Interlocking device, interlocking method, and control program

Abstract

To provide a technique capable of performing phase alignment without relying on an image including a first gear and an image including a second gear when engaging the first gear with the second gear.SOLUTION: An engagement device (1) comprises: a robot arm (11); a robot hand (13); and a controller (14) controlling the robot arm (11) and the robot hand (13). The controller (14) executes: (1) a half-engagement step (S11) of half-engaging a first gear (cylinder W1) with a second gear (shaft W2); (2) a first rotation step (S12) of normally rotating the first gear until the teeth of the first gear contact the teeth of the second gear; (3) a second rotation step (S13) of reversely rotating the first gear until the teeth of the first gear contact the teeth of the second gear; and (4) a third rotation step (S14) of normally rotating the first gear by a rotation angle smaller than a rotation angle at which the first gear is reversely rotated.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an engaging device and an engaging method for meshing a first gear with a second gear, and also to a control program for controlling such an engaging device. [Background technology]

[0002] Patent Document 1 describes an assembly device and an assembly method for assembling a gear mechanism by meshing gears with each other using a robot.

[0003] In the technology of Patent Document 1, a motor-side gear attached to the output shaft of a motor is fitted to a reducer gear already installed in the drive shaft of a product robot, and the motor output shaft is inserted into the reducer gear to assemble the reducer gear and the motor-side gear. Hereinafter, the newly fitted motor-side gear will be referred to as the first gear, and the reducer gear already installed in the drive shaft of the product robot will be referred to as the second gear.

[0004] In the technology of Patent Document 1, an image including the first gear and an image including the second gear are captured using an imaging device, and then image processing is performed on these images to obtain information such as the phase used to mate the first gear with the second gear. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-215345 Summary of the Invention [Problem to be solved by the invention]

[0006] In the technology of Patent Document 1, an image including the first gear and an image including the second gear are used to acquire information used to fit the first gear to the second gear. Therefore, it is preferable that the image including the first gear and the image including the second gear used in the technology of Patent Document 1 are clear. However, depending on the configuration of the product to be assembled, it may be difficult to capture clear images for reasons such as an insufficient amount of light irradiated onto at least one of the first gear and the second gear, or the second gear being embedded in a recessed position and the insertion hole for inserting the first gear being small.

[0007] One aspect of the present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a technology that enables phase alignment when fully meshing a first gear with a second gear without relying on an image including the first gear and an image including the second gear. [Means for solving the problem]

[0008] In order to solve the above problems, one embodiment of the present invention provides a meshing device that meshes a first gear with a second gear, and includes a robot arm, a robot hand attached to the tip of the robot arm and holding the first gear, and a controller that controls the robot arm and the robot hand.

[0009] In this meshing device, the controller is configured to execute the following steps: (1) a semi-meshing step of translating the first gear by controlling the robot arm and semi-meshing the first gear with the second gear; (2) a first rotation step of rotating the first gear forward by controlling the robot arm or the robot hand until the teeth of the first gear contact the teeth of the second gear; (3) a second rotation step of rotating the first gear reversely by controlling the robot arm or the robot hand until the teeth of the first gear contact the teeth of the second gear; (4) a third rotation step of rotating the first gear forward by a rotation angle smaller than the rotation angle when rotating the first gear reversely in the second rotation step by controlling the robot arm or the robot hand; and (5) a translation step of translating the first gear by controlling the robot arm and fully meshing the first gear with the second gear. [Effects of the Invention]

[0010] According to one aspect of the present invention, a technology can be provided that enables phase alignment when fully meshing a first gear with a second gear without relying on an image including the first gear and an image including the second gear. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a perspective view showing the configuration of an engagement device. [Figure 2] 2 is a block diagram showing the configuration of a controller provided in the meshing device shown in FIG. 1. FIG. [Figure 3] 2(a) and 2(b) are perspective views of a cylinder and a shaft to be engaged by the engagement device shown in FIG. 1. [Figure 4] 2A to 2C are plan views showing a cylinder and a shaft in each step of a meshing method carried out by a controller provided in the meshing device shown in FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0012] The configuration of an engagement device 1 according to one embodiment of the present invention will be described with reference to Figs. 1 and 2. Fig. 1 is a perspective view showing the configuration of the engagement device 1. Fig. 2 is a block diagram showing the configuration of a controller 14 provided in the engagement device 1. The tube W1 and shaft W2 that are engaged using the engagement device 1 will be described with reference to Fig. 3. Figs. 3(a) and 3(b) are perspective views of the tube W1 and shaft W2, respectively. The configuration of an engagement method M1 according to one embodiment of the present invention will be described with reference to Fig. 4. Fig. 4 is a plan view showing the tube W1 and shaft W2 in each step of the engagement method M1.

[0013] [Engagement device] As shown in Fig. 1, the engagement device 1 includes a robot arm 11, a force sensor 12, a robot hand 13, and a controller 14. The engagement device 1 is an engagement device that engages a tube W1 with a shaft W2. The robot arm 11 and the controller 14 are disposed on the main surface of a surface plate. Note that the surface plate is not labeled with a reference numeral.

[0014] <Robot arms and robot hands> In this embodiment, a vertical articulated robot arm is used as the robot arm 11. A six-axis force sensor is used as the force sensor 12. A three-way chuck is used as the robot hand 13 that holds the tube W1. The robot hand 13 may be capable of holding the tube W1 by a method other than gripping. Examples of holding methods other than gripping include suction, magnetic force, and electrostatic force. The robot hand 13 is attached to the tip of the robot arm 11 via the force sensor 12. In this embodiment, the direction parallel to the axis of the three-way chuck of the robot hand 13 and moving away from the tip of the robot arm 11 (vertical downward direction in FIG. 1 ) is defined as the positive z-axis direction. Two orthogonal directions that form a plane normal to the z-axis direction are defined as the positive x-axis direction and the positive y-axis direction. In FIG. 1 , the x-axis direction coincides with the left-right direction of the surface plate, and the y-axis direction coincides with the depth direction of the surface plate.

[0015] In the meshing device 1 and meshing method M1, the three-way chuck is rotated around the axis of the three-way chuck as the rotation axis, thereby rotating the tube W1 around the axis C1 of the tube W1 as the rotation axis. The mechanism for rotating the three-way chuck may be mounted on the robot arm 11 or on the robot hand 13. In the former case, the controller 14 rotates the three-way chuck by controlling the robot arm 11. In the latter case, the controller 14 rotates the three-way chuck by controlling the robot hand 13. In this embodiment, the description will be given assuming that the mechanism for rotating the three-way chuck is mounted on the robot hand 13.

[0016] <Force sensor> The force sensor 12 is a six-axis force sensor that detects forces Fx, Fy, Fz and moments Mx, My, Mz acting on the robot hand 13. Hereinafter, when it is not necessary to distinguish between the respective directions, the forces Fx, Fy, Fz will also be collectively referred to as force F, and the moments Mx, My, Mz will also be collectively referred to as moment M.

[0017] The force sensor 12 provides output signals representative of the detected force F and moment M to the controller 14 .

[0018] <controller> The controller 14 has a function of performing a specific task by controlling the robot arm 11 with reference to the output signal of the force sensor 12. In this embodiment, the specific task is to mesh the teeth T1 of the cylinder W1 with the teeth T2 of the shaft W2. The meshing method performed by the controller 14 in this task will be described later with reference to FIG. 4. FIG. 1 illustrates a state in which the axis C1 and the axis C2 are roughly aligned, but the cylinder W1 and the shaft W2 are separated. In the meshing method M1 described later, this state is the starting state.

[0019] The configuration of the controller 14 will be described with reference to Fig. 2. Fig. 2 is a block diagram showing the configuration of the controller 14.

[0020] 2, the controller 14 includes a processor 141, a primary memory 142, a secondary memory 143, a communication interface 144, and a bus 145. The processor 141, the primary memory 142, the secondary memory 143, and the communication interface 144 are connected to one another via the bus 145. An example of a device that can be used as the controller 14 is a workstation that constitutes a cloud server.

[0021] A control program P is stored in the secondary memory 143. The processor 141 loads the control program P stored in the secondary memory 143 onto the primary memory 142. The processor 141 then executes each process included in a meshing method M1 (described later) in accordance with instructions included in the control program P loaded onto the primary memory 142. An example of a device that can be used as the processor 141 is a CPU (Central Processing Unit). An example of a device that can be used as the primary memory 142 is a semiconductor RAM (Random Access Memory). An example of a device that can be used as the secondary memory 143 is an HDD (Hard Disk Drive).

[0022] The communication interface 144 is an interface for communicating with the robot arm 11 and the robot hand 13 via a network. An example of an interface that can be used as the communication interface 144 is an Ethernet (registered trademark) interface. Also, examples of networks that can be used include a PAN (Personal Area Network), a LAN (Local Area Network), a CAN (Campus Area Network), a MAN (Metropolitan Area Network), a WAN (Wide Area Network), a GAN (Global Area Network), or an internetwork including these networks. The internetwork may be an intranet, an extranet, or the Internet.

[0023] The control program P for causing the processor 141 to execute the meshing method M1 may be recorded on a computer-readable, non-transitory, tangible recording medium. This recording medium may be the secondary memory 143 or another recording medium. For example, a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like may be used as the other recording medium. The control program P achieves the same effects as the meshing device 1 and meshing method M1 described below.

[0024] [Cylinder and shaft] As shown in Fig. 3(a), the tube W1 is a cylindrical member made of metal. However, the material constituting the tube W1 is not limited to metal, and may be, for example, resin or ceramic.

[0025] The inner wall of the tube W1 is provided with a plurality of grooves parallel to its axis C1. The grooves correspond to a plurality of teeth T2 of the tube W1, which will be described later. Because the grooves are provided on the inner wall of the tube W1, the portions of the inner wall of the tube W1 that do not have the grooves function as teeth T1. Therefore, the tube W1 is one form of an internal gear. The tube W1 is an example of a first gear, and the teeth T1 are an example of teeth of the first gear.

[0026] As shown in Fig. 3(b), the shaft W2 is a cylindrical member made of metal. However, the material constituting the shaft W2 is not limited to metal, and may be, for example, resin or ceramic.

[0027] A plurality of teeth T2 are provided on the outer wall of the shaft W2 in parallel with the axis C2 of the shaft W2. The shaft W2 is an example of a second gear, and the teeth T2 are an example of teeth of the second gear.

[0028] In this embodiment, the shaft W2 is fixed to the surface plate via a metal block, which is also not provided with a reference number.

[0029] In this embodiment, the heights of the tube W1 and the axis W2 (lengths in a direction parallel to the axis) are equal to each other. However, the heights of the tube W1 and the axis W2 are not limited to this and can be determined as appropriate.

[0030] However, the first gear and the second gear that are meshed by the meshing device 1 are not limited to the cylinder W1 and the shaft W2. The combination of the first gear and the second gear may be any combination that can fully mesh the first gear and the second gear by translating the first gear at least in a direction parallel to the axis when the first gear and the second gear are in a partially meshed state with their respective phases being in phase.

[0031] Other examples of combinations of the first gear and the second gear include combinations in which one or both are spur gears, combinations in which one or both are helical gears, and combinations of a rack and pinion. In the case of a rack and pinion, the pinion is often the first gear and the rack is the second gear. However, in combinations of two gears, which one is the first gear can be selected appropriately depending on the configuration of the assembled product.

[0032] Furthermore, "partial meshing" means that the first gear and the second gear are lightly meshed, and "full meshing" means that the first gear and the second gear are completely meshed. In other words, "partial meshing" means that the assembly of the first gear and the second gear is not yet complete, and "full meshing" means that the assembly of the first gear and the second gear is complete.

[0033] In this embodiment, specific terms indicating the meshing state between the first gear and the second gear are defined as follows. These states are clearly distinguished in this embodiment depending on the type of force and moment detected by the force sensor 12.

[0034] "Interference" refers to a physical state in which, when the first gear is translated axially relative to the second gear, the lower end surfaces of the teeth T1 of the first gear collide with the upper end surfaces of the teeth T2 of the second gear, preventing further translation. This state is identified primarily by detecting the axial force Fz. The semi-engagement step S11, described later, aims to resolve this "interference."

[0035] "Clearance" refers to a physical state in which the above-mentioned "interference" is eliminated, and when the first gear and the second gear are viewed from the side, the upper end of the shaft W2 and the lower end of the cylinder W1 slightly overlap, and the above-mentioned "interference" is eliminated. In other words, the "clearance" state is a state in which the tooth T1 of the first gear falls into the recess between the tooth T2 of the second gear, there is no axial obstruction, and the tooth surfaces of the tooth T1 and the tooth T2 are not in contact with each other in the rotational direction. In this state, no particular force (e.g., Fz) or moment (e.g., Mz) is detected. The first rotation process S12, described later, starts from this "clearance" state.

[0036] "Tooth surface contact" refers to a state in which, when the first gear is rotated from the "clearance" state, the tooth surface of the first gear tooth T1 and the tooth surface of the second gear tooth T2 physically contact each other within the backlash range. This state is identified primarily by detecting the moment Mz about the rotation axis. The first rotation step S12 and second rotation step S13, which will be described later, aim to identify the backlash limit by detecting this "tooth surface contact" and find the optimal phase of the first gear relative to the second gear.

[0037] In the case of the cylinder W1 and the shaft W2, partial meshing refers to a state in which the teeth T1 near the bottom end surface of the cylinder W1 and the teeth T2 near the top end surface of the shaft W2 are meshed, and most of the teeth T1 and T2 are not meshed with each other. On the other hand, full meshing refers to a state in which the shaft W2 is housed inside the cylinder W1, and when viewed along the axial direction, all of the teeth T1 and all of the teeth T2 are meshed with each other.

[0038] The above definitions of half meshing and full meshing can also be applied to the case where a thin (low height) spur gear is used as at least one of the first gear and the second gear.

[0039] In addition, in the partially engaged cylinder W1 and second gear (shaft W2), the state in which the phases are in sync is when the axis (axis C1) of the first gear (cylinder W1) and the axis (axis W2 )of This means that the axes (axis C2) are aligned, and the teeth (tooth T1) of the first gear (cylinder W1) and the teeth (tooth T2) of the second gear (shaft W2) are not in contact with each other.

[0040] When the phases of the partially engaged cylinder W1 and shaft W2 are aligned, the axis C1 and axis C2 are aligned and the teeth T1 and T2 are not in contact, so by simply translating the cylinder W1, full meshing can be achieved without the teeth T1 and T2 coming into contact with each other, and therefore no damage occurs to the teeth T1 and T2.

[0041] On the other hand, if the phases of the partially engaged cylinder W1 and shaft W2 are not aligned, If you translate the cylinder W1, Part of tooth T1 and tooth T2 of Contact with some vinegar Therefore, even if full meshing can be achieved, damage will occur to at least one of the teeth T1 and T2, and in some cases full meshing may not be possible.

[0042] The meshing device 1 can align the phases of the partially meshed cylinder W1 and shaft W2, and can therefore fully mesh the teeth T1 and T2 without damaging them.

[0043] The states of the meshing device 1, the tube W1, and the shaft W2 shown in FIG. 1 are set in order to explain the meshing device 1 and the meshing method M1. The meshing device 1 is used in a production line that manufactures products by automatically assembling them. The shaft W2 is an example of a part that is already incorporated into a product in the middle of assembly. In the production line, the shaft W2 is fixed in a predetermined position as part of the product in the middle of assembly. On the other hand, the tube W1 is a part that will be incorporated into the product in the middle of assembly.

[0044] [Engagement method] 4, the meshing method M1 includes a semi-meshing step S11, a first rotation step S12, a second rotation step S13, a third rotation step S14, and a translation step S15. In the meshing device 1, the meshing method M1 is executed by the controller 14. One embodiment of the present invention also includes a control program P that controls the meshing device 1 and causes the controller 14 to execute the meshing method M1.

[0045] 4(a) to 4(f) are plan views obtained by viewing the upper end surface of the cylinder W1 (the end surface located on the upper side in FIG. 3(a)) from the negative z-axis side (i.e., the side of the force sensor 12 and robot hand 13) in the state of the meshing device 1, cylinder W1, and shaft W2 shown in FIG. 1. Because the cylinder W1 is located above the shaft W2 (the negative z-axis side), the shaft W2 can be seen from the hollow of the cylinder W1. However, in practice, because the force sensor 12 and robot hand 13 are located above the cylinder W1, it is not possible to capture an image of the cylinder W1 and shaft W2 from external space.

[0046] In Figure 4, (a) shows the initial state before performing the meshing method M1, (b) shows the state after performing the semi-meshing step S11 (i.e., the semi-meshed state), (c) shows the state after performing the first rotation step S12, (d) shows the state after performing the second rotation step S13, (e) shows the state after performing the third rotation step S14, and (f) shows the state after performing the translation step S15 (i.e., the fully meshed state).

[0047] <Starting state> In the meshing method M1, as shown in FIG. 1 and FIG. 4(a), the starting state is a state in which the axis C1 and the axis C2 are roughly aligned, but the cylinder W1 and the axis W2 are separated.

[0048] 1 is fixed at a predetermined position on a surface plate, and the block can fix the axis W2 at an approximately predetermined position. Therefore, the controller 14 can obtain the position and orientation of the axis C2 when the axis W2 is fixed at the predetermined position of the block.

[0049] Meanwhile, the robot hand 13 uses a three-way chuck to grip the tube W1 so that the axis of the three-way chuck roughly coincides with the axis C1 of the tube W1. The controller 14 can obtain the axis of the three-way chuck, and therefore can obtain the position and orientation of the axis C1 of the tube W1 gripped by the three-way chuck.

[0050] The controller 14 controls the robot arm 11 so that the axis C1 and the axis C2 are aligned and so that the cylinder W1 and the axis W2 are spaced apart by a predetermined distance. In this initial state, the predetermined position and orientation of the axis C2 acquired by the controller 14 do not necessarily match the actual position and orientation of the axis C2, and the predetermined position and orientation of the axis C1 acquired by the controller 14 do not necessarily match the actual position and orientation of the axis C1.

[0051] <Semi-meshing process> In the semi-meshing step S11, the controller 14 controls the robot arm 11 to at least translate the cylinder W1, so that the teeth T1 of the cylinder W1 are semi-meshed with the teeth T2 of the shaft W2.

[0052] Specifically, the controller 14 translates the cylinder W1 vertically downward (in the positive direction of the z-axis in the coordinate system shown in FIG. 1, or in the direction toward the depth of the paper in FIG. 3) to a position where the upper end of the axis W2 and the lower end of the cylinder W1 slightly overlap when viewed from the side. Note that the position where the upper end of the axis W2 and the lower end of the cylinder W1 slightly overlap when viewed from the side of the cylinder W1 may be provided to the controller 14 in advance.

[0053] If the phases of the cylinder W1 and the shaft W2 happen to match in the initial state, the force sensor 12 will not detect any force F or moment M until the semi-meshing step S11 is completed. Therefore, if the force sensor 12 does not detect the force F or moment M until the semi-meshing step S11 is completed, the controller 14 determines that the phases of the cylinder W1 and the shaft W2 are matched. In this case, the controller 14 omits the execution of the first rotation step S12, the second rotation step S13, and the third rotation step S14, and executes the translation step S15, which will be described later.

[0054] On the other hand, if the force sensor 12 detects at least one of the force F and the moment M before the semi-meshing step S11 is completed, the controller 14, which has received the output signal from the force sensor 12, immediately stops the operation of the robot arm 11, thereby stopping the translation of the cylinder W1. In this state, the upper end surface of the shaft W2 and the lower end surface of the cylinder W1 are interference is doing. That is, this state is an example of the "interference" state described above. Furthermore, when this state is viewed from above, the degree of overlap between the tooth T1 and the tooth T2 is considered to be approximately the same as the initial state shown in FIG. 4(a).

[0055] The controller 14 can obtain the relative position and orientation of the axis C1 with respect to the axis C2 based on the components of the force F and moment M represented by the output signal obtained from the force sensor 12. The controller 14 controls the robot hand 13 in accordance with the relative position and orientation of the axis C1 with respect to the axis C2, thereby matching the position and orientation of the axis C1 with the position and orientation of the axis C2.

[0056] Although the position and orientation of the axis C1 and the position and orientation of the axis C2 are the same, a part of the tooth T1 and a part of the tooth T2 are Interfere When the force sensor 12 is in the negative direction of the z-axis, a portion of the tooth T1 and a portion of the tooth T2 are in contact with each other over the entire circumference of the cylinder W1 and the shaft W2, and the force sensor 12 detects a force Fz acting in the negative direction of the z-axis (hereinafter referred to as a negative force Fz).

[0057] When the controller 14 receives an output signal representing only the negative force Fz, it determines that the axis C1 and the axis C2 are aligned, but a part of the tooth T1 and a part of the tooth T2 are aligned. Interfere In this case, the controller 14 determines that Robot Hand 13 By controlling the above, the upper end surface of the shaft W2 and the lower end surface of the tube W1 are kept in slight contact with each other (i.e., a state in which a slight negative force Fz is detected), and the tube W1 is rotated clockwise (CW) around the axis C1 as the rotation axis.

[0058] In the following description, rotating the barrel W1 clockwise is referred to as "forward rotation," and rotating the barrel W1 counterclockwise (CCW) is referred to as "reverse rotation."

[0059] Here, as shown in FIG. 4(b), the teeth T1 and T2 Interfere When the negative force Fz is no longer detected, the controller 14 immediately stops the operation of the robot arm 11. By performing the above steps, the cylinder W1 and the shaft W2 are "Clearance" state, i.e., Cylinder W1 is on axis W2 without interfering with each other It becomes semi-engaged.

[0060] In addition, in order to minimize damage that may occur to the upper end surface of the shaft W2 and the lower end surface of the tube W1, when rotating the tube W1 in the forward direction, it is advisable to perform the forward rotation of the tube W1 while the tube W1 is separated from the shaft W2 (in a state where the negative force Fz is not detected).

[0061] However, when this method is adopted, it is not possible to monitor the force Fz while rotating the cylinder W1 in the forward direction. .the Therefore, When the cylinder W1 is moved downward to a position where the upper end of the shaft W2 and the lower end of the cylinder W1 slightly overlap when viewed from the side, Teeth T1 and T2 In an interfering state Therefore, when this method is adopted, it is preferable to repeat the following steps (1) to (3). If a negative force Fz is not detected after step (3) is performed, the controller 14 determines whether the tooth T1 and the tooth T2 are in a negative state. Interfere(1) Moving the cylinder W1 upward to separate the cylinder W1 from the axis W2, (2) rotating the cylinder W1 forward by a small angle (for example, 1°), and (3) moving the cylinder W1 downward to a position where the upper end of the axis W2 and the lower end of the cylinder W1 slightly overlap when viewed from the side.

[0062] As described above, the semi-meshing step S11 is a step of realizing the "clearance" state by rotating the barrel W1 clockwise until the force Fz is no longer detected. However, in the "clearance" state, the teeth T1 and T2 simply do not interfere with each other. Therefore, the first rotation step S12, second rotation step S13, and third rotation step S14, which will be described later, start from the "clearance" state.

[0063] The method for performing the semi-meshing step S11 is not limited to the above-described method. As a method for semi-meshing the teeth T1 of the cylinder W1 with the teeth T2 of the shaft W2, for example, a vision sensor, which is a type of imaging device, can be used, or offline teaching, in which teaching is performed on a personal computer, can also be used.

[0064] <First rotation process> In the first rotation step S12, the controller 14 controls the robot hand 13 to rotate the cylinder W1 in the forward direction until the tooth T1 of the cylinder W1 comes into contact with the tooth T2 of the shaft W2 (see FIG. 4(c)). When the cylinder W1 is rotated in the forward direction so that the tooth T1 comes into contact with the tooth T2, the force sensor 12 detects a moment Mz in the counterclockwise direction (hereinafter referred to as a negative moment Mz).

[0065] The controller 14 refers to the output sensor of the force sensor 12. When the controller 14 acquires an output signal representing a negative moment Mz in the first rotation step S12, the controller 14 controls the robot hand 13 to immediately stop the forward rotation of the tube W1. This state is an example of the "tooth surface contact" state described above. The robot hand 13 also provides the controller 14 with a rotation angle signal that indicates the rotation angle θ1 of the three-way chuck in the robot hand 13 at this time.

[0066] <Second rotation process> In the second rotation step S13, the controller 14 controls the robot hand 13 to rotate the cylinder W1 in the reverse direction until the teeth T1 of the cylinder W1 come into contact with the teeth T2 of the shaft W2 (see (d) of FIG. 4). reverseWhen the tooth T1 comes into contact with the tooth T2 due to the rotation, the force sensor 12 detects a clockwise moment Mz (hereinafter referred to as a positive moment Mz).

[0067] The controller 14 refers to the output sensor of the force sensor 12. When the controller 14 acquires an output signal representing a positive moment Mz in the second rotation step S13, the controller 14 controls the robot hand 13 to immediately stop the reverse rotation of the tube W1. This state is an example of the "tooth surface contact" state described above. The robot hand 13 also provides the controller 14 with a rotation angle signal that indicates the rotation angle θ2 of the three-way chuck in the robot hand 13 at this time. The purpose of the first rotation step S12 and the second rotation step S13 performed in this manner is to accurately find the center of backlash. To this end, in the first rotation step S12 and the second rotation step S13, the moment Mz about the rotation axis is monitored to identify the limit points of "tooth surface contact" in each of the forward and reverse rotations.

[0068] <Third rotation process> In the third rotation step S14, the controller 14 controls the robot hand 13 to rotate the tube W1 forward by a rotation angle smaller than the rotation angle when the tube W1 is rotated reversely in the second rotation step S13 (see (e) of FIG. 4). In addition, the rotation angle when the tube W1 is rotated forward in the third rotation step S14 is preferably 1 / 2 of the rotation angle when the tube W1 is rotated reversely in the second rotation step S13.

[0069] The controller 14 acquires the rotation angles θ1 and θ2 represented by the rotation angle signal acquired from the robot hand 13, and calculates the rotation angle when the tube W1 is rotated in the reverse direction in the second rotation step S13 by calculating the difference between the rotation angles θ1 and θ2. This makes it possible to realize a state in which the teeth T1 and T2 do not contact each other in the semi-engaged state. In other words, it is possible to align the phases of the tube W1 and the shaft W2 in the semi-engaged state. In this way, the purpose of the series of first rotation step S12, second rotation step S13, and third rotation step S14 is to align the phases of the cylinder W1 and the axis W2 as closely as possible. Note that the state obtained after carrying out the first rotation step S12, second rotation step S13, and third rotation step S14 can be said to be an example of a "clearance" state, but it can also be said to be a "clearance" state after intentionally aligning the phases, that is, a true "clearance" state.

[0070] <Translation process> In the translation step S15, the controller 14 controls the robot arm 11 to translate the cylinder W1 so that the cylinder W1 is fully engaged with the shaft W2 (see (f) of FIG. 4).

[0071] Specifically, the controller 14 translates the tube W1 vertically downward (in the positive direction of the z-axis in the coordinate system shown in Figure 1, or in the direction toward the back of the paper in Figure 3) to a position where the axis W2 is contained inside the tube W1 when viewed from the side (a position where the upper end surface of the tube W1 and the upper end surface of the axis W2 are aligned).

[0072] In the meshing method M1, the position and orientation of the axis C1 can be aligned with the position and orientation of the axis C2 by performing the partial meshing step S11. Also, in the meshing method M1, the phases of the tube W1 and the axis W2 can be aligned by performing the first rotation step S12 to the third rotation step S14. Therefore, in the translation step S15, the tube W1 and the axis W2 can be fully meshed together simply by translating the tube W1. It should be noted that the force sensor 12 does not detect any force F or moment M during the period in which the translation step S15 is being performed, nor when the translation step S15 is completed and "full meshing" is achieved.

[0073] [Effects of the meshing device and meshing method] According to the meshing device 1, the tube W1 and Axis W2 The beginning of the separation In this state, the controller 14 executes an engagement method M1 including a semi-engagement step S11, a first rotation step S12, a second rotation step S13, a third rotation step S14, and a translation step S15. Therefore, phase alignment can be performed so that the barrel W1 does not come into contact with the shaft W2.

[0074] In the first rotation step S12, the second rotation step S13, and the third rotation step S14, phase alignment is performed based on the rotation angle of the cylinder W1 when the teeth T1 of the cylinder W1 are in contact with the teeth T2 of the shaft W2. Therefore, the meshing device 1 and the meshing method M1 can perform phase alignment without relying on an image including the cylinder W1 and an image including the shaft W2.

[0075] Furthermore, by the controller 14 performing the translation step S15, the cylinder W1 can be translated in a state where the cylinder W1 is not in contact with the shaft W2, and the cylinder W1 can be fully meshed with the shaft W2. In this way, the meshing device 1 and the meshing method M1 can transition the cylinder W1 and the shaft W2 from a semi-meshed state to a fully meshed state in a state where the teeth T1 of the cylinder W1 are not in contact with the teeth T2 of the shaft W2. Therefore, the meshing device 1 and the meshing method M1 have the secondary effect of reducing the possibility of the teeth T1 and T2 being damaged (or scratched) or getting stuck.

[0076] Furthermore, by setting the rotation angle of the barrel W1 in the forward direction in the third rotation step S14 to half the rotation angle of the barrel W1 in the reverse direction in the second rotation step S13, the distance between the teeth T1 and T2 in the semi-engaged state can be maximized. That is, in the semi-engaged state, the phases of the barrel W1 and the shaft W2 can be matched. Figure 4(e) shows the state in which the phases of the barrel W1 and the shaft W2 are matched.

[0077] The meshing device 1 also includes a force sensor 12 interposed between the robot arm 11 and the robot hand 13. In the meshing device 1, the controller 14 preferably identifies that the tooth T1 of the tube W1 has come into contact with the tooth T2 of the shaft W2 in the first rotation step S12 and the second rotation step S13 by referring to the output signal of the force sensor 12. This allows the controller 14 to reliably detect that the tooth T1 has come into contact with the tooth T2 without relying on an image including the tube W1 and an image including the shaft W2.

[0078] [Additional Notes] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0079] 1. Interlocking device 11 Robotic Arm 12 Force sensor 13 Robot Hand 14 Controller W1 Cylinder (1st gear) C1 axis center T1 tooth (1st gear tooth) W2 shaft (second gear) C2 axis center T2 tooth (2nd gear tooth)

Claims

1. A meshing device that meshes a first gear with a second gear, a robot arm; a robot hand attached to a tip of the robot arm and holding the first gear; a force sensor interposed between the robot arm and the robot hand; and a controller that controls the robot arm and the robot hand, The controller (1) controls the robot arm to translate the first gear and detect forces and moments using the force sensor, and when detecting at least axial forces in the first gear and the second gear among the forces and moments, rotates the first gear relatively so that the teeth of the first gear and the teeth of the second gear do not interfere with each other, thereby partially meshing the first gear with the second gear; and (2) controls the robot arm or the robot hand to rotate the first gear until the teeth of the first gear come into contact with the teeth of the second gear. (3) a second rotation step of rotating the first gear in a reverse direction by controlling the robot arm or the robot hand until a tooth of the first gear contacts a tooth of the second gear; (4) a third rotation step of rotating the first gear in a forward direction by a rotation angle smaller than the rotation angle when rotating the first gear in a reverse direction in the second rotation step by controlling the robot arm or the robot hand; and (5) a translation step of translating the first gear and fully meshing the first gear with the second gear by controlling the robot arm, the controller determines, by referring to the output signal of the force sensor, that the teeth of the first gear have come into contact with the teeth of the second gear during the first rotation process and the second rotation process. A meshing device characterized by:

2. The rotation angle when rotating the first gear forward in the third rotation process is 1 / 2 of the rotation angle when rotating the first gear backward in the second rotation process.

2. The engagement device according to claim 1.

3. A method for meshing a first gear with a second gear using a robot arm, a robot hand attached to a tip of the robot arm and holding a first gear, a force sensor interposed between the robot arm and the robot hand, and a controller controlling the robot arm and the robot hand, comprising: a semi-meshing step of controlling the robot arm to translate the first gear and detect a force and a moment using the force sensor, and when at least an axial force in the first gear and the second gear is detected among the forces and moments, rotating the first gear relatively so that teeth of the first gear and teeth of the second gear do not interfere with each other, thereby semi-meshing the first gear with the second gear; a first rotation step of rotating the first gear in a forward direction by controlling the robot arm or the robot hand until teeth of the first gear come into contact with teeth of the second gear; a second rotation step of rotating the first gear in a reverse direction by controlling the robot arm or the robot hand until teeth of the first gear come into contact with teeth of the second gear; a third rotation step of rotating the first gear forward by a rotation angle smaller than the rotation angle when the first gear is rotated in the reverse direction in the second rotation step by controlling the robot arm or the robot hand; a translation step of translating the first gear and fully meshing the first gear with the second gear by controlling the robot arm, the controller determines, by referring to the output signal of the force sensor, that the teeth of the first gear have come into contact with the teeth of the second gear during the first rotation process and the second rotation process. A meshing method characterized by the above.

4. The rotation angle when rotating the first gear forward in the third rotation process is 1 / 2 of the rotation angle when rotating the first gear backward in the second rotation process.

4. The method of claim 3, wherein the engagement is performed in a manner similar to that described in claim 3.

5. a robot arm; a robot hand attached to a tip of the robot arm and holding a first gear; a force sensor interposed between the robot arm and the robot hand; and a controller for controlling the robot arm and the robot hand, wherein the control program controls an engagement device that engages the first gear with a second gear, (1) a semi-engagement process of controlling the robot arm to translate the first gear and detect forces and moments using the force sensor, and when at least axial forces in the first gear and the second gear are detected among the forces and moments, rotating the first gear relatively so that the teeth of the first gear and the teeth of the second gear do not interfere with each other, thereby semi-engaging the first gear with the second gear; and (2) a first rotation of rotating the first gear forward by controlling the robot arm or the robot hand until the teeth of the first gear come into contact with the teeth of the second gear. (3) a second rotation step of rotating the first gear in a reverse direction by controlling the robot arm or the robot hand until the teeth of the first gear come into contact with the teeth of the second gear; (4) a third rotation step of rotating the first gear in a forward direction by a rotation angle smaller than the rotation angle when the first gear is rotated in the reverse direction in the second rotation step by controlling the robot arm or the robot hand; and (5) a translation step of translating the first gear and fully meshing the first gear with the second gear by controlling the robot arm, causing the controller to further execute a process of identifying, by referring to an output signal of the force sensor, that a tooth of the first gear has come into contact with a tooth of the second gear in the first rotation step and the second rotation step; Control program for.

6. The rotation angle when rotating the first gear forward in the third rotation process is 1 / 2 of the rotation angle when rotating the first gear backward in the second rotation process.

6. The control program according to claim 5.

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