Robot mechanism

Abstract

The invention provides a robot mechanism capable of suppressing restriction of a cable on operation of a robot arm. According to the method, a robot mechanism is used, and the robot mechanism is provided with a first robot arm which is supported by a supporting body and is provided with a joint; a second robot arm that is supported by the support body; the front-end equipment is arranged at the front end part of the first mechanical arm; a cable disposed along the second robot arm and connected to the front-end device via a front end portion of the second robot arm; and a control unit that controls the operation of the tip of the second robot arm in accordance with the operation of the first robot arm.

Description

Technical Field

[0001] This invention relates to a robotic mechanism. Background Technology

[0002] In recent years, the introduction of robotic mechanisms incorporating robotic arms has been promoted with the aim of automating or improving the efficiency of operations. Because light sources, cameras, or other tools can be freely mounted on the front end of the robotic arm, it can replace human hands and efficiently perform various tasks. Currently, power is supplied to the light source or camera mounted on the front end of the robotic arm, or cables for input and output electrical signals are connected along the robotic arm.

[0003] Patent document 1 (Japanese Patent Application Publication No. 2018-79514) describes an example of using two robotic arms to hold a cable.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2018-79514 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In automated inspection and assembly equipment, adjustments must be performed before automatic inspection and assembly to prevent cables from coming into contact with the robotic arm or the object being inspected and assembled, as described above. Failure to perform these adjustments adequately may result in obstruction of the robotic arm's movement, cable breakage, or cables coming into contact with the object being inspected and assembled.

[0009] The purpose of this invention is to provide a robot mechanism that can suppress the restriction of movement by cables even without the above-mentioned adjustment work.

[0010] Other objectives and novel features will become clear from the description and accompanying drawings in this specification.

[0011] Methods for solving problems

[0012] The following is a brief summary of representative embodiments of the implementation methods disclosed in this application.

[0013] One embodiment of the robot mechanism includes: a first robotic arm supported by a support body and having joints; a second robotic arm supported by the support body; a front end device disposed at the front end of the first robotic arm; a cable disposed along the second robotic arm and connected to the front end device via the front end of the second robotic arm; and a control unit that controls the movement of the front end of the second robotic arm according to the movement of the first robotic arm.

[0014] Invention Effects

[0015] The effects obtained by representative inventions disclosed in this application will be briefly explained below.

[0016] According to the present invention, a robot mechanism is provided that can suppress the restriction of the movement of the robotic arm by the cable. Attached Figure Description

[0017] Figure 1 This is a schematic diagram showing the overall structure of the automatic inspection device.

[0018] Figure 2 This is a schematic diagram showing the overall structure of the automatic inspection device of Modified Example 1.

[0019] Figure 3 This is a schematic diagram showing the overall structure of the automatic inspection device of Modified Example 2.

[0020] Figure 4 This is a schematic diagram showing the overall structure of the automatic inspection device of Modified Example 3.

[0021] Figure 5 This is a schematic diagram showing the overall structure of the automatic inspection device in Modified Example 4. Detailed Implementation

[0022] Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings. Furthermore, in all the drawings used to describe the embodiments, components with the same function are labeled with the same reference numerals, and repeated descriptions are omitted. Additionally, in the following embodiments, descriptions of the same or identical parts will generally not be repeated unless specifically required. Furthermore, in the drawings describing the embodiments, shaded lines are sometimes used in top views or perspective views, etc., to facilitate understanding of the structure. Also, in the drawings describing the embodiments, shaded lines are sometimes omitted in sectional views to facilitate understanding of the structure.

[0023] <Details on areas for improvement>

[0024] At the equipment inspection and assembly site, automated inspection and assembly technology using robotic arms is applied to achieve automation and efficiency. The power cables that enable the robotic arm's movements are routed inside the robotic arm to supply power, and therefore are not affected by the robotic arm's movements. Such power cables do not limit the impact on the robotic arm's movements.

[0025] However, cables used to power light sources, cameras, or other tools mounted at the front end of the robotic arm, or to input / output electrical signals, cannot be routed inside the robotic arm and are sometimes located outside the robotic arm.

[0026] If the cable is positioned along the robotic arm, and the cable length is too short, it may break due to excessive stretching, bending, or compression as the robotic arm moves. Therefore, it is necessary to ensure that the cable length is longer than the robotic arm length and that the cable is positioned on the robotic arm with appropriate cable deformation (slack).

[0027] On the other hand, if the cable is too long, the cable slack will increase, and the cable may come into contact with the robotic arm or the object being inspected. This could lead to the cable breaking or damage to the robotic arm or the object being inspected. Therefore, when cables are externally mounted on the robotic arm, the cable length needs to be adjusted to properly manage slack.

[0028] As a method to prevent cables from getting caught in the robotic arm and to prevent cables from snagging on the objects being inspected or assembled, a method using cable clamps to secure the cables to the robotic arm and using a reel to adjust the cable length has been considered. However, this method has the following problems: there is a risk of the cables getting caught when the joints of the robotic arm rotate, and the tension in the reel needs to be adjusted according to the type of cable. Alternatively, a wireless method could be considered that supplements the power supply and data communication of the cables entirely with wireless communication, eliminating the need for external cables on the robotic arm. However, when the power supply and data communication volumes are very high, wireless communication alone is considered insufficient, and the introduction of communication equipment would incur significant costs.

[0029] As described above, in a robotic mechanism having a cable connected to the front end of a robotic arm, there is room for improvement in suppressing the constraint of the cable on the movement of the robotic arm.

[0030] Therefore, in the following embodiments, measures are taken to address the aforementioned shortcomings. The technical concept of this embodiment, in which these measures are taken, will be explained below.

[0031] (Implementation Method)

[0032] As an example of a robotic mechanism, this section outlines an automated inspection device. Figure 1 This is a schematic diagram showing the structure of an automatic inspection device equipped with the robot mechanism of this embodiment.

[0033] like Figure 1 As shown, the first robotic arm 101 and the second robotic arm 102 are supported by a support body 103, and each has at least one joint 104 and at least one arm 105 between its side end and front end of the support body. Here, the first robotic arm 101 and the second robotic arm 102 are fixed to the support body 103. Furthermore, in Figure 1The diagram shows a first robotic arm 101 with three joints 104 and a second robotic arm 102 with one joint 104, but the number of joints 104 is not limited to this and can also be multiple. By having joints in the second robotic arm 102, the degree of freedom of movement of the second robotic arm 102 is increased, thereby increasing the degree of freedom of movement of the first robotic arm 101. The joint referred to in this application refers to a rotational mechanism between two arms of a robotic arm, which enables one of the two arms to rotate relative to the other.

[0034] A front-end device (end actuator) 106, serving as a detection unit for inspecting an object (inspection object 108), is connected to the front end of the first robotic arm 101. Here, the inspection unit is used as the front-end device 106. That is, the front-end device 106 is used to perform inspection processing on the object. An insulated wire, i.e., a cable 107, for supplying power to the front-end device 106 is connected to the front-end device 106. The cable 107 is connected to the power supply 109 via the second robotic arm 102. That is, the cable 107 is arranged from the power supply 109 along the second robotic arm 102 and connected to the front-end device 106 via the front end of the second robotic arm 102.

[0035] Multiple portions of the cable 107 are secured to the arm 105, for example, by straps 120. The joints 104 of the first robotic arm 101 are rotatable, allowing the arm 105 and the front-end device 106 of the first robotic arm 101 to move freely by rotating in any direction. The joints 104 of the second robotic arm 102 are rotatable, allowing the arm 105 and the front end of the second robotic arm 102 to move freely by rotating in any direction.

[0036] The first robotic arm 101 and the second robotic arm 102 are respectively connected to the control unit 10. The control unit 10 includes a first robotic arm drive indicator 1, a second robotic arm drive indicator 2, and a first robotic arm / second robotic arm cooperation mechanism 3. The first robotic arm / second robotic arm cooperation mechanism 3 is a mechanism that enables the first robotic arm drive indicator 1 and the second robotic arm drive indicator 2 to move synchronously and cooperatively. The required synchronization accuracy varies depending on the speed of the first robotic arm 101's movement.

[0037] The control unit 10 sends a motion instruction signal to the first robotic arm 101 from the first robotic arm drive instruction unit 1, thereby rotating each joint 104 and causing the first robotic arm 101 to move. When the first robotic arm 101 moves, the control unit 10 detects the amount of motion of the first robotic arm 101. Then, based on the detected amount of motion, the control unit 10 determines the motion of the second robotic arm 102 to synchronize with the first robotic arm 101. This determination is made in the first robotic arm / second robotic arm cooperation mechanism 3. Next, the first robotic arm / second robotic arm cooperation mechanism 3 sends a motion instruction signal to the second robotic arm 102 from the second robotic arm drive instruction unit 2, thereby controlling the motion of the second robotic arm 102. At this time, the control unit 10 also detects the amount of motion of the second robotic arm 102. In this way, the control unit 10 obtains the relative position information of the first robotic arm 101 and the second robotic arm 102.

[0038] Here, in order to maintain a certain distance between the front end of the first robotic arm 101 and the front end of the second robotic arm 102, the angle of the joint 104 of the first robotic arm 101 is controlled by the first robotic arm drive indicator 1 included in the control unit 10, and the angle of the joint 104 of the second robotic arm 102 is controlled by the second robotic arm drive indicator 2 included in the control unit 10. If the control unit 10 detects a significant increase in the aforementioned amount of motion, indicating that the distance between the front end of the first robotic arm 101 and the front end of the second robotic arm 102 cannot be maintained within a certain range, the control unit 10 stops the respective movements of the first robotic arm 101 and the second robotic arm 102, and displays a warning on the display unit (not shown) connected to the control unit.

[0039] The angle of joint 104 is detected by the control unit 10 via an encoder. An encoder is a device used to detect the position (angle) of the rotating shaft of a motor. Because of the encoder, the control unit 10 can identify how much and in which direction the robotic arm has moved. For example, in an optical encoder, a circular plate is mounted on the rotating shaft of the motor, and slits through which light passes are regularly arranged on the plate. Light-emitting diodes and light-receiving elements (photodiodes) that determine the intensity of the light are arranged at positions separated by the slits. The control unit 10 can detect the rotation angle of joint 104 based on the rotation direction of the motor and the number of times the light-receiving element receives light from the slits. Signal cables for transmitting signals between the control unit 10 and joint 104 and power cables for actuating joint 104 are built into the front end of the first robotic arm 101 and the respective arms 105 of the second robotic arm 102. The control unit 10 has a storage unit connected to it (see reference...). Figure 5 The length of arm 105 is stored in the storage unit 8). Based on the length of arm 105 and the angle of joint 104, the control unit 10 can calculate and identify the position of the front end of the first robotic arm 101 and the second robotic arm 102 respectively.

[0040] In order to maintain a certain distance between the front end of the first robotic arm 101 and the front end of the second robotic arm 102, for example, the storage unit stores a reference distance, and the control unit 10 controls the position of the front end of the second robotic arm 102 so that the distance between the front end of the first robotic arm 101 and the front end of the second robotic arm 102 converges within a certain range (e.g., ± tens of centimeters) from the reference distance.

[0041] In addition, in order to maintain a certain distance between the front end of the first robotic arm 101 and the front end of the second robotic arm 102, for example, the storage unit stores the lower limit and the upper limit of the distance, and controls the position of the front end of the second robotic arm 102 so that the distance is not outside the range of the lower limit or the upper limit.

[0042] Within the aforementioned range of a certain distance, the lower limit is determined by considering the length that will not exert excessive tension on the cable 107, and the upper limit is determined by considering the length of the cable 107 that would be too long and hooked onto other parts.

[0043] Furthermore, while the connection between cable 107 and power supply 109 has been described here, cable 107 may also be connected to any control unit in a computer system or similar device without being connected to power supply 109. That is, cable 107 may also be a signal cable used to transmit signals, where the signal is used by the front-end device 106 for processing such as inspection.

[0044] Furthermore, while the implementation of automatic inspection has been described here, the robot mechanism of the present invention is not limited to the purpose of automatic inspection, and can also be used for purposes such as photography, processing, assembly, welding, painting, sorting, or conveying. Depending on these applications, the front end device of the first robotic arm uses equipment for performing processes such as inspection, photography, processing, assembly, welding, painting, sorting, or conveying.

[0045] In addition, Figure 1 In the process, the first robotic arm 101 and the second robotic arm 102 are suspended below the support body 103, but these robotic arms and the object to be inspected 108 can also be configured on the support body.

[0046] <Effects of the Implementation Method>

[0047] In the robot mechanism of this embodiment, a control unit is provided that can control the movement of the front end of the first robotic arm. Based on the movement of the front end of the first robotic arm, the control unit controls the position of the front end of another second robotic arm that holds the cable extending from the front end device of the first robotic arm. At this time, the control unit controls the distance between the front ends of the two robotic arms to be constant (within a certain range), thereby providing a robot mechanism that can prevent cable breakage and avoid the cable from contacting the object being inspected and assembled.

[0048] That is, in this embodiment, since the cable of the front end device of the first robotic arm is not allowed to run along the structure of the first robotic arm, the presence of the cable is disregarded, allowing the first robotic arm to move freely. Furthermore, this prevents the cable from getting caught in the first robotic arm and also prevents it from snagling on the object being inspected or assembled.

[0049] Furthermore, since the position and posture of the front end of the first robotic arm can be controlled independently of cables, there is no problem even if there are multiple combinations of joint angles used to achieve the position and posture of the front end of the first robotic arm. That is, redundancy can be ensured. By ensuring redundancy, the path between the via points of the front end of the first robotic arm can be selected more freely, and the motion procedure of the first robotic arm can be simplified.

[0050] Furthermore, since the shape of the cable along the first robotic arm does not need to be considered, the effort required for cable length adjustment and slack management can be saved. In other words, the time required for motion setting and motion verification of the first robotic arm can be shortened.

[0051] Thus, according to this embodiment, a robot mechanism capable of suppressing the restriction of the cable on the movement of the robotic arm can be provided.

[0052] <Variation Example 1>

[0053] Figure 2 It means to Figure 1 A schematic diagram of the structure of the automatic inspection device, where the second robotic arm 102 is replaced by a single-axis robot 110 and a single-axis slider 111. The single-axis slider 111 is a connection that connects the single-axis robot 110, which serves as the second robotic arm, to the support body 103. The first robotic arm 101 is fixed to the single-axis slider 111, which is supported in a manner that allows it to slide relative to the support body 103 in one direction. That is, the single-axis robot 110 and the single-axis slider 111 slide only in a single-axis direction along the surface of the support body 103 that supports the single-axis slider 111. The single-axis slider 111 slides, for example, along a track provided on the support body 103. The single-axis robot 110 does not have joints.

[0054] In this modified example, when the first robotic arm 101 is moved, the control unit 10 detects the amount of movement of the first robotic arm 101. Then, the control unit 10 controls the position of the single-axis slider 111 based on the detected amount of movement. That is, in order to maintain a certain distance between the front end of the first robotic arm 101 and the front end of the single-axis robot 110, the angle of the joint 104 of the first robotic arm 101 is indicated by the first robotic arm drive indicator 1 included in the control unit 10, and the position of the single-axis robot 110 is controlled by the second robotic arm drive indicator 2 included in the control unit 10.

[0055] In this variation, it is possible to obtain the use Figure 1 The effect described is illustrated. Furthermore, in this modified example, since a simple robotic arm without joints (single-axis robot 110) is used, redundancy of the first robotic arm 101 can be ensured. The jointless single-axis robot 110 is inexpensive to manufacture and also helps to reduce costs.

[0056] <Variation Example 2>

[0057] Figure 3 It means in Figure 1 A schematic diagram of the structure in the automatic inspection device, showing the addition of a cable winding mechanism (winding section) 112 to the front end of the second robotic arm 102. Apart from the inclusion of the winding mechanism 112, the structures of the first robotic arm 101 and the second robotic arm 102 are similar. Figure 1 same.

[0058] When the first robotic arm 101 is moved, the control unit 10 detects the amount of movement of the first robotic arm 101. Then, the control unit 10 controls the movement of the second robotic arm 102 based on the detected amount of movement. That is, in order to maintain a certain distance between the front end of the first robotic arm 101 and the front end of the second robotic arm 102, the angle of the joint 104 of the first robotic arm 101 is indicated by the first robotic arm drive indicator 1 included in the control unit 10, and the angle of the joint 104 of the second robotic arm 102 is controlled by the second robotic arm drive indicator 2 included in the control unit 10.

[0059] Furthermore, the control unit 10 adjusts the winding and unwinding amounts of the cable by the cable winding mechanism 112. When the front end of the first robotic arm 101 is far from the front end of the second robotic arm 102, the cable winding mechanism 112 unwinds the cable 107 to increase the length of the cable 107 between the front end device 106 and the cable winding mechanism 112. When the front end of the first robotic arm 101 is close to the front end of the second robotic arm 102, the cable winding mechanism 112 winds the cable to reduce the length of the cable 107.

[0060] Through this action, the first robotic arm / second robotic arm collaboration mechanism 3 included in the control unit 10 adjusts to ensure that the slack of the cable 107 does not exceed the predetermined range. In this modified example, in addition to using Figure 1 In addition to the effects described, the cable winding mechanism 112 can also adjust the amount of cable released (winding amount), thus increasing the degree of freedom in the distance between the front end of the first robotic arm 101 and the front end of the second robotic arm 102.

[0061] <Variation Example 3>

[0062] Figure 4 It means in Figure 1 In the automatic inspection device, a schematic diagram of the structure of the control unit 10 is added, showing the three-dimensional data 4 of the inspection object and the inspection device, and the three-dimensional data 5 of the motion prohibition area. Furthermore, the inspection object 108 has a three-dimensional protrusion. Additionally, the construction of the first robotic arm 101 and the second robotic arm 102 is similar to... Figure 1 same.

[0063] When the first robotic arm 101 is moved, the control unit 10 detects the amount of movement of the first robotic arm 101. Then, the control unit 10 controls the movement of the second robotic arm 102 based on the detected amount of movement. That is, in order to maintain a certain distance between the front end of the first robotic arm 101 and the front end of the second robotic arm 102, the angle of the joint 104 of the first robotic arm 101 is indicated by the first robotic arm drive indicator 1 included in the control unit 10, and the angle of the joint 104 of the second robotic arm 102 is controlled by the second robotic arm drive indicator 2 included in the control unit 10.

[0064] Here, the control unit 10 includes three-dimensional data 4 of the inspection object and the inspection device. The three-dimensional data 4 of the inspection object and the inspection device includes at least the three-dimensional data of the inspection object 108, the first robotic arm 101, the second robotic arm 102, and the support 103. Using the three-dimensional data 4 of the inspection object and the inspection device, the control unit 10 generates and maintains at least three-dimensional data 5 of the three-dimensional areas (hereinafter referred to as the motion prohibition areas) of the joints 104 and arms 105 of the first robotic arm 101, the front-end device 106, the joints 104 and arms 105 of the second robotic arm 102, where they cannot exist. The three-dimensional data 4 of the inspection object and the inspection device and the three-dimensional data 5 of the motion prohibition areas are stored, for example, in the storage unit described above.

[0065] Then, the control unit 10 issues instructions such that at least the joints 104 and 105 of the first robotic arm 101, the front-end device 106, and the joints 104 and 105 of the second robotic arm 102 do not enter the restricted movement area. That is, the first robotic arm drive indicator 1 indicates the angle of the joints 104 of the first robotic arm 101, and the second robotic arm drive indicator 2 indicates the angle of the joints 104 of the second robotic arm 102.

[0066] In this variation, besides using Figure 1 In addition to the explanatory functions, it is also possible to set motion prohibition zones, thus enabling the generation of robotic arm motion programs even when the shape or movement of the object being inspected is complex. Furthermore, by setting areas such as the sides of the object being inspected, where there is a high possibility of contact with the robotic arms, motion prohibition zones can be defined, preventing contact between the robotic arms and the object being inspected, and ensuring safe inspection.

[0067] <Variation Example 4>

[0068] Figure 5 It means in Figure 1 The automatic inspection device includes a schematic diagram of a structure in which a function 6 for estimating cable deformation and a function 7 for selecting setting conditions for the second robotic arm joint so that the cable deformation is below a reference value are added to the control unit 10. Additionally, a storage unit 8 is connected to the control unit 10. Furthermore, the structures of the first robotic arm 101 and the second robotic arm 102 are similar to... Figure 1 same.

[0069] When the first robotic arm 101 is moved, the control unit 10 detects the amount of movement of the first robotic arm 101. Then, the control unit 10 controls the movement of the second robotic arm 102 based on the detected amount of movement. That is, in order to maintain a certain distance between the front end of the first robotic arm 101 and the front end of the second robotic arm 102, the angle of the joint 104 of the first robotic arm 101 is indicated by the first robotic arm drive indicator 1 included in the control unit 10, and the angle of the joint 104 of the second robotic arm 102 is controlled by the second robotic arm drive indicator 2 included in the control unit 10.

[0070] In the control unit 10, based on the position and posture of the front end device 106 at the front end of the first robotic arm 101, the required cable length between the front end of the first robotic arm 101 and the front end of the second robotic arm 102 is estimated, and the cable deformation (bending amount) is also estimated. Thus, the control unit 10 has the function of estimating the cable deformation amount 6.

[0071] Then, the control unit 10 controls the angle of the joint 104 of the second robotic arm 102 so that the amount of cable deformation is below a reference value. Here, the storage unit 8 stores multiple setting conditions for the joint 104 of the second robotic arm 102. In this control, the control unit 10 selects the setting condition of the second robotic arm joint that makes the amount of cable deformation below a reference value from the setting conditions of the joint 104 stored in the storage unit 8 by selecting the function 7 that makes the amount of cable deformation below a reference value, and instructs the joint 104 of the second robotic arm 102 accordingly.

[0072] In this variation, besides using Figure 1 In addition to the effects described, the amount of cable deformation can also be taken into account to enable the second robotic arm 102 to move, thus enabling the setting of the motion program of the first robotic arm 101 in a shorter time.

[0073] The invention described above is based on specific embodiments and is carried out by the inventors of the present invention. However, the present invention is not limited to the above embodiments and various modifications can be made without departing from its spirit.

[0074] Industrial applications

[0075] This invention can be widely applied to robotic mechanisms.

[0076] Explanation of reference numerals in the attached figures

[0077] 1. First robotic arm drive indicator

[0078] 2. Second robotic arm drive indicator

[0079] 3. First robotic arm / second robotic arm collaborative mechanism

[0080] 4. Three-dimensional data of the inspection object and inspection device

[0081] 5. Three-dimensional data of the prohibited action area

[0082] 6. Function to estimate cable deformation

[0083] 7. Select the setting conditions for the second robotic arm joint so that the cable deformation is below the reference value.

[0084] 8 Storage Units

[0085] 10 Control Department

[0086] 101 First Robotic Arm

[0087] 102 Second Robotic Arm

[0088] 103 Support Body

[0089] 104 joints

[0090] 105 arms

[0091] 106 front-end devices

[0092] 107 cable

[0093] 108 Inspection Targets

[0094] 109 power supply

[0095] 110 Single-Axis Robot

[0096] 111 Single-axis slider

[0097] 112 Cable winding mechanism

[0098] 120 straps.

Claims

1. A robot mechanism, characterized in that, have: The first robotic arm is supported by a support body and has joints; The second robotic arm is supported by the support body; A front-end device is disposed at the front end of the first robotic arm; A cable, which is arranged along the second robotic arm, is connected to the front-end device via the front end of the second robotic arm; as well as The control unit controls the movement of the front end of the second robotic arm based on the movement of the first robotic arm.

2. The robot mechanism according to claim 1, characterized in that, The second robotic arm has one or more joints.

3. The robot mechanism according to claim 1, characterized in that, The second robotic arm and the connection between the second robotic arm and the support body are configured to slide on the support body.

4. The robot mechanism according to claim 3, characterized in that, The second robotic arm does not have joints.

5. The robot mechanism according to claim 1, characterized in that, The robotic mechanism also has a winding section disposed at the front end of the second robotic arm for winding the cable.

6. The robot mechanism according to claim 1, characterized in that, The first robotic arm uses the front-end device to handle objects. The control unit controls the movement of the front end of the second robotic arm based on the three-dimensional data of the object and the robot mechanism.

7. The robot mechanism according to claim 1, characterized in that, The robot mechanism also includes a storage unit connected to the control unit. The storage unit stores multiple setting conditions for the joints of the second robotic arm. The control unit selects the set conditions so that the deformation of the cable is below the reference value.

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