Robot arm and unmanned aerial vehicle equipped therewith

Abstract

To find a more practical configuration for a robot arm whose fixed end has an unstable position or posture.SOLUTION: The invention provides a robot arm and an unmanned aerial vehicle equipped therewith. The robot arm comprises multiple joints, and performs: a displacement operation that changes the position and posture of a tip, which is a free end, to a desired position and posture; and an arresting operation that automatically compensates for disturbances in the position or posture of the tip due to external factors. The number of joints used in the arresting operation is smaller than the number of joints used in the displacement operation. All or some of the joints used in the arresting operation are also used in the displacement operation.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to robot arm technology. [Background technology]

[0002] The following Patent Document 1 discloses an unmanned aerial vehicle equipped with a robot arm having multiple joints. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2018-34284 Summary of the Invention [Problem to be solved by the invention]

[0004] Unlike general industrial robot arms, robot arms mounted on moving objects such as unmanned aerial vehicles change the position and posture of their fixed ends in accordance with the movement of the moving object. When performing work with such a robot arm, it is possible to reduce disturbances in the position and posture of the hand by moving the hand of the robot arm in the opposite direction to the unintended movement of the moving object. However, such counteracting movements increase the amount of calculations required for kinematic calculations and motion planning as the number of joints in the arm increases, reducing the real-time nature (responsiveness) of the operation.

[0005] In addition, the longer the overall length of a robot arm, the greater the torque and reduction ratio of each joint must be, and the greater the moment of inertia when the arm is moved. The weight and moment of inertia of a robot arm mounted on an unmanned aerial vehicle are directly related to the flight stability and flight time. For this reason, particularly strict constraints are imposed on the weight and operation of robot arms mounted on unmanned aerial vehicles.

[0006] In view of the above circumstances, the problem that the present invention aims to solve is to find a more practical configuration for a robot arm whose fixed end has an unstable position and orientation. [Means for solving the problem]

[0007] In order to solve the above problems, the robot arm of the present invention has a plurality of joints and performs a displacement movement to change the free end, i.e., the hand, to a desired position and posture, and a stationary movement to automatically correct any disturbance in the position or posture of the hand caused by external factors, wherein the number of joints used for the stationary movement is less than the number of joints used for the displacement movement, and all or some of the joints used for the stationary movement are also used for the displacement movement.

[0008] In the present invention, among the multiple joints of the robot arm, the joints used when actively changing the position and posture of the hand are functionally separated from the joints used when correcting unintended positional deviations and posture disturbances of the hand. This separates the problem of the range of motion and flexibility of motion (richness of motion patterns) of the arm from the problem of stability of the hand. More specifically, by using more joints for displacement motion than for stationary motion, including some or all of the joints used for stationary motion, the range of motion and flexibility of motion of the arm can be maximized, while the stability of the hand can be kept to the minimum required performance depending on the instability of the fixed end and the required stationary accuracy. In other words, it becomes possible to realistically and practically optimize the amount of calculation and reaction speed without narrowing the types of tasks that the robot arm can perform.

[0009] In this case, the robot arm of the present invention preferably has six or more joints, which enables the robot arm of the present invention to perform the same types of work as a general industrial robot arm, making it possible to use the robot arm of the present invention in a more versatile manner.

[0010] In addition, in the robot arm of the present invention, it is preferable that the three joints that rotate around the roll axis, the pitch axis, and the yaw axis are used for the stationary motion. By using joints that rotate around three mutually orthogonal axes for the stationary motion, it becomes possible to keep the posture and direction of the hand constant.

[0011] In this case, the three joints are preferably the three joints closest to the hand. It is desirable for the resting motion to respond immediately to disturbances in the position or posture of the hand, that is, to immediately eliminate the disturbances. By using the three joints closest to the hand for the resting motion, the moment of inertia can be suppressed, making it possible to perform the resting motion more quickly.

[0012] Moreover, it is preferable that the robot arm of the present invention includes a first inertial measurement unit that is an inertial measurement unit arranged at or near the hand, at least some of the joints are provided with encoders that detect the angular positions of these joints, and the angular positions of the joints used in the stationary motion are detected by the first inertial measurement unit. In determining the angular position of each joint, the number of encoders required can be reduced by specifying the range that can be calculated from the output value of the inertial measurement unit.

[0013] In the robot arm of the present invention, it is preferable that the drive source of at least some of the joints is a motor equipped with a reduction mechanism, and that the reduction mechanism uses a strain wave gear. By using a strain wave gear device as the reduction mechanism of the motor, it is possible to realize highly accurate operation with reduced backlash.

[0014] In addition, the robot arm of the present invention is preferably equipped with a detection means capable of identifying the position of the workpiece to be worked on, so that the operator of the robot arm and the control program can perform work more accurately and reliably based on the position information of the workpiece.

[0015] In addition, in order to solve the above problems, the unmanned aerial vehicle of the present invention is characterized by comprising a flight unit, which is an aircraft equipped with multiple rotors, and the robot arm of the present invention.

[0016] The advantages of the robot arm of the present invention are as described above. By combining this robot arm with a flight unit, it becomes possible to perform various tasks in the air while suppressing shaking of the hand caused by the swinging of the flight unit, etc.

[0017] In this case, the unmanned aerial vehicle of the present invention preferably includes a first inertial measurement unit that is an inertial measurement unit arranged at or near the hand, and a second inertial measurement unit that is an inertial measurement unit arranged at the flight unit or at the fixed end of the robot arm. This makes it possible, for example, to detect the angular positions of each joint for stationary operation with the first inertial measurement unit and to detect the positional deviation and tilt of the flight unit with the second inertial measurement unit, thereby further improving the operational accuracy of the robot arm.

[0018] In this case, the second inertial measurement unit is preferably a different inertial measurement unit from the inertial measurement unit used by the flight unit for its attitude control. In general, flight units such as multicopters are equipped with an inertial measurement unit for its attitude control. By providing the second inertial measurement unit separately, it becomes possible to select, arrange, and use the second inertial measurement unit more purposefully, regardless of the constraints on using the inertial measurement unit for the attitude control of the flight unit.

[0019] In this case, the second inertial measurement unit is preferably installed on the fixed end of the flying unit or the robot arm without any vibration-isolating material. The inertial measurement unit provided in the flying unit for its attitude control is generally attached to the flying unit via a vibration-isolating material in order to reduce vibration noise of the aircraft. By providing the second inertial measurement unit separately from the inertial measurement unit and installing it without any vibration-isolating material, it becomes possible to grasp the actual state of the aircraft more accurately. Effect of the Invention

[0020] As described above, the robot arm and unmanned aerial vehicle equipped with the robot arm of the present invention can further enhance the practicality of a robot arm whose fixed end has an unstable position and posture. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a perspective view showing an example of a robot arm of the present invention. [Diagram 2] 1 is a schematic diagram showing an example of an unmanned aerial vehicle of the present invention. [Diagram 3] 5A to 5C are schematic diagrams showing a displacement operation of a robot arm according to the embodiment. [Figure 4] 1A to 1C are schematic diagrams illustrating a stationary operation of a robot arm according to an embodiment. [Diagram 5] 5 is a schematic diagram showing another aspect of the stationary motion shown in FIG. 4. [Figure 6] FIG. 2 is a block diagram showing the functional configuration of a multicopter according to an embodiment. [Figure 7] FIG. 13 is a schematic diagram showing a modified example of a multicopter according to an embodiment. [Figure 8] FIG. 13 is a schematic diagram showing another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The embodiment described below is an example of an unmanned aerial vehicle equipped with a robot arm of the present invention.

[0023] <Robot arm configuration> 1 is a perspective view of a robot arm 20 according to the present embodiment. Hereinafter, the basic configuration of the robot arm 20 will be described with reference to FIG.

[0024] The robot arm 20 of this embodiment is a multi-joint manipulator arm having six joints (degrees of freedom) J1-J6, and a gripper 61 serving as an end effector is attached to its tip (free end). As will be described in detail later, the robot arm 20 actively changes the position and posture of the gripper 61 using all of the joints J1-J6, and corrects unintended positional deviations and disturbances in posture of the gripper 61 using only the three joints J4-J6 on the tip side. This allows the amount of calculation and reaction speed to be adjusted to a realistic and practically acceptable level without narrowing the types of tasks that the robot arm 20 can perform.

[0025] The relationship between each joint of the robot arm 20 and its rotation direction and pivot direction is as follows: J1: Yo J2: Pitch J3: Pitch J4: Yo J5: Roll J6: Yo

[0026] Of these, joint J1 is the joint located closest to the fixed end, and joint J6 is the joint located closest to the hand. The coordinate axes Y, P, and R shown in FIG. 1 represent the directions of the yaw axis, pitch axis, and roll axis, respectively. The robot arm 20 is formed by link members 50 successively connected by these joints J1-J6. In addition, a flange-shaped joint 51 that is fixed to the flight unit 10, which will be described later, is provided at the fixed end of the robot arm 20.

[0027] Each of the joints J1-J6 (hereinafter, the joints J1-J6 are also collectively referred to as "joints J") has a motor 41 as a drive source and a strain wave gear device 42 as a reduction mechanism thereof. For example, in a commercially available three-axis stabilizer for a camera (so-called camera gimbal), a configuration is widely adopted in which three link members rotating around a roll axis, a pitch axis, and a yaw axis are connected and these link members are directly driven by a brushless motor. Such a stabilizer is mainly intended to correct camera shake during shooting, and the distance between the center of gravity of the payload and each joint is basically constant. In other words, the distance between any of the joints and the center of gravity does not approach or move away. Furthermore, the weight of the payload does not increase or decrease during operation. On the other hand, in the robot arm 20 of this embodiment, the positional relationship between its center of gravity and each joint J changes fluidly during operation. Furthermore, when the end effector is a gripper 61 as in this embodiment, the weight of the workpiece 69 that it grips also becomes a load on each joint J. In the robot arm 20 of this embodiment, a speed reduction mechanism is provided at each joint J, so that the robot arm 20 can maintain stable operation despite its own weight, movement of the center of gravity, and fluctuations in weight.

[0028] As described above, in each joint J in this embodiment, a strain wave gear device 42 is employed as a reduction mechanism for the motor 41. The strain wave gear device 42 is a reduction mechanism using a strain wave gear. Due to its operating principle, strain wave gears do not require backlash and have excellent operating precision. In addition, the number of parts is small and a large reduction ratio can be obtained in one stage. In particular, in a mechanism in which a relatively large number of joints J are connected in series, such as the robot arm 20 in this embodiment, the accumulated error due to backlash cannot be ignored. The effect becomes more pronounced as the number of joints increases.

[0029] The robot arm 20 of this embodiment employs strain wave gear devices 42 in all of its joints J, thereby improving the operational accuracy of the robot arm 20 and achieving a reduction in size and weight of the joint structure. The drive mechanism for the joints J is not limited to that of this embodiment, and strain wave gear devices 42 may be employed only in the joints J closer to the fixed end, or a reduction mechanism simpler than the strain wave gear device 42 may be employed, depending on the weight, number of joints, and required operational accuracy. Alternatively, if the robot arm 20 is sufficiently small and lightweight, it is also possible to directly drive each joint J with a motor 41.

[0030] Although the gripper 61 also has link members and joints that form its claws, a motor that is a driving source, etc., the gripper 61 is merely an example of an end effector. Therefore, a detailed description of the gripper 61 will be omitted. The gripper 61 may be replaced with any end effector, such as a sensor such as a camera, a welding device, a painting device, a suction device, a tapping inspection hammer, or other tools, depending on the application of the robot arm 20.

[0031] <Robot arm movement> Fig. 2 is a schematic diagram of a multicopter 91 which is an unmanned aerial vehicle of this embodiment. Fig. 3 is a schematic diagram showing a displacement operation of the robot arm 20. Fig. 4 is a schematic diagram showing a stationary operation of the robot arm 20. Fig. 5 is a schematic diagram showing another aspect of the stationary operation shown in Fig. 4. Hereinafter, the displacement operation and stationary operation of the robot arm 20 will be described with reference to Figs. 2 to 5.

[0032] The multicopter 91 of this embodiment includes a flight unit 10 capable of flying in the air with multiple rotors (horizontal propellers), and the robot arm 20 is connected to its underside. As described above, the robot arm 20 performs a displacement operation (FIG. 3) for changing the gripper 61 to a desired position and posture, and a rest operation (FIGS. 4 and 5) for automatically correcting any disturbance in the position or posture of the gripper 61.

[0033] Here, the "displacement operation" refers to an operation in which the position and attitude of the gripper 61 are intentionally and actively changed from the current position and attitude, for example, by a control signal from an operator or automatically by a program (firmware or application) of the robot arm 20. For example, it is an operation in which the gripper 61 is moved to the position of the workpiece 69 and the attitude of the gripper 61 is changed so that it can grip the workpiece.

[0034] The robot arm 20 of this embodiment performs a displacement operation using all of its joints J. Therefore, as the number of joints J of the robot arm 20 increases, the range of motion in the displacement operation becomes wider and the flexibility of the operation also improves. The robot arm 20 of this embodiment has six joints J and can perform the same operations in the air as a general industrial robot arm. On the other hand, when versatility is not required for the robot arm 20 and it is to be used only for predetermined simple operations, it is also possible to conversely reduce the number of joints.

[0035] The "static operation" is an operation for automatically correcting disturbance in the position or posture of the gripper 61 due to an external cause. The term "external cause" here has the literal meaning, and refers to a cause that is outside the robot arm 20, such as the rocking of the flight unit 10 or the tilt of the flight unit 10 when maintaining its position against a crosswind, for example, in relation to disturbance in the position or posture of the gripper 61.

[0036] As for the stationary operation, for example, as shown in FIG. 4, the robot arm 20 tries to keep both the current position and the current attitude of the gripper 61 constant in response to disturbances in the position and attitude of the flying unit 10, and other modes as shown in FIG. 5 are conceivable. In the example of FIG. 5, for convenience of explanation, the end effector is replaced by a camera 62 instead of the gripper 61. As other modes of stationary operation, for example, as shown in FIG. 5(a), an operation of keeping the direction of the camera 62 at one point, that is, an operation of controlling the relative orientation of the camera 62 to one point so that the camera 62 always faces one point in space (here, the workpiece 69 to be photographed), or an operation of keeping the attitude of the camera 62 constant, that is, an operation of controlling the absolute attitude of the camera 62 in space to be constant, regardless of the position of the workpiece 69, are conceivable.

[0037] Moreover, the robot arm 20 of this embodiment performs stationary motion using the three joints J4-J6, which are the joints closest to the hand tip. These joints J4-J6 are joints that rotate around the yaw axis, roll axis, and pitch axis, which are three axes perpendicular to each other. In other words, these joints J4-J6 cannot completely offset the positional deviation of the gripper 61, but at least the absolute posture of the gripper 61 and the relative orientation with respect to the workpiece 69 can be kept constant in theory. The robot arm 20 of this embodiment offsets the positional deviation of the gripper 61 by moving the gripper 61 in the opposite direction to the possible extent while keeping the orientation or posture of the gripper 61 constant.

[0038] Here, it is desirable for the stationary motion to immediately respond to disturbances in the position and posture of the gripper 61, that is, to immediately resolve the disturbances. On the other hand, as the number of joints in the robot arm 20 increases, the amount of calculation required for kinematic calculations and motion planning increases, and the real-time nature of the stationary motion decreases. In this embodiment, the robot arm 20 uses only the three joints J4-J6 closest to the hand tip for stationary motion, thereby reducing the moment of inertia and achieving rapid stationary motion. On the other hand, if there are no particular concerns about the influence of the moment of inertia, delays in calculation processing, gimbal lock, etc., it is also possible to use joints on the fixed end side or non-contiguous joints for stationary motion.

[0039] It should be noted that the joints used for stationary motion do not always have to include the three joints that rotate around the roll axis, pitch axis, and yaw axis. For example, when stationary motion using joints J4-J6 cannot be processed in real time, it may be possible to improve the overall work accuracy by performing stationary motion using only two of these three axes (two joints). Conversely, if there is room for processing capacity for stationary motion, the number of joints used for stationary motion may be increased to widen the range in which positional deviations can be offset.

[0040] In this manner, the robot arm 20 of this embodiment has six joints J, and the joints (joints J1-J6) used when actively changing the position and posture of the gripper 61 are functionally separated from the joints (joints J4-J6) used when correcting an unintended positional shift or posture disturbance of the gripper 61. This separates the problem of the range of motion and flexibility of the motion of the robot arm 20 from the problem of the stability of the gripper 61. More specifically, the displacement motion of the robot arm 20 uses more joints than the stationary motion, including all the joints J4-J6 used in the stationary motion, thereby maximizing the range of motion and flexibility of the motion of the robot arm 20, while the stability of the gripper 61 is adjusted to a degree that at least its posture and orientation can be maintained. In other words, the same joints and algorithms as those for the displacement motion are not diverted to the stationary motion, but the balance is optimized by defining them separately.

[0041] The total number of joints J of the robot arm 20 and the number of joints J used in the displacement operation are not limited to six joints in this embodiment, and various numbers of joints can be considered depending on the range of motion and flexibility of the operation required for the application. The number of joints J used by the robot arm 20 in the stationary operation is also not limited to three joints in this embodiment, and various numbers of joints can be used depending on the required stability of the hand. The minimum configuration of the robot arm of the present invention is a configuration in which the displacement operation is performed by two joints, one of which is also used for the stationary operation. Regardless of the configuration or form, it is possible to obtain the same effect as the robot arm 20 of this embodiment as long as the number of joints used for the stationary operation is less than the number of joints used for the displacement operation and all or a part of the joints used for the stationary operation are also used for the displacement operation. In other words, it is possible to realistically and practically optimize the amount of calculation and the reaction speed without narrowing the types of work that the robot arm can perform.

[0042] (Multicopter functional configuration) Fig. 6 is a block diagram showing the functional configuration of the multicopter 91. Hereinafter, the functional configurations of the flight unit 10 and the robot arm 20 will be described with reference to Fig. 6.

[0043] As shown in FIG. 6, the functions of the flight unit 10 in this embodiment are configured by a control device 11, which is a so-called flight controller, a plurality of rotors 15, and a communication device 16 that communicates with a pilot device 80 of an operator.

[0044] The control device 11 is a microcontroller that executes a flight control program (so-called flight software). The control device 11 is not limited to a single microcontroller, and may be combined with a so-called companion computer. In addition, it is also possible to configure it with, for example, an FPGA (field-programmable gate array) or an ASIC (application specific integrated circuit). The flight unit 10 further has an IMU (Inertial Measurement Unit) 12 (an inertial measurement device) having a three-axis acceleration sensor and a three-axis angular velocity sensor, a barometric pressure sensor 14 (an altimeter), a GPS 13 (to be precise, a receiver of a navigation satellite system), and an electronic compass 15, which are connected to the control device 11. The control device 11 obtains position information including the inclination and rotation of the aircraft, as well as the position on a horizontal plane (longitude and latitude), altitude above sea level (altitude), and the azimuth angle of the nose, using these sensors, and controls the rotation speed of each rotor 15 to fly the flight unit 10.

[0045] On the other hand, the functions of the robot arm 20 in this embodiment are mainly constituted by a control device 31, a plurality of motors 41, a gripper 61, and a communication device .

[0046] The control device 31 is also a microcontroller like the control device 11. The control device 31 drives each joint J (motor 41) while performing kinematic calculations and motion planning by its program. The control device 31 is also similar to the control device 11 in that the implementation form of the control device 31 is not limited to a microcontroller. The robot arm 20 further has two inertial measurement units, an IMU 32 (first inertial measurement unit) and an IMU 33 (second inertial measurement unit), each having a three-axis acceleration sensor and a three-axis angular velocity sensor, and an encoder 34 that detects the angular positions of the joints J1-J3, which are connected to the control device 31. The control device 31 grasps the state of each part of the robot arm 20 by using these sensors, and controls each motor 41 to perform the displacement and stationary operation of the robot arm 20.

[0047] In this embodiment, IMU 32 is disposed in a non-moving portion of gripper 61, and IMU 33 is disposed inside flight unit 10. That is, IMUs are disposed at the base and tip of robot arm 20. IMU 32 is used to detect the angular positions of each of joints J4-J6 that perform stationary operations, and IMU 33 is used to detect positional deviation and tilt of flight unit 10.

[0048] In the robot arm 20 of this embodiment, an encoder 34 is provided in the link drive section (final output section after decelerating the rotation of the motor 41) of the joints J1-J3. The control device 31 specifies the angular positions of the joints J1-J3 from the output value of the encoder 34, and specifies the angular positions of the joints J4-J6 from the output value of the IMU 32. In the robot arm 20 of this embodiment, when grasping the angular position of each joint J, the IMU 32 specifies the range that can be calculated from the output value of the IMU 32, thereby reducing the number of encoders 34 required. When starting up, the robot arm 20 of this embodiment first calibrates the joints J1-J3 and automatically initializes the angular positions of the joints J1-J3, then specifies the states of the joints J4-J6 from the output value of the IMU 32, and automatically initializes these angular positions. Note that the method of specifying the angular positions of each joint J is not limited to that of this embodiment, and for example, it is possible to specify the angular positions of all joints by encoders, and it is also possible to specify them by an IMU. Alternatively, each joint may be initialized manually.

[0049] As shown in Fig. 6, the IMU 33 installed in the flight unit 10 is a separate inertial measurement device from the IMU 12 used by the flight unit 10 for its attitude control. In general, flight units such as multicopters are equipped with an inertial measurement device for its attitude control. In this embodiment, the IMU 33 installed on the flight unit 10 side is prepared separately from the IMU 12 of the flight unit 10, so that the IMU 33 can be selected, arranged, and used more purposefully, regardless of the constraints on using the IMU for attitude control of the flight unit 10.

[0050] In addition, the IMU 33 in this embodiment is installed in the flight unit 10 without any vibration-isolating material. The "vibration-isolating material" here refers to a cushioning material or vibration absorbing material using, for example, rubber or foam material. In general, the inertial measurement device that the flight unit has for its attitude control is installed on the aircraft via a vibration-isolating material in order to perform stationary operation. In this embodiment, the IMU 12 is also installed in the flight unit 10 via a vibration-isolating material. This reduces the vibration noise detected by the IMU 12, and the output value of the IMU 12 becomes more suitable for the attitude control of the flight unit 10. On the other hand, the robot arm 20 has a distance between its fixed end and the hand, and even a slight tilt of the fixed end (i.e., a slight tilt of the flight unit 10) has a large effect on the hand. Therefore, in this embodiment, an IMU 33 is provided in addition to the IMU 12 of the flight unit 10, and this is installed in the flight unit 10 without any vibration-isolating material, thereby more accurately grasping the tilt of the flight unit 10. Furthermore, IMU 33 only needs to be placed in a position where it can directly acquire the attitude of flight unit 10, and it may be installed outside flight unit 10, for example, at joint 51 of robot arm 20.

[0051] In this way, the multicopter 91 of this embodiment combines a flying unit 10 that flies with multiple rotors 15 with a robot arm 20, and is thus able to perform various tasks in the air while suppressing shaking of the gripper 61 caused by the swaying of the flying unit 10, etc.

[0052] In addition, as shown in FIG. 6, in the multicopter 91 of this embodiment, the flight unit 10 and the robot arm 20 are functionally independent of each other. As described above, the IMU 33 may be installed at the joint 51 of the robot arm 20, not in the flight unit 10. In other words, the robot arm 20 does not depend on the flight unit 10 for its operation, and changing the flight unit 10 to a flight unit with a different functional configuration does not affect the operation of the robot arm 20. This means that the robot arm 20 can be applied to other flight units and other moving bodies that move on land or water. In other words, the robot arm 20 can be applied to any moving body as long as the position and attitude of the fixed end are unstable. On the other hand, by designing the robot arm 20 and the flight unit 10 as an inseparable unit, it is also possible to improve the overall structural efficiency and cost efficiency.

[0053] <Modifications and other embodiments> 7 and 8 are schematic diagrams showing modified examples of a multicopter 91. Fig. 7 is a schematic diagram showing a configuration in which a separate camera 70 is provided outside the aircraft. Fig. 8 is a schematic diagram showing an example of a land moving body 92 equipped with a robot arm 20. Below, modified examples and other embodiments of the multicopter 91 will be described with reference to Figs. 7 and 8.

[0054] The multicopter 91a in FIG. 7 is equipped with a camera 70 that identifies the position of the gripper 61 or the workpiece 69 that is the object of the gripper. The camera 70 may be a camera 70 with a light (illumination device). This allows the operator or program of the robot arm 20 to perform work more accurately and reliably based on visual information. The camera 70 in this embodiment is a so-called depth camera. As a means for detecting the position of the workpiece 69, in addition to the depth camera, for example, a general visible light camera, a stereo camera, an infrared sensor, an ultrasonic sensor, a laser scanner, an LRF (Laser Rangefinder), a millimeter wave radar, a LiDAR (Light Detection And Ranging), and combinations thereof are possible.

[0055] In the above embodiment, the robot arm 20 is combined with the flying unit 10, but the robot arm 20 can be applied not only to flying bodies, but also to moving bodies that move on land or water. For example, the land moving unit 19 equipped to the land moving body 92 shown in Fig. 8 may be, for example, a vehicle or a bipedal or quadrupedal robot. Even when the robot arm 20 is applied to such a land moving unit 19, the amount of calculation and reaction speed can be realistically and practically optimized without narrowing the types of tasks that the robot arm 20 can perform.

[0056] Although the embodiment of the present invention has been described above, the scope of the present invention is not limited to this, and various modifications can be made without departing from the spirit of the invention. [Explanation of symbols]

[0057] 10: flight unit, 11: control device, 12: IMU, 13: GPS, 14: air pressure sensor, 15: rotor, 16: communication device, 19: ground moving unit, 20: robot arm, 31: control device, 32: IMU (first inertial measurement unit), 33: IMU (second inertial measurement unit), 34: encoder, 35: communication device, 41: motor, 42: wave gear device (reduction mechanism), J1-J6: joints, 50: link member, 51: joint, 61: gripper (hand), 62: camera, 69: workpiece, 70: camera, 80: control device, 91, 91a: multicopter (unmanned aerial vehicle), 92: ground moving body

Claims

1. With multiple joints, A displacement operation for changing the position and posture of the free end of the hand to which the end effector is attached to a desired position and posture; A stilling motion is performed to automatically correct any disturbance in the position or posture of the hand caused by an external factor; the number of the joints used for the static motion is less than the number of the joints used for the displacement motion, and at least one of the joints is used only for the displacement motion; All or a part of the joints used in the static motion are also used in the displacement motion. Robot arm.

2. With six or more joints, 2. The robot arm of claim 1.

3. The stationary motion uses three joints that rotate around a roll axis, a pitch axis, and a yaw axis.

2. The robot arm of claim 1.

4. a first inertial measurement unit that is an inertial measurement unit arranged on or near the hand; At least some of the joints are provided with encoders for detecting the angular positions of the joints; The angular position of each of the joints used in the stationary motion is sensed by the first inertial measurement unit.

2. The robot arm of claim 1.

5. At least some of the joints have a motor equipped with a reduction gear as a driving source, A wave gear is used in the reduction mechanism.

2. The robot arm of claim 1.

6. Equipped with a detection means capable of identifying the position of the workpiece to be worked on; 2. The robot arm of claim 1.

7. a flight unit that is an aircraft having a plurality of rotors; A robot arm according to any one of claims 1 to 6, unmanned aircraft.

8. A first inertial measurement unit that is an inertial measurement unit arranged on or near the hand; a second inertial measurement unit disposed on the flight unit or on a fixed end of the robot arm; The unmanned aerial vehicle according to claim 7.

9. The second inertial measurement unit is an inertial measurement unit other than the inertial measurement unit used by the flight unit for its attitude control. The unmanned aerial vehicle according to claim 8.

10. The second inertial measurement unit is installed at a fixed end of the flying unit or the robot arm without any vibration isolating material. The unmanned aerial vehicle according to claim 8.

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