Electromagnetically driven robot

Abstract

The present application relates to a kind of electromagnetic drive's mechanical hand, comprising: base, for disc-shaped structure, several radial slide ways are made on base along circumferential direction interval;Several finger assemblies, bottom end is respectively radially slidably installed in several slide ways;Magnet assembly, fixedly installed in finger assembly, drive finger assembly to bend or stretch through magnet assembly;Several finger assemblies slide together towards, and realize the action of grabbing again by driving towards bending through magnet assembly.This mechanical hand passes through the electromagnetic array embedded in flexible finger shell and is electrified, directly generates electromagnetic force and stimulates finger to occur bending, torsion or telescopic deformation, to realize the enveloping of target object and is grabbed.This design guarantees enough clamping force, utilizes the flexible elasticity of silica gel effectively to avoid extrusion damage to object surface, and gives consideration to grabbing efficiency and intact rate, especially suitable for automatic nondestructive picking operation of berry type easily damaged fruit.

Description

Technical Field

[0001] This invention belongs to the field of robotics technology, and relates to robotic arms, particularly an electromagnetically driven robotic arm. Background Technology

[0002] Traditional industrial robotic arms and pneumatic grippers are typically composed of rigid metal links, rotary joints, servo motors, reducers, gears, and other transmission mechanisms. While these robotic arms have strong load-bearing capacity and high repeatability, they are bulky, have limited degrees of freedom, and are poorly adaptable to irregularly shaped or fragile objects, making it difficult to achieve compliant gripping safely in unstructured environments. In addition, rigid structures pose safety hazards during human-robot collaboration. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide an electromagnetically driven robotic arm with high degree of freedom and high compliance.

[0004] To solve the above problems, the technical solution of the present invention is as follows:

[0005] An electromagnetically driven robotic arm, comprising:

[0006] The base is a disc-shaped structure, with several radially arranged sliding tracks spaced along the circumference of the base.

[0007] Several finger components are radially slidably mounted in several slide tracks at their bottom ends;

[0008] A magnet assembly is fixedly installed inside the finger assembly, and the finger assembly is driven to bend or extend by the magnet assembly;

[0009] Several finger components slide and converge towards each other, and are then driven by a magnetic component to bend towards each other to achieve a grasping action.

[0010] In a further embodiment, a finger shell is also included, which is made of a flexible material. The finger shell includes a plurality of spaced finger segments, the inner sides of which are connected to each other and the outer sides are left with gaps.

[0011] A magnet assembly is fixedly installed inside the finger segment.

[0012] In a further embodiment, magnetic particles are provided inside the finger shell;

[0013] The inner surface of the finger shell has raised textures.

[0014] In a further embodiment, the magnet assembly includes a pair of permanent magnets and a plurality of electromagnets. The pair of permanent magnets are respectively fixedly installed at both ends of the finger assembly, and the plurality of electromagnets are respectively fixedly installed in a plurality of finger segments and located between the pair of permanent magnets.

[0015] Several electromagnets are energized.

[0016] In a further embodiment, the surface of the finger segment is covered with a coating suitable for limiting the electromagnet.

[0017] In a further embodiment, the magnetic fields of adjacent electromagnets are in opposite directions;

[0018] The magnetic poles of a pair of permanent magnets are set in opposite directions.

[0019] In a further embodiment, the finger assembly also includes a mounting block and a reinforcing frame, both of which are rectangular frame structures;

[0020] The base of the finger shell is fixedly installed inside the reinforcing frame, which in turn is fixedly installed inside the mounting block.

[0021] In a further embodiment, a limiting part is formed on the mounting block, and the limiting part is located inside the slide rail;

[0022] The shape of the limiting part corresponds to the slide rail.

[0023] In a further embodiment, a connecting plate is fixedly mounted on the lower end face of the base, suitable for connecting external control equipment.

[0024] In a further embodiment, the connecting disc is provided with a plurality of weight-reducing holes at intervals.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] 1. This robotic arm combines the flexible properties of silicone with the rapid response of electromagnetic drive. Its operation involves energizing an array of electromagnets embedded in the flexible finger shell, directly generating electromagnetic force to excite the fingers to bend, twist, or extend, thereby achieving an envelope gripping of the target object. This design ensures sufficient gripping force while effectively avoiding surface damage due to the flexibility of silicone, balancing gripping efficiency and integrity. It is particularly suitable for automated, non-destructive harvesting of fragile fruits such as berries.

[0027] 2. This robotic arm adopts an electromagnetic drive method, which has a fast response speed. By controlling the coil current, the bending amplitude and gripping force of each finger segment can be precisely adjusted to meet the requirements of gripping force and positioning accuracy in gripping and transportation operations. At the same time, the output force and stiffness can be adjusted in real time. The system is easy to integrate in a lightweight manner and completely eliminates the dependence on external air sources and complex pipelines.

[0028] 3. The outer shell of the fingers of this robotic arm is made of flexible materials such as silicone, which has excellent flexibility and can adapt to the irregular shape of the target object to achieve enveloping non-destructive grasping, avoiding damage to the object surface during grasping and transportation; at the same time, the high degree of freedom of the flexible material gives the robotic arm safety, solving the problems of insufficient flexibility and unsafe human-machine interaction of traditional rigid robotic arms.

[0029] 4. The three sets of finger components of this robotic arm are distributed at 120° intervals. With the help of independently powered electromagnets, it can achieve stable and reliable three-point gripping, ensuring that the object does not slip or deviate during grasping and transportation, which significantly improves the gripping stability.

[0030] 5. The outer shell of the fingers of this robotic arm automatically resets itself after power failure due to the elasticity of the silicone material. The structure is simple, reliable, and easy to control. No additional reset mechanism is required, making it suitable for high-frequency grasping and transportation operations on assembly lines, thus reducing system complexity and maintenance costs.

[0031] 6. This robotic arm effectively overcomes the core bottlenecks of existing pneumatic flexible robotic arms, such as slow response, low rigidity, and the need for large peripheral equipment (such as air pumps, valves, and pipelines). At the same time, it makes up for the poor adaptability of traditional rigid robotic arms, and better meets the comprehensive requirements of intelligent manufacturing and human-machine collaboration for fast response, high load capacity, high safety and high adaptability, providing an ideal solution for the automated and non-destructive harvesting of fragile fruits. Attached Figure Description

[0032] Figure 1 A schematic diagram of an electromagnetically driven robotic arm;

[0033] Figure 2 This is a schematic diagram of the slide rail for an electromagnetically driven robotic arm.

[0034] Figure 3 An exploded view of the finger assembly of an electromagnetically driven robotic hand;

[0035] Figure 4 An exploded view of the first electromagnet for an electromagnetically driven robotic arm.

[0036] In the diagram: 1. Connecting plate; 1-1. Weight reduction hole; 2. Base; 2-1. Slide rail; 3. Finger assembly; 3-1. Mounting block; 3-1-1. Limiting part; 3-2. Reinforcing frame; 3-3. First permanent magnet; 3-4. First electromagnet; 3-4-1. Iron core; 3-4-2. Coil; 3-5. Second electromagnet; 3-6. Third electromagnet; 3-7. Second permanent magnet; 3-8. Finger shell; 3-8-1. Finger segment; 3-8-2. Accommodation space; 3-9. Magnet assembly. Detailed Implementation

[0037] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0038] Example 1:

[0039] An electromagnetically driven robotic arm, such as Figures 1 to 4 As shown, the device includes a connecting plate 1, a base 2, and several finger assemblies 3. The connecting plate 1 is fixedly mounted on the bottom end of the base 2, and several finger assemblies 3 are slidably mounted circumferentially on the top surface of the base 2. A driving component is connected to the base 2 at the base of each finger assembly 3, and the driving component can be fixedly mounted on the base 2. Depending on the size of the object being grasped, the driving component drives the finger assemblies 3 to retract inwards, and then drives them to bend or extend. Through the coordinated action of the three finger assemblies 3, the object is simultaneously enveloped from three directions, achieving compliant grasping and damage-free transport of the object. Preferably, the driving component is a hydraulic cylinder or a motor, suitable for driving the finger assemblies 3 to move inwards or outwards; both the connecting plate 1 and the base 2 are circular structures.

[0040] like Figure 2 As shown, a plurality of slide rails 2-1 are evenly spaced along the circumference on the top surface of the base 2. All slide rails 2-1 are radially arranged, and their inner ends are all located at the center of the base 2 and connected together. The top surfaces of the slide rails 2-1 taper inwards, allowing the finger assembly 3 to slide only radially along the slide rails 2-1. Specifically, in this embodiment, three slide rails 2-1 are provided, with an angle of 120 degrees between adjacent slide rails 2-1. The connecting plate 1 and the base 2 are spaced apart and connected by a round rod in the middle. A plurality of bolt holes are spaced along the edge of the connecting plate 1, used to adapt and connect external robotic arms or other devices of different specifications. A plurality of weight-reducing holes 1-1 are evenly spaced along the circumference of the connecting plate 1, suitable for reducing the weight of the robotic arm, achieving lightweighting, and improving the flexibility of movement during transportation and the load capacity of the robotic arm.

[0041] like Figure 3 , Figure 4As shown, the finger assembly 3 includes a finger shell 3-8 and a magnet assembly 3-9. The magnet assembly 3-9 is fixedly installed inside the finger shell 3-8, and the magnetic force of the magnet assembly 3-9 drives the bending or extension of the finger shell 3-8. The finger shell 3-8 has an elongated structure and includes several finger segments 3-8-1. The inner sides of the several finger segments 3-8-1 are connected together, and the outer sides of the several finger segments 3-8-1 are spaced apart. When grasping an object, the finger assembly 3 bends inward, that is, towards the connecting side; in this embodiment, the number of finger segments 3-8-1 is three. Specifically, the inner surface of the finger shell 3-8 has multiple micro-protrusions or wavy textures to increase the friction between the finger shell 3-8 and the surface of the object being grasped, prevent the object from slipping during the grasping process, and ensure grasping stability and transportation reliability. The finger shells 3-8 are made of flexible and elastic silicone material, preferably Ecoflex 00-30. This silicone material has a Shore hardness of 10HA to 40HA, a base layer thickness of 5mm, and exhibits flexibility and self-adaptability. It has moderate tensile strength and an elongation at break exceeding 900%, allowing for sufficient elastic deformation under electromagnetic force and complete recovery to its initial state after power is cut off. Compared to other silicone materials such as PDMS and Dragon Skin 30, Ecoflex 00-30 has lower hardness and higher elongation at break, making it more suitable for applications requiring large deformation and smooth gripping force, such as berry-like grasping. Furthermore, its short curing time (approximately 5 hours at room temperature) helps shorten the manufacturing cycle. Magnetic particles are incorporated into the material of finger shells 3-8 to enhance the electromagnetic driving force of the magnet assembly 3-9. When not driven by external force, finger shells 3-8 are either straight or slightly bent inwards. The magnet assembly 3-9 includes a first permanent magnet 3-3, a first electromagnet 3-4, a second electromagnet 3-5, a third electromagnet 3-6, and a second permanent magnet 3-7. The first permanent magnet 3-3 is fixedly installed at the base of the finger shell 3-8. The fingertip of the finger shell 3-8 has a receiving space 3-8-2, which is horizontally through-hole. The second permanent magnet 3-7 is fixedly installed inside the receiving space 3-8-2. Along the base of the finger shell 3-8 to the fingertip, three finger segments 3-8-1 are also included. The first electromagnet 3-4, the second electromagnet 3-5, and the third electromagnet 3-6 are connected in series. Each of the first electromagnet 3-4, the second electromagnet 3-5, and the third electromagnet 3-6 includes an iron core 3-4-1 and a coil 3-4-2. The iron core 3-4-1 is fixedly installed inside the coil 3-4-2. By energizing the coil 3-4-2, electromagnetic force is generated, which drives the finger shell 3-8 to achieve coordinated bending movements of multiple joints, so that the finger shell 3-8 can conform to the irregular shape of the object and perform a soft, enveloping grasp.The coil 3-4-2 of the second electromagnet 3-5 is wound in the opposite direction to the coil 3-4-2 of the first electromagnet 3-4 and the third electromagnet 3-6. When current is applied in the same direction, adjacent electromagnets will generate magnetic fields in opposite directions, thus producing alternating electromagnetic attraction and repulsion, driving each finger segment 3-8-1 to bend in a coordinated manner. The magnetic poles of the first permanent magnet 3-3 and the second permanent magnet 3-7 are arranged opposite to each other. Furthermore, the two sides of the finger segment 3-8-1 are covered with a film, which is suitable for fixing the first electromagnet 3-4, the second electromagnet 3-5, and the third electromagnet 3-6, and preventing the iron core 3-4-1 and the coil 3-4-2 from falling off. Specifically, the iron core 3-4-1 is made of soft magnetic material, which has the characteristics of high permeability and low remanence. It can be rapidly magnetized when energized and rapidly demagnetized when de-energized, thereby ensuring the rapid response of the finger assembly 3 in bending and resetting. The coil 3-4-2 is made of enameled wire, which has good insulation and conductivity. The coils 3-4-2 of the first electromagnet 3-4, the second electromagnet 3-5, and the third electromagnet 3-6 are all independently powered to achieve independent control of the bending amplitude of each finger segment 3-8-1. When energized, by switching the first electromagnet 3-4, the second electromagnet 3-5, and the third electromagnet 3-6 on and off, and adjusting the magnitude and direction of the current, the magnetic fields generated by the first electromagnet 3-4, the second electromagnet 3-5, and the third electromagnet 3-6 interact with the first permanent magnet 3-3 and the second permanent magnet 3-7, generating electromagnetic attraction or repulsion. This drives the finger shell 3-8 to bend or extend, thereby achieving independent adjustment of the bending amplitude and grasping force of each joint of each finger component 3, and precisely controlling the grasping position and posture of the object during grasping and transportation. When de-energized, the finger shell 3-8 returns to its initial straight state due to its own elasticity, releasing the object and completing the placement.

[0042] like Figure 3 As shown, the finger assembly 3 also includes a mounting block 3-1 and a reinforcing frame 3-2. Both the mounting block 3-1 and the reinforcing frame 3-2 are rectangular frame structures. The root of the finger shell 3-8 and the first permanent magnet 3-3 are fixedly installed inside the reinforcing frame 3-2. The reinforcing frame 3-2 is fixedly installed inside the mounting block 3-1. The mounting block 3-1 has a protruding limiting part 3-1-1. The limiting part 3-1-1 and the mounting block 3-1 are spaced apart. The limiting part 3-1-1 and the mounting block 3-1 are connected together by a connecting rod. The length and width of the connecting rod correspond to the width and thickness of the top surface of the slide 2-1. The size of the limiting part 3-1-1 corresponds to the internal size structure of the slide 2-1. The limiting part 3-1-1 is slidably installed inside the slide 2-1. When grasping, the spacing between several finger assemblies 3 is first adjusted, and then the finger assemblies 3 are driven to bend to accurately grasp objects of different sizes.

[0043] To optimize the bending performance of finger assembly 3, simulation analyses were conducted on two key structural parameters: the thickness of the finger shell at the root of 3-8 and the spacing between adjacent finger segments 3-8-1. For the thickness of the finger shell at the root of 3-8, finger models with thicknesses of 3mm, 4mm, 5mm, and 6mm were established, with the spacing between adjacent finger segments 3-8-1 uniformly set to 4mm. Simulation results show that as the thickness of the finger shell at the root of 3-8 increases, the bending angle of finger assembly 3 under the same electromagnetic force gradually decreases; the bending angle is larger at thicknesses of 3mm and 4mm, but the silicone layer exhibits excessive tensile deformation; the deformation is less different at thicknesses of 5mm and 6mm. Considering both bending capability and structural stability, the optimal bottom layer thickness was determined to be 5mm. For the spacing between adjacent finger segments 3-8-1, finger models with spacings of 2mm, 4mm, and 6mm were established, with the bottom layer thickness fixed at 5mm. Simulation results show that when the spacing is 2mm, the bending angle of finger segments 3-8 is approximately 20.7°; when the spacing is 4mm, the bending angle increases by approximately 2.2°; and when the spacing is 6mm, the difference in bending angle between 3-8 and 4mm is only 0.3°. Furthermore, increasing the spacing helps to disperse stress concentration during the bending process. Considering both the bending angle and the stability of the electromagnet, the spacing between adjacent finger segments 3-8-1 is determined to be 4mm.

[0044] Under the conditions that the thickness of the finger shell 3-8 root is 5mm, the spacing between adjacent finger segments 3-8-1 is 4mm, and the number of finger segments 3-8-1 is 3, the bending motion of the finger assembly 3 was further simulated and analyzed when the applied currents were 0.5A, 1.0A, and 1.5A. The simulation results show that when the current is 0.5A, the total bending angle of the finger assembly 3 is 26.3°, the angle between the first electromagnet 3-4 and the second electromagnet 3-5 is 25.3°, and the angle between the second electromagnet 3-5 and the third electromagnet 3-6 is 25.1°; when the current increases to 1.0A, the total bending angle reaches 35.7°, and the angles between adjacent electromagnets are 31.4° and 33.7°, respectively; when the current increases to 1.5A, the total bending angle is 39.5°, and the angles between adjacent electromagnets are 32.3° and 37.2°, respectively. As the current increases, the bending angle of finger assembly 3 increases, but the increment of the bending angle gradually decreases. This is because the increased spacing between adjacent electromagnets slows down the growth of the repulsive force, while the deformation resistance of the silicone layer increases. Simulation results of the displacement of the finger assembly 3 endpoints also show that the displacement in the negative X-axis and positive Y-axis directions increases with the increase of current, but the increment of Y-axis displacement is small in the range of 1.0A to 1.5A.

[0045] The finger assembly 3 employs a three-finger segment 3-8-1 series structure, with different thicknesses of coating layers at the bottom of each segment. To quantitatively evaluate the influence of coating thickness on the electromagnetic driving force, a three-dimensional electromagnetic model of the finger assembly 3 was constructed in the ANSYS Maxwell environment. In the model, the iron core 3-4-1 has a diameter of 8 mm, the coil 3-4-2 has a diameter and height of 19.6 mm and 12 mm respectively, the coil 3-4-2 has 480 turns, and the wire diameter is 0.35 mm; the first permanent magnet 3-3 and the second permanent magnet 3-7 have a diameter of 12 mm and a height of 2 mm. The relative permeability of the silicone material was set to 0.999, and the volume conductivity was 5.8 × 10⁻⁶. 7 S / m, Young's modulus 1.2×10 11 Pa, Poisson's ratio 0.38. By applying turn-ampere excitation, the electromagnetic repulsion force output by each core 3-4-1 was calculated under different bottom layer coating thicknesses (0.5 mm, 1.0 mm, 1.5 mm) for different finger segments 3-8-1. Simulation results show that when the coating thickness is 0.5 mm, 1.0 mm, and 1.5 mm, the output force of the top core 3-4-1 is 191.70 mN, 173.29 mN, and 159.20 mN, respectively, and the output force of the bottom core 3-4-1 is 207.94 mN, 181.51 mN, and 160.23 mN, respectively. The electromagnetic force decreases with increasing coating thickness, providing accurate load input for subsequent kinematic analysis.

[0046] The repulsive force of the iron core 3-4-1 obtained from electromagnetic simulation was used as the driving load and imported into ABAQUS for explicit dynamic analysis. The silicone material of the finger shell 3-8 adopted the Yeoh hyperelastic constitutive model, with first-order coefficients C. 10 =0.11MPa, second-order coefficient C 20 =0.02MPa. The boundary conditions are set as follows: the uppermost surface of finger component 3 is completely fixed, the electromagnet is defined as a rigid body with a mass point applied at its center of gravity, and the electromagnetic force is applied to the end face of the electromagnet in the form of pressure. The mesh uses 1mm tetrahedral elements of type C3D10H (secondary ten-node tetrahedral hybrid element) to accommodate large deformation analysis of incompressible hyperelastic materials. To simulate the gradual opening process of finger component 3, an iterative coupling strategy is adopted: the deformed finger component 3 model is re-imported into Maxwell to update the electromagnetic force, and the calculation is repeated until the relative error of deformation between two adjacent iterations is less than 1×10. -4 .

[0047] Kinematic simulation results show that the thickness of the wrapping membrane has a significant impact on the bending posture and stress distribution of the finger assembly 3. When the membrane thickness is 1.5 mm, the angle between the top finger segment 3-8-1 and the middle finger segment 3-8-1 is approximately 22°, the angle between the middle finger segment 3-8-1 and the bottom finger segment 3-8-1 is approximately 17°, and the total bending angle of the finger assembly 3 is approximately 25°. When the membrane thickness decreases to 1.0 mm, the corresponding angles increase to 28° and 20° respectively, and the total bending angle is approximately 48°. In terms of stress distribution, the stress is mainly concentrated at the junction of finger segments 3-8-1 during operation. When the membrane thickness is 0.5 mm, the maximum stress in finger segment 3-8-1 reaches 0.17 MPa, and the stress concentration phenomenon in the fingertip area is severe. When the membrane thickness is 1.0 mm, the stress distribution is more uniform, and the degree of stress concentration is significantly improved. When the membrane thickness is 1.5 mm, the bending angle is too small, affecting the grasping range. In addition, the contact force change rate was calculated based on the change in fingertip force during the opening of finger component 3. The change rate under the three thicknesses did not exceed the damage threshold of 0.082 N / s, with the largest at 0.5 mm (0.051 N / s) and the smallest at 1.5 mm (0.042 N / s).

[0048] To evaluate the heat accumulation of the finger under continuous energized operation, a multiphysics simulation was performed using a coupled ANSYS Maxwell electromagnetic field and transient thermal analysis method. First, the eddy current losses generated by the alternating magnetic field in coil 3-4-2 and iron core 3-4-1 were calculated in the eddy current field, and the loss results were imported as volumetric heat loads into the transient thermal analysis module. Material thermal properties were assigned to coil 3-4-2, iron core 3-4-1, and finger shell 3-8 respectively, and the contact interface was defined as a binding constraint to ensure continuous heat flow. The meshing strategy was: 1 mm for coil 3-4-2, 0.5 mm for iron core 3-4-1, and 2 mm for finger shell 3-8. Boundary conditions were set to convective heat transfer between the entire manipulator model and the air, with a heat transfer coefficient of 50 W / (m²·℃) and an ambient temperature of 22℃. The simulation duration was 200 s, with the time step optimized to balance computational accuracy and convergence.

[0049] Thermal simulation results show that under continuous energization for 200 seconds, the temperature rise of the finger assembly 3 is mainly concentrated in the core heating areas of coil 3-4-2 and iron core 3-4-1, and diffuses to the surrounding area via heat conduction. The temperature rise of the fingertip portion of the finger shell 3-8 is very small and will not have a thermal impact on the manipulated object. The temperature parameters for different coating thicknesses are as follows: with a coating thickness of 0.5 mm, the highest local temperature is 34.73℃, the lowest temperature is 22.42℃, and the average temperature is 33.49℃; with a coating thickness of 1.0 mm, the highest temperature is 34.29℃, the lowest temperature is 22.38℃, and the average temperature is 33.18℃; with a coating thickness of 1.5 mm, the highest temperature is 33.85℃, the lowest temperature is 22.35℃, and the average temperature is 32.77℃. It can be seen that as the coating thickness increases, the overall temperature level of the finger shell 3-8 decreases, indicating that increasing the coating thickness can enhance the thermal resistance effect of the structure and suppress the conduction of heat to the end effector.

[0050] Considering the bending performance of finger component 3, the stress concentration of finger segment 3-8-1, the rate of change of contact force, and thermal safety performance, a film thickness of 0.5 mm results in a larger bending angle, severe stress concentration, and the highest average temperature. A film thickness of 1.5 mm provides the best thermal safety, but the bending angle is insufficient. A film thickness of 1.0 mm results in a larger bending angle, more uniform stress distribution, a moderate rate of change of contact force, and an average temperature of 33.18℃ within a controllable range. Therefore, the optimal thickness of the bottom film of finger segment 3-8-1 is determined to be 1.0 mm. Through the above series of simulation experiments, it can be concluded that the optimal thickness of the root of finger component 3 is 5 mm, the spacing between adjacent finger segments 3-8-1 is 4 mm, and the optimal thickness of the bottom film is 1.0 mm.

[0051] After grasping the object, the external robotic arm moves it to the target position. During the movement, the coils 3-4-2 are kept energized, maintaining the bent posture of the finger assembly 3 to ensure the object does not slip or deviate during transport. Upon reaching the target position, according to a preset plan, the current of each coil 3-4-2 is precisely adjusted to control the bending amplitude of each finger segment 3-8-1, allowing the finger assembly 3 to open appropriately and accurately place the object in the target position. Then, the power supply to each coil 3-4-2 is cut off, and the finger shells 3-8 return to their initial straight state due to the elasticity of the silicone material, fully opening the finger assembly 3. The robotic arm returns to its initial state, ready for the next grasp.

[0052] By repeating the above-described processes of grasping, transporting, placing, and resetting, stable grasping, precise placement, and reliable transport of objects can be achieved one by one. Throughout the operation, the energization, current magnitude, and direction of each coil 3-4-2 can be independently adjusted, thereby precisely controlling the bending amplitude and grasping force of each finger component 3's finger shells 3-8 to adapt to objects of different sizes and shapes, ensuring neat placement and reliable transport. Actual grasping tests have verified that this robotic arm can achieve varying degrees of bending within a current range of 0.5A to 1.5A, completing the grasping action instantly upon energization, demonstrating a fast response speed.

[0053] This invention also conducted a non-destructive blueberry gripping test:

[0054] One hundred fresh, uniformly ripe blueberries, measuring 13-16mm in size, were selected and grasped using this robotic arm. The robotic arm adjusts the electromagnetic drive force in real-time via current, stabilizing the fingertip contact force below 0.68N. In 100 consecutive grasping cycles, the success rate reached 99%. Inspection of all blueberries after processing revealed no mechanical damage such as skin dents, cracks, or bloom loss caused by gripping. This embodiment fully verifies the robotic arm's ability to achieve stable grasping and damage-free transport through precise current-controlled output force and stiffness.

[0055] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An electromagnetically driven robotic arm, characterized in that, include: The base (2) is a disc-shaped structure, and the base (2) has several radially arranged slides (2-1) spaced along the circumference. Several finger components (3) are radially slidably installed in several of the slides (2-1) at their bottom ends; A magnet assembly (3-9) is fixedly installed inside the finger assembly (3), and the finger assembly (3) is driven to bend or extend by the magnet assembly (3-9); Several of the finger components (3) slide toward each other and converge, and are driven by the magnet components (3-9) to bend toward each other to achieve a grasping action.

2. The electromagnetically driven robotic arm according to claim 1, characterized in that, It also includes a finger shell (3-8) made of a flexible material. The finger shell (3-8) includes a number of finger segments (3-8-1) spaced apart. The inner sides of the finger segments (3-8-1) are connected to each other, and the outer sides are left with gaps. The magnet assembly (3-9) is fixedly installed inside the finger segment (3-8-1).

3. The electromagnetically driven robotic arm according to claim 2, characterized in that, The inner surface of the finger shell (3-8) is provided with magnetic particles; The inner surface of the finger shell (3-8) is textured with raised patterns.

4. The electromagnetically driven robotic arm according to claim 2 or 3, characterized in that, The magnet assembly (3-9) includes a pair of permanent magnets and a plurality of electromagnets. The pair of permanent magnets are respectively fixedly installed at both ends of the finger assembly (3), and the plurality of electromagnets are respectively fixedly installed in the plurality of finger segments (3-8-1) and located between the pair of permanent magnets. All of the electromagnets are energized.

5. The electromagnetically driven robotic arm according to claim 4, characterized in that, The surface of the finger segment (3-8-1) is covered with a membrane, which is suitable for limiting the electromagnet.

6. The electromagnetically driven robotic arm according to claim 5, characterized in that, The magnetic fields of adjacent electromagnets are in opposite directions; The magnetic poles of the pair of permanent magnets are arranged opposite each other.

7. The electromagnetically driven robotic arm according to claim 2 or 3, characterized in that, The finger assembly (3) further includes a mounting block (3-1) and a reinforcing frame (3-2), both of which are rectangular frame structures; The root of the finger shell (3-8) is fixedly installed inside the reinforcing frame (3-2), and the reinforcing frame (3-2) is fixedly installed inside the mounting block (3-1).

8. The electromagnetically driven robotic arm according to claim 7, characterized in that, The mounting block (3-1) has a limiting part (3-1-1) which is located inside the slide rail (2-1); The shape of the limiting part (3-1-1) corresponds to that of the slide (2-1).

9. The electromagnetically driven manipulator according to any one of claims 1 to 3, characterized in that, The lower end face of the base (2) is fixedly mounted with a connecting plate (1), which is suitable for connecting external control equipment.

10. The electromagnetically driven robotic arm according to claim 9, characterized in that, The connecting plate (1) has several weight-reducing holes (1-1) spaced apart.

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