Coal gangue sorting robot based on human-robot collaboration

Abstract

The application discloses a coal gangue sorting robot based on man-machine cooperation, which comprises a mechanical arm, a gripper, a skeletal frame controller and a camera. The mechanical arm is arranged on one side of a coal gangue conveying belt, and servo motors and reducers are arranged at each joint of the mechanical arm. The gripper is arranged on the free end of the mechanical arm, and a servo motor is arranged on the gripper. The skeletal frame controller is installed on a worker station, and rotary encoders are arranged at each joint of the skeletal frame controller. The rotary encoders are connected with the servo motors on the mechanical arm through pulse signals. A displacement sensor is arranged in a handle, and the displacement sensor is connected with the servo motor on the gripper through pulse signals. The camera shoots image information on the coal gangue conveying belt and transmits the image information to the worker station. By controlling the skeletal frame controller, the mechanical arm can pick and carry coal and coal gangue, which can solve the problem that the sorting accuracy of machine vision is not as good as manual experience judgment, improve the sorting efficiency and reduce the labor intensity of miners.

Description

Technical Field

[0001] This invention belongs to the field of coal washing and beneficiation technology, specifically relating to a coal gangue sorting robot based on human-machine collaboration. Background Technology

[0002] Coal mining is a high-risk industry, and the coal industry has been exploring ways to reduce the number of workers underground, lower safety risks, improve production efficiency, and reduce the labor intensity of miners. The hope is that "machine replacement" will become a reality in coal mining operations with the application of artificial intelligence technology, with gangue sorting being a typical application. Currently, some automated gangue sorting robots exist on the market, but they generally have limitations and lack flexibility. The particle size range of gangue is inconsistent, and automated sorting robots can only sort gangue within a certain particle size range, unable to complete the full range of sorting operations like humans. Using multiple machines to sort the same batch of gangue within the same particle size range significantly increases sorting costs and reduces robot efficiency, making robot sorting far more expensive than manual sorting. In other words, the accuracy of machine vision sorting is not as high as human experience-based judgment. Inaccurate gangue sorting leads to coal and gangue burning together, causing significant environmental pollution. Manual gangue sorting is extremely labor-intensive for workers, and over time, it can lead to health problems. How to make judgments based on human experience while also replacing manual handling with machinery is a question worth studying. Summary of the Invention

[0003] To address the aforementioned problems, embodiments of the present invention propose a coal gangue sorting robot based on human-machine collaboration.

[0004] The present invention relates to a human-machine collaborative coal gangue sorting robot, comprising: a robotic arm disposed on one side of a coal gangue conveyor belt, wherein each joint of the robotic arm is equipped with a servo motor and a reducer; a gripper disposed at the free end of the robotic arm, wherein a servo motor is disposed on the gripper and the gripper is vertically positioned above the coal gangue conveyor belt; a skeleton controller mounted on a worker's workstation, wherein each joint of the skeleton controller is equipped with a rotary encoder, the rotary encoder being connected to the servo motor on the robotic arm via pulse signals; a grip disposed at the free end of the skeleton controller, wherein a displacement sensor is disposed in the gripper, the displacement sensor being connected to the servo motor on the gripper via pulse signals; and a camera located above the coal gangue conveyor belt, wherein the camera captures image information on the coal gangue conveyor belt and transmits it to the worker's workstation.

[0005] Optionally, the robotic arm includes a first base, a large arm, and a first waist joint. A boss is provided on the first base, a first servo motor is provided between the boss and the first waist joint, and a second servo motor is provided between the first waist joint and the first large arm.

[0006] Optionally, the robotic arm further includes a first upper arm link and a first triangular link, wherein the first upper arm link, together with the first waist joint, the first upper arm, and the first triangular link, constitute a four-bar linkage.

[0007] Optionally, the robotic arm further includes a first forearm link, a first forearm, and a first wrist joint. The first forearm, the first forearm link, the first triangular link, and the first wrist joint constitute a four-bar linkage. A third servo motor is provided between the first upper arm and the first forearm, and a gripper is provided at the free end of the first wrist joint.

[0008] Optionally, the first wrist joint is equipped with a fourth servo motor to drive the gripper to move up and down.

[0009] Optionally, a fifth servo motor is provided on one side of the gripper and connected to the drive screw through a bevel gear transmission mechanism. The drive screw is connected to the drive nut, and the drive nut drives the support link and the gripper to move through the drive link.

[0010] Optionally, the skeleton controller includes a second base, a second lumbar joint, a second upper arm, a second upper arm connecting rod, and a second triangular connecting rod. The second lumbar joint is provided on the second base, and a fixing member is provided at the front end of the second lumbar joint. The fixing member, the second upper arm, the second upper arm connecting rod, and the second triangular connecting rod form a four-bar linkage mechanism.

[0011] Optionally, the skeleton controller further includes a second forearm, a second forearm link, and a second wrist joint. The rear end of the second forearm is located inside the second triangular link, and the free end of the second wrist joint is connected to the handle. The second forearm, the second forearm link, the second wrist joint, and the second triangular link constitute a four-bar linkage.

[0012] Optionally, the rear end of the second waist joint is rotatably connected to the second base, a first rotary encoder is provided at the connection between the second waist joint and the second base, a second rotary encoder is provided at the connection between the second waist joint and the second upper arm, a third rotary encoder is provided at the connection between the second forearm and the second upper arm, and a fourth rotary encoder is provided inside the second wrist joint.

[0013] Optionally, the grip includes a housing, which is connected to the second wrist joint via a connecting shaft. A trigger is provided inside the housing and is connected to the inner wall of the housing via a spring. Below the trigger is a slope that cooperates with a slider, which is connected to a displacement sensor.

[0014] The beneficial effects of this invention are that by allowing workers to operate the skeleton controller, they can direct the robotic arm at their workstation to pick and transport coal and coal gangue on-site; this can solve the problem that the accuracy of machine vision sorting is not as good as human experience judgment, and can also improve sorting efficiency and reduce the labor intensity of miners. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the robotic arm of the present invention.

[0016] Figure 2 This is a schematic diagram of the skeleton frame controller of the present invention.

[0017] Figure 3 This is a schematic diagram of the clamp of the present invention.

[0018] Figure 4 This is a schematic diagram of the grip structure of the present invention.

[0019] Figure label:

[0020] Robotic arm 1; first base 101; first waist joint 102; first upper arm 103; first upper arm link 104; first triangular link 105; first forearm link 106; first forearm 107; first wrist joint 108;

[0021] Skeleton frame controller 2; second base 201; second upper arm 202; second upper arm link 203; second forearm link 204; second wrist joint 205; second waist joint 206; second forearm 207; fixing component 208; second triangular link 209;

[0022] Clamp 3; gripper 301; support link 302; drive link 303; base 304; drive nut 305; drive screw 306;

[0023] Grip 4; Housing 401; Linear displacement sensor 402; Slider 403; Spring 404; Trigger 405; Connecting shaft 406. Detailed Implementation

[0024] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0025] like Figures 1-4 As shown, the human-machine collaborative coal gangue sorting robot of the present invention includes: a robotic arm 1, a gripper 3, a skeleton controller 2, a handle 4, and a camera. The robotic arm 1 is positioned on one side of the coal gangue conveyor belt, and each joint of the robotic arm 1 is equipped with a servo motor and a reducer. The gripper 3 is located at the free end of the robotic arm 1, and is equipped with a servo motor. The gripper 3 is vertically positioned above the coal gangue conveyor belt. The gripper 3 is used to sort and grip the coal gangue on the conveyor belt, and the servo motor on the gripper 3 is used to control the opening and closing of the gripper 3.

[0026] The skeleton controller 2 is installed at the worker's workstation. Each joint of the skeleton controller 2 is equipped with a rotary encoder, which is connected to the servo motors on the robotic arm 1 via pulse signals. That is, the movements of each joint on the skeleton controller 2 can transmit pulse signals to the servo motors on the robotic arm 1 via the rotary encoders. The servo motors convert the received signals into angular displacement outputs on their output shafts, thereby controlling the corresponding joints to rotate by the corresponding angle. In other words, the rotary encoder outputs pulse signals that can be used to directly control the rotation angle of the servo motors, ensuring that the rotation angle of the joints of the robotic arm 1 is consistent with that of the skeleton controller 2.

[0027] The grip 4 is located at the free end of the skeleton controller 2. The grip 4 is equipped with a displacement sensor, which is connected to the servo motor on the gripper 3 via a pulse signal. That is, the movement displacement of the grip 4 is transmitted to the servo motor on the gripper 3 through the displacement sensor. The servo motor converts the received signal into an angular displacement output on the output shaft, thereby controlling the opening of the gripper to grab the coal gangue.

[0028] The camera is located above the coal gangue conveyor belt. The camera captures images of the coal gangue conveyor belt and transmits them to the worker's workstation. The worker can then use the captured images to identify coal and coal gangue based on experience. By holding the handle 4, the worker can operate the skeleton controller 2, which in turn transmits the joint movement angles on the skeleton controller 2 to the robotic arm 1. This controls the gripper 3 at the end of the robotic arm 1 to grab the coal gangue and transport it to the target location.

[0029] Compared to large coal gangue sorting equipment, robotic arm 1 has a stronger cost advantage, occupies less space, and has a more flexible installation and layout method. With the appropriate gripper 3, robotic arm 1 can achieve a wider range of coal gangue sorting particle sizes.

[0030] The skeleton controller 2 is simply scaled-down from the robotic arm 1, allowing workers to see exactly what they're doing when moving the robotic arm 1 – the movement of the skeleton controller 2 is directly mirrored by the movement of the robotic arm 1. Furthermore, the integrated joint damping on the skeleton controller 2 effectively addresses the ground vibration issue present in most motion-sensing devices, preventing the end effector of the skeleton controller 2 from vibrating due to hand levitation. The rotary encoder on the skeleton controller 2 directly outputs the pulses needed to drive the AC servo motor. This direct connection from the skeleton to the AC servo driver eliminates the intermediate computer processing step, significantly saving overall equipment resources and improving stability and reliability.

[0031] like Figures 1-4As shown, the human-machine collaborative coal gangue sorting robot of the present invention includes: a robotic arm 1, a gripper 3, a skeleton controller 2, a handle 4, and a camera. The robotic arm 1 includes a first base 101, a first upper arm 103, a first waist joint 102, a first upper arm connecting rod 104, a first triangular connecting rod 105, a first forearm connecting rod 106, a first forearm 107, and a first wrist joint 108. The first base 101 is fixed to a base next to the coal gangue conveyor belt and connected by four anchor bolts. The first base 101 is a hollow hemisphere with mounting frames for mounting plates on the right and rear sides. A boss is provided on the hemisphere, with a hole drilled in the center of the boss to facilitate the connection of encoder signals and the power line of the AC servo motor, while preventing the cable from tangling when the robotic arm 1 rotates.

[0032] A first servo motor and an RV-200C reducer are provided between the boss and the lower part of the first waist joint 102. The first servo motor can drive the first waist joint 102 to rotate relative to the boss.

[0033] A second servo motor and an RV-320E reducer are provided between the upper front end of the first waist joint 102 and the thicker end of the first upper arm 103. The second servo motor can drive the first upper arm 103 to rotate relative to the first waist joint 102.

[0034] The upper rear end of the first waist joint 102 is equipped with a rotating shaft of the first upper arm connecting rod 104, so that the first upper arm connecting rod 104 can rotate relative to the first waist joint 102.

[0035] The thinner end of the first upper arm 103 is rotatably connected to the first lower arm 107 via a third servo motor and an RV-220E reducer, allowing the first lower arm 107 to rotate relative to the top of the first upper arm 103.

[0036] The mounting shaft of the first triangular connecting rod 105 is provided on the other side of the thinner end of the first large arm 103, forming the rotation center of the first triangular connecting rod.

[0037] The first upper arm link 104, together with the first waist joint 102, the first upper arm 103, and the first triangular link 105, constitute a four-bar linkage, so that during the rotation of the first upper arm 103, the first triangular link 105 always remains without horizontal rotation.

[0038] The thicker end of the first forearm 107 is rotatably connected to the thinner end of the first upper arm 107. The thinner end of the first forearm 107 is connected to the first wrist joint 108, which can rotate around the central axis of the thinner end of the first forearm 107.

[0039] The first forearm 107, the first forearm link 106, the first triangular link 105, and the first wrist joint 108 constitute a four-bar linkage. The first triangular link 105 is restricted by the first waist joint 102 and will not rotate horizontally, and the first wrist joint 108 is also restricted by the first triangular link 105 and will not rotate horizontally. Therefore, the gripper 3 located at the free end of the first wrist joint 108 is always perpendicular to the coal gangue sorting conveyor belt.

[0040] The first wrist joint 108 drives the base 304 of the gripper 3 to move up and down via the fourth servo motor and RV-6E reducer.

[0041] A fifth servo motor is installed on one side of the clamp 3. The output shaft of the fifth servo motor is connected to the drive screw 306 through a bevel gear transmission mechanism, which changes the motion direction of the fifth servo motor by 90°, saving vertical installation space.

[0042] The drive screw 306 is connected to the drive nut 305, which drives the support link 302 and the gripper 301 to move via the drive link 303. The base 304, drive link 303, support link 302 and gripper 301 constitute a four-bar linkage gripper. All links are widened and thickened to enhance the gripper's strength and increase its effective load. The gripper 301 at the end of the gripper 3 has inward barbs to prevent slippage when gripping coal gangue. When a force sensor is installed, the gripper can provide feedback to the worker on the current gripping force, facilitating flexible operation.

[0043] The skeleton controller 2 includes a second base 201, a second lumbar joint 206, a second upper arm 202, a second upper arm connecting rod 203, a second triangular connecting rod 209, a second forearm 207, a second forearm connecting rod 204, and a second wrist joint 205. The second base 201 is fixed to the workstation. The second lumbar joint 206 is mounted on the second base 201. A fixing member 208 is mounted at the front end of the second lumbar joint 206. The fixing member 208, the second upper arm 202, the second upper arm connecting rod 203, and the second triangular connecting rod 209 form a four-bar linkage mechanism. The fixing member 208 is a sheet metal part.

[0044] The rear end of the second waist joint 206 is rotatably connected to the second base 201. A first rotary encoder is provided at the connection between the second waist joint 206 and the second base 201, so that the rotation angle of the second waist joint 206 relative to the second base 201 can be fed back to the first rotary encoder. The first rotary encoder corresponds to the first servo motor.

[0045] A second rotary encoder is provided at the connection between the fixing member 208 of the second waist joint 206 and the second upper arm 202. That is, the fixing member 208 of the second waist joint 206 and the lower end of the second upper arm 202 are connected to the second rotary encoder through a rotating shaft. The second rotary encoder corresponds to the second servo motor.

[0046] A third rotary encoder is installed at the connection between the second forearm 207 and the second upper arm 202. The second forearm 207 and the second upper arm 202 are connected by gears; that is, a gear is designed at the rear end of the second forearm 207, which meshes with a gear at the upper end of the second upper arm 202. The upper end of the second upper arm 202 transmits the rotation angle of the second forearm 207 to the third rotary encoder through gear transmission. The third rotary encoder corresponds to a third servo motor.

[0047] The second upper arm 202 is supported in the middle by a front cover plate to ensure rigidity. The rear end of the second forearm 207 is bent to avoid the gears in the second upper arm 202 and together with the second forearm connecting rod 204, it forms a mechanical limit. The front end of the second forearm 207 is connected to the second wrist joint 205 and becomes the rotation center of the second wrist joint 205.

[0048] The rear end of the second forearm 207 is located inside the second triangular link 209. The second forearm 207, the second forearm link 204, the second wrist joint 205, and the second triangular link 209 constitute a four-bar linkage. The outer surfaces of the second upper arm link 203 and the second forearm link 204 are wide, covering the outer surfaces of the second forearm 207 and the second upper arm 202 of the skeleton controller 2 to a certain extent, thus protecting both the worker and the machine.

[0049] The free end of the second wrist joint 205 is connected to the grip 4, and a fourth rotary encoder is installed inside the second wrist joint 205. The fourth rotary encoder corresponds to the fourth servo motor.

[0050] The grip 4 includes a housing 401, which is connected to the second wrist joint 05 via a connecting shaft 406. Inside the housing 401 is a trigger 405 that performs linear motion. The trigger 405 is connected to the inner wall of the housing 401 via a spring 404, meaning the trigger 405 rebounds via the spring 404. Below the trigger 405 is a slope, which engages with a slider 403. The slider 403 is connected to a displacement sensor 402. When the trigger 405 moves backward, the slope causes the internal slider 403 to move downward along a groove, pushing the displacement sensor 402 into linear motion. The position signal output by the displacement sensor 402 determines the rotation angle of the drive screw 306 in the gripper 3, thereby controlling the opening degree of the gripper 301 in the gripper 3. The displacement sensor 402 corresponds to the fifth servo motor.

[0051] like Figures 1-4 As shown, the specific working steps of the coal gangue sorting robot based on human-machine collaboration of the present invention are as follows:

[0052] (1) Preliminary preparations and equipment installation

[0053] The coal gangue conveyor belt transports the coal gangue to the sorting area. An industrial camera is placed directly above the sorting area to transmit real-time images of the coal gangue on the conveyor belt to the placement station of the skeleton controller 2.

[0054] Robotic arm 1 is installed next to the conveyor belt. The installation height and distance are adjusted to ensure that robotic arm 1 has sufficient room to move and that its range of motion covers the conveyor belt.

[0055] The skeleton controller 2 is installed at the worker's workstation. Adjusting its installation height and distance from the coal gangue image display screen allows the worker to easily operate the skeleton controller.

[0056] Connect the rotation pulse signal line of the skeleton controller 2 to the robotic arm 1, turn on the power to the device, power on the system, and the electrical devices are ready. All devices return to their default initial state, and the system is enabled.

[0057] (2) The skeleton controller directs the movement of the robotic arm.

[0058] The worker observes the coal gangue image transmitted by the industrial camera, holds the handle 4 of the skeleton controller 2, and drags the skeleton controller 2 with the handle 4. The rotary encoder on the skeleton controller 2 sends the rotation angle of each joint to the corresponding servo motor on the robotic arm 1 in the form of pulses. After receiving the pulse signal, the robotic arm 1 controls the motor to rotate, so that the movement posture of the robotic arm 1 is synchronized with the skeleton controller 2. When the worker directs the robotic arm 1 to move above the coal gangue to be sorted, the worker controls the displacement stroke of the trigger 405. The displacement sensor outputs an analog signal to control the rotation angle of the servo motor on the gripper 3. The bevel gear and screw-nut mechanism on the gripper 3 converts the rotational motion of the servo motor into the linear motion of the driving nut 305, thereby controlling the opening of the gripper 3's jaws 301. After adjusting the gripping posture, the worker controls the jaws 301 to pick up the coal gangue and continues to operate the robotic arm 1 to transport the coal gangue to the target position.

[0059] (3) Initial and ending default states

[0060] Robotic arm 1 and skeleton controller 2 need to move in synchronized motion at all times. When the system starts or stops moving, it needs to return to its default state. In the default state, robotic arm 1 and skeleton controller 2 check the current default angle and calibrate their synchronization. After returning to the default state, the system is either enabled or disabled.

[0061] All servo motors used in this application are AC servo motors.

[0062] The reducer model can be RV-200C, RV-320E, RV-220E or RV-6E.

[0063] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0064] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0065] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0066] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0067] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A coal gangue sorting robot based on human-machine collaboration, characterized in that, include: The robotic arm (1) is set on one side of the coal gangue conveyor belt, and each joint of the robotic arm (1) is equipped with a servo motor and a reducer. The robotic arm (1) includes a first base (101), a first upper arm (103) and a first waist joint (102). A boss is provided on the first base (101), a first servo motor is provided between the boss and the first waist joint (102), and a second servo motor is provided between the first waist joint (102) and the first upper arm (103). The robotic arm (1) further includes a first upper arm link (104) and a first triangular link (105). The first upper arm link (104), together with the first waist joint (102), the first upper arm (103), and the first triangular link (105), constitute a four-bar linkage. The robotic arm (1) further includes a first forearm link (106), a first forearm (107) and a first wrist joint (108). The first forearm (107), the first forearm link (106), the first triangular link (105) and the first wrist joint (108) constitute a four-bar linkage. The first upper arm (103) and the first forearm (107) are rotatably connected by a third servo motor. A gripper (3) is provided at the free end of the first wrist joint (108). The gripper (3) is located at the free end of the robotic arm (1), and a servo motor is provided on the gripper (3). The gripper (3) is located vertically above the coal gangue conveyor belt. Skeleton frame controller (2), the skeleton frame controller (2) is installed on the worker's workstation, and each joint of the skeleton frame controller (2) is equipped with a rotary encoder, the rotary encoder is connected to the servo motor on the robotic arm (1) through a pulse signal; The grip (4) is located at the free end of the skeleton controller (2). A displacement sensor is installed in the grip (4). The displacement sensor is connected to the servo motor on the clamp (3) via a pulse signal. The grip (4) includes a housing (401), which is connected to the second wrist joint (205) via a connecting shaft (406). A trigger (405) is provided inside the housing (401), which is connected to the inner wall of the housing (401) via a spring (404). The trigger (405) has a slope below it, which cooperates with a slider (403). The slider (403) is connected to a displacement sensor (402). The camera is located above the coal gangue conveyor belt. The camera captures images of the coal gangue conveyor belt and transmits them to the workers' workstations.

2. The coal gangue sorting robot based on human-machine collaboration according to claim 1, characterized in that, The first wrist joint (108) drives the base (304) of the gripper to move up and down via the fourth servo motor.

3. The coal gangue sorting robot based on human-machine collaboration according to claim 2, characterized in that, A fifth servo motor is provided on one side of the clamp (3) and is connected to the drive screw (306) through a bevel gear transmission mechanism. The drive screw (306) is connected to the drive nut (305). The drive nut (305) drives the support link (302) and the gripper (301) to move through the drive link (303).

4. The coal gangue sorting robot based on human-machine collaboration according to claim 1, characterized in that, The skeleton controller (2) includes a second base (201), a second lumbar joint (206), a second upper arm (202), a second upper arm link (203), and a second triangular link (209). The second lumbar joint (206) is provided on the second base (201). A fixing member (208) is provided at the front end of the second lumbar joint (206). The fixing member (208), the second upper arm (202), the second upper arm link (203), and the second triangular link (209) constitute a four-bar linkage mechanism.

5. The coal gangue sorting robot based on human-machine collaboration according to claim 4, characterized in that, The skeleton controller (2) further includes a second forearm (207), a second forearm link (204), and a second wrist joint (205). The rear end of the second forearm (207) is located inside the second triangular link (209), and the free end of the second wrist joint (205) is connected to the handle (4). The second forearm (207), the second forearm link (204), the second wrist joint (205), and the second triangular link (209) constitute a four-bar linkage.

6. The coal gangue sorting robot based on human-machine collaboration according to claim 5, characterized in that, The rear end of the second waist joint (206) is rotatably connected to the second base (201). A first rotary encoder is provided at the connection between the second waist joint (206) and the second base (201). A second rotary encoder is provided at the connection between the fixing member (208) of the second waist joint (206) and the second upper arm (202). A third rotary encoder is provided at the connection between the second forearm (207) and the second upper arm (202). A fourth rotary encoder is provided inside the second wrist joint (205).

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