High-precision full-closed-loop rotation control system, method and device for dragging multiple suction nozzle rods by single motor and electronic equipment

Abstract

The invention discloses a high-precision full-closed-loop rotation control system, method and device for dragging multiple suction nozzle rods by a single motor and electronic equipment, and belongs to the technical field of motor dragging control. The system comprises an R-axis motor, an R-axis driver and an angle sensor, a motor shaft of the R-axis motor is in transmission connection with a suction nozzle rod, the suction nozzle rod is provided with a mounting head, the angle sensor is arranged on the rotation collection side of the motor shaft, the angle sensor is in communication connection with the R-axis driver, and the R-axis driver is in communication connection with the R-axis motor; the angle sensor is used for collecting the rotation position of the motor shaft and generating the digital angle of the motor shaft; the R-axis driver is used for determining an actual rotation angle of the motor shaft according to the digital angle and generating a driving signal according to the actual rotation angle and an angle set value of the R-axis motor; and the R-axis motor is used for responding to the driving signal and controlling the mounting head to perform element mounting through the motor shaft and the suction nozzle rod. According to the system, the component mounting precision of the chip mounter is improved.

Description

Technical Field

[0001] This application belongs to the field of motor drive control technology, and in particular relates to a high-precision fully closed-loop rotation control system, method, device and electronic equipment for single motor driving multiple suction nozzle rods. Background Technology

[0002] Surface Mount Technology (SMT) is currently the core technology in the mainstream electronic component assembly industry. Its advantages include high density, small size, light weight, high reliability, high precision, and high automation, meeting the needs of most assembly applications. High-precision pick-and-place machines, as key equipment in SMT production lines, primarily use their placement heads to pick up and place components. The placement accuracy directly affects and determines the overall precision of the pick-and-place machine.

[0003] Placement accuracy refers to the maximum permissible deviation between the component leads and the center of the corresponding pads after the component is placed. Placement accuracy consists of two types of errors: translational error and rotational error.

[0004] Translational error characterizes the deviation of the component center, mainly stemming from the inaccuracy of the XY-axis gantry motion system or misidentification by the vision system, including errors in displacement, calibration, and axis orthogonality. Inaccuracy of the component centering mechanism is also a factor if it fails to precisely align the component center with the axis of the placement tool.

[0005] Rotational error is used to characterize the angle of component deviation. It comes from the inaccuracy of the component centering mechanism and the angle error of the placement head rotation. The angle error also affects the translational error.

[0006] The method used by pick-and-place machines to correct the angle of components is to drive the nozzle rod to rotate via the R-axis motor on the placement head. How to improve the accuracy of component placement by pick-and-place machines is an urgent problem to be solved. Summary of the Invention

[0007] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a high-precision fully closed-loop rotation control system, method, apparatus, and electronic equipment for single-motor driven multi-nozzle rods, which improves the accuracy of component placement in pick-and-place machines.

[0008] Firstly, this application provides a high-precision, fully closed-loop rotation control system for a single motor driving multiple suction nozzle rods. Includes R-axis motor, R-axis driver and angle sensor; The motor shaft of the R-axis motor is connected to the nozzle rod via a drive. The nozzle rod is equipped with a mounting head. The angle sensor is located on the rotation acquisition side of the motor shaft. The angle sensor is communicatively connected to the R-axis driver. The R-axis driver is communicatively connected to the R-axis motor. The angle sensor is used to acquire the rotational position of the motor shaft and generate a digital angle of the motor shaft; The R-axis driver is used to determine the actual rotation angle of the motor shaft based on the digital angle, and to generate a drive signal based on the actual rotation angle and the angle setting value of the R-axis motor. The R-axis motor is used to respond to the drive signal and control the mounting head to perform component placement via the motor shaft and the nozzle rod.

[0009] According to one embodiment of this application, the angle sensor includes a Hall element, an analog-to-digital conversion module, and an arctangent calculation module that are sequentially connected in communication: The Hall element is used to generate a voltage signal based on the rotational position of the motor shaft; The analog-to-digital converter module is used to convert the voltage signal back into two orthogonal digital signals; The arctangent calculation module is used to determine the digital angle of the motor shaft based on the orthogonal digital information.

[0010] According to one embodiment of this application, the angle sensor is an off-axis magnetic encoder chip, model KTH7812.

[0011] According to one embodiment of this application, the angle sensor further includes a permanent magnet; The permanent magnet is sleeved on the gear between the suction nozzle rod and the motor shaft. The permanent magnet is arranged opposite to the Hall element. The air gap between the permanent magnet and the Hall element is set to 0.5mm-5mm. The installation deviation between the permanent magnet and the Hall element is set to 0.5mm-2mm.

[0012] According to one embodiment of this application, the R-axis driver communicates with the angle sensor via a serial peripheral interface.

[0013] According to one embodiment of this application, the clock pin of the microcontroller in the R-axis driver is connected to the clock pin of the angle sensor, the communication pin of the microcontroller in the R-axis driver is connected to the communication pin of the angle sensor, the data output pin of the microcontroller in the R-axis driver is connected to the data output pin of the angle sensor, the data input pin of the microcontroller in the R-axis driver is connected to the data input pin of the angle sensor, and the three-phase power pins of the microcontroller in the R-axis driver are respectively connected to the three-phase power pins of the angle sensor through the resistors in the first resistor assembly. In the R-axis driver, the Hall signal pins of the microcontroller are connected to the Hall signal pins of the angle sensor through individual resistors in the second resistor assembly.

[0014] According to one embodiment of this application, the clock pin, the communication pin, the data output pin, and the data input pin are respectively connected to the power supply terminal through individual resistors in the third resistor assembly; or, The clock pin, the communication pin, the data output pin, and the data input pin are all connected to the power supply terminal.

[0015] Secondly, this application provides a high-precision fully closed-loop rotation control method for a single motor driving a multi-nozzle rod. This method is applied to the high-precision fully closed-loop rotation control system for a single motor driving a multi-nozzle rod as described in the first aspect. The method includes: The rotational position of the motor shaft is acquired by an angle sensor, and a digital angle of the motor shaft is generated. The R-axis driver determines the actual rotation angle of the motor shaft based on the digital angle, and generates a drive signal based on the actual rotation angle and the angle setting value of the R-axis motor. The R-axis motor responds to the drive signal, and the mounting head is controlled by the motor shaft and the nozzle rod to perform component mounting.

[0016] Thirdly, this application provides a high-precision fully closed-loop rotation control device for a single motor driving a multi-nozzle rod, used to control the high-precision fully closed-loop rotation control system for a single motor driving a multi-nozzle rod as described in the first aspect, the device comprising: The first processing module is used to acquire the rotational position of the motor shaft through an angle sensor and generate a digital angle of the motor shaft; The second processing module is used to determine the actual rotation angle of the motor shaft based on the digital angle using the R-axis driver, and to generate a drive signal based on the actual rotation angle and the angle setting value of the R-axis motor. The third processing module is used to control the mounting head to perform component mounting by responding to the drive signal via the R-axis motor, through the motor shaft and the nozzle rod.

[0017] Fourthly, this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the high-precision fully closed-loop rotation control method for single-motor driven multi-nozzle rods as described in the first aspect above.

[0018] Fifthly, this application provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the high-precision fully closed-loop rotation control method for single-motor driven multi-nozzle rods as described in the first aspect above.

[0019] In a sixth aspect, this application provides a chip, which includes a processor and a communication interface, the communication interface being coupled to the processor, and the processor being used to run programs or instructions to implement the high-precision fully closed-loop rotation control method for single-motor driven multi-nozzle rods as described in the first aspect.

[0020] In a seventh aspect, this application provides a computer program product, including a computer program that, when executed by a processor, implements the high-precision fully closed-loop rotation control method for single-motor driven multi-nozzle rods as described in the first aspect above.

[0021] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application.

[0022] This application provides a high-precision fully closed-loop rotary control system, method, apparatus, and electronic equipment for single-motor driven multi-nozzle rods, which has the following advantages over the prior art: (1) The rotational position of the motor shaft is directly measured by the angle sensor to form a closed-loop control, thereby eliminating the errors caused by gear backlash, transmission belt elastic deformation and wear in traditional open-loop or semi-closed-loop control. Without occupying a lot of space and without increasing the XY load, the accuracy of the pick-and-place machine for mounting components is improved.

[0023] (2) The off-axis magnetic encoder chip works by detecting changes in the magnetic field. The magnetic field is not affected by common non-magnetic contaminants, so it has extremely high reliability and environmental tolerance, ensuring continuous and stable operation on key equipment such as SMT production lines and reducing maintenance costs. Attached Figure Description

[0024] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is one of the structural diagrams of a pick-and-place machine provided by existing technology; Figure 2 This is the second structural diagram of a pick-and-place machine provided by existing technology; Figure 3 This is one of the structural schematic diagrams of the high-precision fully closed-loop rotary control system for single-motor driven multi-nozzle rods provided in the embodiments of this application; Figure 4 This is the second schematic diagram of the high-precision fully closed-loop rotary control system for single-motor driven multi-nozzle rods provided in the embodiments of this application; Figure 5 This is one of the schematic diagrams showing the installation positions of the Hall element and permanent magnet in the off-axis magnetic encoder chip provided in this application embodiment; Figure 6 This is the second schematic diagram showing the installation positions of the Hall element and permanent magnet in the off-axis magnetic encoder chip provided in this application embodiment; Figure 7 This application provides a schematic diagram illustrating the connection relationship between the angle sensor and the R-axis driver in an embodiment. Figure 8 A flowchart illustrating the high-precision fully closed-loop rotation control method for a single motor driving multiple suction nozzle rods provided in this application embodiment; Figure 9 This is a schematic diagram of the structure of the high-precision fully closed-loop rotation control device for single-motor driven multi-nozzle rods provided in the embodiments of this application; Figure 10 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application.

[0025] Figure label: Driven wheel 1; belt 2; drive wheel 3; first R-axis motor 4; Z-axis motor 5; second R-axis motor 6. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0027] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0028] Existing technologies include, for example Figure 1 and Figure 2 Two options.

[0029] like Figure 1 As shown, a first R-axis motor 4 drives multiple nozzle rods to rotate via a belt 2 or gears. During mounting, the multiple nozzle rods are mounted sequentially. The first R-axis motor 4 first rotates to the angle required for mounting the first nozzle rod, and then the first nozzle rod moves downward to complete the mounting action. The R-axis then rotates to the angle required for mounting the second nozzle rod, and the mounting action is completed. This process continues until all nozzle rods are mounted. All mounting actions are completed by adjusting the angle through the back-and-forth rotation of the R-axis.

[0030] Although this solution requires fewer first R-axis motors 4, saving head space and reducing head weight, and the load on the XY-axis gantry motion system is smaller, allowing for faster speed and acceleration, and more precise motion control, it suffers from several drawbacks. All nozzle rods must wait for the R-axis to rotate sequentially before being applied, resulting in slow application speed. Furthermore, the first R-axis motor 4's transmission is via belts and gears, and its semi-closed-loop control means that prolonged back-and-forth motion may cause wear and tear, creating transmission backlash and affecting rotational accuracy.

[0031] like Figure 2 As shown, the placement action of the pick-and-place machine is completed by the placement head. The Z-axis motor 5 and the second R-axis motor 6 mounted on the placement head are mainly responsible for the rotation and placement of components. The entire placement head is mounted on the X-arm, which is used for movement in the X direction. The X-arm is connected to the Y-arm, and the movement of the Y-arm drives the movement of the entire X-arm in the Y direction. Therefore, the movement of the XY-arm can move the placement head to any position in the XY plane within the XY stroke. When the XY arm moves to the placement position of the component, the R-axis rotates to the required placement angle, and then the Z-axis moves downward to complete the placement action. One second R-axis motor 6 drives one nozzle rod to rotate. The second R-axis motor 6 can simultaneously rotate to adjust the placement angle of the corresponding nozzle rod. Then, waiting for the XY arm to move to the placement point, the placement is completed. If the placement position and the distance between the nozzle rods are appropriate, the effect of simultaneous picking and placement can be achieved.

[0032] While this solution allows for simultaneous rotation of all nozzle rods, enabling simultaneous picking and application in special cases, it is faster and more accurate than the first solution. However, it requires multiple motors, resulting in a heavier head, more space requirements, more difficult head wiring harness management, and a higher load on the XY-axis gantry motion system.

[0033] The high-precision fully closed-loop rotation control system, the high-precision fully closed-loop rotation control method, the high-precision fully closed-loop rotation control device, the electronic equipment, and the readable storage medium provided in this application will be described in detail below with reference to the accompanying drawings and through specific embodiments and application scenarios.

[0034] like Figure 3 As shown, this high-precision fully closed-loop rotation control system for a single motor driving a multi-nozzle rod includes: The system comprises an R-axis motor 310, an R-axis driver 320, and an angle sensor 330. The motor shaft of the R-axis motor 310 is connected to the nozzle rod, which is equipped with a mounting head. The angle sensor 330 is located on the rotation acquisition side of the motor shaft and is communicatively connected to the R-axis driver 320. The R-axis driver 320 is also communicatively connected to the R-axis motor 310. The angle sensor 330 is used to acquire the rotational position of the motor shaft and generate a digital angle of the motor shaft; The R-axis driver 320 is used to determine the actual rotation angle of the motor shaft based on the digital angle, and to generate a drive signal based on the actual rotation angle and the angle setting value of the R-axis motor 310. The R-axis motor 310 is used to respond to the drive signal and control the mounting head to perform component mounting through the motor shaft and the nozzle rod.

[0035] like Figure 4 As shown, the R-axis motor is a high-performance servo motor or stepper motor, and its motor shaft is connected to the nozzle rod via a gear reduction mechanism. The nozzle rod is equipped with a mounting head for picking up and placing components. One R-axis motor can simultaneously drive multiple nozzle rods to rotate synchronously through this transmission mechanism, greatly improving production efficiency.

[0036] To achieve fully closed-loop control, the angle sensor is directly installed on the rotation acquisition side of the motor shaft to directly measure the real-time rotation angle of the motor shaft itself, rather than measuring it from the end of the transmission chain.

[0037] The angle setting is determined based on the received external instructions.

[0038] In actual execution, after the R-axis motor returns to zero, the MCU reads the current angle data via SPI and stores it as the zero point. When the motor starts to rotate after receiving an external command, the angle sensor collects the rotation position of the motor shaft in real time, converts it into a high-resolution digital angle value, and transmits it to the R-axis driver in real time via a high-speed serial communication interface.

[0039] The microcontroller unit (MCU) inside the R-axis driver receives this digital angle value as a feedback signal for the actual rotation angle of the motor shaft. The MCU monitors the actual rotation angle data of the R-axis in real time, obtaining a 16-bit binary digital angle R2, from which the actual output rotation angle R3 can be calculated. The value of R3 ranges from 0 to 360°.

[0040] The microcontroller compares the rotation angle R3 with the angle setpoint (i.e., the target angle the motor shaft is expected to rotate to) sent by the host computer and calculates the position error. Based on this error, the microcontroller uses a proportional-integral-differential (PID) control algorithm to generate a corresponding pulse-width modulation (PWM) wave drive signal. It repeatedly adjusts the output torque and speed of the motor, driving the motor shaft, gear mechanism, and nozzle rod to move. Ultimately, it drives the mounting head to move towards the target angle position until the rotation angle R3 equals the angle setpoint R4. By monitoring the output at the load end, the influence of intermediate transmission errors is eliminated, achieving precise positioning. Theoretically, a deviation of 0.015° can be achieved.

[0041] It should be noted that semi-closed-loop control only uses motor-side sensors (such as encoders or Hall sensors) to provide feedback on the motor's output speed or position, without directly monitoring the actual movement of the load. The system adjusts the drive signal by comparing the motor feedback value with the set value. Full closed-loop control, on the other hand, adds a load-side sensor to the semi-closed-loop control, directly measuring the actual position or speed of the load and comparing this feedback with the set value to form a closed-loop adjustment. For example, conventional transmission mechanisms using gears and belts have a transmission ratio. Assuming a transmission ratio of 1.2 and a target angle of 45°, the motor needs to rotate 37.5° (37.5 * 1.2) to complete the 45° rotation. However, if there is a 0.2 gap, it will cause an error in the angle. This application adds an external magnetic encoder position as input in addition to the motor's built-in position loop, increasing load-side input monitoring for closed-loop adjustment. Based on the original single-motor-driven multi-nozzle rod, a higher-precision external angle sensor is introduced to monitor the actual rotation angle of the R-axis, forming an external position loop. This replaces the previous semi-closed-loop control with full closed-loop control, achieving higher precision control. Only one sensor acquisition board needs to be installed.

[0042] The PID algorithm will be described in detail below.

[0043] An auxiliary encoder installed at the tail of the R-axis motor serves as a speed loop to acquire high-frequency instantaneous speed and micro-vibration signals of the R-axis motor. A high-dynamic torque sensor is connected in series between the motor shaft and the gearbox to monitor the real torque value output by the motor in real time. Temperature sensors are integrated inside the R-axis drive and near the gearbox to serve as a torque observation loop to monitor the thermal state of the system.

[0044] Through the above settings, a multi-loop collaborative control architecture including an inner speed loop, an outer position loop, and a torque observation loop was constructed. The inner speed loop greatly improves the dynamic responsiveness and rigidity of the system and can suppress disturbances more quickly.

[0045] Understandably, in the position loop, position error for: in, The target position (set value) at the kth sampling time; The actual position of the motor shaft measured by the main encoder (KTH7812) at the k-th sampling time.

[0046] In the speed loop, speed error for: in, The target velocity at the k-th sampling time (output by the position loop); The actual speed of the motor shaft is calculated by the auxiliary encoder at the k-th sampling time.

[0047] In the torque ring, It is the torque command at the kth sampling moment, which is sent to the motor driver as the final output of the controller; It is the actual torque measured by the torque sensor at the kth sampling time; It is the total disturbance torque estimated by the observer at the k-th sampling time, including load changes, friction, cogging effect, etc.

[0048] For the controller, For position controller; For speed controller; For disturbance observers.

[0049] The position loop is the outermost loop and has the slowest response. It determines the final steady-state accuracy of the system. The output of the position loop serves as the input (target velocity) to the velocity loop. in, It is the position loop proportional gain. Increasing this gain can improve the response speed, but too much gain can cause overshoot or oscillation. It is the position loop integral gain, used to eliminate steady position error; It is the position error integral from time 0 to time k.

[0050] The speed loop receives the target speed output from the position loop and tracks it quickly. As the outer loop of the current / torque loop, the speed loop is key to improving the response speed and stiffness of the entire system. in, It is the speed loop proportional gain, which affects the system's dynamic response and bandwidth; It is the speed loop integral gain, used to eliminate speed steady-state error and ensure that the speed remains stable when the load changes.

[0051] Nominal model torque for: in, It is the nominal model of the R-axis motor. It is the inverse model of the nominal model.

[0052] Actual control torque for: in, It is a feedforward term.

[0053] Estimate disturbance torque for: For estimating disturbance torque Perform low-pass filtering: in, It's a low-pass filter; high-frequency measurement noise is amplified by the inverse model, so a filter is needed to extract the effective low-frequency disturbance signal. The cutoff frequency determines the bandwidth of the disturbance that the observer can observe.

[0054] The observed disturbance is fed forward directly to the control output to actively counteract its effects: The total torque command sent to the R-axis motor is: Through a multi-loop + feedforward compensation architecture, the system can not only adjust based on error feedback, but also actively predict and counteract internal and external disturbances, thus achieving extremely high-precision position control even under high-speed and high-load changing conditions, perfectly meeting the needs of high-precision placement machines.

[0055] According to the high-precision fully closed-loop rotation control system for single-motor driven multi-nozzle rod provided in the embodiments of this application, the rotational position of the motor shaft is directly measured by an angle sensor to form a fully closed-loop control, thereby eliminating the errors caused by gear backlash, transmission belt elastic deformation and wear in traditional open-loop or semi-closed-loop control. Without occupying a lot of space and without increasing the XY load, the accuracy of the pick-and-place machine for mounting components is improved.

[0056] In some embodiments, the angle sensor includes a Hall element, an analog-to-digital converter (ADC) module, and an arctangent calculation (ATAN) module, which are connected in sequence via communication. The Hall element is used to generate a voltage signal based on the rotational position of the motor shaft; The analog-to-digital converter module is used to convert the voltage signal back into two orthogonal digital signals; The arctangent calculation module is used to determine the digital angle of the motor shaft based on the orthogonal digital information.

[0057] The Hall effect sensor of the angle sensor generates a voltage signal, which is converted into two orthogonal digital signals by the ADC. The internal ATAN module calculates the 16-bit digital angle. The MCU of the R-axis driver can obtain the current actual rotation angle of the R-axis through the SPI interface. This data is updated every 1µs and compared with the input signal to monitor and adjust the output of the R-axis in real time, thereby achieving higher precision control.

[0058] In some embodiments, the angle sensor is an off-axis magnetic encoder chip, model KTH7812.

[0059] It should be noted that SMT placement equipment needs to run at high speed continuously for a long time, and the working environment may be subject to vibration and slight contamination from solder paste, flux, and dust. Traditional optical encoders, based on gratings and photoelectric sensors, are extremely sensitive to contamination such as dust, grease, and moisture. Contaminants can block the light path, leading to signal loss, decreased accuracy, or even complete failure.

[0060] In this embodiment, the off-axis magnetic encoder chip operates by detecting changes in the magnetic field. The magnetic field is not affected by common non-magnetic contaminants, thus exhibiting extremely high reliability and environmental tolerance. This ensures continuous and stable operation on critical equipment such as SMT production lines, reducing maintenance costs.

[0061] In some embodiments, the angle sensor further includes a permanent magnet; The permanent magnet is sleeved on the gear between the suction nozzle rod and the motor shaft. The permanent magnet is arranged opposite to the Hall element. The air gap between the permanent magnet and the Hall element is set to 0.5mm-5mm. The installation deviation between the permanent magnet and the Hall element is set to 0.5mm-2mm.

[0062] like Figure 5 and Figure 6 As shown, the permanent magnet is a single-pole pair of magnets, such as neodymium iron boron or samarium cobalt, which is sleeved and fixed on the shaft of the transmission gear between the motor shaft and the nozzle rod.

[0063] The KTH7812 chip integrates a Hall element, a permanent magnet, an ADC module, and an ATAN module. The chip is fixedly mounted on a PCB board, with the sensing surface of the Hall element facing the magnetic pole face of the permanent magnet, maintaining a tiny air gap.

[0064] When the permanent magnet rotates with the gear shaft, the direction of the magnetic field around it changes synchronously; the Hall element senses the change in magnetic field and outputs two weak and orthogonal (90° phase difference) analog voltage signals. These two analog signals are sent to the ADC module and converted into two high-resolution orthogonal digital signals.

[0065] The digital signal is sent to the ATAN module, and the absolute digital angle value of the permanent magnet, i.e. the motor shaft, is calculated by executing the arctan2(sin,cos) function.

[0066] The air gap (AG) is controlled between 0.5mm and 5mm, and the displacement (DISP) is controlled between 0.5mm and 2mm. The installation tolerances of the permanent magnet and Hall element ensure the strength and linearity of the magnetic field signal, thus achieving high-precision measurement.

[0067] In some embodiments, the R-axis driver communicates with the angle sensor via a Serial Peripheral Interface (SPI).

[0068] The SPI interface used features high speed, full-duplex operation, and good signal synchronization, which can meet the requirements of high-precision real-time control for high-speed and low-latency feedback data. The R-axis driver, as the SPI master, periodically initiates read operations to the off-axis magnetic encoder chip, which acts as a slave device, to obtain the latest digital angle.

[0069] In this embodiment, a set of off-axis magnetic encoders is set up to provide feedback on the actual rotation angle of the R-axis, which is transmitted to the MCU of the R-axis driver via SPI. This achieves full closed-loop control, eliminates transmission backlash, and greatly improves the actual positioning accuracy of the rotary motor.

[0070] In some embodiments, such as Figure 7 As shown, the power supply terminal of the angle sensor is connected to the power supply terminal and grounded through two parallel 0.1μF capacitors.

[0071] In some embodiments, the clock pin (SCLK) of the microcontroller in the R-axis driver is connected to the clock pin (SCLK) of the angle sensor; the communication pin (CS) of the microcontroller in the R-axis driver is connected to the communication pin (CS) of the angle sensor; the data output pin (MOSI) of the microcontroller in the R-axis driver is connected to the data output pin (MOSI) of the angle sensor; the data input pin (MISO) of the microcontroller in the R-axis driver is connected to the data input pin (MISO) of the angle sensor; the three-phase power pins (U, V, W) of the microcontroller in the R-axis driver are respectively connected to the three-phase power pins (U, V, W) of the angle sensor through individual resistors in the first resistor assembly; and the Hall signal pins (A, B, C) of the microcontroller in the R-axis driver are respectively connected to the Hall signal pins (A, B, C) of the angle sensor through individual resistors in the second resistor assembly.

[0072] Each individual resistor in the first and second resistor assemblies is less than 200Ω.

[0073] In some embodiments, the clock pin, the communication pin, the data output pin, and the data input pin are respectively connected to the power supply terminal through individual resistors in the third resistor assembly; or, The clock pin, the communication pin, the data output pin, and the data input pin are all connected to the power supply terminal.

[0074] Each resistor in the third resistor assembly is 10kΩ.

[0075] like Figure 8 As shown, the high-precision fully closed-loop rotation control method for a single motor driving a multi-nozzle rod is applied to the high-precision fully closed-loop rotation control system for a single motor driving a multi-nozzle rod as described in any of the above embodiments. The method includes: Step 810: Acquire the rotational position of the motor shaft using an angle sensor, and generate a digital angle for the motor shaft; Step 820: Determine the actual rotation angle of the motor shaft using the R-axis driver based on the digital angle, and generate a drive signal based on the actual rotation angle and the angle setting value of the R-axis motor; Step 830: The R-axis motor responds to the drive signal and controls the mounting head to perform component placement via the motor shaft and the nozzle rod.

[0076] According to the high-precision fully closed-loop rotation control method for single-motor driven multi-nozzle rod provided in the embodiments of this application, the rotation position of the motor shaft is directly measured by an angle sensor to form a fully closed-loop control, thereby eliminating the errors caused by gear backlash, transmission belt elastic deformation and wear in traditional open-loop or semi-closed-loop control. Without occupying a lot of space and without increasing the XY load, the accuracy of the pick-and-place machine for mounting components is improved.

[0077] The high-precision fully closed-loop rotation control method for a single motor driving multiple suction nozzles provided in this application can be executed by a high-precision fully closed-loop rotation control device for a single motor driving multiple suction nozzles. This application uses the example of a high-precision fully closed-loop rotation control device for a single motor driving multiple suction nozzles to illustrate the high-precision fully closed-loop rotation control device for a single motor driving multiple suction nozzles provided in this application.

[0078] This application also provides a high-precision fully closed-loop rotation control device for a single motor driving multiple suction nozzle rods.

[0079] like Figure 9 As shown, this high-precision fully closed-loop rotation control device for single-motor driven multi-nozzle rods is used to control the high-precision fully closed-loop rotation control system for single-motor driven multi-nozzle rods as described in any of the above embodiments. The device includes: The first processing module 910 is used to acquire the rotational position of the motor shaft through an angle sensor and generate a digital angle of the motor shaft; The second processing module 920 is used to determine the actual rotation angle of the motor shaft based on the digital angle by the R-axis driver, and generate a drive signal based on the actual rotation angle and the angle setting value of the R-axis motor. The third processing module 930 is used to control the mounting head to perform component mounting by responding to the drive signal via the R-axis motor, through the motor shaft and the nozzle rod.

[0080] According to the embodiments of this application, the high-precision fully closed-loop rotation control device for single-motor driven multi-nozzle rod directly measures the rotational position of the motor shaft through an angle sensor to form a fully closed-loop control, thereby eliminating the errors caused by gear backlash, transmission belt elastic deformation and wear in traditional open-loop or semi-closed-loop control. It improves the accuracy of component placement by the pick-and-place machine without occupying a lot of space or increasing the XY load.

[0081] The high-precision fully closed-loop rotation control device for single-motor driven multi-nozzle rods in this application embodiment can be a device with an operating system. This operating system can be Android, iOS, or other possible operating systems; this application embodiment does not specifically limit it.

[0082] The high-precision fully closed-loop rotation control device for single-motor driven multi-nozzle rods provided in this application embodiment can realize the various processes implemented in the high-precision fully closed-loop rotation control method embodiment for single-motor driven multi-nozzle rods as described above. To avoid repetition, these processes will not be repeated here.

[0083] In some embodiments, such as Figure 10 As shown, this application embodiment also provides an electronic device 1000, including a processor 1001, a memory 1002, and a computer program stored in the memory 1002 and executable on the processor 1001. When the program is executed by the processor 1001, it implements the various processes of the above-described embodiment of the high-precision full closed-loop rotation control method for single motor driving multiple suction nozzle rods, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0084] It should be noted that the electronic devices in the embodiments of this application include the mobile electronic devices and non-mobile electronic devices described above.

[0085] This application also provides a non-transitory computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the various processes of the above-described high-precision fully closed-loop rotation control method embodiment for single-motor-driven multi-nozzle rods and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0086] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0087] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described high-precision fully closed-loop rotation control method for single-motor-driven multi-nozzle rods.

[0088] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0089] This application embodiment also provides a chip, which includes a processor and a communication interface. The communication interface and the processor are coupled. The processor is used to run programs or instructions to implement the various processes of the above-described high-precision full closed-loop rotation control method embodiment for single motor driving multiple suction nozzle rods, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0090] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0091] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0092] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the high-precision fully closed-loop rotation control method of single motor driving multi-nozzle rod of various embodiments of this application.

[0093] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

[0094] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0095] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A high-precision fully closed-loop rotation control system for a single motor driving a multi-nozzle rod, characterized in that, Includes R-axis motor, R-axis driver and angle sensor; The motor shaft of the R-axis motor is connected to the nozzle rod via a drive. The nozzle rod is equipped with a mounting head. The angle sensor is located on the rotation acquisition side of the motor shaft. The angle sensor is communicatively connected to the R-axis driver. The R-axis driver is communicatively connected to the R-axis motor. The angle sensor is used to acquire the rotational position of the motor shaft and generate a digital angle of the motor shaft; The R-axis driver is used to determine the actual rotation angle of the motor shaft based on the digital angle, and to generate a drive signal based on the actual rotation angle and the angle setting value of the R-axis motor. The R-axis motor is used to respond to the drive signal and control the mounting head to perform component placement via the motor shaft and the nozzle rod.

2. The high-precision fully closed-loop rotation control system for single-motor driven multi-nozzle rods according to claim 1, characterized in that, The angle sensor includes a Hall element, an analog-to-digital conversion module, and an arctangent calculation module, which are connected in sequence via communication. The Hall element is used to generate a voltage signal based on the rotational position of the motor shaft; The analog-to-digital converter module is used to convert the voltage signal back into two orthogonal digital signals; The arctangent calculation module is used to determine the digital angle of the motor shaft based on the orthogonal digital information.

3. The high-precision fully closed-loop rotation control system for single-motor driven multi-nozzle rods according to claim 2, characterized in that, The angle sensor is an off-axis magnetic encoder chip, model KTH7812.

4. The high-precision fully closed-loop rotation control system for single-motor driven multi-nozzle rods according to claim 2, characterized in that, The angle sensor also includes a permanent magnet; The permanent magnet is sleeved on the gear between the suction nozzle rod and the motor shaft. The permanent magnet is arranged opposite to the Hall element. The air gap between the permanent magnet and the Hall element is set to 0.5mm-5mm. The installation deviation between the permanent magnet and the Hall element is set to 0.5mm-2mm.

5. The high-precision fully closed-loop rotation control system for single-motor driven multi-nozzle rods according to claim 1, characterized in that, The R-axis driver communicates with the angle sensor via a serial peripheral interface.

6. The high-precision fully closed-loop rotation control system for single-motor driven multi-nozzle rods according to claim 5, characterized in that, In the R-axis driver, the clock pin of the microcontroller is connected to the clock pin of the angle sensor, the communication pin of the microcontroller is connected to the communication pin of the angle sensor, the data output pin of the microcontroller is connected to the data output pin of the angle sensor, the data input pin of the microcontroller is connected to the data input pin of the angle sensor, and the three-phase power pins of the microcontroller in the R-axis driver are respectively connected to the three-phase power pins of the angle sensor through the resistors in the first resistor assembly. In the R-axis driver, the Hall signal pins of the microcontroller are connected to the Hall signal pins of the angle sensor through individual resistors in the second resistor assembly.

7. The high-precision fully closed-loop rotation control system for single-motor driven multi-nozzle rods according to claim 6, characterized in that, The clock pin, the communication pin, the data output pin, and the data input pin are each connected to the power supply terminal via individual resistors in the third resistor assembly; or, The clock pin, the communication pin, the data output pin, and the data input pin are all connected to the power supply terminal.

8. A high-precision fully closed-loop rotation control method for a single motor driving a multi-nozzle rod, characterized in that, The method, applied to the high-precision fully closed-loop rotation control system for a single motor driving a multi-nozzle rod as described in any one of claims 1-7, comprises: The rotational position of the motor shaft is acquired by an angle sensor, and a digital angle of the motor shaft is generated. The R-axis driver determines the actual rotation angle of the motor shaft based on the digital angle, and generates a drive signal based on the actual rotation angle and the angle setting value of the R-axis motor. The R-axis motor responds to the drive signal, and the mounting head is controlled by the motor shaft and the nozzle rod to perform component mounting.

9. A high-precision fully closed-loop rotation control device for a single motor driving a multi-nozzle rod, characterized in that, The device for controlling the high-precision fully closed-loop rotation control system for a single motor driving a multi-nozzle rod as described in any one of claims 1-7 includes: The first processing module is used to acquire the rotational position of the motor shaft through an angle sensor and generate a digital angle of the motor shaft; The second processing module is used to determine the actual rotation angle of the motor shaft based on the digital angle using the R-axis driver, and to generate a drive signal based on the actual rotation angle and the angle setting value of the R-axis motor. The third processing module is used to control the mounting head to perform component mounting by responding to the drive signal via the R-axis motor, through the motor shaft and the nozzle rod.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the high-precision fully closed-loop rotation control method for single-motor driven multi-nozzle rods as described in any one of claims 1-7.

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