Intelligent mechanical arm wrist force sensor

Abstract

The utility model provides an intelligent mechanical arm wrist force sensor, and relates to the technical field of intelligent robots, the intelligent mechanical arm wrist force sensor comprises a mechanical arm mounting seat, the top of the mechanical arm mounting seat is provided with a detection processing circuit through a nut, and the top of the mechanical arm mounting seat is provided with an anti-overload force measuring elastic body; a protective shell is arranged at the top of the anti-overload force-measuring elastic body; the anti-overload force measurement elastic body comprises an inner shell and an outer shell, an outer rigid connector is arranged at the top of the outer shell, a high-precision measurement loop is arranged in the detection processing circuit, and the measurement requirements of force and torque in three orthogonal directions of the wrist joint sensor are met. The designed assembly type mechanical arm mounting base can be matched with the tail ends of joints of most robots in the market, the measurement requirements of most collaborative robots and humanoid robots are met, and the mechanical arm has the advantages of being capable of recognizing spatial multi-dimensional force, high in measurement precision, high in overload resistance, easy and convenient to install and rapid to operate.

Description

Technical Field

[0001] The utility model relates to the technical field of intelligent robots, in particular to an intelligent mechanical arm wrist force sensor. Background Art

[0002] With the advancement of technology and the powerful breakthrough of artificial intelligence, the wave of intelligent robots has swept the world. Intelligent robots attach great importance to perception capabilities, and force sensors (especially six-dimensional force sensors) have attracted much attention in the industry.

[0003] According to the measurement dimension, force sensors can be divided into one to six-dimensional force sensors. The number of dimensions they can measure is the number of dimensional force sensors. The most common ones are one-dimensional, three-dimensional and six-dimensional force sensors, while two-dimensional and five-dimensional force sensors are relatively rare. The existing wrist force sensors generally have a relatively simple structure, large size, poor adaptability, insufficient overload resistance, etc. For example, the Chinese patent number is CN114474160A, "A serial redundant robot wrist force sensor and its use method", which includes a first strain sensing body and a second strain sensing body with the same range; both include: a rigid boundary ring, a rigid boundary block and at least three strain beams; strain sensitive elements are arranged on the strain beam, and each strain sensitive element on the two strain sensing bodies is connected to the Wheatstone bridge in the same way. However, its public information lacks the adaptive design of the intelligent robot terminal and the logic processing design of the variable measurement environment. There is also a lack of practical content in the hardware structure decoupling and small integration, which makes it difficult to meet the complex application conditions and high-precision measurement requirements of intelligent robots.

[0004] Therefore, the development of a robotic arm wrist joint sensor with high reliability, high sensitivity, high precision and high adaptability has a broad application market. The multi-dimensional force wrist joint sensor adopts an assembled integrated design, which has the characteristics of multi-dimensional force adaptability measurement, high precision, strong overload resistance, easy installation and quick operation, and can solve the above-mentioned problems. Utility Model Content

[0005] The purpose of the utility model is to provide an intelligent robotic arm wrist joint sensor to solve the problems proposed in the above background technology that the structure is relatively simple, the size is large, the adaptability is not strong, the overload resistance is insufficient, and it is difficult to meet the measurement needs of intelligent robots.

[0006] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme: an intelligent mechanical arm wrist force sensor, comprising: a mechanical arm mounting seat, a detection processing circuit is installed on the top of the mechanical arm mounting seat through a nut, an anti-overload force measuring elastic body is arranged on the top of the mechanical arm mounting seat, and a protective shell is arranged on the top of the anti-overload force measuring elastic body;

[0007] The anti-overload force measuring elastomer includes an inner shell and an outer shell, the top of the outer shell is provided with an external rigid connector, the top of the inner shell is provided with an internal rigid connector, the outer wall of the inner shell is provided with three anti-overload limiting auxiliary mechanisms, the outer wall of the inner shell is provided with three rectangular strain beams, and the tops of the three anti-overload limiting auxiliary mechanisms are fixedly installed with end tool connection interfaces.

[0008] Preferably, the detection and processing circuit is provided with an integrated microprocessor MCU logic unit, and the detection and processing circuit can realize single-dimensional force measurement and multi-dimensional force measurement functions through the integrated microprocessor MCU logic unit, and can also be converted into other coordinate system measurement methods such as cylindrical coordinates, such as force or torque measurement in six directions of Cartesian coordinate systems XYZ and Mx, My, Mz, and the signal output form includes analog signal output or digital signal output forms such as RS / RS / CAN.

[0009] Preferably, the robot arm mounting base and the anti-overload force measuring elastomer are installed through flange connection, which makes the device easy to replace. At the same time, the end tool connection interface can be adapted and processed according to the size of the user's tool end, so it can match the vast majority of robot joint end interfaces on the market and meet the measurement needs of most collaborative robots and humanoid robots.

[0010] Preferably, the outer walls of the three rectangular strain beams are respectively provided with eight self-compensating strain gauges. The anti-overload force measuring elastomer can effectively offset the accidental force loads under harsh working conditions such as collision and vibration when the robotic arm is running, while meeting the requirements of mechanical measurement, thereby ensuring the reliability of the sensor and extending its service life. The self-compensating strain gauge and the detection processing circuit are jointly designed and installed nearby, which can meet the weak signal analysis and processing capabilities of the intelligent robot in a complex electromagnetic environment, ensure product measurement accuracy, and improve test response speed.

[0011] Preferably, the three rectangular strain beams and the three anti-overload limit auxiliary mechanisms are evenly distributed between the outer rigid connector and the inner rigid connector, and the three rectangular strain beams adopt a rectangular symmetrical structure, the interior of the three rectangular strain beams is hollow, a weak coupling structural beam is arranged on one side of the outer wall of the three rectangular strain beams, and the inner surface walls of the three weak coupling structural beams are fixedly mounted on the inner surface wall of the outer shell, an overload protection interval is arranged between one side of the outer wall of the three anti-overload limit auxiliary mechanisms and the inner surface wall of the outer shell, and the end tool connection interface is arranged on the force transmission path of the anti-overload limit auxiliary mechanism. The overload protection function of the multi-dimensional force sensor is realized by opening and closing the effective overload protection interval, ensuring the measurement performance of the sensor under harsh working conditions such as collision and vibration, and improving the life of the sensor. At the same time, the hollow interior of the beam is conducive to enhancing the stress and strain test performance and adapting to the needs of different measurement ranges. The weak coupling structural beam is adopted to enhance the spatial vector discrimination ability of the multi-dimensional force of the elastomer and improve the product decoupling accuracy to meet the spatial multi-dimensional force measurement needs and improve the measurement accuracy of the multi-dimensional force sensor.

[0012] Preferably, the six self-compensating strain gauges are arranged in an orderly manner on the four force measuring surfaces of the three rectangular strain beams in a three-dimensional axisymmetric form, and there are two self-compensating strain gauges on the four external sides of the three rectangular strain beams. The twenty-four self-compensating strain gauges are arranged in a bridge assembly manner that matches the measurement requirements of spatial multi-dimensional forces and the results of stress-strain finite element theory analysis. Every four self-compensating strain gauges form a group of Wheatstone bridge measurement circuits, forming a total of six sensor weak signal outputs. The detection and processing circuit collects the six sensor weak signal outputs, and then calculates them into signal outputs required by users according to the measurement requirements, thereby realizing the multi-dimensional force measurement requirements of the wrist joint of the intelligent robotic arm.

[0013] Preferably, the distance between the top of the protective shell and the bottom of the robotic arm mounting base is less than 32 mm, the diameter of the anti-overload force measuring elastomer is not more than 70 mm, and the metal materials of all components are hard aluminum alloy, stainless steel or titanium alloy and other alloy materials that meet the sensor measurement requirements to adapt to different measurement requirements and meet the medium and low range or large range force measurement requirements. The preferred six-dimensional force measurement range is such as: Fxyz=200N; Mxyz=10Nm, and the measurement accuracy is not less than 1%.

[0014] Compared with the prior art, the advantages and positive effects of the utility model are:

[0015] In the utility model, the detection and processing circuit has a built-in high-precision measurement loop to meet the measurement requirements of the force and torque in three orthogonal directions of the wrist joint sensor. The designed assembled robotic arm mounting seat can match the vast majority of robot joint ends on the market and meet the measurement requirements of most collaborative robots and humanoid robots. It also has the characteristics of spatial multi-dimensional force recognition capability, high measurement accuracy, strong overload resistance, easy installation and quick operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a stereoscopic diagram of the main structure of an intelligent mechanical arm wrist force sensor proposed by the utility model;

[0017] Figure 2 This is a top plan view of the anti-overload force measuring elastic body part of an intelligent mechanical arm wrist force sensor proposed by the utility model;

[0018] Figure 3 This is a three-dimensional diagram of the structure of a mechanical arm mounting base and a detection and processing circuit in an intelligent mechanical arm wrist force sensor proposed by the utility model;

[0019] Figure 4 This is a three-dimensional diagram of the internal cross-sectional structure of an anti-overload force measuring elastic body part in an intelligent mechanical arm wrist force sensor proposed by the utility model.

[0020] Legend: 1. Robot arm mounting base; 2. Detection and processing circuit; 3. Anti-overload force measuring elastic body; 301. Outer shell; 302. Inner shell; 303. Outer rigid connector; 304. Inner rigid connector; 305. Anti-overload limit auxiliary mechanism; 306. Overload protection interval; 307. Rectangular strain beam; 308. Self-compensating strain gauge; 309. Beam is hollow inside; 310. Weakly coupled structural beam; 311. End tool connection interface; 4. Protective shell. DETAILED DESCRIPTION

[0021] In order to more clearly understand the above-mentioned purpose, features and advantages of the utility model, the utility model is further described below in conjunction with the accompanying drawings and embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0022] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways than those described herein. Therefore, the present invention is not limited to the specific embodiments of the following disclosure.

[0023] See also Figure 1-Figure 4The utility model provides a technical solution: an intelligent robotic arm wrist joint sensor, comprising: a robotic arm mounting seat 1, a detection processing circuit 2 is installed on the top of the robotic arm mounting seat 1 through a nut, an anti-overload force measuring elastomer 3 is arranged on the top of the robotic arm mounting seat 1, and a protective shell 4 is arranged on the top of the anti-overload force measuring elastomer 3; the anti-overload force measuring elastomer 3 comprises an inner shell 302 and an outer shell 301, an outer rigid connector 303 is arranged on the top of the outer shell 301, an inner rigid connector 304 is arranged on the top of the inner shell 302, three anti-overload limit auxiliary mechanisms 305 are arranged on the outer wall of the inner shell 302, three rectangular strain beams 307 are arranged on the outer wall of the inner shell 302, and the tops of the three anti-overload limit auxiliary mechanisms 305 are fixedly installed with end tool connection interfaces 311.

[0024] like Figure 3 As shown, the detection processing circuit 2 is provided with an integrated microprocessor MCU logic unit, and the detection processing circuit 2 can realize single-dimensional force measurement and multi-dimensional force measurement functions through the integrated microprocessor MCU logic unit, and can also be converted into other coordinate system measurement methods such as cylindrical coordinates, such as satisfying the force or torque measurement in six directions of the Cartesian coordinate system XYZ and Mx, My, Mz, and the signal output form includes analog signal output or digital signal output forms such as RS / RS / CAN.

[0025] like Figure 1 As shown, the robot arm mounting base 1 and the anti-overload force measuring elastomer 3 are installed through flange connection, which makes the device easy to replace. At the same time, the end tool connection interface 311 can be adapted and processed according to the size of the user's tool end, so it can match the vast majority of robot joint end interfaces on the market and meet the measurement needs of most collaborative robots and humanoid robots.

[0026] like Figure 2-3 As shown, the outer walls of the three rectangular strain beams 307 are respectively provided with eight self-compensating strain gauges 308. The anti-overload force measuring elastomer 3 can effectively offset the accidental force load under harsh working conditions such as collision and vibration when the robot arm is running, while meeting the mechanical measurement, thereby ensuring the reliability of the sensor and extending its service life. The self-compensating strain gauge 308 and the detection processing circuit 2 are jointly designed and installed nearby, which can meet the weak signal analysis and processing capabilities of the intelligent robot in a complex electromagnetic environment, ensure the product measurement accuracy, and improve the test response speed.

[0027] like Figure 2 and Figure 4As shown, the three rectangular strain beams 307 and the three anti-overload limit auxiliary mechanisms 305 are evenly distributed between the outer rigid connector 303 and the inner rigid connector 304, and the three rectangular strain beams 307 adopt a rectangular symmetrical structure, and the interior of the three rectangular strain beams 307 is provided with a beam interior hollow 309, and the outer wall side of the three rectangular strain beams 307 is provided with a weak coupling structure beam 310, and the inner surface wall of the three weak coupling structure beams 310 is fixedly installed on the inner surface wall of the shell 301, and the outer wall side of the three anti-overload limit auxiliary mechanisms 305 and the inner surface wall of the shell 301 are provided. There is an overload protection interval 306, and the end tool connection interface 311 is set in the force transmission path of the overload protection limit auxiliary mechanism 305. Through the effective opening and closing of the overload protection interval 306, the overload protection function of the multi-dimensional force sensor is realized, ensuring the measurement performance of the sensor under harsh working conditions such as collision and vibration, and improving the life of the sensor. At the same time, the hollow space 309 inside the beam is conducive to enhancing the stress and strain test performance and adapting to the needs of different measurement ranges. The weak coupling structure beam 310 is used to enhance the spatial vector discrimination ability of the multi-dimensional force of the elastomer and improve the product decoupling accuracy to meet the spatial multi-dimensional force measurement needs and improve the measurement accuracy of the multi-dimensional force sensor.

[0028] like Figure 2 and Figure 4 As shown, the six self-compensating strain gauges 308 are orderly arranged on the four force measuring surfaces of the three rectangular strain beams 307 in a three-dimensional axisymmetric form, and there are two self-compensating strain gauges 308 on the four external sides of the three rectangular strain beams 307. The twenty-four self-compensating strain gauges 308 are arranged in a matching bridge grouping manner according to the measurement requirements of spatial multi-dimensional force and the stress-strain finite element theory analysis results, and every four self-compensating strain gauges 308 form a group of Wheatstone bridge measurement circuits, forming a total of six sensor weak signal outputs. The detection and processing circuit 2 collects the six sensor weak signal outputs, and then solves them into the signal output required by the user according to the measurement requirements, thereby realizing the multi-dimensional force measurement requirements of the wrist joint of the intelligent robotic arm.

[0029] like Figure 1 As shown, the distance between the top of the protective shell 4 and the bottom of the robot arm mounting base 1 is less than 32mm, the diameter of the anti-overload force measuring elastomer 3 is not more than 70mm, and the metal materials of all components are hard aluminum alloy, stainless steel or titanium alloy and other alloy materials that meet the sensor measurement requirements to adapt to different measurement requirements and meet the medium and low range or large range force measurement requirements. The preferred six-dimensional force measurement range is such as: Fxyz=200N; Mxyz=10Nm, and the measurement accuracy is not less than 1%.

[0030] The detailed parameters are as follows:

[0031] a) Measuring range: Fx= Fy=Fz=200N; Mx=My= Mz=10Nm;

[0032] b) Comprehensive accuracy: 0.5%Fs~1%FS;

[0033] c) Safe overload capacity: 200%;

[0034] d) Repeatability: 0.1%FS;

[0035] e) Resolution: 0.03%FS;

[0036] f) Working temperature: -10℃~80℃;

[0037] g) Sampling frequency: 500Hz;

[0038] h) Power supply voltage: 5V-12V;

[0039] i) Communication interface: RS422 / RS485 / CAN.

[0040] The above description is only a preferred embodiment of the present invention and does not constitute any other form of limitation to the present invention. Any technician familiar with the profession may use the technical contents disclosed above to change or modify them into equivalent embodiments with equivalent changes and apply them to other fields. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. An intelligent robotic arm wrist force sensor, characterized in that: It comprises a mechanical arm mounting seat (1), a detection processing circuit (2) is mounted on the top of the mechanical arm mounting seat (1) via a nut, an anti-overload force measuring elastic body (3) is arranged on the top of the mechanical arm mounting seat (1), and a protective shell (4) is arranged on the top of the anti-overload force measuring elastic body (3); The anti-overload force measuring elastic body (3) comprises an inner shell (302) and an outer shell (301); an outer rigid connector (303) is arranged on the top of the outer shell (301); an inner rigid connector (304) is arranged on the top of the inner shell (302); three anti-overload position limiting auxiliary mechanisms (305) are arranged on the outer wall of the inner shell (302); three rectangular strain beams (307) are arranged on the outer wall of the inner shell (302); and end tool connection interfaces (311) are fixedly mounted on the tops of the three anti-overload position limiting auxiliary mechanisms (305).

2. The intelligent robotic arm wrist force sensor according to claim 1, characterized in that: The detection processing circuit (2) is provided with an integrated microprocessor MCU logic unit, and the detection processing circuit (2) can realize single-dimensional force measurement and multi-dimensional force measurement functions through the integrated microprocessor MCU logic unit.

3. The intelligent robotic arm wrist force sensor according to claim 1, characterized in that: The mechanical arm mounting seat (1) and the anti-overload force measuring elastic body (3) are installed via a flange connection.

4. The intelligent robotic arm wrist force sensor according to claim 1, characterized in that: Eight self-compensating strain gauges (308) are respectively arranged on the outer surfaces of the three rectangular strain beams (307).

5. The intelligent robotic arm wrist force sensor according to claim 1, characterized in that: The three rectangular strain beams (307) and the three anti-overload limit auxiliary mechanisms (305) are evenly distributed between the outer rigid connector (303) and the inner rigid connector (304), and the three rectangular strain beams (307) adopt a rectangular symmetrical structure, and the interior of the three rectangular strain beams (307) is provided with an internal beam hollow (309), and a weak coupling structural beam (310) is provided on one side of the outer wall of the three rectangular strain beams (307), and the inner surface walls of the three weak coupling structural beams (310) are fixedly mounted on the inner surface wall of the outer shell (301), and an overload protection interval (306) is provided between one side of the outer wall of the three anti-overload limit auxiliary mechanisms (305) and the inner surface wall of the outer shell (301).

6. The intelligent robotic arm wrist force sensor according to claim 4, characterized in that: The six self-compensating strain gauges (308) are arranged in an orderly manner on four force measuring surfaces of three rectangular strain beams (307) in a spatial three-dimensional axisymmetric form, and two self-compensating strain gauges (308) are arranged on four external sides of the three rectangular strain beams (307).

7. The intelligent robotic arm wrist force sensor according to claim 1, characterized in that: The distance between the top of the protective shell (4) and the bottom of the mechanical arm mounting seat (1) is less than 32 mm, and the diameter of the anti-overload force measuring elastic body (3) is not greater than 70 mm.

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