Mechanical arm system based on force driving and force sensing decoupling

Abstract

The application discloses a mechanical arm system based on force driving and force sensing decoupling, which comprises a support assembly, a gripper base, a six-dimensional force sensor and a hydraulic sensor, wherein the support assembly is provided with a main-end hydraulic cylinder and a first three-way joint, the main-end hydraulic cylinder is communicated with the first three-way joint; the gripper base is provided with a gripper, two gripper fingers in the gripper are movable and arranged on the gripper base; the gripper base is further provided with a second three-way joint and two from-end hydraulic cylinders, the second three-way joint is communicated with the first three-way joint and the from-end hydraulic cylinders, the output ends of the from-end hydraulic cylinders are connected with corresponding gripper fingers to drive the corresponding gripper fingers to move; the six-dimensional force sensor is connected between the support assembly and the gripper base; and the hydraulic sensor is communicated with the first three-way joint. Thus, the application solves the problem of lack of force sensation information, realizes complete decoupling of driving force and sensing force, improves the purity and quality of six-dimensional force sensation data, and improves the large-scale diversified data acquisition efficiency and scene adaptability.

Description

Technical Field

[0001] This application relates to the field of robotic arm technology, and in particular to a robotic arm system based on the decoupling of force drive and force sensing. Background Technology

[0002] Current technologies for collecting robotic arm operation data can be mainly divided into the following three categories, each with its own limitations: (1) Kinematic teaching: The operator directly drags the physical robotic arm in "zero gravity" or "compliant" mode to perform the task, and collects the operation data through joint encoders, end effector six-dimensional force sensors and cameras. The limitation is that the robotic arm still has a large inertia and friction even in the compensation mode, which causes the collected data to have obvious jitter and introduces huge background noise into the force information; the teaching process is difficult to carry out in open or narrow real environments, and the scene adaptability is poor.

[0003] (2) Teleoperation schemes: These schemes involve remotely controlling a slave robotic arm via a master device to complete tasks. They are mainly divided into two categories: homogeneous and heterogeneous. Homogeneous teleoperation uses a robotic arm with the same configuration as the slave arm. Its limitations are: the equipment is large and bulky, costly, and most schemes do not have a force feedback mechanism, so the operator cannot perceive the force applied to the slave arm. Redirecting teleoperation (heterogeneous teleoperation) captures hand poses and maps them to the robotic arm. Its limitations are: limited operational accuracy, high communication latency, and also a lack of force feedback. Both teleoperation schemes heavily rely on the slave robotic arm, resulting in equipment redundancy, low data acquisition efficiency, and limitations to laboratory scenarios. Due to the lack of real environmental interaction force feedback, the teaching trajectory often deviates from real operating habits, resulting in low data quality.

[0004] (3) Portable handheld gripper: Early solutions focused on acquiring visual information, such as recording trajectories through motion capture systems, collecting RGBD data (including color images and depth information), estimating end-effector pose using visual SLAM (Simultaneous Localization and Mapping) methods, or collecting data using tracking cameras. These solutions significantly improved the portability of the device, but none of them integrated force perception. Moreover, SLAM pose estimation is highly dependent on environmental texture features, and significant pose drift is easily generated in scenes with missing textures, such as white walls, affecting the accuracy of data acquisition. Furthermore, some solutions installed a six-dimensional force sensor on the wrist for mechanical perception, but the driving force and the perceived force are coupled at the physical level, which can lead to mechanical contamination and introduce nonlinear interference noise into the wrist sensor. Another type of solution places a miniature force sensor at the base of the fingertip to avoid the wrist coupling problem; however, this sensor has inherent defects such as fragile structure, limited range, obvious nonlinear output, and insufficient measurement accuracy, making it difficult to meet the long-term, high-intensity data acquisition needs in daily production and life scenarios or complex physical interaction tasks.

[0005] In summary, existing technologies suffer from insufficient purity and realism of force information and inadequate scene adaptability. Summary of the Invention

[0006] This application aims to address at least one of the technical problems existing in the prior art. Therefore, the purpose of this application is to propose a robotic arm system based on the decoupling of force drive and force perception, aiming to solve the problems of insufficient purity and realism of force perception information and insufficient scene adaptability in robotic arms.

[0007] This application proposes a robotic arm system based on the decoupling of force drive and force sensing. The robotic arm system includes a support assembly, a gripper base, a six-dimensional force sensor, and a hydraulic sensor. The support assembly is equipped with a main hydraulic cylinder and a first three-way connector, wherein the main hydraulic cylinder is connected to the first three-way connector. The gripper base is equipped with a gripper, and two gripping fingers of the gripper are movable and positioned on the gripper base. The gripper base is also equipped with a second three-way connector and two slave hydraulic cylinders, wherein the second three-way connector is connected to the first three-way connector and the two slave hydraulic cylinders, and the output end of the slave hydraulic cylinder is connected to the corresponding gripping finger to drive the corresponding gripping finger to move. The six-dimensional force sensor is connected between the support assembly and the gripper base. The hydraulic sensor is connected to the first three-way connector.

[0008] The robotic arm system of this application solves the problem of missing force information in compliant robotic arm operation by setting up a six-dimensional force sensor, providing the robot with complete multimodal data such as vision, wrist six-dimensional force, end effector position, and gripper opening and closing distance. Through innovation in physical structures such as hydraulic drive, the driving force and sensing force are completely decoupled, fundamentally improving the purity and quality of the wrist six-dimensional force data, and solving the problem of poor force data quality and physical coupling of driving force / sensing force. Through the lightweight and portable gripper structure design, the dependence on physical robotic arms and fixed bases is eliminated, enabling efficient and large-scale data acquisition anytime and anywhere, significantly improving the diversity of datasets, and solving the problems of efficiency and scenario limitations in large-scale and diverse data acquisition.

[0009] According to some embodiments of this application, each of the two gripper fingers is provided with a rack, and the gripper base is provided with a gear, wherein the gear meshes with the two racks respectively.

[0010] According to some embodiments of this application, the robotic arm system also includes an angle encoder connected to a gear to detect the rotation angle of the gear.

[0011] According to some embodiments of this application, the gripper base is further provided with two spring assemblies, which are connected to the corresponding gripper fingers to drive the corresponding gripper fingers to reset.

[0012] According to some embodiments of this application, the spring assembly includes a mounting post and a constant force spring, the mounting post being rotatably connected to the gripper base; the constant force spring is wound around the mounting post, and the outer end of the constant force spring is connected to the corresponding gripper finger.

[0013] According to some embodiments of this application, the robotic arm system further includes a first camera and a second camera, which are respectively disposed on the gripper base. The detection end of the first camera is disposed facing the working area of ​​the gripper, and the detection end of the second camera is disposed facing the non-working area of ​​the gripper.

[0014] According to some embodiments of this application, the first camera is configured as a depth camera and the second camera is configured as a SLAM camera.

[0015] According to some embodiments of this application, the gripper base is provided with two first optical axes and two second optical axes, wherein the gripper fingers connect the corresponding first optical axes and the two second optical axes.

[0016] According to some embodiments of this application, the inner end of the finger is slidably connected to the first optical axis and the second optical axis respectively, and the width of the end of the finger is smaller than the width of the inner end of the finger.

[0017] According to some embodiments of this application, the clip finger is provided with three connecting holes for connecting to the corresponding first optical axis or second optical axis; wherein, the three connecting holes are located at the three vertices of the triangle.

[0018] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0019] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the structure of a robotic arm system according to some embodiments of this application; Figure 2 This is a rear-view structural schematic diagram of a robotic arm system according to some embodiments of this application; Figure 3 This is an exploded view of the structure of a robotic arm system according to some embodiments of this application; Figure 4 This is an exploded view of the gripper structure of a robotic arm system according to some embodiments of this application; Figure 5 This is a comparison chart of the test results of decoupling tests between the robotic arm systems of some embodiments of this application and the prior art; Figure 6 This is a schematic diagram showing the linearity test results of a robotic arm system according to some embodiments of this application; Figure 7 This is a schematic diagram showing the frequency response test results of a robotic arm system according to some embodiments of this application; Figure 8 This is a schematic diagram showing the reproduction test results of a robotic arm system according to some embodiments of this application.

[0020] Figure label: Support component 10; gripper base 20; six-dimensional force sensor 30; gripper finger 40; Main hydraulic cylinder 51; First tee fitting 52; Second tee fitting 53; Slave hydraulic cylinder 54; Hydraulic pipeline 55; First optical axis 61; Second optical axis 62; Rack 63; Gear 64; Angle encoder 65; Spring assembly 66; First camera 71; Second camera 72. Detailed Implementation

[0021] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0022] The following is for reference. Figures 1-4This application describes a robotic arm system based on the decoupling of force drive and force sensing according to embodiments of the present application.

[0023] This application proposes a robotic arm system based on the decoupling of force drive and force sensing. The robotic arm system includes a support assembly 10, a gripper base 20, a six-dimensional force sensor 30, and a hydraulic sensor. The support assembly 10 is equipped with a main hydraulic cylinder 51 and a first three-way connector 52, wherein the main hydraulic cylinder 51 is connected to the first three-way connector 52. The gripper base 20 is equipped with a gripper, and the two gripping fingers 40 of the gripper are movable and disposed on the gripper base 20. The gripper base 20 is also equipped with a second three-way connector 53 and two slave hydraulic cylinders 54, wherein the second three-way connector 53 is connected to the first three-way connector 52 and the two slave hydraulic cylinders 54, and the output end of the slave hydraulic cylinder 54 is connected to the corresponding gripping finger 40 to drive the corresponding gripping finger 40 to move. The six-dimensional force sensor 30 is connected between the support assembly 10 and the gripper base 20. The hydraulic sensor is connected to the first three-way connector 52.

[0024] The support assembly 10 serves as the mounting and operating foundation for the gripper, acting as the master end and the gripper as the slave end. The gripper base 20 is connected to the support assembly 10 via a six-dimensional force sensor 30. The six-dimensional force sensor 30 detects the force and torque of the gripper in three orthogonal directions in space, collecting force information. The master-end hydraulic cylinder 51 on the support assembly 10 is the power source. The first three-way connector 52 and the second three-way connector 53 each have three interconnected connection ports for hydraulic medium transmission. The master-end hydraulic cylinder 51 is connected to one connection port of the first three-way connector 52 via a hydraulic pipeline 55. The other connection port of the first three-way connector 52 is connected to one connection port of the second three-way connector 53 via a hydraulic pipeline 55. The other two connection ports of the second three-way connector 53 are connected to two slave-end hydraulic cylinders 54 via hydraulic pipelines 55. Figure 1 , Figure 2 As shown, at the main end, the operator can drive the main end hydraulic cylinder 51 through a pinching action. The main end hydraulic cylinder 51 delivers hydraulic medium to the second three-way connector 53 through the first three-way connector 52. The second three-way connector 53 further delivers hydraulic medium to two slave end hydraulic cylinders 54 located on both sides of the gripper base 20. The output ends of the two slave end hydraulic cylinders 54 are respectively connected to the corresponding gripping fingers 40. Under the pressure of the hydraulic medium, the two gripping fingers 40 are synchronously driven to move towards or away from each other, adjusting the opening and closing degree of the gripper, and realizing the clamping and releasing of the workpiece at the slave end. A hydraulic sensor is connected to one of the connection ports of the first three-way connector 52 to monitor the internal pressure of the system pipeline in real time.

[0025] The second three-way component 53 is disposed on the gripper base 20, and the first three-way component 52 is disposed on the support component 10 and rigidly connected to the support component 10, forming a hydraulic bypass topology design. This allows the input force flow of the main hydraulic cylinder 51 to be directly guided to the handle frame (i.e., the structural frame composed of the support component 10 and the gripper base 20) through the support component 10 and the double three-way (i.e., the first three-way component 52 and the second three-way component 53) fixing mechanism, so that it completely bypasses the force support point of the six-dimensional force sensor. After the hydraulic line 55 crosses the six-dimensional force sensor 30, it is first rigidly anchored at the first tee member 52. This means that the force flow generated by the initial stress of the hydraulic line 55's deformation or the dynamic vibration during movement will be blocked at the support component 10 and directed to the handle frame, without passing through the intermediate six-dimensional force sensor 30. This bypass topology ensures that the signal recorded by the six-dimensional force sensor 30 originates only from the real interaction force between the gripper and the environment, achieving physical-level force decoupling. This prevents direct mechanical interference to the six-dimensional force sensor 30 caused by the elasticity, vibration, or the instructor's pinching action of the hydraulic line. This means that the sensor can capture only environmental feedback, ensuring the purity and signal-to-noise ratio of the interaction force data from the source, providing high-quality underlying support for the model to learn real physical laws.

[0026] Furthermore, this application utilizes the incompressible properties of hydraulic fluid under quasi-static conditions to create a highly rigid force transmission loop between the master and slave ends, achieving extremely high transparency of clamping force perception. This means that the clamping situation at the slave end (the front end of the gripper) can be clearly felt at the master end (the hand end). The hydraulic transmission system enables highly transparent bidirectional force feedback of the clamping force, significantly improving the naturalness of the teaching operation. The operator can subtly perceive the stiffness change at the moment of contact and the force fluctuations during continuous clamping. This tactile feedback not only makes the teaching actions more in line with natural human operating intuition but also significantly reduces jitter noise in the trajectory, ensuring a high degree of unity between posture and force perception modes at the dynamic level. For example, in experiments involving the gripping of fragile items (such as eggs, light bulbs, etc.), due to the extremely high transmission stiffness and low friction characteristics of the hydraulic system, the operator can directly and subtly perceive the moment of contact and the stiffness change of the object after compression through the pinching sensation of the hand, thus adjusting the applied force as if using natural fingers.

[0027] The robotic arm system of this application solves the problem of missing force information in compliant robotic arm operation by setting a six-dimensional force sensor 30, providing the robot with complete multimodal data such as vision, wrist six-dimensional force, end effector position, and gripper opening and closing distance; through innovation in physical structures such as hydraulic drive, the driving force and sensing force are completely decoupled, fundamentally improving the purity and quality of the wrist six-dimensional force data, and solving the problem of poor force data quality and physical coupling of driving force / sensing force; through the lightweight and portable gripper structure design, the dependence on physical robotic arms and fixed bases is eliminated, enabling efficient and large-scale data acquisition anytime and anywhere, significantly improving the diversity of datasets, and solving the problems of efficiency and scenario limitations in large-scale and diverse data acquisition.

[0028] In some embodiments, the support component 10 is constructed as an L-shaped connector, and part of the support component 10 is constructed as an operating handle. The operating handle integrates the aforementioned main hydraulic cylinder 51. The operator applies force to the main hydraulic cylinder 51 by naturally pinching the handle with their thumb and forefinger, which directly drives the hydraulic rod, simulating a realistic grasping feel. The detection data from the hydraulic sensor can serve as an auxiliary mode of pinching force, which, together with the environmental interaction force captured by the six-dimensional force sensor 30, constitutes a complete force perception description feature, enabling main-end interaction and real-time monitoring.

[0029] According to some embodiments of this application, each of the two gripping fingers 40 is provided with a rack 63, and the gripper base 20 is provided with a gear 64, wherein the gear 64 is meshed with the two racks 63 respectively. Figure 3 , Figure 4 As shown, in this embodiment, the gear 64 is disposed between the two racks 63 and meshes with them respectively. The two gripper fingers 40 form an antagonistic fit through the corresponding racks 63 and the same gear 64 in the center, which can achieve precise concentric synchronous opening and closing.

[0030] According to some embodiments of this application, the robotic arm system further includes an angle encoder 65, which is connected to the gear 64 to detect the rotation angle of the gear 64. In this embodiment, a miniature angle encoder 65 is integrated at the rear end of the gear 64 shaft, which can capture the rotation angle of the gear 64 in real time and with high precision, and convert it into the opening and closing width modal data of the gripper.

[0031] According to some embodiments of this application, the gripper base 20 is further provided with two spring assemblies 66, which are connected to the corresponding gripper fingers 40 to drive the corresponding gripper fingers 40 to reset. Figure 2As shown, in this embodiment, by setting the spring assembly 66, the spring restoring force can be used to drive the gripper fingers 40 to reset, solving the problem of automatic rebound of the gripper in the non-forced state. Here, the non-forced state of the gripper means that the main end hydraulic cylinder 51 releases the operating force; the forced state of the gripper means that the operating force is applied to the main end hydraulic cylinder 51 to use hydraulic control to bring the gripper fingers 40 closer together to grip the item.

[0032] According to some embodiments of this application, the spring assembly 66 includes a mounting post and a constant force spring. The mounting post is rotatably connected to the gripper base 20. The constant force spring is wound around the mounting post, and its outer end is connected to the corresponding gripper finger 40. In this embodiment, one end of the constant force spring is fixed to the back of the gripper finger 40, and the other end is wound around the mounting post of the gripper base 20. When the main hydraulic cylinder 51 drives the gripper fingers 40 to move closer to each other, the gripper fingers 40 pull the constant force spring, increasing its elastic restoring force. When the gripper is not under force, the elastic restoring force of the constant force spring pulls the gripper fingers 40 to move to the sides to reset. Furthermore, the mounting post is rotatably connected to the base by screws, rather than being rigidly fixed. When the gripper finger 40 moves, the mounting post rotates synchronously with the expansion or contraction of the constant force spring, effectively eliminating the internal stress fluctuations caused by traditional torsion springs or tension springs, giving the gripper finger 40 a uniform operating feel throughout its entire stroke, and greatly improving the continuity of the instructor's movements during data acquisition.

[0033] According to some embodiments of this application, the robotic arm system further includes a first camera 71 and a second camera 72, which are respectively disposed on the gripper base 20. The detection end of the first camera 71 is directly opposite the working area of ​​the gripper 40, and the detection end of the second camera 72 is directed towards the non-working area of ​​the gripper 40. Figure 1 As shown, in this embodiment, by setting the first camera 71 to capture the working area between the fingers 40, the geometric features of the object, the contact relationship between the fingers 40 and the object, and the environmental depth point cloud can be recorded; by setting the second camera 72 to capture the environment outside the working area of ​​the fingers 40, the texture features in the environment can be obtained, thereby improving the positioning accuracy and pose tracking robustness of the system in complex environments.

[0034] According to some embodiments of this application, the first camera 71 is configured as a depth camera, and the second camera 72 is configured as a SLAM camera. In this embodiment, the depth camera is used to achieve depth perception, and the SLAM camera is used to enhance localization; the two work together to achieve high-precision pose acquisition.

[0035] Furthermore, the detection end of the first camera 71 is set at an angle downwards, aiming at the working area of ​​the gripper 40 to take a top-down shot; the detection end of the second camera 72 is set at an angle upwards, taking a shot at an "upward" angle. The logic behind this unique layout is that in many indoor tasks, desktops or walls often lack sufficient texture information, which can easily cause visual SLAM algorithms to drift; the upward-angled view of the second camera 72 can capture more textured features, thereby significantly improving the system's positioning accuracy and pose tracking robustness in complex environments.

[0036] This application employs an innovative dual-camera layout, particularly the "oblique upward" SLAM camera perspective, to actively capture more textured information about ceilings, lighting fixtures, or architectural structures above the space. This differentiated visual observation strategy significantly enhances the system's pose tracking stability in various complex unstructured environments, ensuring the continuity and reliability of spatial coordinate acquisition.

[0037] Furthermore, a camera bracket is provided on the gripper base 20, and the first camera 71 and the second camera 72 are respectively connected to the camera bracket; and adjustment components are respectively provided between the first camera 71 and the camera bracket and between the second camera 72 and the camera bracket, the adjustment components being used to adjust the angles of the first camera 71 and the second camera 72 respectively.

[0038] According to some embodiments of this application, the gripper base 20 is provided with two first optical axes 61 and two second optical axes 62, wherein the gripper fingers 40 connect the corresponding first optical axes 61 and the two second optical axes 62. For example... Figures 1-4 As shown, in this embodiment, a first optical axis 61 and a second optical axis 62 are provided to serve as the mounting and sliding base for the clip finger 40 and to guide the movement of the clip finger 40. The two second optical axes 62 are shared optical axes for the two clip fingers 40, ensuring alignment consistency; the first optical axis 61 is an independent optical axis corresponding to a single clip finger 40, thus enhancing the torsional stiffness of the single clip finger 40.

[0039] According to some embodiments of this application, the gripper finger 40 is provided with three connecting holes for connecting to the corresponding first optical axis 61 or second optical axis 62; wherein, the three connecting holes are located at the three vertices of a triangle. In this embodiment, in some embodiments, the gripper finger 40 is connected to the first optical axis 61 and the second optical axis 62 by providing connecting holes. The three connecting holes are located at the three vertices of the triangle, forming a "triangle" constraint, which can effectively counteract the lateral torque during the gripping process and prevent the gripper finger 40 from swaying or jamming. In some embodiments, a linear bearing is provided in the connecting hole of the gripper finger 40, and the linear bearing is connected to the first optical axis 61 and the second optical axis 62.

[0040] Furthermore, the inner end of the clip 40 is provided with a first connecting part and a second connecting part, which are integrated together. The first and second connecting parts are respectively provided with corresponding connecting holes. The first connecting part is connected to two second optical axes 62, and the second connecting part is connected to the first optical axis 61. The second connecting part extends parallel to the first optical axis 61 and is provided with the aforementioned rack 63. Both ends of the second connecting part are provided with linear bearings to enhance the stability of the sliding connection between the rack 63 and the first optical axis 61, forcibly restricting the movement of the rack 63 to a linear track. This avoids problems such as tooth skipping or loose meshing that may occur between the gear 64 and the rack 63 under high load or high dynamic operation, ensuring smooth transmission and linearity of the opening / closing measurement.

[0041] In some embodiments, the gripper finger 40 is provided with a groove, and the push rod of the end hydraulic cylinder 54 is connected to the groove to drive the gripper finger 40 to move.

[0042] In the above embodiments, the first optical axis 61, the second optical axis 62, the linear bearing, the rack 63, and the gear 64 constitute the support and guiding system of the finger clamp 40; the main end hydraulic cylinder 51, the first tee 52, the second tee 53, the hydraulic pipeline 55, and the slave end hydraulic cylinder 54 constitute the hydraulic drive system of the finger clamp 40; the hydraulic drive system cooperates with the support and guiding system to realize the precise one-dimensional linear motion of the finger clamp 40, as well as the precise centered synchronous opening and closing of the two finger clamps 40.

[0043] According to some embodiments of this application, the inner end of the finger clip 40 is slidably connected to the first optical axis 61 and the second optical axis 62, respectively, and the width of the end of the finger clip 40 is smaller than the width of the inner end of the finger clip 40. In this embodiment, the inner end and the end of the finger clip 40 are located at opposite ends of the extending direction, and the width of the end of the finger clip 40 (fingertip portion) is smaller than the width of the inner end of the finger clip 40 (finger root portion). The fingertip portion is narrower to accommodate fine operation, and the finger root portion is wider to ensure structural strength.

[0044] Furthermore, silicone anti-slip pads are provided on the sides of the two gripping fingers 40 facing each other. The silicone anti-slip pads with high friction are attached to the gripping contact surface to ensure stability during the gripping process.

[0045] Based on the robotic arm system described in this application, its performance was verified through multi-dimensional physical experiments to ensure high reliability and data consistency in complex embodied intelligence tasks. Specifically: First, the physical-level hydraulic decoupling efficiency of the robotic arm system of this application is quantitatively verified to verify its ability to separate "kneading force" and "interaction force" during actual teaching.

[0046] Specifically, a decoupling comparison experiment was conducted between the robotic arm system of this application and the existing robotic arm system Forcemimic (a force-centered robot learning system): the operator held the robotic arm system and performed continuous, high-frequency and large-amplitude clamping actions without contacting any external objects, such as repeatedly opening and closing the clamping of a sponge four times.

[0047] Test results are as follows Figure 5 As shown in the test results, the six components of the six-dimensional force sensor in the robotic arm system of this application consistently maintain an extremely low reference noise level, without any pulse interference or zero-point drift synchronized with the pinching action. In contrast, the existing robotic arm system exhibits significant fluctuations in the six components of the six-dimensional force sensor with each pinch.

[0048] The analysis is as follows: In the robotic arm system of this application, although the main hydraulic cylinder generated severe pressure fluctuations, the hydraulic lines were mechanically anchored at the support assembly via the first tee fitting, and the driving force bypassed the force fulcrum of the six-dimensional force sensor through the bypass frame. Therefore, the six component outputs of the wrist six-dimensional force sensor remained at an extremely low reference noise level, without any pulse interference or zero-point drift synchronized with the pinching action. This result strongly demonstrates that this system completely cuts off the transmission of internal driving force to the sensing path at the physical topology level, ensuring that every mechanical curve subsequently acquired is a pure physical signal generated by environmental interaction, fundamentally eliminating force perception contamination.

[0049] Second, the linearity and dynamic response of the gripping of the robotic arm system of this application are tested in order to analyze the high-fidelity force perception transparency and interaction linearity.

[0050] First, the force transmission characteristics of the master-end input force and slave-end output force were experimentally determined under different gripper opening widths (25mm to 100mm). The test results are as follows: Figure 6 As shown in the test results, under different opening and closing widths, the linear determination coefficients of the input force at the master end and the input force at the slave end are both greater than 0.99 (R0). 2 (>0.99), the input force at the master end and the output force at the slave end exhibit excellent linear correlation.

[0051] Secondly, the experiment also measured the frequency response of the master input and slave output under different loads, and the test results are as follows: Figure 7 As shown in the test results, the phase delay of the hydraulic master-slave system is extremely low within the normal opening and closing frequency range. This ensures a high degree of synchronization between the visual and force modes in the time domain, which is crucial for training imitation learning algorithms with high dynamic response capabilities.

[0052] Third, data quality verification based on the replay process. To verify the validity of the teaching data, this application implements a replay consistency verification process that does not depend on the training strategy. The replay process refers to the system directly reading the collected N sets of sequence data (including precise timestamps, spatial pose coordinates, gripper opening and closing degrees, etc.) and driving the physical robotic arm system to perform open-loop replay in the exact same initial scene. This process does not involve model inference prediction, but rather the physical reconstruction of the original teaching data. The following two aspects are mainly verified: Firstly, spatial accuracy and hand-eye calibration are verified. By comparing the overlap between the trajectory reproduced by the robotic arm system and the original taught trajectory, the positioning accuracy of the visual SLAM algorithm in a specific environment and the accuracy of the coordinate transition matrix can be directly verified. If no collision occurs during the reproduction process and the motion path is precisely aligned, it proves that the spatial fidelity of the pose data meets the standard.

[0053] Secondly, the dynamic closed-loop verification of the interactive force sensing is conducted, which is the most critical verification step in this application. During the reproduction process, the six-dimensional force sensor at the end of the robotic arm system re-records the interactive force signals. The comparison results between the reproduced force signal curve and the force signal curve acquired during teaching are as follows: Figure 8 As shown, by cross-referencing the reproduced force curves with the "pure" force curves recorded during teaching, it can be found that the two have extremely high consistency in peak value, slope, and waveform characteristics. This good fidelity not only proves that the hydraulic decoupling hardware captures the response of the real environment, but also demonstrates that the multimodal combination of visual pose and physical wrist force perception has logical self-consistency, that is, the same motion sequence can stably produce the same force feedback. The high-quality reproduction results indicate that the dataset has eliminated the interference of human error and system noise, and can be used directly as a high-quality expert example for training high-precision robot strategies, significantly improving the robustness and safety performance of embodied intelligence models when deployed in the real world.

[0054] The robotic arm system according to this application has the following significant technical advantages compared to the prior art: (1) This application integrates a six-dimensional force sensor, a hydraulic sensor, an angle encoder, a first camera, and a second camera, realizing multimodal data acquisition and solving the problem of missing force information in the data acquisition of robotic arm operation.

[0055] (2) This application achieves complete physical-level decoupling of drive and perception in the core wrist six-dimensional force perception mode, solving the problems of poor force data quality and physical coupling of driving force / perceived force. Through hydraulic bypass topology design, the driving force generated by kneading is directly guided to the handle frame through L-shaped connector and double three-way fixing mechanism, so that it completely bypasses the force fulcrum of the six-dimensional force sensor; so that the six-dimensional force sensor can only capture environmental feedback, ensuring the purity and signal-to-noise ratio of interactive force data from the source, and providing high-quality underlying support for the model to learn real physical laws.

[0056] (3) Secondly, this application achieves highly transparent bidirectional force feedback of clamping force through a hydraulic transmission system, which significantly improves the naturalness of the teaching operation. Utilizing the incompressibility of the liquid in a quasi-static state, a high-rigidity force transmission loop is formed between the master handle and the slave gripper. The teacher can delicately feel the stiffness change at the moment of contact and the force fluctuation during the continuous clamping process. This tactile feedback not only makes the teaching action more in line with the natural human operating intuition, but also greatly reduces the jitter noise in the trajectory, ensuring a high degree of unity between posture and force mode at the dynamic level.

[0057] (4) This application specifically addresses the blinding issues of existing solutions in terms of robustness and spatial accuracy of visual positioning. Through an innovative dual-camera layout, especially the specially designed "oblique upward" SLAM camera perspective, it can actively capture information about ceilings, lighting fixtures, or building structures with richer textures above the space. This differentiated visual observation strategy greatly enhances the stability of pose tracking in various complex unstructured environments, ensuring the continuity and reliability of spatial coordinate acquisition.

[0058] (5) This application has significant advantages in the precision of mechanical structure design and the user-friendliness of human-machine interaction. This application adopts a triangularly distributed linear bearing constraint system, which provides strong resistance to lateral torque and ensures high repeatability of the gripper during one-dimensional linear opening and closing. The design of constant force spring and rotating mounting column not only realizes the smooth reset of the gripper, but also eliminates the operating resistance caused by the internal torque of the spring. Combined with the physical anchoring of pipeline stress by the L-shaped connector, the whole set of equipment has excellent lightweight portability while ensuring high-performance sensing. This application designs a lightweight portable gripper to get rid of dependence on physical robotic arms and fixed bases, realize efficient and large-scale data acquisition anytime and anywhere, significantly improve the diversity of datasets, realize large-scale and cross-scenario high-quality expert data acquisition, and solve the efficiency and scenario limitations of large-scale and diversified data acquisition.

[0059] In the description of this application, 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 application 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. Therefore, they should not be construed as limitations on this application.

[0060] In the description of this application, "first feature" and "second feature" may include one or more of the features.

[0061] In the description of this application, "multiple" means two or more.

[0062] In the description of this application, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or the first and second features being in contact through another feature between them.

[0063] In the description of this application, the terms "above," "over," and "on top" for the first feature and the second feature include the first feature being directly above or diagonally above the second feature, or simply indicate that the first feature is at a higher horizontal level than the second feature.

[0064] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0065] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A robotic arm system based on the decoupling of force drive and force sensing, characterized in that, include: A support assembly is provided with a main end hydraulic cylinder and a first tee fitting, wherein the main end hydraulic cylinder is connected to the first tee fitting; A gripper base is provided with grippers, two of which are movable and are disposed on the gripper base; the gripper base is also provided with a second three-way connector and two slave hydraulic cylinders, wherein the second three-way connector connects the first three-way connector and the two slave hydraulic cylinders, and the output end of the slave hydraulic cylinder is connected to the corresponding gripper to drive the corresponding gripper to move; A six-dimensional force sensor is connected between the support assembly and the gripper base; A hydraulic sensor, which is connected to the first tee.

2. The robotic arm system based on force-driven and force-sensing decoupling according to claim 1, characterized in that, Both of the gripper fingers are provided with racks, and the gripper base is provided with gears, wherein the gears are meshed with the two racks respectively.

3. The robotic arm system based on force-driven and force-sensing decoupling according to claim 2, characterized in that, Also includes: An angle encoder is connected to the gear to detect the rotation angle of the gear.

4. The robotic arm system based on force-driven and force-sensing decoupling according to claim 1, characterized in that, The gripper base is also provided with two spring assemblies, which are connected to the corresponding gripper fingers to drive the corresponding gripper fingers to reset.

5. The robotic arm system based on force-driven and force-sensing decoupling according to claim 4, characterized in that, The spring assembly includes: Mounting column, which is rotatably connected to the gripper base; A constant force spring is wound around the mounting post, and the outer end of the constant force spring is connected to the corresponding clamping finger.

6. The robotic arm system based on force-driven and force-sensing decoupling according to claim 1, characterized in that, Also includes: A first camera and a second camera are respectively disposed on the gripper base, wherein the detection end of the first camera is positioned directly opposite the working area of ​​the gripper finger, and the detection end of the second camera is positioned facing the non-working area of ​​the gripper finger.

7. The robotic arm system based on force-driven and force-sensing decoupling according to claim 6, characterized in that, The first camera is configured as a depth camera, and the second camera is configured as a SLAM camera.

8. The robotic arm system based on force-driven and force-sensing decoupling according to claim 1, characterized in that, The gripper base is provided with two first optical axes and two second optical axes, wherein the gripper fingers connect the corresponding first optical axis and the two second optical axes.

9. The robotic arm system based on force-driven and force-sensing decoupling according to claim 8, characterized in that, The inner end of the clamping finger is slidably connected to the first optical axis and the second optical axis respectively, and the width of the end of the clamping finger is smaller than the width of the inner end of the clamping finger.

10. The robotic arm system based on force-driven and force-sensing decoupling according to claim 8, characterized in that, The clip finger is provided with three connecting holes, which are used to connect to the corresponding first optical axis or second optical axis; wherein, the three connecting holes are located at the three vertices of the triangle.

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