Mechanical arm and protective sleeve shell thereof

Abstract

The utility model relates to a mechanical arm and a protective sleeve shell thereof. The mechanical arm and the protective sleeve shell thereof mainly comprise a four-joint mechanical arm, a first joint sleeve shell, a second joint sleeve shell, a third joint sleeve shell and a fourth joint sleeve shell. Each sleeve shell comprises an outer-layer plastic shell, a layer of flexible electrode is arranged in the plastic shell, an insulating soft cushion is arranged on the inner side of the flexible electrode, a shielding layer is arranged on the inner side of the insulating soft cushion, and an insulating layer is arranged on the inner side of the shielding layer. The flexible electrode is connected into a control panel through a lead, and the control panel is arranged at the head of the joint. The control panel is connected with a power supply and a communication cable from the mechanical arm, communication adopts a bus mode, and the control panel and the communication cable of the mechanical arm share a bus. The electrodes in the protective sleeve shell form a group of mutual capacitance in pairs, when the human body is about to collide with the mechanical arm, the direction of the human body is detected in advance, a signal is provided for the mechanical arm, and collision between the mechanical arm and the human body is avoided.

Description

Technical Field

[0001] The utility model relates to an anti-collision technology for a mechanical arm, in particular to a protective cover shell of a joint mechanical arm capable of detecting proximity. Background Art

[0002] A robotic arm is a complex system with high precision, high nonlinearity and strong coupling. It has been widely used in the industrial field due to its flexible operation. In the operation of a robotic arm, operator safety has always been a concern. How to avoid accidental collision between the robotic arm and the human body, or avoid collision between the robotic arm and external objects, is of great significance to the operation of the robotic arm.

[0003] For anti-collision detection of robotic arms, capacitive detection technology is favored due to its advantages in ease of layout, structure, and cost.

[0004] In the anti-collision detection of the capacitor as a robotic arm, the current practice is to use a flexible electrode as the electronic skin that wraps the robotic arm, such as CN114608626A, CN216748116U, etc., which publicly set the electronic skin with flexible electrodes, and use the electrode's induction of external dielectrics to achieve proximity. The reason why the electrode requires flexibility is to be able to adapt to packages of different shapes. Due to the strength requirements of the robotic arm, the outer shell of the robotic arm itself is made of metal, and the flexible electrode cannot be directly attached to the metal shell. A flexible insulating substrate such as FPC is required as isolation on the one hand and as a carrier of the flexible electrode on the other hand. When in use, the flexible electrode is arranged on the flexible substrate and then wrapped to the outer surface of the robotic arm by gluing. There are two problems: first, the electrode soft package has a structural instability problem, which seriously affects the high-sensitivity detection requirements of the electrode. At the same time, the arrangement of the electrodes of each robotic arm is not uniform, and the product consistency is poor. Second, the articulated robotic arm rotates in different axial directions through multiple joints, and the end effector of the robotic arm can move to any position within a certain spatial range, while the power supply lines and signal detection lines of the outer surface electrodes become entangled during the rotation of the robotic arm. Utility Model Content

[0005] The utility model provides a mechanical arm protective cover structure to improve the deficiencies of the prior art.

[0006] To this end, a robot arm protective shell is provided, which is configured as a non-conductive rigid shell, and the non-conductive rigid shell includes at least one segment; each segment includes at least two shells, and each shell is mounted on the outside of the robot arm by splicing; a detection electrode for sensing the approach of an external object is arranged on at least one or all of the segments, and the relative position of the detection electrode and the segment in which it is located is fixed; each segment is provided with at least one first area for wrapping a rotating joint of the robot arm, and the segment with the electrode is provided with a circuit board and wires, and the circuit board draws electricity and / or communicates from the corresponding rotating joint of the robot arm through the wires, and the wires are at least partially located in the first area and arranged along the rotating axis of the rotating joint of the robot arm; the circuit board includes at least a capacitance-to-digital conversion circuit, and the capacitance-to-digital conversion circuit is coupled to each detection electrode on the corresponding segment.

[0007] Compared with the existing flexible electrode electronic skin technology, the advantages of this utility model are:

[0008] (1) By arranging the electrode in a non-conductive rigid shell and then sleeved on the outside of the robot arm, the electrode is rigid, the robot arm is not easily deformed during operation, the structure is stable, and the shell protects the robot arm;

[0009] (2) the circuit board obtains power and / or communication from the corresponding mechanical arm rotation joint through wires, and the wires are at least partially located in the first area and arranged along the rotation axis of the mechanical arm rotation joint to prevent the wires from being entangled during the mechanical arm rotation around the joint;

[0010] (3) Capacitance-to-digital conversion circuits (CDCs), such as DAI7142 and ADI7147, use a Δ-Σ modulation method to directly convert the measured capacitance value into a digital value by repeatedly charging and discharging the measured capacitance and comparing it with a reference capacitance (see: US Patent Number: 5,134,401), thereby increasing the capacitance measurement sensitivity to 1ff level, meeting the capacitance measurement sensitivity requirements of the measurement system, and having the characteristic of being immune to stray capacitance. In particular, the design of these chips has multiple channels, making the circuit design simple and convenient, thereby effectively reducing costs and installation difficulty.

[0011] As an improvement solution, the circuit board is provided with a processing module, and the processing module is coupled with a corresponding capacitance digital conversion circuit to realize independent data processing of each electrode segment to form a distributed arrangement architecture.

[0012] In the utility model, the circuit board can be located at the arm of the segment or other positions. As another improvement scheme, it is preferred to arrange the circuit board on the rotation axis of the corresponding mechanical arm rotation joint on the first area, so that the wire arrangement path is the shortest, reduce the line twisting situation, and provide a good foundation for small signal capacitance perception. Furthermore, the electronic device is arranged on the outward side of the circuit board for easy installation and maintenance. The middle part of the circuit board has a hole, and the wires are perforated along the rotation axis of the corresponding mechanical arm rotation joint to obtain power and / or communication. Furthermore, the circuit board is circular, the electronic devices are distributed around the hole, and the circuit board is convenient for wiring; and / or, the first area is a cylindrical structure, and the circuit board is located on the cylindrical end face, so as to simplify the structure and line layout. Furthermore, the electrode extends on the shell of the segment where it is located to be adjacent to the corresponding circuit board, reducing the parasitic capacitance effect caused by the analog signal transmission path, while improving stability.

[0013] In the present invention, the electrode can be glued and fixed to the corresponding segment, but as another improvement scheme, it is preferred to arrange the electrode to be fixed to the corresponding segment by sputtering or coating. By sputtering or coating, especially sputtering, the firmness of the electrode fixed to the casing can be further enhanced, the product consistency can be improved, and the overall thickness of the casing with the electrode can be reduced. In another scheme, the electrode is wrapped inside the corresponding segment by in-mold injection molding, which also achieves enhanced firmness. In the present invention, the outer diameter of the protective casing is 1 cm larger than the robot arm, 5 mm on one side, and 2.5 mm thick. The upper and lower halves are fixed by screws. After the casing is put on the robot arm, the volume of the robot arm is not significantly increased, and it will not interfere with the operation requirements of the robot arm.

[0014] As another improvement, the electrode can be arranged on the inner surface or outer surface of the segment shell. The inner surface is the preferred solution, in which case the shell also protects the electrode and reduces the possibility of electrode displacement. Furthermore, the segment with the electrode is provided with a positioning groove for fixing the electrode, and the positioning groove further constrains the electrode position, while improving product consistency.

[0015] As another improvement scheme, the non-conductive rigid shell is made of carbon fiber or plastic, wherein carbon fiber can take into account both lightness and hardness, thereby achieving weight reduction while ensuring protective performance and reducing the load on the robotic arm.

[0016] In the present utility model, the number of electrodes on the segment can be one, in which case the CDC samples the self-capacitance of the electrode for proximity perception. As another improvement scheme, the number of electrodes on the corresponding segment is set to at least two, and the CDC can use the self-capacitance of the electrode and / or the mutual capacitance of the electrode for proximity perception. Self-capacitance detection has a large distance and is directional. The advantage of mutual capacitance is that it is less affected by environmental changes. The different characteristics of the two are used to achieve a comprehensive judgment or a biased selection based on demand conditions. Furthermore, the number of electrodes on the corresponding segment is set to at least three to form an arrangement around the robot arm, so as to achieve a 360° detection capability around the robot arm. Specifically, electrodes divided into four areas in one circle can be set.

[0017] As another improvement, a shielding layer is provided between the electrode on each segment of the non-conductive rigid shell and the robotic arm to isolate interference of the robotic arm on electrode detection.

[0018] As another improvement, the circuit board is provided with a wireless communication device such as Bluetooth for wireless communication between each other. In the initial stage of starting the robot arm, Bluetooth is configured, and each circuit board is initialized through Bluetooth communication. In the utility model, a hole is opened at the shoulder shield (i.e., joint shield) of the robot arm for passing the power line and CAN communication line, and the circuit board obtains power and CAN communication from the robot arm.

[0019] A mechanical arm is also provided, comprising the mechanical arm protective cover shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The main structural diagram of the mechanical arm and its protective cover is shown;

[0021] Figure 2 The main structural diagram of the protective casing is shown;

[0022] Figure 3 A schematic diagram of the inner and outer layers of the protective shell is shown;

[0023] Figure 4 A schematic diagram showing the distribution of electrodes of the protective shell joint 1 is shown;

[0024] Figure 5 A schematic diagram showing the distribution of electrodes of the second joint of the protective sleeve shell is shown;

[0025] Figure 6 A schematic diagram showing the distribution of electrodes at joints three and four of the protective shell is shown;

[0026] Figure 7 A schematic diagram showing the layout of the protective shell capacitance detection and signal processing circuit board is shown;

[0027] Figure 8A schematic diagram of the arrangement of electrodes on the protective cover of the protective casing circuit board is shown. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0029] like Figure 1 As shown, the robot arm and its protective cover mainly include five parts: a robot arm body 50, a first joint protective cover 10, a second joint protective cover 20, a third joint protective cover 30, and a fourth joint protective cover 40. Multiple electrodes are arranged in the four joint protective covers to form multiple capacitors, which can perform anti-collision detection in different directions.

[0030] like Figure 2 As shown, each joint protection shell 600 is composed of four parts, namely a joint protection upper shell 601, a joint protection lower shell 602, a capacitance detection and signal processing circuit board 603, and a circuit board protection shell 604.

[0031] like Figure 3 As shown, the upper and lower joint protection shells 700 are respectively a rigid plastic shell 701, a conductive electrode 702, a shielding layer 703, and an insulating isolation bubble surface 704 from the outside to the inside. The conductive electrode 702 is wrapped inside the plastic shell 701 by in-mold injection molding, and an exposed point is reserved at the peripheral position of the circuit board installation, and is electrically connected to the circuit board 603 through the spring on the circuit board 603; the shielding layer 703 is plated on the surface of the plastic shell 701 facing the robot arm by electroplating, and a connection point is reserved at the peripheral position of the circuit board 603 installation, and is electrically connected to the circuit board 603 through the spring on the circuit board 603.

[0032] like Figure 4 As shown, 14 conductive electrodes are arranged inside the upper shell 101 of the first joint protection cover, which are 1011, 1012, ... 1024, among which 1011, 1012 ... 1017 are connected to the circuit board 6031, and 1018, 1019 ... 1024 are connected to the circuit board 6032. Similarly, 14 conductive electrodes are arranged inside the lower shell 102 of the first joint protection cover, which are connected to the circuit boards 6031 and 6032 respectively. The shielding electrodes 7041 and 7042 of the upper shell 101 and the lower shell 102 of the first joint protection cover are simultaneously connected to the signal grounds of the circuit boards 6031 and 6032.

[0033] like Figure 5As shown, seven conductive electrodes, namely 2011, 2012, ... 2017, are arranged inside the upper shell 201 of the second joint protection cover, and these seven electrodes are connected to the circuit board 6033; similarly, seven conductive electrodes are arranged inside the lower shell 202 of the second joint protection cover, and are connected to the circuit board 6033; the shielding electrodes 7043 and 7044 of the upper shell 201 and the lower shell 202 of the second joint protection cover are simultaneously connected to the signal ground of the circuit board 6033.

[0034] like Figure 6 As shown, inside the upper shell 301 of the third joint protection cover, 7 conductive electrodes are arranged, namely 3011, 3012, and 3013, and these 3 electrodes are connected to the circuit board 6034; similarly, inside the lower shell 302 of the third joint protection cover, 3 conductive electrodes are also arranged, which are connected to the circuit board 6034; the shielding electrodes 7045 and 7046 of the upper shell 301 and the lower shell 302 of the third joint protection cover are simultaneously connected to the signal ground of the circuit board 6034. The fourth joint protection cover is exactly the same as the third joint protection cover.

[0035] like Figure 7 As shown, the capacitance detection and signal processing circuit board 603 mainly includes an MCU chip 6301, a power supply and CAN communication terminal 6302, and 16 conductive springs 6303, 6304, ... 63018. These 16 springs are responsible for contacting the detection electrodes and shielding on the protective shell for electrical connection. The power supply and CAN communication terminal 6302 is connected to the power supply of the robot arm and the CAN bus through a cable. The MCU chip 6301 mainly processes the capacitance signal and filters these capacitance data.

[0036] like Figure 8 As shown, two electrodes 6401 and 6402 are arranged inside the circuit board protective shell 604, which are electrically connected to the circuit board 603 through spring pins 6403 and 6404. The two electrodes form a group of mutual capacitance, which can detect obstacle signals from the direction of the circuit board protective shell.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit the protection scope of the utility model. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the utility model.

Claims

1. A protective cover for a robotic arm, characterized in that: The robot arm protective shell is configured as a non-conductive rigid shell, and the non-conductive rigid shell includes at least one segment; Each segment includes at least two shells, and each shell is sleeved on the outside of the robot arm by splicing; A detection electrode for sensing the approach of an external object is arranged on at least one or all of the segments, and the relative position of the detection electrode and the segment where it is located is fixed; Each segment is provided with at least one first area for wrapping the rotating joint of the robot arm, and the segment provided with electrodes is provided with a circuit board and a wire, and the circuit board obtains electricity and / or communicates from the corresponding rotating joint of the robot arm through the wire, and the wire is at least partially located in the first area and arranged along the rotating axis of the rotating joint of the robot arm; The circuit board at least includes a capacitance-to-digital conversion circuit, and the capacitance-to-digital conversion circuit is coupled to each detection electrode on the corresponding segment.

2. The mechanical arm protective cover according to claim 1, characterized in that: The circuit board is provided with a processing module, and the processing module is coupled to the corresponding capacitance digital conversion circuit.

3. The mechanical arm protective cover according to claim 1, characterized in that: The circuit board is located on the rotation axis of the corresponding mechanical arm rotation joint on the first area.

4. The mechanical arm protective cover according to claim 3, characterized in that: The electronic device is arranged on the outward side of the circuit board, a hole is opened in the middle of the circuit board, and the wire passes through the hole to obtain power and / or communication along the rotation axis of the corresponding mechanical arm rotation joint.

5. The mechanical arm protective cover according to claim 3 or 4, characterized in that: The circuit board is circular; and / or The first area is a cylindrical structure, and the circuit board is located on the cylindrical end surface.

6. The mechanical arm protective cover according to claim 3, characterized in that: The electrodes extend on the shell of the segment where the electrodes are located to be adjacent to the corresponding circuit board.

7. The mechanical arm protective cover according to claim 1, characterized in that: The electrodes are fixed to the corresponding segments by sputtering or coating; or the electrodes are wrapped inside the corresponding segments by in-mold injection molding.

8. The mechanical arm protective cover according to claim 1, characterized in that: The electrode is arranged on the inner surface or the outer surface of the shell.

9. The mechanical arm protective cover according to claim 8, characterized in that: The segment provided with the electrode is provided with a positioning groove for fixing the electrode.

10. The mechanical arm protective cover according to claim 1, characterized in that: The non-conductive rigid shell is made of carbon fiber or plastic.

11. The mechanical arm protective cover according to claim 1, characterized in that: The number of electrodes on the corresponding segment is set to be at least two.

12. The robot arm protective cover according to claim 11, characterized in that: The number of electrodes on the corresponding segment is at least three and is arranged around the circumference of the robot arm.

13. The robot arm protective cover according to claim 1, characterized in that: The circuit boards are provided with wireless communication devices for wireless communication between each other.

14. A robotic arm, characterized in that: It comprises a mechanical arm protective cover shell as described in any one of claims 1-13.

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