An automatic induction clamping mechanical arm and a control method thereof

Abstract

The application discloses an automatic induction clamping mechanical arm and a control method thereof, and belongs to the technical field of mechanical arms. The automatic induction clamping mechanical arm comprises a rotating base, a first rotating arm is installed on the rotating base, a second rotating arm is installed at the tail end of the first rotating arm, a rotating motor is installed at the tail end of the second rotating arm, joints are arranged between the rotating base and the first rotating arm, the first rotating arm and the second rotating arm, and the second rotating arm and the rotating motor, the rotating motor is connected with a mechanical claw, the clamping claw of the mechanical claw is a rubber antiskid soft finger, and the rotating base, the first rotating arm, the second rotating arm, the rotating motor and the mechanical claw are connected with a control system. The automatic induction clamping mechanical arm and the control method thereof are adopted, high-precision and accurate positioning of the mechanical arm is realized, the cup opening is accurately overlapped with each discharge opening, and material spilling is avoided; the rubber antiskid soft finger is adopted to realize flexible self-adaptive clamping, and the workpiece adaptability and safety are higher; full-dimension state monitoring is adopted, and the equipment operation stability and service life are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of robotic arm technology, and in particular to an automatic sensing and gripping robotic arm and its control method. Background Technology

[0002] Existing automated beverage preparation robotic arms rely solely on encoders for fixed-point teaching and positioning, lacking multi-dimensional sensing and detection capabilities. This makes them unable to identify dynamic errors such as joint clearances, equipment temperature rise deformation, and arm sway, resulting in significant positioning deviations over long-term operation. The end-effector gripping structure is mostly a rigid two-point gripper without pressure detection or posture correction functions, making it prone to cup eccentricity, slippage, and tilting, leading to cup rim misalignment. Furthermore, the lack of gripping self-checking, temperature compensation, and error iteration functions prevents them from adapting to changes in operating conditions and equipment aging errors. This results in poor equipment stability and consistency, failing to meet the high-precision, unmanned, continuous operation requirements of automated beverage preparation. Summary of the Invention

[0003] The purpose of this invention is to provide an automatic sensing and clamping robotic arm and its control method, which achieves high-precision positioning of the robotic arm, ensures that the cup opening and each discharge port are accurately aligned, and avoids material spillage; adopts rubber anti-slip soft fingers to achieve flexible adaptive clamping, which improves workpiece adaptability and safety; and provides all-dimensional status monitoring, which greatly improves the stability and lifespan of the equipment.

[0004] To achieve the above objectives, the present invention provides an automatic sensing and gripping robotic arm, comprising a rotating base, a first rotating arm mounted on the rotating base, a second rotating arm mounted at the end of the first rotating arm, and a rotary motor mounted at the end of the second rotating arm. The rotating base and the first rotating arm, the first rotating arm and the second rotating arm, and the second rotating arm and the rotary motor are all connected via joints. The rotary motor is connected to a robotic gripper, the gripper having rubber anti-slip soft fingers. The rotating base, the first rotating arm, the second rotating arm, the rotary motor, and the robotic gripper are connected to a control system. The control system includes a data acquisition module, a data processing module, and a data transmission module. The data acquisition module is used to acquire operational data; the data processing module is used to process the acquired data and generate control commands; and the data transmission module is used to transmit the control commands.

[0005] Preferably, the data acquisition module includes a rotary encoder, a temperature sensor, a tilt sensor, a laser rangefinder, a vision camera, a photoelectric sensor, a distributed matrix pressure sensor, and a load cell. The rotary encoder and temperature sensor are mounted on the joint, the tilt sensor, laser rangefinder, vision camera, and photoelectric sensor are mounted on the mechanical gripper, and the distributed matrix pressure sensor and load cell are mounted on the inside of the gripper.

[0006] This invention provides a control method for an automatically sensing and gripping robotic arm, applied to the aforementioned automatically sensing and gripping robotic arm, specifically including the following steps: S1. System power-on self-test and zero-position calibration; S2, cup adaptive clamping closed-loop control; S3. Forward solution calculation of multi-joint rotational coordinates; S4, Attitude and Distance Closed-Loop Correction; S5. Visually precise alignment deviation compensation; S6. Dual positioning verification and material unloading execution; S7. Real-time compensation and reset iteration for running errors.

[0007] Preferably, in S1, a joint zero-position deviation correction formula is used to eliminate zero-point drift of the device upon power-on and initial deviation of the sensor, and to establish a global coordinate system reference for the robotic arm. The joint zero-position deviation correction formula is as follows: ; in, For the first Initial zero-position deviation of each joint upon power-up For the first The rotary encoder of each joint initially reads the angle upon power-up. For the first The mechanical standard zero angle of each joint. Number the joints.

[0008] Preferably, in S2, the clamping force and the weight of the cup are collected by a distributed matrix pressure sensing pad and a weighing sensor for dual determination to achieve adaptive clamping. The clamping force balance determination formula is as follows: ; in, For the uneven distribution of clamping force, The maximum single-point clamping pressure collected by the matrix pressure sensing pad. The minimum single-point clamping pressure collected by the matrix pressure sensing pad. This represents the average pressure at all data collection points of the matrix pressure sensing pad. The formula for determining the weight of a cup is as follows: ; in, The actual weight of the cup. To hold the cup in place, the real-time reading of the weighing sensor is required. This is the zero-point reference weight of the weighing sensor when there is no cup.

[0009] Preferably, in S3, based on the structural parameters of the pure rotating arm and the joint angles, the global XY coordinates of the cup rim center are calculated in real time to determine the real-time spatial position of the cup. The formula for calculating the local coordinates of the cup rim center relative to the rotation center of the rotating base is as follows: ; in, The effective length of the first rotating arm. The real-time rotation angle of the first rotating arm. The effective arm length of the second rotating arm. This refers to the real-time rotation angle of the second rotating arm. The global coordinate transformation formula for the rotating base is shown below: ; in, The X-coordinate of the global coordinate system at the center of the cup rim. The Y-coordinate of the global coordinate system at the center of the cup rim. The rotating base rotates at a constant angle in real time.

[0010] Preferably, in step S4, the tilt sensor corrects the horizontal attitude of the cup, and the laser rangefinder calibrates the vertical drop of the workstation. The formula for correcting the horizontal attitude deviation of the cup is as follows: ; in, For the attitude compensation angle of the rotary motor. The horizontal tilt angle of the tilt sensor's X-axis. The horizontal tilt angle of the tilt sensor's Y-axis; The formula for the vertical drop deviation of the workstation is as follows: ; in, This represents the deviation between the actual drop and the standard drop. To achieve the optimal vertical drop for material unloading at the workstation. To enable laser rangefinders to detect elevation differences in real time.

[0011] Preferably, in S5, the visual camera identifies the center offset between the cup opening and the outlet, and fine-tunes the joint angle to achieve precise centering. The visual plane offset compensation formula is as follows: ; in, This is the center offset in the X-axis direction. This represents the center offset along the Y-axis.

[0012] Preferably, S6 uses both coordinate threshold verification and photoelectric through-beam switch verification to simultaneously ensure that the cup is fully in place without deviation. The formula for the cup placement determination threshold is as follows: ; in, This represents the maximum allowable positioning error for the workstation.

[0013] Preferably, the compensation amount for joint angle drift caused by temperature in S7 ensures stable long-term operating accuracy of the equipment. The joint angle drift compensation formula is as follows: ; in, This is the joint temperature angle drift coefficient. To monitor joint temperature in real time. This is the standard operating reference temperature for the equipment.

[0014] Therefore, the present invention adopts the above-mentioned automatic sensing and clamping robotic arm and its control method to achieve high-precision positioning of the robotic arm, ensuring that the cup mouth and each discharge port are accurately aligned to avoid material spillage; the use of rubber anti-slip soft fingers to achieve flexible adaptive clamping, resulting in higher workpiece adaptability and safety; and full-dimensional status monitoring, which greatly improves the stability and lifespan of the equipment.

[0015] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of an automatic sensing and gripping robotic arm according to the present invention; Figure 2 This is a schematic diagram of the mechanical gripper in an automatic sensing and clamping robotic arm according to the present invention; Figure 3 The flowchart of the control method for an automatic sensing and gripping robotic arm of the present invention.

[0017] Figure Labels 1. Rotating base; 2. First rotating arm; 3. Second rotating arm; 4. Rotary motor; 5. Mechanical gripper; 6. Clamping jaw. Detailed Implementation

[0018] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0020] Example 1 like Figures 1 to 2 As shown, this invention provides an automatic sensing and gripping robotic arm, including a rotating base 1, a first rotating arm 2 mounted on the rotating base 1, a second rotating arm 3 mounted at the end of the first rotating arm 2, and a rotary motor 4 mounted at the end of the second rotating arm 3. The rotating base 1 is connected to the first rotating arm 2, the first rotating arm 2 to the second rotating arm 3, and the second rotating arm 3 to the rotary motor 4 via joints. The rotary motor 4 is connected to a robotic gripper 5, whose grippers 6 are made of rubber anti-slip soft fingers. The rotating base 1 serves as the overall load-bearing reference and horizontal rotation base, bearing the entire load of the first rotating arm 2, the second rotating arm 3, and the end robotic gripper 5. Through its own rotation, it achieves overall horizontal circumferential adjustment of the robotic arm, enabling wide-range switching between three workstations, and is the basic moving component for equipment positioning. The first rotating arm 2 and the second rotating arm 3 form a two-bar linkage mechanism. Through the coordinated rotation of two-stage joints, it achieves precise adjustment of the planar position of the end robotic gripper 5, compensating for the positioning shortcomings of the equipment lacking a telescopic structure. Together with the rotating base 1, it completes the XY coordinate positioning of the cup opening plane, covering the working areas of each discharge port. The joints provide rotational freedom for each moving component and are equipped with rotary encoders and temperature sensors to collect joint motion and status data. A rotary motor 4 independently drives the mechanical gripper 5 to adjust its rotation, correcting the cup's tilt angle and aligning the rim to suit different workstation alignment requirements, achieving adaptive calibration of the cup's level. As the end effector, the mechanical gripper features a rubber anti-slip soft-fin structure, suitable for fragile and slippery cups such as glass. The soft grip prevents cup deformation from compression and also provides a mounting platform for the distributed matrix pressure sensing pad and load cells.

[0021] The rotating base 1, the first rotating arm 2, the second rotating arm 3, the rotating motor 4, and the mechanical claw 5 are connected to the control system. The control system includes a data acquisition module, a data processing module, and a data transmission module. The data acquisition module is used to acquire operating data. The data processing module is used to process the acquired data and generate control commands. The data transmission module is used to transmit the control commands.

[0022] The data acquisition module includes a rotary encoder, temperature sensor, tilt sensor, laser rangefinder, vision camera, photoelectric sensor, distributed matrix pressure sensor, and load cell. The rotary encoder and temperature sensor are mounted on the joints, while the tilt sensor, laser rangefinder, vision camera, and photoelectric sensor are mounted on the mechanical gripper 5. The distributed matrix pressure sensor and load cell are mounted inside the gripper 6. The rotary encoder collects real-time rotation angles of the rotating base, first rotating arm, second rotating arm, and rotary motor, providing raw data for coordinate calculation, zero-position calibration, and angle compensation. The temperature sensor collects real-time operating temperatures of the joints and motor, monitoring the equipment's temperature rise and providing data for temperature drift error compensation. The tilt sensor detects the horizontal tilt angles of the cup body along the X and Y axes in real-time to determine the cup's posture. The laser rangefinder detects the vertical drop height between the cup's opening and each discharge port in real-time. The vision camera captures real-time images of the discharge port and cup opening, identifying the center offset between them. The photoelectric sensor is used for hardware positioning detection at the workstation, outputting a switch signal indicating that the workstation is in position. A distributed matrix pressure sensing pad collects pressure data at multiple points in the clamping area to detect the distribution of clamping pressure. A weighing sensor detects changes in the weight of the clamped cup in real time.

[0023] like Figure 3 As shown, the present invention provides a control method for an automatically sensing and gripping robotic arm, applied to the aforementioned automatically sensing and gripping robotic arm, specifically including the following steps: S1. System power-on self-test and zero-position calibration; The joint zero-position deviation correction formula is used to eliminate the zero-point drift of the device upon power-on and the initial deviation of the sensors, and to establish a global coordinate system reference for the robotic arm. The joint zero-position deviation correction formula is as follows: ; in, For the first Initial zero-position deviation of each joint upon power-up For the first The rotary encoder of each joint initially reads the angle upon power-up. For the first The mechanical standard zero angle of each joint. Number the joints.

[0024] S2, cup adaptive clamping closed-loop control; The clamping force and the cup's own weight are collected by a distributed matrix pressure sensing pad and a weighing sensor for dual judgment to achieve adaptive clamping, ensuring that the cup does not slip, deviate, or deform, and fixing the center reference of the cup mouth. The clamping force balance judgment formula is as follows: ; in, For the uneven distribution of clamping force, The maximum single-point clamping pressure collected by the matrix pressure sensing pad. The minimum single-point clamping pressure collected by the matrix pressure sensing pad. This represents the average pressure at all data collection points of the matrix pressure sensing pad. The formula for determining the weight of a cup is as follows: ; in, The actual weight of the cup. To hold the cup in place, the real-time reading of the weighing sensor is required. This is the zero-point reference weight of the weighing sensor when there is no cup.

[0025] S3. Forward solution calculation of multi-joint rotational coordinates; Based on the structural parameters and joint angles of the pure rotating arm, the global XY coordinates of the cup rim center are calculated in real time to determine the real-time spatial position of the cup. The formula for calculating the local coordinates of the cup rim center relative to the rotation center of the base is shown below: ; in, The effective length of the first rotating arm. The real-time rotation angle of the first rotating arm. The effective arm length of the second rotating arm. This refers to the real-time rotation angle of the second rotating arm. The global coordinate transformation formula for the rotating base is shown below: ; in, The X-coordinate of the global coordinate system at the center of the cup rim. The Y-coordinate of the global coordinate system at the center of the cup rim. The rotating base rotates at a constant angle in real time.

[0026] S4, Attitude and Distance Closed-Loop Correction; The horizontal orientation of the cup is corrected by an angle sensor, and the vertical drop of the workstation is calibrated by a laser rangefinder to prevent material spillage caused by deviations in the cup's tilt height. The formula for correcting the horizontal orientation deviation of the cup is as follows: ; in, For the attitude compensation angle of the rotary motor. The horizontal tilt angle of the tilt sensor's X-axis. The horizontal tilt angle of the tilt sensor's Y-axis; The formula for the vertical drop deviation of the workstation is as follows: ; in, This represents the deviation between the actual drop and the standard drop. To achieve the optimal vertical drop for material unloading at the workstation. To enable laser rangefinders to detect elevation differences in real time.

[0027] S5. Visually precise alignment deviation compensation; By identifying the center misalignment between the cup opening and the outlet using a visual camera, the joint angle is finely adjusted to achieve precise alignment. The visual plane misalignment compensation formula is shown below: ; in, This is the center offset in the X-axis direction. This represents the center offset along the Y-axis.

[0028] S6. Dual positioning verification and material unloading execution; The system employs a dual verification method, combining coordinate threshold verification and photoelectric through-beam switch verification, to ensure the cup is fully positioned without deviation and to prevent misaligned feeding. The cup positioning threshold formula is shown below: ; in, This represents the maximum allowable positioning error for the workstation.

[0029] S7. Real-time compensation and reset iteration for running errors; The compensation amount for joint angle drift caused by temperature ensures stable long-term equipment operation accuracy and avoids deviation caused by cumulative errors. The joint angle drift compensation formula is shown below: ; in, This is the joint temperature angle drift coefficient. To monitor joint temperature in real time. This is the standard operating reference temperature for the equipment.

[0030] Therefore, the present invention adopts the above-mentioned automatic sensing and clamping robotic arm and its control method to achieve high-precision positioning of the robotic arm, ensuring that the cup mouth and each discharge port are accurately aligned to avoid material spillage; the use of rubber anti-slip soft fingers to achieve flexible adaptive clamping, resulting in higher workpiece adaptability and safety; and full-dimensional status monitoring, which greatly improves the stability and lifespan of the equipment.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An automatic sensing and gripping robotic arm, characterized in that: The system includes a rotating base, on which a first rotating arm is mounted. A second rotating arm is mounted at the end of the first rotating arm, and a rotary motor is mounted at the end of the second rotating arm. The rotating base, the first rotating arm, the second rotating arm, and the rotary motor are all connected via joints. The rotary motor is connected to a mechanical gripper, whose grippers are made of rubber anti-slip soft fingers. The rotating base, the first rotating arm, the second rotating arm, the rotary motor, and the mechanical gripper are connected to a control system. The control system includes a data acquisition module, a data processing module, and a data transmission module. The data acquisition module is used to acquire operational data; the data processing module is used to process the acquired data and generate control commands; and the data transmission module is used to transmit the control commands.

2. The automatic sensing and gripping robotic arm and its control method according to claim 1, characterized in that: The data acquisition module includes a rotary encoder, a temperature sensor, an inclination sensor, a laser rangefinder, a vision camera, a photoelectric through-beam switch, a distributed matrix pressure sensor, and a load cell. The rotary encoder and temperature sensor are mounted on the joint, while the inclination sensor, laser rangefinder, vision camera, and photoelectric through-beam switch are mounted on the mechanical gripper. The distributed matrix pressure sensor pad and load cell are mounted on the inside of the gripper.

3. A control method for an automatically sensing and gripping robotic arm, applied to the automatically sensing and gripping robotic arm described in any one of claims 1-2, characterized in that: Specifically, the following steps are included: S1. System power-on self-test and zero-position calibration; S2, Cup adaptive clamping closed-loop control; S3. Forward Coordinate Calculation for Multi-Joint Rotation S4, Attitude and Distance Closed-Loop Correction; S5. Visually precise alignment deviation compensation; S6. Dual positioning verification and material unloading execution; S7. Real-time compensation and reset iteration for running errors.

4. The control method for an automatic sensing and gripping robotic arm according to claim 3, characterized in that: In S1, a joint zero-position deviation correction formula is used to eliminate power-on zero-point drift and initial sensor deviation, and to establish a global coordinate system reference for the robotic arm. The joint zero-position deviation correction formula is as follows: ； in, For the first Initial zero-position deviation of each joint upon power-up For the first The rotary encoder of each joint initially reads the angle upon power-up. For the first The mechanical standard zero angle of each joint. Number the joints.

5. The control method for an automatic sensing and gripping robotic arm according to claim 4, characterized in that: In S2, the clamping force and the weight of the cup are collected by a distributed matrix pressure sensing pad and a weighing sensor for dual determination to achieve adaptive clamping. The clamping force balance determination formula is as follows: ； in, For the uneven distribution of clamping force, The maximum single-point clamping pressure collected by the matrix pressure sensing pad. The minimum single-point clamping pressure collected by the matrix pressure sensing pad. This represents the average pressure at all data collection points of the matrix pressure sensing pad. The formula for determining the weight of a cup is as follows: ； in, The actual weight of the cup. To hold the cup in place, the weighing sensor reads the value in real time. This is the zero-point reference weight of the weighing sensor when there is no cup.

6. The control method for an automatic sensing and gripping robotic arm according to claim 5, characterized in that: In S3, relying on the structural parameters and joint angles of the pure rotating arm, the global XY coordinates of the cup rim center are calculated in real time to determine the real-time spatial position of the cup. The formula for calculating the local coordinates of the cup rim center relative to the rotation center of the rotating base is shown below: ； in, The effective length of the first rotating arm. The real-time rotation angle of the first rotating arm. This is the effective arm length of the second rotating arm. This refers to the real-time rotation angle of the second rotating arm. The global coordinate transformation formula for the rotating base is shown below: ； in, The X-coordinate of the global coordinate system at the center of the cup rim. The Y-coordinate of the global coordinate system at the center of the cup rim. The rotating base rotates at a constant angle in real time.

7. The control method for an automatic sensing and gripping robotic arm according to claim 6, characterized in that: In S4, the tilt sensor corrects the horizontal attitude of the cup, and the laser rangefinder calibrates the vertical drop of the workstation. The formula for correcting the horizontal attitude deviation of the cup is as follows: ； in, For the attitude compensation angle of the rotary motor. The horizontal tilt angle of the tilt sensor's X-axis. The horizontal tilt angle of the tilt sensor's Y-axis; The formula for the vertical drop deviation of the workstation is as follows: ； in, This represents the deviation between the actual drop and the standard drop. To achieve the optimal vertical drop for material unloading at the workstation. To enable laser rangefinders to detect elevation differences in real time.

8. The control method for an automatic sensing and gripping robotic arm according to claim 7, characterized in that: In S5, a vision camera identifies the center misalignment between the cup opening and the outlet, and fine-tunes the joint angle to achieve precise alignment. The vision plane offset compensation formula is shown below: ； in, This is the center offset in the X-axis direction. This represents the center offset along the Y-axis.

9. The control method for an automatic sensing and gripping robotic arm according to claim 8, characterized in that: S6 uses both coordinate threshold verification and photoelectric through-beam switch verification to simultaneously ensure that the cup is fully positioned without deviation. The formula for the cup positioning judgment threshold is as follows: ； in, This represents the maximum allowable positioning error for the workstation.

10. The control method for an automatic sensing and gripping robotic arm according to claim 9, characterized in that: S7 compensates for joint angle drift caused by temperature, ensuring stable accuracy during long-term equipment operation. The joint angle drift compensation formula is shown below: ； in, This is the joint temperature angle drift coefficient. To monitor joint temperature in real time. This is the standard operating reference temperature for the equipment.

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