A brushless motor lifting table control system and method based on RS485 bus communication

Abstract

The application discloses a brushless motor lifting table control system and method based on RS485 bus type communication, and the system comprises a power supply unit connected with alternating current mains and comprising a plurality of general interfaces; an operation unit connected with the power supply unit through the general interfaces and used for outputting control instructions and receiving feedback signals; and a driving unit connected with a motor and connected with the power supply unit through the general interfaces and used for controlling the motor according to the received control signals and outputting feedback signals. The substantial effects of the application include: the driving unit of the motor is separated from the integrated control box, the integrated control box is simplified into the power supply unit with only switching power supplies, and the overall volume of the control box is reduced; RS485 bus type communication is adopted, the electric physical interface definition is unified, and users can connect in any order; and the application has high expansibility.

Description

Technical Field

[0001] This invention relates to the field of motor control, and in particular to a control system and method for a brushless motor lifting table based on RS485 bus communication. Background Technology

[0002] Traditional height-adjustable desk control systems almost entirely employ integrated control boxes for direct control. These boxes integrate the power supply and motor driver, connecting the hand controller, motor, and control unit. The electrical connections between the motor and control box include: motor phase wire, hall signal wire, and hall power wire. All motors used are brushed motors.

[0003] The electrical connection between the motor and the integrated control box requires at least the motor phase wire, the hall signal wire, and the hall power wire. The large number of interface wires and the large size result in a large size of the integrated control box. The motor drive needs to be implemented by the main control MCU. When there are many motors, the pin resources of the main control MCU are consumed in a huge way, and the available resources for expansion are limited, resulting in very low expandability. Summary of the Invention

[0004] To address the issues of large size, high cost, and poor scalability in existing technologies, this invention provides a brushless motor lifting table control system and method based on RS485 bus communication. The motor drive circuit of the main control board of the integrated controller is separated and connected to the power supply unit using a universal interface, which greatly improves scalability and reduces the size of the power supply unit.

[0005] The following is the technical solution of the present invention.

[0006] A brushless motor lifting desk control system based on RS485 bus communication includes:

[0007] The power supply unit connects to AC mains power and includes several general-purpose interfaces;

[0008] The operation unit is connected to the power supply unit via a general interface and is used to output control commands and receive feedback signals;

[0009] The drive unit connects to the motor and is connected to the power supply unit via a universal interface. It is used to control the motor according to the received control signals and output feedback signals.

[0010] The universal interface of this invention allows all external devices to be plugged in in any order, greatly improving scalability.

[0011] Preferably, the universal interface includes four pins: pin1—GND, pin2—VBUS, pin3—485-A, and pin4—485-B; wherein pins with the same number are connected through an OR resistor between all universal interfaces of the same power supply unit.

[0012] Preferably, there are multiple power supply units, which are connected through a common interface. This allows for scalable power output, preventing performance degradation due to insufficient power under heavy load conditions; it also allows for scalability of the number of controlled motors, eliminating the pin resource limitations of a single power supply unit's MCU.

[0013] This invention also provides a control method for a brushless motor height-adjustable desk based on RS485 bus communication, comprising the following steps:

[0014] A control system including a power supply unit, an operation unit, and a drive unit is pre-built. Each motor is assigned an ID and networked. The drive unit in the control system controls the motors with different IDs separately according to the control commands with IDs issued by the operation unit, and returns feedback signals to the operation unit.

[0015] After receiving the feedback signal, the operation unit adjusts the control commands according to the requirements to complete the control of the lifting table.

[0016] Since this solution is used in a height-adjustable desk system, all columns need to operate or stop simultaneously, and the height of all desk legs must remain consistent throughout the column raising and lowering process. Therefore, it is essential to have individual control capabilities for each motor. This method assigns an ID to each motor, enabling individual control of different motors, thereby ensuring synchronized control of desk leg heights and meeting special adjustment requirements.

[0017] Preferably, assigning an ID to each motor includes compressing the universally unique identifier (UUID) corresponding to each motor into a lower-bit encoded value as the motor's ID. The STM32 processor comes with a built-in 96-bit (12-byte) UUID (Universally Unique Identifier). While this code is unique, 96 bits is too long and unsuitable for direct transmission as an ID in communication protocols; therefore, compression is necessary.

[0018] Preferably, the lower-order encoded value is a 32-bit CRC value, and the compression algorithm used is the CRC32 algorithm. 32 bits can represent a maximum of 4,294,967,295 different node IDs, and the probability of repetition can be considered zero.

[0019] Preferably, the networking includes the following steps: the control unit sends a networking broadcast command, and after receiving the networking broadcast command, the drive unit uses a preset delay response mechanism to calculate the corresponding delay value based on the ID of each motor, and the drive unit sends the corresponding motor ID to the control unit after a delay based on the delay value.

[0020] Preferably, the preset delayed response mechanism is an ID segment selection Mod190 delayed response mechanism, which includes: splitting the 32-bit ID into 4 segments, each segment being represented by an 8-bit binary number, with bits 0-7 being segment 1, bits 8-15 being segment 2, bits 16-23 being segment 3, and bits 24-31 being segment 4, and the value range of each segment being 0-255; during network formation, the control unit sends a network broadcast command with a specified segment selection value, and after receiving this command, the drive unit selects the corresponding ID segment from the 32-bit ID according to the segment selection value and performs a mod 190 operation, with the result being 0-189, and the motor ID is sent to the control unit with different delays depending on the different operation results. Because the system needs to be scalable and allow for flexible insertion of motors, the motors cannot be differentiated by hardware (such as using DIP switches to create hardware differences) to form a network. Instead, a pure software mechanism must be used to ensure that each motor on the bus sends its ID to the control unit in an orderly manner. If IDs are sent at the same time, the bus data will be mixed up, causing the control unit to not receive any valid IDs. The "ID segment selection Mod190 delay reply mechanism" used in this solution can ensure the high efficiency of the network.

[0021] Preferably, if motors with different IDs produce the same result when performing a mod 190 operation on the same segment selection value, the control unit will reselect the segment selection value and execute a preset delay response mechanism. If necessary, the segment selection value will be traversed from 0 to 3 to prevent two or more motors from having the same mod 190 result for a specific ID segment, which could lead to simultaneous ID responses and cause bus data aliasing.

[0022] The substantial effects of this invention include: separating the motor drive unit from the integrated control box, simplifying the integrated control box to a power supply unit containing only a switching power supply, and reducing the overall size of the control box; adopting RS485 bus communication, with unified definition of electrical physical interfaces, allowing users to connect and disconnect in any order; and having high scalability. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the system connection according to an embodiment of the present invention;

[0024] Figure 2 This is a pin definition diagram of an embodiment of the present invention;

[0025] Figure 3 This is a diagram showing the mod 190 calculation result of an embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of the delayed response mechanism in an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] It should be understood that in the various embodiments of the present invention, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0029] It should be understood that in this invention, "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0030] It should be understood that in this invention, "B corresponding to A", "B corresponding to A", "A and B correspond", or "B and A correspond" means that B is associated with A, and B can be determined based on A. Determining B based on A does not mean determining B solely based on A; B can also be determined based on A and / or other information. Matching A and B is defined as a similarity between A and B that is greater than or equal to a preset threshold.

[0031] The technical solution of the present invention will be described in detail below with reference to specific embodiments. Embodiments may be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0032] Example:

[0033] A brushless motor lifting desk control system based on RS485 bus communication, such as Figure 1 As shown, it includes:

[0034] The power supply unit connects to AC mains power and includes several general-purpose interfaces;

[0035] The operator, connected to the power supply unit via a universal interface, is used to output control commands and receive feedback signals;

[0036] The drive board connects to the motor and is connected to the power supply unit via a universal interface. It is used to control the motor according to the received control signals and output feedback signals.

[0037] like Figure 2 As shown, the general interface includes four pins: pin1—GND, pin2—VBUS, pin3—485-A, and pin4—485-B; pins with the same number are connected to all general interfaces in the same power supply unit through an OR resistor.

[0038] This embodiment uses multiple power supply units, which are connected through a common interface. This allows for scalable power output, preventing performance degradation due to insufficient power under heavy system load conditions; it also enables scalability of the number of controlled motors, eliminating the pin resource limitations of a single power supply unit MCU.

[0039] This embodiment also provides a brushless motor height-adjustable desk control method based on RS485 bus communication, including the following steps:

[0040] A control system including a power supply unit, an operator, and a drive board is pre-built. Each motor is assigned an ID and networked. The ID assignment for each motor includes: using the CRC32 algorithm, compressing the 96-bit universal unique identifier (UUID) corresponding to each motor into a 32-bit CRC value with the lower bit as the motor ID.

[0041] Network setup includes: the control unit sends a network broadcast command, and after receiving the network broadcast command, the driver board uses a preset delay response mechanism to calculate the corresponding delay value based on the ID of each motor. The driver board then sends the corresponding motor ID to the control unit after a delay based on the delay value.

[0042] The preset delayed response mechanism is an ID segment selection Mod190 delayed response mechanism, which includes: splitting the 32-bit ID into 4 segments, each segment represented by an 8-bit binary number. Bits 0-7 are segment 1, bits 8-15 are segment 2, bits 16-23 are segment 3, and bits 24-31 are segment 4. The value range of each segment is 0-255. When networking, the control unit sends a network broadcast command with a specified segment selection value. After receiving this command, the driver board selects the corresponding ID segment from the 32-bit ID according to the segment selection value and performs a mod 190 operation. The result of the operation is 0-189. Depending on the different results, the motor ID is sent to the control unit after a different delay. Because the system needs to be scalable and allow for flexible insertion of motors, the motors cannot be differentiated by hardware (such as using DIP switches to create hardware differences) to form a network. Instead, a pure software mechanism must be used to ensure that each motor on the bus sends its ID to the control unit in an orderly manner. If IDs are sent at the same time, the bus data will be aliased, causing the control unit to fail to receive any valid IDs. The "ID segment selection Mod190 delay reply mechanism" used in this solution can ensure the high efficiency of the network.

[0043] like Figure 3 and Figure 4 As shown, if motors with different IDs produce the same result when performing a mod 190 operation on the same segment selection value, the control unit will reselect the segment selection value and execute a preset delay response mechanism. If necessary, the segment selection value will be traversed from 0 to 3 to prevent two or more motors from having the same mod 190 result for a specific ID segment, which could lead to simultaneous ID responses and cause bus data aliasing.

[0044] The drive board in the control system controls motors with different IDs separately according to the control commands with IDs issued by the operator, and returns feedback signals to the operator.

[0045] After receiving the feedback signal, the operator adjusts the control commands according to the requirements to complete the control of the height-adjustable table.

[0046] Since this solution is used for height-adjustable desk systems, all columns need to operate or stop simultaneously, and the height of all desk legs must remain consistent throughout the lifting process. Therefore, individual control capability for each motor is essential. This method assigns an ID to each motor, enabling individual control of different motors, thereby ensuring synchronized control of the desk corners and meeting special adjustment requirements.

[0047] In this embodiment, the physical layer of the communication interface constituting the bus network can be changed from RS485 to RS232 or CAN. Alternatively, the controlled component can be replaced with a brushed motor.

[0048] This embodiment separates the motor drive unit from the integrated control box, simplifying the integrated control box into a power supply unit containing only a switching power supply, thus reducing the overall size of the control box; it adopts RS485 bus communication, with unified physical interface definitions for electrical appliances, allowing users to connect and disconnect them in any order; and it has high scalability.

[0049] Through the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the specific device can be divided into different functional modules to complete all or part of the functions described above.

[0050] In the embodiments provided in this application, it should be understood that the disclosed structures and methods can be implemented in other ways. For example, the structural embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another structure, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between structures or units, and may be electrical, mechanical, or other forms.

[0051] The units described as separate components may or may not be physically separate. A component shown as a unit can be one or more physical units; that is, it can be located in one place or distributed in multiple different locations. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0052] Furthermore, in the embodiments of this application, the functional units can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0053] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, in essence, or the parts that contribute to the prior art, or all or part of the technical solutions, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0054] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A brushless motor lifting table control system based on RS485 bus communication, characterized in that, include: The power supply unit connects to AC mains power and includes several general-purpose interfaces; The operation unit is connected to the power supply unit via a general interface and is used to output control commands and receive feedback signals; The drive unit connects to the motor and is connected to the power supply unit via a universal interface. It is used to control the motor according to the received control signals and output feedback signals. The drive unit is also used to: assign an ID to each motor and network it. The network includes the following steps: the control unit sends a network broadcast command, and after receiving the network broadcast command, the drive unit uses a preset delay response mechanism to calculate the corresponding delay value based on the ID of each motor. The drive unit then sends the corresponding motor ID to the control unit after a delay based on the delay value. Assigning an ID to each motor includes: compressing the universally unique identifier (UUID) corresponding to each motor into a lower-bit encoded value as the motor's ID; The lower-order encoded value is a 32-bit CRC value, and the compression algorithm used is the CRC32 algorithm; The preset delayed response mechanism is an ID segment selection Mod190 delayed response mechanism, which includes: splitting the 32-bit ID into 4 segments, each segment represented by an 8-bit binary number, bits 0-7 being segment 1, bits 8-15 being segment 2, bits 16-23 being segment 3, and bits 24-31 being segment 4, with each segment having a value range of 0-255; during network formation, the control unit sends a network broadcast command with a specified segment selection value, and after receiving this command, the drive unit selects the corresponding ID segment from the 32-bit ID according to the segment selection value and performs a mod 190 operation, with the result being 0-189, and the motor ID is sent to the control unit with different delays depending on the different operation results.

2. The brushless motor lifting table control system based on RS485 bus communication according to claim 1, characterized in that, The general interface includes four pins: pin1—GND, pin2—VBUS, pin3—485-A, and pin4—485-B; pins with the same number are connected through an OR resistor between all general interfaces of the same power supply unit.

3. The brushless motor lifting table control system based on RS485 bus communication according to claim 2, characterized in that, There are multiple power supply units, which are connected to each other through a common interface.

4. A control method for a brushless motor-driven height-adjustable desk based on RS485 bus communication, characterized in that, Includes the following steps: A control system including a power supply unit, an operation unit, and a drive unit is pre-built, and each motor is assigned an ID and networked. The drive unit in the control system controls motors with different IDs separately according to the control commands with IDs issued by the operation unit, and returns feedback signals to the operation unit. After receiving the feedback signal, the operation unit adjusts the control commands according to the requirements to complete the control of the lifting table; The networking process includes the following steps: the control unit sends a networking broadcast command, and after receiving the networking broadcast command, the drive unit uses a preset delay response mechanism to calculate the corresponding delay value based on the ID of each motor. The drive unit then sends the corresponding motor ID to the control unit after a delay based on the delay value. Assigning an ID to each motor includes: compressing the universally unique identifier (UUID) corresponding to each motor into a lower-bit encoded value as the motor's ID; The lower-order encoded value is a 32-bit CRC value, and the compression algorithm used is the CRC32 algorithm; The preset delayed response mechanism is an ID segment selection Mod190 delayed response mechanism, which includes: splitting the 32-bit ID into 4 segments, each segment represented by an 8-bit binary number, bits 0-7 being segment 1, bits 8-15 being segment 2, bits 16-23 being segment 3, and bits 24-31 being segment 4, with each segment having a value range of 0-255; during network formation, the control unit sends a network broadcast command with a specified segment selection value, and after receiving this command, the drive unit selects the corresponding ID segment from the 32-bit ID according to the segment selection value and performs a mod 190 operation, with the result being 0-189, and the motor ID is sent to the control unit with different delays depending on the different operation results.

5. A brushless motor lifting table control method based on RS485 bus communication according to claim 4, characterized in that, If motors with different IDs produce the same result when performing a mod 190 operation under the same segment selection value, the control unit will reselect the segment selection value and execute the preset delay response mechanism.

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