Self-adaptive force feedback control device for end effector of industrial robot

Abstract

The utility model relates to a self-adaptive force feedback control device of an industrial robot end effector, which comprises a mechanical arm and a clamping jaw arranged at the tail end of the mechanical arm, the clamping jaw comprises a first joint and a second joint, one end of the first joint is hinged with the tail end of the mechanical arm, the other end of the first joint is hinged with one end of the second joint, and the other end of the second joint is hinged with the mechanical arm. One end of a hydraulic rod is hinged to the tail end of the mechanical arm, the other end of the hydraulic rod is hinged to the middle section of a first joint, the first joint is hollow, an electric push rod is arranged in the first joint, one end of the electric push rod is hinged to a second joint, and the other end of the electric push rod is fixedly installed in the first joint through a sliding block. A baffle is fixedly installed in the end, away from the second joint, of the first joint, a pressure sensor is arranged on the side, close to the sliding block, of the baffle, and the pressure sensor is arranged at a relatively fixed position, so that the pressure detection value is more stable and accurate.

Description

Technical Field

[0001] This utility model relates to the field of robotics technology, and in particular to an adaptive force feedback control device for an end effector of an industrial robot. Background Technology

[0002] In modern industrial production, industrial robots play an increasingly important role. As the part that directly contacts the object being operated, the performance of their end effectors directly affects production efficiency and product quality.

[0003] Traditional industrial robot end effectors, when gripping items, lack an effective force feedback mechanism. The robot cannot perceive the magnitude of the force applied by the gripper to the item in real time, potentially leading to insecure gripping during operation. This can cause items to slip during handling or processing, disrupting production continuity and even damaging products, resulting in economic losses. Furthermore, excessive gripping force can easily damage the gripped items, especially delicate or fragile items, potentially rendering them unusable and increasing production costs. In addition, traditional end effectors typically have a gripper consisting of a first and second joint. Pressure sensors are placed at the ends of the hydraulic rod at the end of the robotic arm, at the ends of the first joint, and at the connection point between the second and third joints. Due to frequent hinge movements at these locations, the detected values ​​are highly unstable, making it difficult to provide accurate and reliable force feedback. Placing pressure sensors directly on the second joint requires strict control of the contact position when gripping the item, undoubtedly increasing the complexity and difficulty of the control system and placing higher demands on the robot's operational precision and control algorithms.

[0004] The existing technical solutions have the following drawbacks: setting the force feedback at the end of the gripper results in inaccurate pressure values ​​because different items require different gripping positions, and the control requirements are relatively high. Utility Model Content

[0005] The purpose of this invention is to provide an adaptive force feedback control device for an industrial robot end effector to solve the problems existing in the prior art.

[0006] The above-mentioned technical objective of this utility model is achieved through the following technical solution:

[0007] An adaptive force feedback control device for an industrial robot end effector includes a robotic arm and a gripper disposed at the end of the robotic arm. The gripper includes a first joint and a second joint. One end of the first joint is hinged to the end of the robotic arm, and the other end of the first joint is hinged to one end of the second joint. One end of a hydraulic rod is hinged to the end of the robotic arm, and the other end of the hydraulic rod is hinged to the middle section of the first joint. The first joint is hollow inside, and an electric push rod is disposed inside the first joint. One end of the electric push rod is hinged to the second joint, and the other end of the electric push rod is fixedly mounted inside the first joint via a slider. The slider is slidably mounted inside the first joint. A baffle is fixedly installed inside the first joint at the end away from the second joint, where the electric push rod and the slider are hinged and fixed. A pressure sensor is disposed on the side of the baffle near the slider for detecting the force applied to the baffle by the slider.

[0008] By adopting the above technical solution, multiple grippers need to be evenly arranged axially at the end of the robotic arm during use. In actual use, the object is gripped by the second joints on these grippers. Therefore, detecting the force on the second gripper allows for judgment of the gripping stability. If the force on the second gripper is less than a set value, the gripping is not secure; if it is much greater than the set value, it may damage the object. In this solution, the hydraulic rod can adjust the angle of the first joint, and the electric push rod can adjust the angle at the hinge between the second and first joints. Because both ends of the hydraulic rod, both ends of the first joint, and the connecting end of the second joint are all hinged, if pressure sensors are placed at these locations, the detected values ​​will be unstable. If a pressure sensor is directly placed on the second joint, the contact position of the second joint gripping the object needs to be controlled to increase... With added control requirements, a pressure sensor is placed at the end of the electric actuator located inside the first joint to detect the most stable position. Specifically, there are three nodes: the node where the electric actuator is installed inside the first joint, the node where the electric actuator is hinged to the second joint, and the node where the second joint is hinged to the first joint. These three nodes form a triangular structure. Therefore, when the node where the electric actuator is fixedly installed inside the first joint and the node where the second joint is hinged to the first joint are fixed points and fixed sides (because when it is necessary to grasp an object, the electric actuator extends, and the node where the electric actuator is located inside the first joint is blocked by the baffle and cannot move backward, so this point is relatively fixed), during the extension and retraction of the electric actuator, the position of the other node will change, thereby adjusting the position of the second joint and realizing the gripping of the object through the cooperation of multiple second joints.

[0009] In a further embodiment, the end of the second joint that is not connected to the first joint is provided with a movable block, and the movable block is connected to the second joint through a steering tie rod ball joint.

[0010] By adopting the above technical solution, when the second joint needs to cooperate with each other to clamp the object, the movable block contacts the object first. Because it is fixed by the ball head of the steering tie rod, the angle of the movable block can change with the surface of the object, fit the surface of the object more closely, and thus make the clamping force more stable.

[0011] In a further embodiment, a limiting plate is provided inside the first joint near one end of the second joint. The limiting plate is used to restrict the sliding position of the slider, and the baffle and the limiting plate are used to limit the sliding distance of the slider to 0.1-0.2mm.

[0012] In a further embodiment, a rubber gasket is provided between the limiting plate and the slider.

[0013] In a further embodiment, the hydraulic rod is a miniature hydraulic rod.

[0014] By adopting the above technical solutions, the miniature hydraulic rod is generally a complete structure with its own oil pump and oil tank, without the need for any external structures, which facilitates actual control and use. In a better option, it can be replaced with an electric rod, which is even easier to control.

[0015] In a further embodiment, a ranging sensor is provided on the second joint.

[0016] In summary, this utility model has the following beneficial effects:

[0017] 1. During use, multiple grippers are axially evenly positioned at the end of the robotic arm. In actual use, items are clamped via the second joints on these grippers. Therefore, detecting the force on the second grippers allows for assessment of the gripping strength. If the force is less than a set value, the gripping is weak; if it is significantly greater, damage to the item may occur. In this design, the hydraulic rod adjusts the angle of the first joint, and the electric push rod adjusts the angle at the hinge between the second and first joints. Because both ends of the hydraulic rod, both ends of the first joint, and the connection point between the second and second joints are hinged, pressure sensors at these locations would produce unstable readings. Directly installing pressure sensors on the second joint requires controlling the contact position of the gripper, increasing control complexity. Therefore, placing a pressure sensor at the end of the electric actuator located inside the first joint is the most stable detection position. Specifically, there are three nodes: the node where the electric actuator is installed inside the first joint, the node where the electric actuator is hinged to the second joint, and the node where the second joint is hinged to the first joint. These three nodes form a triangular structure. So, when the node where the electric actuator is fixedly installed inside the first joint and the node where the second joint is hinged to the first joint are fixed points and fixed sides (because when it is necessary to grasp an object, the electric actuator extends, and the node where the electric actuator is located inside the first joint is blocked by the baffle and cannot move backward, so this point is relatively fixed), during the extension and retraction of the electric actuator, the position of the other node will change, thereby adjusting the position of the second joint and realizing the effect of grasping the object through the cooperation of multiple second joints. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0019] Figure 2 This is a schematic diagram of the internal structure of the first joint used to illustrate this utility model.

[0020] In the diagram, 1 is the gripper; 2 is the first joint; 3 is the second joint; 4 is the hydraulic rod; 5 is the electric push rod; 6 is the slider; and 7 is the baffle. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to the accompanying drawings.

[0022] Identical parts are indicated by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to the attached figures. Figure 1In this specification, the terms "bottom surface" and "top surface," "inner" and "outer" refer to the direction toward or away from the geometry of a specific component. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this specification, "a plurality of" means two or more, unless otherwise explicitly and specifically defined by the direction of the center.

[0023] Example 1:

[0024] like Figures 1-2 As shown, an adaptive force feedback control device for an industrial robot end effector includes a robotic arm and a gripper 1 disposed at the end of the robotic arm. The gripper 1 includes a first joint 2 and a second joint 3. One end of the first joint 2 is hinged to the end of the robotic arm, and the other end of the first joint is hinged to one end of the second joint 3. One end of a hydraulic rod 4 is hinged to the end of the robotic arm, and the other end of the hydraulic rod 4 is hinged to the middle section of the first joint 2. The first joint 2 is hollow inside, and an electric push rod 5 is disposed inside the first joint 2. One end of the electric push rod 5 is hinged to the second joint 3, and the other end of the electric push rod 5 is fixedly installed inside the first joint 2 by a slider 6. The slider 6 is slidably installed inside the first joint 2, and the electric push rod 5 is hinged to the slider 6. A baffle 7 is fixedly installed inside the end of the first joint 2 away from the second joint. A pressure sensor is provided on the side of the baffle 7 near the slider 6 to detect the force applied by the slider 6 to the baffle 7. A movable block is provided at the end of the second joint 3 that is not connected to the first joint. The movable block is connected to the second joint 3 through a steering tie rod ball joint. A limit plate is provided inside the first joint 2 near the end of the second joint 3. The limit plate is used to limit the sliding position of the slider 6. The baffle 7 and the limit plate are used to limit the sliding distance of the slider 6 to 0.1-0.2mm. A rubber gasket is provided between the limit plate and the slider 6. The hydraulic rod 4 is a miniature hydraulic rod 4. A distance sensor is provided on the second joint 3. The distance sensor is used to assist in determining whether the gripper is holding the object.

[0025] Specific implementation process: During use, multiple grippers need to be evenly arranged axially at the end of the robotic arm. In actual use, the item is gripped by the second joints on these grippers. Therefore, detecting the force on the second gripper allows for judgment of the gripping stability. If the force on the second gripper is less than a set value, the gripping is not secure; if it is significantly greater than the set value, it may damage the item. In this solution, the hydraulic rod can adjust the angle of the first joint, and the electric push rod can adjust the angle at the hinge point between the second and first joints. Because both ends of the hydraulic rod, both ends of the first joint, and the connection point of the second joint are all hinged, pressure sensors placed at these locations will produce unstable readings. If a pressure sensor is directly placed on the second joint, the contact position of the second joint gripping the item needs to be controlled, increasing the control complexity. Therefore, a pressure sensor is installed at the end of the electric actuator located inside the first joint to detect the most stable position. Specifically, there are three nodes: the node where the electric actuator is installed inside the first joint, the node where the electric actuator is hinged to the second joint, and the node where the second joint is hinged to the first joint. These three nodes form a triangular structure. So, when the node where the electric actuator is fixedly installed inside the first joint and the node where the second joint is hinged to the first joint are fixed points and fixed sides (because when it is necessary to grasp an object, the electric actuator extends, and the node where the electric actuator is located inside the first joint is blocked by the baffle and cannot move backward, so this point is relatively fixed), during the extension and retraction of the electric actuator, the position of the other node will change, thereby adjusting the position of the second joint and realizing the effect of grasping the object through the cooperation of multiple second joints.

[0026] In the embodiments disclosed in this utility model, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments disclosed in this utility model according to the specific circumstances.

[0027] This specific embodiment is merely an explanation of the present utility model and is not intended to limit the present utility model. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present utility model, they are protected by patent law.

Claims

1. An adaptive force feedback control device for an industrial robot end effector, characterized by: The device includes a robotic arm and a gripper (1) located at the end of the robotic arm. The gripper (1) includes a first joint (2) and a second joint (3). One end of the first joint (2) is hinged to the end of the robotic arm, and the other end of the first joint is hinged to one end of the second joint (3). One end of a hydraulic rod (4) is hinged to the end of the robotic arm, and the other end of the hydraulic rod (4) is hinged to the middle section of the first joint (2). The first joint (2) is hollow inside, and an electric push rod (5) is installed inside the first joint (2). One end of the electric push rod (5) is hinged to the second joint (3), and the other end of the electric push rod (5) is fixedly installed inside the first joint (2) by a slider (6). The slider (6) is slidably installed inside the first joint (2). A baffle (7) is fixedly installed inside the end of the first joint (2) away from the second joint, which is hinged to the electric push rod (5) and the slider (6). A pressure sensor is provided on the side of the baffle (7) near the slider (6) to detect the force applied by the slider (6) to the baffle (7).

2. The adaptive force feedback control device for an industrial robot end effector according to claim 1, wherein: The second joint (3) is provided with a movable block at the end that is not connected to the first joint, and the movable block is connected to the second joint (3) through the ball head of the steering tie rod.

3. The adaptive force feedback control device for an industrial robot end effector according to claim 1, characterized in that: A limiting plate is provided inside the first joint (2) at one end near the second joint (3). The limiting plate is used to restrict the sliding position of the slider (6). The baffle (7) and the limiting plate are used to limit the sliding distance of the slider (6) to 0.1-0.2mm.

4. The adaptive force feedback control device for an industrial robot end effector according to claim 3, characterized in that: A rubber gasket is provided between the limiting plate and the slider (6).

5. The adaptive force feedback control device for an industrial robot end effector according to claim 1, characterized in that: The hydraulic rod (4) is a miniature hydraulic rod (4).

6. The adaptive force feedback control device for an industrial robot end effector according to claim 1, characterized in that: A distance sensor is provided on the second joint (3).

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