 as the second connector, the motor drive power connector 121 as the third connector, and the position detection connector 123 as the fourth connector.

[0043] As shown in Figure 4(c), the motor drive board 251 and the motor control board 241 are electrically connected via the inter-board connector 122, and power supply for each electronic component and communication of various commands (control signals) are performed between the motor drive board 251 and the motor control board 241. Metal spacers (supports) 124 are placed at the four corners between the motor drive board 251 and the motor control board 241. This increases the contact area of ​​the GNDs of both boards and lowers the impedance, thereby improving noise immunity. In addition, the heat generated on the motor drive board 251 when the motor of the drive device 231 is driven can be dissipated by using the metal (high thermal conductivity) spacers 124. This makes it possible to reduce the heat dissipation pattern (solid GND) on the motor drive board 251, and thus the motor drive board 251 can be made smaller.

[0044] Furthermore, in Figure 4(c), the motor control board 241 is positioned on the motor drive board 251, covering the power supply circuit 104 and inverter 106 of the motor drive board 251, while allowing access to each connector of the motor drive board. This makes it difficult for users to access parts that pose a risk of electric shock, such as the power supply circuit 104 and inverter 106, when the motor control board 241 and motor drive board 251 are installed on the robot arm body 200, for maintenance purposes. In addition, the connectors on the motor drive board 251, which require the user to plug and unplug cables, are easily accessible. This ensures user safety during maintenance while also providing convenience during maintenance.

[0045] In Figure 4, the position detection connector 123 is located on the motor control board 241, but it can also be located on the motor drive board 251. By placing it on the motor drive board 251, the placement of each connector can be changed for each joint, allowing each cable to be routed along the shortest possible path and designed with the optimal routing at each joint of the robot arm body 200. This makes it possible to reduce the overall size of the robot arm body 200. Furthermore, the motor drive board may be configured with individually optimized electrical components according to the motor specifications and operating current, or conversely, all joints may be configured with the same electrical components.

[0046] Next, we will describe in detail how to change the board design of the motor drive board according to the operating current of each motor located in each drive unit 231 to 236 of the robot arm body 200, and how to arrange it on the robot arm body 200. Figure 5 is a detailed diagram of the link shapes of the robot arm body 200 in this embodiment. From the figure, link 201 of the robot arm body 200 rotates with respect to the base 210 around axis A1 as the axis of rotation. Link 202 of the robot arm body 200 rotates with respect to link 201 around axis A2 as the axis of rotation. Link 203 of the robot arm body 200 rotates with respect to link 202 around axis A3 as the axis of rotation. The drive unit 233 is assumed to have a range of motion in the direction of the arrow from the initial position. Link 204 of the robot arm body 200 rotates with respect to link 203 around axis A4 as the axis of rotation. Link 205 of the robot arm body 200 rotates with respect to link 204 around axis A5 as the axis of rotation. Link 206 of the robot arm body 200 rotates relative to link 205 with axis A6 as the axis of rotation.

[0047] The drive unit, motor drive board, motor control board, etc., installed inside the robot arm body 200 are the same as those described above. In this embodiment, the joint and motor that make the base 210 and link 201 rotatable may be referred to as the first joint and first drive source. The joint and motor that make link 205 and link 206 rotatable may be referred to as the second joint and second drive source. The joint and motor that make link 201 and link 202 rotatable may be referred to as the third joint and third drive source.

[0048] Figure 6 shows the arrangement of the motor control board 241 and motor drive boards 251, 252, and 256 in this embodiment. Figure 6(a) shows the motor control board 241 and motor drive board 251 arranged on the base 210. Figure 6(b) shows the motor control board 241 and motor drive board 252 arranged on link 202. Figure 6(c) shows the motor control board 241 and motor drive board 256 arranged on link 205. For the sake of simplicity in this explanation, motor drive boards 251, 252, and 256 will be used as examples, and motor drive boards 253, 254, and 255 will be assumed to have the same size design as motor drive board 252.

[0049] As shown in Figure 6(a), the motor drive board 251 on the base 210 drives the motor of the drive unit 231 that operates the link 201, which is the root end of the robot arm body 200, and therefore has a large operating current. For this reason, the motor drive board 251 is the largest in size compared to the other motor drive boards. As shown in Figure 6(b), the motor drive board 252 on the link 202 drives the motor of the drive unit 232 that operates the link 202, which is the middle part of the robot arm body 200. For this reason, the size of the motor drive board 252 is slightly smaller than that of the motor drive board 251. As shown in Figure 6(c), the motor drive board 256 on the link 205 drives the motor of the drive unit 236 that operates the link 206, which is the end-effector end of the robot arm body 200, and therefore has a small operating current. For this reason, the motor drive board 256 is the smallest in size compared to the other motor drive boards.

[0050] As described above, according to this embodiment, the motor drive boards 251 to 256 can be designed with an optimal board size for each joint according to the operating current of each motor in each drive unit 231 to 236. Because such motor drive boards are placed near the motors that move each joint to take into account the effects of noise, the placement space in the robot arm configuration may be narrow, and the board size (area) may be severely limited. However, as in this embodiment, by enabling the design of a board with an optimal board size for each joint according to the operating current of each motor, it is possible to overcome the constraints of the robot arm configuration while also reducing the size of the board. Therefore, the possibility of increasing the size of the robot can be reduced.

[0051] Furthermore, in this embodiment, the motor control board that controls the motor and the drive board that drives the motor are separated. In a distributed control system, each joint's board is equipped with a motor drive unit, a control unit that controls the motor drive unit, a power supply circuit, a robot controller (higher-level control device), and a communication interface with each joint's board, resulting in a large number of electrical components and an increased board footprint. However, by separating the motor control board that controls the motor and the drive board that drives the motor, as in this embodiment, it becomes possible to arrange the boards vertically as shown in Figure 4(c), thereby reducing the board footprint.

[0052] Furthermore, by mounting the power supply circuit 104 on the motor drive boards 251-256, they can be individually optimized for the specifications of each motor and inverter 106 of the drive units 231-236, making it possible to use a common motor control board 241 across all joints. By using a common motor control board 241, the unit cost of manufacturing the motor control board 241 is reduced, thereby lowering the cost of the robot arm body 200. Moreover, even when developing robot arms for different applications (for example, different work targets, different weights of transported objects, or where reduced production speed is required), the motor control board can be reused simply by modifying the motor drive board to suit the application. This also reduces development time and development costs.

[0053] Furthermore, generally, as the motor load decreases, the operating current decreases, allowing for a narrower power supply pattern design. Additionally, the amount of heat dissipated from the power supply circuit and inverter electronic components decreases, allowing for a smaller heat dissipation pattern, thus enabling a smaller motor drive board area when the motor load is reduced. Moreover, mounting the inverter on the motor drive board reduces noise during motor operation. Separating the heat generated by the operating current from the motor control board also reduces the noise filter required for the signal system and the area of ​​the heat dissipation pattern on the motor control board 241, thus enabling miniaturization of the motor control board.

[0054] In the case of a vertically articulated robot such as the robot arm body 200 in this embodiment, the force that causes the arm to bend and extend perpendicular to the arm placement plane is greater than the load that causes rotation in the horizontal direction because it is affected by the acceleration due to gravity during the arm lifting operation. For this reason, the drive boards may be designed in two sizes: one for the joints that rotate horizontally and another for the joints that bend and extend vertically. This can be achieved by making the drive board provided for the joints that bend and extend vertically larger and the drive board provided for the joints that rotate horizontally smaller.

[0055] Furthermore, the size of the motor drive board can be further reduced by gradually decreasing the board area as it moves towards the end-effector, resulting in a configuration where each joint of the robot arm has a different size board. In this case, the size of the motor drive board at the end-effector (tip) of the robot arm body 200 will be smaller than the size of all the motor drive boards at the other joints combined. In particular, in the case of horizontal articulated robots (SCARA robots), the self-weight (=motor load) decreases as it moves towards the end-effector, so designing the area of ​​the drive board placed towards the end-effector to gradually decrease is effective.

[0056] In this embodiment, the size of the motor drive board was considered based on its area, but it may also be considered based on its volume, weight, or mass. Depending on the electrical output of the motor to be controlled, at least one of the area, volume, weight, or mass of the motor drive board may be changed.

[0057] (Second embodiment) Next, the second embodiment will be described in detail. In the following, parts of the hardware and control system configuration that differ from the first embodiment will be illustrated and explained. Furthermore, parts that are the same as in the first embodiment will have the same configuration and operation as described above, and their detailed explanation will be omitted.

[0058] Figure 7 shows the details of the control blocks of the motor control board 241 and motor drive boards 251-256 in this embodiment. In this embodiment, the robot controller (higher-level control device) 340 and the motor drive boards 251-256 are electrically connected via a serial communication line 130. The power supply unit 350 and the motor drive boards 251-256 are connected so that power is supplied via a power cable 140. Furthermore, the encoders 211-216 are electrically connected to the motor drive boards 251-256 and then communicate with the control circuit 105 of each motor control board 241 via a position detection connector 123.

[0059] As described above, according to this embodiment, the power cable 140, serial communication line 130, and position detection connector 123 for encoders 211-216 are mounted on drive boards 251-256. This allows for the design of the boards and component mounting to be individually optimized for each joint, thus enabling a more advantageous design of the internal wiring of the robot arm body 200. Furthermore, the interfaces of the power lines, communication lines, and encoders of the motor control board 241 and the motor drive boards 251-256 can be consolidated in one place, and the effect of miniaturizing the motor control board 241 can also be expected. Note that this embodiment and its variations may be combined with the above-described embodiment and its variations in a given robot.

[0060] (Third embodiment) Next, the third embodiment will be described in detail. In the following, parts of the hardware and control system configuration that differ from the first and second embodiments will be illustrated and explained. Furthermore, parts that are the same as those in the first and second embodiments will be assumed to have the same configuration and operation as described above, and their detailed explanation will be omitted.

[0061] Figure 8 shows details of the control blocks of the motor control board 241 and motor drive boards 251-255 in this embodiment. In this embodiment, the control device 300 and each motor control board 241 are electrically connected via a power cable 140 and a serial communication line 130. Furthermore, the motor drive board 251 has inverters 106 and current detection units 107 mounted for two axes, and a major difference is that the motor drive board 251 alone controls the motors for both axes of the drive units 231 and 232.

[0062] Generally, due to the design characteristics of robot arms, the base side has more space for placing circuit boards than the end-effector side, making it possible to use larger circuit boards. On the base side, by configuring the ratio of motor control boards to motor drive boards to be 2:1, it is possible to further reduce the overall size of the robot arm body 200. In this embodiment, the drive devices 231 and 232 on the base side are used as an example, but the configuration is not limited to this. That is, the ratio of motor control boards to motor drive boards to be arranged at 2:1 at any point in each joint is also acceptable. Furthermore, this embodiment and its variations may be combined with the above-described embodiment and its variations in a given robot.

[0063] (Other embodiments) The processing procedures of the embodiments described above are specifically executed by the CPU 301 of the control device 300. Therefore, it is also possible to configure the device to read and execute a recording medium containing a software program capable of executing the above-described functions. In this case, the program read from the recording medium itself will realize the functions of each embodiment described above, and the program itself and the recording medium on which the program is recorded will constitute the present invention.

[0064] Furthermore, in each embodiment, the computer-readable recording medium was described as a ROM, RAM, or flash ROM, and the program was stored in the ROM, RAM, or flash ROM. However, the present invention is not limited to these embodiments. The program for carrying out the present invention may be recorded on any recording medium that is computer-readable. For example, an HDD, external storage device, recording disk, etc., may be used as the recording medium for supplying the control program.

[0065] Furthermore, while the various embodiments described above have explained the case where the robot arm body 200 is a multi-joint robot arm having multiple joints, the number of joints is not limited to this. Although a vertical multi-axis configuration was shown as the type of robot arm, the same configuration can be implemented with different types of joints such as horizontal multi-joint, parallel link, and Cartesian robots. It may also be applied to prosthetic arms, prosthetic legs, and powered suits (power assist suits) equipped with force-detecting sensors such as torque sensors.

[0066] Furthermore, the various embodiments described above are applicable to machines that can automatically perform actions such as extension and retraction, bending and straightening, vertical movement, horizontal movement, or rotation, or combinations thereof, based on information stored in a memory device provided in the control device.

[0067] It should be noted that the present invention is not limited to the embodiments described above, and many modifications are possible within the technical concept of the present invention. Furthermore, the effects described in the embodiments of the present invention are merely a list of the most preferred effects arising from the present invention, and the effects of the present invention are not limited to those described in the embodiments of the present invention. [Explanation of symbols]

[0068] 103 Communication Driver 104 Power supply circuit 105 Control circuit 106 Inverter 119 Power connector 120 Communication Connectors 121 Motor drive power connector 122 Inter-board connectors 123 Position detection connector 124 Spacer (support post) 130 serial communication lines 140 Power Cables 200 Robot Arm Body Links 201, 202, 203, 204, 205, 206 210 base 211, 212, 213, 214, 215, 216 encoders 221, 222, 223, 224, 225, 226 Torque Sensor 231, 232, 233, 234, 235, 236 Drive unit 241 Motor control board 251, 252, 253, 254, 255, 256 Motor drive board 300 Control device 340 Robot Controller 350 power supply 400 External Input Device

Claims

1. A robot having a first joint and a second joint, The first joint is provided with a first drive source, The second joint is provided with a second drive source, a first driving substrate that drives the first driving source and a second driving substrate that drives the second driving source have different sizes; A robot characterized by:

2. 2. The robot according to claim 1, The first drive substrate and the second drive substrate are made to have different sizes in accordance with the electrical outputs of the first drive source and the second drive source, respectively. A robot characterized by:

3. The robot according to claim 1 or 2, When the electrical output of the first drive source is larger than the electrical output of the second drive source, the first drive substrate is larger than the second drive substrate. A robot characterized by:

4. The robot according to any one of claims 1 to 3, When the electrical output of the first driving source is the largest and the electrical output of the second driving source is the smallest, the first driving substrate is the largest and the second driving substrate is the smallest. A robot characterized by:

5. The robot according to any one of claims 1 to 4, It has a third joint, The third joint is provided with a third drive source, When the electrical output of the third driving source is smaller than the electrical output of the first driving source and larger than the electrical output of the second driving source, a third driving substrate that drives the third driving source is smaller than the first driving substrate and larger than the second driving substrate. A robot characterized by:

6. The robot according to any one of claims 1 to 4, It has a third joint, The third joint is provided with a third drive source, an electrical output of the third driving source is smaller than an electrical output of the first driving source and is larger than an electrical output of the second driving source; The first driving substrate also drives the third driving source. A robot characterized by:

7. The robot according to claim 5 , a plurality of other joints different from the first joint, the second joint, the third joint, the first joint, the second joint, and the third joint; The other joints are each provided with a drive source, The drive sources of the other joints are each driven by the third drive board. A robot characterized by:

8. The robot according to claim 5 , a plurality of other joints different from the first joint, the second joint, the third joint, the first joint, the second joint, and the third joint; The other joints are each provided with a drive source, The first drive substrate, the second drive substrate, the third drive substrate, and each of the drive substrates that drive the drive sources of the other joints are changed in size. A robot characterized by:

9. The robot according to claim 8, A base that is a base of the robot and a predetermined portion that is a tip of the robot, The first driving substrate is provided on the base, and the second driving substrate is provided at the predetermined portion. A robot characterized by:

10. The robot according to claim 9, The second drive substrate is smaller than the first drive substrate. A robot characterized by:

11. The robot according to claim 9, The second drive substrate is smaller than each of the drive substrates that drive the drive sources of the other joints. A robot characterized by:

12. The robot according to claim 9, The sizes of the first drive substrate, the second drive substrate, the third drive substrate, and each drive substrate that drives the drive sources of the other joints are reduced from the base toward the predetermined portion. A robot characterized by:

13. The robot according to any one of claims 1 to 12, A common control board is connected to each drive board. A robot characterized by:

14. The robot according to claim 13, The drive board and control board are arranged vertically in a pair. A robot characterized by:

15. The robot according to claim 13 or 14, The drive board and the control board are arranged vertically on metal supports. A robot characterized by:

16. The robot according to claim 15, The support pillars are disposed at the four corners of the drive board and the control board. A robot characterized by:

17. The robot according to any one of claims 13 to 15, When the drive board and the control board are provided, the drive board is provided on the lower side and the control board is provided on the upper side. A robot characterized by:

18. The robot according to any one of claims 13 to 17, The drive board is provided with a power supply circuit and an inverter. A robot characterized by:

19. 19. The robot according to claim 13, The drive board is provided with a first connector for communication, a second connector for connection to a power source, and a third connector for supplying power to the target. A robot characterized by:

20. 20. The robot of claim 18, a control board is provided on the drive board so as to cover the power supply circuit and the inverter; A robot characterized by:

21. 20. The robot of claim 19, a control board is provided on the drive board so as not to cover the first connector, the second connector, and the third connector; A robot characterized by:

22. 22. The robot according to claim 13, the control board or the drive board is provided with a fourth connector connected to the detection means; A robot characterized by:

23. The robot according to any one of claims 1 to 3, When the first joint is a joint that moves in a vertical direction relative to a surface on which the robot is installed, and the second joint is a joint that moves in a horizontal direction relative to a surface on which the robot is installed, the first drive board is larger than the second drive board. A robot characterized by:

24. The robot according to any one of claims 1 to 23 is a vertical articulated robot or a horizontal articulated robot. A robot characterized by:

25. 25. The robot according to claim 1, The size is based on at least one of the area, volume, weight, or mass of the driving substrate; A robot characterized by:

26. A method for manufacturing an article, comprising the steps of: manufacturing an article by using a robot according to any one of claims 1 to 25;

27. ​​A method for controlling a robot having a first joint and a second joint, comprising: The first joint is provided with a first drive source, The second joint is provided with a second drive source, a first driving substrate that drives the first driving source and a second driving substrate that drives the second driving source have different sizes; The first driving source is driven by the first driving board, and the second driving source is driven by the second driving board, thereby controlling the robot. A control method comprising:

28. A control program capable of executing the control method according to claim 27.

29. A computer-readable recording medium storing the control program according to claim 28.

Images