A multi-joint collaborative robot based on pythagorean theorem

Abstract

The utility model relates to robot technical field, concretely discloses a kind of multi-joint collaborative robot based on Pythagorean theorem, including support platform and acrylic support plate, it is characterized by: still include: the robot body of being located on support platform upper end installation, the two sides of the robot body are respectively equipped with arm mechanism, the end of the arm mechanism is equipped with end effector. This multi-joint collaborative robot based on Pythagorean theorem, by the setting of calibration mechanism, can be in robot work, using Pythagorean theorem as the basis geometric principle, can be through the length relationship of right triangle to realize accurate position calculation, the design can solve the problem that the joint of existing robot lacks effective real-time positioning calibration structure, cannot correct position deviation according to actual geometric relation in the process of operation, difficult to meet the high-precision operation demand.

Description

Technical Field

[0001] This utility model relates to the field of robotics technology, specifically to a multi-joint collaborative robot based on the Pythagorean theorem. Background Technology

[0002] Multi-joint collaborative robots, with their flexibility and versatility, are widely used in intelligent manufacturing scenarios such as sorting, palletizing, grasping, warehousing, and educational demonstrations. In these applications, the positioning accuracy of the robot's end effector directly affects the quality and efficiency of the work. Current multi-joint robot positioning mainly relies on encoders to detect the angles of each joint and calculates the end effector position through kinematic models. However, due to mechanical errors such as joint clearances and link deformations, positioning accuracy deviations are easily caused.

[0003] Currently, solutions for optimizing robot positioning accuracy mostly focus on trajectory planning algorithm optimization or the use of high-precision sensors. For example, while using Pythagorean theorem curves for trajectory planning can improve motion stability, it does not fundamentally solve the positioning deviation caused by mechanical errors; and using high-precision encoders significantly increases equipment costs. In addition, existing robots lack effective real-time positioning calibration structures between joints, making it impossible to correct positional deviations based on actual geometric relationships during operation, thus failing to meet the requirements of high-precision operations.

[0004] Therefore, there is an urgent need for a multi-joint collaborative robot structure based on the Pythagorean theorem to solve the problems of positioning accuracy being easily affected by mechanical errors and the lack of calibration mechanisms in existing technologies. Utility Model Content

[0005] The purpose of this invention is to provide a multi-joint collaborative robot based on the Pythagorean theorem, in order to solve the problem mentioned in the background art that existing robots lack an effective real-time positioning and calibration structure between joints, making it impossible to correct position deviations according to actual geometric relationships during operation and thus failing to meet the requirements of high-precision operation.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a multi-joint collaborative robot based on the Pythagorean theorem, comprising a support platform and an acrylic support plate, characterized in that it further comprises:

[0007] The robot body is mounted on the upper part of the support platform. Arm mechanisms are mounted on both sides of the robot body. An end effector is mounted at the end of the arm mechanism, and a calibration mechanism is mounted at the joint of the arm mechanism.

[0008] A Pythagorean theorem demonstration frame is set in the middle of an acrylic support plate, and the tail of the Pythagorean theorem demonstration frame is clamped by an end effector to cooperate with the arm mechanism to complete the rotation operation.

[0009] The calibration mechanism includes a detachable mounting base, a concealed laser rangefinder, and a positioning marker post mounted on the upper end of the arm mechanism. An ejector assembly is provided between the detachable mounting base and the concealed laser rangefinder.

[0010] In a multi-joint collaborative robot based on the Pythagorean theorem according to an embodiment of the present invention, the arm mechanism includes an upper arm link and a lower arm link. The connection between the upper arm link and the robot body and the connection between the lower arm link and the upper arm link are provided with joint drive components. The connection between the lower arm link and the end effector is provided with a rotation component.

[0011] The joint drive assembly includes a servo motor, a reducer, and an encoder, which are used to drive and rotate the joint axis.

[0012] In a multi-joint collaborative robot based on the Pythagorean theorem according to one embodiment of this utility model, the number of detachable mounting bases is two sets;

[0013] In this design, the detachable mounting base can be freely disassembled and installed on different models of robot arms for calibration, ensuring the operational accuracy of the end effector. It is distributed on top of two sets of joint drive components. The positioning marker posts are located on the outside of the forearm link. A hidden laser rangefinder between the upper arm and forearm links scans the hidden laser rangefinder at the other end of the upper arm link, calculates the length, and feeds it back to the data processing module. This length is taken as 'a'. Then, the distance between the positioning marker posts is measured, and this length is taken as 'b', also fed back to the data processing module. Knowing the lengths of 'a' and 'b', the length between the positioning marker post and the hidden laser rangefinder near the robot body can be deduced using the Pythagorean theorem. Simultaneously, the hidden laser rangefinder on the side closer to the robot body also measures the length of the positioning marker post and feeds it back to the data processing module for comparison. If an error exists, the angle of the joint drive components between the upper arm and forearm links is adjusted. The values ​​of 'a' and 'b' detected by the two sets of hidden laser rangefinders are received in real time, and the actual hypotenuse distance is calculated using the Pythagorean theorem. And compare c with the standard distance;

[0014] When the error value of c exceeds 0.05mm, the data processing module generates a calibration signal and sends it to the control system. The control system adjusts the corresponding joint drive component according to the deviation value, correcting the motor rotation angle until the deviation of c from the standard distance is within the allowable range. At the same time, the encoder provides real-time feedback on the joint rotation angle, forming a double verification with the calibration mechanism's detection results to ensure accurate positioning.

[0015] In a multi-joint collaborative robot based on the Pythagorean theorem according to one embodiment of the present invention, the ejection assembly includes a top plate and an electric push rod, and the top plate has a trapezoidal structure.

[0016] In a multi-joint collaborative robot based on the Pythagorean theorem according to one embodiment of this utility model, several sets of laser distance sensors are installed at equal intervals inside the hidden laser rangefinder.

[0017] In a multi-joint collaborative robot based on the Pythagorean theorem according to one embodiment of the present invention, a guide block is installed at the bottom edge of the hidden laser rangefinder, and a reset spring is installed at the upper end of the guide block.

[0018] In a multi-joint collaborative robot based on the Pythagorean theorem according to an embodiment of the present invention, the top of the detachable mounting base is provided with a storage groove adapted to the hidden laser rangefinder, and the inner wall of the storage groove is provided with a guide groove adapted to the guide block. The inside of the storage groove is provided with a moving groove adapted to the ejection component.

[0019] In this design, when the hidden laser rangefinder needs to be detected, the top plate is moved along the moving groove by an electric push rod. At this time, the bottom of the hidden laser rangefinder is squeezed, causing the hidden laser rangefinder to rise along the storage groove. At the same time, the guide block moves along the inside of the guide groove. At this time, the reset spring is compressed, and the top of the hidden laser rangefinder is lifted, so that several sets of distance measuring sensors on the outside can identify the distance between the positioning marker post and another set of hidden laser rangefinders.

[0020] In a multi-joint collaborative robot based on the Pythagorean theorem according to one embodiment of the present invention, a data processing module is provided inside the robot body; wherein the data processing module adopts an STM32 series MCU chip, and a robot head structure is installed on the top of the robot body, and a camera is provided in the middle of the robot head structure.

[0021] In the design process of this scheme, a camera can be used to control the arm mechanism to rotate the Pythagorean theorem demonstration frame, so that the Pythagorean theorem demonstration frame can display the Pythagorean theorem. The inner wall of the Pythagorean theorem demonstration frame is filled with colored liquid. During the rotation of the Pythagorean theorem demonstration frame, the liquid will flow into the corresponding rectangle, thereby determining whether the area of ​​the liquid in the corresponding rectangle conforms to the Pythagorean theorem.

[0022] Compared with the prior art, the beneficial effects of this utility model are: This multi-joint collaborative robot based on the Pythagorean theorem:

[0023] 1. High positioning accuracy: By constructing a right-angled triangle geometric positioning relationship through the Pythagorean theorem positioning calibration component, the actual distance between the upper arm link and the lower arm link is detected in real time and compared with the standard Pythagorean distance. A calibration signal is generated to correct the joint angle, effectively compensating for the positioning deviation caused by mechanical errors and significantly improving the robot's positioning accuracy.

[0024] 2. Simple structure and low cost: The calibration structure is constructed using a laser distance sensor and positioning marker posts, eliminating the need for expensive components such as high-precision encoders. Furthermore, the Pythagorean theorem calculation logic is simple, the data processing burden is small, and it is easy to implement and promote.

[0025] 3. High real-time performance: The data processing module communicates with the control system in real time, enabling continuous positioning calibration during robot operation. This avoids the lag of traditional offline calibration and ensures positioning accuracy throughout the operation.

[0026] 4. Good compatibility: The calibration mechanism can form a dual positioning guarantee with the encoder of the existing joint drive system without the need for major modifications to the main structure of the robot. It has strong compatibility and can be applied to various models of multi-joint collaborative robots. Attached Figure Description

[0027] Figure 1 This is a perspective view of the present invention;

[0028] Figure 2 This is a top view of the present invention;

[0029] Figure 3 This is a schematic diagram of the arm structure in this utility model;

[0030] Figure 4 yes Figure 3 A partial split view;

[0031] Figure 5 yes Figure 4 A partial structural diagram;

[0032] Figure 6 This is a partial structural schematic diagram of the calibration mechanism in this utility model;

[0033] Figure 7 This is a partial side sectional view of the calibration mechanism in this utility model;

[0034] Figure 8 This is a diagram showing the arm mechanism of this utility model after calibration using the Pythagorean theorem.

[0035] In the diagram: 1. Support platform; 2. Robot body; 3. Arm mechanism; 31. Upper arm link; 32. Forearm link; 33. Joint drive assembly; 34. Rotation assembly; 4. End effector; 5. Calibration mechanism; 51. Detachable mounting base; 52. Concealed laser rangefinder; 53. Ejection assembly; 54. Positioning marker post; 6. Acrylic support plate; 7. Pythagorean theorem demonstration frame. Detailed Implementation

[0036] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0037] Example:

[0038] Please see Figures 1-8 This utility model provides a technical solution: a multi-joint collaborative robot based on the Pythagorean theorem, including a support platform 1, an acrylic support plate 6, a robot body 2, an arm mechanism 3, an end effector 4, a calibration mechanism 5, and a Pythagorean theorem demonstration frame 7. The specific specifications and connection relationships of each component are as follows:

[0039] The support platform 1 is made of aluminum alloy, and the robot body 2 is fixedly installed on its upper surface with bolts to ensure the stability of the robot during operation. The acrylic support plate 6 is made of transparent acrylic sheet with a thickness of 10mm. It is horizontally fixed on the bracket on one side of the support platform 1. The middle of its platform has a reserved mounting groove that matches the Pythagorean theorem demonstration frame 7, which is used to limit the bottom of the Pythagorean theorem demonstration frame 7.

[0040] The robot body 2 adopts a vertical structure and integrates a control system, which includes a data processing module, a motor drive module, a communication module, and a power supply module. The data processing module uses an STM32F103ZET6 MCU chip, which has a high-performance ARM Cortex-M3 core with a main frequency of 72MHz and sufficient built-in Flash and RAM to meet the needs of Pythagorean theorem calculation, data comparison, and control signal generation. The robot head structure mounted on the top of the robot body 2 is a hemispherical structure with a diameter of 150mm. The camera embedded in the center can collect image information of the Pythagorean theorem demonstration frame 7 in real time and transmit it to the data processing module.

[0041] The arm mechanisms 3 symmetrically mounted on both sides of the robot body 2 have completely identical structures. Each arm mechanism 3 includes a large arm link 31 and a forearm link 32. Both the large arm link 31 and the forearm link 32 are made of carbon fiber, which can reduce the impact of link deformation on positioning accuracy. Joint drive components 33 are set at the connection between the large arm link 31 and the robot body 2, and at the connection between the forearm link 32 and the large arm link 31. The joint drive components 33 consist of a servo motor, a planetary reducer, and an incremental encoder. The servo motor adopts the MSMD022G1U model and is used to drive the large arm link 31 and the forearm link 32 to rotate precisely around the joint axis.

[0042] The rotating component 34 at the connection between the forearm link 32 and the end effector 4 adopts a structure that combines a harmonic reducer and a stepper motor. The stepper motor model is 28BYJ-48, which can drive the end effector 4 to rotate.

[0043] Among them, the end effector 4 adopts an electric gripper structure, model MHZ2-16D, with a gripping stroke of 0-16mm. The gripping angle can be adjusted by rotating component 34 to achieve stable gripping of the tail of the Pythagorean theorem demonstration frame 7.

[0044] The calibration mechanism 5 includes two sets of detachable mounting bases 51, two sets of concealed laser rangefinders 52, two sets of ejection components 53, and a set of positioning marker posts 54. The detachable mounting bases 51 are made of ABS material and are fixed to the top of the two sets of joint drive components 33 by bolts. The top of the mounting bases has a storage slot, the size of which is adapted to the concealed laser rangefinders 52. Two guide slots are symmetrically opened on the inner wall of the storage slots, and a moving slot is opened at the middle of the bottom of the storage slots.

[0045] The concealed laser rangefinder 52 uses a TOF250 laser ranging module, with multiple laser distance sensors installed at equal intervals inside. The measurement range is 0.1m-25m, and the measurement accuracy is ±0.01mm. Two guide blocks are symmetrically installed on its bottom edge. The guide blocks slide in conjunction with the guide groove on the inner wall of the storage slot. A reset spring is connected between the upper end of the guide block and the top of the storage slot. In its natural state, the concealed laser rangefinder 52 can be stored in the storage slot.

[0046] The ejection assembly 53 consists of a trapezoidal top plate and an electric push rod. The electric push rod is of model HTA2500. The trapezoidal top plate is fixed to the telescopic end of the electric push rod and installed in the movable slot at the bottom of the storage slot. When the electric push rod is energized and extends, it can push the trapezoidal top plate to move along the movable slot, thereby lifting up the hidden laser rangefinder 52.

[0047] The positioning marker post 54 is made of stainless steel, with a diameter of 10mm and a height of 50mm. It is fixed on the outer wall of the forearm link 32 near the end effector 4. Its surface is coated with a high-reflectivity coating to facilitate identification by the laser distance sensor.

[0048] Among them, the Pythagorean theorem demonstration frame 7 is made of transparent acrylic material. Its interior is divided into three interconnected rectangular chambers, which correspond to the rectangular areas corresponding to the two right-angled sides and the hypotenuse of a right triangle, respectively. The chambers are filled with red liquid, and the volume of the liquid is 1 / 2 of the chamber volume. The tail of the Pythagorean theorem demonstration frame is provided with a clamping boss for use in conjunction with the end effector 4 for clamping.

[0049] The robot operates as follows:

[0050] Calibration Preparation: After the robot is started, the power module of the control system supplies power to each component, the data processing module initializes, and sends a start signal to the electric push rod of the ejection component 53 through the communication module. After receiving the signal, the telescopic end of the electric push rod extends and pushes the trapezoidal top plate to move upward along the moving groove of the detachable mounting base 51. The trapezoidal top plate lifts up the hidden laser rangefinder 52. The guide block at the bottom of the hidden laser rangefinder 52 slides upward along the guide groove on the inner wall of the storage groove. The reset spring is compressed until the laser distance sensor at the top of the hidden laser rangefinder 52 is exposed in the storage groove. The electric push rod stops telescopically and maintains the current state.

[0051] At the same time, refer to Figure 8 As shown, the data processing module sends an initial position signal to the servo motor of the joint drive assembly 33, driving the upper arm link 31 and the lower arm link 32 to rotate to the preset calibration initial position. At this time, the two sets of hidden laser rangefinders 52 and the positioning marker post 54 form a right-angled triangle structure. The hidden laser rangefinder 52 farther away from the robot body 2 is the right-angle vertex, the line connecting the two sets of hidden laser rangefinders 52 is one right-angled side (denoted as side a), the line connecting the hidden laser rangefinder 52 farther away from the robot body 2 and the positioning marker post 54 is the other right-angled side (denoted as side b), and the line connecting the hidden laser rangefinder 52 closer to the robot body 2 and the positioning marker post 54 is the hypotenuse (denoted as side c).

[0052] The system receives the values ​​of a and b detected in real time by two sets of hidden laser rangefinders 52, and calculates the actual hypotenuse distance using the Pythagorean theorem. And compare c with the standard distance;

[0053] When the error value of c is greater than 0.05mm, it indicates that there is a deviation in the current position of the arm mechanism 3, which affects the positioning accuracy of the end effector 4. At this time, the data processing module generates a calibration signal and sends it to the motor drive module of the joint drive assembly 33 through the communication module. The motor drive module adjusts the rotation angle of the corresponding servo motor according to the deviation value in the calibration signal, thereby adjusting the relative position of the upper arm link 31 and the lower arm link 32. During the adjustment process, the hidden laser rangefinder 52 continuously detects the values ​​of a, b, and c and transmits them to the data processing module in real time until the error value of c is ≤ 0.05mm, and the deviation correction is completed.

[0054] Meanwhile, the encoder in the joint drive assembly 33 detects the rotation angle of the servo motor in real time and transmits the angle data to the data processing module through the communication module. The data processing module calculates the theoretical position of the end effector 4 according to the kinematic model and compares it with the actual position detected by the laser rangefinder based on the Pythagorean theorem to form a double verification and ensure accurate positioning.

[0055] After calibration, the data processing module sends a reset signal to the electric push rod of the ejector assembly 53. The telescopic end of the electric push rod retracts, the trapezoidal top plate resets, and the hidden laser rangefinder 52 slides down the guide groove under the elastic force of the reset spring and is stored in the storage slot of the detachable mounting base 51 to avoid damage from collisions during operation.

[0056] The communication architecture of this utility model adopts a "master-slave" structure. The internal data processing module (STM32F103ZET6 MCU) of the robot body 2 is used as the master controller, and the other components that need to communicate (including joint drive assembly 33, ejection assembly 53, hidden laser rangefinder 52, camera, rotation assembly 34, end effector 4 and external display device) are used as slave devices. The master controller establishes communication connections with the slave devices through multiple communication buses to realize bidirectional data transmission.

[0057] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi-joint collaborative robot based on the Pythagorean theorem, comprising a support platform (1) and an acrylic support plate (6), characterized in that: Also includes: The robot body (2) is installed on the upper end of the support platform (1). The robot body (2) is equipped with arm mechanisms (3) on both sides. The end effector (4) is installed at the end of the arm mechanism (3), and the calibration mechanism (5) is installed at the joint of the arm mechanism (3). The Pythagorean theorem demonstration frame (7) is set in the middle of the acrylic support plate (6), and the tail of the Pythagorean theorem demonstration frame (7) is clamped by the end effector (4) and cooperates with the arm mechanism (3) to complete the rotation operation. The calibration mechanism (5) includes a detachable mounting base (51) bolted to the outside of the arm mechanism (3), a concealed laser rangefinder (52) and a positioning marker post (54), and an ejector assembly (53) is provided between the detachable mounting base (51) and the concealed laser rangefinder (52). The arm mechanism (3) includes an upper arm link (31) and a lower arm link (32). The connection between the upper arm link (31) and the robot body (2) and the connection between the lower arm link (32) and the upper arm link (31) are provided with joint drive components (33). The connection between the lower arm link (32) and the end effector (4) is provided with a rotation component (34). The number of detachable mounting bases (51) is two sets, and they are distributed on the top of the two sets of joint drive components (33). The positioning marker post (54) is located on the outside of the forearm link (32). The ejection assembly (53) includes a top plate and an electric push rod, and the top plate has a trapezoidal structure. The top plate is in contact with the bottom of the concealed laser rangefinder (52).

2. The multi-joint collaborative robot based on the Pythagorean theorem according to claim 1, characterized in that: The concealed laser rangefinder (52) has several sets of laser distance sensors installed at equal intervals inside.

3. The multi-joint cooperative robot based on the Pythagorean theorem according to claim 1, characterized in that: The hidden laser rangefinder (52) has a guide block installed at its bottom edge, and a reset spring is installed at the top of the guide block.

4. A multi-joint collaborative robot based on the Pythagorean theorem according to claim 1, characterized in that: The top of the detachable mounting base (51) is provided with a storage slot that is compatible with the hidden laser rangefinder (52), and the inner wall of the storage slot is provided with a guide slot that is compatible with the guide block. The inside of the storage slot is provided with a moving slot that is compatible with the ejection assembly (53).

5. A multi-joint collaborative robot based on the Pythagorean theorem according to claim 1, characterized in that: The robot body (2) is equipped with a control system, which includes a data processing module, and a robot head structure is installed on the top of the robot body (2), with a camera installed in the middle of the robot head structure.

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