Polar coordinate mechanical arm system based on USART driving and using method

Abstract

The invention discloses a polar coordinate mechanical arm system based on USART driving and a using method, and belongs to the field of polar coordinate mechanical arms. The polar coordinate mechanical arm system comprises an object taking module, a chassis module and a protective shell; the polar coordinate mechanical arm comprises a polar coordinate mechanical arm body and an end effector arranged at one end of the polar coordinate mechanical arm body, the polar coordinate mechanical arm body comprises a square tube, a duct, a sliding sleeve and a flange, the shell module comprises an upper plate and a sliding sleeve edge arranged below the sliding sleeve, and the chassis module comprises a fixed base. A plurality of batteries and anti-shock brackets arranged among the batteries are arranged on the fixed base. According to the polar coordinate mechanical arm system based on USART driving and the using method, the motion precision is improved, the reliability and operation safety of the system are enhanced, the stability and function integrity are improved, and the long-term reliability of the system is achieved by protecting cables.

Description

Technical Field

[0001] The present invention relates to the technical field of polar coordinate robot arm systems, and in particular to a polar coordinate robot arm system based on USART drive and a use method thereof. Background Art

[0002] The advantages of the polar coordinate robot system mainly include the following aspects:

[0003] The polar coordinate robotic arm system has a large working space and flexible movement. It can operate in a large range and adapt to complex trajectory tasks, which can greatly improve assembly efficiency and quality. The polar coordinate robotic arm system has high positioning accuracy and good dynamic response. With the help of high-precision components and advanced algorithms, it can operate accurately and respond to instructions quickly. The polar coordinate robotic arm system is highly stable and easy to maintain. High-strength materials and modular design reduce the probability of failure and facilitate maintenance. The polar coordinate robotic arm system is energy-saving and efficient, and its operating efficiency is improved. Intelligent power management and lightweight design reduce energy consumption, and optimized design improves overall operation speed.

[0004] However, the existing serial port driven polar coordinate robot arm technology has the following disadvantages:

[0005] The communication efficiency of the serial port driven polar coordinate robot technology is low and it cannot quickly transmit large amounts of data, which easily forms a bottleneck when controlling a multi-degree-of-freedom robot. The real-time performance is poor, and the low-speed serial port communication results in insufficient data refresh rate, and the real-time performance of the dynamic control of the polar coordinate robot is poor. The anti-interference ability is weak, and the serial port communication is susceptible to electromagnetic interference in long-distance transmission or industrial environments, causing signal errors or losses. Summary of the invention

[0006] The purpose of the present invention is to provide a polar coordinate robotic arm system based on USART drive and a method of use, so as to solve the problems of low communication efficiency, inability to quickly transmit large amounts of data, and easy bottleneck formation when controlling a multi-degree-of-freedom robotic arm in the existing serial port driven polar coordinate robotic arm system technology proposed in the above background technology; poor real-time performance, low-speed serial port communication resulting in insufficient data refresh rate, and poor real-time performance of dynamic control of the polar coordinate robotic arm; weak anti-interference ability, serial port communication is susceptible to electromagnetic interference in long-distance transmission or in industrial environments, causing signal errors or losses.

[0007] To achieve the above-mentioned purpose, the present invention provides a polar coordinate robot system based on USART drive, including a picking module, a chassis module and a protective shell, the picking module includes a polar coordinate robot and a first transmission platform, the polar coordinate robot includes a polar coordinate robot body and an end effector arranged at one end of the polar coordinate robot body, the polar coordinate robot body includes a square tube, a duct is arranged at the end of the square tube away from the end effector, a sliding sleeve is sleeved in the middle of the square tube, a flange is arranged on one side of the sliding sleeve, a first drive motor is connected to the side of the flange away from the sliding sleeve, and a load-bearing bearing is arranged on the sliding sleeve; the end effector includes a link and a polyurethane sponge suction cup arranged on the link; a first small pulley and a second small pulley arranged on one side of the first small pulley are arranged on the transmission platform, and a synchronous belt is sleeved on the first small pulley and the second small pulley.

[0008] Preferably, the housing module comprises an upper plate arranged above the first transmission platform and a sliding sleeve edge arranged below the sliding sleeve.

[0009] Preferably, a synchronous wheel is arranged below the square tube, a gear is arranged below the synchronous wheel, a second driving motor is arranged at one end of the gear, and teeth meshing with the gear are arranged on the lower end surface of the square tube.

[0010] Preferably, the chassis module includes a fixed base arranged below the second drive motor, and a plurality of batteries and anti-vibration brackets arranged between the batteries are arranged on the fixed base.

[0011] Preferably, a third drive motor is arranged below the fixed base, a second transmission platform is arranged below the third drive motor, and a ball bearing is arranged on the outer side of the second transmission platform.

[0012] A method for using a polar coordinate robotic arm system based on USART drive, comprising the following steps:

[0013] S1, startup and initialization, the host computer issues instructions to the polar coordinate robot arm, allowing the polar coordinate robot arm to perform self-test and calibrate the initial position of the polar coordinate robot arm;

[0014] S2, task planning and path calculation, design task parameters to the polar coordinate robot control module, the polar coordinate robot calculates the output and plans the optimal action path;

[0015] S3, precision motion and end operation, starts each drive motor according to the task requirements, drives the polar coordinate robot arm to move, uses a closed-loop control system for real-time monitoring, and uses a polyurethane sponge suction cup to perform grasping and handling;

[0016] S4, obstacle avoidance and safety protection, real-time monitoring of the motion status and surrounding environment, when a possible collision or overload is detected, the movement of the polar coordinate robot arm is suspended and an alarm is issued;

[0017] S5, reset and shut down, reset the polar coordinate robot arm according to the set path and enter the sleep state.

[0018] Preferably, the control algorithm used in the polar coordinate robot arm movement process is fuzzy PID control, wherein the specific formula of the logic control module is:

[0019] e(t)=θ desired -θ current ;

[0020] ec(t)=e(t)-e(t-1);

[0021] Where e(t) is the error between the actual position and the expected position of the polar coordinate manipulator at time t; θ is the angle of movement of the polar coordinate manipulator; θ desired Feedback the actual position of the polar coordinate robot arm to the drive motor; θ current is the expected position; ec(t) is the rate of change of the error;

[0022] Conversion formula from polar coordinates to Cartesian formula:

[0023] x = r·cos(θ);

[0024] y = r·sin(θ);

[0025] z=z;

[0026] Where r is the radial distance from the origin to the point; θ is the angle between the x-axis and the x-axis in the xy plane (usually expressed in radians or degrees); and z represents the height of the polar coordinate robot on the z-axis.

[0027] Preferably, the overall transfer function of the closed-loop control system in S3 can be expressed as:

[0028]

[0029] Among them, K p is the proportional gain; K i is the integral gain; K d is the differential gain; G p (s) is the transfer function of the controlled object; U(s) is the controller output; E(s) is the Laplace transform of the error signal; s is the complex variable in the Laplace transform, s=σ+jω includes the real part σ and the imaginary part jω.

[0030] Preferably, the traditional PID controller output formula is:

[0031]

[0032] Among them, K p is the proportional gain; K i is the integral gain; Kd is the differential gain.

[0033] Therefore, the present invention adopts the above-mentioned polar coordinate robot system based on USART drive and the use method, which has the following beneficial effects:

[0034] (1) Improve motion accuracy through the combination of high-precision servo motors and fuzzy PID closed-loop control algorithms. In addition, the torque sensor can monitor the external environment in real time during operation. When abnormal resistance or collision is detected, the protection mechanism will be triggered to effectively avoid equipment damage and safety hazards, thereby enhancing the reliability and operational safety of the system;

[0035] (2) The durability and fatigue resistance of the system are improved by using high-strength materials and precision processing technology, combined with protective shell and anti-seismic design. The multi-layer protection design effectively reduces the loss caused by external impact or long-term operation, greatly reduces the maintenance frequency and maintenance cost, and reduces the downtime of the system;

[0036] (3) The electronic components are firmly mounted through anti-vibration fixing brackets and shock-absorbing mounting plates, which can maintain their stability and functional integrity even if they are subjected to vibration or impact during the operation of the robot arm. The efficient cable management channel design avoids cable wear and signal interference, and improves the long-term reliability of system operation;

[0037] (4) By adopting high-efficiency brushless motors and intelligent power management modules, the robot arm can dynamically adjust power output according to the actual task load and reduce unnecessary energy consumption. Combined with lightweight design and optimized motion control algorithms, the robot arm can further extend its battery life while operating efficiently, improving overall operating efficiency.

[0038] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0040] Figure 2 This is a schematic diagram of the structure of a fixed base according to an embodiment of the present invention;

[0041] Figure 3 It is a schematic diagram of the composition of an embodiment of the present invention;

[0042] Figure 4 is a flow chart of an embodiment of the present invention;

[0043] Figure 5 A flowchart of the operation of the robot arm according to an embodiment of the present invention;

[0044] Reference numerals

[0045] 1.1. Upper plate; 2. Synchronous belt; 3. First small pulley; 4. Second small pulley; 5. Duct; 6. Arm plate; 7. Synchronous wheel; 8. First drive motor; 9. Load-bearing bearing; 10. Second drive motor; 11. Polyurethane sponge suction cup; 12. Flange bearing; 13. Ball bearing; 14. Square tube; 15. Sleeve; 16. Flange; 17. Sleeve edge; 18. Third drive motor; 19. Link; 20. Gear; 21. Battery; 22. Fixed base; 23. Anti-seismic bracket; 24. First transmission platform; 25. Second transmission platform. DETAILED DESCRIPTION

[0046] The following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] See also Figure 1-Figure 2 A polar coordinate manipulator system based on USART drive includes a picking module, a chassis module and a protective shell. The picking module includes a polar coordinate manipulator and a first transmission platform. The polar coordinate manipulator includes a polar coordinate manipulator body and an end effector arranged at one end of the polar coordinate manipulator body. The polar coordinate manipulator body includes a square tube 14, which is a hollow glass fiber tube. A duct 5 is arranged at one end of the square tube 14 away from the end effector, and the duct 5 has its own drive. A sleeve 15 is sleeved in the middle of the square tube 14, a flange 16 is arranged on one side of the sleeve 15, and a first drive motor 8 is connected to the side of the flange 16 away from the sleeve 15. The first drive motor 8 is an EC-A4310 DC brushless motor. A load-bearing bearing 9 is arranged on the sleeve 15, and the load-bearing bearing 9 is a 625 bearing. An arm plate 6 is arranged on the side of the polar coordinate manipulator body. A flange bearing 12 corresponding to the flange 16 is arranged below the flange 16.

[0048] The end effector includes a link 19 and a polyurethane sponge suction cup 11 arranged on the link 19; a first small pulley 3 and a second small pulley 4 arranged on one side of the first small pulley 3 are arranged on the first transmission platform, and a synchronous belt 2 is sleeved on the first small pulley 3 and the second small pulley 4. The synchronous belt 2 is a 3m-146 tooth synchronous belt 2, the first small pulley 3 is a 3m-130 small pulley, and the second small pulley 4 is a 3m-20 small pulley. The first transmission platform remains stationary relative to the chassis module when the polar coordinate robot arm rotates.

[0049] The housing module includes an upper plate 1 arranged above the first transmission platform and a sleeve edge 17 arranged below the sleeve 15 .

[0050] A synchronous wheel 7 is arranged below the square tube 14 , a gear 20 is arranged below the synchronous wheel 7 , a second driving motor 10 is arranged at one end of the gear 20 , and teeth meshing with the gear 20 are arranged on the lower end surface of the square tube 14 .

[0051] The chassis module includes a fixed base 22 disposed below the second drive motor 10, on which a plurality of batteries 21 and an anti-vibration bracket 23 disposed between the batteries 21 are disposed. The second drive motor 10 is an EC-A2806 DC brushless motor. The battery is a 24V DJI battery.

[0052] A third drive motor 18 is arranged below the fixed base 22, a second transmission platform is arranged below the third drive motor 18, and a ball bearing 13 is arranged outside the second transmission platform. The first transmission platform is provided with a structure consistent with the first transmission platform. The third drive motor 18 is an EC-A8120 shaft-connected DC brushless motor.

[0053] The EC-A2806 motor module drives the arm to move up and down, the EC-A8120 motor module drives the arm to rotate left and right, and the EC-A4310 motor module drives the arm to move forward and backward. A self-made ball bearing 13 is installed for left and right and up and down rotation to reduce the lateral damping and longitudinal damping during left and right rotation. At the same time, grease is applied during routine maintenance to increase the service life of the device.

[0054] The polyurethane sponge ensures the accuracy and reliability of the object-picking action within a certain range. The polar coordinate robot arm uses the polyurethane sponge suction cup 11 to perform grasping and handling, forming a reliable negative pressure adsorption when contacting the target object, and stably grasping the object. Link 19 uses titanium alloy (Ti-6Al-4V) to achieve a better balance between weight and strength, and improve the overall operational flexibility and efficiency of the robot arm.

[0055] During the operation of the robot arm, the 3m-146 tooth synchronous belt 2 is mainly used to transmit power. Because it has a large number of teeth and a pitch specification of 3m, and the tooth shape is an arc tooth, it can ensure the accuracy and stability of the transmission when meshing with the pulley, reduce slippage, and ensure the reliability of power transmission. The 3m-130 small pulley can adjust the angular velocity when the polar coordinate robot arm rotates left and right by cooperating with the synchronous belt 2. The rotational angular velocity generated by the polar coordinate robot arm can be converted into a motion speed suitable for other parts of the system to ensure that the power transmission and motion execution of the entire polar coordinate robot arm system meet the design requirements. The 3m-20 small pulley plays a role in situations where more precise adjustment of the angular velocity is required. For example, in some operating scenarios that require high motion accuracy of the polar coordinate robot arm, it can make more detailed adjustments to the rotation speed of the polar coordinate robot arm according to system requirements to achieve precise motion control. When the polar coordinate robot moves, the synchronous wheel 7 ensures the synchronization of transmission with the help of the torque transmission shaft. In the transmission link of the upper platform, the synchronous wheel 7 can transmit the power of the transmission shaft to the upper synchronous belt 2, and through the motion compensation mechanism, it can effectively offset the disturbance of the platform caused by the rotation of the polar coordinate robot, so that the platform remains stationary relative to the chassis when the polar coordinate robot rotates, thereby ensuring that the camera platform above can stably aim at the target without being affected by the movement of the robot.

[0056] The end effector is connected to the end of the polar coordinate robot arm through an interface, the chassis part is connected to the main body of the polar coordinate robot arm through bolts and load bearing 9, and the protective shell is fixed to the robot arm through embedded buckles and bolts. The connection interface between the end effector and the end of the polar coordinate robot arm is made of high-strength titanium alloy, which can maintain the integrity and stability of the structure under complex working conditions and large load conditions, effectively resist various external forces, prevent deformation, fracture and other failures in the interface part, and combine with the mechanical lock design to ensure convenient installation and replacement. The fixed base 22 is connected to the main body of the polar coordinate robot arm through bolts and load bearing 9 to provide the overall support force and rotation flexibility of the robot arm. The load bearing 9 part of the base module is combined with the main frame of the robot arm through precision machining to ensure that the rotation movement of the robot arm is smooth and low friction, while avoiding the risk of tipping. The shell module is fixed to the frame of the polar coordinate robot arm through embedded buckles and bolts, covering the motor drive and motor. This connection method is not only convenient for disassembly and maintenance, but also effectively protects the internal components from external dust, moisture and mechanical shock.

[0057] like Figure 3-Figure 5 , a method for using a polar coordinate robotic arm system based on USART drive, comprising the following steps:

[0058] S1, startup and initialization, the host computer issues instructions to the polar coordinate robot arm, allowing the polar coordinate robot arm to perform self-test and calibrate the initial position of the polar coordinate robot arm;

[0059] S2, task planning and path calculation, design task parameters to the polar coordinate robot control module, the polar coordinate robot calculates the output and plans the optimal action path;

[0060] S3, precise movement and end operation, start each drive motor according to the task requirements, drive the polar coordinate manipulator to move, use a closed-loop control system for real-time monitoring, and use the polyurethane sponge suction cup 11 to perform grasping and handling;

[0061] S4, obstacle avoidance and safety protection, real-time monitoring of the motion status and surrounding environment, when a possible collision or overload is detected, the movement of the polar coordinate robot arm is suspended and an alarm is issued;

[0062] S5, reset and shut down, reset the polar coordinate robot arm according to the set path and enter the sleep state.

[0063] The control algorithm used in the polar coordinate robot arm movement process is fuzzy PID control, and the specific formula of the logic control module is:

[0064] e(t)=θ desired -θ current ;

[0065] ec(t)=e(t)-e(t-1);

[0066] Where e(t) is the error between the actual position and the expected position of the polar coordinate manipulator at time t; θ is the angle of movement of the polar coordinate manipulator; θ desired Feedback the actual position of the polar coordinate robot arm to the drive motor; θ current is the expected position; ec(t) is the rate of change of the error;

[0067] Conversion formula from polar coordinates to Cartesian formula:

[0068] x = r·cos(θ);

[0069] y = r·sin(θ);

[0070] z=z;

[0071] Where r is the radial distance from the origin to the point; θ is the angle between the x-axis and the x-axis in the xy plane (usually expressed in radians or degrees); and z represents the height of the polar coordinate robot on the z-axis.

[0072] Specifically, the drive motor drives the polar coordinate robot arm by receiving serial port data. The robot arm has three degrees of freedom, namely the radial distance r controlled by the EC-A2806 joint module, the angle θ controlled by the EC-A8120 joint module, and the height z controlled by the EC-A4310 joint module. The module reduces overshoot and oscillation through fuzzy PID control, and responds quickly and smoothly to complete the required reaction angle.

[0073] The overall transfer function of the closed-loop control system in S3 can be expressed as:

[0074]

[0075] Among them, K p is the proportional gain; K i is the integral gain; K d is the differential gain; G p (s) is the transfer function of the controlled object; U(s) is the controller output; E(s) is the Laplace transform of the error signal; s is the complex variable in the Laplace transform, s=σ+jω includes the real part σ and the imaginary part jω.

[0076] The traditional PID controller output formula is:

[0077]

[0078] Among them, K p is the proportional gain; K i is the integral gain; K d is the differential gain.

[0079] Therefore, the present invention adopts the above-mentioned polar coordinate manipulator system and use method based on USART drive, and improves the motion accuracy through a high-precision integrated servo motor module equipped with dual encoders and torque sensors, that is, a combination of a joint module and a fuzzy PID closed-loop control algorithm. In addition, the torque sensor can monitor the external environment in real time during operation, has a protection mechanism, and enhances the reliability and operational safety of the system; the electronic components are stably installed through anti-seismic fixed brackets and shock-absorbing mounting plates to improve stability and functional integrity. In addition, the cable management channel design made of glass fiber laminate avoids cable wear and signal interference, and protects the long-term reliability of the cable realization system.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A polar coordinate robotic arm system based on USART drive, characterized by: It includes a picking module, a chassis module and a protective shell. The picking module includes a polar coordinate robot arm and a first transmission platform. The polar coordinate robot arm includes a polar coordinate robot arm body and an end effector arranged at one end of the polar coordinate robot arm body. The polar coordinate robot arm body includes a square tube. A duct is arranged at the end of the square tube away from the end effector. A sliding sleeve is sleeved in the middle of the square tube. A flange is arranged on one side of the sliding sleeve. The side of the flange away from the sliding sleeve is connected to a first drive motor, and a load-bearing bearing is arranged on the sliding sleeve; the end effector includes a link and a polyurethane sponge suction cup arranged on the link; a first small pulley and a second small pulley arranged on one side of the first small pulley are arranged on the first transmission platform, and a synchronous belt is sleeved on the first small pulley and the second small pulley.

2. A polar coordinate robotic arm system based on USART drive according to claim 1, characterized in that: The housing module comprises an upper plate arranged above the first transmission platform and a sliding sleeve edge arranged below the sliding sleeve.

3. A polar coordinate robotic arm system based on USART drive according to claim 2, characterized in that: A synchronous wheel is arranged below the square tube, a gear is arranged below the synchronous wheel, a second driving motor is arranged at one end of the gear, and teeth meshing with the gear are arranged on the lower end surface of the square tube.

4. A polar coordinate robotic arm system based on USART drive according to claim 3, characterized in that: The chassis module comprises a fixed base arranged below the second driving motor, on which a plurality of batteries and anti-vibration brackets arranged between the batteries are arranged.

5. A polar coordinate robotic arm system based on USART drive according to claim 4, characterized in that: A third driving motor is arranged below the fixed base, a second transmission platform is arranged below the third driving motor, and a ball bearing is arranged outside the second transmission platform.

6. A method for using a polar coordinate manipulator system based on USART drive as described in any one of claims 1 to 5, characterized in that: The following steps are involved: S1, startup and initialization, the host computer issues instructions to the polar coordinate robot arm, allowing the polar coordinate robot arm to perform self-check and calibrate the initial position of the polar coordinate robot arm; S2, task planning and path calculation, design task parameters to the polar coordinate robot control module, the polar coordinate robot calculates the output and plans the optimal action path; S3, precision motion and end operation, starts each drive motor according to the task requirements, drives the polar coordinate robot arm to move, uses a closed-loop control system for real-time monitoring, and uses a polyurethane sponge suction cup to perform grasping and handling; S4, obstacle avoidance and safety protection, real-time monitoring of the motion status and surrounding environment, when a possible collision or overload is detected, the movement of the polar coordinate robot arm is suspended and an alarm is issued; S5, reset and shut down, reset the polar coordinate robot arm according to the set path and enter the sleep state.

7. The method for using the polar coordinate robotic arm system based on USART drive according to claim 6, characterized in that: The control algorithm used in the polar coordinate robot arm movement process is fuzzy PID control, and the specific formula of the logic control module is: e(t)=θ desired -θ current ; ec(t)=e(t)-e(t-1); Where e(t) is the error between the actual position and the expected position of the polar coordinate manipulator at time t; θ is the angle of movement of the polar coordinate manipulator; θ desired Feedback the actual position of the polar coordinate robot arm to the drive motor; θ current is the expected position; ec(t) is the rate of change of the error; Conversion formula from polar coordinates to Cartesian formula: x = r·cos(θ); y = r·sin(θ); z=z; Where r is the radial distance from the origin to the point; θ is the angle between the x-axis and the x-axis in the xy plane; and z represents the height of the polar coordinate robot on the z-axis.

8. The method for using the polar coordinate robotic arm system based on USART drive according to claim 7, characterized in that: The overall transfer function of the closed-loop control system in S3 can be expressed as: Among them, K p is the proportional gain; K i is the integral gain; K d is the differential gain; G p (s) is the transfer function of the controlled object; U(s) is the controller output; E(s) is the Laplace transform of the error signal; s is the complex variable in the Laplace transform, s=σ+jω includes the real part σ and the imaginary part jω.

9. The method for using the polar coordinate robotic arm system based on USART drive according to claim 8, characterized in that: The traditional PID controller output formula is: Among them, K p is the proportional gain; K i is the integral gain; K d is the differential gain.

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